K-shell ionization and characteristic x-ray radiation by high-energy electrons in multifoil targets

TL;DR

This paper analyzes how high-energy electrons induce K-shell ionization and characteristic x-ray radiation in multifoil copper targets, revealing that the process depends on target structure and can significantly enhance x-ray yield.

Contribution

It derives expressions for K-shell ionization and x-ray yield in multifoil targets, showing the dependence on foil number, thickness, and separation, and highlights the potential for increased x-ray production.

Findings

Average K-shell ionization cross section depends on target structure.

CXR yield can be several times higher in multifoil targets.

Comparison with other x-ray emission types shows significant enhancement.

Abstract

Processes of K-shell ionization and accompanying characteristic x-ray radiation (CXR) by high-energy electrons moving through a multifoil copper target are considered. Expressions describing the main characteristics of these processes are derived. It is shown that the average K-shell ionization cross section in the target is not defined just by the target material and the electron energy, but also depends on the number of foils in the target, their thickness and separation between them. The corresponding CXR yield is therefore not unambiguously defined by the aggregated target thickness, but depends on the above parameters as well. It is demonstrated that the average K-shell ionization cross section in a multifoil target can be several times larger than the conventional cross section of this process without the density effect impact. This results in a considerable enhancement of CXR yield from the multifoil target compared to the case of electron incidence upon a single foil of the same aggregated thickness. Comparison of CXR yield in the considered case with the yields of some other types of x-ray emission in multifoil targets is made.