Interactions between neoclassical effects and turbulence in toroidal momentum transport, and comparison between flux driven and gradient driven simulations

Idomura, Yasuhiro   

Comparisons between flux driven full-f gyrokinetic simulations and gradient driven delta-f gyrokinetic simulations are discussed with respect to i) turbulent momentum transport and ii) plasma size and power scaling of ion temperature gradient driven turbulence. In the former problem, the ambipolar condition including both turbulent and neoclassical transport is essential in estimating momentum transport and resulting plasma rotation profiles. In the latter problem, self-consistent interactions between temperature fluctuations and turbulent transport under a local power balance condition lead to the power degradation of confinement. These mechanisms are unique to full-f simulations and give significant impact on the estimation of plasma confinement performances.