1. 1 SOT instrument overview Kiyoshi Ichimoto NAOJ Hinode workshop, 2007.12.8-10, Beijing

2. 2 OTA:  50cm Gregorian Telescope FPP: HDM (Heat Dump Mirror) M2 M1 CLU (collimator Lens Unit) PMU (Polarizaiton Modulator Unit) Tip-tilt mirror Optical Telescope Assembly (OTA), is a Gregorian telescope with 50 cm aperture, built by NAOJ/ISAS. Focal Plane Package (FPP), includes observation filters, spectrometer, and cameras, built by LMSAL/HAO/NASA. Solar Optical Telescope SOT = OTA + FPP 1.5m

3. 3 SOT system overview

4. 4 OTA OBU FPP SOT (Solar Optical Telescope):

5. 5 Key Features of SOT Largest telescope ever built to observe the Sun from space Diffraction-limited images (0.2-0.3arcsec), achieved by 50- cm-diameter aperture Observation from space, free from the atmospheric seeing. Continuous observation for 24 hours per day in ~8 months per year, thanks to the sun-synchronous orbit of HINODE Stabilized image with the correlation tracker 388-668nm range, including spectral lines and continuums useful for studying photosphere and chromosphere Optimized for high precession polarization measurements in spectral lines, continuous modulation of Stokes IQUV in every 0.8sec. Provides accurate vector magnetic fields in the photosphere.

6. 6 Color Coding OTA Common Optics CT NFI BFI SP Polarization Modulator Folding Mirror 4096 x 2048 CCD Polarizing BS Birefringent Filter FilterwheelField Mask Field lens Shutter X2 Mag lens Folding Mirror Telecentric lenses X3 Mag lens Shutter Field lens Filterwheel Litrow Mirror Polarizing BS Folding Mirrors Slit Preslit Grating Folding Mirror Image Offset Prisms Demag lens 50 x 50 CCDSecondary Primary CLU Tip Tilt Mirror Reimaging Lens Beam Distributor Dual 256 x 1024 CCD Narrowband Filter Instrument Broadband Filter Instrument Spectoro-polarimeter OTA Correlation Tracker HDM Astigmatism corrector lens Optical layout of SOT

7. 7 SOT Optical Telescope Assembly (OTA)

8. 8 Gregorian telescope Aperture area  500mm, 153434mm 2 Linear central obscuration 0.344 ( = 172/500 ) HDM outer diameter32.83mm (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  m/arcsec Field of view360 x 200 arcsec Exiting beam CollimationCollimated in air Angular magnification16.667 Exit pupil size  30.0 mm Exit pupil position  73.0  5 from tip-tilt mirror Chromatic aberration Nearly zero (<35  m 388 — 670nm) Optical parameters of OTA

9. 9 Point Spread Function （ideal） 500 mm 40 mm 172 mm +Y

10. 10 5. OTA flight model integration  OTA is integrated on a dedicated tower.  Interferometoric measurement is performed with  60cm reference flat at the top of tower.  OTA can be upside top and upside down to cancel gravity.

11. 11 Gravitational deformation of OTA optics Average of upside top and upside down gives the Zero-G WFE ~ /20 rms @633nm Example of WFE map

12. 12 19.9 ~ 43.2 C 1.1 ~ 16.3 C  27.8 ~ 4.6 C  1.7 ~ 25.0 C 16.0 ~ 30.0 C 26.2 ~ 45.7 C Heater control  21.5 ~ 4.4 C 21.1 ~ 67.3 C Heater control Large  T from the ground testing. Large dT/dz. Predicted OTA temperature in orbit OTA Opto-thermal testing -- motivation

13. 13 OTA Opto-thermal testing -- configuration WFE of OTA is measured in a dedicated vacuum chamber. Two shrouds control the OTA temperature as it is in orbit.

