Minority Ion Cyclotron Current Drive in Tokamaks

Abstract

Current profile control by minority ion cyclotron current drive is a method to stabilize sawtooth instabilities in future tokamak reactor experiments. Ion cyclotron current drive has previously been treated as a diffusion in velocity space only. In a toroidal plasma, the waves induce diffusion in real space as well as in velocity space. In combination with the finite deviation of the drift orbits from a magnetic flux surface, this gives rise to new current drive mechanisms. These mechanisms are found to be the dominating ones for minority ion current drive with high power and at high temperature.