Theoretical Analysis Of Frequency Jump In E-fishbone Experiments And Particle Orbital Simulation

The resonance between inter kink mode and energetic particle can excite fishbone instability.This instability will lead to the ejectment of the energetic particle and it also will degrade the confinement of the plasma.In this paper the theoretical analysis of the periodic frequency jump of the fishbone mode in HL-2A and Tore Supra tokamak experiments is given.Based on the resonance condition of fishbone instability,it is identified that the barely passing electrons lead to the periodic frequency jump.Firstly ignoring the contribution of the processing frequency of the electron,we can solve the dispersion equation of e-fishbone mode.It finds E-fishbone frequency increases with the hot electron energy between 7 and 13 kHz which is consistent with the experimental observation in the vicinity of the q=1 surface.The growth rate of the mode(m=2,n=2)is greater than the one of the mode(m=1,n=1).This paper also simulates the burst behavior of the barely passing electrons by the predator-prey principle.Finally my second work is described.Electric potential as a function of associated with magnetic flux2(37)=A?(10)B? is introduced.With the electric potential we use the Boris algorithm to simulate the real alpha particle ’ s full orbit in International Thermonuclear Experimental Reactor(ITER).The simulation results show that the potential coefficient A and B have different influence on the ion full orbit and the ion’s orbit loss.The banana orbit and circulating orbit of the ion full orbit can mutually converting by changing the potential coefficient A and B.This paper mainly put forward idea that the fishbone frequency jump between high frequency(2/2 model)and low frequency(1/1 model)phenomenon found in HL-2A device be caused by the bounce frequency of the barely passing electrons.Moreover the simulation results basde on this theoretical perspective fits well with experiment.Therefore the results will have an important effect on the latter study about fishbone instability.