2007/12/08-10Hinode Workshop in China1 HINODE/X-Ray Telescope R. Kano （ NAOJ ） & Japan-US XRT Team Golub et al. “The X-Ray Telescope (XRT) for the Hinode Mission” 2007, Solar Physics, 243, pp Kano et al. “The Hinode X-Ray Telescope (XRT): Camera Design, Performance and Operations” 2007, Solar Physics, in press.

2007/12/08-10Hinode Workshop in China 秒角という超高空間分解能 で、太陽表面の磁場ベクトルを精 密計測 約１秒角の高解像度で、コロナの構造 やそのダイナミックな変動を観測 コロナの物質が出す極端紫外線を撮像・分 光し、コロナ物質の密度・温度・流れの状 態を診断 ３望遠鏡の同時観測により、 太陽コロナ活動や加熱機構のメカニズムを探 る Hinode EUV Imaging Spectrometer: EIS Solar Optical Telescope: SOT X-ray Telescope: XRT

2007/12/08-10Hinode Workshop in China3 Outline 1.Introduction of X-ray telescope 2.Control of XRT observations 3.Coronal temperature diagnostics 4.Summary

2007/12/08-10Hinode Workshop in China4 1. Introduction of XRT

2007/12/08-10Hinode Workshop in China5 SAO Front Door and Hinge Assembly Electrical Box Ascent Vents 2 places Graphite Tube Assembly CCD Camera and Radiator This is XRT NAOJ ISAS

2007/12/08-10Hinode Workshop in China6 Front Door and Hinge Assembly Electrical Box Ascent Vents 2 places Graphite Tube Assembly CCD Camera and Radiator Grazing Incidence X-ray Mirror Back-Illuminated CCD: 2k x 2k pixel Optimized set of focal-plane filters Sophisticated observation control by MDP This is XRT

2007/12/08-10Hinode Workshop in China7 XRT Optics Grazing incident X-ray optics. Visible light (G-band) optics on the central axis shears one CCD with the X-ray optics, and its images are used for the co-alignment with SOT

2007/12/08-10Hinode Workshop in China8 Optical Performance Increased spatial resolution while maintaining FOV covering the whole Sun –~3 times higher (1 arcsec pixel size) than Yohkoh/SXT = highest ever achieved for soft X-ray telescopes for the Sun. Focus adjustment mechanism –Imaging with the highest resolution for areas covering SOT/EIS field of view. –Or, full-Sun imaging with a moderate (2 - 3”) resolution. Point Spread Function ※ Al K (8.34A) Cu-L line(13.3A) XRT SXT high resolution in narrow FOV moderate resolution for wide FOV

2007/12/08-10Hinode Workshop in China9 XRT analysis filters XRT has 9 X-ray filters and 1 visible light filter. Thin-Be Med-BeC-Poly Thin-Al -Poly Med-Al open G-band Thick-AlTi-Poly Thin-Al -Mesh Thick-Be open

2007/12/08-10Hinode Workshop in China10 XRT analysis filters Adjacent filter pairs for temperature diagnostics. Both SXT-like and TRACE-like filters included in the set. Optimized filter selection and layout

2007/12/08-10Hinode Workshop in China11 Key features of XRT Continuous coverage of the entire temperature range in the corona for ≳ 1 MK plasmas … Capable of observing entire plasma processes that take place in the corona, with temperature diagnostic capability High angular-resolution/contrast observations for high temperature ( ≳ 2 MK) plasmas

2007/12/08-10Hinode Workshop in China12 Angular resolution (CCD Pixel Size) Temperature range 0.5” 1” 2.5” Yohkoh/SXT (Full Sun) SoHO/EIT (Full Sun) TRACE (Partial) Hinode/XRT (Full Sun) ～ 2 MK Scientific Location of XRT (Angular resolution and temperature range)

2007/12/08-10Hinode Workshop in China13 Hinode XRTYohkoh SXT Hinode XRT and Yohkoh SXT Images at a Same Solar Activity Phase Spatial resolution 1 arcsec 5 arcsec

2007/12/08-10Hinode Workshop in China14 Hinode XRTYohkoh SXT Active Region

2007/12/08-10Hinode Workshop in China15 Hinode XRT Yohkoh SXT Quiet Region

2007/12/08-10Hinode Workshop in China16 Hinode XRTYohkoh SXT Bright points now resolved into ensemble of loops X-ray Bright Points

