Positron Scattering at Thermal Energies

Abstract

Modied eective range theory in analytical form is used to extrapolate elastic cross-sections down to thermal energies for positron scattering from ve atomic and molecular targets including Ar, H2, N2, C6H6 (benzene) and C6H12 (c-hexane). The derived scattering parameters are then used to estimate the annihilation rates for chosen elements using a simple formula by Gribakin. We show that a combination of two simple models has a potential for accurate parameterization of coecients describing the interaction of thermal positrons with non-polar targets of low polarizability such as Ar and N2.