ALPHA-EFFECT OF ALFVEN WAVES AND CURRENT DRIVE IN REVERSED-FIELD PINCHES

Circularly polarized Alfven waves give rise to an alpha-dynamo effect that can be exploited to drive parallel current. In a ''laminar'' magn etic the effect is weak and does not give rise to significant currents for realistic parameters (e.g., in tokamaks). However, in reversed-fi eld pinches (RFPs) in which magnetic field in the plasma core is stoch astic, a significant enhancement of the alpha effect occurs. Estimates of this effect show that it may be a realistic method of current gene ration in the present-day RFP experiments and possibly also in future RFP-based fusion reactors. (C) 1998 American Institute of Physics.