2007/12/08-10Hinode Workshop in China17 XRT Sciences Photosphere-Corona connection Formation and heating of the corona incl. energy transport, storage, and dissipation Outer-corona investigation extending to CME and solar wind investigations imaging observation of the soft X-ray/XUV corona with advanced imaging and temperature- diagnostic capabilities. Vast varieties of active, or even non-active, phenomena in the corona:

2007/12/08-10Hinode Workshop in China18 2. Control of XRT observations

2007/12/08-10Hinode Workshop in China19 On-board functions for XRT Obs. Mission Data Processor DR Image Compression Pre-Flare Buffers Autonomous Functions FLDARSAEC XRT Observation Tables Data Packet Edition SOT EIS Mission Data Processor (MDP) has many functions for XRT. Management of XRT exposures by “Observation Table” Autonomous Functions for XRT observations –Automatic Exposure-duration Control (AEC) –Automatic Region Selector (ARS) –FLare Detection (FLD) Image processing –Edition of Image data packets –Image compression –Pre-Flare Buffers

2007/12/08-10Hinode Workshop in China20 Observation Table Program No.1 “Normal Obs.” 1.SUB1 loop=10 2.SUB3 loop=1 3.SUB2 loop=10 4.SUB3 loop=1 SEQ1: global structure of 1MK corona Exp. for thin-Al-mesh & full FOV Exp. for thin-Al-poly & full FOV SEQ2: AR’s temperature structure Exp. for thin-Al-poly & small FOV (AR) Exp. for med-Be-mesh & small FOV (AR) SEQ3: 1MK corona in AR Exp. for thin-Al-mesh & small FOV (AR) Exp. for thin-Al-poly & small FOV (AR) SEQ100: CCD dark calibration Sequence Table (100 sequences) Observation Program (20 programs) SUB1 1. SEQ1 loop=1 2. SEQ2 loop=20 SUB2 1. SEQ1 loop=1 2. SEQ3 loop=20 SUB3 1. SEQ100 loop=1 ： XRT exposures are managed by one observation table in the Mission Data Processor (MDP). The structure of XRT observation table is essentially the same with those for SOT.

2007/12/08-10Hinode Workshop in China21 Automatic Exposure-duration Control (AEC) Exposure duration is adjusted by using the intensity histogram. LLT ULT Intensity I Number of pixel LLT ULT Intensity I Number of pixel LLT ULT Intensity I Number of pixel Under Exposure Normal Exposure Over Exposure If U is too much, shorten the exposure duration. If L is not enough, lengthen the exposure duration. F(I)

2007/12/08-10Hinode Workshop in China22 Automatic Region Selector (ARS) XRT will take an “ARS patrol image” (the full CCD-frame and 2”-resolution) once per orbit (every 90 min typically). Two modes of ARS run in parallel each other. –“Global Search” mode to fine the brightest region. –“Local Search” mode to track bright regions.

2007/12/08-10Hinode Workshop in China23 ARS: Global Search Steps to derive a new FOV Take a new patrol image. Define the search area. (The default is all CCD.) Make a macro-pixel image. Pick up the brightest macro- pixel. Calculate a fine position in the original image around the selected macro-pixel. New FOV

2007/12/08-10Hinode Workshop in China24 Automatic Region Selector (ARS) XRT will take an “ARS patrol image” (the full CCD-frame and 2”-resolution) once per orbit (every 90 min typically). Two modes of ARS run in parallel each other. –“Global Search” mode to fine the brightest region. –“Local Search” mode to track bright regions.

2007/12/08-10Hinode Workshop in China25 ARS: Local Search Steps to derive a new FOV Take a new patrol image. Define the search area. (Just around the current FOV) Calculate a fine position in the search area. Current FOV New FOV

2007/12/08-10Hinode Workshop in China26 30 sec (typically) Flare Detection (FLD) XRT will take a FLD patrol image every 30 sec (typically). MDP derives a difference image between a new patrol image and the running averaged patrol image, and searches any intensity enhancement in it. Once a flare occurred, MDP informs the flare position to SOT and EIS also. (FLD function is useful to avoid strong irradiation to CCD.) difference average Flare has detected! Flare is lasting. Flare has terminated. FLD patrol image Averaged image

2007/12/08-10Hinode Workshop in China27 Pre-Flare Buffers Buffer0 Buffer1 Buffer2 Buffer3 “SW1” “SW2” “SW3” X X−100sX−200sX−300s time Total Buffer0 Buffer1 Buffer2 Buffer3 Data Recorder Four buffers is available for the image transfer to the Data Recorder. Buffer0 is prepared for the normal image transfer. Buffer1, 2, and 3 for ring buffers to freeze the pre-flare images.

