SOLAR-C B案
Solar UV-Vis-NIR Telescope
焦点面観測装置の概念検討
勝川行雄, 末松芳法 (NAOJ)
一本潔 (Kyoto U.)

基本仕様• Telescope aperture– 1.5mφ• Telescope length– Fit within the H-IIA nose fairing• Spatial resolution– 0.1" in UV– 0.16" in Vis/NIR (Diffraction limit of 1.5mφ at 1µm )• FOV– ~200" x 200" to cover a medium size AR• Wavelength coverage– Shortest ~250 nm to observe Mg II h/k.
– Longest ~1100 nm to observe He I 10830.

• I/F between the telescope and the focal-plane instrument– Collimated beam with 60mmφ to relax the tolerance of alignment.

２次元分光の必要性• 彩層における時間変化の速い現象があらゆる場所で観測される– V> 50km/s (sometimes 100km/s). 音速(~10km/s)よりもはるかに高速.

• 変化の速い現象を観測するためには、１スリット分光はもはや不十分– 100 km/s (velocity) x 300 sec (duration) ~ 30,000 km (~40”)– スリットスキャンに要する時間は約2000 sec。現象の持続じかんよりはるかに遅い。
40" (FOV) / 0.18" (slit step) x 10 sec (integration at each step) ~2200sec• SOLAR-Cでは２次元的な分光の実現が望まれる。いくつかのオプションについて検討– Multi-slit– Double pass spectrograph• Slot spectroscopy with medium wavelength dispersion– Integral field spectroscopy• Fiber-optics bundle or image slicer– Tunable filter-type instruments with rapid wavelength tuning• Fabry-Perot or Lyot

Limitation in the wavelength coverage
MgII h/k•

Mirror reflectivity– Al coating is required to reach
the wavelength shorter than300nm.
– Al+MgF2 coating can reach
110nm.

MgII h/k•

Optical materials (for lensesand coatings)– There are few glass materials
available under 200nm.

He I 10830

Block diagram of the optical conﬁguration
UV/Vis/NIR spectrometer

Telescopep. modulator

spectrometerDetector

Vis/NIR narrowband imager
narrow-band filter

Detector

Vis/UV broadband imager
broad-band filter

DetectorPixel size and FOV of the mission instruments
UV-Vis-NIR telescope

UV/EUV imaging
spectrometer
X-ray telescope

FOV

Pixel size

Exposure

Note.

Broadband

164" x 164"0.04"

< 1sec• 2.5 pix sampling of 0.1" res.
• 4Kx4K detector

Narrowband

246" x 246"

0.06"

< 1sec• 2.5 pix sampling of 0.16" res.
• 4Kx4K detector

Spectrometer246" x 246"

0.06"

1sec
(S/N~1600)• 2.5 pix sampling of 0.16" res.
• 4K pix along slit

0.12"

10sec
(S/N~104)

Spectrometer

1024"x 1024"

0.5"

0.5sec (AR)
5sec(QS)• 0.5"pixel size
• 2Kx2K MCP+CMOS detector

NIImaging

410"x410"

0.1"

1sec (AR)10sec (QS)

• High res imaging with NI telescope• 4Kx4K detector

GIImaging1024"x1024"

0.5"

1sec

Photon count1024"x1024"

2.0"

60sec

• Imaging spectroscopy with GI• 2Kx2K CMOS detector

Transition region

106K

Photosphere

Chromosphere

CoronaCIV

Lyα

Temperature

He I 10830A

105K

Mg II h/k
HINODE/BFI

UV/EUV spectrograph

Ca II H/K
Ca II 8542Å
HαMg I b
Na I D1/D2

104K

Fe I
HINODE/SP

100

HINODE/NFISOLAR-CUV-Vis-NIR telescope
10000

Height (km)Preliminary choices of spectrum lines(deluxe conﬁguration)
Instrument

Spectrum line

wavelength Purpose

Vis/UV broadband imager

UV continuum~250nmHigh res. Img of photospehre

Mg II h/k

280nm

High res img of chromosphere

CN band

388nm

Granules and magnetic elements

G-band430nm

Granules and magnetic elements

Mg Ib2512nm

Low chromosphere V and B

Fe I525 or630nm

Photosphere B

Na ID1/D2

589nm

Low chromosphere V and B
High photosphereHα656nmHigh chromosphere V

Ca II IRT

854nm

High chromosphere T, V and B

Mg II h/k280nm

High chromosphere T and V

Ca II IRT

854nm

High chromosphere T, V and B

He I

1083nmHigh chromosphere V and B

Vis/NIR narrowband imager

UV/Vis/NIR spectrometer

Broadband imager layout• Similar design with the HINODE broadband filter imager (BFI).
• The rotating shutter is located near the focal plane• 0.04"/12µm pix, 4Kx4K→ f ~ 2470mm (F/41)→ FOV 164"
pupil

