Optimization of Experimental System Design for Benchmarking of Large Angle Scattering Reaction Cross Section at 14 MeV Using Two Shadow Bars

Abstract

At 14 MeV, it is known that the absolute value of large angle scattering cross section is small. The contribution is thus thought to be neglected in the neutronics design of fusion reactor. However, in case that a neutron source can be regarded as a beam like a neutron streaming, large angle scattering cross sections might affect the nuclear design result largely. In fact, in fusion neutronics benchmark experiments using a neutron beam so far, there was a difference observed between experiment and simulation. Also it is known that there are differences in large angle scattering cross sections among nuclear data libraries. Then we have been carrying out preliminary benchmark experiments for verification of large angle scattering reaction cross sections of iron for a few years. The purpose of the present study is to optimize the experimental system design to realize an accurate benchmarking of large angle scattering reaction cross sections. Finally, we reached the optimized experimental system and developed the experimental procedure which was supposed to perform more accurate benchmark experiments for large angle scattering reaction cross sections.