Analysis of neutron yield produced by high energy proton

Vasil'kov et al.'s experiments for neutron yield and neutron capture distribution produced by 400 and 660 MeV protons were analyzed by using ENDF/B-IV data and the BNL codes NMTC and TWOTRAN. The calculated total neutron radiative capture by 238U is 77 and 60% of the measured values for protons of 660 and 400 MeV, respectively. The calculated distribution has the higher peak in the central part of the target system, and steeper gradient both in the r and z directions, compared to experimental. The leakage rate of neutrons from the target assembly is calculated as more than 20%, which is much higher than the 10% estimated from the experiment. The total neutron captures determined using ENDF/B-IV are 3.8 and 3.0% higher than those determined using ENDF/B-III for protons of 660 and 400 MeV, respectively. 12 references