Relativistic electron-beam-produced plasmas. I. Collision cross sections and loss function in argon

Abstract

The generalised oscillator strength formalism is used to calculate a complete and self-consistent set of collision cross sections for incident electron energies ranging from thresholds up to 10 MeV. Results are reported for about 40 states with an emphasis given on the ionisation processes. The study of the loss function points out the importance of the inner-shell ionisation, which consumes nearly as much energy as the excitation and the ionisation of the outer shell. Moreover, the authors show that the mean energy of the secondaries ejected from a given shell is about twice the ionisation potential of this shell. As a result, many energetic secondary electrons coming from inner-shell ionisation are present in the plasmas produced by relativistic electron beams.