Author name code: narukage
ADS astronomy entries on 2022-09-14
author:"Narukage, Noriyuki" 
------------------------------------------------------------------------  

Title: Quiet Sun Center to Limb Variation of the Linear Polarization
    Observed by CLASP2 Across the Mg II h and k Lines
Authors: Rachmeler, L. A.; Bueno, J. Trujillo; McKenzie, D. E.;
   Ishikawa, R.; Auchère, F.; Kobayashi, K.; Kano, R.; Okamoto,
   T. J.; Bethge, C. W.; Song, D.; Ballester, E. Alsina; Belluzzi,
   L.; Pino Alemán, T. del; Ramos, A. Asensio; Yoshida, M.; Shimizu,
   T.; Winebarger, A.; Kobelski, A. R.; Vigil, G. D.; Pontieu, B. De;
   Narukage, N.; Kubo, M.; Sakao, T.; Hara, H.; Suematsu, Y.; Štěpán,
   J.; Carlsson, M.; Leenaarts, J.
Bibcode: 2022ApJ...936...67R
Altcode: 2022arXiv220701788R
  The CLASP2 (Chromospheric LAyer Spectro-Polarimeter 2) sounding rocket
  mission was launched on 2019 April 11. CLASP2 measured the four Stokes
  parameters of the Mg II h and k spectral region around 2800 Å along a
  200″ slit at three locations on the solar disk, achieving the first
  spatially and spectrally resolved observations of the solar polarization
  in this near-ultraviolet region. The focus of the work presented here
  is the center-to-limb variation of the linear polarization across these
  resonance lines, which is produced by the scattering of anisotropic
  radiation in the solar atmosphere. The linear polarization signals of
  the Mg II h and k lines are sensitive to the magnetic field from the
  low to the upper chromosphere through the Hanle and magneto-optical
  effects. We compare the observations to theoretical predictions
  from radiative transfer calculations in unmagnetized semiempirical
  models, arguing that magnetic fields and horizontal inhomogeneities
  are needed to explain the observed polarization signals and spatial
  variations. This comparison is an important step in both validating and
  refining our understanding of the physical origin of these polarization
  signatures, and also in paving the way toward future space telescopes
  for probing the magnetic fields of the solar upper atmosphere via
  ultraviolet spectropolarimetry.

Title: Study of Time Evolution of Thermal and Nonthermal Emission
    from an M-class Solar Flare
Authors: Nagasawa, Shunsaku; Kawate, Tomoko; Narukage, Noriyuki;
   Takahashi, Tadayuki; Caspi, Amir; Woods, Thomas N.
Bibcode: 2022ApJ...933..173N
Altcode: 2022arXiv220514369N
  We conduct a wide-band X-ray spectral analysis in the energy range
  of 1.5-100 keV to study the time evolution of the M7.6-class flare
  of 2016 July 23, with the Miniature X-ray Solar Spectrometer (MinXSS)
  CubeSat and the Reuven Ramaty High Energy Solar Spectroscopic Imager
  (RHESSI) spacecraft. With the combination of MinXSS for soft X-rays and
  RHESSI for hard X-rays, a nonthermal component and three-temperature
  multithermal component-"cool" (T ≍ 3 MK), "hot" (T ≍ 15 MK), and
  "superhot" (T ≍ 30 MK)-were measured simultaneously. In addition,
  we successfully obtained the spectral evolution of the multithermal
  and nonthermal components with a 10 s cadence, which corresponds to
  the Alfvén timescale in the solar corona. We find that the emission
  measures of the cool and hot thermal components are drastically
  increasing more than hundreds of times and the superhot thermal
  component is gradually appearing after the peak of the nonthermal
  emission. We also study the microwave spectra obtained by the Nobeyama
  Radio Polarimeters, and we find that there is continuous gyrosynchrotron
  emission from mildly relativistic nonthermal electrons. In addition,
  we conducted a differential emission measure (DEM) analysis by using
  Atmospheric Imaging Assembly on board the Solar Dynamics Observatory
  and determined that the DEM of cool plasma increases within the flaring
  loop. We find that the cool and hot plasma components are associated
  with chromospheric evaporation. The superhot plasma component could
  be explained by the thermalization of the nonthermal electrons trapped
  in the flaring loop.

Title: On the faintest solar coronal hard X-rays observed with FOXSI
Authors: Buitrago-Casas, Juan Camilo; Glesener, Lindsay; Christe,
   Steven; Krucker, Säm; Vievering, Juliana; Athiray, P. S.; Musset,
   Sophie; Davis, Lance; Courtade, Sasha; Dalton, Gregory; Turin,
   Paul; Turin, Zoe; Ramsey, Brian; Bongiorno, Stephen; Ryan, Daniel;
   Takahashi, Tadayuki; Furukawa, Kento; Watanabe, Shin; Narukage,
   Noriyuki; Ishikawa, Shin-nosuke; Mitsuishi, Ikuyuki; Hagino, Kouichi;
   Shourt, Van; Duncan, Jessie; Zhang, Yixian; Bale, Stuart D.
Bibcode: 2022arXiv220504291B
Altcode:
  Solar nanoflares are small eruptive events releasing magnetic energy in
  the quiet corona. If nanoflares follow the same physics as their larger
  counterparts, they should emit hard X-rays (HXRs) but with a rather
  faint intensity. A copious and continuous presence of nanoflares would
  deliver enormous amounts of energy into the solar corona, possibly
  accounting for its high temperatures. To date, there has not been
  any direct observation of such sustained and persistent HXRs from the
  quiescent Sun. However, Hannah et al. in 2010 constrained the quiet
  Sun HXR emission using almost 12 days of quiescent solar-off-pointing
  observations by RHESSI. These observations set upper limits at
  $3.4\times 10^{-2}$ photons$^{-1}$ s$^{-1}$ cm$^{-2}$ keV$^{-1}$
  and $9.5\times 10^{-4}$ photons$^{-1}$ s$^{-1}$ cm$^{-2}$ keV$^{-1}$
  for the 3-6 keV and 6-12 keV energy ranges, respectively. Observing
  feeble HXRs is challenging because it demands high sensitivity
  and dynamic range instruments in HXRs. The Focusing Optics X-ray
  Solar Imager (FOXSI) sounding rocket experiment excels in these
  two attributes. Particularly, FOXSI completed its third successful
  flight (FOXSI-3) on September 7th, 2018. During FOXSI-3's flight,
  the Sun exhibited a fairly quiet configuration, displaying only one
  aged non-flaring active region. Using the entire $\sim$6.5 minutes of
  FOXSI-3 data, we constrained the quiet Sun emission in HXRs. We found
  $2\sigma$ upper limits in the order of $\sim 10^{-3}$ photons$^{-1}$
  s$^{-1}$ cm$^{-2}$ keV$^{-1}$ for the 5-10 keV energy range. FOXSI-3's
  upper limit is consistent with what was reported by Hannah et al.,
  2010, but FOXSI-3 achieved this result using $\sim$1/2640 less time
  than RHESSI. A possible future spacecraft using FOXSI's concept would
  allow enough observation time to constrain the current HXR quiet Sun
  limits further or perhaps even make direct detections.

Title: Empirical relations between the intensities of Lyman lines
    of H and He<SUP>+</SUP>
Authors: Gordino, M.; Auchère, F.; Vial, J. -C.; Bocchialini, K.;
   Hassler, D. M.; Bando, T.; Ishikawa, R.; Kano, R.; Kobayashi, K.;
   Narukage, N.; Trujillo Bueno, J.; Winebarger, A.
Bibcode: 2022A&A...657A..86G
Altcode: 2022arXiv220101519G
  Context. Empirical relations between major UV and extreme UV spectral
  lines are one of the inputs for models of chromospheric and coronal
  spectral radiances and irradiances. They are also needed for the
  interpretation of some of the observations of the Solar Orbiter
  mission. <BR /> Aims: We aim to determine an empirical relation between
  the intensities of the H I 121.6 nm and He II 30.4 nm Ly-α lines. <BR
  /> Methods: Images at 121.6 nm from the Chromospheric Lyman-Alpha
  Spectro Polarimeter (CLASP) and Multiple XUV Imager (MXUVI) sounding
  rockets were co-registered with simultaneous images at 30.4 nm from the
  EIT and AIA orbital telescopes in order to derive a spatially resolved
  relationship between the intensities. <BR /> Results: We have obtained
  a relationship between the H I 121.6 nm and He II 30.4 nm intensities
  that is valid for a wide range of solar features, intensities, and
  activity levels. Additional SUMER data have allowed the derivation of
  another relation between the H I 102.5 nm (Ly-β) and He II 30.4 nm
  lines for quiet-Sun regions. We combined these two relationships to
  obtain a Ly-α/Ly-β intensity ratio that is comparable to the few
  previously published results. <BR /> Conclusions: The relationship
  between the H I 121.6 nm and He II 30.4 nm lines is consistent with the
  one previously obtained using irradiance data. We have also observed
  that this relation is stable in time but that its accuracy depends on
  the spatial resolution of the observations. The derived Ly-α/Ly-β
  intensity ratio is also compatible with previous results.

Title: Hard X-ray upper limits of the quiet Sun with new FOXSI
    observations
Authors: Buitrago-Casas, Juan Camilo; Glesener, Lindsay; Christe,
   Steven; Krucker, Sam; Vievering, Juliana; Athiray, P. S.; Musset,
   Sophie; Davis, Lance; Courtade, Sasha; Dalton, Gregory; Turin,
   Paul; Turin, Zoe; Ramsey, Brian; Bongiorno, Stephen; Ryan, Daniel;
   Takahashi, Tadayuki; Furukawa, Kento; Watanabe, Shin; Narukage,
   Noriyuki; Ishikawa, Shin-nosuke; Mitsuishi, Ikuyuki; Hagino, Kouichi
Bibcode: 2021AGUFMSH51A..04B
Altcode:
  Solar nanoflares are small eruptive events releasing magnetic energy
  in the quiet corona. If nanoflares follow the same physics as their
  larger counterparts, they should emit hard X-rays (HXRs) but with a
  rather faint intensity. A copious and continuous presence of nanoflares
  would result in a sustained and persistent emission in HXRs, which in
  turn would deliver enormous amounts of energy into the solar corona,
  possibly accounting for its high temperatures. To date, there has not
  been any direct observation of such sustained and persistent HXRs from
  the quiescent Sun. However, Hannah et al. in 2010 constrained the quiet
  Sun HXR emission using almost 12 days of quiescent solar-off-pointing
  observations by RHESSI. These observations set $2\sigma$ upper limits
  at $3.4\times 10^{-2}$ photons$^{-1}$ s$^{-1}$ cm$^{-2}$ keV$^{-1}$
  and $9.5\times 10^{-4}$ photons$^{-1}$ s$^{-1}$ cm$^{-2}$ keV$^{-1}$
  for the 3-6 keV and 6-12 keV energy ranges, respectively. Observing
  feeble HXRs is challenging because it demands high sensitivity and
  dynamic range instruments in the HXR energy band. The Focusing Optics
  X-ray Solar Imager (FOXSI) sounding rocket experiment excels in these
  two attributes when compared with RHESSI. Particularly, FOXSI completed
  its third successful flight (FOXSI-3) on September 7th, 2018. During
  FOXSI-3s flight, the Sun exhibited a fairly quiet configuration,
  displaying only one aged non-flaring active region. Using the entire
  $\sim$6.5 minutes of FOXSI-3 data, we constrained the quiet Sun emission
  in HXRs. We found $2\sigma$ upper limits in the order of $\sim 10^{-3}$
  photons$^{-1}$ s$^{-1}$ cm$^{-2}$ keV$^{-1}$ for the 5-10 keV energy
  range. FOXSI-3's upper limit is consistent with what was reported by
  Hannah et al., 2010, but FOXSI-3 achieved this result using $\sim$1/2640
  less time than RHESSI. A possible future spacecraft using FOXSI's
  concept would allow enough observation time to constrain the current
  HXR quiet Sun limits further or perhaps even make direct detections.

Title: The FOXSI-4 Sounding Rocket: High Resolution Focused X-ray
    Observations of the Sun
Authors: Glesener, Lindsay; Buitrago-Casas, Juan Camilo; Vievering,
   Juliana; Pantazides, Athanasios; Musset, Sophie; Panchapakesan,
   Subramania Athiray; Baumgartner, Wayne; Bongiorno, Stephen; Champey,
   Patrick; Christe, Steven; Courtade, Sasha; Duncan, Jessie; Ishikawa,
   Shin-nosuke; Krucker, Sam; Martinez Oliveros, Juan Carlos; Perez-Piel,
   Savannah; Mitsuishi, Ikuyuki; Narukage, Noriyuki; Ryan, Daniel;
   Takahashi, Tadayuki; Watanabe, Shin
Bibcode: 2021AGUFMSH55B1831G
Altcode:
  It has been firmly demonstrated that direct-focusing instruments
  can transform the way high-energy X-rays from astronomical objects,
  including the Sun, are measured. The NuSTAR spacecraft has increased the
  sensitivity to faint astrophysical sources by 100 times as compared with
  previous, indirect, imagers. The first three flights of the Focusing
  Optics X-ray Solar Imager (FOXSI) sounding rocket established the
  usefulness and feasibility of a similar method optimized for the Sun,
  and showed that in addition to greater sensitivity, a vastly improved
  dynamic range can be obtained in this way. This technology stands
  ready to revolutionize understanding of solar flares by elucidating
  particle acceleration sites in the corona, studying how electrons
  propagate and deposit their energies, and how accelerated particles
  escape into interplanetary space. While the fundamental building
  blocks of solar hard X-ray (HXR) focusing are in place and ready for a
  spacecraft mission, concurrent development is required to prepare for
  the next generation of high-energy solar explorers, which will require
  higher rate capability and higher angular resolution to investigate
  finer-scale structure and to better complement instruments at other
  wavelengths. FOXSI-4 features technological advances that enable
  high angular resolution as well as measurement of bright sources. In
  the first category, we will develop high-precision mirror production
  methods and finely pixelated Si CMOS sensors, and will demonstrate
  substrip/subpixel resolution in fine-pitch CdTe sensors. Secondly,
  we will demonstrate rate capability of these sensors sufficient
  for flare measurement, and will develop novel pixelated attenuators
  that optimize energy coverage even at high rates. The experiment will
  demonstrate these technologies in NASAs first-ever solar flare campaign,
  flying in tandem with the Hi-C FLARE rocket and in a campaign with the
  SNIFS rocket. The campaign will position multiple rocket experiments
  awaiting an opportunistic signal and will launch the experiments for
  near-simultaneous observation of the flare.This campaign will allow
  for direct collaboration with the Parker Solar Probe (PSP) during one
  of its perihelia.

Title: FOXSI-4: the high resolution focusing X-ray rocket payload
    to observe a solar flare
Authors: Buitrago-Casas, Juan Camilo; Vievering, Juliana; Musset,
   Sophie; Glesener, Lindsay; Athiray, P. S.; Baumgartner, Wayne;
   Bongiorno, Stephen; Champey, Patrick; Christe, Steven; Courtade,
   Sasha; Dalton, Gregory; Duncan, Jessie; Gilchrist, Kelsey; Ishikawa,
   Shin-nosuke; Jhabvala, Christine; Kanniainen, Hunter; Krucker,
   Säm.; Gregory, Kyle; Martinez Oliveros, Juan Carlos; McCracken,
   Jeff; Mitsuishi, Ikuyuki; Narukage, Noriyuki; Pantazides, Athanasios;
   Peretz, Eliad; Perez-Piel, Savannah; Ramanayaka, Aruna; Ramsey, Brian;
   Ryan, Danny; Savage, Sabrina; Takahashi, Tadayuki; Watanabe, Shin;
   Winebarger, Amy; Zhang, Yixian
Bibcode: 2021SPIE11821E..0LB
Altcode:
  The FOXSI-4 sounding rocket will fly a significantly upgraded instrument
  in NASA's first solar are campaign. It will deploy direct X-ray focusing
  optics which have revolutionized our understanding of astrophysical
  phenomena. For example, they have allowed NuSTAR to provide X-ray
  imaging and IXPE (scheduled for launch in 2021) to provide X-ray
  polarization observations with detectors with higher photon rate
  capability and greater sensitivity than their predecessors. The FOXSI
  sounding rocket is the first solar dedicated mission using this method
  and has demonstrated high sensitivity and improved imaging dynamic range
  with its three successful flights. Although the building blocks are
  already in place for a FOXSI satellite instrument, further advances are
  needed to equip the next generation of solar X-ray explorers. FOXSI-4
  will develop and implement higher angular resolution optics/detector
  pairs to investigate fine spatial structures (both bright and faint)
  in a solar are. FOXSI-4 will use highly polished electroformed Wolter-I
  mirrors fabricated at the NASA/Marshall Space Flight Center (MSFC),
  together with finely pixelated Si CMOS sensors and fine-pitch CdTe strip
  detectors provided by a collaboration with institutes in Japan. FOXSI-4
  will also implement a set of novel perforated attenuators that will
  enable both the low and high energy spectral components to be observed
  simultaneously in each pixel, even at the high rates expected from a
  medium (or large) size solar are. The campaign will take place during
  one of the Parker Solar Probe (PSP) perihelia, allowing coordination
  between this spacecraft and other instruments which observe the Sun
  at different wavelengths.

Title: Assessing quiet Sun hard X-rays using observations from the
    FOXSI Sounding Rockets
Authors: Buitrago-Casas, J.; Glesener, L.; Christe, S.; Krucker,
   S.; Vievering, J.; Athiray, P.; Musset, S.; Ryan, D.; Ishikawa, S.;
   Narukage, N.; Bongiorno, S.; Furukawa, K.; Ramsey, B.; Courtade, S.;
   Dalton, G.; Turin, P.; Takahashi, T.; Watanabe, S.; Mitsuishi, I.;
   Hagino, K.; Duncan, J.
Bibcode: 2021AAS...23810604B
Altcode:
  In solar and helio-physics, the coronal heating problem relates to the
  question of identifying and explaining the mechanism(s) causing the
  corona's temperatures to be a few hundred times hotter than the solar
  surface. Among the various plausible hypotheses proposed to explain
  this problem, one of the strongest candidates relates to copious low
  energy magnetic reconnections (nanoflares) occurring throughout the
  solar corona. When examined thoroughly, this mechanism implies heating
  that happens impulsively on individual flux tubes (strands). Emission
  of hard X-rays (HXRs) should be a consequence of such non-thermal
  phenomena, or even of purely thermal transients, if hot enough. In
  quiescent solar corona areas, nanoflares should manifest in HXRs via
  very faint signatures covering vast regions. Observing feeble HXRs
  demands an instrument with high sensitivity and dynamic range for
  energies between 4 and 15 keV. FOXSI (which stands for the Focusing
  Optics X-ray Solar Imager) is such an instrument. As a payload of
  a NASA/LCAS (low-cost access to space program) sounding rocket,
  FOXSI has successfully completed three launches. The two most recent
  flights (FOXSI-2 and -3) included quiescent areas of the Sun as part
  of the targets. For this presentation, we will show a full assessment
  of the HXR flux from the quiet Sun observed with FOXSI. We begin by
  presenting a thorough characterization of the stray light (ghost rays)
  impinging into FOXSI's detectors caused by sources outside of the field
  of view. We then identify areas free of ghost rays where the instrument
  sensitivity reaches a maximum to quiet Sun HXR detections. Finally,
  we implement a Bayesian (known as ON/OFF analysis) to estimate an upper
  detectability threshold of quiet Sun HXRs and a probability distribution
  for quiet-Sun HXR fluxes when sources are supposed to exist.

Title: Mapping of Solar Magnetic Fields from the Photosphere to the
    Top of the Chromosphere with CLASP2
Authors: McKenzie, D.; Ishikawa, R.; Trujillo Bueno, J.; Auchere, F.;
   del Pino Aleman, T.; Okamoto, T.; Kano, R.; Song, D.; Yoshida, M.;
   Rachmeler, L.; Kobayashi, K.; Narukage, N.; Kubo, M.; Ishikawa, S.;
   Hara, H.; Suematsu, Y.; Sakao, T.; Bethge, C.; De Pontieu, B.; Vigil,
   G.; Winebarger, A.; Alsina Ballester, E.; Belluzzi, L.; Stepan, J.;
   Asensio Ramos, A.; Carlsson, M.; Leenaarts, J.
Bibcode: 2021AAS...23810603M
Altcode:
  Coronal heating, chromospheric heating, and the heating &amp;
  acceleration of the solar wind, are well-known problems in solar
  physics. Additionally, knowledge of the magnetic energy that
  powers solar flares and coronal mass ejections, important drivers
  of space weather, is handicapped by imperfect determination of the
  magnetic field in the sun's atmosphere. Extrapolation of photospheric
  magnetic measurements into the corona is fraught with difficulties and
  uncertainties, partly due to the vastly different plasma beta between
  the photosphere and the corona. Better results in understanding
  the coronal magnetic field should be derived from measurements of
  the magnetic field in the chromosphere. To that end, we are pursuing
  quantitative determination of the magnetic field in the chromosphere,
  where plasma beta transitions from greater than unity to less than
  unity, via ultraviolet spectropolarimetry. The CLASP2 mission, flown
  on a sounding rocket in April 2019, succeeded in measuring all four
  Stokes polarization parameters in UV spectral lines formed by singly
  ionized Magnesium and neutral Manganese. Because these ions produce
  spectral lines under different conditions, CLASP2 thus was able to
  quantify the magnetic field properties at multiple heights in the
  chromosphere simultaneously, as shown in the recent paper by Ishikawa
  et al. In this presentation we will report the findings of CLASP2,
  demonstrating the variation of magnetic fields along a track on
  the solar surface and as a function of height in the chromosphere;
  and we will illustrate what is next for the CLASP missions and the
  demonstration of UV spectropolarimetry in the solar chromosphere.

Title: High Resolution FOXSI: The Development Of FOXSI-4
Authors: Glesener, L.; Buitrago-Casas, J.; Duncan, J.; Nagasawa, S.;
   Pantazides, A.; Perez-Piel, S.; Zhang, Y.; Vievering, J.; Musset,
   S.; Panchapakesan, S.; Baumgartner, W.; Bongiorno, S.; Champey, P.;
   Christe, S.; Courtade, S.; Kanniainen, H.; Krucker, S.; Ishikawa,
   S.; Martinez Oliveros, J.; Mitsuishi, I.; Narukage, N.; Peretz, E.;
   Ryan, D.; Takahashi, T.; Watanabe, S.; Winebarger, A.
Bibcode: 2021AAS...23831301G
Altcode:
  It has been firmly demonstrated that direct-focusing instruments
  can transform the way high-energy X-rays from astronomical objects,
  including the Sun, are measured. The NuSTAR spacecraft has increased the
  sensitivity to faint astrophysical sources by 100 times as compared with
  previous, indirect, imagers. The first three flights of the Focusing
  Optics X-ray Solar Imager (FOXSI) sounding rocket established the
  usefulness and feasibility of a similar method optimized for the Sun,
  and showed that in addition to greater sensitivity, a vastly improved
  dynamic range can be obtained in this way. This technology stands
  ready to revolutionize understanding of solar flares by elucidating
  particle acceleration sites in the corona, studying how electrons
  propagate and deposit their energies, and how accelerated particles
  escape into interplanetary space. While the fundamental building
  blocks of solar hard X-ray (HXR) focusing are in place and ready for
  a spacecraft mission, concurrent development is required to prepare
  for a subsequent generation of high-energy solar explorers, which
  will require higher rate capability and higher angular resolution to
  investigate finer-scale structure and to better complement instruments
  at other wavelengths.The fourth flight of FOXSI (FOXSI-4) features
  technological advances that enable high angular resolution as well as
  measurement of bright sources. In the first category, we are developing
  high-precision mirror production methods and finely pixelated Si CMOS
  sensors, and will demonstrate substrip/subpixel resolution in fine-pitch
  CdTe sensors. Secondly, we will demonstrate a rate capability of these
  sensors sufficient for flare measurement, and are developing novel
  pixelated attenuators that optimize energy coverage even at high
  rates.The experiment will demonstrate these technologies in NASA's
  first-ever solar flare campaign, flying in tandem with the Hi-C FLARE
  rocket and on the same campaign as the SNIFS rocket. The campaign will
  position multiple rocket experiments awaiting an opportunistic signal
  and will launch multiple payloads for near-simultaneous observation
  of the flare.This campaign will allow for direct collaboration with
  the Parker Solar Probe (PSP) during one of its perihelia.

Title: Mapping solar magnetic fields from the photosphere to the
    base of the corona
Authors: Ishikawa, Ryohko; Bueno, Javier Trujillo; del Pino Alemán,
   Tanausú; Okamoto, Takenori J.; McKenzie, David E.; Auchère,
   Frédéric; Kano, Ryouhei; Song, Donguk; Yoshida, Masaki; Rachmeler,
   Laurel A.; Kobayashi, Ken; Hara, Hirohisa; Kubo, Masahito; Narukage,
   Noriyuki; Sakao, Taro; Shimizu, Toshifumi; Suematsu, Yoshinori; Bethge,
   Christian; De Pontieu, Bart; Dalda, Alberto Sainz; Vigil, Genevieve D.;
   Winebarger, Amy; Ballester, Ernest Alsina; Belluzzi, Luca; Štěpán,
   Jiří; Ramos, Andrés Asensio; Carlsson, Mats; Leenaarts, Jorrit
Bibcode: 2021SciA....7.8406I
Altcode: 2021arXiv210301583I
  Routine ultraviolet imaging of the Sun's upper atmosphere shows the
  spectacular manifestation of solar activity; yet we remain blind to
  its main driver, the magnetic field. Here we report unprecedented
  spectropolarimetric observations of an active region plage and
  its surrounding enhanced network, showing circular polarization in
  ultraviolet (Mg II $h$ &amp; $k$ and Mn I) and visible (Fe I) lines. We
  infer the longitudinal magnetic field from the photosphere to the
  very upper chromosphere. At the top of the plage chromosphere the
  field strengths reach more than 300 gauss, strongly correlated with
  the Mg II $k$ line core intensity and the electron pressure. This
  unique mapping shows how the magnetic field couples the different
  atmospheric layers and reveals the magnetic origin of the heating in
  the plage chromosphere.

