Generation of a plasma neutron source for Monte Carlo neutron transport calculations in the tokamak JET

Highlights: • Novel methodology for detailed plasma neutron source studies in the tokamak JET. • TRANSP/NUBEAM used for plasma transport and fast ion distribution calculations. • DRESS used for neutron spectra and neutron emission angle computations. • NBI plasma heating found to significantly affect the neutron birth rate profile. - Abstract: The connection between plasma physics and neutronics is crucial for the understanding of the operation and performance of modern and future tokamak devices. Neutrons are one of the primary carriers of information on the plasma state and represent the basis for various plasma diagnostic systems as well as measurements of fusion power, tritium breeding studies, evaluations of tokamak structural embrittlement and the heating of water inside the fusion device's walls. It is therefore important that the birth of neutrons in a plasma and their transport from inside the tokamak vessel to the surrounding structures is well characterized. In this paper a methodology for the modelling of the neutron emission on the tokamak JET is presented. The TRANSP code is used to simulate the total neutron production as well as 2D neutron emission profiles for a JET plasma discharge. The spectra of the fusion neutrons are computed using the DRESS code. The computational results are analysed in an effort to create a plasma neutron source generator, which is to be used for Monte Carlo neutron transport computations.