Electronic structure effects in the electron bremsstrahlung from heavy ions

TL;DR

This paper presents a relativistic method to analyze how the electronic structure of heavy ions affects the bremsstrahlung radiation emitted by electrons scattered off them, with results relevant to experimental observations.

Contribution

It introduces a comprehensive relativistic approach that incorporates the electronic structure of ions into bremsstrahlung calculations, improving accuracy over previous models.

Findings

Electronic structure modifies bremsstrahlung cross-section by about 14%.

The approach successfully explains experimental data for uranium ions.

Results highlight the importance of target electronic structure in high-energy electron scattering.

Abstract

A fully relativistic approach is presented for the calculation of the bremsstrahlung emitted by an electron scattered off an ionic target. The ionic target is described as a combination of an effective Coulomb potential and a finite-range potential induced by the electronic cloud of the ion. The approach allows us to investigate the influence of the electronic structure of the target on the properties of the emitted radiation. We calculate the double differential cross-section and Stokes parameters of the bremsstrahlung of an electron scattered off uranium ions in different charge states, ranging from bare to neutral uranium. Results on the high-energy endpoint of the electron bremsstrahlung from Li-like uranium ions ${\rm U}^{89+}$ are compared to the recent experimental data. For this process, it is found that taking into account the electronic structure of the target results in modification of the cross-section on the level of 14%, which can, in principle, be seen in present-day experiments.