Low-energy-threshold detector for measuring proton spectra at several tens of MeV using Bragg curve spectroscopy

Abstract

We have developed a low-energy-threshold detector comprising a Bragg curve counter (BCC), two silicon-surface barrier detectors, and a bismuth germanate scintillator to obtain experimental double-differential cross section (DDX) data on (p,p′x) reactions for incident energies of several tens of MeV. The BCC can identify particles by itself and can do so for protons down to 1 MeV. The developed detector is used to measure the DDXs of (p,p′x) reactions for incident proton energies of 40 and 70 MeV at 15–150°. The minimum energy in the DDX data is 1.3 MeV, which gives spectra of emitted particles in the whole energy range. The resultant DDXs are compared with results calculated using intranuclear cascade plus evaporation models. Below 10 MeV, the calculation results agree reasonably with measured data for the natC(p,p′x), 27Al (p,p′x), and natCu(p,p′x) reactions, but they disagree regarding energy and angular dependence for the 197Au(p,p′x) reaction.