Electrization of the quartz glass surface by electron beams

To establish the effect of subthreshold defect formation on the charge accumulation in quartz glasses, a comprehensive study of the process of their electrization by electron beams was carried out. Earlier it was shown that the process of radiative electrization of quartz glasses consists of two stages. The short-term stage of charging can be explained by the accumulation of charge on the initial trap centers, and the long-term component can be caused by the generation of deep trap centers capable of capturing electrons. In the studied quartz samples, the trapping centers can be three-coordinated silicon atoms ($E'$-centers). The presence of two stages of the charging process is confirmed by two different methods for determining the surface potential. Despite the increase in the surface potential during irradiation and the resulting decrease in the energy of the incident electrons, an increase in the intensity of the cathodoluminescent signal is observed. Such an increase in intensity can be caused by an increase in the number of luminescent defects in quartz, a two-coordinated silicon atom or a non-bridging oxygen atom, as well as by charge accumulation at competing nonradiative trap centers.