ELECTRON DEPTH-DOSE DISTRIBUTIONS IN WATER, IRON AND LEAD - THE GEPTS SYSTEM

Electron depth dose distributions are computed by means of a Monte Carlo simulation. To achieve this purpose, a new transport system, GEPTS, is used. The latter is designed for electrons, positrons and photons. GEPTS incorporates various refinements (new multiple scattering and energy loss distributions, binding effects in Compton scattering, K, L and M-shell photoionisation, etc.) as well as improvements in the cross section information. Some of the previous GEPTS results are compared with measurements and with those from other codes (ETRAN, ITS). The electron depth dose distributions are calculated considering a semi-infinite target (water, iron or lead) and two possible source configurations: normally incident broad parallel beam and isotropic point source located at the boundary of the target. To provide a comparison, the EGS4 system also is used to produce the expected electron depth dose distributions.