SEQUENTIAL-LAYER ENERGY-TRANSFER FROM PULSED ELECTRONS TO A LIF SINGLE-CRYSTAL

The buildup of the population of self-trapped excitons, at various dep ths beneath the surface of an alkali halide crystal irradiated with hi gh-energy pulsed electrons of 20-ps half width, represents sequential energy transfer from one layer to another, owing to secondary electron s released by the primary ones. Hence it is possible to observe sequen tially the spatial profile of a quantity proportional to the different ial energy transfer from the secondary electron shower at each depth o f a sample.