Effects of plasma parameters on viscosity

A numerical code is developed to study the effect of ion density and temper ature (as well as ion pressure and temperature gradients) on the amplitude of the local maxima of the poloidal viscosity with respect to the poloidal Mach number using the model developed by Shaing [1]. The sum of the poloida l viscosity and ion-neutral collisions is determined from the dependence of the plasma radial current on the radial electric field in a biased electro de experiment. The experimental results in the interchangeable module stell arator agree qualitatively with the predictions of the numerical calculatio n regarding the effects of variation of ion density and temperature on visc osity.