Nonuniform distribution of absorbed energy in high-resistance materials excited by an electron beam

Experimental results are presented on the changes in the optical characteristics of lithium fluoride induced by an electron beam with time-varying density and pulse energies close to the threshold for destruction of the material. The spatial distribution of color centers is investigated, especially near breakdown channels. Mechanisms for nonuniform accumulation of defects are discussed, along with the fundamental causes of the inhomogeneous energy distributions induced by the high-current electron beam. Concrete results of calculations of the field intensity distribution in LiF crystals during irradiation are presented, based on models of “uniform” and nonuniform charging of the sample. An abrupt increase in the electric field intensity is predicted near the breakdown channel.