Production of sheared flow by means of ICRF heating in tokamak plasmas

Production of poloidal sheared flow during ICRF (ion cyclotron range of frequencies) heating is studied in tokamak plasmas. A now approach of inducing plasma poloidal rotation with rf wave is presented. The mechanism employed here is inducing a poloidal density asymmetry by rf wave and then destabilizing the anomalous Stringer spin up. The production of the poloidal density asymmetry during ICRF heating is analytically and numerically studied on the basis of the Fokker-Planck equation including the conventional collision and quasilinear rf diffusion operators. A model of jointing the rf power with the plasma rotation is presented to study the destabilization of the plasma rotation triggered by rf wave. A criterion upon destabilization of the plasma rotation in the presence of rf wave is given, which depends on the ratio of the electron slowing-down time to the ion collision time. The criterion is specified in the high rf power limit in the case of ICRF minority fundamental heating. (author)