Turbulence-driven heavy ion transport in hot magnetized plasma is investigated by means of the gyrokinetic theory and simulations. A finite heavy ion parallel compressibility pinch (Γ_{s,∥}) is found ...in the gyrokinetic framework, in contrast to the conventional understanding that Γ_{s,∥} is negligible. A perturbation theory clarifies the turbulence frequency dependence of Γ_{s,∥}, resolving the discrepancy with experimental observations. It is also predicted by a nonlocal approach of the parallel advection term that Γ_{s,∥} is strongly anisotropic on a magnetic surface. The parameter dependence shows that decreasing the heavy ion mass m_{s} strongly enhances Γ_{s,∥} through kinetic effects, leading to a deviation from the 1/m_{s} scaling. Moreover, the pinch direction can be reversed in nonlinear trapped electron mode turbulence through the inverse cascade.
A theory for describing collisionless long-time behavior of zonal flows in helical systems is presented and its validity is verified by gyrokinetic-Vlasov simulation. It is shown that, under the ...influence of particles trapped in helical ripples, the response of zonal flows to a given source becomes weaker for lower radial wave numbers and deeper helical ripples while a high-level zonal-flow response, which is not affected by helical-ripple-trapped particles, can be maintained for a longer time by reducing their bounce-averaged radial drift velocity. This implies a possibility that helical configurations optimized for reducing neoclassical ripple transport can simultaneously enhance zonal flows which lower anomalous transport.
PDF
