Fine Powder Proportional Counters for Neutron Detection

Abstract

A novel neutron detection approach is presented, consisting of a neutron sensitive aerosol obtained by dispersing B4C fine powder in a gaseous proportional counter operating in continuous flow, which proved to effectively detect thermal neutrons. This technique shows potential to be an affordable alternative to 3He neutron detectors, providing an additional mechanism to overcome the 3He shortage crisis that compromises the deployment and maintenance of neutron detectors in research facilities and security applications. The effect of the B4C nanoparticles in the charge gain and energy resolution of a proportional counter filled with Ar-CH4 (90%-10%), by irradiation with x-rays from a 55Fe source shown an average gain loss of 36% and increase in energy resolution (FWHM) by 15% (absolute value). Results obtained by thermal neutron irradiation are also presented, showing neutron captures in which the simultaneous energy deposition of both reaction products from the 10B neutron capture reaction was achieved.