Charge, a Space Radiation Shielding Code

摘要

The report describes CHARGE, a FORTRAN program for the analysis of primary proton and electron passage through plane or spherical shields containing up to 100 regions, and the attendant generation and transmission of electron-induced X-rays (bremsstrahlung) and protoninduced secondary protons and neutrons. Proton and electron analyses use a modification of the range-energy relation applied to as many as one hundred energy groups, while the bremsstrahlung transmission calculation assumes an exponential attenuation corrected by semi-empirical dose buildup factors applied individually to a similar number of gamma ray energies. Availability of several bremsstrahlung source options permit comparison of most commonly used approximations. Energy dependent removal cross sections are used to calculate secondary neutron transmission. The ambient charged particle differential spectra may be specified as varying either as a power of energy or as an exponential of energy over each of several specified energy ranges, in tabulated or functional form. The analysis used is described and results are compared to other calculations and to experiments. (Author)