Warm plasma dispersion relation of the fast Alfven wave for asymmetrical heating current drive

Experimental observation of current drive by asymmetrical heating of ions in the Texas Tech Tokamak suggests that penetration of the fast Alfven wave near the fundamental ion-cyclotron resonance is restricted. A numerical study of the warm plasma dispersion relation near the ion-cyclotron resonance does indeed show this effect. The data reveal that, as the wave approaches the resonant layer from the high or low field side of the torus, it first passes through a region where asymmetrical heating takes place and the wave energy is absorbed by ions moving with high velocity parallel to the magnetic field