Analytical formula for multiple ionization cross sections of rare gas atoms by electron and positron impact

Abstract

The paper presents an analysis of data on the single and multiple ionization cross sections of rare gas atoms by electron impact and single ionization cross sections by positron impact. To approximate the cross section for single ionization of atoms of rare gases, as well as a large number of atoms of other elements, a semi-empirical formula with four parameters was proposed, which gives an accuracy of several percent in a wide energy range. Here we generalize our approach to the case of multiple ionization of an atom by electron impact and single ionization by positron impact. For the selected sets of experimental data, approximation coefficients are calculated. The approximation formula reproduces the values of the ionization cross sections for rare gases in a wide range of energies with an accuracy of the order of error of the available experimental data.