Scattering and self-absorption corrections in the measurement of $α$-particle emitters in 2$π$ geometry

Abstract

Accurate measurements of α-particle emitting sources with 2π detectors require corrections due to scattering and self-absorption of α-particles from the source and from the backing material. We applied the Monte Carlo computer code SRIM, developed to simulate the transport of ions in matter, to the study of these corrections in the most general case, i.e. to the measurement of α-particle emitters with low specific activity, where the self-absorption effect in the source is considerable. The values of the ratio C2π/N0 (counting rate divided by disintegration rate) were calculated for sources of uranium dioxide containing a mixture of 235U and 234U mounted on a platinum backing, with a wide range of source thicknesses from 0.0 to 1.1 mg/cm2. The calculated ratios were in agreement with the available experimental data. The work shows that Monte Carlo simulation of the transport of ions by means of the code SRIM can be a very useful tool to evaluate the corrections needed in the measurement of α-particle sources with 2π detectors.

Alfonso Fernandez Timon

Associate Professor

Alfonso Fernández Timón is Associate Professor and one of the senior researchers of the Optimization Algorithms Research Group GRAFO at the Universidad Rey Juan Carlos. Previously he was a fellow of the Metrological Stations Network and of the Radiological Surveillance Plan of the CSN at the University of Extremadura. His research interests range from the application of metaheuristics to solve combinatorial optimization problems to nuclear radiation metrology.