Ranges of electrons and positrons in solids, chemical compounds and alloys

Abstract

A detailed theory of multiple scattering of electrons and positrons in solids, chemical compounds and alloys is described. A new method for calculating the diffusion energyTr and the corresponding mean square scattering angle θ for the random motion of the particles is described. Multiple scattering and radiation corrections are applied to continuous slowing down approximate ranges, reported by Berger and Seltzer. The solids investigated were Al, Sc, Cu, Y, Ag, La, Nd, Eu, Ho, Yb and Pb. A number of chemical compounds and alloys such as water, benzene, toluene, plaskon, lumarith, brass and heavy water was also investigated. The data also include a number of single crystals such as NaCl, KC1, KBr and KI. Finally some inert gases including He, N, Ne, Ar, Xe and Kn were checked. Theoretical ranges were calculated in the 1.88 MeV, 0.960 MeV and 0.320 MeV regions for all the materials. The ratio of positron range to electron range for a given energy was calculated. The theoretical ratio was compared to the experimental ratio. The present calculations are in good agreement with the previous experimental data for Al, Cu, Y, Sn and Pb in the 2 MeV region. However, there are significant differences at low energy and for other materials.