Application of the new Monte Carlo code AlfaMC to the calibration of alpha-particle sources

Abstract

Abstract. Measurements of -particle sources require corrections to the counting rate due to scattering and self--absorption in the source and the backing material. In this study, we describe a simple procedure to estimate these corrections using the new Monte Carlo code AlfaMC to consider the effects of scattering and self-absorption conjointly, and so to determine the activity of  emitters. The procedure proposed was applied to 235 UO 2 sources deposited on highly polished platinum backings. In general, the dependence of the effi ciency with source thickness was in good agreement with a simple model considering a linear and a hyperbolic behavior for thin and thick sources, respectively, although signifi cant deviations from this model were found for very thin sources. For these very thin sources, the Monte Carlo simulation revealed to be as a required method in the primary calibration of -particle sources. The effi ciency results obtained by simulation with AlfaMC were in agreement with available effi ciency data.

A proposed numerical method for absolute efficiency calibration of α-spectrometers and its application for activity calculation

“…The discrepancy in standard and sample geometry causes a significant inaccuracy in the counting efficiency. Consequently, absolute methods based on mathematical efficiency calibration [13] , [14] , [15] could be considered whenever calibration standards are failed.…”