Impact of the wall conditioning program on plasma performance in NSTX

Abstract High performance operating regimes have been achieved on NSTX through impurity control and wall conditioning techniques. These techniques include HeGDC-aided boronization using deuterated trimethylboron, inter-discharge HeGDC, 350 °C PFC bake-out followed by D 2 and HeGDC, and experiments to test fueling discharges with either a He-trimethylboron mixture or pure trimethylboron. The impact of this impurity and density control program on recent advances in NSTX plasma performance is discussed.