The Amplitude of a Process with Direct Ionization of the Atom

TL;DR

This paper develops an analytic method to understand how Coulomb interactions influence the spectrum and angular distribution of electrons emitted during above-threshold ionization, considering multiple scattering events.

Contribution

It introduces an analytic approach accounting for multiple Coulomb scatterings of the photoelectron, providing explicit amplitude calculations for direct ionization processes.

Findings

Analytic expressions for ionization amplitudes including Coulomb scattering.

Insights into the role of Coulomb interaction in electron spectra.

Framework for predicting angular distributions of emitted electrons.

Abstract

We consider an analytic approach to the elucidation of the role played by Coulomb interaction in the formation of the spectrum and angular distributions of the electrons produced by above threshold ionization of the atoms. Our approach is based on allowance for the multiple scattering of a photoelectron by the Coulomb potential of the residual ion, with pickup of a field photon in each scattering act. The amplitude of a process with direct ionization of the atom and subsequent scattering of the photoelectron in the continuum by the Coulomb potential of the residual ion are found.