Observation of radiation damage in silica glass using ion-induced luminescence

Abstract Optical, electrical, and thermal properties of silica glasses to be used as optical or insulating materials in fusion reactors will be degraded by energetic particle and/or photon irradiation. Degradations arise from atomic displacements and electric excitations by the irradiation. Excitations occurring only during irradiation require in situ observation. In silica glasses, it is well known that ion irradiation produces oxygen vacancies (E′ or E″ center) by atomic displacement, which results in ion-induced luminescence (IIL) assisted by the electron excitations. However, details of IIL are not well understood. This work discusses the results of detailed IIL measurements and the origin of luminescence, taking into account the effects of electron excitation and atomic displacement.