Objective The programme fits into the pattern of priorities of the European fusion programme and will make a considerable contribution of the definition of the "next step". Operation of TORE SUPRA will be the main activity of the Association, but participation in the JET Joint Undertaking will remain substantial, and the studies associated with the definition of NET will be extended during this period. The EURATOM/CEA Association will, moreover, provide an important contribution to the European technological research programme, hence enabling the Community to benefit from the very broad range of skills and research resources at the disposal of the CEA.Weakly damped lower hybrid wave propagation is shown to be chaotic for parameter regimes typical of current drive in Tore Supra and JT-60. In these cases, the spectral gap is filled by wave energy that difuses to higher k (parallel) in the stochastic layer. Agreement between theoretical and experimental scalings for the current drive efficiency is obtained by including nonresonant losses of wave energy, due to collisions and lossy reflections near the plasma edge, which reduce the efficiency at low temperatures, when the spectral gap is large.The performance of a grazing incidence (85 degree) violet ultraviolet duochromator using 2 proximity focused metallic multianode microchannel plate detectors is described. The system, using standard photon counting techniques directly on the array of 10 straight anodes, has a total coverage of 5 to 230 nm, with 0.13 nm (one anode) spectral resolution; each detector (centred on the Rowland circle and mounted perpendicularly to the diffracted ray) covers a 1.33 nm region, the spectral range being independent of the central wavelength value. A maximum permissible counting rate of 2E6 Hz has been obtained, thus allowing sub ms time resolution. Examples of the operation of this system on the Tore Supra tokamak are described.The particle collection characteristics of the Tore Supra outboard pump limiter (OPL) are studied in order to assess and understand the effects of the plasma parameters on the performance of the OPL module.The results of 2 series of experiments, one in plasmas with ohmic heating and one in plasmas with lower hybrid heating, are analysed, and the general trend of the module particle collection is evaluated by studying the OPL conductance parameter in plasmas with various densities, temperatures, heating power, and impurity behaviour. For this study, the contribution from the impurity carbon influx to the OPL is taken into account in estimating the hydrogenic ion particle influx obtained from the Langmuir probes located inside the OPL entrance throat.The results presented here indicate that molecular gas conductance plays the principle role in the particle collection performance of the OPL for local densities up to 4E12 per cubic centimetre. This observation is consistent with the fact that the ionization mean free path of the outstreaming neutrals is comparable to the throat length of the module for the density and the electron temperature available in the throat.Thermal hydraulics tests were carried out in order to find a cooling method capable of removing the high heat fluxes expected for the NET/ITER divertor. The goal was to evaluate, by experiments, the critical heat flux (CHF) and heat transfer in the subcooled boiling regime using twisted tapes as turbulence promoters and testing them under relevant thermal-hydraulic conditions.The CEA 200 kW electron beam facility and the 10 MW JET neutral beam test bed were used to heat up the NET relevant test sections consisting of rectanglar copper elements, with circular internal channels. The test sections were exposed to the electron or ion beams under normal incidence. The results of the experiments and of thermal analyses performed in support of the tests are given. The experimental CHF values were benchmarked with the Tong-75 correlation.The thermal confinement within the confinement zone (values of q in the approximate range 1 to 2) of Tore Supra ohmically heated deuterium plasmas bounded by the ergodic divertor (ED) configuration is studied in a 1.5 dimensional analysis of the local power balance. Although the edge electron temperature and mean electron density are both on average halved with application of the ED, the mean electron thermal diffusivity shows the same density dependence as exhibited by standard ohmic limiter discharges, ie, an Alcator-like inverse dependence on the mean electron density at low density (where the mean electron thermal diffusivity is of the order of 2.5E19 divided by the mean electron density), and a saturation at high density.The ion thermal transport at low to medium densities in both limiter and ED discharges is between 10 to 20 times that predicted by neoclassical theory. Comparing ED and limiter plasmas of the same density, a strong plasma decontamination is observed with a reduction in z(effective) by between 1.0 to 1.5. The effective decoupling of the mean electron density and z(effective) by the ED and the invariant behaviour of the mean electron thermal diffusivity imply that the electron thermal transport is only weakly dependent on z(effective) in ohmic Tore Supra discharges.The diffusive motion of charged particles in a stochastic magnetic field is investigated systematically in a model in which the statistics of both the collisions and the magnetic field are described by coloured noises characterized, respectively, by a finite correlation time and finite correlation lengths. An analytic solution is obtained for the basic nonlinear differential equation of the model. It describes asymptotically a pure diffusion process, in which the mean square displacement in the perpendicular direction, grows proportionally to time. The corresponding diffusion coefficient scales as the fourth power of the magnetic fluctuation intensity. The values obtained are in very good agreement with experimental data in reverse field pinch experiments. The present result contradicts earlier results predicting subdiffusive behaviour. A detailed comparison between these 2 sets of results is presented.History of Association/Laboratory- Created in 1958 as Service de Recherches sur la Fusion Contrôlée.- Operated the TFR Tokamak at Fontenay aux Roses for 11 years.- PETULA and WEGA were constructed and operated at Grenoble.- Research Unit moved to Cadarache in 1984-1986.- First operation of TORE SUPRA in April 1988.Present scientific and technical programme- Operate the TORE SUPRA superconducting Tokamak- Investigate long pulse operation in quasi steady state discharge- Prepare the next step : . supraconducting magnet development . plasma facing components . (ergodic) divertor physics . negative ion beam development . current drive and current profile optimization . tokamak system operation and control Staff : Professionals 200 Support staff 210 Yearly budget (expenditure 1994) about 58 Mio ECU Management StructureHead of Research Unit: D. ESCANDEDeputies: B. GOUDAL, R. GRAVIER (ITER Team), M. CHATELIERSTEP Head: J.L. CARBONNIERDeputy: F. PARLANGESTID Head: G. TONONDeputies: J.G. WEGROVE, B. TURCKSPPF Head: B. SAOUTICDeputy: M. GREGOIRESTPF: E. MASCHKE Collaboration with other institutionsEcole Polytechnique (Palaiseau): Coherent laser scatteringUS/DOE (ORNL, SNL): Heat removal and particle controlG.A.: Current drive and divertor studiesJAERI (Naka): Negative ion beamsJET (Abingdon): Current profile control Programme(s) EAEC-FUSION 12C - Specific programme of research and training in the field of controlled thermonuclear fusion, 1994-1998 Topic(s) Data not available Call for proposal Data not available Funding Scheme Data not available Coordinator Centre d'Etudes de Cadarache EU contribution No data Address 13108 Saint-Paul-lez-Durance France See on map Total cost No data
