γ辐照对空间用光学玻璃透射率的影响

γ-Radiation Effect on Transmission of Optical Glass for Application in Space Optics

利用60Coγ射线对熔融石英、重火石和镧冕玻璃进行辐照,研究其光学透射率的变化及其在空间光学系统中的适用性。辐照后测试光学玻璃的透射率,光谱范围为400～1100nm。测量结果表明,除熔融石英玻璃外,其它玻璃的可见光透射率辐照后均下降。尽管重火石和镧冕玻璃光学透射率在辐照前相似,但辐照后的透射率损耗则不同,镧冕玻璃抗辐射能力更强。对于重火石和镧冕玻璃,未镀膜样品较镀防反射膜样品的抗辐射能力强。研究中观测到,当达到一定辐射剂量后,玻璃材料的透射率不再继续衰减而趋于稳定。这些结果为空间光学系统针对辐射进行冗余设计提供了依据。

The effects for 60Co γ-radiation on the transmission of several optical glass types, fused silica, dense flint and lanthanum crown, were presented for application in space optics. Transmission spectra in the range of 400-1 100 nm were recorded after exposure to various doses of radiation up to 200 kGy. The results show that for all samples except fused silica, the visible transmission decreases. Although the dense flint and lanthanum crown glass are optically similar before irradiation, they show different transmittance loss after irradiation, dense flint radiation. When the dose increases to some exten g t ass having stronger sensitivity to γ the transmittances loss stops decrea sing and becomes steady. In addition, the bare samples are more resistant than those with anti-reflection coatings. Taking these differences into account can help to improve the radiation tolerance of optical system design for space applications.