Boron-Loaded Neutron Detector with Very Low γ-Ray Sensitivity

Abstract

A boron-loaded liquid scintillator is described which gives a much greater difference in the pulse shapes for γ rays and for slow neutrons than any of the liquids currently used. A detailed study of the pulse shapes indicates that the γ-ray sensitivity of a neutron detector filled with this liquid can be reduced by a factor of 500 with only a 5% decrease in the neutron sensitivity by application of pulse-shape discrimination. A survey of the pulse-shape characteristics of a number of scintillators currently used, together with the results for the new liquid, is presented, and the performance of the new detector with a simple system of pulse-shape discrimination is described.