Neutron activation and prompt gamma intensity in Ar/CO\(_{2}\)-filled neutron detectors at the European Spallation Source

Abstract

Monte Carlo simulations using MCNP6.1 were performed to study the effect of neutron activation in Ar/CO\(_{2}\) neutron detector counting gas. A general MCNP model was built and validated with simple analytical calculations. Simulations and calculations agree that only the \(^{40}\)Ar activation can have a considerable effect. It was shown that neither the prompt gamma intensity from the \(^{40}\)Ar neutron capture nor the produced \(^{41}\)Ar activity have an impact in terms of gamma dose rate around the detector and background level.