<title>Proton-induced radiation effects on optical glasses</title>

Abstract

Proton induced absorption over the 350 nm to 2500 nm spectral region and the growth of that absorption with increasing dosage was determined for four glasses (Schott glasses FK3, SF57, IRG7, and Corning Glass Works fused silica 7940). For FK3 and SF57 we can compare the proton induced absorption with x- ray induced absorption. We found protons induced less absorption than x rays for comparable doses by a factor that depended on the glass. Annealing effects with time were also observed. The results indicate that reliance on x ray or electron dosage data overestimates the amount of induced absorption that will occur under realistic orbital conditions where protons dominate the dose. We also searched for proton dose induced index of refraction changes in the glasses, and were able to place an upper limit on the change in n of 10<SUP>-4</SUP>. This shows that a prism spectrometer is a feasible candidate for spaceborne observations. The absorption in a holmium oxide filter glass and an optical cement also was characterized.