Effect of externally imposed and self-generated flows on turbulence and magnetohydrodynamic activity in tokamak plasmas

The effects of externally imposed and self-generated poloidal flows on turb ulence and magnetohydrodynamic (MHD) activity are examined in the context o f the possible Electric Tokamak (ET) [Phys. Plasmas 6, 4722 (1999)] plasmas and (circularized) DIII-D-like [Fusion Technol. 8, 441 (1985)] discharges. Global gyrokinetic particle simulations and reduced MHD calculations respe ctively show that ion temperature gradient driven turbulence (ITGDT) and re sistive internal kink MHD activity can be reduced and/or suppressed with ex perimentally achievable externally imposed flows for possible ET start-up p lasmas. Global gyrokinetic particle simulations of ITGDT also serve to demo nstrate that self-generated flows are necessary to yield experimentally rel evant radial correlation lengths in the case of DIII-D-like discharges. (C) 2000 American Institute of Physics. [S1070-664X(00)90305-7].