Corotating drift-bounce resonance of plasmaspheric electron with poloidal ULF waves

The purpose of this paper is to understand how low energy plasmaspheric electrons respond to ULF waves excited by interplanetary shocks impinging on magnetosphere. It is found that both energy and pitch angle dispersed plasmaspheric electrons with energy of a few eV to tens of eV can be generated simultaneously by the interplanetary shock. The subsequent period of successive dispersion signatures is around 40 s and is consistent with the ULF wave period(third harmonic). By tracing back the energy and pitch angle dispersion signatures, the position of the electron injection region is found to be off-equator at around -32° in the southern hemisphere. This can be explained as the result of injected electrons being accelerated by higher harmonic ULF waves(e.g. third harmonic) which carry a larger amplitude electric field off-equator. The dispersion signatures are due to the flux modulations(or accelerations) of " local" plasmaspheric electrons rather than electrons from the ionosphere. With the observed wave-borne large electric field excited by the interplanetary shock impact, the kinetic energy can increase to a maximum of 23 percent in one bouncing cycle for plasmaspheric electrons satisfying the drift-bounce resonance condition by taking account of both the corotating drift and bounce motion of the local plasmaspheric electron.

Simulation of Heating with the Waves of Ion Cyclotron Range of Frequencies in Experimental Advanced Superconducting Tokamak

Simulation on the heating scenarios in experimental advanced superconducting tokamak （EAST） was performed by using a full wave code TORIC. The locations of resonance layers for these heating schemes are predicted and the simulations for different schemes in ICRF experiments in EAST, for example, ion heating （both fundamental and harmonic frequency） or electron heating （by direct fast waves or by mode conversion waves）, on-axis or off-axis heating, and high- field-side （HFS） launching or low-field-side （LFS） launching, etc, were conducted. For the on-axis minority ion heating of 3He in D（3He） plasma, the impacts of both density and temperature on heating were discussed in the EAST parameter ranges.

Investigation of Some MHD Events in the SUNIST Spherical Tokamak

Internal reconnection event （IRE）, which is characterized by a perturbation in plasma current Ip, loop voltage Vloop, Hα radiation and magnetic perturbation dBp, was observed in the SUNIST experiment. It is found that, the fluctuation before IREs is characterized by a structure of m= 2/n = 1, then changes to m = 4/n = 1 during the IREs; and, after IREs, the mode number changes to m = 3/n = 1. An analysis in the evolution of equilibrium parameters during IREs shows that a positive spike appears in the evolution of the plasma＇s elongation and a negative spike in the poloidal beta of plasma. A collapse in the pressure profile, corresponding to the occurrence of IREs, is also found.