SUMMARY

The use of a coupled deterministic–Monte Carlo approach for the simulation high-resolution detector response for coupled neutron gamma applications will be examined. Three main research questions will be examined. The first research objective is to determine the tradeoffs between the size of the neutron and photon energy group structure and the angular flux at the detector location. The increase in the number of energy groups also increases the computation size. It is proposed that by separating the discrete and continuum photons a limited number of photon energy groups in the continuum will produce acceptable results. A specialized set of photon production cross sections will be produced using the specific criteria determined by the neutron and photon energy group structures. The second research task will be to determine the relationship between the spatial discretization of the neutron induced photon spectrum and the resulting photon angular flux at the detector location. It is hypothesized that it will be necessary to spatially discetized then neutron reaction rate independent of the neutron transport computational mesh in order to accurately represent the photon production with the material. The third research task is to determine if using the coupled Monte Carlo-deterministic method produces results comparable to MCNP5 and to experiments for high-resolution gamma-ray spectroscopy applications. A simple geometric configuration consisting of a cube of moderated material and a detector is used to complete code-to-code comparisons with MCNP5 to determine the viability of the RADSAT method. Additional experiments will be developed to compare the coupled approach to high-resolution gamma-ray spectroscopy results. It is hypothesized the separation of photons production in continuum and discrete energies will allow the detail to be preserved in the photon transport calculation and used to simulate the detector response.