Critical emission of two-dimensional electrons from a dielectric into vacuum induced by a nanosecond dense electron beam injected in the specimen

A theoretical model has been developed which describes the critical electron emission from a dielectric that is induced by an injected nanosecond-duration electron beam of moderate or high density. A numerical realization of the model has been constructed which describes the principal properties of the emission: the onset of the phenomenon as the density of the charge injected in the specimen reaches a certain value; the delay of the emission pulse relative to the exposure pulse, which may be as long as several tens of nanoseconds; the emission coefficient reaching unity, and the spatial nonuniformity of the emission.