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Effect of toroidal Alfvén eigenmodes on fast particle confinement in the spherical tokamak Globus-M

Part of: Focus on Fusion PLA Tribute to V D Shafranov: 1929-2014

Published online by Cambridge University Press:  08 October 2015

Yu. V. Petrov ,
N. N. Bakharev ,
V. K. Gusev ,
V. B. Minaev ,
V. A. Kornev ,
G. S. Kurskiev ,
M. I. Patrov ,
N. V. Sakharov ,
S. Yu. Tolstyakov  and
P. B. Shchegolev
Yu. V. Petrov*
Affiliation:
Ioffe Institute, St Petersburg, 194021, Russia
N. N. Bakharev
Affiliation:
Ioffe Institute, St Petersburg, 194021, Russia
V. K. Gusev
Affiliation:
Ioffe Institute, St Petersburg, 194021, Russia
V. B. Minaev
Affiliation:
Ioffe Institute, St Petersburg, 194021, Russia
V. A. Kornev
Affiliation:
Ioffe Institute, St Petersburg, 194021, Russia
G. S. Kurskiev
Affiliation:
Ioffe Institute, St Petersburg, 194021, Russia
M. I. Patrov
Affiliation:
Ioffe Institute, St Petersburg, 194021, Russia
N. V. Sakharov
Affiliation:
Ioffe Institute, St Petersburg, 194021, Russia
S. Yu. Tolstyakov
Affiliation:
Ioffe Institute, St Petersburg, 194021, Russia
P. B. Shchegolev
Affiliation:
Ioffe Institute, St Petersburg, 194021, Russia
*
†Email address for correspondence: yu.petrov@mail.ioffe.ru
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Abstract

In experiments with neutral beam injection at the early stage of a Globus-M discharge, instabilities were observed that were excited by fast ions in the frequency range of 50–200 kHz, which were identified as toroidal Alfvén eigenmodes (TAE) (Petrov et al., Plasma Phys. Rep., vol. 37, 2011, pp. 1001–1005). In contradiction with the NSTX and MAST tokamaks, a regime of TAE generation was realized with strongly developed single modes. Magnetic measurements with fast Mirnov probes have shown that most of the modes have toroidal number $n=1$. The influence of the modes on the fast particle confinement was recorded by means of a tangentially directed neutral particle analyser (NPA) and neutron detector. Hydrogen and deuterium were used as target plasma and injected beam for study of the isotopic effect. At deuterium injection into the deuterium plasma, TAE led to the neutron rate dropping by 25 %, whereas NPA fluxes of high energy dropped by 75 %. At hydrogen injection, the drop in the measured NPA fluxes did not exceed 25 %.

Type
Research Article
Information
Journal of Plasma Physics , Volume 81 , Issue 6 , December 2015 , 515810601
Copyright
© Cambridge University Press 2015 

