A hybrid multiple-scattering theory for electron-transport Monte Carlo calculations

This paper describes a new elastic multiple-scattering theory and its incorporation into the EGS4 Monte Carlo code. The important features of the new theory are: 1) the angular distributions are stable physically and numerically from the no-scattering small electron pathlength limit to the multiple scattering regime where electron pathlengths can be thousands of mean-free-paths long, 2) in the small-pathlength limit, the angular distributions may be made to conform to an arbitrary cross section. The object of this paper is to describe the implementation and show results that demonstrate its stability by comparing with distributions generated from a single elastic-scattering model and by showing convergence of backscatter calculations.