Analytical partitioning of total cross sections for electron scattering on noble gases

Abstract

Empirical analytical formulae are proposed, aiming at the description of partial cross sections for electron scattering on noble gases. Selected measurements of total, excitation and ionization cross sections for these gases have been fitted by these analytical formulae in the 20-5000 eV energy range. The elastic cross sections, obtained as the difference, compare quite well with the elastic experimental data for all gases but for helium. The difference elastic cross sections were fitted by a cross section formula derived from electron scattering on a single or double Yukawa potential in the first Born approximation. Our analysis shows a good consistency between partial and total cross sections for the four heavier gases. For helium, we suggest the possibility of large errors in the high energy part of total, elastic and excitation cross sections. The analytical expressions given in this paper allow to reproduce the total and partial cross sections within the measurement errors in a large energy range from a few tens of eV, up to several keV.