Effects of High-Power Ion Bernstein Waves on a Tokamak Plasma

Abstract

Effects of high-power ion-Bernstein-wave heating on the PLT tokamak plasmas have been investigated with up to 650 kW of rf power coupled to the plasma. A significant improvement in the deuterium particle confinement (as much as 300%) during high-power ion-Bernstein-wave heating has been observed. Associated with it, a longer injected-impurity-confinement time, reduced drift-wave turbulence activity, frequency shifts of drift-wave turbulence, and development of a large negative edge potential were observed. The ion heating efficiency, $\frac{\Delta T_i\mathrm{}\left(0\right)\mathrm{}{\overline{n}}_e}{P_{\mathrm{rf}}}=6\mathrm{}\times {10}^{13}$ eV ${\mathrm{cm}}^{-3\mathrm{}}$/kW, without high-energy tail ions, is relatively constant up to the maximum rf power.