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ひので SOT

ひので SOT. 2013.11.26 一本 観測＆装置ゼミ. １．可視光望遠鏡概要. - Optical Telescope Assembly (OTA) - Focal Plane Package (FPP). OTA: f 50cm Gregorian Telescope. FPP:. M2. HDM (Heat Dump Mirror). OTA と FPP はコリメート光で結び構体変形による焦点移動を回避 PMU は瞳像の近くにおきゴミやむらによる輝度変調を排除偏

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ひので SOT

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  1. ひので SOT 2013.11.26 一本 観測＆装置ゼミ

  2. １．可視光望遠鏡概要 - Optical Telescope Assembly (OTA) - Focal Plane Package (FPP) OTA: f50cm Gregorian Telescope FPP: M2 HDM (Heat Dump Mirror) • OTAとFPPはコリメート光で結び構体変形による焦点移動を回避 • PMUは瞳像の近くにおきゴミやむらによる輝度変調を排除偏 • 偏光モジュレータ(PMU)までは軸対称な光学系 　MT = E • FPPに向かう光線はTip-tilt mirrorにより像安定化 2次焦点絞り M1 CLU (collimator Lens Unit) PMU (Polarizaiton Modulator Unit) Tip-tilt mirror

  3. OTA FPP OBU SOTセミナー＠花山　2004.12.7

  4. Gregorian telescope Aperture area f500mm, 153434mm2 Linear central obscuration 0.344( = 172/500 ) HDM outer diameter 32.83mm (Maximum offset pointing angle) Effective f-length at secondary focus 4527 25 mm Effective F-ratio at secondary focus 9.055 0.05 Plate scale at secondary focus 21.95 mm/arcsec Field of view 360 x 200 arcsec Exiting beam Collimation Collimated in air Angular magnification 16.667 Exit pupil size f30.0 mm Exit pupil position -73.05 from tip-tilt mirror Chromatic aberration Nearly zero (<35mm 388—670nm) OTA光学系の基本パラメータ SOTセミナー＠花山　2004.12.7

  5. 排熱鏡の大きさで決まるSOT(Solar-B)の指向範囲 FOV of Heat Dump Mirror D◎=32’35” Sun SOT FOV max.offset = 19.6’ margin ～1.2’ HDM外径　32.83mm Maximum offset pointing of Solar-B < 19.6’

  6. OTA斜入射危険領域MAP 第２待避領域 q = 25+5o 遷移領域 許容滞在時間　8min – 10hr 排熱窓 HDM 全頂角22oコーン 許容滞在時間　 ∽ +Y 排熱窓 主鏡に入射。熱が内部にこもる Center sec. ~ 45W Cold plate ~ 72W Truss ~ 26W(合計) Sun shade裏 ~ 40W q = 10 ~ 16o 許容滞在時間　 ~12 hr 118o 90o 遷移領域 q = 10 ~ 16o 許容滞在時間　12 hr - ∽ 排熱窓 副鏡 全頂角11oコーン 許容滞在時間　 ∽ 30o ~16o 4o ~10o 20o +X 衛星後部から太陽を指向 したときの衛星座標軸 安全領域 q > 20o 許容滞在時間　∽ 内スパイダー ~ 240W/cm2 0.327o < q < 4o 許容滞在時間 < 20 min 比較的安全領域 4.5o < q < 9o f = 0,120,240o+ 10o 開口からの排熱　~ 100W CLU, PMU, CTM-TM温度  ~90C 許容滞在時間　> 10 hr 排熱鏡円筒 ~ 90W/cm2 副鏡 ~ 215W 0.327o < q < 4o 許容滞在時間 < 20 min 外スパイダー ~ 10W/cm2 4o < q < 10o, f = 60, 180, 300o+ 15o 許容滞在時間　< 8 min 安全領域（通常観測時） q < 0.327o 2000.12.04 MELCO-OTA/NAOJ

  7. ２次絞りでも不要な光を排熱

  8. M1 (FM sample) M2 (FM sample) CTM-TM (theoretical) CLU (FM measurement) BFI wavelengths NFI wavelengths

  9. Optical layout of SOT LitrowMirror Polarizing BS Folding Mirror Spectoro-polarimeter Dual 256 x 1024 CCD X3 Mag lens Polarizing BS Folding Mirrors Shutter Slit Field lens Grating Field lens X2 Mag lens Filterwheel Shutter Preslit 4096 x 2048 CCD Filterwheel FieldMask Birefringent Filter Broadband Filter Instrument Narrowband Filter Instrument 50 x 50 CCD Secondary Telecentric lenses Correlation Tracker BeamDistributor Demag lens HDM Folding Mirror ReimagingLens Image Offset Prisms Folding Mirror OTA Astigmatism corrector lens Color Coding OTA Common Optics CT NFI BFI SP Primary PolarizationModulator CLU Tip TiltMirror

