Effect of rigid rotation on the stability to external kink modes

The effect of rigid toroidal rotation on the stability of a tokamak to external kink modes is examined. The effect of rigid rotation is modeled by a centrifugal force field. The problem is studied in the cylindrical limit for which this reduces to a uniform force field acting in a direction transverse to the plasma column. The effect of a transverse force field on the limit on the safety factor q for stability to external kink modes is studied. For values of q above this, limits on the plasma beta, denoted β, are obtained. A study of the equilibrium of a toroidal plasma undergoing rigid toroidal rotation yields another limit on β as a function of q. Combining the results of cylindrical stability with that of toroidal equilibrium provides approximate estimates of the maximum β that could be obtained. The effect of rigid rotation on this maximum β is also studied