Ten years of operation and developments on Tore Supra

Tore Supra started operation 10 years ago, on April 1, 1988. This tokamak, today the third in size world wide, has several features representative of the needs of future fusion power production devices: it is equipped with superconducting toroidal field coils (NbTi cooled with He II at 1.8 K); actively cooled plasma facing components; non-inductive current drive systems and real time feedback systems for plasma control. These features provide unique capabilities for achieving high-performance long-pulse plasma discharges and studying several key physics issues in truly steady-state conditions. Several key experimental achievements could thereby be obtained, such as: (i) steady-state high bootstrap fraction discharges (IBS/Ip>50%, ≥5 s); (ii) long discharges sustained by non-inductive current drive, with enhanced confinement, in particular, 2 min discharges, with up to 280 MJ of energy coupled to the plasma, and fully non-inductive steady-state discharges held for duration of up to 70 s; (iii) highly radiating discharges with Prad/Ptot>60±10% and confinement as good as the ELMy H-Mode selected for ITER. These results could be achieved thanks to a tight integration between physics and technology. In line with these achievements, Tore Supra is now preparing its evolution, with the CIEL project, which aims at renewing the inner components of the machine. This should bring the overall power handling capability up to about 25 MW, with plasma facing components able to sustain power densities in the 10 MW m−2 range. The pulse length capability of the tokamak should reach 1000 s.