Secondary electron emission from beryllium under electron and proton bombardment at keV energy

A direct Monte Carlo simulation is developed for the study of the electron- and proton-induced secondary electron emission from beryllium at keV impact energy. The probability for the excitation of an electron within beryllium by primary electron (proton) decreases (increases) with increasing impact energy. The majority of secondary electrons emitted from a beryllium surface is produced through an electron-cascade process of the excited electron. Electron emission statistics (i.e., the probabilities for a given number n = 0, 1, 2,... of emitted electrons) apparently deviate from the Poisson distribution. For electron bombardment, enhanced cascade generation of secondary electrons results in greater deviation than that for proton bombardment, in addition to small deviation due to the backscattering of the projectile. (author) 55 refs