POTASSIUM MIGRATION IN SILICA GLASS DURING ELECTRON-BEAM IRRADIATION

Potassium glass was irradiated by 10, 30 and 50 keV electron beams of various diameters and the time decay of potassium x-radiation was meas ured. These measurements were complemented by SEM observation of the e tched cross sections of exposed areas and potassium depth concentratio n profiles in order to observe structural changes in the glass. Whilst the temperature increase remained low, the length of the incubation p eriod was inversely proportional to the specimen current density and a possible explanation of this phenomenon was suggested.