Transport of an electron beam with the energy of 48-160 fJ through a heterogeneous medium

Using the Monte Carlo method the current and energy flux balance for the accelerated electron beam interacting with the accelerator output foil, air layer and an absorber is calculated. The portions of electron beam reflected into vacuum and absorbed in the foil, air and an absorber at different electron currents and energy fluxes are calculated for the following combinations of initial conditions: 1) the Al and Ti output foil 50 μm thick; 2) the air layer thickness between the output foil and absorber equal to 50, 100, 150 mm; 3) the C and Fe (semi-infinite) absorbers; 4) the initial accelerated electron beam energy in the range of 48-160 fJ (0.3-1.0 MeV). Analysis of the obtained data shows that the presence of the air layer and an absorber behind the output foil considerably affects the number of reflected electrons and energy carried away by them. Starting from the 120 fJ energy the portion of reflected electrons and energy flux is mostly defined by the absorber material with an electron energy increase. For the light absorber (C) within the limits of calculational accuracy (10%) no dependence of the portion of reflected electrons on the air layer thickness within the 50-150 mm range is observed, and for the heavier absorber (Fe) such dependence is observed up to the 120 fJ energy