Alpha coincidence spectroscopy studied with GEANT4

Abstract

The high-energy side of peaks in alpha spectra, e.g. 241 Am, as measured with a silicon detector has structure caused mainly by alpha-conversion electron and to some extent alphagamma coincidences. We compare GEANT4 simulation results to 241 Am alpha spectroscopy measurements with a passivated implanted planar silicon detector. A discrepancy between the measurements and simulations suggest that the GEANT4 photon evaporation database for 237 Np (daughter of 241 Am decay) does not accurately describe the conversion electron spectrum and therefore was found to have discrepancies with experimental measurements. We describe how to improve the agreement between GEANT4 and alpha spectroscopy for actinides of interest by including experimental measurements of conversion electron spectroscopy into the photon evaporation database.Index Terms-alpha spectrometry, GEANT4, conversion electrons.