Implementation of linearly-polarized photon scattering into the EGS4 code

A modification to the general-purpose Monte Carlo electron-photon transport code EGS4 backslash lbrackvertical stroke Nelson, Hirayama and Rogers, SLAC-265 backslash rbrackvertical stroke was made in order to include linear polarization in the simulation of photon scattering. Both the Compton and Rayleigh scattering routines were modified to properly account for the electric-field vector of the photon. This vector is calculated at each photon scatter, and is passed along with the photons in the radiation transport, thereby allowing for a precise simulation of polarized multiple scattering. A simulation of the absorbed-dose distribution in a soft tissue equivalent phantom for a linearly polarized incident photon beam, scattering many times, was successfully performed. (orig.)