Bremsstrahlung contribution to the X-ray spectrum in coupled photon-electron transport

摘要

Secondary electrons produced by Compton scattering and photoelectric effect contribute to the photon field through conversion mechanisms like bremsstrahlung and inner-shell impact ionization (ISII). Because electrons interact continuously, the solution of the coupled transport problem is complex and time consuming. For this reason, photon transport codes frequently neglect the effects due to secondary electrons. Both of these contributions have been computed by means of the ad hoc code KERNEL that uses the Monte Carlo code PENELOPE specific for coupled transport. The correction on the intensity of the characteristic lines due to ISII was treated in a recent paper of our group. This paper adds the continuous contribution to the radiation field due to bremsstrahlung by secondary electrons. The bremsstrahlung emission is studied in terms of angle, space, and energy. The continuous contribution is stored in a data library for selected photon source energies in the interval 1-150 keV and for all the elements Z=1-92. For intermediate source energies, the single element contribution is obtained by interpolating the data library. An example is presented on how to use the data library to include bremsstrahlung in the simulation of a synchrotron experiment. Copyright (C) 2015 John Wiley & Sons, Ltd.