Current Status of SPICA FPIMechanical I/F & resources

April 6th 2010

Hideo Matsuhara (ISAS/JAXA) & FPI team

SPICA FOCAL PLANE INSTRUMENTS - OVERVIEW

Japanese, Korean, European

MIRACLE (Mid-InfRAred Camera w/o LEns)

MIRACLE is a mid-IR instrument with imaging and low-resolution spectroscopy consisting of two channels:

• Filter-wheel : imaging band (R~5) & spectroscopy with grism/prism (R~100)

2K x 2K

Now 5’x5’ is baseline

MIRMESMid-IR Medium-resolution Echelle Spectrograph

ARM-S 　 ARM-L

array format Si:As (2k x 2k) 25 mm/pix

Si:Sb (1k x 1k) 18 mm/pix

Wavelength coverage 10.0mm-19.9mm 19.9mm-35.0mm

Spectral resolution (R=l/Dl) ~1400 ~750

pixel scale 0.409 (“/pix) 0.413 (“/pix)

Slit width 1”.7 (4.2pixel) 2”.5 (6.1pixel)

FOV size 12” x 8”.5 14” x 12”.5

Arm-S Echelle order lmin (mm) lmax (mm)

4 15.53 19.97 5 12.71 15.53 6 10.75 12.71 7 (9.98) 10.75

※ lmin and lmax are defined as the wavelength at which the grating efficiency drops to 40% of the peak

Arm-L Echelle order lmin (mm) 　 lmax (mm)

5 29.4 35.0 6 24.4 29.4 7 21.2 24.4 8 (19.9) 21.2

MIRHESMid-IR High-resolution Echelle Spectrograph

Japanese-led ( Univ. Tokyo/ISAS ） Detector array : 2Kx2K Si:As IBC Immersion Grating for L-mode is very difficult with

the material high-blaze grating(~30cm long)

Short(S)-mode Long(L)-mode

Wavelengths 4 – 8mm 12 – 18mm

Spectral Resolving Power (R=l/ )Dl

30,000 20,000 – 30,000

Slit width 0.72” 1.20”

Slit length 3.5” 6.0”

Disperser ZnSe Immersion GratingHigh-blaze reflective

Grating

Cross-disperser Reflective Reflective

FPC-G, 　 FPC-S Leaded by KASI, Korea

FPC-G Specification (goal) Notes

waveband I-band preliminaryDetector InSb 1024 x 1024

FOV 5’ x 5’ To obtain sufficient # (>10) of guide stars

Output interval 1Hz Typical - trade-off with 0.4HzSensitivity

(25σ) 18.6 mag (AB) Defocused to measure the

centroid in 0”.05 accuracy

FPC-S Specification (goal) Notes

Wavelength

0.8 － 5mm 10pos. Filter wheel (JHKLM & LVF)

Spectral Resolution

～ 50 With LVF, and spatial slow-scanning

Detector InSb 1024 x 1024 FOV 5’ x 5’ 1 pix = 0.3 arcsec

Sens.(3σ) Imaging 26.3 mag(AB) Spectroscopy 6.84x10-20l-1W.m-2

100sec integration( :l mm)

SCISPICA Coronagraph Instrument

A mid-IR coronagraph instrument with both imaging & low-res. spectroscopic capability.

Major goal : direct imaging & spectroscopy at 3.5-27mm

Coronagraph method Binary-shaped pupil mask (baseline) Contrast > 10-6

Field of View: 1.0 x 1.0 arcmin2

Spectral resolution : 20-200

Current status : Draft optical, structure design finished improved Tip-tilt design

SAFARI SPICA Far-infrared

Instrument

Leaded by SAFARI consortium in Europe Imaging Fourier-transform spectrometer

covering 35-210mmFOV : 2 x 2 arcmin2

Wavelength resolution 2000 at 100 mm is maximum

SAFARI Design @Phase-A1 conclusion

Current cold mass : 38.8kg (22% margin to 50kg allocation)

FPI resources / Interface issues

FPI Cold Volume

FPIA = FPI + IOBAIOBA = IOB + PoM (+ 5K shield…)

IOB : instrument optical benchPoM : Pick-off Module

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Critical I/F issues on FPIA

Stringent stiffness requirement of FPIA 150Hz (Z) / 100Hz (X, Y) !! The original concept of IOB plate (ribbed Aluminum plate) itself

does not satisfy the requirement. To overcome the above problem, two options:

[Option A] IOB made of SiC (or CFRP) [Option B] MIRACLE (& MIRMES, MIRHES) base plate will be

a part of the IOB structure (made of Aluminum)

FPI Assembly / Integration: need of Common Pick-off Module (PoM) separated from each FPI, but mechanically I/F to IOB PoM is a sub-system of IOBA No moving parts

Concept of common PoM

Pick-off location is 100-150mm below the surface of IOB, so the PoM looks like a cylinder?

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FPI footprint on IOBEnvelopes of FPIs are now OLD

IOB & FPI structure study – under progress..

Field-of-Views (updated 11 Mar. 2010)

3D Optical config. with New SCI (green)

SCI

FPC-SMIRACLE-short

MIRACLE-long

FPC-G

SAFARI

FPI Cold Mass Allocation

FPIWeight

(kg)comment

MIRACLE

60.0

with 20% margin

MIRMES

MIRHES

SCI 30.0 FPC 10.0 SAFARI 50.0 US-lead instrument

30.0 (optional FPI)

IOB, FPI cover 50.0 with 20% marginTotal 200 excluding US instr.

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Cold stage heat generation

Assumption: Baseline : No parallel mode Any observations will be executed by using single

FPI, excluding FPC-GCurrent Status

<15mW ＠ 4.5K for any observation modeExceeds 5mW@1.7K (baseline allocation

for 1.7K stage) but less than 10mW

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Heat load (max/average) @4.5K stage (09/12/28)

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Heat load (max/average) @1.7K stage (09/12/28)

Warm Electronics I/F

Located at Bus system Total Weight: 120kg, incl. 20% margin

Electric Power (=heat dissipation) Total 199W with maturity margins

ICS-FPI

ICS (interface control specification) document should be prepared for SRR Operation mode & Observing Mode definition I/F with STA (mechanical/optical), CRYO (thermal), BM

(bus module: electrical), AOCS (pointing control I/F) Also resources for warm electronics

MIRACLE, MIRMES, MIRHES,SCI, (& FPC) will be put in ICS-FPI

For US-lead instrument, resources & I/F are described in ICS-FPI (part A)

Dedicated ICS for SAFARI (& FPC)