2007/12/08-10Hinode Workshop in China28 On-board functions for XRT Obs. Mission Data Processor DR Image Compression Pre-Flare Buffers Autonomous Functions FLDARSAEC XRT Observation Tables Data Packet Edition SOT EIS Mission Data Processor (MDP) has many functions for XRT. Management of XRT exposures by “Observation Table” Autonomous Functions for XRT observations –Automatic Exposure-duration Control (AEC) –Automatic Region Selector (ARS) –FLare Detection (FLD) Image processing –Edition of Image data packets –Image compression –Pre-Flare Buffers

2007/12/08-10Hinode Workshop in China29 Parameters of XRT Performance X-Ray Optics OpticsOptimized Wolter-I-like grazing incidence optics Focal length2708 mm Mirror micro-roughness6 Å expected (TBD; analysis ongoing) Aperture size> 340 mm Spatial resolution68 % of encircled energy in 2 arcsec (at keV) Wavelength range6–200 Å Effective area> 1.0 cm 2 at keV Visible Light Optics Focal length2708 mm Wavelength4305 Å (G-band) Focal Plane CCD Camera CCD deviceE2V 2048×2048 back-illuminated Pixel Size 13.5  m = 1.0 arcsec Field of view34×34 arcmin (capable of covering the whole Sun) Image readout500 kpixel/s

2007/12/08-10Hinode Workshop in China30 3. Coronal temperature diagnostics

2007/12/08-10Hinode Workshop in China31 Spectrum of Solar Corona Hotter plasma is brighter in short wavelengths. Spectrum of the solar corona is modeled as an optically thin plasma, and consists of a continuum and emission lines. XRT is a sensitivity around Å to observe a low temperature corona (100MK).

2007/12/08-10Hinode Workshop in China32 XRT analysis filters XRT has 9 X-ray filters and 1 visible light filter. Thin-Be Med-BeC-Poly Thin-Al -Poly Med-Al open G-band Thick-AlTi-Poly Thin-Al -Mesh Thick-Be open

2007/12/08-10Hinode Workshop in China33 XRT Response (Effective Area) Nine X-ray filters. Wide-wavelength coverage. To observe 100MK plasma, XRT has a sensitivity at 170 – 200Å with thin-Al-mesh.

2007/12/08-10Hinode Workshop in China34 * Coronal Intensity detected with XRT x = Coronal spectrum at a certain logT × XRT effective area ＝ A wavelength distribution of the coronal intensity with logT detected with XRT.  We derive a total intensity of the corona at logT detected with XRT, by integrating it over wavelengths.  By plotting total intensities at several temperatures, … we derive a “temperature response: f filter (T)”.

2007/12/08-10Hinode Workshop in China35 filter ratio method

2007/12/08-10Hinode Workshop in China36 Filter ratio method Assumption : XRT observe same plasma with filter1 and filter2. filter ratio function The estimated temperature is the mean temperature. filter ratio method

2007/12/08-10Hinode Workshop in China37 Temperature Diagnostics with XRT Low-Temperature Structure around an AR

2007/12/08-10Hinode Workshop in China38 4. SUMARRY (1) XRT holds a unique position among solar SXR/EUV telescopes currently on orbit or being planned: * Continuous coverage of the entire temperature range in the corona for ≳ 1 MK plasmas … Capable of observing entire plasma processes that take place in the corona, with temperature diagnostic capability * High angular-resolution/contrast observations for high temperature ( ≳ 2 MK) plasmas Autonomous functions to support various observations of coronal dynamics.

2007/12/08-10Hinode Workshop in China39 4. SUMARRY (2) Structure and evolution of coronal magnetic fields and their associated temperatures can be investigated in great detail. Expected to serve as a key instrument for investigating photosphere-corona connection. At the same time, may have non-negligible impact on heliospheric study.