Title: Optical design of the Chromospheric LAyer Spectro-Polarimeter
    (CLASP2)
Authors: Tsuzuki, Toshihiro; Ishikawa, Ryohko; Kano, Ryouhei; Narukage,
   Noriyuki; Song, Donguk; Yoshida, Masaki; Uraguchi, Fumihiro; Okamoto,
   Takenori J.; McKenzie, David; Kobayashi, Ken; Rachmeler, Laurel;
   Auchere, Frederic; Trujillo Bueno, Javier
Bibcode: 2020SPIE11444E..6WT
Altcode:
  Chromospheric LAyer Spectro-Polarimeter (CLASP2) was a sounding
  rocket experiment, which is a follow-up mission to the Chromospheric
  Lyman-Alpha Spectro-Polarimeter (CLASP1) in 2015. To measure the
  magnetic fields in the upper solar atmosphere in a highly quantitative
  manner, CLASP2 changes the target wavelengths from the hydrogen Ly-α
  line (121.567 nm) to Mg II lines near 280 nm. We reused the main
  structure and most of the optical components in the CLASP1 instrument,
  which reduced the turnaround time and cost. We added a magnifying
  optical system to maintain the wavelength resolution, even at the
  longer wavelength of CLASP2. Here, we describe the optical design and
  performance of the CLASP2 instrument.

Title: The FOXSI-4 Sounding Rocket: High Resolution Focused X-ray
    Observations of the Sun
Authors: Glesener, L.; Buitrago-Casas, J. C.; Musset, S.; Vievering,
   J. T.; Athiray, P. S.; Baumgartner, W.; Bongiorno, S.; Champey, P. R.;
   Christe, S.; Courtade, S.; Duncan, J. M.; Ishikawa, S. N.; Krucker,
   S.; Martinez Oliveros, J. C.; Mitsuishi, I.; Narukage, N.; Ryan, D.;
   Takahashi, T.; Watanabe, S.; Winebarger, A. R.
Bibcode: 2020AGUFMSH0480011G
Altcode:
  It has been firmly demonstrated that direct-focusing instruments
  can transform the way high-energy X-rays from astronomical objects,
  including the Sun, are measured. The NuSTAR spacecraft has increased the
  sensitivity to faint astrophysical sources by 100 times as compared with
  previous, indirect, imagers. The first three flights of the Focusing
  Optics X-ray Solar Imager (FOXSI) sounding rocket established the
  usefulness and feasibility of a similar method optimized for the Sun,
  and showed that in addition to greater sensitivity, a vastly improved
  dynamic range can be obtained in this way. This technology stands
  ready to revolutionize understanding of solar flares by elucidating
  particle acceleration sites in the corona, studying how electrons
  propagate and deposit their energies, and how accelerated particles
  escape into interplanetary space. While the fundamental building
  blocks of solar hard X-ray (HXR) focusing are in place and ready for a
  spacecraft mission, concurrent development is required to prepare for
  the next generation of high-energy solar explorers, which will require
  higher rate capability and higher angular resolution to investigate
  finer-scale structure and to better complement instruments at other
  wavelengths. <P />FOXSI-4 features technological advances that enable
  high angular resolution as well as measurement of bright sources. In
  the first category, we will develop high-precision mirror production
  methods and finely pixelated Si CMOS sensors, and will demonstrate
  substrip/subpixel resolution in fine-pitch CdTe sensors. Secondly,
  we will demonstrate rate capability of these sensors sufficient for
  flare measurement, and will develop novel pixelated attenuators that
  optimize energy coverage even at high rates. <P />The experiment
  will demonstrate these technologies in NASA's first-ever solar flare
  campaign, flying in tandem with the Hi-C FLARE rocket. The campaign will
  position multiple rocket experiments awaiting an opportunistic signal
  and will launch the experiments for near-simultaneous observation of
  the flare.This campaign will allow for direct collaboration with the
  Parker Solar Probe (PSP) during one of its perihelia.

Title: Limits on the X-ray emission of the quiet Sun from the FOXSI
    sounding rockets
Authors: Buitrago-Casas, J. C.; Glesener, L.; Christe, S.; Krucker,
   S.; Vievering, J. T.; Athiray, P. S.; Musset, S.; Ryan, D.; Ishikawa,
   S. N.; Narukage, N.; Bongiorno, S.; Furukawa, K.; Ramsey, B.; Davis,
   L.; Courtade, S.; Dalton, G.; Turin, P.; Turin, Z.; Takahashi, T.;
   Watanabe, S.; Mitsuishi, I.; Hagino, K.; Duncan, J. M.
Bibcode: 2020AGUFMSH0430002B
Altcode:
  Nanoflares are a potential solution for the coronal heating problem. In
  the quiet Sun, nanoflares should exhibit hard X-ray (HXR) signatures
  manifested to an observer via either i) a single HXR kernel or
  ii) HXRs from many flares spread all over the Sun. In both cases,
  detecting nanoflare HXRs requires an instrument with superior dynamic
  range and sensitivity in the ~4 to 15 keV energy range over previous
  solar dedicated HXR telescopes, like RHESSI. The Focusing Optics
  X-ray Solar Imager (FOXSI) fulfills these requirements. FOXSI has
  successfully flown on three sounding rocket campaigns; the last two
  (FOXSI-2 and -3) included the observation of quiet areas of the solar
  disk. For FOXSI-3, several techniques were tested and developed to
  minimize a background effect unique to hard X-ray focusing optics,
  frequently referred to as ghost rays. <P />In this presentation, we
  provide, for the first time, a FOXSI sounding rocket assessment of the
  HXR flux from the quiet Sun. To fully characterize the sensitivity
  of FOXSI, we assessed ghost rays generated by sources outside of
  the field of view via a ray-tracing algorithm. This is particularly
  important for observations from FOXSI-2 when techniques to minimize
  ghost rays were not implemented yet. Using the ray tracing tool, we
  identify areas free of ghost rays that contribute to the background
  and therefore have maximum sensitivity to quiet Sun HXR emission. We
  use a bayesian approach to provide upper thresholds of quiet Sun HXR
  emission and probability distributions for the expected flux when a
  quiet-Sun HXR source is assumed to exist. We compare this result with
  prior constraints such as that made by RHESSI (Hannah et al. 2010).

Title: Use of a ray-tracing simulation to characterize ghost rays
    in the FOXSI rocket experiment
Authors: Buitrago-Casas, J. C.; Christe, S.; Glesener, L.; Krucker,
   S.; Ramsey, B.; Bongiorno, S.; Kilaru, K.; Athiray, P. S.; Narukage,
   N.; Ishikawa, S.; Dalton, G.; Courtade, S.; Musset, S.; Vievering,
   J.; Ryan, D.; Bale, S.
Bibcode: 2020JInst..15P1032B
Altcode: 2020arXiv201007049B
  Imaging X-rays by direct focusing offers greater sensitivity and
  a higher dynamic range compared to techniques based on indirect
  imaging. The Focusing Optics X-ray Solar Imager (FOXSI) is a
  sounding rocket payload that uses seven sets of nested Wolter-I
  figured mirrors to observe the Sun in hard X-rays through direct
  focusing. Characterizing the performance of these optics is critical
  to optimize their performance and to understand their resulting
  data. In this paper, we present a ray-tracing simulation we created and
  developed to study Wolter-I X-ray mirrors. We validated the accuracy
  of the ray-tracing simulation by modeling the FOXSI rocket optics. We
  found satisfactory agreements between the simulation predictions
  and laboratory data measured on the optics. We used the ray-tracing
  simulation to characterize a background pattern of singly reflected
  rays (i.e., ghost rays) generated by photons at certain incident
  angles reflecting on only one of a two-segment Wolter-I figure and
  still reaching the focal plane. We used the results of the ray-tracing
  simulation to understand, and to formulate a set of strategies that
  can be used to mitigate, the impact of ghost rays on the FOXSI optical
  modules. These strategies include the optimization of aperture plates
  placed at the entrance and exit of the smallest Wolter-I mirror used
  in FOXSI, a honeycomb type collimator, and a wedge absorber placed
  at the telescope aperture. The ray-tracing simulation proved to be
  a reliable set of tools to study Wolter-I X-ray optics. It can be
  used in many applications, including astrophysics, material sciences,
  and medical imaging.

Title: Inverse First Ionization Potential Effects in Giant Solar
    Flares Found from Earth X-Ray Albedo with Suzaku/XIS
Authors: Katsuda, Satoru; Ohno, Masanori; Mori, Koji; Beppu, Tatsuhiko;
   Kanemaru, Yoshiaki; Tashiro, Makoto S.; Terada, Yukikatsu; Sato,
   Kosuke; Morita, Kae; Sagara, Hikari; Ogawa, Futa; Takahashi, Haruya;
   Murakami, Hiroshi; Nobukawa, Masayoshi; Tsunemi, Hiroshi; Hayashida,
   Kiyoshi; Matsumoto, Hironori; Noda, Hirofumi; Nakajima, Hiroshi;
   Ezoe, Yuichiro; Tsuboi, Yohko; Maeda, Yoshitomo; Yokoyama, Takaaki;
   Narukage, Noriyuki
Bibcode: 2020ApJ...891..126K
Altcode: 2020arXiv200110643K
  We report X-ray spectroscopic results for four giant solar flares
  that occurred on 2005 September 7 (X17.0), 2005 September 8 (X5.4),
  2005 September 9 (X6.2), and 2006 December 5 (X9.0), obtained from
  Earth albedo data with the X-ray Imaging Spectrometer (XIS) on board
  Suzaku. The good energy resolution of the XIS (FWHM ∼ 100 eV) enables
  us to separate a number of line-like features and detect the underlying
  continuum emission. These features include Si Heα, Si Lyα, S Heα,
  S Lyα, Ar Heα, and Ca Heα originating from solar flares as well as
  fluorescent Ar Kα and Ar Kβ from the Earth's atmosphere. Absolute
  elemental abundances (X/H) averaged over the four flares are obtained
  to be ∼2.0 (Ca), ∼0.7 (Si), ∼0.3 (S), and ∼0.9 (Ar) at around
  flare peaks. This abundance pattern is similar to those of active
  stars' coronae showing inverse first ionization potential (I-FIP)
  effects, I.e., elemental abundances decrease with decreasing FIP
  with a turnover at the low end of the FIP. The abundances are almost
  constant during the flares, with the exception of Si which increases by
  a factor of ∼2 in the decay phase. The evolution of the Si abundance
  is consistent with the finding that the I-FIP plasma originates from
  chromospheric evaporation and then mixes with the surrounding low-FIP
  biased materials. Flare-to-flare abundance varied by a factor of two,
  agreeing with past observations of solar flares. Finally, we emphasize
  that Earth albedo data acquired by X-ray astronomy satellites like
  Suzaku and the X-Ray Imaging Spectroscopy Mission can significantly
  contribute to studies of solar physics.

Title: FOXSI-2 Solar Microflares. I. Multi-instrument Differential
    Emission Measure Analysis and Thermal Energies
Authors: Athiray, P. S.; Vievering, Juliana; Glesener, Lindsay;
   Ishikawa, Shin-nosuke; Narukage, Noriyuki; Buitrago-Casas, Juan
   Camilo; Musset, Sophie; Inglis, Andrew; Christe, Steven; Krucker,
   Säm; Ryan, Daniel
Bibcode: 2020ApJ...891...78A
Altcode: 2020arXiv200204200A
  In this paper we present the differential emission measures
  (DEMs) of two sub-A class microflares observed in hard X-rays
  (HXRs) by the FOXSI-2 sounding rocket experiment, on 2014 December
  11. The second Focusing Optics X-ray Solar Imager (FOXSI) flight
  was coordinated with instruments X-ray Telescope (Hinode/XRT) and
  Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA), which
  provided observations in soft X-rays and Extreme Ultraviolet. This
  unique data set offers an unprecedented temperature coverage,
  useful for characterizing the plasma temperature distribution
  of microflares. By combining data from FOXSI-2, XRT, and AIA, we
  determined a well-constrained DEM for the microflares. The resulting
  DEMs peak around 3 MK and extend beyond 10 MK. The emission measures
  determined from FOXSI-2 were lower than 10<SUP>26</SUP> cm<SUP>-5</SUP>
  for temperatures higher than 5 MK; faint emission in this range is best
  measured in HXRs. The coordinated FOXSI-2 observations produce one of
  the few definitive measurements of the distribution and the amount
  of plasma above 5 MK in microflares. We utilize the multi-thermal
  DEMs to calculate the amount of thermal energy released during both
  the microflares as ∼5.0 × 10<SUP>28</SUP> erg for Microflare 1
  and ∼1.6 × 10<SUP>28</SUP> erg for Microflare 2. We also show the
  multi-thermal DEMs provide more comprehensive thermal energy estimates
  than isothermal approximation, which systematically underestimates
  the amount of thermal energy released.

Title: Estimating the Temperature and Density of a Spicule from 100
    GHz Data Obtained with ALMA
Authors: Shimojo, Masumi; Kawate, Tomoko; Okamoto, Takenori J.;
   Yokoyama, Takaaki; Narukage, Noriyuki; Sakao, Taro; Iwai, Kazumasa;
   Fleishman, Gregory D.; Shibata, Kazunari
Bibcode: 2020ApJ...888L..28S
Altcode: 2019arXiv191205714S
  We succeeded in observing two large spicules simultaneously with the
  Atacama Large Millimeter/submillimeter Array (ALMA), the Interface
  Region Imaging Spectrograph (IRIS), and the Atmospheric Imaging Assembly
  (AIA) on board the Solar Dynamics Observatory. One is a spicule seen
  in the IRIS Mg II slit-jaw images and AIA 304 Å images (Mg II/304 Å
  spicule). The other one is a spicule seen in the 100 GHz images obtained
  with ALMA (100 GHz spicule). Although the 100 GHz spicule overlapped
  with the Mg II/304 Å spicule in the early phase, it did not show any
  corresponding structures in the IRIS Mg II and AIA 304 Å images after
  the early phase. It suggests that the spicules are individual events and
  do not have a physical relationship. To obtain the physical parameters
  of the 100 GHz spicule, we estimate the optical depths as a function
  of temperature and density using two different methods. One is using
  the observed brightness temperature by assuming a filling factor,
  and the other is using an emission model for the optical depth. As a
  result of comparing them, the kinetic temperature of the plasma and
  the number density of ionized hydrogen in the 100 GHz spicule are
  ∼6800 K and 2.2 × 10<SUP>10</SUP> cm<SUP>-3</SUP>. The estimated
  values can explain the absorbing structure in the 193 Å image, which
  appear as a counterpart of the 100 GHz spicule. These results suggest
  that the 100 GHz spicule presented in this Letter is classified to a
  macrospicule without a hot sheath in former terminology.

Title: FOXSI-4: Instrument Upgrades for a Proposed Fourth Focusing
    Optics X-Ray Solar Imager Sounding Rocket Experiment
Authors: Vievering, J. T.; Glesener, L.; Buitrago-Casas, J. C.;
   Panchapakesan, S. A.; Musset, S.; Duncan, J. M.; Narukage, N.; Ryan,
   D.; Inglis, A. R.; Takahashi, T.; Watanabe, S.; Christe, S.; Krucker,
   S.; Turin, P.; Ramsey, B.
Bibcode: 2019AGUFMSH31C3315V
Altcode:
  Observations of the Sun in hard X-rays can provide insight into many
  solar phenomena, including the mechanisms behind energy release and
  transport in flares. The indirect imaging methods used by RHESSI ,
  the previous state-of-the-art solar hard X-ray instrument, however,
  were fundamentally limited in sensitivity and imaging dynamic range . By
  instead using the direct imaging technique of focusing hard X-rays, the
  structure and evolution of faint coronal sources, including microflares,
  active regions, and flare acceleration sites, can be investigated in
  greater depth. FOXSI ( Focusing Optics X-ray Solar Imager ), a hard
  X-ray instrument flown on three sounding rocket campaigns to date,
  seeks to achieve these improved capabilities by using focusing optics
  for solar observations in the 4-20 keV range. A fourth FOXSI sounding
  rocket experiment, FOXSI-4, has been proposed for launch in 2023,
  and the planned instrument upgrades are presented here. One main
  focus of FOXSI-4 will be to improve the angular resolution for solar
  hard X-ray instruments through the use of high-resolution optics,
  with the goal of reaching a half power diameter (HPD) of ∼5". Higher
  resolution will allow for individual footpoints and acceleration sites
  to be distinguished during a flare, which would benefit studies of the
  chromospheric response and provide constraints on flare acceleration
  mechanisms. FOXSI-4 will ideally be part of a flare campaign, in which
  multiple solar sounding rockets would be launched one after another
  to demonstrate the strength of new solar technologies when utilized
  in conjunction for flare observations.

Title: Hardware upgrades and science outcomes from the latest flights
    of the FOXSI rocket
Authors: Buitrago-Casas, J. C.; Glesener, L.; Courtade, S.; Vievering,
   J. T.; Athiray, P. S.; Musset, S.; Ryan, D.; Dalton, G.; Ishikawa,
   S. N.; Narukage, N.; Bongiorno, S.; Furukawa, K.; Davis, L.; Turin,
   P.; Turin, Z.; Takahashi, T.; Watanabe, S.; Krucker, S.; Christe,
   S.; Ramsey, B.
Bibcode: 2019AGUFMSH31C3316B
Altcode:
  FOXSI (which stands for the Focusing Optics X-ray Solar Imager)
  is a sounding rocket payload that has completed three successful
  flights supported by the Low-Cost Access to Space (LCAS) program of
  NASA. FOXSI stands out for being the first telescope optimized to use
  direct focusing to perform imaging spectroscopy of solar hard X-rays
  (HXRs). We present the latest instrument upgrades incorporated into
  the rocket payload for its third flight. We highlight the way these
  upgrades substantially improved the telescope performance and we
  present the observations obtained. Particularly, we describe the
  strategies implemented to reduce stray-light (ghost-ray) background
  and the inclusion of a soft X-ray CMOS sensor as well as HXR CdTe
  strip detectors to widen the spectral range of the telescope. <P
  />We finalize with an overview of the science results of the FOXSI
  flights. We present a differential emission measure (DEM) and thermal
  analyses of microflares observed during the second flight. We prove
  the relevance of the FOXSI measurements for obtaining unprecedented
  constrained microflare DEMs and discuss their implications on the
  energetics of these small flaring events. We finish presenting a
  discussion on the FOXSI measurements of an aged active region and
  quiet-sun areas observed during its latest flight.

Title: Characterization of Charge Sharing in the FOXSI Sounding Rocket
    Hard X-ray Detectors Using the Advanced Light Source at Berkeley
Authors: Duncan, J. M.; Panchapakesan, S. A.; Musset, S.; Vievering,
   J. T.; MacDowell, A. A.; Glesener, L.; Davis, L.; Buitrago-Casas,
   J. C.; O'Brien, C.; Ishikawa, S. N.; Takahashi, T.; Watanabe, S.;
   Narukage, N.; Furukawa, K.; Ryan, D.; Hagino, K.; Courtade, S.;
   Christe, S.; Krucker, S.
Bibcode: 2019AGUFMSH31C3317D
Altcode:
  The FOXSI sounding rocket experiments represent the first ever
  solar-dedicated direct-focusing hard X-ray (HXR) instruments. The
  most recent flight (FOXSI-3) occurred in September 2018, utilizing
  Wolter-1 style concentric-shell optics and both silicon (Si) and
  cadmium telluride (CdTe) double-sided strip detectors. The angular
  resolution of the optics (5" FWHM, equivalent to 50um at the detector
  bench) is finer than the strip pitch of the Si and CdTe detectors
  (75um and 60um, respectively), meaning that the resolution of the
  instrument at sounding rocket focal lengths is detector-limited
  [1]. In order to further improve characterization of the spatial and
  spectral properties of the FOXSI-3 detectors, experiments were recently
  completed using Beamline 3.3.2. at the Advanced Light Source (ALS)
  at Lawrence Berkeley National Laboratory. Using this beamline, a fine
  (2um x 2um or 5um x 5um) monoenergetic x-ray beam was scanned across
  detector strips and inter-strip regions in steps much smaller than the
  strip pitch. Such scans were performed for both Si and CdTe detectors
  at a number of x-ray energies between 5.5-12 keV. These experiments were
  particularly motivated by the desire to measure the incidence of charge
  sharing, which occurs when a single incident photon causes signals
  to be registered in multiple adjacent strips. Precise measurement of
  charge sharing behavior is important to optimize characterization of
  detector efficiency. Additionally, with a strong understanding of
  charge sharing behavior in a detector, spatial resolution could be
  improved by sub-strip localization of photon impacts. Here, we present
  initial analysis of results from these ALS experiments, including
  investigation into charge sharing properties in both the Si and CdTe
  FOXSI-3 detectors. We also discuss the implications of these results
  for the use of these detectors in the future FOXSI-4 mission, which
  will utilize yet-higher-resolution HXR optics. <P />[1] Furukawa,K.,et
  al. "Development of 60um pitch CdTe Double-sided Strip Detectors for
  the FOXSI-3 sounding rocket experiment." NIMPR, Section A: HSTD11, 2017.

Title: High-frequency Wave Propagation Along a Spicule Observed
    by CLASP
Authors: Yoshida, Masaki; Suematsu, Yoshinori; Ishikawa, Ryohko;
   Okamoto, Takenori J.; Kubo, Masahito; Kano, Ryouhei; Narukage,
   Noriyuki; Bando, Takamasa; Winebarger, Amy R.; Kobayashi, Ken;
   Trujillo Bueno, Javier; Auchère, Frédéric
Bibcode: 2019ApJ...887....2Y
Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) sounding
  rocket experiment, launched in 2015 September, observed the hydrogen
  Lyα line (121.6 nm) in an unprecedented high temporal cadence of
  0.3 s. CLASP performed sit-and-stare observations of the quiet Sun
  near the limb for 5 minutes with a slit perpendicular to the limb
  and successfully captured an off-limb spicule evolving along the
  slit. The Lyα line is well suited for investigating how spicules
  affect the corona because it is sensitive to higher temperatures than
  other chromospheric lines, owing to its large optical thickness. We
  found high-frequency oscillations of the Doppler velocity with periods
  of 20-50 s and low-frequency oscillation of periods of ∼240 s on
  the spicule. From a wavelet analysis of the time sequence data of
  the Doppler velocity, in the early phase of the spicule evolution,
  we found that waves with a period of ∼30 s and a velocity amplitude
  of 2-3 km s<SUP>-1</SUP> propagated upward along the spicule with a
  phase velocity of ∼470 km s<SUP>-1</SUP>. In contrast, in the later
  phase, possible downward and standing waves with smaller velocity
  amplitudes were also observed. The high-frequency waves observed in
  the early phase of the spicule evolution would be related with the
  dynamics and the formation of the spicules. Our analysis enabled us to
  identify the upward, downward, and standing waves along the spicule
  and to obtain the velocity amplitude of each wave directly from the
  Doppler velocity for the first time. We evaluated the energy flux
  by the upward-propagating waves along the spicule, and discussed the
  impact to the coronal heating.

Title: Satellite mission: PhoENiX (Physics of Energetic and
    Non-thermal plasmas in the X (= magnetic reconnection) region)
Authors: Narukage, N.
Bibcode: 2019AGUFMSH31C3311N
Altcode:
  We are planning a new solar satellite mission, "PhoENiX", for
  understanding of particle acceleration during magnetic reconnection. The
  main observation targets of this mission are solar flares, which are
  generated by magnetic reconnection and accelerate plasma particles. <P
  />The scientific objectives of this mission are (1) to identify
  particle acceleration sites, (2) to investigate temporal evolution
  of particle acceleration, and (3) to characterize properties of
  accelerated particles, during solar flares. In order to achieve these
  science objectives, the PhoENiX satellite is planned to be equipped
  with three instruments of (1) Photon-counting type focusing-imaging
  spectrometer in soft X-rays (up to ~10 keV) to observe the contexts
  of particle accelerations (e.g., shocks, plasmoids, flows, etc.),
  (2) Photon-counting type focusing-imaging spectrometer in hard
  X-rays (up to ~30 keV) to identify the accelerated particles, and (3)
  Spectropolarimeter in soft gamma-rays (spectroscopy is available in the
  energy range of from &gt; 20 keV to &lt; 600 keV; spectropolarimetry is
  available from &gt; 60 keV to &lt; 600 keV) to detect the anisotropy of
  accelerated particles. We plan to realize the PhoENiX satellite mission
  around next solar maximum (around 2025). <P />The basic developments
  of key technologies for these instruments have been completed. The
  soft X-ray imaging spectroscopy is planned to be realized with
  the combination of high-precision glass-polished X-ray mirrors and
  high-speed CMOS cameras. The hard X-ray imaging spectroscopy consists
  of high-precision electroforming X-ray mirrors and CdTe cameras. The
  soft gamma-ray spectropolarimeter is a redesigned instrument of
  Hitomi / Soft Gamma-ray Detector (SGD) that has Compton cameras with
  active shields. Some of these technologies have been demonstrated
  by FOXSI sounding rocket series launched in 2012, 2014 and 2018. The
  4th flight of FOXSI sounding rocket is being proposed for the X-ray
  imaging spectroscopic observation of the solar flare with high spatial
  resolution. This is a good opportunity to demonstrate the PhoENiX
  satellite in the both point of views of science and technology. In this
  presentation, we explain the details of science goal and objectives,
  and instruments of the PhoENiX mission.

