  In HT-7 tokamak, the m= 2/1 tearing mode can be effectively suppressed by the
ion bernstein wave (IBW) when the location of power deposition is near the q=2
rational surface. Off-axis electron heating and greatly increase of electron
density was observed, in the meantime, the particle confinement appears to be
improved with the increased of the central line averaged electron density and
the drop of Da emission. Induced large ne gradients and pressures were
spatially correlated with the IBW deposition profile by theoretical calculation
>. It is suggested that off-axis IBW heating modifies the electron pressure
profile, and so the current density profile could be redistributed resulting in
the suppression of the magnetohydrodynamics (MHD) instability. It provides an
integrated way for making combined effects on both the stabilization of tearing
modes and controlling of pressure profile.
