The TORE SUPRA Cryogenic System Behaviour During Long Plasma Discharges with a High Injected Energy
Abstract
After the CIEL project completion including the upgrade of the plasma facing components and the water cooling system, the superconducting Tore Supra Tokamak achieved a world record of injected energy (1.1 GJ), during long duration (6 min) plasma discharges, which was enabled by the upgrade of the transfer system capacities, but also by the steady state toroidal field. The Tore Supra cryogenic refrigerator enables the toroidal field coils to be operated at nominal current along the full daily plasma operation shift. It has capacities of 300 W at 1.8 K, 750 W at 4.5 K and 30 kW at 80 K and was operated with a high reliability for more than 16 years. After a brief recall on the cryogenic refrigeration of the toroidal superconducting magnet, the distribution of the heat loads at the various levels of temperature (in standby mode 150W at 1.8 K and 200W at 4.5 K) is presented. The inventory of the calculated static and variable heat loads deposited within each part of toroidal field coils and thermal shields, is given with the factors of dependence. This analysis identifies and quantifies the major magnetic disturbances like a disruption (about 12 kJ onto the coils and 300more »
- Authors:
- Departement de Recherches sur la Fusion Controlee, Association, Euratom-CEA, CEA/Cadarache, F-13108 Saint Paul-lez-Durance (France)
- Publication Date:
- OSTI Identifier:
- 20800203
- Resource Type:
- Journal Article
- Resource Relation:
- Journal Name: AIP Conference Proceedings; Journal Volume: 823; Journal Issue: 1; Conference: Cryogenic engineering conference, Keystone, CO (United States), 29 Aug - 2 Sep 2005; Other Information: DOI: 10.1063/1.2202563; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; COOLING SYSTEMS; CRYOGENICS; DISTURBANCES; ELECTRIC CURRENTS; ELECTRIC DISCHARGES; FIRST WALL; HEATING LOAD; HELIUM; ITER TOKAMAK; OPERATION; PLASMA; PUMPING; REFRIGERATION; REFRIGERATORS; STANDBY MODE; STEADY-STATE CONDITIONS; SUPERCONDUCTING COILS; SUPERCONDUCTING MAGNETS; THERMAL SHIELDS; TORE SUPRA TOKAMAK
Citation Formats
Henry, D., Hertout, P., Journeaux, J. Y., Duchateau, J. L., and Reynaud, P.. The TORE SUPRA Cryogenic System Behaviour During Long Plasma Discharges with a High Injected Energy. United States: N. p., 2006.
Web. doi:10.1063/1.2202563.
Henry, D., Hertout, P., Journeaux, J. Y., Duchateau, J. L., & Reynaud, P.. The TORE SUPRA Cryogenic System Behaviour During Long Plasma Discharges with a High Injected Energy. United States. doi:10.1063/1.2202563.
Henry, D., Hertout, P., Journeaux, J. Y., Duchateau, J. L., and Reynaud, P.. Thu .
"The TORE SUPRA Cryogenic System Behaviour During Long Plasma Discharges with a High Injected Energy". United States.
doi:10.1063/1.2202563.
@article{osti_20800203,
title = {The TORE SUPRA Cryogenic System Behaviour During Long Plasma Discharges with a High Injected Energy},
author = {Henry, D. and Hertout, P. and Journeaux, J. Y. and Duchateau, J. L. and Reynaud, P.},
abstractNote = {After the CIEL project completion including the upgrade of the plasma facing components and the water cooling system, the superconducting Tore Supra Tokamak achieved a world record of injected energy (1.1 GJ), during long duration (6 min) plasma discharges, which was enabled by the upgrade of the transfer system capacities, but also by the steady state toroidal field. The Tore Supra cryogenic refrigerator enables the toroidal field coils to be operated at nominal current along the full daily plasma operation shift. It has capacities of 300 W at 1.8 K, 750 W at 4.5 K and 30 kW at 80 K and was operated with a high reliability for more than 16 years. After a brief recall on the cryogenic refrigeration of the toroidal superconducting magnet, the distribution of the heat loads at the various levels of temperature (in standby mode 150W at 1.8 K and 200W at 4.5 K) is presented. The inventory of the calculated static and variable heat loads deposited within each part of toroidal field coils and thermal shields, is given with the factors of dependence. This analysis identifies and quantifies the major magnetic disturbances like a disruption (about 12 kJ onto the coils and 300 kJ onto the thick casings) which generate additional heat loads for the refrigerator.The measurements associated with the He II saturated bath pumping system, and the supercritical helium loop cooling the thick casings, allow us to verify thereafter the behaviour of the cryo-refrigerator during the long duration discharges, and the compliance with the theoretical model.The conclusions bring results also applicable to the cyoplant of future plant like ITER which will operate with long duration discharges.},
doi = {10.1063/1.2202563},
journal = {AIP Conference Proceedings},
number = 1,
volume = 823,
place = {United States},
year = {Thu Apr 27 00:00:00 EDT 2006},
month = {Thu Apr 27 00:00:00 EDT 2006}
}
-
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. 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 regorous 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 Toremore »
-
Heat Flux Calculation and Problem of Flaking of Boron Carbide Coatings on the Faraday Screen of the ICRH Antennas During Tore Supra High Power, Long Pulse Operation
Reliable and repetitive high power and long pulse tokamak operation is strongly dependant of the ability to secure the Plasma Facing Components (PFCs). In Tore Supra, a network of 7 infrared (IR) video cameras is routinely used to prevent PFCs overheating and damage in selected regions. Real time feedback control and offline analysis are essential for basic protection and understanding of abnormal thermal events. One important limitation detected by the IR real time feed-back loop during high power RF operation (injected power of 9.5 MW over 26 s and 12 MW over 10 s have been achieved respectively in 2006more » -
Spectral broadening measurement of the lower hybrid waves during long pulse operation in Tore Supra
On many tokamaks (C-Mod, EAST, FTU, JET, HT-7, TS), a decrease in current drive efficiency of the Lower Hybrid (LH) waves is observed in high electron density plasmas. The cause of this behaviour is believed to be: Parametric Instabilities (PI) and Scattering from Density Fluctuations (SDF). For the ITER LH system, our knowledge must be improved to avoid such effects and to maintain the LH current drive efficiency at high density. The ITPA IOS group coordinates this effort [1] and all experimental data are essential to validate the numerical codes in progress. Usually the broadening of the LH wave frequencymore » -
Advances in long pulse operation at high radio frequency power in Tore Supra
The lower hybrid current drive (LHCD) system of Tore Supra has been upgraded for long pulse operation at higher power (7–8 MW). The two launchers have coupled on plasma 3.8 MW and 2.7 MW separately. This new power capability allows extending the operational domain of Tore Supra for long pulses at higher current and density. 38 long (20 s –155 s) discharges with very low loop voltage (V{sub L} = 30-60 mV) were performed with combined LHCD (5-5.7 MW) and ICRH (1–3 MW) powers, with up to 1 GJ of injected energy. Higher LHCD efficiency, with respect to the previous long discharges, is reported. MHD stability of these discharges ismore » -
Validation of CW High Power Sources and RF Components for the Tore Supra LHCD System
The upgraded 3.7 GHz Lower Hybrid Current Drive (LHCD) system for the Tore Supra (TS) tokamak is in the process of installation. When complete, it will permit long pulse injection (1000s) at coupled power level up to 6, 5 MW. Steady state operation of high power RF sources and components is challenging and requires careful validation before the system can be commissioned on the tokamak.Results on the validation of CW klystrons, improvements on the RF components forming part of the power generation circuit and the development of an RF water load to sustain CW pulses under 700 kW RF powermore »