Design of a Collimator for a Fast Neutron Spectrometer by Means of the Monte Carlo Method

摘要

A Monte Carlo code has been used for simulating neutron streaming in a steel collimator of a fast neutron spectrometer. The spectrometer is designed for 14 MeV neutron diagnostics at JET (Joint European Torus). The neutron flux and the energy distribution of the flux are determined at different points outside the collimator. Both the uncollided and the scattered neutrons are studied. The results indicate that the ration of the background to the direct flux at the scattering foil of the spectrometer is less than 0.005. Furthermore, the total flux there in the energy range of (13.9,14) MeV is almost 5 decades higher than the flux at any lower energy. With 10 figures, 1 table and 14 refs. (ERA citation 11:058173)