Conserving Average Rate of Energy Loss in Transport Calculations for Light Charged Particles

Methods for treating nuclear plus interference elastic scattering of light charged particles in continuous energy or multigroup transport calculations are given. These methods conserve the rate of projectile energy loss and maintain energy balance by ensuring that, on the average, the rate of projectile energy loss equals the rate of target energy gain. It is shown that this approach is equivalent to conserving the P₀ and P₁ moments of the angular distribution of scattered projectiles and targets in the center-of-mass system. We include an approximate method that corrects for the temperature of the medium. To illustrate the application of these methods to a multigroup problem, we give multigroup data for all 25 projectile/target combinations of protons, deuterons, tritons, ³He ions, and alpha particles based on an example 10-group energy structure. The results are in a compact form from which the group-to-group transfer matrices can be easily calculated.