Generalized banana-drift transport

The theory of tokamak ripple transport in the banana-drift and ripple-plateau regimes is extended in a number of directions. The theory is valid for small values of the toroidal periodicity number n of the perturbation as well as for the moderate values (n approx.= 10-20) previously assumed. It is shown that low-n perturbations can produce much greater transport than the larger-n perturbations usually studied. In addition, the ripple perturbation is allowed arbitrary values of poloidal mode number m and frequency ω, making it applicable to the transport induced by MHD modes. Bounce averaging is avoided, so the theory includes the contributions to transport from all harmonics of the bounce frequency, providing a continuous description of the transition from the banana-drift regime to the ripple-plateau regime. The implications of the theory for toroidal rotation in tokamaks are considered. (author)