2009年8月11日 東谷

参考文献
・NIRCam Instrument Optics,  Huff et al. (SPIE 5904-04)
・NIRCam Filter Wheels, McCully et al. (SPIE 5904-11)

WISH Filter Wheel
1段4ポジション×2段の場合(フィルタは6枚)
JWST/NIRCam Filter Wheel JWST/NIRSpec Filter Wheel
Number of Positions 8 (4 positions x 2 wheels ?) 24 (12 positions x 2 wheels)
Pupil Wheel(PW): wave-front-sensing elements,filters,weak lenses
Wilter Wheel(FW):4° tilteted
8 broad-band
12 intermediate
9 Narrow-band
NIRcam Filters Sensitivities
8
3 longpass filters
3 broad-band filters
1 CaF2 Plate as clear aperture
1 Shutter/Diffuser component
Filter Material Si ? CaF2, BK7
Filter Diameter, Thickness Φ140 mm Φ 48 mm, t=5mm(FW),10mm(PW)
Wheel Diameter Φ440 mm Φ290 mm Φ307 mm
Total Mass 350gx6=2100g(Si Filters)+
6300 g (Filter Wheel Structure) +
6500 g (Mechanism Support) +
2250 g (Filter Wheel Structure) +
350 g (Other)=
9100 g
Static Qualification Load 30 G
Material MS: Ti-6Al-4V
FWS: Al5456
Motor Custom rotor, d=3.6" 3-phase,
brushless DC motor
130mA(high torque const.)
Bearing duplex bearing
35mmOD and 17mmID
dry-film lubricated cage
Operating Temperature 32-37 K
(Survival Temp.=20-330K)
Position Sensing inductive sensors
Test Thermal cycles,
Operation 2400 revolutions at 20K
Optical Requirement Surface Figure <λ/10 P-V*0.022&;lambdarms)@λ=633nm
Scratch/Dig=40/20
Surface Roughness <20Årms
Dimensional Tolerance=±0.05mm
Edge and chamfers=Polished or acid-etched
Memo 較正用光源も一緒にマウントされている