Development of lightweight SiC mirrors for the space infrared telescope for cosmology and astrophysics (SPICA) mission

Kaneda, Hidehiro; Onaka, Takashi; Enya, Keigo; Kataza, Hirokazu; Makiuti, S.; Matsuhara, Hideo; Miyamoto, Masashi; Murakami, Hiroshi; Saruwatari, Hideki; Watarai, Hitoshi; Yui, Yukari Y.

doi:10.1117/12.733430

Cited by 9 publications

(10 citation statements)

References 14 publications

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“…12. The result was obtained by the Institute of Space and Astronautical Science of Japan Aerospace Exploration Agency (JAXA) by measuring the difference in mirror accuracy with a He-Ne laser (632.8 nm wavelength) when the mirror body was uniformly cooled from 300 to 95 K [16]. Wave numbers corresponding to the colors at the center position of the 19 segmented regions were read from the contour bar, and values of the mirror surface deviation of these regions were calculated by multiplying their wave numbers by the wavelength of the He-Ne laser (632.8 nm).…”

Section: F Verification Of the Effectiveness Of The Case Study's Resultsmentioning

confidence: 99%

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Quality evaluation of spaceborne SiC mirrors (I): analytical examination of the effects on mirror accuracy by variation in the thermal expansion property of the mirror surface

et al. 2013

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The Japan Aerospace Exploration Agency has studied a large-scale lightweight mirror constructed of reaction-bonded silicon carbide-based material as a key technology in future astronomical and earth observation missions. The authors selected silicon carbide as the promising candidate due to excellent characteristics of specific stiffness and thermal stability. One of the most important technical issues for large-scale ceramic components is the uniformity of the material's property, depending on part and processing. It might influence mirror accuracy due to uneven thermal deformation. The authors conducted systematic case studies for the conditions of CTE by finite element analysis to know the typical influence of material property nonuniformity on mirror accuracy and consequently derived a comprehensive empirical equation for the series of CTE's main factors. In addition, the authors computationally reproduced the mirror accuracy profile of a small prototype mirror shown in cryogenic testing and hereby verified wide-range practical computational evaluation technology of mirror accuracy.

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Section: F Verification Of the Effectiveness Of The Case Study's Resultsmentioning

confidence: 99%

“…Cryogenic testing on the mirror was conducted to evaluate how a precooled mirror surface changed its mirror accuracy by cooling [16]. Three fiducial points attached on the rim of the mirror surface, as shown in Fig.…”

Section: A Model Mirror Bodymentioning

confidence: 99%

Quality evaluation of spaceborne SiC mirrors (I): analytical examination of the effects on mirror accuracy by variation in the thermal expansion property of the mirror surface

et al. 2013

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“…2. Result of the cryogenic testing of the mirror body [7]. Temperature: 300 K → 95 K. radial direction from each of 19 segmented regions of the mirror surface, and the two measured values were then averaged.…”

Section: Cte Measurement and Analysis Based On The Resultsmentioning

confidence: 99%

“…Cryogenic testing on the mirror surface was conducted at the Institute of Space and Astronautical Science of JAXA, and the result obtained is shown in Fig. 2 [7]. This figure shows the difference in mirror accuracy measured when the mirror body was uniformly cooled from 300 to 95 K.…”

Section: A Mirror Body To Be Evaluatedmentioning

confidence: 99%

Quality evaluation of spaceborne SiC mirrors (II): evaluation technology for mirror accuracy using actual measurement data of samples cut out from a mirror surface

et al. 2013

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The authors studied the quality evaluation technology of a spaceborne large-scale lightweight mirror that was made of silicon carbide (SiC)-based material. To correlate the material property of a mirror body and the mirror accuracy, the authors evaluated the mirror surface deviation of a prototype mirror by inputting actually measured coefficient of thermal expansion (CTE) data into a finite element analysis model. The CTE data were obtained by thermodilatometry using a commercial grade thermal dilatometer for the samples cut from all over the mirror surface. The computationally simulated contour diagrams well reproduced the mirror accuracy profile that the actual mirror showed in cryogenic testing. Density data were also useful for evaluating the mirror surface deviation because they had a close relationship with the CTE.

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“…The current design of the Space Infrared Telescope for Cosmology and Astrophysics (SPICA), a Japan-led international infrared astronomical mission, will use SiC for its 3-m class aperture telescope. The telescope should be operated at below 6 K and have diffraction-limited performance at a wavelength of λ=5 μm [1,2]. SiC is also a candidate material for 2-m aperture optics to be used in future Earth observation missions in visible to infrared wavelengths from a geostationary orbit.…”

Section: Introductionmentioning

confidence: 99%

Optical testing of lightweight large all-C/SiC optics

Suganuma

Imai

Katayama

et al. 2017

International Conference on Space Optics — ICSO 2010

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We carried out various tests of 800-mm-diameter aperture, lightweight optics that consisted wholly of carbon fiber-reinforced SiC composite, called HB-Cesic. A cryogenic optical test was performed on the primary mirror to examine any CTE irregularity as a surface change, and only small deformations were observed. The primary mirror was assembled with a convex secondary mirror into an optical system and tested under vacuum at the 6-m-diameter radiometer space chamber at Tsukuba Space Center of JAXA, where we have prepared interferometric metrological facilities to establish techniques to test large optical systems in a horizontal lightaxis configuration. The wavefront difference between under vacuum and under atmosphere was confirmed to be less than 0.1 λ at λ=633 nm, if we realigned the optical axis of the interferometer and flat mirror under vacuum. We also demonstrated a stitching interferometry using the Φ800-mm optics by rotating a mask wheel of subapertures in front of the optical reference flat. The wavefront stitched from eight individual measurements of Φ275-mm subapertures differs from the full-aperture measurement without the mask by about 0.1 λ nm RMS, which showed the technique could able to be applied to test large telescopes especially for infrared wavelength region.

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Development of lightweight SiC mirrors for the space infrared telescope for cosmology and astrophysics (SPICA) mission

Cited by 9 publications

References 14 publications

Quality evaluation of spaceborne SiC mirrors (I): analytical examination of the effects on mirror accuracy by variation in the thermal expansion property of the mirror surface

Quality evaluation of spaceborne SiC mirrors (I): analytical examination of the effects on mirror accuracy by variation in the thermal expansion property of the mirror surface

Quality evaluation of spaceborne SiC mirrors (II): evaluation technology for mirror accuracy using actual measurement data of samples cut out from a mirror surface

Optical testing of lightweight large all-C/SiC optics

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