Design and calibration of a passive detector for separating neutron, proton and $$\upalpha $$-particles in mixed radiation fields

Abstract

In this study, a new detector is designed based on CR-39, and separately calibrated for protons, neutrons and $$\upalpha $$ -particles under the same etching condition. To that end, an americium–beryllium standard source ( $${}^{241}\hbox {Am--Be}$$ ) and a plexiglass phantom for neutron irradiation, brass collimators and an americium standard source ( $${}^{241}\hbox {Am})$$ for alpha irradiation, as well as a Van de Graaff accelerator for proton irradiation were employed. Sodium hydroxide solution of 6.25 N at $$85^{\circ }\hbox {C}$$ was also used for CR-39 chemical etching. Considering the detection principle of the device, different filters were designed to help distinguish between fast neutron particles, thermal neutrons, albedo neutrons, protons and $$\upalpha $$ -particles in mixed radiation fields. Moreover, both the contribution of each particle and the ability of the designed detector to discriminate energy of charged particles were quantified.