Fast Ion Anomalous Diffusion And Its Effect On Heat Transport During Neutral Beam Injection In EAST Device

Neutral beam injection(NBI)is one of the most important heating method and it's also the primary tools for heating,current drive(CD)and q-profile control in future fusion reactors such as ITER and other Nuclear Fusion devices.It is important to investigate the behavior of energetic particle during the neutral beam injection(NBI),thus the effects of energetic particle on heating transport should be investigated.In this thesis anomalous transport of fast ions is assumed in the simulations,and then Alfven continuum spectrum and the mode structures of TAEs are calculated for comparison between neo-classical fast-ion transport and anomalous fast-ion transport.The fast-ion transport is anomalous when the minimum safety factor(qmin)is about 2,while it is neo-classical when qmin is around 1.Moreover,high qmin discharge with anomalous fast-ion transport has more AE activity than that of lower qmin discharge.The fast ion diffusion behavior and its influence on background plasma heat transport are also investigated during NBI.NBI heating efficiency,plasma stored energy and the total heating power are reduced when the fast ion transport is anomalous.The fast ion diffusion coefficient,electron temperature have influenced on the effective heat transport coefficient,and they have the opposite effect on heat transport,which is confirmed in the simulation.This investigation is helpful to understand the mechanism of anomalous transport during neutral beam injection(NBI)in EAST and to provide guidance for future experiments.