Progress to long pulse operation in Tore Supra

Tore Supra has been operated at its nominal current and toroidal field. A multipellet injector was successfully tested and could maintain a 4 x 1019 m-3 quasi-stationary density with up to 25 pellets. The modification of the plasma boundary conditions by a pump limiter or an ergodic divertor has been investigated. Lower hybrid waves with powers of up to 3.8 MW have been launched, driving up to 80% of the total current and, thus, extending the plateau current up to 22s. The time constants involved in the control of steady state plasmas (heat, particle, current diffusion) are discussed. (author). 5 refs, 3 figs