  10. FPP光学レイアウト SP-CCD PBS SP PBS BFI NFI CT-CCD FG-CCD • - (X, l, P) を同時取得するSP系と(X, Y, P) を同時取得するFG系の共存 • SPはCCD直前のPBSにより両偏光同時取得 • BFIのメカシャッタは像面におき回折限界を確保、 • NFIのメカシャッタは瞳位置におき像面内の波長板位相差をなくす • NFIを通る光線はテレセントリックとし、透過波長は像面内で一様とする SOTセミナー＠花山　2004.12.7

  11. SP Littrow Mirror SP CCD Radiator SP Littrow Grating BFI/NFI Beam Combiner SP CCD Electronics SP Slit BFI Shutter BFI Filterwheel NFI Focalplane Mask Beam Distributor SP Slit Scanner NFI Shutter BFI/NFI CCD Radiator NFI Lyot Filter BFI/NFI CCD Electronics NFI Filterwheel CT CCD Electronics CT wedge wheel FPP Mechanical Design SOTセミナー＠花山　2004.12.7

  12. SOT観測波長 SOTセミナー＠花山　2004.12.7

  13. SOT観測量と基本スペック SOTセミナー＠花山　2004.12.7

  14. Tunable Filter 半値幅～100mA SOTセミナー＠花山　2004.12.7

  15. Partial polarizer を用いたLyot ブロック polarizer calcite Partial polarizer L calcite polarizer 2L p (p=1で完全偏光板)を小さくするとサイドローブが抑制される。 Lと2L calcite の速い軸が90o違っていることがミソ。 間のpolarizer がなかったらL+2L でLのLyot element と等価、その電場がサイドローブの2L電場を打ち消す。(Title 1974, Sol.Phys., 38, 523.)

  16. Schematics of the SOT polarimeter Polarization modulator unit (PMU) OTA Collimator lens unit (CLU) HDM CTM-TM Pupil image Astigmatism corrector lens (ACL) M2 M1 NFI- Polarization analyzer Mask wheel Mech. shutter Reimaging lens Tunable filter FG/NFI Non-polarizing beam splitter FG-CCD Blocking filter wheel SP Slit scan mirror Slit SP- Polarization analyzer (beam splitter) SP-CCD left/right

  17. Appendix-6: PMU waveplate (2007.02.11 BFI retardation from D.Elmore) 5.35l @630nm 6.65l @517nm The thermal constraint required the quartz and sapphire parts have a thickness ratio of 1.17. Our compromise: approximately maintain that ratio, while searching for dual-wavelength designs meeting the N ± 0.35 specification. We succeeded with 5.35 waves at 630 nm and 6.65 waves at 517 nm. Crystal Retarder Design Strategies: A Tutorial By Stephen J. Guimond, Meadowlark Optics and David F. Elmore, High Altitude Observatory, National Center for Atmospheric Research* l d 388.350 9.3380 396.850 9.0947 430.500 8.2507 450.450 7.8240 517.200 6.6822 525.000 6.5720 555.050 6.1664 589.600 5.7624 630.200 5.3442 656.300 5.1095 668.400 5.0086

  18. Polarization modulation and demodulation V U Q Waveplate angle [deg.] PMU segment 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 + + + + + + + + + + + + + + + +  I’ + - - + + - - + + - - + + - - +  Q’ + + - - + + - - + + - - + + - -  U’ - - - - + + + + - - - - + + + +  V’ SP onboard demodulation

  19. SOT modulation profiles from the measured PMU retardance 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Q V U

  20. Detection limit of FG for the weak magnetic fields, e = 0.001 I’: line profiles convoluted by TF transmission curve 2nd moments of s and p-components

  21. SOT polarimetric observables SP (Spectropolarimeter) FeI 6301 & 6302A full Stokes profiles Dual beam Continuous readout, 16 frames/rev. Onboard demodulation/accumulation Left/right sequential frame transfer NFI (Narrowband Filter Imager) 0.1A Lyot filter Shutterless mode Continuous readout, 16frames/rev Central portion w/ focal plane mask Shutter mode Use mechanical shutter Expose entire CCD simultaneously CCD 1 2 Example of shutter timing Stokes-V obs.

