SECONDARY ELECTRONS FROM CHARGED-PARTICLE COLLISIONS WITH ATOMS AND MOLECULES

Since a large fraction of the energy transfer in energetic atomic collisions is in the production of secondary electrons, most of the radiation effects are a result of this process. Therefore, a knowledge of the energy spectrum (and for some purposes the angular distribution) of secondaries is crucial in understanding the interaction of charged particles with matter. Semi-empirical models for the differential cross sections for secondary electron production by proton and electron impact on atoms and molecules have been developed which summarize a large amount of information in the form of analytical equations with a few parameters for each target species.