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Bibet, P.; Crenn, J.P.
Association Euratom-CEA, Centre d'Etudes de Cadarache, 13 -Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee1992
Association Euratom-CEA, Centre d'Etudes de Cadarache, 13 -Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee1992
AbstractAbstract
[en] New types of antennas, based on quasi-optical propagation, are considered for heating large Tokamaks (JET, ITER) at the lower hybrid frequency. The use of quasi-optical techniques in these antennas allows to compete with waveguides used up to now. Two types of LHW launchers are studied in which the radiating antenna is associated to a grill composed of either a waveguide array or a diffraction rod array. The first type leads to low power transmission values. In the second type, Gaussian beams are launched by radiating antenna in order to have a smaller angle of divergence improving the emission. More thorough theoretical and experimental studies are needed, to make this concept more precise and to compare it to LHW launchers based strictly on waveguide concept
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Jan 1992; 60 p
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Report
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Chantant, M.; Beaumont, B.; Bibet, P.; Ekedahl, A.; Martinez, A.; Vallet, J.C.
CEA Cadarache, Dept. de Recherches sur la Fusion Controlee, 13 - Saint-Paul-lez-Durance (France)2004
CEA Cadarache, Dept. de Recherches sur la Fusion Controlee, 13 - Saint-Paul-lez-Durance (France)2004
AbstractAbstract
[en] One particularity of Tore Supra is that the Plasma Facing Components (PFCs) are actively cooled, allowing research on long duration and high energy discharges. During a discharge, a large part of the energy is dissipated in the heating generators (ICRH, ECRH and LHH) and auxiliaries. It is transferred to the primary cooling loops (B50 and B60). The energy which is injected in the plasma is totally recovered by the PFCs primary cooling loop B30. The primary loops are cooled via heat exchangers by a secondary loop. The previously existing limitations of the complete Tore Supra cooling system were due to the heat exchange performance to the secondary loop. From 2001 to 2003, the various primary loops have been upgraded and during the 2003 experimental campaign, significant results were obtained, particularly during non inductive discharges with an injected energy by the Lower Hybrid Current Drive (LHCD) system of up to 1.1 GJ. For the long and high energy discharges, the agreement between the energy measured by the calorimetry on the PFCs cooling loop and the HF energy is very good (90 to 95%). Furthermore, calorimetry measurements on the various cooling loop allow to assess the global operation of the cooling system. (authors)
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2004; 7 p; 23. symposium on fusion technology; Venice (Italy); 20-24 Sep 2004; 3 refs.
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Miscellaneous
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Conference
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Bibet, P.; Litaudon, X.; Moreau, D.
Association Euratom-CEA, Centre d'Etudes Nucleaires de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee1994
Association Euratom-CEA, Centre d'Etudes Nucleaires de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee1994
AbstractAbstract
[en] A new concept - the reflector waveguide array - is proposed to improve and simplify the design of c.w. Lower Hybrid launchers for steady-state reactor applications. Mechanical robustness of the antenna and efficient heat removal are provided by a thick-wall waveguide structure which can accommodate a large number of cooling ducts. It is shown that the coupling properties of an array and the directivity of the radiated power spectrum are similar to the ones of present day launchers. Their dependences upon the depth of the reflector waveguides, and the electron density and its gradient are investigated. The effect of changing the phase between the drivers is also studied. The proposed reflector LH antenna would provide enough flexibility to vary the N spectrum for plasma control purposes in a steady-state fusion reactor. (author). 10 refs., 24 figs
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Sep 1994; [38 p.]; Submitted to Nuclear Fusion (AT).
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AbstractAbstract
[en] Tore Supra is a limiter tokamak with circular plasma cross-section. The superconducting toroidal magnet is a unique feature which allows very long pulse discharge. Tore Supra has ion cyclotron resonance heating and an electron cyclotron system is being installed.Non-inductive currents are driven by lower hybrid and by the bootstrap effect.Highlights of previous results include long pulses lasting up to 2 minutes with 280 MJ coupled into the plasma and fully non-inductive discharges lasting up to 75 seconds. Tore Supra is presently in the middle of a major shutdown for the installation of a new toroidal pumped limiter. This will be actively cooled with capability for steady state operation at total power levels around 20 MW. Future plans include upgrades to the ion cyclotron heating and lower hybrid current drive systems and new pellet injector
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Journal Article
Journal
Voprosy Atomnoj Nauki i Tekhniki. Plazmennaya Ehlektronika i Novye Metody Uskorenia; ISSN 1681-3081; ; (no.3/5/); p. 28-32
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Bibet, P.; Achard, J.; Berger By, G.; Goniche, M.; Magne, R.; Capitain, J.J.; Rey, G.; Tonon, G.; Litaudon, X.; Moreau, D.