  22. SOT observables FG: - simple image - Dopplergram (2 wavelengths) - Stokes IV - Stokes IQUV - IVDG (2 wavelengths) SP: - normal mode (0.16” step, 4.8s/slit) - fast mode (0.32” step, 3.2s/slit) - dynamic mode (0.16” step, 1.6s/slit) - deep mode (0.16” step, 9.6s/slit)

  23. 試験 • 光学性能 • 機械環境 • 熱光学 • 微小擾乱 • 偏光特性 • アウトガス

  24. 5. OTA flight model integration clinometer Vertical meter Target mirror Reference flat Alignment cube M2 Dummy OBU OTA Rotation mechanism Interferometer MiniFiz M1 Six axis stage Telescope Up Optical bench • OTA is integrated on a dedicated tower. • Interferometoric measurement is performed with f60cm reference flat at the top of tower. • OTA can be upside top and upside down to cancel gravity.

  25. OTA光学測定 SOTセミナー＠花山　2004.12.7

  26. OTAの結像性能 OTA波面　重力変形による３角アス 上下反転により求めた無重力での WFE 20nm rms~ l/32 rms @633nm || Strehl ~ 0.96 軌道上温度変化により徐々に劣化する. ミッション期間 において　Strehl > 0.8 SOTセミナー＠花山　2004.12.7

  27. OTA Opto-thermal testing -- motivation -1.7~ 25.0 C Heater control -21.5 ~ 4.4C -27.8 ~ 4.6C 21.1 ~ 67.3 C 1.1 ~ 16.3 C 19.9 ~ 43.2 C 16.0 ~ 30.0 C 26.2 ~ 45.7 C Heater control Predicted OTA temperature in orbit Large DT from the ground testing. Large dT/dz.

  28. OTA Opto-thermal testing -- configuration Reference mirror  OTA pointing ax. Theodolite  OTA center of FOV Upper shroud OTA interferometer Dummy OBU Support theodlite  alignment cube. Lower shroud OTA alignment cube flat mirror shroud Flat mirror reference Tilt/shift stage Autocollimator  OTA pointing ax. WFE of OTA is measured in a dedicated vacuum chamber. Two shrouds control the OTA temperature as it is in orbit.

  29. ・副鏡ヒータOn/Off でフォーカスがガンガン変わる ・排熱鏡スパイダーの温度でフォーカスが変わる ・望遠鏡が真空中で縮む ・スパイダーに張ったケーブル止めメタルでフォーカスが変わる ・主鏡面形状の温度による不連続変化

  30. ２．擾乱源 Solar-Bの中にある可動物 モメンタムホイール(MW x ４台)、 慣性系基準装置（ジャイロ：IRU-A, IRU-B）、 SOT: Fホイール３台、シャッター２個、 回転波長板１個、チュナブルフィルタ、 スリットスキャン、計８ XRT: Fホイール２台、シャッター１個 可視光シャッター１個、フォーカス、 計５ EIS: スリットタレット１台、シャッター１個 ミラーtilt粗微、計４ 擾乱の周波数と大きさ（擾乱力は初期予想値）

  31. 「ひので」可視光望遠鏡の像安定要求 = 0.09”(3s) / 10sec 像の振動と点像の劣化 l=500nm 要求値 l=390nm 画像が１方向に正弦波的に振動したときの回折限界点像（上：500nm, 下：390nm）。

  32. SOT system overview CCD 50 x 50pix, 540Hz 像安定化装置（CT）が画像を安定化するのは15Hz 以下。

  33. 2006.10.31 CT servo-On, error signal/TM angle time profiles Servo-off

  34. 2010.2.5

  35. theodolite PSD ３．指向擾乱測定方法 レーザー光による測定 加速度センサーによる測定 望遠鏡鏡に加速度センサー取り付け 衛星バネ吊り MTM FPP光学センサーによるend-to-end 衛星床置き FM 630nm tunable laser dolly 長所：光学的にend-to-end な測定 短所：建物からのノイズが大きい 　　　　軌道上と境界条件が異なる 長所：建物からのノイズが小さい Free-Free境界条件の模擬ができる 短所：像擾乱の間接的な測定、M1//M2のみ

  36. 一噛み(2004.11)における２つの測定（フライト品）一噛み(2004.11)における２つの測定（フライト品） 衛星をバネで吊り上げ、望遠鏡の鏡に取り付けた加速度センサーで擾乱を測定する。 衛星を頑丈なタワーの中に置き、光を望遠鏡に入れて画像から擾乱を測定する。

