COMPLETE INTEGRAL SUPPRESSION OF PFIRSCH-SCHLUTER CURRENT IN A STELLARATOR PLASMA IN HELIOTRON-E

The poloidal magnetic field was measured to detect the plasma boundary position. It was found that the pressure-induced plasma shift, an obs ervable characteristic of the Pfirsch-Schluter current, depends strong ly on the initial position of the magnetic axis. When the axis was mov ed by the vertical field inside the torus, the finite-beta shift becam e smaller. Complete suppression of the finite-beta plasma shift was ac hieved in a deeply inward shifted configuration: 7 cm from the standar d position R-axis = 2.20 m. This effect is explained by magnetohydrody namic (MHD) equilibrium theory for stellarator toroidal plasmas with a large magnetic hill and deep inward shift. (C) 1998 American Institut e of Physics.