Association Euratom-CEA, Centre d'Etudes Nucleaires de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee1990
Association Euratom-CEA, Centre d'Etudes Nucleaires de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee1990
AbstractAbstract
[en] The main characteristics of the Tore Supra lower hybrid antenna are discussed. In order to know the antenna's RF behavior, it is necessary to know the incident and reflected fields in each waveguide, when some of them are known. To solve this problem, the relations which link each electric field to the others are given by the knowledge of the scattering matrix of the antenna. The methods for finding the scattering matrix are given. The self-matching of the output reflexion coefficient of Tore Supra lower hybrid antenna is measured and calculated. The determination of the scattering matrix allowed determining the coupling coefficient of the modules in front of the plasma. Good agreement between theoretical and experimental data is found
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Mar 1990; 99 p
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Report
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AbstractAbstract
[en] A 8 MW - quasi continuous - 3.7 GHz Lower Hybrid Heating system is being designed for mainly current-drive studies on the TORE SUPRA Tokamak. A large simplification of the L.H. antenna and of the RF transmission line is obtained by applying two main ideas: (i) modular design, (ii) internal RF power division - 3 dB hybrid junction and E-plane multijunction. The E-plane M.J system brings not only simplification in the building of the antenna, but also, when used in travelling wave, lowers strongly the power reflection coefficient towards the generator. This is a very important point, because such a system allows to avoid the use of circulators - expensive elements for large machine
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Association Euratom-CEA, Centre d'Etudes Nucleaires de Cadarache, 13-Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee; 54 p; May 1986; p. 37-40; 13. European conference on controlled fusion and plasma heating; Schliersee (Germany, F.R.); 14-18 Apr 1986
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Report
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Conference
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AbstractAbstract
[en] A new concept - the reflector waveguide array - is proposed to improve and simplify the design of continuous wave lower hybrid (LH) launchers for steady state reactor applications. Mechanical robustness of the antenna and efficient heat removal are provided by a thick wall waveguide structure that can accommodate a large number of cooling ducts. The plasma facing mouthpiece could be made of the same material as the reactor first wall and could be easily replaceable through remote handling. In order to compensate for the increased horizontal distance between adjacent waveguides, the front ends of the thick septa are grooved to form short (approx.= λ/4) passive waveguides that act as reflectors between the radiofrequency powered waveguides (drivers). Then, for an adequate phasing between the active waveguides, the total electric field at the reflector waveguide apertures varies coherently with the one in the drivers to launch a highly directional slow wave. It is shown that the coupling properties of such an array and the directivity of the radiated power spectrum are similar to those of present day launchers. Their dependences upon the depth of the reflector waveguides, and the electron density and its gradient are investigated. The effect of changing the phase between the drivers is also studied. The proposed reflector LH antenna would provide enough flexibility to vary the Nparallel spectrum for plasma control purposes in a steady state fusion reactor. (author). 11 refs, 24 figs
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Journal Article
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Numerical Data
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Litaudon, X.; Bibet, P.; Goniche, M.; Bergerby, G.; Bizarro, J.P.; Capitain, J.J.; Hoang, G.T.; Magne, R.; Moreau, D.; Peysson, Y.; Rax, J.M.; Rey, G.; Tonon, G.
Association Euratom-CEA, Centre d'Etudes Nucleaires de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee1991
Association Euratom-CEA, Centre d'Etudes Nucleaires de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee1991
AbstractAbstract
[en] The TORE SUPRA Lower Hybrid Current Drive experiments (8 MW/ 3.7GHz) use large phased waveguide arrays (4 rows of 32 waveguides for each of the two grills) to couple the waves to the plasma. These launchers are based on the Multijunction principle which allows them to be quite compact but needs to be fully assessed for the design of efficient multi-megawatt antennas in NET/ITER. Extensive coupling measurements have been performed to study the Radio-Frequency characteristics of the plasma loaded multijunction antennas. The experimental data have been related to the output of the linear coupling theory which, in its advanced stage, takes into account the specific features of the compact launchers. The measurements, scattering matrices and power reflection coefficients, are in perfect agreement with the theoretical simulations performed with the measured edge plasma density. Our analysis leads to the determination of the n parallel radiated spectra. We demonstrate that the n parallel flexibility is obtained in a large range of edge plasma densities (or antenna positions) while preserving an optimum behaviour of the antenna. Finally, the Multijunction launcher has proved to be able to transmit high RF powers since power densities up to 45MW/m2 have been reached with good linear coupling characteristics and spectrum control
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1991; 4 p; 18. EPS Conference on Controlled Fusion and Plasma Physics; Berlin (Germany); 3-7 Jun 1991
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AbstractAbstract
[en] The TORE SUPRA Lower Hybrid Current Drive experiments (8MW/3.7GHz) use large phased waveguide arrays (4 rows of 32 waveguides for each of the two 'grills') to couple the waves to the plasma. These launchers are based on the 'Multijunction' principle which allows them to be quite compact but needs to be fully assessed for the design of efficient multi-megawatt antennas in NET/ITER. (author) 5 refs., 6 figs
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18. European conference on controlled fusion and plasma physics; Berlin (Germany); 3-7 Jun 1991
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Journal Article
Literature Type
Conference; Numerical Data
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Europhysics Conference Abstracts; ISSN 0378-2271; ; CODEN ECABDW; v. 15C(Part III); p. III-353-III-356
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Berger-By, G.; Achard, J.; Beaumont, B.; Bibet, P.; Dutheil, S.; Goniche, M.; Lombard, G.; Millon, L.; Mollard, P.; Vulliez, K., E-mail: bergerby@drfc.cad.cea.fr2001
AbstractAbstract
[en] The tokamak Tore Supra (TS) has been operated since 1988 in Cadarache Centre. With the Composants Internes et Limiteur project, it will be the only machine to be able to exploit the Advanced Tokamak Regimes in steady state operation with three heating systems ICRH, LH, ECRH. The injected RF power in the Torus is a very important parameter of the total energy balance of TS, for this reason we need the best possible knowledge of these powers. The analysis and the explanation of the different RF techniques at low power which have been used in TS on the three RF systems will be described. Principles of the different measurement systems are given. The calibration methods of these systems are discussed and the present status of the calibration uncertainties of the RF measurements is analysed. Finally, when the generators are connected to a dummy load, RF measurements are compared with the calorimetric power measurements. This study allows preparation of improvements of these systems which will be used in these next steps: Composants pour l'Injection de Matiere et d'Energie Stationnaire project (B. Beaumont, Tore Supra steady state power and particles injection: the CIMES project, in: Proceedings of the 21st SOFT, Madrid, 2000)
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S0920379601003866; Copyright (c) 2001 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
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