Resistivity Studies in NSTX using TRANSP*

It is typically assumed that in NSTX plasmas neoclassical is the appropriate model to describe the plasma resistivity. However, recent findings have shown that for NSTX L-mode plasmas with reversed magnetic shear (RMS) safety factor (q(r)) profiles, the classical or Spitzer model is more appropriate. This was found via comparison between magnetic pitch angles measured by the motional Stark effect (MSE) diagnostic and those predicted by the transport model TRANSP. In those results, pitch angles predicted using the Spitzer model produced a better match to the data in the core of the plasma through the current ramp and into the flattop. Here, we extend those results to include NSTX H-mode plasmas. We find that in general Spitzer produces a better match to the measured pitch angles, though there are regions in the plasma in which predictions made using neoclassical resistivity are in better agreement. This suggests that Spitzer is the more appropriate resistivity model to use for NSTX plasmas.