14. 14 D ◎ =32’35” max.offset = 19.6’ SOT FOV margin ～ 1.2’ Heat Dump Mirror at primary focus focus Sun Maximum offset of Hinode pointing = 19.6 arcmin HDM outer diameter 32.83mm Maximum offset pointing of SOT

15. 15 CLU (FM measurement) M1 (FM sample) CTM-TM (theoretical) NFI wavelengths BFI wavelengths M2 (FM sample)

16. 16 FPP Mechanical Design BFI/NFI CCD Radiator BFI/NFI CCD Electronics SP CCD Radiator SP CCD Electronics NFI Lyot Filter CT CCD Electronics SP Littrow Mirror SP Littrow Grating SP Slit BFI Filterwheel BFI Shutter NFI Shutter BFI/NFI Beam Combiner SP Slit Scanner NFI Filterwheel Beam Distributor NFI Focalplane Mask CT wedge wheel SOT Focal Plane Package (FPP)

17. 17 HINODE SOT has four optical paths: 1.Broadband Filter Imager (BFI)images with highest spatial resolution 2.Narrowband Filter Imager (NFI)wide FOV, high resol. mag./Dopp., chrom. 3.Spectro-Polarimeter (SP)precise photospheric magnetic fields 4.Correlation Trackerimage stabilization

18. 18 BFINFISPCT CCD format4096 x 2048112 x 1024 x 250 x 50 pixel scale (arcsec/pix)0.0540.080.160.22 328x164 ~0.1 1~4 10~60s 0.1 ~ 0.5 maximum FOV (arcsec 2 ) (EWxNS) 218x109328 (scan range) x164 (slit length) 11x11 wavelength resolution (A)3~100.025 number of wavelength in a data set 12441 time resolution (typical)5~30s1min~3hr580Hz photometric aquracy (%)0.5~ 0.1~0.5 Basic parameters of four optical paths:

19. 19 SOT broadband filters Field of view218" × 109" (full FOV) CCD4k × 2k pixel (full FOV), shared with the NFI Spatial Sampling0.0541 arcsec/pixel (full resolution) Spectral coverage Center (nm)Width (nm)Line of interestPurpose 388.350.7CN IMagnetic network imaging 396.850.3Ca II HChromospheric heating 430.500.8CH IMagnetic elements 450.450.4Blue continuumTemperature 555.050.4Green continuumTemperature 668.400.4Red continuumTemperature Exposure time0.03 - 0.8 sec (typical)

20. 20 SOT narrowband filter Field of view328"×164" (unvignetted 264"×164") CCD4k×2k pixel (full FOV), shared with BFI Spatial sampling0.08 arcsec/pixel (full resolution) Spectral resolution0.009nm (90mÅ) at 630nm Spectral windows (nm) and lines of interest Center -range Linesg eff Purpose 517.20.6Mg I b 517.271.75Dopplergrams and magnetograms 525.00.6Fe 524.712.00Photospheric magnetograms Fe I 525.023.00 Fe I 525.061.50 557.60.6Fe I 557.610.00Photospheric Dopplergrams 589.60.6Na I D 589.61.33Very weak fields (scattering polarization) Chromospheric fields 630.00.6Fe I 630.151.67Photospheric magnetograms Fe I 630.252.50 Ti I 630.380.92Umbral magnetograms 656.30.6H I 656.28~1.3?Chromosphreic structure Exposure time0.1 - 1.6 sec (typical)

21. 21 SOT SP (Spectro-Polarimeter) Fe I 630.15nm and 630.25nm Obtain spectra at 16 angular positions of polarization modulator 83min for 160" wide scan Field of view along slit164" (north-south direction) Spatial scan range±164" Slit width0.16" Spectral coverage630.08nm - 630.32nm Spectral resolution27mÅ / 21.53 mÅ sampling Measurement of polarization Stokes I,Q,U,V simultaneously with dual beams (orthogonal linear components) Polarization signal to noise10 3 (with normal mapping)

22. 22 EIS (360”x512”) XRT (2048”x2048”) E W S SOT:NFI/SP (328”x164”) SOT: BFI (205”x102”) N Solar-B Fields of View SOHO/EIT FeXII 195A