Title: The Solar High-Resolution X-ray imager (SHRX): A Concept for
    a Sounding Rocket Experiment
Authors: Champey, P. R.; Savage, S. L.; Winebarger, A. R.; Broadway,
   D.; Kobayashi, K.; Davis, J.; Kolodziejczak, J.; Griffith, C.;
   Narukage, N.
Bibcode: 2019AGUFMSH31C3318C
Altcode:
  The evolution and spatial distribution of small-scale, high-temperature
  plasma structures in the solar corona can be used to address multiple
  open science questions, including how the corona is dynamically heated,
  and how tremendous amounts of energy are released within seconds during
  eruptive events. Despite decades of imaging this plasma in X-rays,
  the spatial resolution of available grazing incidence mirrors has
  constrained our understanding of this important energy regime. High
  temperature plasma can be imaged in the extreme ultraviolet (EUV)
  using normal incidence telescopes, which can be more-readily fabricated
  to meet high resolution requirements. Multi-layers can be implemented
  to limit the narrow passband to select for EUV wavelengths containing
  high temperature emission lines. The EUV spectrum, however, contains
  cooler emission lines that inevitably contaminate high temperature
  channels. Here, we present a design concept for a high-resolution,
  (&lt; 1 arcsecond) soft X-ray (SXR) imager to fly aboard a sounding
  rocket that will enable solar observations of small-scale structures
  containing plasma greater than 5 million degrees. The Solar High
  Resolution X-ray imager (SHRX) will observe a narrow SXR band centered
  at 1.03 keV (12 Angstroms) using cutting-edge multi-layer coatings and
  an improved glass substrate grazing incidence mirror developed at NASA
  Marshall Space Flight Center (MSFC). The optical design accommodates
  a CMOS detector developed by the Japan Aerospace Exploration Agency
  (JAXA), and previously flown aboard the FOXSI-3 sounding rocket. The
  detector consists of a 2k X 2k chip, 7 micron square pixel size, and
  rapid readout time enabling photon-counting capability. The science
  objective is to study small-scale, active region plasma flows associated
  with dynamic energy release. Within the constraints of a sounding
  rocket experiment, this will be accomplished via sub-arcsecond SXR
  observations of active region core plasma in a bandpass that overlaps
  with the temperature responses of Hinode/XRT and the SDO/AIA 94Å
  channel. The effective area curve of the mirror will be tuned via the
  mirror prescription and the multi-layer coating, which will shape the
  temperature response of the instrument. Here we present our science
  objectives and a technical overview of the instrument concept.

Title: Ghost-ray reduction and early results from the third FOXSI
    sounding rocket flight
Authors: Musset, Sophie; Buitrago-Casas, Juan Camilo; Glesener,
   Lindsay; Bongiorno, Stephen; Courtade, Sasha; Athiray, P. S.;
   Vievering, Juliana; Ishikawa, Shin-nosuke; Narukage, Noriyuki;
   Furukawa, Kento; Ryan, Daniel; Dalton, Greg; Turin, Zoe; Davis, Lance;
   Takahashi, Tadayuki; Watanabe, Shin; Mitsuishi, Ikuyuki; Hagino,
   Kouichi; Kawate, Tomoko; Turin, Paul; Christe, Steven; Ramsey, Brian;
   Krucker, Säm.
Bibcode: 2019SPIE11118E..12M
Altcode:
  The Focusing Optics X-ray Solar Imager (FOXSI) sounding rocket
  experiment demonstrates the technique of focusing hard X-ray (HXR)
  optics for the study of fundamental questions about the high-energy
  Sun. Solar HXRs provide one of the most direct diagnostics of
  accelerated electrons and the impulsive heating of the solar
  corona. Previous solar missions have been limited in sensitivity
  and dynamic range by the use of indirect imaging, but technological
  advances now make direct focusing accessible in the HXR regime, and the
  FOXSI rocket experiment optimizes HXR focusing telescopes for the unique
  scientific requirements of the Sun. FOXSI has completed three successful
  flights between 2012 and 2018. This paper gives a brief overview of
  the experiment, focusing on the third flight of the instrument on 2018
  Sept. 7. We present the telescope upgrades highlighting our work to
  understand and reduce the effects of singly reflected X-rays and show
  early science results obtained during FOXSI's third flight.

Title: The FOXSI-3 rocket: Overview and early results of its latest
    flight
Authors: Buitrago-Casas, Juan Camilo; Glesener, Lindsay; Courtade,
   Sasha; Vievering, Juliana; Athiray Panchapakesan, Subramania; Musset,
   Sophie; Ryan, Daniel; Dalton, Gregory; Ishikawa, Shin-Nosuke; Narukage,
   Noriyuki; Bongiorno, Stephen; Furukawa, Kento; Davis, Lance; Turin,
   Paul; Turin, Zoe; Takahashi, Tadayuki; Watanabe, Shin; Krucker, Sam;
   Christe, Steven; Ramsey, Brian
Bibcode: 2019AAS...23412602B
Altcode:
  Hard X-rays (HXRs) from the solar corona are closely connected to energy
  releases and particle transport in solar flares of all sizes. Expressly,
  faint solar HXR emissions are of remarkable interest in understanding
  solar flare structure and dynamics. This is because of their connection
  with, for instance, loop top emission and small flares. Mainly due to
  the indirect imaging methods used by past solar-dedicated HXR imagers,
  like RHESSI, faint HXRs observations have been limited by the imaging
  dynamic range and sensitivity of the instruments. <P />The Focusing
  Optics X-ray Solar Imager (FOXSI) sounding rocket payload is the first
  solar-dedicated instrument designed for performing imaging spectroscopy
  in the 4-20 keV range by using direct focusing optics. FOXSI has
  successfully flown three times from the White Sands Missile Range
  in New Mexico. For its latest rocket campaign (FOXSI-3), an enhanced
  version of the experiment, which includes optics and detector upgrades,
  was implemented for the launch which happened on September 7, 2018. In
  this talk, we present an overview of the FOXSI-3 campaign, describing
  in detail the improved capabilities of the telescope and how they
  allow for better investigation of faint coronal HXRs. We also present
  a preliminary analysis of the FOXSI-3 observations.

Title: FOXSI-2 Solar Microflares : Multi-Instrument Differential
    Emission Measure Analysis
Authors: Athiray, P. S.; Glesener, Lindsay; Vievering, Juliana;
   Ishikawa, Shin-Nosuke; Inglis, Andrew; Narukage, Noriyuki; Ryan,
   Daniel; Buitrago-Casas, Juan Camilo; Christe, Steven; Musset, Sophie;
   Krucker, Sam
Bibcode: 2019AAS...23422502A
Altcode:
  The plasma temperature distribution above 5 MK during microflares is
  often loosely constrained due to limited high sensitivity hard X-ray
  measurements covering the wide range of temperatures observed. The
  Focusing Optics X-ray Solar Imager (FOXSI) sounding rocket experiment
  performs direct imaging and spectroscopy of the Sun in hard X-rays,
  in the energy range 4 to 20 keV. FOXSI offers better sensitivity for
  temperatures above 5 MK by using direct focusing grazing incidence X-ray
  optics, the first of its kind for dedicated solar observations. The
  second FOXSI flight was launched on 2014 December 11 and observed
  microflares, quiescent Sun and quiescent active regions. This flight
  was coordinated with the X-ray Telescope (XRT) onboard Hinode and
  the Atmospheric Imaging Assembly (AIA) onboard SDO which offers
  unprecedented temperature coverage for characterizing the plasma
  temperature distribution. We present an overview of microflares
  observed during the FOXSI-2 flight with concurrent brightening
  observed in Extreme Ultraviolet (EUV) and soft X-rays, which indicates
  emission beyond 10 MK. By combining data from FOXSI-2, XRT, and AIA, we
  determined a well-constrained DEM for the microflares. The coordinated
  FOXSI-2 observations produce one of the few definitive measurements
  of the distribution and the amount of plasma above 5 MK in microflares.

Title: Satellite mission: PhoENiX (Physics of Energetic and
    Non-thermal plasmas in the X (= magnetic reconnection) region)
Authors: Narukage, Noriyuki
Bibcode: 2019AAS...23412603N
Altcode:
  We are studying a new solar satellite mission, "PhoENiX", for
  understanding of particle acceleration during magnetic reconnection,
  which are ubiquitous features exhibited by a wide range of plasmas
  in the universe. The main observation targets of this mission are
  solar flares that are caused by magnetic reconnection and accelerate
  plasma particles. The sun is a unique target in the sense that it
  can be investigated in great detail with good spatial, temporal and
  energy resolutions. The scientific objectives of this mission are (1)
  to identify particle acceleration sites, (2) to investigate temporal
  evolution of particle acceleration, and (3) to characterize properties
  of accelerated particles, during magnetic reconnection, i.e., during
  solar flares. In order to achieve these science objectives, the
  PhoENiX satellite is planned to be equipped with three instruments
  of (1) Photon-counting type focusing-imaging spectrometer in soft
  X-rays (up to 10 keV) demonstrated by FOXSI-3, (2) Photon-counting
  type focusing-imaging spectrometer in hard X-rays (up to 30 keV)
  like FOXSI series, and (3) Spectropolarimeter in soft gamma-rays
  (spectroscopy is available in the energy range of from &gt; 20 keV
  to &lt; 600 keV; spectropolarimetry is available from &gt; 60 keV
  to &lt; 600 keV) like Hitomi/SGD. We plan to realize this satellite
  mission around next solar maximum (around 2025). In this presentation,
  we will explain the details of science goal, science objectives and
  instruments of PhoENiX mission. Additionally, in order to demonstrate
  the unprecedented observations with PhoENiX, we will show the soft
  X-ray photon-counting data taken by FOXSI-3 sounding rocket.

Title: Modeling the Scattering Polarization of the Hydrogen Lyα
    Line Observed by CLASP in a Filament Channel
Authors: Štěpán, J.; Trujillo Bueno, J.; Gunár, S.; Heinzel, P.;
   del Pino Alemán, T.; Kano, R.; Ishikawa, R.; Narukage, N.; Bando,
   T.; Winebarger, A.; Kobayashi, K.; Auchère, F.
Bibcode: 2019ASPC..526..165S
Altcode:
  The 400 arcsec spectrograph slit of CLASP crossed mainly quiet
  regions of the solar chromosphere, from the limb towards the solar
  disk center. Interestingly, in the CLASP slit-jaw images and in the
  SDO images of the He II line at 304 Å, we can identify a filament
  channel (FC) extending over more than 60 arcsec crossing the slit of
  the spectrograph. In order to interpret the peculiar spatial variation
  of the Q/I and U/I signals observed by CLASP in the hydrogen Lyα line
  (1216 Å), we perform multi-dimensional radiative transfer modeling
  in given filament models. In this contribution, we show the first
  results of the two-dimensional calculations we have carried out, with
  the aim of determining the filament thermal and magnetic structure by
  comparing the theoretical and the observed polarization signals. Our
  results suggest that the temperature gradients in the filament observed
  by CLASP are significantly larger than previously thought.

Title: CLASP2: The Chromospheric LAyer Spectro-Polarimeter
Authors: McKenzie, D. E.; Ishikawa, R.; Trujillo Bueno, J.; Auchére,
   F.; Rachmeler, L. A.; Kubo, M.; Kobayashi, K.; Winebarger, A. R.;
   Bethge, C. W.; Narukage, N.; Kano, R.; Ishikawa, S.; de Pontieu,
   B.; Carlsson, M.; Yoshida, M.; Belluzzi, L.; Štěpán, J.; del Pino
   Alemán, T.; Alsina Ballester, E.; Asensio Ramos, A.
Bibcode: 2019ASPC..526..361M
Altcode:
  The hydrogen Lyman-α line at 121.6 nm and the Mg k line at 279.5
  nm are especially relevant for deciphering the magnetic structure
  of the chromosphere since their line-center signals are formed in
  the chromosphere and transition region, with unique sensitivities to
  magnetic fields. We propose the Chromospheric LAyer Spectro-Polarimeter
  (CLASP2), to build upon the success of the first CLASP flight, which
  measured the linear polarization in H I Lyman-α. The existing CLASP
  instrument will be refitted to measure all four Stokes parameters in
  the 280 nm range, including variations due to the anisotropic radiation
  pumping, the Hanle effect, and the Zeeman effect.

Title: Comparison of Scattering Polarization Signals Observed by
CLASP: Possible Indication of the Hanle Effect
Authors: Ishikawa, R.; Trujillo Bueno, J.; Uitenbroek, H.; Kubo, M.;
   Tsuneta, S.; Goto, M.; Kano, R.; Narukage, N.; Bando, T.; Katsukawa,
   Y.; Ishikawa, S.; Giono, G.; Suematsu, Y.; Hara, H.; Shimizu, T.;
   Sakao, T.; Winebarger, A.; Kobayashi, K.; Cirtain, J.; Champey, P.;
   Auchère, F.; Štěpán, J.; Belluzzi, L.; Asensio Ramos, A.; Manso
   Sainz, R.; De Pomtieu, B.; Ichimoto, K.; Carlsson, M.; Casini, R.
Bibcode: 2019ASPC..526..305I
Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP; Kano et
  al. 2012; Kobayashi et al. 2012; Kubo et al. 2014) observed, for the
  first time, the linear polarization produced by scattering processes
  in the hydrogen Lyman-α (121.57 nm) and Si III (120.56 nm) lines of
  the solar disk radiation. The complexity of the observed scattering
  polarization (i.e., conspicuous spatial variations in Q/I and U/I
  at spatial scales of 10″-20″ and the absence of center-to- limb
  variation at the Lyman-α center; see Kano et al. 2017) motivated us
  to search for possible hints of the operation of the Hanle effect by
  comparing: (a) the Lyman-α line center signal, for which the critical
  field strength (B<SUB>H</SUB>) for the onset of the Hanle effect is
  53 G, (b) the Lyman-α wing, which is insensitive to the Hanle effect,
  and (c) the Si III line, whose B<SUB>H</SUB> = 290 G. We focus on four
  regions with different total unsigned photospheric magnetic fluxes
  (estimated from SDO/HMI observations), and compare the corresponding
  U/I spatial variations in the Lyman-α wing, Lyman-α center, and Si III
  line. The U/I signal in the Lyman-α wing shows an antisymmetric spatial
  distribution, which is caused by the presence of a bright structure in
  all the selected regions, regardless of the total unsigned photospheric
  magnetic flux. In an internetwork region, the Lyman-α center shows an
  antisymmetric spatial variation across the selected bright structure,
  but it does not show it in other more magnetized regions. In the Si III
  line, the spatial variation of U/I deviates from the above-mentioned
  antisymmetric shape as the total unsigned photospheric magnetic flux
  increases. We argue that a plausible explanation of this differential
  behavior is the operation of the Hanle effect. <P />This work, presented
  in an oral contribution at this Workshop, has been published on The
  Astrophysical Journal (Ishikawa et al. 2017).

Title: High-speed X-ray imaging spectroscopy system with Zynq SoC
    for solar observations
Authors: Ishikawa, Shin-nosuke; Takahashi, Tadayuki; Watanabe,
   Shin; Narukage, Noriyuki; Miyazaki, Satoshi; Orita, Tadashi; Takeda,
   Shin'ichiro; Nomachi, Masaharu; Fujishiro, Iwao; Hodoshima, Fumio
Bibcode: 2018NIMPA.912..191I
Altcode: 2017arXiv171104372I
  We have developed a system combining a back-illuminated
  Complementary-Metal-Oxide-Semiconductor (CMOS) imaging sensor and
  Xilinx Zynq System-on-Chip (SoC) device for a soft X-ray (0.5-10 keV)
  imaging spectroscopy observation of the Sun to investigate the dynamics
  of the solar corona. Because typical timescales of energy release
  phenomena in the corona span a few minutes at most, we aim to obtain
  the corresponding energy spectra and derive the physical parameters,
  i.e., temperature and emission measure, every few tens of seconds
  or less for future solar X-ray observations. An X-ray photon-counting
  technique, with a frame rate of a few hundred frames per second or more,
  can achieve such results. We used the Zynq SoC device to achieve the
  requirements. Zynq contains an ARM processor core, which is also known
  as the Processing System (PS) part, and a Programable Logic (PL) part in
  a single chip. We use the PL and PS to control the sensor and seamless
  recording of data to a storage system, respectively. We aim to use the
  system for the third flight of the Focusing Optics Solar X-ray Imager
  (FOXSI-3) sounding rocket experiment for the first photon-counting
  X-ray imaging and spectroscopy of the Sun.

Title: CLASP Constraints on the Magnetization and Geometrical
    Complexity of the Chromosphere-Corona Transition Region
Authors: Trujillo Bueno, J.; Štěpán, J.; Belluzzi, L.; Asensio
   Ramos, A.; Manso Sainz, R.; del Pino Alemán, T.; Casini, R.; Ishikawa,
   R.; Kano, R.; Winebarger, A.; Auchère, F.; Narukage, N.; Kobayashi,
   K.; Bando, T.; Katsukawa, Y.; Kubo, M.; Ishikawa, S.; Giono, G.; Hara,
   H.; Suematsu, Y.; Shimizu, T.; Sakao, T.; Tsuneta, S.; Ichimoto, K.;
   Cirtain, J.; Champey, P.; De Pontieu, B.; Carlsson, M.
Bibcode: 2018ApJ...866L..15T
Altcode: 2018arXiv180908865T
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a
  suborbital rocket experiment that on 2015 September 3 measured
  the linear polarization produced by scattering processes in the
  hydrogen Lyα line of the solar disk radiation. The line-center
  photons of this spectral line radiation mostly stem from the
  chromosphere-corona transition region (TR). These unprecedented
  spectropolarimetric observations revealed an interesting surprise,
  namely that there is practically no center-to-limb variation (CLV) in
  the Q/I line-center signals. Using an analytical model, we first show
  that the geometric complexity of the corrugated surface that delineates
  the TR has a crucial impact on the CLV of the Q/I and U/I line-center
  signals. Second, we introduce a statistical description of the solar
  atmosphere based on a 3D model derived from a state-of-the-art radiation
  magnetohydrodynamic simulation. Each realization of the statistical
  ensemble is a 3D model characterized by a given degree of magnetization
  and corrugation of the TR, and for each such realization we solve the
  full 3D radiative transfer problem taking into account the impact
  of the CLASP instrument degradation on the calculated polarization
  signals. Finally, we apply the statistical inference method presented
  in a previous paper to show that the TR of the 3D model that produces
  the best agreement with the CLASP observations has a relatively weak
  magnetic field and a relatively high degree of corrugation. We emphasize
  that a suitable way to validate or refute numerical models of the upper
  solar chromosphere is by confronting calculations and observations
  of the scattering polarization in ultraviolet lines sensitive to the
  Hanle effect.

Title: A Statistical Inference Method for Interpreting the CLASP
    Observations
Authors: Štěpán, J.; Trujillo Bueno, J.; Belluzzi, L.; Asensio
   Ramos, A.; Manso Sainz, R.; del Pino Alemán, T.; Casini, R.; Kano, R.;
   Winebarger, A.; Auchère, F.; Ishikawa, R.; Narukage, N.; Kobayashi,
   K.; Bando, T.; Katsukawa, Y.; Kubo, M.; Ishikawa, S.; Giono, G.; Hara,
   H.; Suematsu, Y.; Shimizu, T.; Sakao, T.; Tsuneta, S.; Ichimoto, K.;
   Cirtain, J.; Champey, P.; De Pontieu, B.; Carlsson, M.
Bibcode: 2018ApJ...865...48S
Altcode: 2018arXiv180802725S
  On 2015 September 3, the Chromospheric Lyman-Alpha SpectroPolarimeter
  (CLASP) successfully measured the linear polarization produced by
  scattering processes in the hydrogen Lyα line of the solar disk
  radiation, revealing conspicuous spatial variations in the Q/I and U/I
  signals. Via the Hanle effect, the line-center Q/I and U/I amplitudes
  encode information on the magnetic field of the chromosphere-corona
  transition region, but they are also sensitive to the three-dimensional
  structure of this corrugated interface region. With the help of a simple
  line-formation model, here we propose a statistical inference method
  for interpreting the Lyα line-center polarization observed by CLASP.

Title: Current State of UV Spectro-Polarimetry and its Future
    Direction
Authors: Ishikawa, Ryohko; Sakao, Taro; Katsukawa, Yukio; Hara,
   Hirohisa; Ichimoto, Kiyoshi; Shimizu, Toshifumi; Kubo, Masahito;
   Auchere, Frederic; De Pontieu, Bart; Winebarger, Amy; Kobayashi,
   . Ken; Kano, Ryouhei; Narukage, Noriyuki; Trujillo Bueno, Javier;
   Song, Dong-uk; Manso Sainz, Rafael; Asensio Ramos, Andres; Leenaarts,
   Jorritt; Carlsson, Mats; Bando, Takamasa; Ishikawa, Shin-nosuke;
   Tsuneta, Saku; Belluzzi, Luca; Suematsu, Yoshinori; Giono, Gabriel;
   Yoshida, Masaki; Goto, Motoshi; Del Pino Aleman, Tanausu; Stepan,
   Jiri; Okamoto, Joten; Tsuzuki, Toshihiro; Uraguchi, Fumihiro; Champey,
   Patrick; Alsina Ballester, Ernest; Casini, Roberto; McKenzie, David;
   Rachmeler, Laurel; Bethge, Christian
Bibcode: 2018cosp...42E1564I
Altcode:
  To obtain quantitative information on the magnetic field in low beta
  regions (i.e., upper chromosphere and above) has been increasingly
  important to understand the energetic phenomena of the outer
  solar atmosphere such as flare, coronal heating, and the solar wind
  acceleration. In the UV range, there are abundant spectral lines that
  originate in the upper chromosphere and transition region. However,
  the Zeeman effect in these spectral lines does not give rise to easily
  measurable polarization signals because of the weak magnetic field
  strength and the larger Doppler broadening compared with the Zeeman
  effect. Instead, the Hanle effect in UV lines is expected to be a
  suitable diagnostic tool of the magnetic field in the upper atmospheric
  layers. To investigate the validity of UV spectro-polarimetry and
  the Hanle effect, the Chromospheric Lyman-Alpha Spectro-Polarimeter
  (CLASP), which is a NASA sounding- rocket experiment, was launched at
  White Sands in US on September 3, 2015. During its 5 minutes ballistic
  flight, it successfully performed spectro-polarimetric observations
  of the hydrogen Lyman-alpha line (121.57 nm) with an unprecedentedly
  high polarization sensitivity of 0.1% in this wavelength range. CLASP
  observed the linear polarization produced by scattering process in VUV
  lines for the first time and detected the polarization signals which
  indicate the operation of the Hanle effect. Following the success
  of CLASP, we are confident that UV spectro-polarimetry is the way
  to proceed, and we are planning the second flight of CLASP (CLASP2:
  Chromospheric LAyer SpectroPolarimeter 2). For this second flight we
  will carry out spectro-polarimetry in the Mg II h and k lines around
  280 nm, with minimum modifications of the CLASP1 instrument. The linear
  polarization in the Mg II k line is induced by scattering processes and
  the Hanle effect, being sensitive to magnetic field strengths of 5 to 50
  G. In addition, the circular polarizations in the Mg II h and k lines
  induced by the Zeeman effect can be measurable in at least plage and
  active regions. The combination of the Hanle and Zeeman effects could
  help us to more reliably infer the magnetic fields of the upper solar
  chromosphere. CLASP2 was selected for flight and is being developed for
  launch in the spring of 2019.Based on these sounding rocket experiments
  (CLASP1 and 2), we aim at establishing the strategy and refining the
  instrument concept for future space missions to explore the enigmatic
  atmospheric layers via UV spectro-polarimetry.

Title: Wavefront error measurements and alignment of CLASP2 telescope
    with a dual-band pass cold mirror coated primary mirror
Authors: Yoshida, Masaki; Song, Donguk; Ishikawa, Ryoko; Kano, Ryouhei;
   Katsukawa, Yukio; Suematsu, Yoshinori; Narukage, Noriyuki; Kubo,
   Masahito; Shinoda, Kazuya; Okamoto, Takenori J.; McKenzie, David E.;
   Rachmeler, Laurel A.; Auchère, Frédéric; Trujillo Bueno, Javier
Bibcode: 2018SPIE10699E..30Y
Altcode:
  "Chromospheric LAyer Spectro-Polarimeter (CLASP2)" is the next sounding
  rocket experiment of the "Chromospheric Lyman-Alpha Spectro-Polarimeter
  (CLASP)" that succeeded in observing for the first time the linear
  polarization spectra in the hydrogen Lyman-α line (121.6 nm) and is
  scheduled to be launched in 2019. In CLASP2, we will carry out full
  Stokes-vector spectropolarimetric observations in the Mg ii h and k
  lines near 280 nm with the spectro-polarimeter (SP), while imaging
  observations in the Lyman-α line will be conducted with the slitjaw
  optics (SJ). For the wavelength selection of CLASP2, the primary
  mirror of the telescope uses a new dual-band pass cold mirror coating
  targeting both at 121.6 nm and 280 nm. Therefore, we have to perform
  again the alignment of the telescope after the installation of the
  recoated primary mirror. Before unmounting the primary mirror from
  the telescope structure, we measured the wave-front error (WFE) of the
  telescope. The measured WFE map was consistent with what we had before
  the CLASP flight, clearly indicating that the telescope alignment has
  been maintained even after the flight. After the re-coated primary
  mirror was installed the WFE was measured, and coma aberration was
  found to be larger. Finally, the secondary mirror shim adjustments
  were carried out based on the WFE measurements. In CLASP2 telescope,
  we improved a fitting method of WFE map (applying 8th terms circular
  Zernike polynomial fitting instead of 37th terms circular Zernike
  fitting) and the improved method enables to achieve better performance
  than CLASP telescope. Indeed, WFE map obtained after the final shim
  adjustment indicated that the required specification (&lt; 5.5 μm
  RMS spot radius) that is more stringent than CLASP telescope was met.

Title: Detection of nanoflare-heated plasma in the solar corona by
    the FOXSI-2 sounding rocket
Authors: Ishikawa, Shin-nosuke; Glesener, Lindsay; Krucker, Säm;
   Christe, Steven; Buitrago-Casas, Juan Camilo; Narukage, Noriyuki;
   Vievering, Juliana
Bibcode: 2017NatAs...1..771I
Altcode:
  The processes that heat the solar and stellar coronae to several million
  kelvins, compared with the much cooler photosphere (5,800 K for the
  Sun), are still not well known<SUP>1</SUP>. One proposed mechanism
  is heating via a large number of small, unresolved, impulsive heating
  events called nanoflares<SUP>2</SUP>. Each event would heat and cool
  quickly, and the average effect would be a broad range of temperatures
  including a small amount of extremely hot plasma. However, detecting
  these faint, hot traces in the presence of brighter, cooler emission
  is observationally challenging. Here we present hard X-ray data from
  the second flight of the Focusing Optics X-ray Solar Imager (FOXSI-2),
  which detected emission above 7 keV from an active region of the Sun
  with no obvious individual X-ray flare emission. Through differential
  emission measure computations, we ascribe this emission to plasma
  heated above 10 MK, providing evidence for the existence of solar
  nanoflares. The quantitative evaluation of the hot plasma strongly
  constrains the coronal heating models.

