Microscopic description of proton induced electron emission from insulators: Comparison between alumina and aluminum targets

It is well known that the electron emission yield from insulators is larger than from metals. Most of the previous works on electron emission have been on metals, and very few works have been done on insulators, either experimentally or theoretically. We present in this paper a microscopic description of proton induced electron emission from alumina. Elastic and inelastic interactions for the incident protons and excited electrons are considered as well as the charging-up of the target. The characteristics of proton induced electron emission from alumina (especially the yield gamma) are calculated by a Monte Carlo simulation method. A comparison with aluminum targets is done, especially with respect to the influence of the electron inelastic mean free path and of the work function.