Significant results on steady state control of the plasma parameters have been obtained with RF systems on Tore Supra. A sustained effort is under way to improve power transmission reliability. Developments of sources and antennas are in progress for future operation on Tore Supra with purse length in tile range of several hundreds of seconds.

Recent Tore Supra results supporting the feasibility of high-confinement. long duration discharges are reported. Two-minute discharges with improved confinement have been obtained. This progress is largely due to improvements in the operating control system of Tore Supra. which now allows real-rime feedback control of global plasma parameters. A clear correlation between improved confinement and current profile shape has been established. Transport barriers for electron heat diffusion are observed in experiments where the magnetic shear is weak or negative in the central part of the plasma. These observations strongly support development of new current drive schemes for current profile control. Considerable progress concerning particle and heat exhaust has also been achieved. A new technique allowing conditioning in the presence of a toroidal magnetic field has been implemented. A vented limiter has been tested as a means of particle exhaust through collection of neutrals, and its performance is compared with that of a "classical", ion collecting throat limiter. The knowledge gained from extensive long pulse experimentation has been used to develop a new generation of plasma facing components. which will permit further development of the long discharge capability of Tore Supra.

A first conceptual antenna design based on the passive-active multijunction (PAM), was proposed in 93 in the frame of an ITER-TASK [1]. The present work accounts for the dimensional change of the ITER ports and also proposes a new arrangement of the hyperguides feeding the PAM to allow the flexibility of the N// spectrum which is desirable to cover the variety of envisioned scenarios. 35 to 55 MW of LH power could be injected in 1 port of ITER depending on the actual plasma reflection coefficient.

Recent stationary improved confinement experiments with current density profile modifications in non-inductive Tore Supra operation are reported. Significant progress has been obtained by achieving long duration discharges using lower hybrid (LH) waves: (i) 2 min in the 4 T improved confinement LHEP (LH enhanced performance) regime, H-RLW = W-e/W-e-RLW = 1.6 at a current I-p = 0.8 MA, loop voltage V-1 approximate to 0.1 V, LH power P-lh = 2.5 MW (W-e, W-e-RLW are the electron energy content and Rebut-Lallia-Watkins L-mode prediction), (ii) 75 s long in a fully non-inductive LHEP regime (H-RLW = 1.4, V-1 = 0 V, I-p approximate to 0.62 MA, P-lh approximate to 3.0 MW) using a new plasma control scheme, (iii) 30 s at 1.7 MA (V-1 approximate to 0.25 V, P-lh = 2.5 MW) in the L-mode regime. MHD stability in full current drive operation and the role of weak-or reversed-central magnetic shear in the central LHEP electron temperature transition (reproduced in full current drive in a systematic manner and measured by independent electron temperature diagnostics) are discussed.Stationary high-beta(p) experiments were performed with fast-wave direct electron heating (FWEH) in a large range of operation: 42-76 MHz and B-t = 2-3.9 T. Maximum coupled power of 9.5 MW is obtained in the 48 MHz/2T configuration with good electron heating performance and improved confinement at high density (central density of approximate to 6 x 10(19) m(-3)). By increasing the magnetic shear in the gradient region, stationary improved confinement states (6 MW during 5 s, H-RLW approximate to 2.2) are reached in a reproducible manner with poloidal beta, beta(p), approaching 1 and 40% of bootstrap current.The high-bootstrap FWEH experiments have been recently combined with LHCD at reduced loop-voltage (less than or equal to 0.1 V and up to 70% of non-inductive current). A total injected power up to 7.2 MW (LH: 3.6 MW, FW: 3.6 MW) has produced stationary improved confinement with a peaked electron temperature profile (central value up to 8.0 keV) at a central density of 3.9 x 10(19) m(-3).

In view of high-power, long-pulse steady-state operation, Tore Supra has incorporated in its design the active control of heat and particles in a realistic environment. In the early experimental phase of Tore Supra, the first generation of plasma-facing components was tested, and these tests provided much physics and technological information and illuminated various operational difficulties. In particular, these experiments revealed the weakness of the graphite-to-metal brazing process originally adopted for actively cooled high-heat-flux components. Consequently, a new inner-wall technology was developed in 1994 and is to be tested in 1995-1996 with a totally rebuilt 40-deg toroidal sector. A carbon-fiber-reinforced carbon-metal compound is based on the newest brazing technology and rigorous quality control. Components such as the toroidal pump limiter and the guard limiters of plasma-heating antennas are being developed in the same way. For structures where brazing is difficult, boron carbide-coated components have been developed and installed in Tore Supra. For lower heat fluxes, a bolted concept has been designed and tested. The influence of inner-first-wall misalignment in Tore Supra on the power exhaust limitation of brazed components has been studied.Results from the technological development for the different power exhaust systems and the associated experimental knowledge obtained during plasma operation in Tore Supra are presented.

The link between the current profile and the confinement is studied, involving various regimes: high power minority ion cyclotron resonant heating, high power lower hybrid current drive, fast wave direct electron heating and current drive and pellet enhanced performance. It is shown that the electron heat diffusivity decreases when the magnetic shear increases in the confinement zone and/or when it decreases in the plasma center.