Turbulence suppression in plasmas around the Greenwald density limit on EAST and DIII-D

Recent high poloidal beta (βP) scenario experiments on EAST and DIII-D have made coordinated breakthroughs for high confinement quality at high density near the Greenwald limit. Experiments on EAST have nearly doubled the ion temperature at normalized density (fGr) ~0.9, overcoming a long standing limitation in long pulse operations. Experiments on DIII-D have achieved fGr above 1 simultaneously with normalized confinement (H98y2) well above 1, as required in fusion reactor designs but never before verified in experiments. Density gradient amplification of turbulence suppression at high βP can explain both of these achievements. EAST long pulse H-mode experiments have reached a world record duration of 400 seconds, but with Ti<