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Low MHD activity using resonant helical field and limiter biasing in IR-T1 tokamak

Published online by Cambridge University Press:  03 May 2013

M. LAFOUTI ,
M. GHORANNEVISS ,
S. MESHKANI  and
A. SALAR ELAHI
M. LAFOUTI
Affiliation:
Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran, Iran (salari_phy@yahoo.com)
M. GHORANNEVISS
Affiliation:
Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran, Iran (salari_phy@yahoo.com)
S. MESHKANI
Affiliation:
Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran, Iran (salari_phy@yahoo.com)
A. SALAR ELAHI
Affiliation:
Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran, Iran (salari_phy@yahoo.com)
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Abstract

In this paper, the effect of resonant helical magnetic field (RHF) and cold biased local limiter on plasma current, loop voltage, confinement time energy, poloidal beta, line emission intensity Hα, and magnetohydrodynamic (MHD) behavior based on Mirnov oscillations in the IR-T1 tokamak has been investigated. The experiments have been done in different regimes as cold biased local limiter, magnetic perturbation application, and both of these. At first the effect of the positive and negative bias voltage on plasma parameters and magnetic fluctuations detected by Mirnov coils has been investigated. Also, the effects of RHF on plasma parameters have been investigated in the edge region. Then the effects of applied biasing and RHF at the same time are analyzed. The bias voltage has been restricted to (−320 ≤ Vbias ≤ +320) and it has been applied with the limiter biasing that is fixed at r = 11.25 cm. These parameters have been measured using a diamagnetic loop, spectrometer, which is a visible light spectrometer for H-alpha, and Mirnov coils. The time-resolved frequency component analysis has been performed using short-time Fourier transforms. Fourier-based techniques and auto-correlation have been employed to analyze the frequency of MHD fluctuations. The results show that applied radial electric field at the plasma edge could control electromagnetic instabilities in the tokamak. In the positive biased regime, the amplitude of low-frequency Mirnov oscillations (<30 kHz) decreases after the application of biasing. Confinement time increases and line emission intensity decreases in all situations. The results are reversed when negative biasing has been applied. When RHF and biasing are applied to the plasma at the same time, the plasma parameters do not change any more compared to corresponding discharges with only RHF (L = 3). In other words, the amplitude of MHD activity can be totally controlled when a convenient biasing is applied to the limiter in the phases of current flat-top.

Type
Papers
Information
Journal of Plasma Physics , Volume 79 , Issue 5 , October 2013 , pp. 765 - 770
Copyright
Copyright © Cambridge University Press 2013 

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References

Burrell, K. H. 1999 Phys. Plasmas 6, 4418.CrossRefGoogle Scholar
Cabral, J. A. C., Varandas, C. A. F., Alonso, M. P., Belo, P., Canário, R., Fernandes, H., Gomes, R., Malaquias, A., Malinov, P., Serra, F., Silva, F. and Soares, A. 1998 Plasma Phys. Control. Fusion 40, 1001–1009.CrossRefGoogle Scholar
Endler, M. 1995 Nucl. Fusion 35, 1307.CrossRefGoogle Scholar
Endler, M. 1999 Plasma Phys. Control. Fusion 41, 1431.CrossRefGoogle Scholar
Fiksel, G., Prager, S. C., Pribyl, P., Taylor, R. J. and Tynan, G. R. 1995 Phys. Rev. Lett. 75, 3866.CrossRefGoogle Scholar
Hutchinson, I. H. 1987 Principles of Plasma Diagnostics. Cambridge, UK: Cambridge University Press, pp. 10–33.Google Scholar
Karger, F., Wobig, H., Corti, S., Gernhardt, J., Klüber, O., Lisitano, G., McCormick, K., Meisel, D. and Sesnic, S. 1975 Plasma Physics and Controlled Nuclear Fusion Energy Research 1974. IAEA 5th International Conference Proceedings, Vol. 1. Vienna, Austria: International Atomic Energy Agency, 207 pp.Google Scholar
Khorshid, P. 2001 Chin. Phys. Lett. 18, 393.Google Scholar
Mikhailovskii, A. B. and Sharapov, S. E. 2000 Plasma Phys. Control. Fusion 42, 57–70.CrossRefGoogle Scholar
Nedospasov, A. V. 1993 Phys. Fluids 5, 3191.CrossRefGoogle Scholar
Phillips, P. E. 1987 J. Nucl. Mater. 145–147, 807.CrossRefGoogle Scholar
Ritz, C. H. 1988 Rev. Sci. Instrum. 59, 1739–1744.CrossRefGoogle Scholar
Salar Elahi, A. and Ghoranneviss, M. 2010 J. Fusion Energy, 29, 36–40.CrossRefGoogle Scholar
Serianni, G. 2001 Plasma Phys. Control. Fusion 43, 919.CrossRefGoogle Scholar
Tramontin, L., Garzotti, L., Antoni, V., Carraro, L., Desideri, D., Innocente, P., Martines, E., Serianni, G., Spolaore, M. and Vianello, N. 2002 Plasma Phys. Control. Fusion 44, 195.CrossRefGoogle Scholar
Van Oost, G., Adámek, J., Antoni, V., Balan, P., Boedo, J. A., Devynck, P., Ďuran, I., Eliseev, L., Gunn, J. P., Hron, M., Ionita, C., Jachmich, S., Kirnev, G. S., Martines, E., Melnikov, A., Schrittwieser, R., Silva, C., Stöckel, J., Tendler, M., Varandas, C., Van Schoor, M., Vershkov, V. and Weynants, R. R.Van, M. 2003 Plasma Phys. Control. Fusion 45, 621.CrossRefGoogle Scholar
Wang, G. D. 1998 Chin. Phys. Lett. 15, 510.CrossRefGoogle Scholar