Title: Comparison of Solar Fine Structure Observed Simultaneously
    in Lyα and Mg II h
Authors: Schmit, D.; Sukhorukov, A. V.; De Pontieu, B.; Leenaarts,
   J.; Bethge, C.; Winebarger, A.; Auchère, F.; Bando, T.; Ishikawa,
   R.; Kano, R.; Kobayashi, K.; Narukage, N.; Trujillo Bueno, J.
Bibcode: 2017ApJ...847..141S
Altcode: 2017arXiv170900035S
  The Chromospheric Lyman Alpha Spectropolarimeter (CLASP) observed the
  Sun in H I Lyα during a suborbital rocket flight on 2015 September
  3. The Interface Region Imaging Telescope (IRIS) coordinated with the
  CLASP observations and recorded nearly simultaneous and co-spatial
  observations in the Mg II h and k lines. The Mg II h and Lyα lines
  are important transitions, energetically and diagnostically, in the
  chromosphere. The canonical solar atmosphere model predicts that these
  lines form in close proximity to each other and so we expect that the
  line profiles will exhibit similar variability. In this analysis, we
  present these coordinated observations and discuss how the two profiles
  compare over a region of quiet Sun at viewing angles that approach the
  limb. In addition to the observations, we synthesize both line profiles
  using a 3D radiation-MHD simulation. In the observations, we find that
  the peak width and the peak intensities are well correlated between the
  lines. For the simulation, we do not find the same relationship. We
  have attempted to mitigate the instrumental differences between IRIS
  and CLASP and to reproduce the instrumental factors in the synthetic
  profiles. The model indicates that formation heights of the lines
  differ in a somewhat regular fashion related to magnetic geometry. This
  variation explains to some degree the lack of correlation, observed
  and synthesized, between Mg II and Lyα. Our analysis will aid in the
  definition of future observatories that aim to link dynamics in the
  chromosphere and transition region.

Title: CLASP/SJ Observations of Rapid Time Variations in the Lyα
    Emission in a Solar Active Region
Authors: Ishikawa, Shin-nosuke; Kubo, Masahito; Katsukawa, Yukio;
   Kano, Ryouhei; Narukage, Noriyuki; Ishikawa, Ryohko; Bando, Takamasa;
   Winebarger, Amy; Kobayashi, Ken; Trujillo Bueno, Javier; Auchère,
   Frédéric
Bibcode: 2017ApJ...846..127I
Altcode:
  The Chromospheric Lyα SpectroPolarimeter (CLASP) is a sounding
  rocket experiment launched on 2015 September 3 to investigate the
  solar chromosphere and transition region. The slit-jaw (SJ) optical
  system captured Lyα images with a high time cadence of 0.6 s. From
  the CLASP/SJ observations, many variations in the solar chromosphere
  and transition region emission with a timescale of &lt;1 minute
  were discovered. In this paper, we focus on the active region within
  the SJ field of view and investigate the relationship between short
  (&lt;30 s) temporal variations in the Lyα emission and the coronal
  structures observed by Solar Dynamics Observatory/Atmospheric Imaging
  Assembly (AIA). We compare the Lyα temporal variations at the coronal
  loop footpoints observed in the AIA 211 Å (≈2 MK) and AIA 171 Å
  (≈0.6 MK) channels with those in the regions with bright Lyα features
  without a clear association with the coronal loop footpoints. We find
  more short (&lt;30 s) temporal variations in the Lyα intensity in the
  footpoint regions. Those variations did not depend on the temperature
  of the coronal loops. Therefore, the temporal variations in the Lyα
  intensity at this timescale range could be related to the heating of
  the coronal structures up to temperatures around the sensitivity peak
  of 171 Å. No signature was found to support the scenario that these
  Lyα intensity variations were related to the nanoflares. Waves or
  jets from the lower layers (lower chromosphere or photosphere) are
  possible causes for this phenomenon.

Title: Methods for reducing singly reflected rays on the Wolter-I
    focusing mirrors of the FOXSI rocket experiment
Authors: Buitrago-Casas, Juan Camilo; Elsner, Ronald; Glesener,
   Lindsay; Christe, Steven; Ramsey, Brian; Courtade, Sasha; Ishikawa,
   Shin-nosuke; Narukage, Noriyuki; Turin, Paul; Vievering, Juliana;
   Athiray, P. S.; Musset, Sophie; Krucker, Säm.
Bibcode: 2017SPIE10399E..0JB
Altcode:
  In high energy solar astrophysics, imaging hard X-rays by direct
  focusing offers higher dynamic range and greater sensitivity compared to
  past techniques that used indirect imaging. The Focusing Optics X-ray
  Solar Imager (FOXSI) is a sounding rocket payload that uses seven sets
  of nested Wolter-I figured mirrors together with seven high-sensitivity
  semiconductor detectors to observe the Sun in hard X-rays through direct
  focusing. The FOXSI rocket has successfully flown twice and is funded
  to fly a third time in summer 2018. The Wolter-I geometry consists
  of two consecutive mirrors, one paraboloid and one hyperboloid, that
  reflect photons at grazing angles. Correctly focused X-rays reflect
  once per mirror segment. For extended sources, like the Sun, off-axis
  photons at certain incident angles can reflect on only one mirror and
  still reach the focal plane, generating a background pattern of singly
  reflected rays (i.e., ghost rays) that can limit the sensitivity of the
  observation to faint, focused sources. Understanding and mitigating
  the impact of the singly reflected rays on the FOXSI optical modules
  will maximize the instruments' sensitivity to background-limited
  sources. We present an analysis of the FOXSI singly reflected rays
  based on ray-tracing simulations and laboratory measurements, as well
  as the effectiveness of different physical strategies to reduce them.

Title: Detection of Heating Processes in Coronal Loops by Soft
    X-ray Spectroscopy
Authors: Kawate, Tomoko; Narukage, Noriyuki; Ishikawa, Shin-nosuke;
   Imada, Shinsuke
Bibcode: 2017SPD....4810615K
Altcode:
  Imaging and Spectroscopic observations in the soft X-ray band will open
  a new window of the heating/acceleration/transport processes in the
  solar corona. The soft X-ray spectrum between 0.5 and 10 keV consists
  of the electron thermal free-free continuum and hot coronal lines such
  as O VIII, Fe XVII, Mg XI, Si XVII. Intensity of free-free continuum
  emission is not affected by the population of ions, whereas line
  intensities especially from highly ionized species have a sensitivity of
  the timescale of ionization/recombination processes. Thus, spectroscopic
  observations of both continuum and line intensities have a capability of
  diagnostics of heating/cooling timescales. We perform a 1D hydrodynamic
  simulation coupled with the time-dependent ionization, and calculate
  continuum and line intensities under different heat input conditions
  in a coronal loop. We also examine the differential emission measure
  of the coronal loop from the time-integrated soft x-ray spectra. As a
  result, line intensity shows a departure from the ionization equilibrium
  and shows different responses depending on the frequency of the heat
  input. Solar soft X-ray spectroscopic imager will be mounted in the
  sounding rocket experiment of the Focusing Optics X-ray Solar Imager
  (FOXSI). This observation will deepen our understanding of heating
  processes to solve the “coronal heating problem”.

Title: CLASP2: The Chromospheric LAyer Spectro-Polarimeter
Authors: Rachmeler, Laurel; E McKenzie, David; Ishikawa, Ryohko;
   Trujillo Bueno, Javier; Auchère, Frédéric; Kobayashi, Ken;
   Winebarger, Amy; Bethge, Christian; Kano, Ryouhei; Kubo, Masahito;
   Song, Donguk; Narukage, Noriyuki; Ishikawa, Shin-nosuke; De Pontieu,
   Bart; Carlsson, Mats; Yoshida, Masaki; Belluzzi, Luca; Stepan, Jiri;
   del Pino Alemná, Tanausú; Ballester, Ernest Alsina; Asensio Ramos,
   Andres
Bibcode: 2017SPD....4811010R
Altcode:
  We present the instrument, science case, and timeline of the CLASP2
  sounding rocket mission. The successful CLASP (Chromospheric Lyman-Alpha
  Spectro-Polarimeter) sounding rocket flight in 2015 resulted in
  the first-ever linear polarization measurements of solar hydrogen
  Lyman-alpha line, which is sensitive to the Hanle effect and can be used
  to constrain the magnetic field and geometric complexity of the upper
  chromosphere. Ly-alpha is one of several upper chromospheric lines that
  contain magnetic information. In the spring of 2019, we will re-fly
  the modified CLASP telescope to measure the full Stokes profile of Mg
  II h &amp; k near 280 nm. This set of lines is sensitive to the upper
  chromospheric magnetic field via both the Hanle and the Zeeman effects.

Title: CLASP2: The Chromospheric LAyer Spectro-Polarimeter
Authors: Rachmeler, Laurel A.; McKenzie, D. E.; Ishikawa, R.;
   Trujillo-Bueno, J.; Auchere, F.; Kobayashi, K.; Winebarger, A.;
   Bethge, C.; Kano, R.; Kubo, M.; Song, D.; Narukage, N.; Ishikawa, S.;
   De Pontieu, B.; Carlsson, M.; Yoshida, M.; Belluzzi, L.; Stepan, J.;
   del Pino Alemán, T.; Alsina Ballester, E.; Asensio Ramos, A.
Bibcode: 2017shin.confE..79R
Altcode:
  We present the instrument, science case, and timeline of the CLASP2
  sounding rocket mission. The successful CLASP (Chromospheric Lyman-Alpha
  Spectro-Polarimeter) sounding rocket flight in 2015 resulted in
  the first-ever linear polarization measurements of solar hydrogen
  Lyman-alpha line, which is sensitive to the Hanle effect and can be used
  to constrain the magnetic field and geometric complexity of the upper
  chromosphere. Ly-alpha is one of several upper chromospheric lines that
  contain magnetic information. In the spring of 2019, we will re-fly
  the modified CLASP telescope to measure the full Stokes profile of Mg
  II h &amp; k near 280 nm. This set of lines is sensitive to the upper
  chromospheric magnetic field via both the Hanle and the Zeeman effects.

Title: White paper of the "soft X-ray imaging spectroscopy"
Authors: Narukage, Noriyuki; Ishikawa, Shin-nosuke; Kawate, Tomoko;
   Imada, Shinsuke; Sakao, Taro
Bibcode: 2017arXiv170604536N
Altcode:
  The solar corona is full of dynamic phenomena, e.g., solar flares,
  micro flares in active regions, jets in coronal holes and in the polar
  regions, X-ray bright points in quiet regions, etc. They are accompanied
  by interesting physical processes, namely, magnetic reconnection,
  particle acceleration, shocks, waves, flows, evaporation, heating,
  cooling, and so on. The understandings of these phenomena and processes
  have been progressing step-by-step with the evolution of the observation
  technology in EUV and X-rays from the space. But, there are fundamental
  questions remain unanswered, or haven't even addressed so far. Our
  scientific objective is to understand underlying physics of dynamic
  phenomena in the solar corona, covering some of the long-standing
  questions in solar physics such as particle acceleration in flares
  and coronal heating. In order to achieve these science objectives,
  we identify the imaging spectroscopy (the observations with spatial,
  temporal and energy resolutions) in the soft X-ray range (from ~0.5
  keV to ~10 keV) is a powerful approach for the detection and analysis
  of energetic events.

Title: Indication of the Hanle Effect by Comparing the Scattering
    Polarization Observed by CLASP in the Lyα and Si III 120.65 nm Lines
Authors: Ishikawa, R.; Trujillo Bueno, J.; Uitenbroek, H.; Kubo, M.;
   Tsuneta, S.; Goto, M.; Kano, R.; Narukage, N.; Bando, T.; Katsukawa,
   Y.; Ishikawa, S.; Giono, G.; Suematsu, Y.; Hara, H.; Shimizu, T.;
   Sakao, T.; Winebarger, A.; Kobayashi, K.; Cirtain, J.; Champey, P.;
   Auchère, F.; Štěpán, J.; Belluzzi, L.; Asensio Ramos, A.; Manso
   Sainz, R.; De Pontieu, B.; Ichimoto, K.; Carlsson, M.; Casini, R.
Bibcode: 2017ApJ...841...31I
Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter is a sounding
  rocket experiment that has provided the first successful measurement
  of the linear polarization produced by scattering processes in
  the hydrogen Lyα line (121.57 nm) radiation of the solar disk. In
  this paper, we report that the Si III line at 120.65 nm also shows
  scattering polarization and we compare the scattering polarization
  signals observed in the Lyα and Si III lines in order to search for
  observational signatures of the Hanle effect. We focus on four selected
  bright structures and investigate how the U/I spatial variations vary
  between the Lyα wing, the Lyα core, and the Si III line as a function
  of the total unsigned photospheric magnetic flux estimated from Solar
  Dynamics Observatory/Helioseismic and Magnetic Imager observations. In
  an internetwork region, the Lyα core shows an antisymmetric spatial
  variation across the selected bright structure, but it does not show
  it in other more magnetized regions. In the Si III line, the spatial
  variation of U/I deviates from the above-mentioned antisymmetric
  shape as the total unsigned photospheric magnetic flux increases. A
  plausible explanation of this difference is the operation of the Hanle
  effect. We argue that diagnostic techniques based on the scattering
  polarization observed simultaneously in two spectral lines with very
  different sensitivities to the Hanle effect, like Lyα and Si III,
  are of great potential interest for exploring the magnetism of the
  upper solar chromosphere and transition region.

Title: Polarization Calibration of the Chromospheric Lyman-Alpha
    SpectroPolarimeter for a 0.1% Polarization Sensitivity in the VUV
Range. Part II: In-Flight Calibration
Authors: Giono, G.; Ishikawa, R.; Narukage, N.; Kano, R.; Katsukawa,
   Y.; Kubo, M.; Ishikawa, S.; Bando, T.; Hara, H.; Suematsu, Y.;
   Winebarger, A.; Kobayashi, K.; Auchère, F.; Trujillo Bueno, J.;
   Tsuneta, S.; Shimizu, T.; Sakao, T.; Cirtain, J.; Champey, P.; Asensio
   Ramos, A.; Štěpán, J.; Belluzzi, L.; Manso Sainz, R.; De Pontieu,
   B.; Ichimoto, K.; Carlsson, M.; Casini, R.; Goto, M.
Bibcode: 2017SoPh..292...57G
Altcode:
  The Chromospheric Lyman-Alpha SpectroPolarimeter is a sounding
  rocket instrument designed to measure for the first time the linear
  polarization of the hydrogen Lyman-α line (121.6 nm). The instrument
  was successfully launched on 3 September 2015 and observations were
  conducted at the solar disc center and close to the limb during the
  five-minutes flight. In this article, the disc center observations are
  used to provide an in-flight calibration of the instrument spurious
  polarization. The derived in-flight spurious polarization is consistent
  with the spurious polarization levels determined during the pre-flight
  calibration and a statistical analysis of the polarization fluctuations
  from solar origin is conducted to ensure a 0.014% precision on the
  spurious polarization. The combination of the pre-flight and the
  in-flight polarization calibrations provides a complete picture of
  the instrument response matrix, and a proper error transfer method
  is used to confirm the achieved polarization accuracy. As a result,
  the unprecedented 0.1% polarization accuracy of the instrument in the
  vacuum ultraviolet is ensured by the polarization calibration.

Title: Discovery of Scattering Polarization in the Hydrogen Lyα
    Line of the Solar Disk Radiation
Authors: Kano, R.; Trujillo Bueno, J.; Winebarger, A.; Auchère, F.;
   Narukage, N.; Ishikawa, R.; Kobayashi, K.; Bando, T.; Katsukawa, Y.;
   Kubo, M.; Ishikawa, S.; Giono, G.; Hara, H.; Suematsu, Y.; Shimizu,
   T.; Sakao, T.; Tsuneta, S.; Ichimoto, K.; Goto, M.; Belluzzi, L.;
   Štěpán, J.; Asensio Ramos, A.; Manso Sainz, R.; Champey, P.;
   Cirtain, J.; De Pontieu, B.; Casini, R.; Carlsson, M.
Bibcode: 2017ApJ...839L..10K
Altcode: 2017arXiv170403228K
  There is a thin transition region (TR) in the solar atmosphere where
  the temperature rises from 10,000 K in the chromosphere to millions
  of degrees in the corona. Little is known about the mechanisms that
  dominate this enigmatic region other than the magnetic field plays a
  key role. The magnetism of the TR can only be detected by polarimetric
  measurements of a few ultraviolet (UV) spectral lines, the Lyα line
  of neutral hydrogen at 121.6 nm (the strongest line of the solar UV
  spectrum) being of particular interest given its sensitivity to the
  Hanle effect (the magnetic-field-induced modification of the scattering
  line polarization). We report the discovery of linear polarization
  produced by scattering processes in the Lyα line, obtained with
  the Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) rocket
  experiment. The Stokes profiles observed by CLASP in quiet regions of
  the solar disk show that the Q/I and U/I linear polarization signals are
  of the order of 0.1% in the line core and up to a few percent in the
  nearby wings, and that both have conspicuous spatial variations with
  scales of ∼10 arcsec. These observations help constrain theoretical
  models of the chromosphere-corona TR and extrapolations of the
  magnetic field from photospheric magnetograms. In fact, the observed
  spatial variation from disk to limb of polarization at the line core
  and wings already challenge the predictions from three-dimensional
  magnetohydrodynamical models of the upper solar chromosphere.

Title: High-Reflectivity Coatings for a Vacuum Ultraviolet
    Spectropolarimeter
Authors: Narukage, Noriyuki; Kubo, Masahito; Ishikawa, Ryohko;
   Ishikawa, Shin-nosuke; Katsukawa, Yukio; Kobiki, Toshihiko; Giono,
   Gabriel; Kano, Ryouhei; Bando, Takamasa; Tsuneta, Saku; Auchère,
   Frédéric; Kobayashi, Ken; Winebarger, Amy; McCandless, Jim; Chen,
   Jianrong; Choi, Joanne
Bibcode: 2017SoPh..292...40N
Altcode:
  Precise polarization measurements in the vacuum ultraviolet (VUV)
  region are expected to be a new tool for inferring the magnetic fields
  in the upper atmosphere of the Sun. High-reflectivity coatings are key
  elements to achieving high-throughput optics for precise polarization
  measurements. We fabricated three types of high-reflectivity coatings
  for a solar spectropolarimeter in the hydrogen Lyman-α (Lyα ; 121.567
  nm) region and evaluated their performance. The first high-reflectivity
  mirror coating offers a reflectivity of more than 80 % in Lyα
  optics. The second is a reflective narrow-band filter coating that has
  a peak reflectivity of 57 % in Lyα , whereas its reflectivity in the
  visible light range is lower than 1/10 of the peak reflectivity (∼5
  % on average). This coating can be used to easily realize a visible
  light rejection system, which is indispensable for a solar telescope,
  while maintaining high throughput in the Lyα line. The third is a
  high-efficiency reflective polarizing coating that almost exclusively
  reflects an s-polarized beam at its Brewster angle of 68° with a
  reflectivity of 55 %. This coating achieves both high polarizing power
  and high throughput. These coatings contributed to the high-throughput
  solar VUV spectropolarimeter called the Chromospheric Lyman-Alpha
  SpectroPolarimeter (CLASP), which was launched on 3 September, 2015.

Title: Polarization Calibration of the Chromospheric Lyman-Alpha
    SpectroPolarimeter for a 0.1 % Polarization Sensitivity in the VUV
Range. Part I: Pre-flight Calibration
Authors: Giono, G.; Ishikawa, R.; Narukage, N.; Kano, R.; Katsukawa,
   Y.; Kubo, M.; Ishikawa, S.; Bando, T.; Hara, H.; Suematsu, Y.;
   Winebarger, A.; Kobayashi, K.; Auchère, F.; Trujillo Bueno, J.
Bibcode: 2016SoPh..291.3831G
Altcode: 2016SoPh..tmp..177G
  The Chromospheric Lyman-Alpha SpectroPolarimeter (CLASP) is a sounding
  rocket experiment designed to measure for the first time the linear
  polarization of the hydrogen Lyman-α line (121.6 nm) and requires
  a 0.1 % polarization sensitivity, which is unprecedented for a
  spectropolarimeter in the vacuum UV (VUV) spectral range.

Title: Creation of Super-Hot Plasmas in a Flux Eruption Event as
    seen in Soft X-rays with Hinode/XRT
Authors: Sakao, T.; Shimojo, M.; Narukage, N.
Bibcode: 2016AGUFMSH11D..04S
Altcode:
  The X-Ray Telescope (XRT) aboard Hinode observes soft X-ray emission
  from the solar corona with its energy range 0.06 - 2 keV and is capable
  of imaging, and diagnosing, a wide range of coronal temperatures
  from below 1 MK to beyond 20 MK, without gaps in the temperature
  coverage. In particular, the grazing-incidence nature of the XRT
  optics is suited for imaging high-temperature plasmas (&gt;20 MK)
  created during the course of flares that are not necessarily well
  accessible with coronal imagers utilizing EUV emission lines. We
  report XRT observations of an eruptive flare (GOES M1.1) that took
  place behind the east limb at 18:30 UT on 14 October 2014. X-ray
  images traced a flux eruption which corresponds to the early stage of
  a CME observed with SoHO/LASCO, with a flux-rope-like feature ejected
  as the flare progressed. Filter-ratio temperatures of the soft X-ray
  flaring structure derived from multiple-filter observation of the flare
  suggest possible creation of super-hot (reaching as high as 30 MK)
  plasmas that distributed from near the apex of the erupting structure
  (where the flux rope was present), downwards along the sides of the
  structure. The observation may be the first identification in images of
  super-hot plasmas in the soft X-ray range, covering up to 2 keV. XRT
  observations on the creation of super-hot plasmas during the course
  of the flux eruption will be reported and its implication discussed.

Title: Discovery of Ubiquitous Fast-Propagating Intensity Disturbances
    by the Chromospheric Lyman Alpha Spectropolarimeter (CLASP)
Authors: Kubo, M.; Katsukawa, Y.; Suematsu, Y.; Kano, R.; Bando,
   T.; Narukage, N.; Ishikawa, R.; Hara, H.; Giono, G.; Tsuneta, S.;
   Ishikawa, S.; Shimizu, T.; Sakao, T.; Winebarger, A.; Kobayashi, K.;
   Cirtain, J.; Champey, P.; Auchère, F.; Trujillo Bueno, J.; Asensio
   Ramos, A.; Štěpán, J.; Belluzzi, L.; Manso Sainz, R.; De Pontieu,
   B.; Ichimoto, K.; Carlsson, M.; Casini, R.; Goto, M.
Bibcode: 2016ApJ...832..141K
Altcode:
  High-cadence observations by the slit-jaw (SJ) optics system of the
  sounding rocket experiment known as the Chromospheric Lyman Alpha
  Spectropolarimeter (CLASP) reveal ubiquitous intensity disturbances
  that recurrently propagate in either the chromosphere or the transition
  region or both at a speed much higher than the speed of sound. The
  CLASP/SJ instrument provides a time series of two-dimensional images
  taken with broadband filters centered on the Lyα line at a 0.6 s
  cadence. The multiple fast-propagating intensity disturbances appear in
  the quiet Sun and in an active region, and they are clearly detected in
  at least 20 areas in a field of view of 527″ × 527″ during the 5
  minute observing time. The apparent speeds of the intensity disturbances
  range from 150 to 350 km s<SUP>-1</SUP>, and they are comparable
  to the local Alfvén speed in the transition region. The intensity
  disturbances tend to propagate along bright elongated structures away
  from areas with strong photospheric magnetic fields. This suggests
  that the observed fast-propagating intensity disturbances are related
  to the magnetic canopy structures. The maximum distance traveled by
  the intensity disturbances is about 10″, and the widths are a few
  arcseconds, which are almost determined by a pixel size of 1.″03. The
  timescale of each intensity pulse is shorter than 30 s. One possible
  explanation for the fast-propagating intensity disturbances observed
  by CLASP is magnetohydrodynamic fast-mode waves.

Title: Quiet-sun and non-flaring active region measurements from
    the FOXSI-2 sounding rocket
Authors: Buitrago-Casas, J. C.; Glesener, L.; Christe, S.; Ishikawa,
   S. N.; Narukage, N.; Krucker, S.; Bale, S. D.
Bibcode: 2016AGUFMSH13A2280B
Altcode:
  Solar hard X-ray (HXR) emissions are a cornerstone for understanding
  particle acceleration and energy release in the corona. These
  phenomena are present at different size scales and intensities, from
  large eruptive events down to the smallest flares. The presence of
  HXRs in small, unresolved flares would provide direct evidence of
  small reconnection events, i.e. nano-flares, that are thought to
  be be important for the unsolved coronal heating problem. Currently
  operating solar-dedicated instruments that observe HXRs from the Sun
  do not have the dynamic range, nor the sensitivity, crucial to observe
  the faintest solar HXRs. The Focusing Optics X-ray Solar Imager (FOXSI)
  sounding rocket payload is a novel experiment that develops and applies
  direct focusing optics coupled with semiconductor detectors to observe
  faint HXRs from the Sun. The FOXSI rocket has successfully completed
  two flights, observing areas of the quiet-Sun, active regions and
  micro-flares. We present recent data analysis to test the presence of
  hot plasma in and outside of active regions observed during the two
  flights, focusing on the differential emission measure distribution
  of the non-flaring corona.

Title: Optical alignment of the Chromospheric Lyman-Alpha
    Spectro-Polarimeter using sophisticated methods to minimize activities
    under vacuum
Authors: Giono, G.; Katsukawa, Y.; Ishikawa, R.; Narukage, N.;
   Kano, R.; Kubo, M.; Ishikawa, S.; Bando, T.; Hara, H.; Suematsu, Y.;
   Winebarger, A.; Kobayashi, K.; Auchère, F.; Trujillo Bueno, J.
Bibcode: 2016SPIE.9905E..3DG
Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a
  sounding-rocket instrument developed at the National Astronomical
  Observatory of Japan (NAOJ) as a part of an international
  collaboration. The instrument main scientific goal is to achieve
  polarization measurement of the Lyman-α line at 121.56 nm emitted from
  the solar upper-chromosphere and transition region with an unprecedented
  0.1% accuracy. The optics are composed of a Cassegrain telescope
  coated with a "cold mirror" coating optimized for UV reflection and
  a dual-channel spectrograph allowing for simultaneous observation of
  the two orthogonal states of polarization. Although the polarization
  sensitivity is the most important aspect of the instrument, the spatial
  and spectral resolutions of the instrument are also crucial to observe
  the chromospheric features and resolve the Ly-α profiles. A precise
  alignment of the optics is required to ensure the resolutions, but
  experiments under vacuum conditions are needed since Ly-α is absorbed
  by air, making the alignment experiments difficult. To bypass this
  issue, we developed methods to align the telescope and the spectrograph
  separately in visible light. We explain these methods and present
  the results for the optical alignment of the CLASP telescope and
  spectrograph. We then discuss the combined performances of both parts
  to derive the expected resolutions of the instrument, and compare them
  with the flight observations performed on September 3<SUP>rd</SUP> 2015.

