Characterization of neutron fields around an intense neutron generator

Abstract

Neutron fields in the vicinity of the University of Ontario Institute of Technology neutron facility have been investigated in a series of simulations and experiments. The neutron fluence at several locations around the neutron generator facility has been simulated using MCNPX 2.7E Monte Carlo particle transport program. The P-385 neutron generator is configured to function with a deuterium-deuterium fusion reaction using accelerated charged deuterons colliding with a metal deuteride target. This fusion reaction is characterized by an anisotropic angular and energy distribution in the centre-of-mass and laboratory frames of reference. Three neutron sources were modelled in the simulation with distributions corresponding to different incident deuteron energies of 130 keV, 110 keV, and 90 keV. An idealized isotropic source was likewise simulated for purposes of comparison and determination of the applicability of such an approximation. Along with the performed simulations and to validate the calculation, a series of experiments have been carried out to determine the dose rate measurement at locations adjacent to the generator. The collected data were used to calculate the neutron intensity of the P-385 neutron generator. The measurements were taken using bubble detectors with different sensitivities. Also, the total dose rates corresponding to applied acceleration potentials were estimated at various locations, utilizing a thin target approximation.