Bremsstrahlung on noble gases at low energies

TL;DR

This paper provides a detailed analysis of bremsstrahlung spectra during nonrelativistic electron scattering on noble gases, revealing inaccuracies in common approximation formulas and establishing a rigorous relationship with electron transport cross sections.

Contribution

It offers the first rigorous proof linking bremsstrahlung spectra to electron transport cross sections without assumptions on scattering phase dependence.

Findings

Approximate formulas significantly differ from exact results.

Exact predictions align well with experimental data below luminescence threshold.

A rigorous proof relates bremsstrahlung spectrum to electron scattering cross sections.

Abstract

A detailed analysis of the bremsstrahlung spectrum at nonrelativistic electron scattering on argon and xenon is carried out. It is shown that the approximate formulas widely used for the description of bremsstrahlung spectra lead to predictions that significantly differ from the exact results. In the limit when the photon frequency tends to zero, a rigorous proof of the relationship between the spectrum of the bremsstrahlung with a transport cross section of electron scattering on an atom is given. This proof does not require any assumptions about the dependence of the scattering phases on energy. For electron energies lower than the luminescence threshold, it is shown that the predictions for a number of radiated photons obtained by the exact formula are in good agreement with the available experimental data.