Title: Chromospheric LAyer SpectroPolarimeter (CLASP2)
Authors: Narukage, Noriyuki; McKenzie, David E.; Ishikawa, Ryoko;
   Trujillo-Bueno, Javier; De Pontieu, Bart; Kubo, Masahito; Ishikawa,
   Shin-nosuke; Kano, Ryouhei; Suematsu, Yoshinori; Yoshida, Masaki;
   Rachmeler, Laurel A.; Kobayashi, Ken; Cirtain, Jonathan W.; Winebarger,
   Amy R.; Asensio Ramos, Andres; del Pino Aleman, Tanausu; Štępán,
   Jiri; Belluzzi, Luca; Larruquert, Juan Ignacio; Auchère, Frédéric;
   Leenaarts, Jorrit; Carlsson, Mattias J. L.
Bibcode: 2016SPIE.9905E..08N
Altcode:
  The sounding rocket Chromospheric Lyman-Alpha SpectroPolarimeter
  (CLASP) was launched on September 3rd, 2015, and successfully detected
  (with a polarization accuracy of 0.1 %) the linear polarization signals
  (Stokes Q and U) that scattering processes were predicted to produce
  in the hydrogen Lyman-alpha line (Lyα 121.567 nm). Via the Hanle
  effect, this unique data set may provide novel information about the
  magnetic structure and energetics in the upper solar chromosphere. The
  CLASP instrument was safely recovered without any damage and we have
  recently proposed to dedicate its second flight to observe the four
  Stokes profiles in the spectral region of the Mg II h and k lines
  around 280 nm; in these lines the polarization signals result from
  scattering processes and the Hanle and Zeeman effects. Here we describe
  the modifications needed to develop this new instrument called the
  "Chromospheric LAyer SpectroPolarimeter" (CLASP2).

Title: Evidence of Electron Acceleration around the Reconnection
    X-point in a Solar Flare
Authors: Narukage, Noriyuki; Shimojo, Masumi; Sakao, Taro
Bibcode: 2016SPD....4730202N
Altcode:
  Particle acceleration is one of the most significant features that
  are ubiquitous among space and cosmic plasmas. It is most prominent
  during flares in the case of the Sun, with which huge amounts of
  electromagnetic radiation and high-energy particles are expelled into
  the interplanetary space through acceleration of plasma particles
  in the corona. Though it has been well understood that energies of
  flares are supplied by the mechanism called magnetic reconnection
  based on the observations in X-rays and EUV with space telescopes,
  where and how in the flaring magnetic field plasmas are accelerated
  has remained unknown due to the low plasma density in the flaring
  corona. We here report the first observational identification of the
  energetic non-thermal electrons around the point of the ongoing magnetic
  reconnection (X-point), with the location of the X-point identified
  by soft X-ray imagery and the localized presence of non-thermal
  electrons identified from imaging-spectroscopic data at two microwave
  frequencies. Considering the existence of the reconnection outflows
  that carries both plasma particles and magnetic fields out from
  the X-point, our identified non-thermal microwave emissions around
  the X-point indicate that the electrons are accelerated around the
  reconnection X-point.

Title: Spectro-polarimetric observation in UV with CLASP to probe
    the chromosphere and transition region
Authors: Kano, Ryouhei; Ishikawa, Ryohko; Winebarger, Amy R.; Auchère,
   Frédéric; Trujillo Bueno, Javier; Narukage, Noriyuki; Kobayashi,
   Ken; Bando, Takamasa; Katsukawa, Yukio; Kubo, Masahito; Ishikawa,
   Shin-Nosuke; Giono, Gabriel; Hara, Hirohisa; Suematsu, Yoshinori;
   Shimizu, Toshifumi; Sakao, Taro; Tsuneta, Saku; Ichimoto, Kiyoshi;
   Goto, Motoshi; Cirtain, Jonathan W.; De Pontieu, Bart; Casini, Roberto;
   Manso Sainz, Rafael; Asensio Ramos, Andres; Stepan, Jiri; Belluzzi,
   Luca; Carlsson, Mats
Bibcode: 2016SPD....4710107K
Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a NASA
  sounding-rocket experiment that was performed in White Sands in
  the US on September 3, 2015. During its 5-minute ballistic flight,
  CLASP successfully made the first spectro-polarimetric observation in
  the Lyman-alpha line (121.57 nm) originating in the chromosphere and
  transition region. Since the Lyman-alpha polarization is sensitive
  to magnetic field of 10-100 G by the Hanle effect, we aim to infer
  the magnetic field information in such upper solar atmosphere with
  this experiment.The obtained CLASP data showed that the Lyman-alpha
  scattering polarization is about a few percent in the wings and
  the order of 0.1% in the core near the solar limb, as it had been
  theoretically predicted, and that both polarization signals have a
  conspicuous spatio-temporal variability. CLASP also observed another
  upper-chromospheric line, Si III (120.65 nm), whose critical field
  strength for the Hanle effect is 290 G, and showed a measurable
  scattering polarization of a few % in this line. The polarization
  properties of the Si III line could facilitate the interpretation of
  the scattering polarization observed in the Lyman-alpha line.In this
  presentation, we would like to show how the upper chromosphere and
  transition region are seen in the polarization of these UV lines and
  discuss the possible source of these complicated polarization signals.

Title: Development of precision Wolter mirrors for future solar
    x-ray observations
Authors: Sakao, Taro; Matsuyama, Satoshi; Kime, Ayumi; Goto, Takumi;
   Nishihara, Akihiko; Nakamori, Hiroki; Yamauchi, Kazuto; Kohmura,
   Yoshiki; Miyake, Akira; Hashizume, Hirokazu; Maezawa, Tadakazu;
   Suematsu, Yoshinori; Narukage, Noriyuki
Bibcode: 2015SPIE.9603E..0US
Altcode:
  High resolution imagery of the solar X-ray corona provides a
  crucial key to understand dynamics and heating processes of plasma
  particles there. However, X-ray imagery of the Sun with sub-arcsecond
  resolution has yet to be conducted due to severe technical difficulty in
  fabricating precision Wolter mirrors. For future X-ray observations of
  the Sun's corona, we are attempting to realize precision Wolter mirrors
  with sub-arcsecond resolution by adopting advanced surface polish and
  metrology methods based on nano-technology to sector mirrors which
  consist of a portion of an entire annulus. Following fabrication
  of the first engineering mirror and subsequent evaluation on the
  X-ray focusing performance in 2013, the second engineering mirror
  was made with improvements in both precision polish and metrology
  introduced. Measurement of focusing performance on the second mirror
  at SPring-8 synchrotron facility with 8 keV X-rays has demonstrated
  that the FWHM size of the PSF core reached down to 0.2" while its HPD
  (Half Power Diameter) size remained at ~3" due to the presence of
  small-angle scatter just outside of the core. Also, there was notable
  difference in the focal length between sagittal and meridional focusing
  which could have been caused by an error in the sag in the meridional
  direction of &lt;10 nm in the mirror area. Further improvements to
  overcome these issues have been planned for the next engineering mirror.

Title: CLASP: A UV Spectropolarimeter on a Sounding Rocket for
    Probing theChromosphere-Corona Transition Regio
Authors: Ishikawa, Ryohko; Kano, Ryouhei; Winebarger, Amy; Auchere,
   Frederic; Trujillo Bueno, Javier; Bando, Takamasa; Narukage,
   Noriyuki; Kobayashi, Ken; Katsukawa, Yukio; Kubo, Masahito; Ishikawa,
   Shin-nosuke; Giono, Gabriel; Tsuneta, Saku; Hara, Hirohisa; Suematsu,
   Yoshinori; Shimizu, Toshifumi; Sakao, Taro; Ichimoto, Kiyoshi;
   Cirtain, Jonathan; De Pontieu, Bart; Casini, Roberto; Manso Sainz,
   Rafael; Asensio Ramos, Andres; Stepan, Jiri; Belluzzi, Luca
Bibcode: 2015IAUGA..2254536I
Altcode:
  The wish to understand the energetic phenomena of the outer solar
  atmosphere makes it increasingly important to achieve quantitative
  information on the magnetic field in the chromosphere-corona
  transition region. To this end, we need to measure and model the
  linear polarization produced by scattering processes and the Hanle
  effect in strong UV resonance lines, such as the hydrogen Lyman-alpha
  line. A team consisting of Japan, USA, Spain, France, and Norway has
  been developing a sounding rocket experiment called the Chromospheric
  Lyman-alpha Spectro-Polarimeter (CLASP). The aim is to detect the
  scattering polarization produced by anisotropic radiation pumping in
  the hydrogen Lyman-alpha line (121.6 nm), and via the Hanle effect to
  try to constrain the magnetic field vector in the upper chromosphere
  and transition region. In this talk, we will present an overview
  of our CLASP mission, its scientific objectives, ground tests made,
  and the latest information on the launch planned for the Summer of 2015.

Title: Strategy for Realizing High-Precision VUV Spectro-Polarimeter
Authors: Ishikawa, R.; Narukage, N.; Kubo, M.; Ishikawa, S.; Kano,
   R.; Tsuneta, S.
Bibcode: 2014SoPh..289.4727I
Altcode: 2014SoPh..tmp..116I
  Spectro-polarimetric observations in the vacuum ultraviolet (VUV)
  range are currently the only means to measure magnetic fields in the
  upper chromosphere and transition region of the solar atmosphere. The
  Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) aims to measure
  linear polarization at the hydrogen Lyman-α line (121.6 nm). This
  measurement requires a polarization sensitivity better than 0.1 %,
  which is unprecedented in the VUV range. We here present a strategy with
  which to realize such high-precision spectro-polarimetry. This involves
  the optimization of instrument design, testing of optical components,
  extensive analyses of polarization errors, polarization calibration
  of the instrument, and calibration with onboard data. We expect that
  this strategy will aid the development of other advanced high-precision
  polarimeters in the UV as well as in other wavelength ranges.

Title: Precision VUV Spectro-Polarimetry for Solar Chromospheric
    Magnetic Field Measurements
Authors: Ishikawa, R.; Bando, T.; Hara, H.; Ishikawa, S.; Kano, R.;
   Kubo, M.; Katsukawa, Y.; Kobiki, T.; Narukage, N.; Suematsu, Y.;
   Tsuneta, S.; Aoki, K.; Miyagawa, K.; Ichimoto, K.; Kobayashi, K.;
   Auchère, F.; Clasp Team
Bibcode: 2014ASPC..489..319I
Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a VUV
  spectro-polarimeter optimized for measuring the linear polarization
  of the Lyman-α line (121.6 nm) to be launched in 2015 with NASA's
  sounding rocket (Ishikawa et al. 2011; Narukage et al. 2011; Kano et
  al. 2012; Kobayashi et al. 2012). With this experiment, we aim to (1)
  observe the scattering polarization in the Lyman-α line, (2) detect
  the Hanle effect, and (3) assess the magnetic fields in the upper
  chromosphere and transition region for the first time. The polarization
  measurement error consists of scale error δ a (error in amplitude
  of linear polarization), azimuth error Δφ (error in the direction
  of linear polarization), and spurious polarization ɛ (false linear
  polarization signals). The error ɛ should be suppressed below 0.1%
  in the Lyman-α core (121.567 nm ±0.02 nm), and 0.5% in the Lyman-α
  wing (121.567 nm ±0.05 nm), based on our scientific requirements shown
  in Table 2 of Kubo et al. (2014). From scientific justification, we
  adopt Δ φ&lt;2° and δ a&lt;10% as the instrument requirements. The
  spectro-polarimeter features a continuously rotating MgF<SUB>2</SUB>
  waveplate (Ishikawa et al. 2013), a dual-beam spectrograph with a
  spherical grating working also as a beam splitter, and two polarization
  analyzers (Bridou et al. 2011), which are mounted at 90 degree from
  each other to measure two orthogonal polarization simultaneously. For
  the optical layout of the CLASP instrument, see Figure 3 in Kubo et
  al. (2014). Considering the continuous rotation of the half-waveplate,
  the modulation efficiency is 0.64 both for Stokes Q and U. All the raw
  data are returned and demodulation (successive addition or subtraction
  of images) is done on the ground. <P />We control the CLASP polarization
  performance in the following three steps. First, we evaluate the
  throughput and polarization properties of each optical component in
  the Lyman-α line, using the Ultraviolet Synchrotron ORbital Radiation
  Facility (UVSOR) at the Institute for Molecular Science. The second
  step is polarization calibration of the spectro-polarimeter after
  alignment. Since the spurious polarization caused by the axisymmetric
  telescope is estimated to be negligibly small because of the symmetry
  (Ishikawa et al. 2014), we do not perform end-to-end polarization
  calibration. As the final step, before the scientific observation near
  the limb, we make a short observation at the Sun center and verify
  the polarization sensitivity, because the scattering polarization
  is expected to be close to zero at the Sun center due to symmetric
  geometry. In order to clarify whether we will be able to achieve the
  required polarization sensitivity and accuracy via these steps, we
  exercise polarization error budget, by investigating all the possible
  causes and their magnitudes of polarization errors, all of which are not
  necessarily verified by the polarization calibration. Based on these
  error budgets, we conclude that a polarization sensitivity of 0.1% in
  the line core, δ a&lt;10% and Δ φ&lt;2° can be achieved combined
  with the polarization calibration of the spectro-polarimeter and the
  onboard calibration at the Sun center(refer to Ishikawa et al. 2014,
  for the detail). <P />We are currently conducting verification tests
  of the flight components and development of the UV light source for
  the polarization calibration. From 2014 spring, we will begin the
  integration, alignment, and calibration. We will update the error
  budgets throughout the course of these tests.

Title: A Sounding Rocket Experiment for the Chromospheric Lyman-Alpha
    Spectro-Polarimeter (CLASP)
Authors: Kubo, M.; Kano, R.; Kobayashi, K.; Bando, T.; Narukage, N.;
   Ishikawa, R.; Tsuneta, S.; Katsukawa, Y.; Ishikawa, S.; Suematsu, Y.;
   Hara, H.; Shimizu, T.; Sakao, T.; Ichimoto, K.; Goto, M.; Holloway,
   T.; Winebarger, A.; Cirtain, J.; De Pontieu, B.; Casini, R.; Auchère,
   F.; Trujillo Bueno, J.; Manso Sainz, R.; Belluzzi, L.; Asensio Ramos,
   A.; Štěpán, J.; Carlsson, M.
Bibcode: 2014ASPC..489..307K
Altcode:
  A sounding-rocket experiment called the Chromospheric Lyman-Alpha
  Spectro-Polarimeter (CLASP) is presently under development to measure
  the linear polarization profiles in the hydrogen Lyman-alpha (Lyα)
  line at 121.567 nm. CLASP is a vacuum-UV (VUV) spectropolarimeter to aim
  for first detection of the linear polarizations caused by scattering
  processes and the Hanle effect in the Lyα line with high accuracy
  (0.1%). This is a fist step for exploration of magnetic fields in
  the upper chromosphere and transition region of the Sun. Accurate
  measurements of the linear polarization signals caused by scattering
  processes and the Hanle effect in strong UV lines like Lyα are
  essential to explore with future solar telescopes the strength
  and structures of the magnetic field in the upper chromosphere and
  transition region of the Sun. The CLASP proposal has been accepted by
  NASA in 2012, and the flight is planned in 2015.

Title: Current progress of optical alignment procedure of CLASP's
    Lyman-alpha polarimetry instrument
Authors: Giono, G.; Ishikawa, R.; Katsukawa, Y.; Bando, T.; Kano, R.;
   Suematsu, Y.; Narukage, N.; Sakao, Taro; Kobayashi, K.; Auchère, F.
Bibcode: 2014SPIE.9144E..3EG
Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a
  sounding-rocket instrument currently under development at the
  National Astronomical Observatory of Japan (NAOJ) as a part of an
  international collaboration. CLASP's optics are composed of a Cassegrain
  telescope and a spectro-polarimeter which are designed to achieve an
  unprecedentedly accurate polarization measurement of the Ly-α line
  at 121.6nm emitted from the solar upper-chromosphere and transition
  region. CLASP's first flight is scheduled for August 2015. Reaching
  such accuracy requires a careful alignment of the optical elements
  to optimize the image quality at 121.6 nm. However Ly-α is absorbed
  by air and therefore the optics alignment has to be done under vacuum
  condition which makes any experiment difficult. To bypass this issue,
  we proposed to align the telescope and the spectrograph separately
  in visible light. Hence we present our alignment procedure for both
  telescope and spectro-polarimeter. We will explain details about the
  telescope preliminary alignment before mirrors coating, which was done
  in April 2014, present the telescope combined optical performance
  and compare them to CLASP tolerance. Then we will present details
  about an experiment designed to confirm our alignment procedure for
  the CLASP spectro-polarimeter. We will discuss the resulting image
  quality achieved during this experiment and the lessons learned.

Title: The soft x-ray photon-counting telescope for solar observations
Authors: Sakao, Taro; Narukage, Noriyuki; Suematsu, Yoshinori;
   Watanabe, Kyoko; Shimojo, Masumi; Imada, Shinsuke; Ishikawa,
   Shin-nosuke; DeLuca, Edward E.
Bibcode: 2014SPIE.9144E..3DS
Altcode:
  We present overview and development activities of a soft X-ray
  photon-counting spectroscopic imager for the solar corona that
  we conceive as a possible scientific payload for future space
  solar missions including Japanese Solar-C. The soft X-ray imager
  will employ a Wolter I grazing-incidence sector mirror with which
  images of the corona (1 MK to beyond 10 MK) will be taken with
  the highest-ever angular resolution (0.5"/pixel for a focal length
  of 4 m) as a solar Xray telescope. In addition to high-resolution
  imagery, we attempt to implement photon-counting capability for the
  imager by employing a backside-illuminated CMOS image sensor as the
  focal-plane device. Imaging-spectroscopy of the X-ray corona will be
  performed for the first time in the energy range from ~0.5 keV up to
  10 keV. The imaging-spectroscopic observations with the soft X-ray
  imager will provide a noble probe for investigating mechanism(s) of
  magnetic reconnection and generation of supra-thermal (non-thermal)
  electrons associated with flares. Ongoing development activities in
  Japan towards the photon-counting imager is described with emphasis
  on that for sub-arcsecond-resolution grazing-incidence mirrors.

Title: Evidence of Electron Acceleration around the Reconnection
    X-point in a Solar Flare
Authors: Narukage, Noriyuki; Shimojo, Masumi; Sakao, Taro
Bibcode: 2014ApJ...787..125N
Altcode: 2014arXiv1404.3288N
  Particle acceleration is one of the most significant features that
  are ubiquitous among space and cosmic plasmas. It is most prominent
  during flares in the case of the Sun, with which huge amounts of
  electromagnetic radiation and high-energy particles are expelled into
  the interplanetary space through acceleration of plasma particles
  in the corona. Though it has been well understood that energies of
  flares are supplied by the mechanism called magnetic reconnection
  based on the observations in X-rays and EUV with space telescopes,
  where and how in the flaring magnetic field plasmas are accelerated
  has remained unknown due to the low plasma density in the flaring
  corona. We here report the first observational identification of the
  energetic non-thermal electrons around the point of the ongoing magnetic
  reconnection (X-point), with the location of the X-point identified
  by soft X-ray imagery and the localized presence of non-thermal
  electrons identified from imaging-spectroscopic data at two microwave
  frequencies. Considering the existence of the reconnection outflows
  that carries both plasma particles and magnetic fields out from
  the X-point, our identified non-thermal microwave emissions around
  the X-point indicate that the electrons are accelerated around the
  reconnection X-point. Additionally, the plasma around the X-point was
  also thermally heated up to 10 MK. The estimated reconnection rate of
  this event is ~0.017.

Title: Coronal-Temperature-Diagnostic Capability of the Hinode/ X-Ray
    Telescope Based on Self-consistent Calibration. II. Calibration with
    On-Orbit Data
Authors: Narukage, N.; Sakao, T.; Kano, R.; Shimojo, M.; Winebarger,
   A.; Weber, M.; Reeves, K. K.
Bibcode: 2014SoPh..289.1029N
Altcode: 2013arXiv1307.4489N
  The X-Ray Telescope (XRT) onboard the Hinode satellite is an
  X-ray imager that observes the solar corona with the capability of
  diagnosing coronal temperatures from less than 1 MK to more than
  10 MK. To make full use of this capability, Narukage et al. (Solar
  Phys.269, 169, 2011) determined the thickness of each of the X-ray
  focal-plane analysis filters based on calibration measurements
  from the ground-based end-to-end test. However, in their paper,
  the calibration of the thicker filters for observations of active
  regions and flares, namely the med-Be, med-Al, thick-Al and thick-Be
  filters, was insufficient due to the insufficient X-ray flux used in
  the measurements. In this work, we recalibrate those thicker filters
  using quiescent active region data taken with multiple filters of
  XRT. On the basis of our updated calibration results, we present the
  revised coronal-temperature-diagnostic capability of XRT.

Title: Within the International Collaboration CHAIN: a Summary of
    Events Observed with Flare Monitoring Telescope (FMT) in Peru
Authors: Ishitsuka, J.; Asai, A.; Morita, S.; Terrazas, R.; Cabezas,
   D.; Gutierrez, V.; Martinez, L.; Buleje, Y.; Loayza, R.; Nakamura,
   N.; Takasao, S.; Yoshinaga, Y.; Hillier, A.; Otsuji, K.; Shibata, K.;
   Ishitsuka, M.; Ueno, S.; Kitai, R.; Ishii, T.; Ichimoto, K.; Nagata,
   S.; Narukage, N.
Bibcode: 2014SunGe...9...85I
Altcode:
  In 2008 we inaugurated the new Solar Observatory in collaboration with
  Faculty of Sciences of San Luis Gonzaga de Ica National University,
  300 km south of Lima. In March of 2010 a Flare Monitoring Telescope
  of Hida Observatory of Kyoto University arrived to Ica, part of CHAIN
  Project (Continuous H-alpha Imaging Network). In October of the same
  year we hosted the First FMT Workshop in Ica, then in July of 2011 the
  Second FMT Workshop was opened. Since that we are focused on two events
  registered by FMT in Peru to publish results. FMT is a good tool to
  introduce young people from universities into scientific knowledge;
  it is good also for education in Solar Physics and outreach. Details
  of this successful collaboration will be explained in this presentation.

Title: Chromospheric Lyman-alpha spectro-polarimeter (CLASP)
Authors: Kano, Ryouhei; Katsukawa, Yukio; Kubo, Masahito; Auchere,
   Frederic; Ishikawa, Ryohko; Kobayashi, Ken; Narukage, Noriyuki;
   Trujillo Bueno, Javier; Bando, Takamasa; Ishikawa, Shin-nosuke
Bibcode: 2014cosp...40E1383K
Altcode:
  In the solar chromosphere, magneto-hydrodynamic waves and super-sonic
  jets ubiquitously happen as revealed by the Japanese solar satellite
  Hinode. Now, we understand that the solar chromosphere is not a simple
  intermediate layer smoothly connecting the photosphere and corona,
  but a site where those dynamics may play an important role in the
  chromospheric and coronal heating. Such discoveries imply that the
  next frontier in solar physics lies in simultaneous observations
  between the dynamics and magnetic structures in the chromosphere and
  transition region, where the gas-dominant photosphere changes to the
  magnetic-dominant corona. Therefore, we promote the Chromospheric
  Lyman-Alpha SpectroPolarimeter (CLASP), which is a NASA's sounding
  rocket experiment scheduled in 2015 for aiming to infer the magnetic
  field information in the solar chromosphere and transition region. CLASP
  makes precise measurement (0.1%) of the polarization profile of the
  Lyman-alpha line, and aims to make the first ever measurement of the
  Hanle effect polarization caused by magnetic fields in the upper solar
  atmosphere. It is also a pathfinder to establish a new measurement
  tool for chromospheric and transition-region magnetic fields, and to
  make progress on chromospheric studies in future missions.

Title: UV spectropolarimeter design for precise polarization
    measurement and its application to the CLASP for exploration of
    magnetic fields in solar atmosphere
Authors: Narukage, Noriyuki; Katsukawa, Yukio; Hara, Hirohisa; Kubo,
   Masahito; Auchere, Frederic; Ishikawa, Ryohko; Kano, Ryouhei; Bando,
   Takamasa; Ishikawa, Shin-nosuke; Suematsu, Yoshinori; Tsuneta, Saku
Bibcode: 2014cosp...40E2232N
Altcode:
  In order to measure the magnetic field in the region where the
  hot plasma from 10 (4) K to 10 (6) K is occupied, e.g., for solar
  atmosphere, the polarimetric measurements in ultra violet (UV)
  with 0.1% accuracy are required. In this paper, we propose a new
  UV spectropolarimeter design with 0.1% sensitivity in polarization
  measurement. This spectropolarimeter has two devices for the 0.1%
  accuracy. First, all optical components except the waveplate are the
  reflective type ones that can be equipped with the high reflectivity
  coating for the high throughput. Secondly, it equips the optically
  symmetric dual channels to measure the orthogonal linear polarization
  state simultaneously, using a concave diffraction grating as both the
  spectral dispersion element and the beam splitter. These two devices
  make the spurious polarizations caused by the photon noise, by the
  intensity variation of the observation target, and, by the instrument
  itself, enough small to achieve the 0.1% accuracy in polarization
  measurement. The spectropolarimeter thus designed is currently under
  fabrication for the sounding rocket project of Chromospheric Lyman-Alpha
  SpectroPolarimeter (CLASP) that aims at the direct measurement of the
  magnetic fields in solar atmosphere with Lyman-alpha line (121.6 nm)
  for the first time.

