It was recalled that electron-irradiated alkali ion-containing glass suffered changes in structure. During irradiation, the exposed volume of the glass changed rapidly, and this was reflected by a rapid decay of the alkali X-ray intensities. Such decay normally followed after an incubation period which depended upon the characteristics of the electron-probe. The incubation periods and the slopes of the decay curves were here determined experimentally, and a model which explained the observations was developed. Bombardment with high-energy electrons caused the production of doubly-ionized alkalis. This new species of alkali was then accelerated by the electric field which was created by the electron beam. Spontaneous migration began as soon as the numbers of released alkalis reached a critical percolation point. The new activation energies, percolation thresholds and effective ionization cross-sections at the percolation point were calculated by means of the above model.

Fast Migration of Alkali Ions in Glass Irradiated by Electrons. O.Gedeon, K.Jurek, V.Hulinsky: Journal of Non-Crystalline Solids, 1999, 246[1-2], 1-8