Enhanced particle transport events approaching the density limit of the J-TEXT tokamak

Abstract Enhanced particle transport events are discovered and analyzed as the density limit of J-TEXT tokamak is approached. Edge shear layer collapse observed ratio Reynolds power to turbulence production decreases. Simultaneously, divergence internal energy flux (i.e. spreading) increases, indicating that triggers an outward spreading event. Studies correlations show enhanced quasi-coherent, manifested primarily in fluctuations which exhibit positive skewness. Electron adiabaticity emerges critical parameter signals event onset. For α < 0.35 approaches Greenwald density, both rise rapidly. Taken together, these results elucidate connections between edge layer, fluctuations, events, plasma cooling