reimaging lens

field lensfilter wheel

60

4990

700

relay lens

shutter

1650

detector

28

800

1110

Spectrograph layout• Littrow spectrograph design similar with the10830/8542
HINODE spectropolarimeter (SP)detector• Multiple detectors for observing multiple
p. analyzer
spectrum lines
blocking filter• 0.06"/12µm pix, 4K (along slit)
2800 detector→ f ~ 1650mm (F/28)
blocking filter→ FOV 246"
pupil

reimaging lensoffsetparabolaslit

p. modulator
70
60

90230

grating

700

1650

blaze angle

56°groove

80lines/mm

1650λOrderdispersion2800A

73

7.0mÅ/12µm

8542A

2421mÅ/12µm

10830

1927mÅ/12µm

Narrowband imager layout• Telecentric configuration to have uniform wavelength over FOV.
• Large F (F>150) at the Fabry-Perot etalon.
• The shutter is located near the exiting-pupil.
• 0.06"/12µm pix, 4Kx4K→ f ~1650mm (F/28)→ FOV 246"
pupil reimaging lens

700

telecen lensfilter wheel

p. modulator

60

field lens90

detector
relay lens

FP72

1320

telecen lens

shutterp. analyzer

220

720

1000

1000

1500

500

Tentative requirements on TF 	- Wavelength range- band width (FWHM)- Strehl- FOV- free spectral range- tuning range- tuning speed- tuning resolution- repeatability- uniformity
wavelengthtransmission- stability
wavelengthtransmission (flat)- Parastic light- GhostTBD (a possibility 5000 – 8700A)~100mA (50~70mA)>0.9~200 arcsec w/φ1.5m (TBR)>5A+/- 5A
<50ms
<5mA
<2mA
5mA (TBD)
5%5mA /day
1% /day<2%<1%

Choice of tunable ﬁlter
Lyot	  ﬁlter	  	   	  SOUP
Hinode SOT	  vs.	  	   	  	  Fabry	  Perot	

地上望遠鏡による高解像度撮像分
光観測において近年大きな成果をあげてきたLyot filter

Fabry Perot

Speed of incident beamF˜ 40

F ˜ 200 (air space)

Necessary diameter of filter(D=1m, FOV=3ʼ)

˜40mm

˜180mmTransmission

˜ 5%

˜ 70%

Simultaneous 2-polarization

impossible

possible

Simultaneous multi wavelen(in principle possible)

impossible

Structure

ComplexHigh accuracy

Oil

NecessaryFree

Control device

Rot. waveplate or liquid
crystalPiezo or LiNb

Past experience

SOT/Hinode

LASCO C1/SoHO- Contact of opt. elem.s(avoiding bubble)- Mounting calcites- Outgas- Calcite availability-- Mount and control for highaccuracy surfaces(thermal/mech. stress)- Endurance of coating- Stability of inhomogeneity-

ConcernFilter	  diameter,	  Lmin	  =	  image	  size	  =	  F*D*(W/60/180*π)	  =	  0.0003*F*D*W	  	  	  	  (cm,	  	  Telecentric)	  D:	  aperture,	  cm、 W:	  FOV,	  	  arcmin、 F:	  	  F-­‐raLo	  Rough layout in the focal-plane package

500

~3000

1000

1650

500

Broadband imager
~1400

1000

~2500

Spectrograph

Narrowband imager

800

まとめ• 科学的要求に基づく観測すべき彩層ラインの優先度決定はサブWGにて完了している。
• 1.5mΦ口径の望遠鏡性能を最大限引き出すためには、焦点面装置の大型化は避けられない。
(ひので SOT/FPPの約２倍の大きさ)• 要素技術の実現性の見通しを立てること– Large format Fabry-Perot, Lyot filter– 2D spectroscopy for space instruments