Title: Chromospheric Lyman Alpha SpectroPolarimeter: CLASP
Authors: Kobayashi, Ken; Kano, R.; Trujillo Bueno, J.; Winebarger,
   A. R.; Cirtain, J. W.; Bando, T.; De Pontieu, B.; Ishikawa, R.;
   Katsukawa, Y.; Kubo, M.; Narukage, N.; Sakao, T.; Tsuneta, S.;
   Auchère, F.; Asensio Ramos, A.; Belluzzi, L.; Carlsson, M.; Casini,
   R.; Hara, H.; Ichimoto, K.; Manso Sainz, R.; Shimizu, T.; Stepan,
   J.; Suematsu, Y.; Holloway, T.
Bibcode: 2013SPD....44..142K
Altcode:
  The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a VUV
  spectropolarimeter optimized for measuring the linear polarization of
  the Lyman-alpha line (121.6 nm). The Lyman-alpha line is predicted to
  show linear polarization caused by atomic scattering in the chromosphere
  and modified by the magnetic field through the Hanle effect. The
  Hanle effect is sensitive to weaker magnetic fields than Zeeman
  effect, and is not canceled by opposing fields, making it sensitive
  to tangled or unresolved magnetic field structures. These factors make
  the Hanle effect a valuable tool for probing the magnetic field in the
  chromosphere above the quiet sun. To meet this goal, CLASP is designed
  to measure linear polarization with 0.1% polarization sensitivity
  at 0.01 nm spectral resolution and 10" spatial resolution. CLASP is
  scheduled to be launched in 2015.

Title: Temporal and Spatial Analyses of Spectral Indices of Nonthermal
    Emissions Derived from Hard X-Rays and Microwaves
Authors: Asai, Ayumi; Kiyohara, Junko; Takasaki, Hiroyuki; Narukage,
   Noriyuki; Yokoyama, Takaaki; Masuda, Satoshi; Shimojo, Masumi;
   Nakajima, Hiroshi
Bibcode: 2013ApJ...763...87A
Altcode: 2012arXiv1212.1806A
  We studied electron spectral indices of nonthermal emissions seen in
  hard X-rays (HXRs) and microwaves. We analyzed 12 flares observed by
  the Hard X-Ray Telescope aboard Yohkoh, Nobeyama Radio Polarimeters,
  and the Nobeyama Radioheliograph (NoRH), and compared the spectral
  indices derived from total fluxes of HXRs and microwaves. Except
  for four events, which have very soft HXR spectra suffering from the
  thermal component, these flares show a gap Δδ between the electron
  spectral indices derived from HXRs δ<SUB> X </SUB> and those from
  microwaves δ<SUB>μ</SUB> (Δδ = δ<SUB> X </SUB> - δ<SUB>μ</SUB>)
  of about 1.6. Furthermore, from the start to the peak times of the
  HXR bursts, the time profiles of the HXR spectral index δ<SUB>
  X </SUB> evolve synchronously with those of the microwave spectral
  index δ<SUB>μ</SUB>, keeping the constant gap. We also examined the
  spatially resolved distribution of the microwave spectral index by
  using NoRH data. The microwave spectral index δ<SUB>μ</SUB> tends
  to be larger, which means a softer spectrum, at HXR footpoint sources
  with stronger magnetic field than that at the loop tops. These results
  suggest that the electron spectra are bent at around several hundreds
  of keV, and become harder at the higher energy range that contributes
  the microwave gyrosynchrotron emission.

Title: Chromospheric Lyman-alpha spectro-polarimeter (CLASP)
Authors: Kano, Ryouhei; Bando, Takamasa; Narukage, Noriyuki; Ishikawa,
   Ryoko; Tsuneta, Saku; Katsukawa, Yukio; Kubo, Masahito; Ishikawa,
   Shin-nosuke; Hara, Hirohisa; Shimizu, Toshifumi; Suematsu, Yoshinori;
   Ichimoto, Kiyoshi; Sakao, Taro; Goto, Motoshi; Kato, Yoshiaki; Imada,
   Shinsuke; Kobayashi, Ken; Holloway, Todd; Winebarger, Amy; Cirtain,
   Jonathan; De Pontieu, Bart; Casini, Roberto; Trujillo Bueno, Javier;
   Štepán, Jiří; Manso Sainz, Rafael; Belluzzi, Luca; Asensio Ramos,
   Andres; Auchère, Frédéric; Carlsson, Mats
Bibcode: 2012SPIE.8443E..4FK
Altcode:
  One of the biggest challenges in heliophysics is to decipher the
  magnetic structure of the solar chromosphere. The importance of
  measuring the chromospheric magnetic field is due to both the key role
  the chromosphere plays in energizing and structuring the outer solar
  atmosphere and the inability of extrapolation of photospheric fields to
  adequately describe this key boundary region. Over the last few years,
  significant progress has been made in the spectral line formation
  of UV lines as well as the MHD modeling of the solar atmosphere. It
  is found that the Hanle effect in the Lyman-alpha line (121.567 nm)
  is a most promising diagnostic tool for weaker magnetic fields in
  the chromosphere and transition region. Based on this groundbreaking
  research, we propose the Chromospheric Lyman-Alpha Spectro-Polarimeter
  (CLASP) to NASA as a sounding rocket experiment, for making the first
  measurement of the linear polarization produced by scattering processes
  and the Hanle effect in the Lyman-alpha line (121.567 nm), and making
  the first exploration of the magnetic field in the upper chromosphere
  and transition region of the Sun. The CLASP instrument consists
  of a Cassegrain telescope, a rotating 1/2-wave plate, a dual-beam
  spectrograph assembly with a grating working as a beam splitter, and
  an identical pair of reflective polarization analyzers each equipped
  with a CCD camera. We propose to launch CLASP in December 2014.

Title: The x-ray/EUV telescope for the Solar-C mission: science and
    development activities
Authors: Sakao, Taro; Narukage, Noriyuki; Imada, Shinsuke; Suematsu,
   Yoshinori; Shimojo, Masumi; Tsuneta, Saku; DeLuca, Edward E.; Watanabe,
   Kyoko; Ishikawa, Shin-nosuke
Bibcode: 2012SPIE.8443E..0AS
Altcode:
  We report science and development activities of the X-ray/EUV telescope
  for the Japanese Solar-C mission whose projected launch around 2019. The
  telescope consists of a package of (a) a normal-incidence (NI) EUV
  telescope and (b) a grazing-incidence (GI) soft X-ray telescope. The NI
  telescope chiefly provides images of low corona (whose temperature 1
  MK or even lower) with ultra-high angular resolution (0.2-0.3"/pixel)
  in 3 wavelength bands (304, 171, and 94 angstroms). On the other
  hand, the GI telescope provides images of the corona with a wide
  temperature coverage (1 MK to beyond 10 MK) with the highest-ever
  angular resolution (~0.5"/pixel) as a soft X-ray coronal imager. The
  set of NI and GI telescopes should provide crucial information for
  establishing magnetic and gas-dynamic connection between the corona and
  the lower atmosphere of the Sun which is essential for understanding
  heating of, and plasma activities in, the corona. Moreover, we attempt
  to implement photon-counting capability for the GI telescope with
  which imaging-spectroscopy of the X-ray corona will be performed for
  the first time, in the energy range from ~0.5 keV up to 10 keV. The
  imaging-spectroscopic observations will provide totally-new information
  on mechanism(s) for the generation of hot coronal plasmas (heated
  beyond a few MK), those for magnetic reconnection, and even generation
  of supra-thermal electrons associated with flares. An overview of
  instrument outline and science for the X-ray photoncounting telescope
  are presented, together with ongoing development activities in Japan
  towards soft X-ray photoncounting observations, focusing on high-speed
  X-ray CMOS detector and sub-arcsecond-resolution GI mirror.

Title: The Chromospheric Lyman-Alpha SpectroPolarimeter: CLASP
Authors: Kobayashi, K.; Kano, R.; Trujillo-Bueno, J.; Asensio Ramos,
   A.; Bando, T.; Belluzzi, L.; Carlsson, M.; De Pontieu, R. C. B.; Hara,
   H.; Ichimoto, K.; Ishikawa, R.; Katsukawa, Y.; Kubo, M.; Manso Sainz,
   R.; Narukage, N.; Sakao, T.; Stepan, J.; Suematsu, Y.; Tsuneta, S.;
   Watanabe, H.; Winebarger, A.
Bibcode: 2012ASPC..456..233K
Altcode:
  The magnetic field plays a crucial role in the chromosphere and the
  transition region, and our poor empirical knowledge of the magnetic
  field in the upper chromosphere and transition region is a major
  impediment to advancing the understanding of the solar atmosphere. The
  Hanle effect promises to be a valuable alternative to Zeeman effect
  as a method of measuring the magnetic field in the chromosphere and
  transition region; it is sensitive to weaker magnetic fields, and
  also sensitive to tangled, unresolved field structures. <P />CLASP
  is a sounding rocket experiment that aims to observe the Hanle effect
  polarization of the Lyman α (1215.67Å) line in the solar chromosphere
  and transition region, and prove the usefulness of this technique in
  placing constraints on the magnetic field strength and orientation
  in the low plasma-β region of the solar atmosphere. The Ly-α line
  has been chosen because it is a chromospheric/transition-region line,
  and because the Hanle effect polarization of this line is predicted to
  be sensitive to 10-250 Gauss, encompassing the range of interest. The
  CLASP instrument is designed to measure linear polarization in the
  Ly-α line with a polarization sensitivity of 0.1%. The instrument is
  currently funded for development. The optical design of the instrument
  has been finalized, and an extensive series of component-level tests
  are underway to validate the design.

Title: Ly-alpha polarimeter design for CLASP rocket experiment
Authors: Kubo, M.; Watanabe, H.; Narukage, N.; Ishikawa, R.; Bando,
   T.; Kano, R.; Tsuneta, S.; Kobayashi, K.; Ichimoto, K.; Trujillo Bueno,
   J.; Song, D.
Bibcode: 2011AGUFM.P11F1627K
Altcode:
  A sounding-rocket program called the Chromospheric Lyman-Alpha
  Spectro-Polarimeter (CLASP) is proposed to be launched in the Summer
  of 2014. CLASP will observe the upper solar chromosphere in Ly-alpha
  (121.567 nm), aiming to detect the linear polarization signal produced
  by scattering processes and the Hanle effect for the first time. The
  CLASP needs a rotating half-waveplate and a polarization analyzer
  working at the Ly-alpha wavelength to measure the linear polarization
  signal. We select Magnesium Fluoride (MgF2) as a material of the
  optical components because of its birefringent property and high
  transparency at UV wavelength. We have confirmed that the reflection
  at the Brewster's Angle of MgF2 plate is a good polarization analyzer
  for the Ly-alpha line by deriving its ordinary refractive index and
  extinction coefficient along the ordinary and extraordinary axes. These
  optical parameters are calculated with a least-square fitting in such a
  way that the reflectance and transmittance satisfy the Kramers-Kronig
  relation. The reflectance and transmittance against oblique incident
  angles for the s-polarized and the p-polarized light are measured
  using the synchrotron beamline at the Ultraviolet Synchrotron Orbital
  Radiation Facility (UVSOR). We have also measured a retardation of
  a zeroth-order waveplate made of MgF2. The thickness difference of
  the waveplate is 14.57 um.This waveplate works as a half-waveplate at
  121.74 nm. From this measurement, we estimate that a waveplate with
  the thickness difference of 15.71 um will work as a half-waveplate
  at the Ly-alpha wavelength. We have developed a rotating waveplate -
  polarization analyzer system called a prototype of CLASP polarimeter,
  and input the perfect Stokes Q and U signals. The modulation patterns
  that are consistent with the theoretical prediction are successfully
  obtained in both cases.

Title: The Chromospheric Lyman-Alpha SpectroPolarimeter (CLASP)j
Authors: Kobayashi, K.; Tsuneta, S.; Trujillo Bueno, J.; Bando, T.;
   Belluzzi, L.; Casini, R.; Carlsson, M.; Cirtain, J. W.; De Pontieu,
   B.; Hara, H.; Ichimoto, K.; Ishikawa, R.; Kano, R.; Katsukawa, Y.;
   Kim, T.; Kubo, M.; Manso Sainz, R.; Narukage, N.; Asensio Ramos,
   A.; Robinson, B.; Sakao, T.; Shimizu, T.; Stepan, J.; Suematsu, Y.;
   Watanabe, H.; West, E.; Winebarger, A. R.
Bibcode: 2011AGUFM.P14C..05K
Altcode:
  We present an overview of the Chromospheric Lyman-Alpha
  SpectroPolarimeter (CLASP) program. CLASP is a proposed sounding rocket
  experiment currently under development as collaboration between Japan,
  USA and Spain. The aim is to achieve the first measurement of magnetic
  field in the upper chromosphere and transition region of the Sun
  through the detection and measurement of Hanle effect polarization
  of the Lyman alpha line. The Hanle effect (i.e. the magnetic field
  induced modification of the linear polarization due to scattering
  processes in spectral lines) is believed to be a powerful tool for
  measuring the magnetic field in the upper chromosphere, as it is more
  sensitive to weaker magnetic fields than the Zeeman effect, and also
  sensitive to magnetic fields tangled at spatial scales too small to be
  resolved. The Lyman-alpha (121.567 nm) line has been chosen because
  it is a chromospheric/transition-region line, and because the Hanle
  effect polarization of the Lyman-alpha line is predicted to be sensitive
  to 10-250 Gauss, encompassing the range of interest. Hanle effect is
  predicted to be observable as linear polarization or depolarization,
  depending on the geometry, with a fractional polarization amplitude
  varying between 0.1% and 1% depending on the strength and orientation of
  the magnetic field. This quantification of the chromospheric magnetic
  field requires a highly sensitive polarization measurement. The
  CLASP instrument consists of a large aperture (287 mm) Cassegrain
  telescope mated to a polarizing beamsplitter and a matched pair
  of grating spectrographs. The polarizing beamsplitter consists
  of a continuously rotating waveplate and a linear beamsplitter,
  allowing simultaneous measurement of orthogonal polarizations and
  in-flight self-calibration. Development of the instrument is underway,
  and prototypes of all optical components have been tested using a
  synchrotron beamline. The experiment is proposed for flight in 2014.

Title: Photon-counting soft x-ray telescope for the Solar-C mission
Authors: Sakao, Taro; Narukage, Noriyuki; Shimojo, Masumi; Tsuneta,
   Saku; Suematsu, Yoshinori; Miyazaki, Satoshi; Imada, Shinsuke;
   Nishizuka, Naoto; Watanabe, Kyoko; Dotani, Tadayasu; DeLuca, Edward
   E.; Ishikawa, Shin-nosuke
Bibcode: 2011SPIE.8148E..0CS
Altcode: 2011SPIE.8148E..11S
  We report instrument outline as well as science of the photon-counting
  soft X-ray telescope that we have been studying as a possible scientific
  payload for the Japanese Solar-C mission whose projected launch around
  2019. Soft X-rays (~1- 10 keV) from the solar corona include rich
  information on (1) possible mechanism(s) for heating the bright core of
  active regions seen in soft X-rays (namely, the hottest portion in the
  non-flaring corona), (2) dynamics and magnetohydrodynamic structures
  associated with magnetic reconnection processes ongoing in flares,
  and even (3) generation of supra-thermal distributions of coronal
  plasmas associated with flares. Nevertheless, imaging-spectroscopic
  investigation of the soft X-ray corona has so far remained unexplored
  due to difficulty in the instrumentation for achieving this aim. With
  the advent of recent remarkable progress in CMOS-APS detector
  technology, the photon-counting X-ray telescope will be capable
  of, in addition to conventional photon-integration type exposures,
  performing imaging-spectroscopic investigation on active regions and
  flares, thus providing, for example, detailed temperature information
  (beyond the sofar- utilized filter-ratio temperature) at each spatial
  point of the observing target. The photon-counting X-ray telescope will
  emply a Wolter type I optics with a piece of a segmented mirror whose
  focal length 4 meters, combined with a focal-plane CMOS-APS detector
  (0.4-0.5"/pixel) whose frame read-out rate required to be as high as
  1000 fps.

Title: Ly-alpha polarimeter design for CLASP rocket experiment
Authors: Watanabe, H.; Narukage, N.; Kubo, M.; Ishikawa, R.; Bando, T.;
   Kano, R.; Tsuneta, S.; Kobayashi, K.; Ichimoto, K.; Trujillo-Bueno, J.
Bibcode: 2011SPIE.8148E..0TW
Altcode: 2011SPIE.8148E..25W; 2014arXiv1407.4577W
  A sounding-rocket program called the Chromospheric Lyman-Alpha
  Spectro-Polarimeter (CLASP) is proposed to be launched in the summer of
  2014. CLASP will observe the solar chromosphere in Ly-alpha (121.567
  nm), aiming to detect the linear polarization signal produced by
  scattering processes and the Hanle effect for the first time. The
  polarimeter of CLASP consists of a rotating half-waveplate, a beam
  splitter, and a polarization analyzer. Magnesium Fluoride (MgF2) is
  used for these optical components, because MgF2 exhibits birefringent
  property and high transparency at ultraviolet wavelength. The
  development and comprehensive testing program of the optical components
  of the polarimeter is underway using the synchrotron beamline at the
  Ultraviolet Synchrotron Orbital Radiation Facility (UVSOR). The first
  objective is deriving the optical constants of MgF2 by the measurement
  of the reflectance and transmittance against oblique incident angles
  for the s-polarized and the p-polarized light. The ordinary refractive
  index and extinction coefficient along the ordinary and extraordinary
  axes are derived with a least-square fitting in such a way that the
  reflectance and transmittance satisfy the Kramers-Krönig relation. The
  reflection at the Brewster's Angle of MgF2 plate is confirmed to become
  a good polarization analyzer at Ly-alpha. The second objective is the
  retardation measurement of a zeroth-order waveplate made of MgF2. The
  retardation of a waveplate is determined by observing the modulation
  amplitude that comes out of a waveplate and a polarization analyzer. We
  tested a waveplate with the thickness difference of 14.57 um. The 14.57
  um waveplate worked as a half-waveplate at 121.74 nm. We derived that
  a waveplate with the thickness difference of 15.71 um will work as a
  half-waveplate at Ly-alpha wavelength. We developed a prototype of CLASP
  polarimeter using the MgF2 half-waveplate and polarization analyzers,
  and succeeded in obtaining the modulation patterns that are consistent
  with the theoretical prediction. We confirm that the performance of
  the prototype is optimized for measuring linear polarization signal
  with the least effect of the crosstalk from the circular polarization.

Title: Overview of Chromospheric Lyman-Alpha SpectroPolarimeter
    (CLASP)
Authors: Narukage, Noriyuki; Tsuneta, Saku; Bando, Takamasa; Kano,
   Ryouhei; Kubo, Masahito; Ishikawa, Ryoko; Hara, Hirohisa; Suematsu,
   Yoshinori; Katsukawa, Yukio; Watanabe, Hiroko; Ichimoto, Kiyoshi;
   Sakao, Taro; Shimizu, Toshifumi; Kobayashi, Ken; Robinson, Brian; Kim,
   Tony; Winebarger, Amy; West, Edward; Cirtain, Jonathan; De Pontieu,
   Bart; Casini, Roberto; Trujillo Bueno, Javier; Stepan, Jiri; Manso
   Sainz, Rafael; Belluzzi, Luca; Asensio Ramos, Andres; Carlsson, Mats
Bibcode: 2011SPIE.8148E..0HN
Altcode: 2011SPIE.8148E..16N
  The solar chromosphere is an important boundary, through which all of
  the plasma, magnetic fields and energy in the corona and solar wind
  are supplied. Since the Zeeman splitting is typically smaller than
  the Doppler line broadening in the chromosphere and transition region,
  it is not effective to explore weak magnetic fields. However, this is
  not the case for the Hanle effect, when we have an instrument with
  high polarization sensitivity (~ 0.1%). "Chromospheric Lyman- Alpha
  SpectroPolarimeter (CLASP)" is the sounding rocket experiment to detect
  linear polarization produced by the Hanle effect in Lyman-alpha line
  (121.567 nm) and to make the first direct measurement of magnetic
  fields in the upper chromosphere and lower transition region. To
  achieve the high sensitivity of ~ 0.1% within a rocket flight (5
  minutes) in Lyman-alpha line, which is easily absorbed by materials,
  we design the optical system mainly with reflections. The CLASP
  consists of a classical Cassegrain telescope, a polarimeter and a
  spectrometer. The polarimeter consists of a rotating 1/2-wave plate
  and two reflecting polarization analyzers. One of the analyzer also
  works as a polarization beam splitter to give us two orthogonal linear
  polarizations simultaneously. The CLASP is planned to be launched in
  2014 summer.

Title: Propagation of Moreton Waves
Authors: Zhang, Yuzong; Kitai, Reizaburo; Narukage, Noriyuki;
   Matsumoto, Takuma; Ueno, Satoru; Shibata, Kazunari; Wang, Jingxiu
Bibcode: 2011PASJ...63..685Z
Altcode:
  With the Flare-Monitoring Telescope (FMT) and Solar Magnetic Activity
  Research Telescope (SMART) at Hida observatory of Kyoto University,
  13 events of Moreton waves were captured at Hα center, Hα ±0.5 Å,
  and Hα ±0.8 Å wavebands since 1997. With such samples, we have
  studied the statistical properties of the propagation of Moreton
  waves. Moreton waves were all restricted in sectorial zones with a
  mean value of 92°. However, their accompanying EIT waves, observed
  simultaneously with SOHO/EIT at extreme-ultraviolet wavelength, were
  very isotropic with a quite extended scope of 193°. The average
  propagation speeds of the Moreton waves and the corresponding
  EIT waves were 664 km s<SUP>-1</SUP> and 205 km s<SUP>-1</SUP>,
  respectively. Moreton waves propagated either under large-scale
  close magnetic flux loops, or firstly in the sectorial region where
  two sets of magnetic loops separated from each other and diverged,
  and then stopped before the open magnetic flux region. The location
  swept by Moreton waves had a relatively weak magnetic field as compared
  to the magnetic fields at their sidewalls. The ratio of the magnetic
  flux density between the sidewall and the path falls in the range of
  1.4 to 3.7 at a height of 0.01 solar radii. Additionally, we roughly
  estimated the distribution of the fast magnetosonic speed between the
  propagating path and sidewalls in an event on 1997 November 3, and
  found a relatively low-fast magnetosonic speed in the path. We also
  found that the propagating direction of Moreton waves coincided with
  the direction of filament eruption in a few well-observed events. This
  favors an interpretation of the ``Piston'' model, although further
  studies are necessary for any definitive conclusion.

Title: Imaging Observations of Coronal Magnetic Field by Nobeyama
    Radioheliograph
Authors: Shibasaki, K.; Narukage, N.; Yoshimura, K.
Bibcode: 2011ASPC..437..433S
Altcode:
  Coronal magnetic field in a post flare arcade of loops above the solar
  limb is mapped by the Nobeyama Radioheliograph. Post flare loops are
  filled with hot and dense plasma threaded by magnetic field. Thermal
  free-free microwave emission from these plasma is bright enough to
  carefully measure circular polarization degree. As circular polarization
  is the result of gyration of electrons around magnetic field, inversion
  of circular polarization degree to magnetic field strength is simple. We
  successfully measured the circular polarization degree distribution
  at 17 GHz and got a magnetic field map in a post flare arcade of loops
  above the solar limb.

Title: A Sounding Rocket Experiment for Spectropolarimetric
    Observations with the Ly<SUB>α</SUB> Line at 121.6 nm (CLASP)
Authors: Ishikawa, R.; Bando, T.; Fujimura, D.; Hara, H.; Kano,
   R.; Kobiki, T.; Narukage, N.; Tsuneta, S.; Ueda, K.; Wantanabe,
   H.; Kobayashi, K.; Trujillo Bueno, J.; Manso Sainz, R.; Stepan, J.;
   de Pontieu, B.; Carlsson, M.; Casini, R.
Bibcode: 2011ASPC..437..287I
Altcode:
  A team consisting of Japan, USA, Spain, and Norway is developing a
  high-throughput Chromospheric Lyman-Alpha SpectroPolarimeter (CLASP),
  which is proposed to fly with a NASA sounding rocket in 2014. CLASP will
  explore the magnetism of the upper solar chromosphere and transition
  region via the Hanle effect of the Ly<SUB>α</SUB> line for the first
  time. This experiment requires spectropolarimetric observations with
  high polarimetric sensitivity (∼0.1%) and wavelength resolution
  (0.1 Å). The final spatial resolution (slit width) is being discussed
  taking into account the required high signal-to-noise ratio. We have
  demonstrated the performance of the Ly<SUB>α</SUB> polarimeter by
  extensively using the Ultraviolet Synchrotron ORbital Radiation Facility
  (UVSOR) at the Institute for Molecular Sciences. In this contribution,
  we report these measurements at UVSOR together with the current status
  of the CLASP project.

Title: Coronal-Temperature-Diagnostic Capability of the Hinode/
    X-Ray Telescope Based on Self-Consistent Calibration
Authors: Narukage, N.; Sakao, T.; Kano, R.; Hara, H.; Shimojo, M.;
   Bando, T.; Urayama, F.; DeLuca, E.; Golub, L.; Weber, M.; Grigis,
   P.; Cirtain, J.; Tsuneta, S.
Bibcode: 2011SoPh..269..169N
Altcode: 2010arXiv1011.2867N; 2011SoPh..tmp....1N
  The X-Ray Telescope (XRT) onboard the Hinode satellite is an X-ray
  imager that observes the solar corona with unprecedentedly high angular
  resolution (consistent with its 1″ pixel size). XRT has nine X-ray
  analysis filters with different temperature responses. One of the most
  significant scientific features of this telescope is its capability
  of diagnosing coronal temperatures from less than 1 MK to more than
  10 MK, which has never been accomplished before. To make full use
  of this capability, accurate calibration of the coronal temperature
  response of XRT is indispensable and is presented in this article. The
  effect of on-orbit contamination is also taken into account in the
  calibration. On the basis of our calibration results, we review the
  coronal-temperature-diagnostic capability of XRT.

Title: A New View of the Sun with Hinode Mission
Authors: Sakao, Taro; Tsuneta, Saku; Shimojo, Masumi; Narukage,
   Noriyuki; Kano, Ryouhei; Obara, Takahiro; Watari, Shinichi; Hinode Team
Bibcode: 2009TrSpT...7Tr215S
Altcode:
  We present highlights of observations of the Sun with Japanese Hinode
  mission launched by JAXA in September 2006. The scientific objective
  of Hinode mission is to observe, in an unprecedented detail, a wide
  variety of plasma activities in the Sun's corona together with magnetic
  activities on the photosphere and in the chromosphere, utilizing a suite
  of three state-of-the-art telescopes; Solar Optical Telescope (SOT),
  X-Ray Telescope (XRT), and EUV Imaging Spectrometer (EIS). Since the
  beginning of the observations late in October 2006, Hinode has been
  providing ample information on activities of magnetized plasmas in the
  solar atmosphere some of which are totally new to us. In this article,
  we present an overview of the Hinode mission as well as some highlights
  of the observations.

