Stationary H-mode discharges with internal transport barrier on ASDEX upgrade

Stationary discharges with H-mode edge and internal transport barrier for e nergy, momentum, and particle transport have been obtained on ASDEX Upgrade . At a line averaged density of 4 x 10(19) m(-3) an H factor of HITER89-P = 2.4 and beta(N)=2 could be maintained for 6 s corresponding to 40 confinem ent times, limited only by the possible discharge duration. The q profile i s hat in the center and close to 1. Current diffusion calculations suggest that reconnection is required to clamp the safety factor at 1, which in the absence of sawteeth is explained by the strong fishbone activity.