Discrete Alfvén eigenmodes under the condition <_ufe:lines-br xmlns:_ufe="http://www.arbortext.com/namespace/Styler/UserFormattingElements" xml:base="-7mm"> </_ufe:lines-br>of bootstrap current in EAST
Abstract
Basing on experimental advanced superconducting Tokamak (EAST), we have researched relation between bootstrap current and <italic>α</italic>-induced toroidal Alfvén eigenmode (<italic>α</italic>TAE, <italic>α</italic> is a measure of plasma pressure gradient), which is investigated, in this paper, for the EAST tokamak operation condition with the bootstrap current. Our results show that the <italic>α</italic>TAE may exist in a relatively broad region of minor radius, where a large bootstrap current density is observed. In the presence of energetic particles, produced by the NBI experiments, our MHD-gyrokinetic hybrid simulations demonstrate that this quasi-marginally stable <italic>α</italic>TAE (within MHD description) can be readily destabilized by the kinetic compression upon the wave-particle resonances.