AN ALGORITHM FOR MONTE-CARLO SIMULATION OF COUPLED ELECTRON-PHOTON TRANSPORT

An algorithm for Monte Carlo simulation of coupled electron-photon tra nsport is described, Electron and positron tracks are generated by mea ns of PENELOPE, a mixed procedure developed by Baro et al. [Nucl. Inst r, and Meth. B 100 (1995) 31]. The simulation of photon transport foll ows 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 t hrough analytical differential cross sections, derived from simple phy sical models and renormalized to reproduce accurate attenuation coeffi cients available from the literature, The combined algorithm has been implemented in a FORTRAN 77 computer code that generates electron-phot on showers in arbitrary materials for the energy range from similar to 1 GeV down to 1 keV or the binding energy of the L-shell of the heavi est element in the medium, whichever is the largest. The code is capab le of following secondary particles that are generated within this ene rgy range. The reliability of the algorithm and computer code is demon strated by comparing simulation results with experimental data and wit h results from other Monte Carlo codes. (C) 1997 Published by Elsevier Science B.V.