Physics issues of compact drift optimized stellarators

Physics issues are discussed for compact stellarator configurations which a chieve good confinement by the fact that the magnetic field modulus \B\ in magnetic co-ordinates is dominated by poloidally symmetric components. Two distinct configuration types are considered: (1) those which achieve their drift optimization and rotational transform at low beta and low bootstrap c urrent by appropriate plasma shaping; and (2) those which have a greater re liance on plasma beta and bootstrap currents for supplying the transform an d obtaining quasi-poloidal symmetry. Stability analysis of the latter group of devices against ballooning. kink and vertical displacement modes has in dicated that stable beta values on the order of 15% are possible. The first class of devices is being considered for a low beta near term experiment t hat could explore some of the confinement features of the high beta configu rations.