Europa Imaging System Wide Angle Camera The Effect of Gamma Radiation on the Refractive Index and Transmission of Radiation Resistant Glasses

摘要

The impact of gamma radiation on refractive index and transmission was analyzed for several glasses. The goal of the analysis is to quantify the optical performance impact of Jovian electron and proton radiation environments using gamma radiation as a proxy for the Europa Imaging System (EIS) Wide Angle Camera~1 (WAC) refractive telescope. The testing was split into two sample sets. The first set of glasses tested are baselined in the current WAC design: BK7G18, Calcium Fluoride, Fused Silica, and LF5G15. Analysis demonstrates no significant change in the refractive index or transmission in BK7G18, Calcium Fluoride, Fused Silica, and LF5G15 when exposed to 1 Mrad of gamma radiation. The second set of glasses tested was two i-line and two radiation resistant glasses from Ohara. Analysis demonstrates no significant change in the refractive index in BAL35Y, PBL25Y, S-BAL25-R, and S-BSL7-R when exposed to 1 Mrad of gamma radiation. Significant loss in transmission was observed for the two i-line glasses (BAL35Y and PBL25Y) when exposed to 1 Mrad of gamma radiation.