
Author(s):
V.P. Shevelko, H. Tawara and E. Salzborn

Title:
MultipleIonization Cross Sections of Atoms and Positive Ions by Electron Impact
Date of publication:
July 1995

Key words:
atomic coIIisions, ionization potential, multiple electron ionization, effective cross section

Abstract:
For the first time, semiempirical formulae for muItipIeionization (MI) cross sections sigma_n of atoms and ions by electron impact are suggested for ejection of three or more electrons n geq 3. The formulae have been deduced on the basis of available experimental data on sigma_n and the assumption of the BornBethe dependence of sigma_n on the incident electron energy E. A comparison o f the cross section described by the semiempirical formula suggested with experimental data available for neutral atomic targets from Ne up to U and ejection up to 13 electrons and with those for positive ions from Ar^+ up to W^4+ with ejection up to four electrons shows that the formulae can be used for estimation of MI cross sections sigma_n, n leq 3, from threshold up to high electron energies E approx 10^5 eV for an arbitrary atomic or ionic target.

