Time dependent neutron emission rate analysis for neutral-beam-heated deuterium plasmas in a helical system and tokamaks

A neutron rate analysis code called the FBURN, based on the classical energetic ion confinement assumption with radial diffusion, is developed for the time-dependent analysis of the total neutron emission rate (Sn) in neutral beam (NB) heated deuterium plasmas.The time trend of Sn evaluated by the FBURN shows good agreement with the Sn measured by the neutron flux monitor on the deuterium operation of the Large Helical Device (LHD).The dependence of Sn on line-averaged electron density (ne_avg) has a peak is due to the diffusion of tritons.Time trend analysis of Sn in the Korea Superconducting Tokamak Advanced Research (KSTAR) and the Experimental Advanced Superconducting Tokamak (EAST) plasmas with a short pulse NB injection is performed.The time trend of Sn is successfully reproduced by the FBURN.