论文信息 - Demonstration of effective control of fast-ion-stabilized sawteeth by electron-cyclotron current drive. - 字舞流文

Demonstration of effective control of fast-ion-stabilized sawteeth by electron-cyclotron current drive.

In a tokamak plasma, sawtooth oscillations in the central temperature, caused by a magnetohydrodynamic instability, can be partially stabilized by fast ions. The resulting less frequent sawtooth crashes can trigger unwanted magnetohydrodynamic activity. This Letter reports on experiments showing that modest electron-cyclotron current drive power, with the deposition positioned by feedback control of the injection angle, can reliably shorten the sawtooth period in the presence of ions with energies >or=0.5 MeV. Certain surprising elements of the results are evaluated qualitatively in terms of existing theory.

F Turco | F. Turco | G. Giruzzi | M. Lennholm | F. Bouquey | C. Darbos | E. Traisnel | F. Rimini | R. Dumont | J. Ségui | P. Moreau | L. Eriksson | R. Magne | D. Molina | R Dumont | L-G Eriksson | M Lennholm | F Rimini | G Giruzzi | F Bouquey | C Darbos | R Magne | M Jung | R Lambert | D Molina | P Moreau | J-L Segui | S Song | E Traisnel | R. Lambert | M. Jung | S. Song

[1] Olivier Sauter,et al. Effects of localized electron heating and current drive on the sawtooth period , 2003 .

[2] J. Manickam,et al. Chapter 3: MHD stability, operational limits and disruptions , 2007 .

[3] H. Zohm,et al. Neoclassical Tearing Modes , 2000 .

[4] D. A. Humphreys,et al. CONTROL OF NEOCLASSICAL TEARING MODES IN DIII-D , 2001 .

[5] Bhatnagar,et al. Stabilization of sawteeth with additional heating in the JET tokamak. , 1988, Physical review letters.

[6] R J Buttery,et al. Destabilization of fast-ion-induced long sawteeth by localized current drive in the JET tokamak. , 2004, Physical review letters.

[7] Gilles Berger-By,et al. The ECRH/ECCD system on Tore Supra, a major step towards continuous operation , 2003 .

[8] M. Rosenbluth,et al. Model for the sawtooth period and amplitude , 1996 .

[9] E. Joffrin,et al. Thermal and non-thermal particle interaction with the LHCD launchers in Tore Supra , 2007 .

[10] D. McDonald,et al. A new type of MHD activity in JET ICRF-only discharges with high fast-ion energy contents , 2000 .

[11] O. Sauter,et al. Control of neoclassical tearing modes by sawtooth control. , 2002, Physical review letters.

[12] L. L. Lao,et al. Beta limits in long-pulse tokamak discharges , 1997 .

[13] M. Mayoral,et al. Chapter 9: Physics Studies with the Additional Heating Systems in JET , 2008 .

[14] E. D. Fredrickson,et al. Ion cyclotron range of frequencies stabilization of sawteeth on Tokamak Fusion Test Reactor , 1992 .

[15] L. Eriksson,et al. Sawtooth-control mechanism using toroidally propagating ion-cyclotron-resonance waves in tokamaks. , 2009, Physical review letters.

[16] Ion cyclotron range of frequency mode conversion physics in Alcator C-Mod: Experimental measurements and modelinga) , 2005 .

[17] Olivier Sauter,et al. Control of sawteeth and triggering of NTMs with ion cyclotron resonance frequency waves in JET , 2002 .

[18] R. L. Meyer,et al. Improving current generation in a tokamak by electron cyclotron waves , 1985 .

[19] Francesco Porcelli,et al. Local magnetic shear control in a tokamak via fast wave minority ion current drive : theory and experiments in jet , 1994 .

[20] H. Zohm,et al. Sawtooth control experiments on ASDEX Upgrade , 2005 .