ENHANCED CONFINEMENT WITH PLASMA BIASING IN THE MST REVERSED-FIELD PINCH

We report an increase in particle confinement with plasma biasing in a reversed field pinch. Miniature plasma sources an used as electrodes to negatively bias the plasma at the edge (r/a similar to 0.9). Partic le content increases and H-alpha radiation decreases upon application of bias and global particle confinement roughly doubles as a result. E nergy confinement is not significantly affected by biasing the edge. M easurements of plasma potential, impurity flow. and floating potential fluctuations indicate that strong flows are produced and that electro static fluctuations are reduced.