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References

Berk, H. L., Breizman, B. N. & Ye, H. 1992 Finite orbit energetic particle linear response to toroidal Alfvén eigenmodes. Phys. Lett. A 162, 475.Google Scholar
Cheng, C. Z. & Chance, M. S. 1986 Low- $n$ shear Alfvén spectra in axisymmetric toroidal plasmas. Phys. Fluids 11, 3695.Google Scholar
Darrow, D. S., Fredrickson, E. D., Gorelenkov, N. N., Roquemore, A. L. & Shinohara, K. 2008 MHD induced neutral beam ion loss from NSTX plasmas. Nucl. Fusion 48, 084004.Google Scholar
Duong, H. H., Heidbrink, W. W., Strait, E. J., Petrie, T. W., Lee, R., Moyer, R. A. & Watkins, J. G. 1993 Loss of energetic beam ions during TAE instabilities. Nucl. Fusion 33, 749.Google Scholar
Fredrickson, E. D., Cheng, C. Z., Darrow, D., Fu, G., Gorelenkov, N. N., Kramer, G., Medley, S. S., Menard, J., Roquemore, L., Stutman, D. & White, R. B. 2003 Wave driven fast ion loss in the national spherical torus experiment. Phys. Plasmas 16, 2852–2862.Google Scholar
Fredrickson, E. D. et al. 2009 Modeling fast-ion transport during toroidal Alfvén eigenmode avalanches in National Spherical Torus Experiment. Phys. Plasmas 16, 122505.Google Scholar
Fredrickson, E. D. et al. 2013 Fast-ion energy loss during TAE avalanches in the National Spherical Torus Experiment. Nucl. Fusion 53, 013006.CrossRefGoogle Scholar
García-munõz, M., Fahrbach, H.-U., Günter, S., Igochine, V., Mantsinen, M. J., Maraschek, M., Martin, P., Piovesan, P., Sassenberg, K. & Zohm, H. 2008 Fast-ion losses due to high-frequency MHD perturbations in the ASDEX upgrade tokamak. Phys. Rev. Lett. 100, 055005.Google Scholar
Gryaznevich, M. P. & Sharapov, S. E. 2000 Frequency sweeping Alfvén instabilities driven by super-Alfvénic beams in the spherical tokamak START. Nucl. Fusion 40, 907.CrossRefGoogle Scholar
Gryaznevich, M. P. & Sharapov, S. E. 2004 Beta-dependence of energetic particle-driven instabilities in spherical tokamaks. Plasma Phys. Control. Fusion 46, S15.Google Scholar
Gryaznevich, M. P. & Sharapov, S. E. 2006 Perturbative and non-perturbative modes in START and MAST. Nucl. Fusion 46, S942.CrossRefGoogle Scholar
Gusev, V. K. et al. 1999 Globus-M spherical tokamak. Tech. Phys. 44, 1054–1057.CrossRefGoogle Scholar
Gusev, V. K. et al. 2007 Tech. Phys. 44, 1127–1143.Google Scholar
Gusev, V. K. et al. 2011 Investigation of beam– and wave–plasma interactions in spherical tokamak Globus-M. Nucl. Fusion 51, 103019.Google Scholar
Heidbrink, W. W., Strait, E. J., Doyle, E., Sager, G. & Snider, R. T. 1991 An investigation of beam driven Alfvén instabilities in the DIII-D tokamak. Nucl. Fusion 31, 1635.Google Scholar
Kornev, V. A., Askinazi, L. G., Vildjunas, M. I., Zhubr, N. A., Krikunov, S. V., Lebedev, S. V., Razumenko, D. V., Rozhdestvensky, V. V. & Tukachinsky, A. S. 2013 Confinement of energetic ions in a tokamak plasma at magnetic field in the range of 0.7–1.0 T. Tech. Phys. Lett. 39, 290–293.Google Scholar
Kuteev, B. V., Goncharov, P. R., Sergeev, V. Yu. & khripunov, V. I. 2010 Intense fusion neutron sources. Plasma Phys. Rep. 36, 281–317.Google Scholar
Kuteev, B. V. et al. 2011 Steady-state operation in compact tokamaks with copper coils. Nucl. Fusion 51, 073013.Google Scholar
Minaev, V. et al. 2014 Globus-M2 design peculiarities and status of the tokamak upgrade. In Proceedings of 25th FEC IAEA Conference, St. Petersburg, Russia, 13–18 October 2014. Conference ID: 46091 (CN-221), FIP/P8-25.Google Scholar
Peng, Y. K. et al. 2005 A component test facility based on the spherical tokamak. Plasma Phys. Control. Fusion 47, B263.CrossRefGoogle Scholar
Petrov, Yu. V. 2014 The influence of toroidal Alfvén modes on the confinement of fast particles in the Globus-M spherical tokamak. Tech. Phys. Lett. 40 (12), 1136–1139.Google Scholar
Petrov, Yu. V., Patrov, M. I., Gusev, V. K., Ivanov, A. E., Minaev, V. B., Sakharov, N. V., Tolstyakov, S. Yu. & kurskiev, G. S. 2011 Experimental study of toroidal Alfvén modes in the Globus-M spherical tokamak. Plasma Phys. Rep. 37, 1001–1005.Google Scholar
Podesta, M. et al. 2009 Experimental studies on fast-ion transport by Alfvén wave avalanches on the National Spherical Torus Experiment. Phys. Plasmas 16, 056104.Google Scholar
Podesta, M., Bell, R. E., Bortolon, A., Crocker, N. A., Darrow, D. S. & Diallo, A. 2012 Study of chirping toroidicity-induced Alfvén eigenmodes in the National Spherical Torus Experiment. Nucl. Fusion 52, 094001.Google Scholar
Strait, E. J., Heidbrink, W. W., Turnbull, A. D., Chu, M. S. & Duong, H. H. 1993 Doppler shift of the TAE mode frequency in DIII-D. Nucl. Fusion 33, 1849–1870.CrossRefGoogle Scholar
Strait, E. J., Heidbrink, W. W. & Turnbull, A. D. 1994 Doppler shift of the TAE mode frequency in DIII-D. Plasma Phys. Control. Fusion 36, 1211–1226.Google Scholar
Voss, G. M., Davis, S., Dnestrovskij, A., Kirk, A., Knight, P. J., Loughlin, M., O’brien, M. H., Sychugov, D., Tabasso, A. & Wilson, H. R. 2008 Conceptual design of a component test facility based on the spherical tokamak. Fusion Engng Des. 83, 1648–1653.Google Scholar
Wong, K. L. et al. 1991 Excitation of toroidal Alfvén eigenmodes in TFTR. Phys. Rev. Lett. 66, 1874.Google Scholar