空间电离辐射对镧系光学玻璃透射率的影响

利用60Coγ射线对镧火石玻璃和镧冕玻璃进行辐照,研究不同辐照剂量对光学透射率的影响及其在空间光学系统中使用的适应性,辐照总剂量最大达到10 kGy。结果表明:所有玻璃在辐照后可见光透射率都下降了,而在近红外波段仍然保持较高的透射率。尽管镧火石玻璃LaF10平均透射率在辐照前最小,但是辐照后LaF10透射率衰减是所有玻璃中最小的。模拟了8个不同轨道高度地球辐射环境10年累积的总剂量以及经过10 mm铝屏蔽后的累积总剂量。发现对于10年任务期,在3 000、6 000和10 000 km轨道需要增加屏蔽层厚度,而在其他5个轨道,10 mm厚的铝屏蔽可以保证镧系玻璃满足系统对透射率的要求。

Effects of Space Ionizing Radiation on Transmission of Lanthanum Glasses

A study of the effects of 60Co gamma radiation on the transmission of lanthanum flint and lanthanum crownglasses was presented for application in space optics. The max total dose attained was 10 kGy, and the experimental resultsshow that the visible transmission for all samples decreases, while the nearinfrared transmission shows a slight decrease.Although the transmission of the lanthanum flint glass LaF10 is the minimum of all samples before irradiation, it also showsa minimum transmittance loss after irradiation. The total accumulated radiation doses with and without a 10 mm thick Al shielded layer are simulated for the eight orbits of different altitudes in a 10 year mission. The simulating results indicate
that in 3 000 km, 6 000 km and 10 000 km orbit altitudes, a thicker shielded layer is required to reduce the total dose,while in the other five orbits, a 10 mm thick Al layer is enough for satisfying the optical system performance.