An algorithm for Monte Carlo simulation of coupled electron-photon transport

Abstract An algorithm for Monte Carlo simulation of coupled electron-photon transport is described. Electron and positron tracks are generated by means of PENELOPE, a mixed procedure developed by Baro et al. [Nucl. Instr. and Meth. B 100 (1995) 31]. The simulation of photon transport follows the conventional, detailed method. Photons are assumed to interact via coherent and incoherent scattering, photoelectric absorption and electron-positron pair production. Photon interactions are simulated through analytical differential cross sections, derived from simple physical models and renormalized to reproduce accurate attenuation coefficients available from the literature. The combined algorithm has been implemented in a FORTRAN 77 computer code that generates electron-photon showers in arbitrary materials for the energy range from ∼1 GeV down to 1 keV or the binding energy of the L-shell of the heaviest element in the medium, whichever is the largest. The code is capable of following secondary particles that are generated within this energy range. The reliability of the algorithm and computer code is demonstrated by comparing simulation results with experimental data and with results from other Monte Carlo codes.