Refined Monte Carlo modelling of fusion neutron emission in magnetically confined plasmas

A new refined modelling procedure for calculating a series of weighted samples for birth distributions of fusion products from arbitrary ion velocity distributions is presented. The weighted samples can be used directly as input to other codes. This is particularly useful if the fusion products are neutrons and their migration from the plasma to a detector or a certain point in space is simulated by using the Monte Carlo neutron-photon transport code MCNP. As an application of the new sampling procedure, numerical results for a test plasma using data of a neutral-beam-heated discharge of the stellarator W7-AS are presented.