Title: Plasma Outflows in the Corona as Observed With Hinode XRT
Authors: Sakao, T.; Kano, R.; Narukage, N.; Deluca, E. E.; Grigis, P.
Bibcode: 2008AGUFMSH41B1624S
Altcode:
  We present imaging observations of plasma outflows in the solar corona
  made with X-Ray Telescope (XRT) aboard Hinode satellite. The XRT employs
  a back-illuminated CCD as the focal-plane imaging device which enables
  us, together with an optimized set of analysis filters, to investigate,
  for the first time, dynamic behavior of relatively cool (1-2 MK, say)
  plasmas in the corona. The XRT revealed a clear pattern of continuous
  outflow of plasmas from the edge of an active region NOAA AR 10942 right
  adjacent to a coronal hole. Plasmas of temperature ~1 MK flowed out
  with a sub-sonic velocity of typically ~140 km/s along magnetic field
  lines that are most likely open towards the interplanetary space. These
  outflowing plasmas may constitute a fraction of the (slow) solar
  wind. In addition to this discovery, the XRT has so far identified
  rich patterns of continuous outflows including those from coronal
  hole boundaries and along fan-like field lines rooted inside coronal
  holes. XRT observations of such plasma outflows in the corona are
  presented and their possible implications to the solar wind discussed.

Title: The Thermal Structures of Solar Corona Revealed with Hinode/XRT
Authors: Narukage, N.; Sakao, T.; Kano, R.
Bibcode: 2008AGUFMSH52A..03N
Altcode:
  The solar corona has a wide temperature range from less than 1MK
  (1,000,000K) to more than 10MK. The X-ray telescope (XRT) on board
  the Hinode satellite has 9 X-ray analysis filters with different
  temperature responses making it possible to detect both cool and
  hot coronal plasmas. Using the data observed with this telescope,
  we successfully derived the coronal temperature and emission measure
  around the whole sun, i.e., for not only active regions but also quiet
  regions and coronal holes. We also found that coronal structures are
  nicely classified using the temperature and emission measure. And the
  coronal structures were found to depend on the length of structure
  and the heating flux. Furthermore, we calculated the coronal potential
  magnetic field using the photospheric magnetic field. To compare the
  heating flux estimated with coronal temperature and the calculated
  coronal magnetic field might be the great clue to solving the big
  coronal heating question: why does the hot 1MK corona stably exist
  above the cool 6,000K solar surface? In this talk, we will show some
  results of our latest studies about the coronal thermal structures.

Title: Observations and analysis of the April 9, 2008 CME using
    STEREO, Hinode TRACE and SoHO data
Authors: Reeves, K. K.; Patsourakos, S.; Stenborg, G.; Miralles, M.;
   Deluca, E.; Forbes, T.; Golub, L.; Kasper, J.; Landi, E.; McKenzie,
   D.; Narukage, N.; Raymond, J.; Savage, S.; Su, Y.; van Ballegooijen,
   A.; Vourlidas, A.; Webb, D.
Bibcode: 2008AGUFMSH12A..04R
Altcode:
  On April 9, 2008 a CME originating from an active region behind the limb
  was well-observed by STEREO, Hinode, TRACE and SoHO. Several interesting
  features connected to this eruption were observed. (1) The interaction
  of the CME with open field lines from a nearby coronal hole appeared
  to cause an abrupt change in the direction of the CME ejecta. (2) The
  prominence material was heated, as evidenced by a change from absorption
  to emission in the EUV wavelengths. (3) Because the active region was
  behind the limb, the X-Ray Telescope on Hinode was able to take long
  enough exposure times to observe a faint current- sheet like structure,
  and it was able to monitor the dynamics of the plasma surrounding this
  structure. This event is also being studied in the context of activity
  that occurred during the Whole Heliosphere Interval (WHI).

Title: Strongly Blueshifted Phenomena Observed with Hinode EIS in
    the 2006 December 13 Solar Flare
Authors: Asai, Ayumi; Hara, Hirohisa; Watanabe, Tetsuya; Imada,
   Shinsuke; Sakao, Taro; Narukage, Noriyuki; Culhane, J. L.; Doschek,
   G. A.
Bibcode: 2008ApJ...685..622A
Altcode: 2008arXiv0805.4468A
  We present a detailed examination of strongly blueshifted emission
  lines observed with the EUV Imaging Spectrometer on board the Hinode
  satellite. We found two kinds of blueshifted phenomenon associated
  with the X3.4 flare that occurred on 2006 December 13. One was related
  to a plasmoid ejection seen in soft X-rays. It was very bright in all
  the lines used for the observations. The other was associated with the
  faint arc-shaped ejection seen in soft X-rays. The soft X-ray ejection
  is thought to be a magnetohydrodynamic (MHD) fast-mode shock wave. This
  is therefore the first spectroscopic observation of an MHD fast-mode
  shock wave associated with a flare.

Title: Three Successive and Interacting Shock Waves Generated by a
    Solar Flare
Authors: Narukage, Noriyuki; Ishii, Takako T.; Nagata, Shin'ichi;
   UeNo, Satoru; Kitai, Reizaburo; Kurokawa, Hiroki; Akioka, Maki;
   Shibata, Kazunari
Bibcode: 2008ApJ...684L..45N
Altcode:
  We discovered three successive Moreton waves generated by a single solar
  flare on 2005 August 3. Although this flare was not special in magnitude
  or configuration, Moreton waves (shock waves) successively occurred
  three times. Multiple shock waves generated during a single flare have
  not been reported before. Furthermore, the faster second-generated
  Moreton wave caught up and merged with the slower first-generated
  one. This is the first report of shock-shock interaction associated with
  a solar flare. The shock-plasma interaction was also detected. When
  the third-generated Moreton wave passed through an erupting filament,
  the filament was accelerated by the Moreton wave. In this event,
  filaments also erupted three times. On the basis of this observation,
  we consider that filament eruption is indispensable to the generation
  of Moreton waves.

Title: Hinode/XRT Diagnostics of Loop Thermal Structure
Authors: Reale, F.; Parenti, S.; Reeves, K. K.; Weber, M.; Bobra,
   M. G.; Barbera, M.; Kano, R.; Narukage, N.; Shimojo, M.; Sakao, T.;
   Peres, G.; Golub, L.
Bibcode: 2008ASPC..397...50R
Altcode:
  We investigate possible diagnostics of the thermal structure of coronal
  loops from Hinode/XRT observations made with several filters. We
  consider the observation of an active region with five filters. We
  study various possible combinations of filter data to optimize for
  sensitivity to thermal structure and for signal enhancement.

Title: Vertical Temperature Structures of the Solar Corona Derived
    with the Hinode X-Ray Telescope
Authors: Kano, Ryouhei; Sakao, Taro; Narukage, Noriyuki; Tsuneta,
   Saku; Kotoku, Jun'ichi; Bando, Takamasa; Deluca, Edward; Lundquist,
   Loraine; Golub, Leon; Hara, Hirohisa; Matsuzaki, Keiichi; Shimojo,
   Masumi; Shibasaki, Kiyoto; Shimizu, Toshifumi; Nakatani, Ichiro
Bibcode: 2008PASJ...60..827K
Altcode:
  We obtained temperature structures in faint coronal features
  above and near the solar limb with the X-Ray Telescope aboard the
  Hinode satellite by accurately correcting the scattered X-rays
  from surrounding bright regions with occulted images during
  the solar eclipses. Our analysis yields a polar coronal hole
  temperature of about 1.0MK and an emission measure in the range of
  10<SUP>25.5</SUP>-10<SUP>26.0</SUP>cm<SUP>-5</SUP>. In addition,
  our methods allow us to measure the temperature and emission
  measure of two distinct quiet-Sun structures: radial (plume-like)
  structures near the boundary of the coronal-hole and diffuse quiet
  Sun regions at mid-latitudes. The radial structures appear to have
  increasing temperature with height during the first 100Mm, and
  constant temperatures above 100Mm. For the diffuse quiet-Sun region
  the temperatures are the highest just above the limb, and appear
  to decrease with height. These differences may be due to different
  magnetic configurations.

Title: Molecular Contamination Assessments on
    &lt;i&gt;Hinode&lt;/i&gt; X-Ray Telescope
Authors: Urayama, Fumitaka; Bando, Takamasa; Kano, Ryouhei; Hara,
   Hirohisa; Narukage, Noriyuki; Sakao, Taro
Bibcode: 2008JSASS..56..536U
Altcode:
  The &lt;i&gt;Hinode&lt;/i&gt; (Solar-B) was launched by M-V rocket on 22
  September 2006 UT. The telemetry data of the &lt;i&gt;Hinode&lt;/i&gt;
  X-ray Telescope (XRT) showed that the X-ray count rate detected with
  the XRT had decreased rapidly since the operational heaters on the
  XRT telescope tube were turned on. This is attributed to the fact that
  molecular contaminants accumulated onto the CCD with the temperature
  of -60ºC resulting in the degradation of the XRT sensitivity. We baked
  the CCD at the temperature of 35ºC in order to remove the contaminants
  from the CCD surface. However many contaminant spots appeared on the
  surface. We found that major contaminant source existed in the telescope
  tube, and identified the contaminants as diethylhexyl phthalate (DEHP)
  or DEHP-like organics. The mechanisms to yield the contaminant spots
  were discussed.

Title: Relation between coronal temperature and magnetic field
Authors: Narukage, Noriyuki; Kano, Ryouhei; Shiota, Daiko; Sakao, Taro
Bibcode: 2008cosp...37.2184N
Altcode: 2008cosp.meet.2184N
  The solar corona has a wide temperature range from less than 1MK to
  more than 10MK. The X-ray telescope (XRT) on board Hinode satellite
  has 9 X-ray analysis filters to observe the almost of whole coronal
  plasma. Using the data observed with this telescope, we successfully
  derived the coronal temperature around the whole sun. We found that
  coronal structures are nicely classified using the temperature and
  emission measure. The coronal structures were found to depend on the
  length of structure and the heating flux. Furthermore, we calculated
  the coronal potential magnetic field in high spatial resolution using
  the photospheric magnetic field observed with SOHO/MDI. To compare the
  heating flux estimated with coronal temperature and the calculated
  coronal magnetic field might be the great clue to solving the big
  coronal heating question.

Title: Cross calibration of soft X-ray telescopes between Hinode/XRT
    and GOES13/SXI
Authors: Narukage, N.; Sakao, T.; Kano, R.; Shimojo, M.; Cirtain,
   J.; Deluca, E.; Nitta, N.; Lemen, J.
Bibcode: 2007AGUFMSH53A1050N
Altcode:
  The X-Ray Telescope (XRT) aboard Hinode satellite is a grazing
  incidence telescope to observe all the coronal features with a wide
  temperature range from less than 1MK to more than 10MK. And the XRT
  has 9 X-ray analysis filters which are optimized to observed the
  almost whole coronal plasma and to derived the coronal temperature
  distribution. Meanwhile, the GOES13 satellite carries a Solar X-ray
  Imager (SXI) to monitor the solar X-rays. The SXI is also a grazing
  incidence telescope and has 7 X-ray filters. The XRT and SXI are
  similar telescopes to observe the dynamic solar corona. On 24 Nov 2006,
  the XRT and SXI-team performed the simultaneous observation for the
  cross calibration between XRT and SXI. In this study, we analyzed
  this data set and checked the actual characteristics of each X-ray
  analysis filter.

Title: Slipping Magnetic Reconnection in Coronal Loops
Authors: Aulanier, Guillaume; Golub, Leon; DeLuca, Edward E.; Cirtain,
   Jonathan W.; Kano, Ryouhei; Lundquist, Loraine L.; Narukage, Noriyuki;
   Sakao, Taro; Weber, Mark A.
Bibcode: 2007Sci...318.1588A
Altcode:
  Magnetic reconnection of solar coronal loops is the main process that
  causes solar flares and possibly coronal heating. In the standard
  model, magnetic field lines break and reconnect instantaneously at
  places where the field mapping is discontinuous. However, another mode
  may operate where the magnetic field mapping is continuous but shows
  steep gradients: The field lines may slip across each other. Soft
  x-ray observations of fast bidirectional motions of coronal loops,
  observed by the Hinode spacecraft, support the existence of this
  slipping magnetic reconnection regime in the Sun’s corona. This
  basic process should be considered when interpreting reconnection,
  both on the Sun and in laboratory-based plasma experiments.

Title: Evidence for Alfvén Waves in Solar X-ray Jets
Authors: Cirtain, J. W.; Golub, L.; Lundquist, L.; van Ballegooijen,
   A.; Savcheva, A.; Shimojo, M.; DeLuca, E.; Tsuneta, S.; Sakao, T.;
   Reeves, K.; Weber, M.; Kano, R.; Narukage, N.; Shibasaki, K.
Bibcode: 2007Sci...318.1580C
Altcode:
  Coronal magnetic fields are dynamic, and field lines may misalign,
  reassemble, and release energy by means of magnetic reconnection. Giant
  releases may generate solar flares and coronal mass ejections and,
  on a smaller scale, produce x-ray jets. Hinode observations of polar
  coronal holes reveal that x-ray jets have two distinct velocities:
  one near the Alfvén speed (~800 kilometers per second) and another
  near the sound speed (200 kilometers per second). Many more jets were
  seen than have been reported previously; we detected an average of
  10 events per hour up to these speeds, whereas previous observations
  documented only a handful per day with lower average speeds of 200
  kilometers per second. The x-ray jets are about 2 × 10<SUP>3</SUP> to
  2 × 10<SUP>4</SUP> kilometers wide and 1 × 10<SUP>5</SUP> kilometers
  long and last from 100 to 2500 seconds. The large number of events,
  coupled with the high velocities of the apparent outflows, indicates
  that the jets may contribute to the high-speed solar wind.

Title: Continuous Plasma Outflows from the Edge of a Solar Active
    Region as a Possible Source of Solar Wind
Authors: Sakao, Taro; Kano, Ryouhei; Narukage, Noriyuki; Kotoku,
   Jun'ichi; Bando, Takamasa; DeLuca, Edward E.; Lundquist, Loraine L.;
   Tsuneta, Saku; Harra, Louise K.; Katsukawa, Yukio; Kubo, Masahito;
   Hara, Hirohisa; Matsuzaki, Keiichi; Shimojo, Masumi; Bookbinder, Jay
   A.; Golub, Leon; Korreck, Kelly E.; Su, Yingna; Shibasaki, Kiyoto;
   Shimizu, Toshifumi; Nakatani, Ichiro
Bibcode: 2007Sci...318.1585S
Altcode:
  The Sun continuously expels a huge amount of ionized material into
  interplanetary space as the solar wind. Despite its influence on the
  heliospheric environment, the origin of the solar wind has yet to
  be well identified. In this paper, we report Hinode X-ray Telescope
  observations of a solar active region. At the edge of the active region,
  located adjacent to a coronal hole, a pattern of continuous outflow of
  soft-x-ray emitting plasmas was identified emanating along apparently
  open magnetic field lines and into the upper corona. Estimates of
  temperature and density for the outflowing plasmas suggest a mass
  loss rate that amounts to ~1/4 of the total mass loss rate of the
  solar wind. These outflows may be indicative of one of the solar wind
  sources at the Sun.

Title: Fine Thermal Structure of a Coronal Active Region
Authors: Reale, Fabio; Parenti, Susanna; Reeves, Kathy K.; Weber,
   Mark; Bobra, Monica G.; Barbera, Marco; Kano, Ryouhei; Narukage,
   Noriyuki; Shimojo, Masumi; Sakao, Taro; Peres, Giovanni; Golub, Leon
Bibcode: 2007Sci...318.1582R
Altcode:
  The determination of the fine thermal structure of the solar corona is
  fundamental to constraining the coronal heating mechanisms. The Hinode
  X-ray Telescope collected images of the solar corona in different
  passbands, thus providing temperature diagnostics through energy
  ratios. By combining different filters to optimize the signal-to-noise
  ratio, we observed a coronal active region in five filters, revealing
  a highly thermally structured corona: very fine structures in the
  core of the region and on a larger scale further away. We observed
  continuous thermal distribution along the coronal loops, as well as
  entangled structures, and variations of thermal structuring along the
  line of sight.

Title: A Study of Polar Jet Parameters Based on Hinode XRT
    Observations
Authors: Savcheva, Antonia; Cirtain, Jonathan; Deluca, Edward E.;
   Lundquist, Loraine L.; Golub, Leon; Weber, Mark; Shimojo, Masumi;
   Shibasaki, Kiyoto; Sakao, Taro; Narukage, Noriyuki; Tsuneta, Saku;
   Kano, Ryouhei
Bibcode: 2007PASJ...59S.771S
Altcode:
  Hinode/SOHO campaign 7197 is the most extensive study of polar jet
  formation and evolution from within both the north and south polar
  coronal holes so far. For the first time, this study showed that the
  appearance of X-ray jets in the solar coronal holes occurs at very high
  frequency - about 60 jets d<SUP>-1</SUP> on average. Using observations
  collected by the X-Ray Telescope on Hinode, a number of physical
  parameters from a large sample of jets were statistically studied. We
  measured the apparent outward velocity, the height, the width and
  the lifetime of the jets. In our sample, all of these parameters show
  peaked distributions with maxima at 160kms<SUP>-1</SUP> for the outward
  velocity, 5 × 10<SUP>4</SUP> km for the height, 8 × 10<SUP>3</SUP>
  km for the width, and about 10min for the lifetime of the jets. We
  also present the first statistical study of jet transverse motions,
  which obtained transverse velocities of 0-35kms<SUP>-1</SUP>. These
  values were obtained on the basis of a larger (in terms of frequency)
  and better sampled set of events than what was previously statistically
  studied (Shimojo et al. 1996, PASJ, 48, 123). The results were made
  possible by the unique characteristics of XRT. We describe the methods
  used to determine the characteristics and set some future goals. We
  also show that despite some possible selection effects, jets preferably
  occur inside the polar coronal holes.

Title: Hinode Observations of the Onset Stage of a Solar Filament
    Eruption
Authors: Sterling, Alphonse C.; Moore, Ronald L.; Berger, Thomas
   E.; Bobra, Monica; Davis, John M.; Jibben, Patricia; Kano, Ryohei;
   Lundquist, Loraine L.; Myers, D.; Narukage, Noriyuki; Sakao, Taro;
   Shibasaki, Kiyoto; Shine, Richard A.; Tarbell, Theodore D.; Weber, Mark
Bibcode: 2007PASJ...59S.823S
Altcode:
  We used Hinode X-Ray Telescope (XRT) and Solar Optical Telescope (SOT)
  filtergraph (FG) Stokes-V magnetogram observations, to study the
  early onset of a solar eruption that includes an erupting filament
  that we observe in TRACE EUV images. The filament undergoes a slow
  rise for at least 20min prior to its fast eruption and strong soft
  X-ray (SXR) flaring; such slow rises have been previously reported,
  and the new Hinode data elucidate the physical processes occurring
  during this period. XRT images show that during the slow-rise phase,
  an SXR sigmoid forms from apparent reconnection low in the sheared core
  field traced by the filament, and there is a low-level intensity peak
  in both EUV and SXRs during the slow rise. MDI and SOT FG Stokes-V
  magnetograms show that the pre-eruption filament is along a neutral
  line between opposing-polarity enhanced network cells, and the SOT
  magnetograms show that these opposing fields are flowing together
  and canceling for at least six hours prior to eruption. From the MDI
  data we measured the canceling network fields to be ∼ 40G, and we
  estimated that ∼ 10<SUP>19</SUP> Mx of flux canceled during the
  five hours prior to eruption; this is only ∼ 5% of the total flux
  spanned by the eruption and flare, but apparently its tether-cutting
  cancellation was enough to destabilize the sigmoid field holding the
  filament and resulted in that field's eruption.

Title: Fine Structures of Solar X-Ray Jets Observed with the X-Ray
    Telescope aboard Hinode
Authors: Shimojo, Masumi; Narukage, Noriyuki; Kano, Ryohei; Sakao,
   Taro; Tsuneta, Saku; Shibasaki, Kiyoto; Cirtain, Jonathan W.;
   Lundquist, Loraine L.; Reeves, Katherine K.; Savcheva, Antonia
Bibcode: 2007PASJ...59S.745S
Altcode:
  The X-Ray Telescope (XRT) aboard Hinode has revealed the fine structure
  of solar X-ray jets. One of the fine structures observed by XRT is an
  expanding loop. The loop appeared near the footpoint of the jet when
  footpoint brightening was observed. Additionally, we have found that the
  X-ray jets began just after the expanding loop ``breaks''. Other fine
  structures discovered by XRT are thread-like features along the axis
  of the jets. XRT has shown that these thread structures compose the
  cross-section of jets. The fine structures and their motions strongly
  support an X-ray jet model based on magnetic reconnection, and also
  suggest that we must consider the three-dimensional configuration of the
  magnetic field to understand the jet phenomenon. We also investigated
  the reverse jet associated with the X-ray jet in the quiet Sun, and
  propose that the reverse jet is produced by heat conduction, or a MHD
  wave subsequent to the main jet.

Title: Evolution of the Sheared Magnetic Fields of Two X-Class Flares
    Observed by Hinode/XRT
Authors: Su, Yingna; Golub, Leon; van Ballegooijen, Adriaan; Deluca,
   Edward E.; Reeves, Kathy K.; Sakao, Taro; Kano, Ryouhei; Narukage,
   Noriyuki; Shibasaki Kiyoto
Bibcode: 2007PASJ...59S.785S
Altcode:
  We present multi-wavelength observations of the evolution of the sheared
  magnetic fields in NOAA Active Region 10930, where two X-class flares
  occurred on 2006 December 13 and December 14, respectively. Observations
  made with the X-ray Telescope (XRT) and the Solar Optical Telescope
  (SOT) aboard Hinode suggest that the gradual formation of the sheared
  magnetic fields in this active region is caused by the rotation and
  west-to-east motion of an emerging sunspot. In the pre-flare phase
  of the two flares, XRT shows several highly sheared X-ray loops in
  the core field region, corresponding to a filament seen in the TRACE
  EUV observations. XRT observations also show that part of the sheared
  core field erupted, and another part of the sheared core field stayed
  behind during the flares, which may explain why a large part of the
  filament is still seen by TRACE after the flare. About 2-3 hours after
  the peak of each flare, the core field becomes visible in XRT again,
  and shows a highly sheared inner and less-sheared outer structure. We
  also find that the post-flare core field is clearly less sheared than
  the pre-flare core field, which is consistent with the idea that the
  energy released during the flares is stored in the highly sheared
  fields prior to the flare.

Title: An On-Orbit Determination of the On-Axis Point Spread Function
    of the Hinode X-Ray Telescope
Authors: Weber, Mark; Deluca, Edward E.; Golub, Leon; Cirtain,
   Jonathan; Kano, Ryouhei; Sakao, Taro; Shibasaki, Kiyoto; Narukage,
   Noriyuki
Bibcode: 2007PASJ...59S.853W
Altcode:
  The Hinode X-ray Telescope provides unprecedented observations of
  the solar corona in X-rays, due in part to its fine resolution. The
  X-ray point spread function (PSF) was measured before launch at the
  NASA X-ray Calibration Facility to have a FWHM of 0.8''. This paper
  describes the work to verify the PSF measurements using on-orbit
  observations of planetary transits and solar eclipses. Analysis of a
  Mercury transit gives a PSF FWHM = 1.0" ± 0.12".

Title: Plans to Observe Flare-Associated Waves with Solar-B
Authors: Narukage, N.
Bibcode: 2007ASPC..369..205N
Altcode:
  The textit{Solar-B} satellite has three scientific instruments: the
  Solar Optical Telescope (SOT), the X-ray Telescope (XRT) and the EUV
  Imaging Spectrograph (EIS). We expect SOT, XRT, and EIS to detect
  the origin of Moreton waves, coronal X-ray waves, and line-of-sight
  velocity of waves, respectively. In preparation for Solar-B, we examine
  the detectable possibility of waves with these telescopes and suggest
  methods for observation.

Title: The Dynamics Of Fine Structures In Solar X-ray Jets
Authors: Shimojo, Masumi; Narukage, N.; Kano, R.; Sakao, T.; Tsuneta,
   T.; Cirtain, J. W.; Lundquist, L. L.; Deluca, E. E.; Golub, L.
Bibcode: 2007AAS...210.9422S
Altcode: 2007BAAS...39Q.221S
  The X-ray telescope(XRT) aboard HINODE satellite has the great
  spatial/time resolution in X-ray range. And, the observations using
  XRT have revealed the fine structures of solar corona. From the
  observations, we found the fine thread structures in the X-ray jets
  and the structures move dynamically like wave. We also found that some
  X-ray jets start just after small loop expansion in the footpoint
  brightening. The observation results suggest that the reconnection
  process X-ray jets is very similar to that in large flares.

Title: Hinode Data Calibration For Precise Image Co-alignment:
    XRT vs. SOT
Authors: Shimizu, Toshifumi; DeLuca, E. E.; Lundquist, L.; Sakao,
   T.; Kubo, M.; Narukage, N.; Kano, R.; Katsukawa, Y.; Ichimoto, K.;
   Suematsu, Y.; Tsuneta, S.; Tarbell, T.; Shine, D.; Hinode Team
Bibcode: 2007AAS...210.9417S
Altcode: 2007BAAS...39Q.220S
  From late October in 2006, Hinode solar optical telescope (SOT) has
  started to produce series of 0.2-0.3 arcsec visible-light images,
  revealing dynamical behaviors of solar magnetic fields on the
  solar surface. Simultaneously, Hinode X-ray telescope (XRT) has been
  providing 1 arcsec resolution X-ray images of the solar corona, giving
  the location of heating and dynamics occuring in the corona. Precise
  image co-alignment of SOT data on XRT data with sub-arcsec accuracy is
  required to provide new information regarding connecting the corona to
  the photosphere. This presentation will give an introduction of Hinode
  between-telescopes' image co-alignment to SPD participants. For active
  region observations with sunspots, sunspots can be used as fiducial to
  co-align the data from the two telescopes each other. Satellite jitter
  in order of 1 arcsec or less is included in the series of XRT data,
  whereas image stabilization system (correlation tracker) removes the
  satellite jitter from the series of SOT images. Telescope pointings show
  orbital variation in order of a few arcsec, which can be well predicted
  from Hinode orbit information. Modeling co-alignment is under study
  and it is the only precise method for quiet Sun and limb observations.

