PLASMA BIASING BY RADIAL ELECTRIC-FIELDS INDUCED IN FRONT OF LOWER-HYBRID GRILLS VIA POLOIDAL PONDEROMOTIVE FORCES

This article treats the stationary radial electric field that the lowe r hybrid wave induces in front of the grill of the exciting antenna st ructure. The source of the induced electric field is the poloidal pond eromotive force of lower hybrid waves. It is shown that electric field s of the order of tens of volts per cm are possible in tokamak dischar ges. The required poloidal ponderomotive force would be possible if th e mutual phasing of the horizontal waveguide rows of the grill were of a suitable value. It has been found that the induced radial electric field and the associated poloidal and toroidal plasma rotation will un dergo sign changes if the poloidal phasing of the grill is altered app ropriately. (C) 1997 American Institute of Physics.