1 THW/P4-03 Simulation Study of Toroidal Flow Generation by the ICRF Minority Heating

Abstract. The toroidal flow generation by the ICRF minority heating is investigated in the Alcator C-mod like plasma applying GNET code, in which the drift kinetic equation is solved in 5D phase-space. An asymmetry of distribution function in the parallel direction is found and two kinds of toroidal flow are observed. One is the sheared flow near the RF power absorption region depending on the sign of kk. The other is the toroidal flow, which is larger than the previous one, independent of the sign of kk. Additionally the toroidal flow reversal from co to counter direction is obtained when we change the toroidal current to the opposite direction. These facts indicate that there exists two kinds of the driving mechanism of toroidal flow. Two models to explain the obtained toroidal flow are studied. We find that the toroidal motions of energetic tail ions caused by the finite banana effect in the finite magnetic shear and, also, by the poloidal magnetic drift plays important role in the generation of the toroidal flow. 1