A Monte Carlo model for low energy D–D neutron generators

Abstract

Deuteron–deuteron (D–D) fusion reactions are foreseen for the next stage fusion reactors. A computational model is developed for simulating the neutron production by accelerating deuterons with energy less then 10 MeV onto solid targets containing deuterium. It requires the specification of the beam and target characteristics (e.g. deuterons energy, deuterium atomic fraction). The model is implemented in the subroutines of the MCNPX and MCNP5 codes, which need so far to be recompiled. The deuterons are transported inside the solid target by a Monte Carlo method. The neutrons are generated with the angle – energy distribution as defined by the laws and nuclear data for the deuteron–deuteron reaction in the ENDF/B-VII.0 library. The sensitivity studies on the input parameters of the D–D model are presented. The D–D source model is finally validated by an experiment, which has been performed by the FNG team at the IRMM with a high energy resolution detector. The results of the simulations indicate that the source model may be useful for the evaluation of the D–D neutron source term and associated uncertainties in experimental facilities.