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

A recent study conducted on the Madison Symmetric Torus reversed-field pinch has shown that control of density fluctuations can be achieved through modification of the current density profile. Most of the power in the density fluctuations is directly associated with core-resonant resistive tearing modes. We report that, during auxiliary current drive experiments, these density fluctuations are reduced about an order of magnitude over the entire plasma cross section and the resulting electron confinement is increased eightfold.