MHD and kinetic dynamo activities and confinement in the reversed field pinch experiment on TPE-1RM15

In the reversed field pinch experiment on TPE-1RM15, three kinds of limiter material (stainless steel, graphite and molybdenum) are studied. In the present operating region, molybdenum gives the best results. The central electron temperature (Te(0)) and the density increase linearly with the plasma current (Ip) up to 200 kA. The highest electron temperature of about 1 keV and a density of about 3x1019m-3 are obtained. The heat flux of the high energy electron flow (HEEF) in the boundary region is estimated to be about 500 MW/m2 from the increase in the bulk temperature and the variation of the surface temperature of the movable graphite limiter. A high energy component of about 10 keV is observed in HEEF. The power loss fraction associated with HEEF is about 50-70%. The detailed mechanism of the MHD dynamo becomes clear where toroidally localized distortions of m=1 and m=0 modes are observed. It is found that Vloop depends weakly on Ip and Te(0). The Vloop anomaly related to the dynamo activity is estimated to be about 10-15 V. (author). 14 refs, 6 figs