A Monte Carlo investigation of secondary electron emission from solid targets: spherical symmetry versus momentum conservation within the classical binary collision model

TL;DR

This paper compares two Monte Carlo approaches for modeling secondary electron emission from solids, one assuming spherical symmetry and the other enforcing momentum conservation, to understand their impact on energy distribution predictions.

Contribution

It introduces a Monte Carlo scheme that incorporates secondary electron generation with two different angular calculation methods, highlighting the effects of momentum conservation.

Findings

Spherical symmetry assumption violates momentum conservation.

Momentum conservation approach provides more physically accurate results.

Comparison shows significant differences in energy distributions between the two methods.

Abstract

A Monte Carlo scheme is described where the secondary electron generation has been incorporated. The initial position of a secondary electron due to Fermi sea excitation is assumed to be where the inelastic collision took place, while the polar and azimuth angles of secondary electrons can be calculated in two different ways. The first one assumes a random direction of the secondary electrons, corresponding to the idea that slow secondary electrons should be generated with spherical symmetry. Such an approach violates momentum conservation. The second way of calculating the polar and azimuth angles of the secondary electrons takes into account the momentum conservation rules within the classical binary collision model. The aim of this paper is to compare the results of these two different approaches for the determination of the energy distribution of the secondary electrons emitted by solid targets.