Development of High-Quality Light-Weight Mirror for thr Space-Borne Cooled Infrared Telescope

天载冷红外望远镜高质量轻质反射镜的研制

• 批准号: 06559004
• 负责人: ONAKA Takashi
• 金额: $ 7.04万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06559004/
• 关键词: cooled telescope; infrared observation; light-weight mirror; space-borne instruments; silicon carbide; space observation

We fabricated a spherical mirror of 150mm in diameter, which was made of SiC (silicon carbide) as a test mirror for the space-borne light-weight cooled telescope for the infrared use. The optical tests of the mirror indicate the distortion of the mirror at low temperatures (<200K). The amount of the distortion was, however, 0.6mum peak-to-valley at most, and we attributed it to the bi-metal effects produced by the difference in the thermal contraction between the CVD SiC on the surface and the porous SiC of the core. We did not detect very large distortions due to SiC material itself, which shows a quite contrast to the metalic mirrors. The porous SiC has a specific weight of 2 g cm^<-3>, which is quite advantageous for light-weight mirrors of space-borne telescopes. The CVD SiC is required to obtain high-quality polishing. The distortion was reproducable and we concluded that it could be reduced to a negligeble level if we could have a sufficient accuracy in figuring the SiC blank of the mirror. The present investigation showed that SiC mirrors are very promising for the light-weight mirror for space-borne cooled telescopes in future, but we still need to improve the blank processes to achieve the goal.

我们制作了直径150mm的SiC（碳化硅）球面镜，作为星载红外轻型冷却望远镜的测试镜。镜子的光学测试表明镜子在低温（<200K）下会发生畸变。然而，畸变量最多为 0.6μm 峰谷，我们将其归因于表面 CVD SiC 与芯部多孔 SiC 之间的热收缩差异产生的双金属效应。我们没有检测到碳化硅材料本身造成的非常大的扭曲，这与金属镜形成了鲜明的对比。多孔SiC的比重为2g cm^-3，对于星载望远镜的轻质镜面来说是相当有利的。 CVD SiC 需要获得高质量的抛光。畸变是可再现的，我们得出的结论是，如果我们能够足够准确地计算反射镜的 SiC 毛坯，则畸变可以降低到可以忽略不计的水平。目前的研究表明，碳化硅反射镜作为未来星载冷却望远镜的轻质反射镜非常有前景，但我们仍然需要改进毛坯工艺来实现这一目标。

项目成果

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I.Yamamura 等人：“IRTS 点源的中红外光谱观测”Publ.Astron.Soc.Japan.48。

T.Onaka et al.: "Detection of the Mid-Infrared Unidentified Bands in the Diffuse Galactic Emission by the IRTS" Publ. Astron. Soc. Japan. 48. L59-L63 (1996)

T.Onaka 等人：“IRTS 检测漫射银河发射中的中红外未识别波段”Publ。

T.Onaka: "Polarization of Thermal Emission from Aspherical Dust Grains in an Anisotropic Radiation Field" The Astrophysical Journal. (印刷中). (1995)

T. Onaka：“各向异性辐射场中非球面尘埃颗粒的热发射的偏振”《天体物理学杂志》（1995 年出版）。

H. Murakami, et al.: "The Infrared Telescope in Space(IRTS)" The Astrophysical Journal. 428. 354-362 (1994)

H. Murakami 等人：“太空红外望远镜 (IRTS)”《天体物理学杂志》。

H.Murakami et al.: "Flight Performance of the Infared Telescope in Space" Proc.of Soc.Photo-Opt.Instr.Eng.2744. 68-74 (1996)

H.Murakami 等人：“红外望远镜在太空中的飞行性能”Proc.of Soc.Photo-Opt.Instr.Eng.2744。