Progress toward steady-state operation on tore supra

Important technological and physics issues related to steady-state operation required for next step are being examined on Tore Supra, after a major upgrade of internal components in order to increase the heat extraction capability to 25 MW for 1000 s. Here, we show first experimental results, where all the plasma facing components were actively cooled during pulses exceeding four minutes, with reactor-relevant heat load. New physics was observed in non-inductively driven plasmas, including a stationary peaked radial profile of the plasma density generated by an anomalous inward pinch; and a regime characterized by sinusoidal oscillations of central electron temperature, governed by non-linear coupling between heat transport and plasma current analogous to a predator-prey mechanism. (authors)