Coherent Compton scattering from hydrogen and helium atoms

TL;DR

This paper presents a relativistic AA-approximation method to accurately describe coherent Compton scattering from hydrogen and helium atoms, accounting for electron boundness effects and matching known high-energy limits.

Contribution

It introduces a new relativistic approach within the S-matrix formalism for coherent Compton scattering that improves upon previous models by incorporating bound electron effects.

Findings

Formulas accurately reproduce cross sections at large photon energies

Method correctly transitions to Thomson and Klein-Nishina formulas in appropriate limits

Provides a consistent framework for keV photon scattering from light atoms

Abstract

We develop an approach to describing coherent Compton scattering of photons in the keV energy range from hydrogen and helium atoms based on a relativistic version of the AA-approximation within the standard perturbative S-matrix formalism. The resulting formulas for the cross section take into account the effects of the electron boundness and correctly reproduce the behavior of the cross section at large photon energies, where it goes to Thomson formula, which coincides with the Klein-Nishina-Tamm formula for the cross section in the non-relativistic limit.