  37. Seq.4 吊り下げ 周波数方向に積分したモメンタムホイールによる指向誤差。 total 1800+100rpm or 2800+100rpm

  38. 最終フライトモデルによる擾乱測定結果 主な稼動メカニズムについて総合試験における３回の測定結果を並べて表示してある。要求レベル（0.03”rms）を超えているのはXRT-VLS（可視光シャッタ）のみである。XRT-VLSについては使用頻度を低く抑える（１時間に１回程度）ことで観測への影響を回避する。

  39. S Telescope, MT Configuration of a spectro-polarimeter can be modeled by a chain of Mueller matrices S’ Polarization analyzer, MA Spectrometer, MF Polarization modulator, MP,k detector Feed optics, MB S: incident stokes vector S’k: Stokes vector at detector

  40. Schematics of the SOT polarimeter Polarization modulator unit (PMU) OTA Collimator lens unit (CLU) HDM CTM-TM Pupil image Astigmatism corrector lens (ACL) M2 M1 NFI- Polarization analyzer Mask wheel Mech. shutter Reimaging lens Tunable filter FG/NFI Non-polarizing beam splitter FG-CCD Blocking filter wheel SP Slit scan mirror Slit SP- Polarization analyzer (beam splitter) SP-CCD left/right

  41. Flow of the polarization measurement ‘Polarization measurement’ is achieved by measuring a number of I’ (first element of S’) at different Mp I’k = mI,k I + mQ,k Q + mU,k U + mV,k V k = 1,2,,,,N modulation： S’k = Mk S I’ = W S W: 4 x N matrix polarization measurement matrix demodulation：obtain S from [I’] S = D I’D : N x 4 demodulation matrix for N > 4 D = ( Wt W)-1Wt--- least square solution of S (ideal demodulation matrix)

  42. Polarization modulation and demodulation V U Q Waveplate angle [deg.] PMU segment 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 + + + + + + + + + + + + + + + +  I’ + - - + + - - + + - - + + - - +  Q’ + + - - + + - - + + - - + + - -  U’ - - - - + + + + - - - - + + + +  V’ SP onboard demodulation

  43. Flow of the polarization measurement SOT polarimeter ST Incident to polarimeter S Incident Stokes vector Telescope ST = TS Measurement error: DS S’ = XS Polarization modulation + noise I’ = W ST + e S’ SOT product I’ modulated intensity S” reduced Stokes vector on-board demodulation S’ = D I’ Ground calibration Xr-1S’ S” X: Polarimeter response matrix (4x4) X : true matrix Xr: matrix determined by polarization calibration Calibration error: DS” = S” – S = Xr-1 XS– S = (Xr-1 X– E) S Statistical noise: dS” = Xr-1dS’ = Xr-1 e

  44. Requirement on X • Calibration error :DS= S” - S = { Xr-1X- E } S • Statistical noise : dS” = Xr-1dS’ = Xr-1e • e = (e , e, e, e) t • photometric noise Requirement =DS < dS” DX ≡ X- Xr : required accuracy for Xr

  45. Requirement on X DX S < e Scale errors [ Q,U,V ] / I = Pobs = (1 + ds) Preal + db false signal error < e scale error < a (allow ambiguity, cf. Stokes inversion) Difference between p= 0% and p= 0.1% is important, but difference between p=10% and p=10.1% is not important

  46. Requirement on X Scale errors Let’s Consider individual elements and allow scale error < a then

  47. Requirement on X Scale error Hinode, SOT e = 0.001 a = 0.05 pl = 0.15 （max of Q,U） pc = 0.2　（max of V） Tolerance of DX (≡ O) Goal of polarization calibration is to determine the polarimeter response matrix, X, with an accuracy defined by this tolerance matrix.

  48. How to specify the required accuracy for polarization properties of individual optical elements1. Calculate polarimeter response matrix with and without an error (p) of polarization property of an element. 2. Compare DX ≡ X- Xrwith the tolerance matrix (O)3. If all elements of |DX| are smaller than the corresponding elements of O, then error p is acceptable, if one of them exceeds, then error p is not acceptable. Polarization tolerance of optical element

  49. Tolerance of optical element Example: rotating waveplate S φ ret: δ, angle: q DX (Dq) DX (Dd) Tolerance of angle ~ 0.1deg. from Q-U crosstalk Tolerance of ret.~ 3.7deg. from DV scale error

  50. Tolerance of optical element Polarimeter model MT = E MP = ideal rotating waveplate with d =126.7deg. 16 sampling MB = MCTM-TM MA = Mdiat with k=0.01 MF = Mdiat with k=0.001 * For errors whose axes are 45o to the PA-axis. Such error can occur for off-axis rays (~0.7deg.160” in FOV) in collimated beam entering on CTM-TM or BS.

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