Implementation of atmospheric proton spectrum in GEANT4 simulations for space applications

A major part of cosmic rays consists of the primary protons, and this portion plays a crucial role in the space applications such as shielding of spacecrafts. In this study, the proton flux values measured at the top of the atmosphere through the BESS-TeV spectrometer in 2004 are introduced into the GEANT4 simulations by using a probability grid that generates the corresponding discrete kinetic energies with a certain discrete probability. The introduced scheme is tested over a set of the shielding materials such as aluminum, polypropylene, Kevlar, polyethylene, and water by computing the total absorbed dose, which is the measure of the cumulative energy deposited in the investigated target volumes by protons per unit mass in Gy. It is shown that the present recipe provides the opportunity to use the discrete energy values together with the experimental flux values, thereby demonstrating a beneficial capability in the GEANT4 simulations for diverse space applications.