Self-consistent simulation of the redistribution of co-circulating energetic particles induced by 2/1 tearing mode and 2/1 fishbone-like mode

Abstract The redistribution and loss of co-circulating energetic particles (co-CEPs) in the presence of 2/1 tearing mode (TM) and 2/1 fishbone-like mode (FLM) are self-consistently simulated using the global kinetic-MHD hybrid code M3D-K. It is shown that the distribution function of co-CEPs flattens within the magnetic island region when only the TM is present. The redistribution level can be enhanced by electric field perturbation and smaller orbit widths. When the FLM and TM coexist, the distribution function flattens within the respective regions of each mode, leading to an increasing radial gradient in the intermediate zone between the two modes. When the FLM is dominant, the co-CEPs are primarily redistributed via wave-particle resonance with the FLM. The magnetic island induced by the FLM also exhibits an enhancing effect on the redistribution of resonant co-CEPs. Finally, the initial distribution of the lost co-CEPs is studied. Only the co-CEPs initially located at the plasma edge are found to be lost.