Optimization of a Multiline Neutron Source Based on a 232Th Filter

Abstract

A multiline neutron source can be produced by using a metallic 232Th filter in conjunction with a white neutron source. The multiline spectrum consists of ∼20 relatively strong intensity lines ranging from 10 to 4000 eV. It is shown that the width of each neutron line of the spectrum is strongly dependent on the absorber thickness. This neutron source is useful for accurate cross section measurements with precise neutron energies. The optimum thickness of the 232Th absorber, which was found to yield a sharp multiline spectrum throughout the above energy range, was found to be ∼14 cm.