Neutron and Proton Spectra From Targets Bombarded by 450-MeV Protons

Abstract

The energy spectra of secondary neutrons in the energy region between 100 and 450 MeV emitted by targets bombarded by 450-MeV protons were measured using a proton-recoil spectrometer. Secondary-proton measurements were also made with this spectrometer. The measurements were made on Be, C, Al, Cu, Co, Pb, and Bi targets and at several angles between 0 and 60\ifmmode^\circ\else\textdegree\fi{}. Two general target thicknesses were employed: thin targets in which the primary beam lost little energy and in which further interaction of the secondary particle was small; and thick targets in which the primary beam lost all or a significant fraction of the initial energy and in which the probability of the secondary particles undergoing further interaction was large. The thin-target results are expressed as cross sections and the thick-target results represent a nucleon transport and are expressed as a yield. A number of comparisons of the cross-section results against the Bertini intranuclear-cascade model indicate reasonable agreement for most secondary-proton data and some secondary-neutron data. In the latter case, the position of the observed quasifree scattering peak is at an unexpectedly low energy.