The (n, p), (n, d) and (n, α) reactions induced by 14.6 MeV neutrons in CsI(Tl) scintillation crystals

Abstract

The (n, p), (n, d) and (n, α) reactions induced by 14.6 MeV neutrons in CsI(Tl) scintillation crystals have been observed. Pulse shape discrimination has been used to distinguish the various particles, permitting an energy spectrum for each to be obtained. The proton and alpha particle spectra have been analysed from the point of view of the statistical theory of nuclear reactions, but there are left over substantial components which must be attributed to direct interactions. The direct component for protons is estimated to be at least 45 %, and for alpha particles to be at least 38 %. Absolute cross sections have been obtained by the method of “tagging” the neutron beam by its associated particles; the averages for Cs and I are found to be σ(n, p) = 8±1 mb, σ(n, d) = 1.2±0.2 mb and σ(n, α) = 1.8±0.2 mb.