Comparisons of Monte Carlo and ICRU electron energy vs. range equations

Depth-dose distributions in water and in polystyrene absorbers with a variety of incident electron energies extending from 0.3 to 25 MeV have been calculated with the one-dimensional ITS TIGER Monte Carlo code. Practical electron ranges have been obtained from these distribution curves using a new mathematical procedure. Polynomial equations have been derived which correlate the electron energy vs. range values within 1% from the lowest to the highest energies. Comparisons of the electron energies obtained with our theoretical equation for water with the values IF obtained with the empirical equation given in ICRU Report 35 show agreement within about 1% for electron energies between 5 and 25 MeV. This close agreement provides assurance that the ranges obtained by Monte Carlo calculations are reliable for these energies. The energy differences between our theoretical equation for water and the ICRU empirical equation tend to increase for lower energies. The maximum disagreement is about 8% for electron energies below 1 MeV. (C) 2004 Elsevier Ltd. All rights reserved.