Abstract
In net-free current plasmas that are confined in the L-2M stellarator, an electromagnetic mode having thresholds in the plasma density and pressure was observed. The characteristic frequency of the unstable mode was 70–90 kHz, and the direction of its rotation pointed toward the direction of ion diamagnetic drift. The instability was observed at n(0) > 1.5 × 1013 cm-3 and 〈β〉 > 0.14%, where n(0) is the plasma density averaged over the central chord and 〈β〉 is volume-averaged ratio of the gas kinetic pressure to the magnetic pressure. This phenomenon cannot be described within the theory of resistive interchange modes. Possible reasons for the occurrence of the observed electromagnetic mode are discussed using analytical estimations.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
M. I. Mikhailov, S. V. Shchepetov, K. Nührenberg, and J. Nührenberg, Plasma Phys. Rep. 41, 1016 (2015).
S. P. Hirshman, W. I. Rij, and P. Merkel, Comput. Phys. Commun. 43, 143 (1986).
C. Nuehrenberg, in Proceedings of the 30th EPS Conference on Controlled Fusion and Plasma Physics, St. Petersburg, 2003, ECA 27A, P-1.16 (2003).
D. K. Akulina, G. M. Batanov, M. S. Berezhetskii, G. A. Gladkov, S. E. Grebenshchikov, I. S. Danilkin, L. M. Kovrizhnykh, L. V. Kolik, A. B. Kuznetsov, N. F. Larionova, K. M. Likin, N. I. Malykh, A. I. Meshcheryakov, A. E. Petrov, K. A. Sarksyan, et al., JETP Lett. 69, 441 (1999).
S. V. Shchepetov, Plasma Phys. Controlled Fusion 58, 114002 (2016).
S. V. Shchepetov and D. G. Vasilkov, Plasma Phys. Rep. 43, 720 (2017).
F. Wagner, S. Bäumel, J. Baldzuhn, N. Basse, R. Brakel, R. Burhenn, A. Dinklage, D. Dorst, H. Ehmler, H. Endler, V. Erckmann, Y. Feng, F. Gadelmeier, J. Geiger, L. Giannone, et al., Phys. Plasmas 12, 072509 (2005).
A. Komori, H. Yamada, S. Sakikabara, O. Kaneko, K. Kawahata, T. Mutoh, N. Ohyabu, S. Imagawa, S. Ida, Y. Nagayama, T. Shimozuma, K. Y. Watanabe, T. Mito, M. Kobayashi, S. Nagaoka, et al., Nucl. Fusion 49, 104015 (2009).
T. Hayashi, T. Sato, and A. Takei, Phys. Fluids B 2, 329 (1990).
J. A. Jimenez, E. de la Luna, I. Garcia-Cortes, and S. V. Shchepetov, Plasma Phys. Controlled Fusion 48, 515 (2006).
A. B. Mikhailovskii and S. E. Sharapov, Plasma Phys. Rep. 25, 803 (1999).
R. J. Hastie, J. J. Ramos, and F. Porcelli, Phys. Plasmas 10, 4405 (2003).
S. V. Shchepetov, Yu. V. Kholnov, O. I. Fedyanin, A. B. Kuznetsov, D. G. Vasilkov, D. K. Akulina, G. M. Batanov, G. A. Gladkov, S. E. Grebenshchikov, and A. I. Meshcheryakov, Plasma Phys. Controlled Fusion 50, 045001 (2008).
N. K. Kharchev, G. M. Batanov, M. S. Berezhetskii, V. D. Borzosekov, O. I. Fedyanin, S. E. Grebenshchikov, I. A. Grishina, Yu. V. Kholnov, L. V. Kolik, E. M. Konchekov, L. M. Kovrizhnykh, N. F. Larionova, D. V. Malakhov, A. I. Meshcheryakov, A. E. Petrov, et al., Plasma Fusion Res. 6, 2402142 (2011).
S. V. Shchepetov, J. A. Jimenez, and A. B. Kuznetsov, Plasma Phys. Controlled Fusion 43, 417 (2001).
S. V. Shchepetov, Yu. V. Kholnov, and D. G. Vasilkov, Plasma Phys. Rep. 39, 130 (2013).
D. G. Vasilkov, Yu. V. Kholnov, and S. V. Shchepetov, Plasma Phys. Rep. 39, 615 (2013).
S. I. Braginskii, in Reviews of Plasma Physics, Ed. by M. A. Leontovich (Consultants Bureau, New York, 1965), Vol. 1, p. 205.
Author information
Authors and Affiliations
Corresponding author
Additional information
Original Russian Text © S.V. Shchepetov, D.G. Vasilkov, Yu.V. Kholnov, 2018, published in Fizika Plazmy, 2018, Vol. 44, No. 6, pp. 469–474.
Rights and permissions
About this article
Cite this article
Shchepetov, S.V., Vasilkov, D.G. & Kholnov, Y.V. Experimental Observation of an Unstable Mode in Theoretically Ideal MHD Stable Plasmas Confined in the L-2M Stellarator. Plasma Phys. Rep. 44, 539–543 (2018). https://doi.org/10.1134/S1063780X18060090
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S1063780X18060090