Binding Effect Corrections in the Energy-Loss Distribution Functions for Charged Particles Passing through Thin Absorbers

Abstract

In the theoretical treatment of the statistical fluctuation in energy-loss of charged particles passing through thin absorbers, terms which are of the order of the electron binding energy are ordinarily neglected. The corrections required, when this is no longer justified, are discussed in particular reference to the development by Symon, which has as its limiting cases the Gaussian distribution derived by Bohr, and Landau's distribution. Formulas are presented which give the correction for each of the three weighted parameters appearing in Symon's derivation. The corrected parameters can then be used in conjunction with Symon's curves to obtain the energy-loss distribution appropriate for a given set of conditions. An illustration is presented for the cases of 5-Mev protons and 5-Mev alpha particles.