X-Irradiation of Fused Silica

Abstract

IN experiments which involved the exposure of fused silica to X-rays, it was observed that the fused silica discoloured. The colour was a very dark violet, and disappeared on heating. The silica was of the clearest and most homogeneous optical quality and presumably very pure. We thought it conceivable, therefore, that the coloration might be due to a reduction of silica to silicon and, since silicon is an excellent reflector in the ultra-violet, that the discoloured irradiated surface might reflect better in the ultra-violet than an unirradiated surface.