Quantum Electrodynamics of Internal Source X-Ray Holographies: Bremsstrahlung, Fluorescence, and Multiple Energy X-Ray Holography

TL;DR

This paper applies quantum electrodynamics to derive and analyze the differential cross sections for three types of internal source x-ray holographies, revealing small virtual particle effects at low energies and quantifying approximation errors.

Contribution

It provides the first QED-based derivation of cross sections for bremsstrahlung, fluorescence, and multiple-energy x-ray holographies, including polarization dependence and virtual particle effects.

Findings

Virtual particles have negligible effects at low energies due to the uncertainty principle.

Using asymptotic wave functions introduces a 5-10% error in near forward scattering.

Derived polarization dependence of the bremsstrahlung x-ray holography cross section.

Abstract

Quantum electrodynamics (qed) is used to derive the differential cross sections measured in the three new experimental internal source ensemble x-ray holographies: bremsstrahlung (BXH), fluorescence (XFH), and multiple-energy (MEXH) x-ray holography. The polarization dependence of the BXH cross section is also obtained. For BXH, we study analytically and numerically the possible effects of the virtual photons and electrons which enter qed calculations in summing over the intermediate states. For the low photon and electron energies used in the current experiments, we show that the virtual intermediate states produce only very small effects. This is because the uncertainty principle limits the distance that the virtual particles can propagate to be much shorter than the separation between the regions of high electron density in the adjacent atoms. We also find that using the asymptotic form of the scattering wave function causes about a 5-10% error for near forward scattering.