Effect of drift modes on current free plasma transport processes in a stellarator

The authors measure the losses of charged particles and heat via the electrons in the toroidal l=3 Saturn stellarator with large shear (thetasub(max)less than or approximately equal to0.25). From an analysis of the relationships derived they conclude that the pseudoclassical nature of the energy losses observed is due to the presence of drift modes in plasma. The particle losses for shear theta<0.05 are determined by the turbulence of the plasma, whereas at theta<0.05 the diffusion both in magnitude and functional dependence matches the neoclassical theory. (author)