Progress towards steady-state advanced scenarios in ASDEX Upgrade

Recent experiments at ASDEX Upgrade have concentrated on advanced scenarios, specifically ELMy H-mode discharges without an internal transport barrier which obtain a high beta(N) = 3.5 in steady state. A highly shaped plasma configuration is used at 800 kA, with a triangularity 8 = 0.42 and edge safety factor, q(95), in the range 3.6-4.1. The product beta(N)H89-P reaches up to 8.0 in plasmas approaching a stationary conditions, and beta(N)H89-P = 11.5 is achieved transiently. These discharges are at high density, 80-90% of the Greenwald density limit. Discharges at the highest density show a strong reduction of the ELM activity, similar to type II activity, eliminating transient high heat loads on the divertor target. Finally, the non-inductively driven current approaches 70% of the total current making this regime a serious candidate for an advanced scenario in a reactor, and a benchmark for other advanced scenarios.