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

摘要

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