A DOUBLE-PULSE TOTAL-ABSORPTION FAST NEUTRON SPECTROMETER

摘要

A fast neutron spectrometer utilizing the double-pulse total-absorption technique has been developed for use in the energy range 1-20 Mev. The total absorption spectrometer uses a hydrogenous scintillator, in which a fast neutron may lose all its energy, together with a detector for slow neutrons. Scintillation detection of the disintegration caused by absorption of a slow neutron in an element of high reaction cross section serves to identify those neutrons which lost essentially all their energy in the hydrogenous scintillator.nVarious organic liquid scintillators loaded with natural methyl borate, and a plastic scintillator with a boron-10 or lithium-6 slow neutron scintillation detector nearby were all tested with mono-energetic neutrons obtained from the D(d,n) He3 and T(d,n) He4 reactions. The best experimental results were obtained with a plastic scintillator and a Li6I(Eu) crystal. Representative data for this spectrometer are given below. For comparison purposes, the results of Monte Carlo calculations, made by Leiss1/for a phenylcyclohexane liquid scintillator loaded with methyl borate (B10 enriched), are also included.