MHD-induced Fast Ion Loss from NSTX Plasmas

The Scintillator Fast Lost Ion Probe (sFLIP) on NSTX measures the loss of neutral beam ions lost to the wall near the outer midplane, resolved in gyroradius and pitch angle. The diagnostic has recently been upgraded to record the characteristics of the loss at up to 40,500 frames/s, allowing resolution of losses arising from MHD activity. That loss is often at high pitch angle. Fast ion loss correlated with field error correction and resistive wall mode control fields has also been observed.