Plasma flow in MST: Effects of edge biasing and momentum transport from nonlinear magnetic torques

Edge biasing in MST plasmas decreases electrostatic turbulent particle tran sport and increases the global particle confinement time. New Langmuir prob e measurements in the edge identify decreased electric field fluctuations a nd increased anti-correlation of density and potential fluctuations to be r esponsible. Fast loss of momentum in the core of MST during sawtooth crash events can be explained as a result of nonlinear magnetic torques which all ow viscous coupling over relatively distant regions of the plasma. Flow mod ifications resulting from biasing, plus other experiments, help reveal the nonlinear nature of this process, most directly measured by the triple prod uct bispectral correlation between the nonlinearly interacting modes.