Control of density fluctuations and electron transport in the reversed-field pinch

A recent study conducted on the Madison Symmetric Torus reversed-field pinc h has shown that control of density fluctuations can be achieved through mo dification of the current density profile. Most of the power in the density fluctuations is directly associated with core-resonant resistive tearing m odes. We report that, during auxiliary current drive experiments, these den sity fluctuations are reduced about an order of magnitude over the entire p lasma cross section and the resulting electron confinement is increased eig htfold.