Title: Coronal Temperature Diagnostics With Hinode X-ray Telescope
Authors: Narukage, Noriyuki; Sakao, T.; Kano, R.; Shimojo, M.; Tsuneta,
   S.; Kosugi, T.; Deluca, E. E.; Golub, L.; Weber, M.; Cirtain, J.;
   Japan-US X-Ray Telescope Team
Bibcode: 2007AAS...210.6304N
Altcode: 2007BAAS...39..172N
  An X-ray telescope (XRT) on board HINODE satellite observes the Sun
  in X-rays with high special resolution (1arcsec 730km on solar the
  disk). This telescope has 9 X-ray filters with different temperature
  responses. Using these filters, the XRT can detect the coronal
  plasma with a wide temperature range from less than 1MK to more
  than 10MK. Moreover, based on observations with more than 2 filters,
  we can estimate the coronal temperature. In this paper, we use the
  filter ratio method for coronal temperature diagnostics. Using this
  method, we can easily estimate the averaged temperature of the coronal
  plasma along the line-of-sight. This method has been used frequently
  in the past, but the high quality XRT data give us temperature maps
  with unprecedented accuracy and resolution. The XRT usually takes
  the full Sun images with 2 kinds of filters 4 times a day. Using this
  data and filter ratio method, we can obtain full Sun temperature maps
  with high special resolution. In our analysis, we can derive reliable
  temperatures not only in active regions but also in quiet regions and
  coronal holes. This map can be created with the data set of one synoptic
  observation. This means that we can obtain 4 maps a day. The result is
  a full Sun temperature movie that gives us an unprecedented view of the
  time evolution of solar temperature. In this meeting, we will show the
  full Sun temperature movie and our coronal temperature analysis results.

Title: Continuous Upflow of Plasmas at the Edge of an Active Region
    as Revealed by the X-ray Telescope (XRT) aboard Hinode
Authors: Sakao, Taro; Kano, R.; Narukage, N.; Kotoku, J.; Bando, T.;
   DeLuca, E. E.; Lundquist, L. L.; Golub, L.; Kubo, M.; Katsukawa, Y.;
   Tsuneta, S.; Hara, H.; Matsuzaki, K.; Shimojo, M.; Shibasaki, K.;
   Shimizu, T.; Nakatani, I.
Bibcode: 2007AAS...210.7205S
Altcode: 2007BAAS...39Q.179S
  We present X-ray imaging observations with Hinode X-Ray Telescope (XRT)
  of an active region NOAA AR 10942 made in the period of 20-22 February
  2007. A prominent feature that drew our particular attention is that
  there revealed continuous upflow of soft-X-ray-emitting plasmas along
  apparently-open field lines towards the outer corona emanating from the
  edge of the active region. <P />The field lines are originated from
  an ensamble of small spots of following polarity, and are located at
  a border between the active region and an adjacent equatorial coronal
  hole(s) located to the east. The upflow was observed to be continuous
  throughout the three days of observation intervals with projected
  velocity of 140 km/s, accompanied with undulating motion of the field
  lines. <P />We assert that these upflowing plasmas would be a possible
  source of slow solar wind material, which supports a foresighted
  notion which grew out of interplanetary scintillation observations
  that slow solar wind most likely has its origin in the vicinity of
  active regions with large flux expansion (Kojima et al. 1999). <P />A
  preliminaty analysis indicates that the temperature of the upflowing
  material near the base of the field lines is 1.3 MK with number density
  of 2 × 10<SUP>9 </SUP>/cm<SUP>3</SUP>. Assuming that all the material
  is to escape to the interplanetary space, this leads to a mass loss
  rate of 2 × 10<SUP>11</SUP> g/s which amounts to a good fraction of
  the total mass loss rate for solar wind. It is noteworthy that, even
  apart from this unique upflow, we see continuous (up)flows of plasmas
  anywhere around (surrounding) the active region. <P />Details of the
  upflow will be presented and their possible implication to slow solar
  wind discussed.

Title: Structure and Coronal Activity around Filament Channels
    Observed with Hinode XRT And TRACE
Authors: Lundquist, Loraine L.; van Ballegooijen, A. A.; Reeves,
   K. K.; Sakao, T.; DeLuca, E. E.; Narukage, N.; Kano, R.
Bibcode: 2007AAS...210.9427L
Altcode: 2007BAAS...39..221L
  The combination of multi-wavelength, high resolution, high cadence
  data from the Hinode X-Ray Telescope (XRT) and the Transition Region
  And Coronal Explorer (TRACE) give an unprecedented view of solar
  active region dynamics and coronal topology. We focus on examples of
  filament structures observed by TRACE and XRT in December 2006 and
  February 2007. Co-alignment of observations in these two instruments
  yields a striking picture of the coronal structures, with loops lying
  both along and above the filament. Overlying loops exhibit remarkable
  dynamics while the filament lies dormant, and numerous x-point and
  triple-leg structures undergo repeated brightenings. We also employ
  magnetic field data from SOT and from SOLIS to compare a non-linear
  force-free model of the coronal magnetic field with the observed loops.

Title: Temperature Structures Above Coronal Hole and Quiet Sun
Authors: Kano, Ryouhei; Sakao, T.; Narukage, N.; Kotoku, J.; Bando,
   T.; DeLuca, E. E.; Lundquist, L.; Golub, L.; Tsuneta, S.; Hara, H.;
   Shibasaki, K.; Shimojo, M.
Bibcode: 2007AAS...210.9436K
Altcode: 2007BAAS...39..223K
  The X-ray Telescope (XRT) on board Hinode satelite has the capability
  to derive the temperature structure in the solar corona. We present
  the hieght dependence of the temperature above the limb. Because X-ray
  intensity above the limb is so faint, it is important to estimate the
  scattered light from disk corona. The eclipses happened on February 17
  and March 19 in 2007 at Hinode orbit. On February 17, we took X-ray
  images above the south polar coronal hole, while Moon passed it. On
  March 19, we took the data for quiet Sun in the same way. <P />We
  can estimated the scattered light from the eclipse data, and derived
  the scatter-free X-ray images above the solar limb. In this meeting,
  we will present the temperatures above coronal hole and quiet Sun,
  based on the eclipse data.

Title: Magnetic activity and the solar corona: first results from
    the Hinode satellite .
Authors: Reale, Fabio; Parenti, Susanna; Reeves, Kathy K.; Weber,
   Mark; Bobra, Monica G.; Barbera, Marco; Kano, Ryohei; Narukage,
   Noriyuki; Shimojo, Masumi; Sakao, Taro; Peres, Giovanni; Golub, Leon
Bibcode: 2007MmSAI..78..591R
Altcode:
  The structure, dynamics and evolution of the solar corona are governed
  by the magnetic field. In spite of significant progresses in our insight
  of the physics of the solar corona, several problems are still under
  debate, e.g. the role of impulsive events and waves in coronal heating,
  and the origin of eruptions, flares and CMEs. The Hinode mission has
  started on 22 september 2006 and aims at giving new answers to these
  questions. The satellite contains three main instruments, two high
  resolution telescopes, one in the optical and one in the X-ray band,
  and an EUV imaging spectrometer. On the Italian side, INAF/Osservatorio
  Astronomico di Palermo has contributed with the ground-calibration
  of the filters of the X-ray telescope. We present some preliminary
  mission results, with particular attention to the X-ray telescope data.

Title: Statistical Analysis of Reconnection Inflows in Solar Flares
    Observed with SOHO EIT
Authors: Narukage, Noriyuki; Shibata, Kazunari
Bibcode: 2006ApJ...637.1122N
Altcode:
  We report observations of reconnection inflows in extreme ultraviolet
  (EUV) Fe XII λ195 images with the Extreme Ultraviolet Imaging Telescope
  (EIT) on board the Solar and Heliospheric Observatory (SOHO). Yokoyama
  and colleagues reported the first example observed on 1999 March 18. We
  survey the EIT data from 1996 to 2000 and find six new inflow events. We
  measure the inflow velocity v<SUB>inflow</SUB> for each event and find
  that v<SUB>inflow</SUB> is about 2.6-38 km s<SUP>-1</SUP>. Furthermore,
  using the six EIT inflow events observed simultaneously with Yohkoh SXT
  (including the Yokoyama event), we calculate the reconnection rate as
  M<SUB>A</SUB>≡v<SUB>inflow</SUB>/v<SUB>A</SUB>=0.001-0.07. It is also
  found that the plasmoid ejection and/or coronal mass ejection (CME)
  are closely related to the inflow. The velocity of the CME exhibits
  a correlation with the inflow velocity.

Title: Magnetic Fields and Intensity Changes in Coronal Dimming
    Regions
Authors: Attrill, G. D. R.; Narukage, N.; Shibata, K.; Harra, L. K.
Bibcode: 2005ESASP.596E..11A
Altcode: 2005ccmf.confE..11A
  No abstract at ADS

Title: Observations of Flare-Associated Waves with SolarB
Authors: Narukage, N.; Shibata, K.
Bibcode: 2004ASPC..325..389N
Altcode:
  In Hα, a flare-associated chromospheric wave (called a Moreton
  wave) was discovered in 1960, and after that such waves are
  sometimes observed. Uchida (1968, 1974) identified the Moreton
  wave as the intersection of a coronal MHD fast-mode shock and the
  chromosphere. Recently, the Soft X-ray Telescope (SXT) on board Yohkoh
  observed coronal wave-like disturbances (X-ray waves). Narukage et
  al. (2002, 2004) showed two X-ray waves are MHD fast-mode shock,
  i.e. coronal counterparts of the Moreton waves. The SolarB has
  Solar Optical Telescope (SOT), X-Ray Telescope (XRT) and EUV Imaging
  Spectrometer (EIS) on board and will be launched in 2006. We expect
  SOT, XRT and EIS will detect chromospheric Moreton waves, coronal X-ray
  waves and line-of-sight velocity of waves, respectively. In preparation
  for SolarB, we examine the detectable possibility of waves with these
  telescopes and suggest methods for observation.

Title: Filament Oscillations and Moreton Waves Associated with
    EIT Waves
Authors: Okamoto, Takenori J.; Nakai, Hidekazu; Keiyama, Atsushi;
   Narukage, Noriyuki; UeNo, Satoru; Kitai, Reizaburo; Kurokawa, Hiroki;
   Shibata, Kazunari
Bibcode: 2004ApJ...608.1124O
Altcode:
  In this paper we compare EUV Imaging Telescope (EIT) waves with
  simultaneous phenomena seen in Hα in order to address the question
  of what an EIT wave is. We surveyed the events associated with solar
  flares larger than GOES M-class in 1999-2002. The Hα data are taken
  with the Flare-monitoring Telescope (FMT) at the Hida Observatory
  of Kyoto University. Among 14 simultaneous observations of EIT
  waves and Hα, 11 were found to have filament eruptions, three were
  associated with Moreton waves, and one was found to have only filament
  oscillations. This shows that we cannot see clear wave fronts in
  Hα even if EIT waves exist, but that it is possible to recognize
  invisible waves by means of filament oscillations. The nature of
  filament oscillations and Moreton waves associated with EIT waves is
  examined in detail, and it is found that the filament oscillations
  were caused by EIT waves.

Title: Moreton waves observed at Hida Observatory
Authors: Narukage, Noriyuki; Eto, Shigeru; Kadota, Miwako; Kitai,
   Reizaburo; Kurokawa, Hiroki; Shibata, Kazunari
Bibcode: 2004IAUS..223..367N
Altcode: 2005IAUS..223..367N
  Moreton waves are flare-associated waves observed to propagate across
  the solar disk in Halpha, especially in the wing of Halpha. The Flare
  Monitoring Telescope at Hida Observatory of Kyoto University observed
  12 events associated with flare waves (i.e., Moreton waves and/or
  filament oscillations) in Halpha from 1997 to 2002. We review our
  studies of Moreton waves based on these observations; relation between
  EIT wave and Moreton wave (Eto et al. 2002),simultaneous observation
  with X-ray wave (Narukage et al. 2002),three dimensional structure of
  flare-associated wave (Narukage et al. 2004),relation between Moreton
  waves and filament eruptions.

Title: Statistical analysis of reconnection inflows in solar flares
Authors: Narukage, N.; Shibata, K.
Bibcode: 2004cosp...35.3696N
Altcode: 2004cosp.meet.3696N
  Solar flare is an explosion on the solar surface and releases huge
  energy in a short time. It is widely believed that the energy
  is stored in magnetic field and the flare is caused by magnetic
  reconnection. Yohkoh, a Japanese solar X-ray satellite launched in 1991,
  discovered various evidence of the magnetic reconnection, e.g. cusp
  shaped loops, plasmoid ejections, and etc. The reconnection model
  has been established at least phenomenologically by Yohkoh. However,
  the inflow, which is predicted by the reconnection theory, has not been
  discovered, and it remains mystery. In 2000, Yokoyama et al. discovered
  such reconnection inflow in a solar flare observed with SOHO/EIT,
  but no other observation of reconnection inflow has been reported
  until now. The generality of inflow remains doubtful. We surveyed
  the reconnection inflow in the full Sun movies taken with SOHO/EIT
  and discovered 13 inflows. We measured the line-of-sight velocity of
  the inflows using SOHO/EIT images, the angle between magnetic neutral
  line and line-of-sight direction in the inflows using SOHO/MDI images,
  and the energy release rate of the flares associated with the inflows
  using Yohkoh/SXT images. Based on this results, we estimated some
  physical quantities of the inflows, e.g. the real inflow velocity and
  reconnection rate. This result is conclusive evidence of reconnection
  and the clue to the solution of flare mechanism.

Title: Relation between a Moreton Wave and an EIT Wave Observed on
    1997 November 4
Authors: Eto, Shigeru; Isobe, Hiroaki; Narukage, Noriyuki; Asai, Ayumi;
   Morimoto, Taro; Thompson, Barbara; Yashiro, Seiji; Wang, Tongjiang;
   Kitai, Reizaburo; Kurokawa, Hiroki; Shibata, Kazunari
Bibcode: 2002PASJ...54..481E
Altcode:
  We consider the relationship between two flare-associated waves,
  a chromospheric Moreton wave and a coronal EIT wave, based on an
  analysis of an X-class flare event in AR 8100 on 1997 November 4. A
  Moreton wave was observed in Hα + 0.8 Å, and Hα - 0.8 Å with the
  Flare-Monitoring Telescope (FMT) at the Hida Observatory. An EIT wave
  was observed in EUV with the Extreme ultraviolet Imaging Telescope
  (EIT) on board SOHO. The propagation speeds of the Moreton wave and
  the EIT wave were approximately 715 km s<SUP>-1</SUP> and 202 km
  s<SUP>-1</SUP>, respectively. The times of visibility for the Moreton
  wave did not overlap those of the EIT wave, but the continuation of the
  former is indicated by a filament oscillation. Data on the speed and
  location clearly show that the Moreton wave differed physically from
  the EIT wave in this case. The Moreton wave preceded the EIT wave,
  which is inconsistent with an identification of the EIT wave with a
  fast-mode MHD shock.

Title: Simultaneous Observation of a Moreton Wave on 1997 November
    3 in Hα and Soft X-Rays
Authors: Narukage, N.; Hudson, H. S.; Morimoto, T.; Akiyama, S.;
   Kitai, R.; Kurokawa, H.; Shibata, K.
Bibcode: 2002ApJ...572L.109N
Altcode:
  We report the observation of a Moreton wave in Hα (line center and
  +/-0.8 Å) with the Flare Monitoring Telescope at the Hida Observatory
  of Kyoto University at 4:36-4:41 UT on 1997 November 3. The same
  region (NOAA Active Region 8100) was simultaneously observed in soft
  X-rays with the soft X-ray telescope on board Yohkoh, and a wavelike
  disturbance (``X-ray wave'') was also found. The position of the wave
  front as well as the direction of propagation of the X-ray wave roughly
  agree with those of the Moreton wave. The propagation speeds of the
  Moreton wave and the X-ray wave are about 490+/-40 and 630+/-100 km
  s<SUP>-1</SUP>, respectively. Assuming that the X-ray wave is an MHD
  fast-mode shock, we can estimate the propagation speed of the shock, on
  the basis of MHD shock theory and the observed soft X-ray intensities
  ahead of and behind the X-ray wave front. The estimated fast shock
  speed is 400-760 km s<SUP>-1</SUP>, which is in rough agreement with
  the observed propagation speed of the X-ray wave. The fast-mode Mach
  number of the X-ray wave is also estimated to be about 1.15-1.25. These
  results suggest that the X-ray wave is a weak MHD fast-mode shock
  propagating through the corona and hence is the coronal counterpart
  of the Moreton wave.

Title: Reconnection Rate in the Decay Phase of a Long Duration Event
    Flare on 1997 May 12
Authors: Isobe, Hiroaki; Yokoyama, Takaaki; Shimojo, Masumi; Morimoto,
   Taro; Kozu, Hiromichi; Eto, Shigeru; Narukage, Noriyuki; Shibata,
   Kazunari
Bibcode: 2002ApJ...566..528I
Altcode:
  Recent analyses of long duration event (LDE) flares indicate successive
  occurrences of magnetic reconnection and resultant energy release
  in the decay phase. However, quantitative studies of the energy
  release rate and the reconnection rate have not yet been made. In
  this paper we focus on the decay phase of an LDE flare on 1997 May
  12 and derive the energy release rate H and the reconnection rate
  M<SUB>A</SUB>=v<SUB>in</SUB>/v<SUB>A</SUB>, where v<SUB>in</SUB> is
  the inflow velocity and v<SUB>A</SUB> is the Alfvén velocity. For this
  purpose, we utilize a method to determine v<SUB>in</SUB> and the coronal
  magnetic field B<SUB>corona</SUB> indirectly, using the following
  relations:H=2B<SUP>2</SUP><SUB>corona</SUB>/4πv<SUB>in</SUB>A<SUB>r</SUB>,B<SUB>corona</SUB>v<SUB>in</SUB>=B<SUB>foot</SUB>v<SUB>foot</SUB>,where
  A<SUB>r</SUB>, B<SUB>foot</SUB>, and v<SUB>foot</SUB> are the area of
  the reconnection region, the magnetic field strength at the footpoints,
  and the separation velocity of the footpoints, respectively. Since H,
  A<SUB>r</SUB>, v<SUB>foot</SUB>, and B<SUB>foot</SUB> are obtained from
  the Yohkoh Soft X-Ray Telescope data and a photospheric magnetogram,
  v<SUB>in</SUB> and B<SUB>corona</SUB> can be determined from these
  equations. The results are as follows: H is ~10<SUP>27</SUP> ergs
  s<SUP>-1</SUP> in the decay phase. This is greater than 1/10th of
  the value found in the rise phase. M<SUB>A</SUB> is 0.001-0.01,
  which is about 1 order of magnitude smaller than found in previous
  studies. However, it can be made consistent with the previous
  studies under the reasonable assumption of a nonunity filling
  factor. B<SUB>corona</SUB> is found to be in the range of 5-9 G, which
  is consistent with both the potential extrapolation and microwave
  polarization observed with the Nobeyama Radioheliograph.

Title: Multi-wavelength Observations of a Moreton Wave on 2000 March 3
Authors: Narukage, N.; Morimoto, T.; Kitai, R.; Kurokawa, H.;
   Shibata, K.
Bibcode: 2002aprm.conf..449N
Altcode:
  Moreton waves are flare-associated waves observed to propagate across
  the solar disk in Hα (Moreton, 1960). Such waves have been identified
  as the intersections of a coronal fast-mode shock fronts and the
  chromosphere (Uchida, 1968). We report the observation of a Moreton
  wave in Hα (line center and ± 0.8 Å) with the Flare Monitoring
  Telescope (FMT) at the Hida Observatory of Kyoto University on 2000
  March 3. The same region (NOAA 8882) was simultaneously observed in
  soft X-rays with the soft X-ray Telescope (SXT) on board Yohkoh, and
  a coronal wave-like disturbance (``X-ray wave") was also found. The
  region (NOAA 8882) is near the solar limb. Hence the chromospheric
  Moreton wave propagated on the solar disk at a speed of 1050 km/s,
  whereas the coronal X-ray wave propagated towards the outer corona
  at 1300 km/s. We identified the X-ray wave as an MHD fast-mode shock,
  i.e. a coronal counterpart of the Moreton wave, using MHD shock theory
  and the observed soft X-ray intensities (Narukage et al., 2002). On the
  basis of this result, the propagation of these two waves indicates the
  3-dimensional structure of the flare-associated shock wave. This event
  is the first observation of the 3-d structure of the shock. Moreover, a
  type II radio burst and a coronal mass ejection (CME) were also observed
  simultaneously. The shock speed given by the type II radio burst is 1150
  km/s. The CME propagated at a speed of 800 km/s. A basic component of
  CME is a density enhancement, and the shock preceding the CME propagates
  roughly 1.5 times faster than the CME, in this case at 1200 km/s.

Title: Multi-Wavelength Observation of A Moreton Wave on November
    3, 1997
Authors: Narukage, N.; Shibata, K.; Hudson, H. S.; Eto, S.; Isobe,
   H.; Asai, A.; Morimoto, T.; Kozu, H.; Ishii, T. T.; Akiyama, S.;
   Kitai, R.; Kurokawa, H.
Bibcode: 2002mwoc.conf..295N
Altcode:
  No abstract at ADS

Title: Statistical Study of the Reconnection Rate in Solar Flares
Authors: Isobe, H.; Morimoto, T.; Eto, S.; Narukage, N.; Shibata, K.
Bibcode: 2002mwoc.conf..171I
Altcode:
  The soft X-ray telescope (SXT) aboard Yohkoh has established that the
  driving mechanism of solar flares is magnetic reconnection. However,
  the physics of reconnection has not been clarified. One of the
  current puzzles is: what determines the reconnection rateNULL The
  reconnection rate is defined as reconnected magnetic flux per unit time
  or equivalently the ratio of inflow speed into reconnection point to
  Alfven velocity in non-dimension, and is one of the most important
  physical quantities in reconnection physics. However, observations
  have not yet succeeded to statistically determine the reconnection rate
  because direct observation of reconnection inflow and coronal magnetic
  field is difficult. In this poster we present a method to determine
  the reconnection rate from observational data, which use the following
  relations: H = frac B<SUP>2</SUP> 4pi v<SUB>in</SUB>L<SUP>2</SUP>
  v<SUB>in</SUB>B = v<SUB>foot</SUB>B<SUB>foot</SUB>. Here H, L,
  v<SUB>foot</SUB> and B<SUB>foot</SUB> are respectively the flare
  heating rate, size of the flare arcade, separation velocity of the two
  ribbon, and magnetic field strength of the foot points. Since these four
  quantities can be obtained from observational data, the relations above
  give the inflow velocity v<SUB>in</SUB> and coronal magnetic field B,
  and thus the reconnection rate can be determined. Appling this method
  to many flare observations, we will determine the reconnection rate
  in solar flares statistically. A preliminary result is presented.

Title: Simultaneous observations of Moreton waves in Hα and Soft
    X-ray
Authors: Narukage, N.; Hudson, H.; Morimoto, T.; Kitai, R.; Kurokawa,
   H.; Shibata, K.
Bibcode: 2002cosp...34E1337N
Altcode: 2002cosp.meetE1337N
  Moreton waves are flare-associated waves observed to propagate
  across the solar disk in H (Moreton, 1960). Such waves have been
  identified as the intersections of a coronal fast-mode shock fronts
  and the chromosphere (Uchida, 1967). We report the two observations of
  Moreton waves in H (line center and +/- 0.8 A) with the Flare Monitoring
  Telescope (FMT) at the Hida Observatory of Kyoto University. The both
  events were simultaneously observed in soft X-rays with the Soft X-ray
  Telescope (SXT) on board Yohkoh, and wave-like disturbances ("X-ray
  wave") were also found. One event occurred in solar-disk on November 3,
  1997, the other near solar limb on March 3, 2000. Assuming that the
  X-ray waves are the MHD fast shocks, we can estimate the propagation
  speeds of the shocks, based on the MHD shock theory and the observed
  soft X-ray intensities ahead and behind the X-ray wave fronts. It is
  found that the estimated fast shock speeds are in rough agreement with
  the observed propagation speeds of the X-ray waves. The fast mode Mach
  numbers of the X-ray waves are also estimated. These results suggest
  that the X-ray waves are MHD fast shocks propagating through the corona
  and hence are the coronal counterparts of the Moreton waves.

Title: Observations of Moreton Waves and EIT Waves
Authors: Shibata, K.; Eto, S.; Narukage, N.; Isobe, H.; Morimoto,
   T.; Kozu, H.; Asai, A.; Ishii, T.; Akiyama, S.; Ueno, S.; Kitai, R.;
   Kurokawa, H.; Yashiro, S.; Thompson, B. J.; Wang, T.; Hudson, H. S.
Bibcode: 2002mwoc.conf..279S
Altcode:
  The Moreton wave is a flare-associated wave observed in H alpha, and
  is now established to be a fast mode MHD shock emitted from the flare,
  but the physical mechanism to create the wave is still puzzling. On
  the other hand, the EIT wave is a newly discovered flare-associated
  wave observed in EUV with the Extreme ultraviolet Imaging Telescope
  (EIT) aboard SOHO, and in this case, not only its origin but also
  its physical property are both puzzling. We study the relationship
  of these two flare-associated waves, Moreton waves and EIT waves, by
  analyzing 4 events observed on Nov. 3 and 4, 1997, Aug. 8, 1998, and
  Mar. 3, 2000 (Narukage et al. 2001). The Moreton waves were observed
  in Ha, Ha+0.8A and Ha-0.8A with the Flare Monitoring Telescope (FMT)
  at the Hida Observatory of Kyoto University, while the EIT waves were
  observed with SOHO/EIT. In the typical case associated with an X-class
  flare in AR 8100 on 4 November 1997 (Eto et al. 2001) the propagation
  speeds of the Moreton wave and the EIT wave were approximately 780
  km/s and 200 km/s respectively. The data on speed and location show
  clearly that the Moreton wave differs physically from the EIT wave in
  this case. The detailed analyses of the other events (Nov. 3, 1997,
  Aug. 8, 1998, and Mar. 3, 2000) will also be presented, with Yohkoh/SXT
  data in the lucky case.

