An algorithm for electron depth-dose distributions in multilayer slab absorbers

An algorithm to evaluate depth-dose distributions produced by plane-parallel electron beams normally incident on two- or three-layer slab absorbers has been developed. It is based on a simple model of electron penetration across the interface, and makes use of empirical equations previously formulated as well as ones newly developed. Distributions obtained by the algorithm have been compared with available experimental and Monte Carlo results for electrons of incident energies from 0.1 to 10 MeV, showing good agreement in most cases. The algorithm is considered to be valid for incident energies from 0.1 to 20 MeV and for absorbers consisting of slabs of atomic numbers from about 5.6 (polystyrene) to 82. (author)