G P Maddison A E Hubbard J W Hughes J A Snipes B Labombard I M Nunes M N A Beurskens S K Erents M A H Kempenaars B Alper S D Pinches M Valovic R Pasqualotto A Alfier E Giovannozzi JET EFDA Contributors
Experiments on the Alcator C-Mod and JET tokamaks with identical values of nondimensional variables at the pedestal top are expected to have the same local plasma transport for a ratio > 4 in absolute size and thus can help to clarify other effects in pedestal formation. At the high and low fields (7.9 T, 1.4 T respectively) involved, natural-densi…
PublishedS. Dormido-Canto G. Farias J. Vega R. Dormido J. Sánchez N. Duro H. Vargas A. Murari JET-EFDA Contributors
The last flux surface can be used to identify the plasma configuration of discharges. For automated recognition of JET configurations, a learning system based on support vector machines has been developed. Each configuration is described by 12 geometrical parameters. A multiclass system has been developed by means of the one-versus-the-rest approac…
PublishedL. Meneses L. Cupido A. Sirinelli M. E. Manso JET-EFDA Contributors
We present the main design options and implementation of an X -mode reflectometer developed and successfully installed at JET using an innovative approach. It aims to prove the viability of measuring density profiles with high spatial and temporal resolution using broadband reflectometry operating in long and complex transmission lines. It probes t…
PublishedL. Cupido A. Cardinali R. Igreja F. Serra M. E. Manso A. Murari JET-EFDA Contributors
The measurement of the fuel mixture remains a very difficult task in thermonuclear plasmas, where the hydrogen isotopes are fully stripped and do not emit line radiation. On the other hand, direct determination of the ion species mix will be essential in the reactor to keep the mixture close to 50/50 and maximize the fusion output. In this paper, t…
PublishedMarco Ariola Gianmaria De Tommasi Didier Mazon Didier Moreau Fabio Piccolo Alfredo Pironti Filippo Sartori Luca Zabeo JET-EFDA Contributors
Advance tokamak scenarios are gaining more and more importance in operating tokamaks. These scenarios pose challenging control problems, since they require the simultaneous achievement of ambitious plasma parameters. The inherent coupling among the various variables calls for an integrated approach for the design of the controllers. This paper desc…
PublishedOliver Ford J. Svensson A. Boboc D. C. Mcdonald JET-EFDA Contributors
An analytical Bayesian inversion of the JET interferometry line integrated densities into density profiles and associated uncertainty information, is demonstrated. These are used, with a detailed model of plasma polarimetry, to predict the rotation and ellipticity for the JET polarimeter. This includes the lateral channels, for over 45,000 time poi…
PublishedYueqiang Liu M. S. Chu A. M. Garofalo R. J. La Haye Y. Gribov M. Gryaznevich T. C. Hender D. F. Howell P. De Vries M. Okabayashi S. D. Pinches H. Reimerdes EFDA-JET Contributors
Active control of the resistive wall mode RWM for DIII-D [Luxon and Davis, Fusion Technol. 8 , 441 (1985)] plasmas is studied using the MARS-F code [Y. Q. Liu, and et al. , Phys. Plasmas 7 , 3681 (2000)]. Control optimization shows that the mode can be stabilized up to the ideal wall beta limit, using the internal control coils I-coils and poloidal…
PublishedG. J. Kramer R. Nazikian B. Alper M. De Baar H. L. Berk G.-Y. Fu N. N. Gorelenkov G. Mckee S. D. Pinches T. L. Rhodes S. E. Sharapov W. M. Solomon M. A. Van Zeeland JET EFDA Contributors
Reversed shear Alfvén eigenmodes RSAE that were observed in the Joint European Torus (JET) [P. H. Rebut and B. E. Keen, Fusion Technol. 11 , 13 (1987)] and DIII-D [J. L. Luxon, Nucl. Fusion 42 , 614 (2002)] are studied with the ideal magnetohydrodynamic code NOVA-K C. [Z. Cheng, Phys. Rep. 211 , 1 (1992)]. It was found that the frequency behavior …
PublishedM. F. F. Nave H. R. Koslowski S. Coda J. Graves M. Brix R. Buttery C. Challis C. Giroud M. Stamp P. De Vries Jet-Feda Contributors
During a recent reversed toroidal field (B T) campaign at the Joint European Torus (JET), experiments were performed to investigate the effect on sawteeth of neutral beam injection (NBI)-driven toroidal plasma rotation counter to the direction of the toroidal plasma current and B T . A power scan at constant density has permitted analytical continu…
PublishedP. H. Titus J. Snipes A. F. Fasoli D.Testa B.Walton JET-EFDA Contributors
In this paper the mechanical design of the new active MHD antennas for JET is described and the structural/mechanical analysis for the antennas is presented. These new antennas replace the existing n = 1 or 2 saddle coils with a set of eight smaller antennas designed to excite Toroidal Alfvén Eigenmodes (TAE's) with high toroidal mode number (n ~ …
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