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The SPICA Coronagraph Project
ABE1/ENYA2/TANAKA2/NAKAGAWA2/MURAKAMI1
NISHIKAWA1/TAMURA1/FUJITA3/ITOH3/KATAZA2/GUY
ON4
AND THE SPICA WORKING GROUP1National Astronomical Observatory, Mitaka, Japan
2Institute of Space and Astronautical Sciences, Sagamihara, Japan
3Kobe University, Japan4Subaru telescope/NAOJ, Hilo, Hawaii
TPF Workshop, Pasadena, Sept. 28th-29th 2006
Email to: [email protected]
ABE Lyu, NAOJ, TPF-WS, September 28th 2006
2
The SPICA Mission in Brief
SPICA Coronagraph
Requirements
Laboratory Demonstration
3SPICA MISSION
mIR to submm astrophysics Complementary to JWST @ >15mic
Coronagraphic mode(proposed by Tamura et al.)
Direct observation of outer self-luminous planets(20~100+ UA orbits)
Goal contrast >10-6 within the exploration area
Benefit from monolithic pupil
SPace Infrared telescope for Cosmology and Astrophysics
Succes of Akari (Astro-F) launch on Feb. 22nd 2006
4THE SPICA TELESCOPE
Telescope diameter
Launch date
Orbit
Wavelength coverage
Cryogenic active cooling
(warm launch)
Pointing accuracy
Tip-tilt jitter control
Wavefront control
3.5 m (SiC)
~2015(HIIA rocket)
Lagrange L2
5-200 µm
4.5K
0.3”
30mas
TBD (corona. related)
SPICA telescope concept
5SPICA CORONAGRAPH REQUIREMENTS
The mIR wavelengths constrains very high angular regions need for smallest possible IWA coronagraphs
SPICA tip-tilt jitter is important (/12@5µm) vibrations of cryo-coolers coronagraph poorly sensitive to TT
SPICA telescope pupil geometry(15~25% central obscuration)
Candidate coronagraphs Binary pupil masks (Kasdin/Vanderbei) – baseline Checkerboard
PIAA (Guyon)
(Multi-stage) apodized pupil Lyot coronagraph (Aime & Soummer)
6
Checkerboard Masks Pros/Cons
High IWA (>5 /D, because of CO)
Low throughput
Discovery space
Low temperature (need 4.5K)
Optical environment complexity
Sensitivity to Tip-tilt
Chromaticity
Aberrations (can be made standalone)
CHECKERBOARD MASKS: A TRADEOFF
Tradeoff between complexity/performanceGood baseline/backup solution for SPICA
Asymmetrical checkerboard mask (Tanaka et al.)
7CHECKERBOARD MASKS: A TRADEOFF Study of asymmetrical configurations (Tanaka et al. PASJ, 58, 627, 2006) lower IWA, extended search area close to axes
Study of OWA vs spatial frequency AO correction range Tanaka et al. 2006, submitted
8LABORATORY EXPERIMENT (Enya et al., to appear in A&A) Conducted in ISAS Environment
Dark room Air flow (on/off) No temperature regulation
Setup Off-the-shelf optics ~ PtV, AR coating No AO system Beam diameter: 2mm (masks side 1.41mm) / F# ~ 600 BITRAN cooled CCD camera (2048×2048)
(10 m diameter)
Enya et al. astro-ph/0609646
9MANUFACTURING Manufactured at the Advanced Institute of Science and Technology (AIST, Japan)
Electron beam patterning and lift-off process (100nm aluminium)
BK7 substrates
1.41 mm side square (2mm diameter pupil)
10
40µm
MANUFACTURING
Designed mask
Mask1: IWA=7 / OWA=16 / Design Cont.=10-7
Checkerboard Mask Prototype
Fabrication process
Performance Modeling
Manufactured by AIST company (Japan – Release date sept. 27th 2005)
11MANUFACTURINGMask2
Mask defects No central obstruction design
IWA=3 / OWA=30 / Design Cont.=10-7
12PERFORMANCE (I) Mask1: IWA=7 / OWA=16 / Design Cont.=10-7/ Throughput=16%
10 /D
with “photon blocker”
13PERFORMANCE (II) Mask2: IWA=3 / OWA=30 / Design Cont.=10-7/ Throughput=24%
10 /D
14PERFORMANCE (III)(Profiles along the diagonal direction)
Average contrast 2.7 10-7
3 level (speckles) 6.6 10-7
Average contrast 1.1 10-7
3 level (speckles) 3.3 10-7
15ANALYSIS
Theoretical pattern
From optical aberrations(from beam line, not from mask)
10 /D
Enya et al. astro-ph/0609646
16
Checkerboard Masks Submitted paper on WF correction requirements(Tanaka et al.)
Next planned mask 1010 design
Limit of optics
Cryogenic AO tests 6×6 channels prototype BMC mirror (modified substrate)
Other investigations Two-Mirror Apodization (collaboration with O. Guyon)
PIAAC
APLC designs
ONGOING & FUTURE PLANS