Neutron multiplicities and continuum neutron spectra from 200-MeV proton bombardment of carbon, aluminum, iron, lead, and uranium

Double differential continuum neutron spectra from 200-MeV proton bombardment of carbon, aluminum, iron, lead, and uranium were measured at angles of 30, 45, 90, and 135 deg using pulse-shape discrimination (PSD) techniques. Data were obtained using different sizes of BC 501 detectors, 2 {times} 2, 5 {times} 5, and 5 {times} 10 in. Thin and thick data were compared with intranuclear cascade calculations and with the high-energy transport code (HETC). The total neutron yields were calculated from these neutron spectra. Comparison of experimental double differential neutron spectra results with the Monte Carlo calculation is good in general. However, noticeable differences are present at the high neutron energy region for some angles. The uncertainty in the experimental results is a combination of the statistical uncertainty in the neutron pulse height distribution measurement and errors introduced by the unfolding process, which resulted in spurious oscillations and some unphysical negative values during iteration that are in the acceptable range. The neutron multiplicities per incident proton are given in Table I. The double differential data were integrated by energy to obtain the angular distributions for the various angular data sets and for the angle integrated to give the total cross sections or neutron yieldsmore » per proton for the various targets.« less