Reaction rate analyses of high-energy neutrons by injection of 100 MeV protons onto lead–bismuth target

Abstract Reaction rate analyses of high-energy neutrons and 100 MeV protons are conducted experimentally by combining the Monte Carlo codes and the nuclear data libraries, in the proton beam transport facility at the Kyoto University Critical Assembly. For the number of neutrons per proton, the ratio of high-energy neutrons for threshold energy under 20 MeV and 100 MeV protons is successfully reconstructed by combining JENDL-4.0 and the INCL model of the PHITS3.0 code with a relative difference about 10% between the experiments and the calculations. The MCNP6.1 code significantly demonstrates with the suitability of combining JENDL/HE-2007 (for high-energy neutrons) and LAHET150 (for protons) for analyzing the 209Bi(n, xn)210-xBi reaction rates of the high-energy neutrons over 20 MeV. In further studies, reaction rate analyses of neutrons over 20 MeV, such as 209Bi(n, 7n)203Bi reactions, still remain to be improved by combining the Monte Carlo code and nuclear data libraries.