23. 23 327.7”CCD of NFI / SPG scanning Vignetting by tunable filter 183.2” 163.8” Field stop at f2,  ” x 197.4” or 7.93 x 4.33 mm 2 @f2 HDM hole,  505” or 2.864mm @f1 16.8” or 0.37mm @f2 52.5” or 0.3mm @f1 0 % 20 % 40 % CCD of BFI

24. 24 Schematics of the SOT polarimeter Pupil image HDM Polarization modulator unit (PMU) CTM-TM OTA M1 M2 FG/NFI SP FG-CCD SP-CCD left/right SP- Polarization analyzer (beam splitter) NFI- Polarization analyzer Non-polarizing beam splitter Collimator lens unit (CLU) Tunable filter Slit scan mirror Mask wheel Mech. shutter Astigmatism corrector lens (ACL) Reimaging lens Slit Blocking filter wheel

25. 25 Polarization modulator Waveplate: Common for FG/SP (PMU) Continuous rotation, 1.6sec/rot Retardation: N+0.35  @632nm and 517nm Wavelen gth (nm) Retardati on (wave) 517.3 6.682 525.0 6.572 589.6 5.762 630.2 5.344 656.3 5.110

26. 26 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 PMU segment Q U V WP:  PL Polarization modulation

27. 27 16-pos. continuous readout 4-pos. (example) SP, NFI shutterless Mod. cycle = 0.8sec  ε ~ 0.1% Polarization sampling NFI shuttered Mod. cycle > 5sec  ε ~ 0.5%

28. 28 NFI shutterless mode Mask off outer parts of CCD by focal plane mask Continuous readout (10frame/sec) without operating the mechanical shutter On-board demodulation and accumulation to achieve high S/N 16 ” x 163.8 ” 32 ” x 163.8 ” 64 ” x 163.8 ” 128 ” x 163.8 ” 164 ” x 163.8 ” 328 ” x 163.8 ” Size of focal plane mask FG CCD 1024 pix shift = 6.30msec Transfer speed = 6.15  sec/pix 6.30ms/1600ms*360*2 = 2.83 deg. azimuth rotation

29. 29 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)

30. 30 Data rate （ 4k*2k*100/2s ~ 1GB/sec ） Observation planning 10” 100”1000” FOV Time res. 1” 0.1” Spatial res. 1sec 1min Time span 1hr 1day 1week 10sec 1 # of wavelength (reliability) Random noise (detection limit) 1min 1hr 1day 10min 4 2 64 16 0.01% 0.1% 1% 0.2” 0.4” SOT limit SOT limit performance ~10 4 times larger than telemetry limit (0.3Mbps)

31. 31 10” 100”1000” FOV Time res. 1” 0.1” Spatial res. 1sec 1min Time span 1hr 1day 1week 10sec 1 # of wavelength (reliability) Random noise (detection limit) 1min 1hr 1day 10min 4 2 64 16 0.01% 0.1% 1% 0.2” 0.4” Flux tube dynamics: local physical process energy flow into corona 3D dynamics

32. 32 10” 100”1000” FOV Time res. 1” 0.1” Spatial res. 1sec 1min Time span 1hr 1day 1week 10sec 1 # of wavelength (reliability) Random noise (detection limit) 1min 1hr 1day 10min 4 2 64 16 0.01% 0.1% 1% 0.2” 0.4” AR energetics: global energy storage SOT/SP full scan

33. 33 10” 100”1000” FOV Time res. 1” 0.1” Spatial res. 1sec 1min Time span 1hr 1day 1week 10sec 1 # of wavelength (reliability) Random noise (detection limit) 1min 1hr 1day 10min 4 2 64 16 0.01% 0.1% 1% 0.2” 0.4” Origin of mag.field: emerging flux/ internetwork flux disappearance

34. 34 SOT observation table

35. 35

36. 36 Solar Optical Telescope on HINODE 2006.9.23

37. 37