Description:
<jats:p>Electron pressure profile and transport behaviors in ion Bernstein waves (IBW) heated plasmas were investigated at three frequencies (24, 27, and 30 MHz) in the Hefei Tokamak-7. Both on-axis and off-axis electron heating with global peaked and locally steepened electron pressure profiles were realized, if the ion cyclotron resonant layer was properly selected. Improvement of the IBW-heated plasma confinement was observed except in the 24 MHz case. Reduction of the local electron heat transport was evident from sawtooth heat pulse propagation. High performance plasma volume was extended in the IBW off-axis heating mode, which resulted in improvement of the global plasma confinement. These studies demonstrate that IBW is a potentially powerful tool for active control of plasma profiles and transport.</jats:p>