Effect of Resonant Magnetic Perturbations on 3D equilibria in the MST RFP

The orientation of 3D equilibria in the MST RFP can now be controlled with application of a resonant magnetic perturbation (RMP). This control has led to improved diagnosis revealing enhancements in both the central electron temperature and density. Coupled to a recent advance in the V3FIT code, reconstructions of the 3D equilibria have also been improved. The RMP also inhibits generation of high-energy (\textgreater 20keV) electrons, which are otherwise produced with the 3D state. This state occurs when the normally broad spectrum of core-resonant m $=$ 1 tearing modes condenses, with the innermost resonant mode growing to large amplitude $\sim$ 8{\%} of the axisymmetric field. As the dominant mode grows, eddy current in MST's conducting shell slows the mode's rotation, eventually leading to locking of the 3D structure. An m $=$ 1 RMP with an amplitude br/B $\sim$ 10{\%} can force the 3D structure into any desired orientation relative to MST's diagnostics. Reduced stochasticity and improved confinement of high-energy electrons during the formations of the 3D structure are observed. This work is supported by the US DOE.