Application of ion transport simulation to the backscattering in α-particle sources

Abstract

The standardization of α-particle emitting sources with 2π detectors requires corrections for backscattering from the backing material. The Monte Carlo computer code SRIM, developed to simulate the transport of ions in matter, was applied to the study of the backscattering of α-particles in different materials. Simulations of 5.3 MeV α-particles from 210Po were performed for various backing materials with atomic numbers ranging from 13 to 79. In addition, some experiments using a 2π detector and a well-defined low solid angle chamber with a silicon detector were also performed. The experimental backscattering coefficients for 241Am α-particle sources in Pt and Ag supports and for 239Pu αs in stainless steel and quartz backing materials were determined. There was reasonable agreement between calculations and experimental results (carried out by us and by other laboratories). This work shows that Monte Carlo simulation of the transport of ions can be a very useful tool to evaluate the backscattering corrections in the standardization of α-particle sources.