Magnetohydrodynamic behaviour during core transport barrier experiments with on bernstein wave heating in PBX-M:Ⅱ-n=m-1 and n=m modes

摘要

Two new types of high frequency(HF)MHD mode activity are observed when a core transport barrier is formed during ion Bernstein wave(IBW)heating in PBX-M. these modes, localized in the core transport barrier, seem to be mainly responsible for the soft saturation in the strength of the core transport barrier. The two types of HF mode activity are determined by the presence or absence of a strong 1/1 mode. The n=m modes are observed with the 1/1 mode, while the n=m-1 modes are seen when the 1/1 mode is absent. The m numbers of both of these modes vary between 4 and 13. They all seem to be coupled and rotate as a rigid body.