Spectrum of a neutron source based on a solid tritium target

摘要

The spectra of neutrons produced by bombarding a tritium-titanium-molybdenum target with 4-9-MeV protons were measured by the time-of-flight technique at various angles. Apart from the neutrons from the T(p, n) reaction, low-energy neutrons were detected, which equaled from 4 to 3000% of the monoenergetic neutrons. Theoretical analysis showed that emission of these low-energy neutrons could be caused by neutron scattering from the structural materials of the target assembly or by the (p, n) reaction on titanium and molybdenum. In addition, when traveling towards the detector, neutrons from the T(p, n) reaction were inelastically scattered by the collimator walls in the detector shielding. Computations by the Monte Carlo and Hauser-Feschbach codes quantitatively reproduced the measured spectra. The approach tested can be used for other neutron-production reactions and for other target assemblies to estimate the contribution of nonmonoenergetic neutrons.