Gamma irradiation induced defects in different types of fused silica

In this work, KU1 and KS-4V silica glasses, considered as the main candidate materials for optical diagnostic and remote handling components in ITER, have been gamma irradiated at doses from 10 kGy up to 12 MGy together with five commercial types of silica. After each irradiation the optical absorption of the different grades has been obtained, and the concentration evolution of each defect has been compared for the different silica types. This comparison allowed us to determine which defects are intrinsic and which depend on the impurity level or fabrication method. The results allow one a better understanding of the relevance of the precursors present in the different silica grades. (C) 2008 Elsevier B.V. All rights reserved.