Influence of ion implantation and electron pre-irradiation on charging of dielectrics under electron beam irradiation: Application to SiO2

We present the experimental study on the effect of preliminary ion and electron irradiation on charging kinetics of SiO2 (quartz) under medium-energy electron beam. It is shown that the charging kinetics differs for SiO2 samples implanted by ions of various chemical natures and by electrons of different energy. It is found the enhancement of charge spreading over the quartz surface pre-irradiated by electrons as a result of desorption of oxygen atoms from the surface. The charging surface potential under electron beam increases more slowly, but to higher values, than in the case of non-irradiated crystals. The observed difference of the steady state values of charging surface potential as a function of incident electron energy is explained for the case of proton pre-irradiated targets.