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The SPICA Coronagraph Project A BE 1 /E NYA 2 /T ANAKA 2 /N AKAGAWA 2 /M URAKAMI 1 N ISHIKAWA 1 /T AMURA 1 /F UJITA 3 /I TOH 3 /K ATAZA 2 /G UYON 4 AND THE SPICA W ORKING G ROUP 1 National Astronomical Observatory, Mitaka, Japan 2 Institute of Space and Astronautical Sciences, Sagamihara, Japan 3 Kobe University, Japan 4 Subaru telescope/NAOJ, Hilo, Hawaii TPF Workshop, Pasadena, Sept. 28 th -29 th 2006 Email to: abe@optik.mtk.nao.ac.jp
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ABE Lyu, NAOJ, TPF-WS, September 28 th 2006 2 The SPICA Mission in Brief SPICA Coronagraph Requirements Laboratory Demonstration
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3 S PICA M ISSION 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 SP ace I nfrared telescope for C osmology and A strophysics Succes of Akari (Astro-F) launch on Feb. 22nd 2006
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4 T HE S PICA T ELESCOPE 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
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5 S PICA C ORONAGRAPH R EQUIREMENTS 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)
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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 ) C HECKERBOARD M ASKS: A T RADEOFF Tradeoff between complexity/performance Good baseline/backup solution for SPICA
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Asymmetrical checkerboard mask (Tanaka et al.) 7 C HECKERBOARD M ASKS: A T RADEOFF 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
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8 L ABORATORY E XPERIMENT (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
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9 M ANUFACTURING 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)
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10 40µm M ANUFACTURING 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. 27 th 2005)
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11 M ANUFACTURING Mask2 Mask defects No central obstruction design IWA=3 / OWA=30 / Design Cont.=10 -7
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12 P ERFORMANCE (I) Mask1: IWA= 7 / OWA= 16 / Design Cont.= 10 -7 / Throughput= 16% 10 /D with “ photon blocker ”
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13 P ERFORMANCE (II) Mask2: IWA= 3 / OWA= 30 / Design Cont.= 10 -7 / Throughput= 24% 10 /D
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14 P ERFORMANCE (III) (Profiles along the diagonal direction) Average contrast 2.7 10 -7 3 level (speckles) 6.6 10 -7 Average contrast1.1 10 -7 3 level (speckles) 3.3 10 -7
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15 A NALYSIS Theoretical pattern From optical aberrations (from beam line, not from mask) 10 /D Enya et al. astro-ph/0609646
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16 Checkerboard Masks Submitted paper on WF correction requirements (Tanaka et al.) Next planned mask 10 10 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 O NGOING & F UTURE PLANS
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