PROJECT TITLE :

Validation of Cross Sections for Monte Carlo Simulation of the Photoelectric Effect

ABSTRACT:

Several total and partial photoionization cross section calculations, based mostly on both theoretical and empirical approaches, are quantitatively evaluated with statistical analyses employing a massive collection of experimental information retrieved from the literature to spot the state of the art for modeling the photoelectric impact in Monte Carlo particle transport. A number of the examined cross section models are obtainable generally purpose Monte Carlo systems, while others are implemented and subjected to validation tests for the primary time to estimate whether or not they might improve the accuracy of particle transport codes. The validation process identifies Scofield’s 1973 non-relativistic calculations, tabulated within the Evaluated Photon Data Library (EPDL), as the one best reproducing experimental measurements of total cross sections. Specialized total cross section models, some of which derive from a lot of recent calculations, don't give significant enhancements. Scofield’s non-relativistic calculations are not surpassed relating to the compatibility with experiment of K and L shell photoionization cross sections either, although during a few take a look at cases Ebel’s parameterization produces a lot of accurate results close to absorption edges. Modifications to Biggs and Lighthill’s parameterization implemented in Geant4 significantly cut back the accuracy of total cross sections at low energies with respect to its original formulation. The scarcity of suitable experimental data hinders a similar extensive analysis for the simulation of the photoelectron angular distribution, which is restricted to a qualitative appraisal.