The computation of pion depth-dose curves in water and comparison with experiment.

Abstract

A Monte Carlo program has been written for calculating absorbed dose as a function of position in a water target irradiated by beams of pions (π+ and π-). The incident pions can have an arbitrary energy spectrum, at present limited to 125 MeV, this energy including most beams that have been used in radiobiological experiments. The presence of muons and electrons, which contaminate pion beams in practice, is also included. The incident particles may enter the target at any point and with any direction of travel. Calculations can thus be made for nonparallel, nonuniform beams. The size of cylindrical volumes in the target over which the absorbed energy is averaged can be varied to simulate the use of detectors of various dimensions. The calculations include pion-nucleus interactions, multiple coulomb scattering, pion and muon decay at rest, as well as the transport and further interactions of secondary protons and neutrons. Good agreement is obtained between calculated and measured depth-dose curves with π+...