Time of Flight System for MeV Neutron

The fast neutron facility with a prototype detecting system at the Korea Institute of Geoscience and Mineral Resources (KIGAM) was constructed in 2007. The detecting system was upgraded by changing the detecting sensor and its size and by changing the distance from the detector to the neutron target. The (3)H(p,n)(3)He reaction with a Ti-(3)H target was used to estimate the time resolution of the upgraded system. The time resolution of the system was observed to be 36 keV (1.79 ns) at 2.077 MeV by analyzing the absorption width of the neutron energy spectrum for (12)C. The main factor for the time resolution of the system is thought to be a variation in the repetition time of the bunching beam. The width of the neutron energy spectrum was 150 keV, which corresponded to the proton energy loss caused by a Ti thickness of 2 mg/cm(2) (4.44 mu m) oil the Ti-(3)H target. The neutron total cross sections for (12)C and (28)Si were measured by using the upgraded detecting system and the results are compared with the data for Evaluated Nuclear Data File-VI (ENDF-VI).This research was supported by the Korean Ministry of Science and Technology as one of its long-term nuclear R&D programs