Development of a neutron source for imaging at the electron linac facility in Kyoto University Research Reactor Institute

The Kyoto University electron linac, KURRI-LINAC, has been used for executing a project to develop methodology for the integrity evaluation of nuclear fuels, named the N-DeMAIN (Development of Non-Destructive Methods Adapted for Integrity test of Next generation nuclear fuels) project in Japan. As a non-destructive method, the neutron resonance transmission analysis was adopted for the identification and the quantification of nuclide in the fuels. Furthermore, determination of temperature distribution in the fuels based on Doppler broadening was also planned as well as traditional transmission imaging. A target-moderator-reflector system (TMRS) and a beam collimator system has been redesigned to obtain the highest intensity with the use of simulation calculation. The neutron beam line is placed at an angle of 135° with respect to the electron beam line. Optimal arrangement of the target and the moderator was investigated. After then, collimator design was performed, and a collimator system to shape the neutron and γ ray beams was designed. Test experiments were performed by using this system. Here, we explain the results of design study of the TMRS and the collimator, and the test experiments.