Hostname: page-component-848d4c4894-hfldf Total loading time: 0 Render date: 2024-06-07T03:00:04.963Z Has data issue: false hasContentIssue false

Exploration of spontaneous vortex formation and intermittent behavior in ECR plasmas: The HYPER-I experiments

Published online by Cambridge University Press:  08 December 2014

S. Yoshimura*
Affiliation:
National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
K. Terasaka
Affiliation:
Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga 816-8580, Japan
E. Tanaka
Affiliation:
Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga 816-8580, Japan
M. Aramaki
Affiliation:
College of Industrial Technology, Nihon University, Narashino 275-8575, Japan
A. Okamoto
Affiliation:
Department of Quantum Science and Energy Engineering, Tohoku University, Sendai 980-8579, Japan
K. Nagaoka
Affiliation:
National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
M. Y. Tanaka
Affiliation:
Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga 816-8580, Japan
*
Email address for correspondence: yshinji@nifs.ac.jp

Abstract

HYPER-I (High Density Plasma Experiment-I) is a linear device that combines a wide operation range of plasma production with flexible diagnostics. The plasmas are produced by the electron cyclotron resonance (ECR) heating with parallel injection of right-handed circularly polarized microwaves of 2.45 GHz from the high-field side. The maximum attainable electron density is more than two orders of magnitude higher than the cutoff density of ordinary waves. Spontaneous formation of a variety of large-scale flow structures, or vortices, has been observed in the HYPER-I plasmas. Flow-velocity field measurements using directional Langmuir probes (DLPs) and laser-induced fluorescence (LIF) method have clarified the physical processes behind such vortex formations. Recently, a new intermittent behavior of local electron temperature has also been observed. Statistical analysis of the floating potential changes has revealed that the phenomenon is characterized by a stationary Poisson process.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2014 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Allen, L., Babiker, M. and Power, W. L. 1994 Azimuthal Doppler shift in light beams with orbital angular momentum. Opt. Commun. 112, 141144.CrossRefGoogle Scholar
Aramaki, M., Ogiwara, K., Etoh, S., Yoshimura, S. and Tanaka, M. Y. 2009 High resolution laser induced fluorescence doppler velocimetry utilizing saturated absorption spectroscopy. Rev. Sci. Instrum. 80, 053 505.CrossRefGoogle ScholarPubMed
Aramaki, M., Ogiwara, K., Etoh, S., Yoshimura, S. and Tanaka, M. Y. 2010 Measurement of neutral flow velocity in an ECR plasma using tunable diode laser LIF spectroscopy combined with saturated absorption spectroscopy. J. Phys.: Conf. Ser. 227, 012 008.Google Scholar
Aschwanden, M. 2011 Self-Organized Criticality in Astrophysics: The Statistics of Nonlinear Processes in the Universe, Berlin: Springer.CrossRefGoogle Scholar
Carter, T. A. 2006 Intermittent turbulence and turbulent structures in a linear magnetized plasma. Phys. Plasmas 13, 010 701.Google Scholar
Chen, F. F. 1984 Introduction to Plasma Physics and Controlled Fusion, Plenum: New York.CrossRefGoogle Scholar
D'Ippolito, D. A., Myra, J. R. and Zweben, S. J. 2011 Convective transport by intermittent blob-filaments: comparison of theory and experiment. Phys. Plasmas 18, 060 501.CrossRefGoogle Scholar
Horton, W. 1999 Drift waves and transport. Rev. Mod. Phys. 71, 735778.Google Scholar
Kono, M. and Tanaka, M. Y. 2000a Spiral structures in magnetized rotating plasmas. Phys. Rev. Lett. 84, 43694372.CrossRefGoogle ScholarPubMed
Kono, M. and Tanaka, M. Y. 2000b Theory for spiral structure formation in rotating plasma. Phys. Scr. T84, 4751.Google Scholar
Lieberman, M. A. and Lichtenberg, A. J. 2005 Principles of Plasma Discharges and Material Processing, Hoboken: Wiley.Google Scholar
Nagaoka, K., Okamoto, A., Yoshimura, S., Kono, M. and Tanaka, M. Y. 2002 Spontaneous formation of a plasma hole in a rotating magnetized plasma: a giant Burgers vortex in a compressible fluid. Phys. Rev. Lett. 89, 075 001.Google Scholar
Nagaoka, K., Okamoto, A., Yoshimura, S. and Tanaka, M. Y. 2001 Plasma flow measurement using directional Langmuir probe under weakly ion-magnetized conditions. J. Phys. Soc. Japan. 70, 131137.CrossRefGoogle Scholar
Okamoto, A., Hara, K., Nagaoka, K., Yoshimura, S., Vranjěs, J., Kono, M. and Tanaka, M. Y. 2003 Experimental observation of a tripolar vortex in a plasma. Phys. Plasmas 10, 22112216.CrossRefGoogle Scholar
Tanaka, M., Nishimoto, R., Higashi, S., Harada, N., Ohi, T., Komori, A. and Kawai, Y. 1991 Overdense plasma production using electron cyclotron waves. J. Phys. Soc. Japan. 60, 16001607.CrossRefGoogle Scholar
Tanaka, M. Y., Bacal, M., Sasao, M. and Kuroda, T. 1998 High-density plasma production for neutralizing negative ion beam. Rev. Sci. Instrum. 69, 980982.CrossRefGoogle Scholar
Tanaka, M. Y., Nagaoka, K., Okamoto, A., Yoshimura, S. and Kono, M. 2004 Formation of visco-disipative vortex and quasi-neutrality breaking in a magnetized plasma. Phys. Scr. T107, 4953.Google Scholar
Tanaka, M. Y., Nagaoka, K., Okamoto, A., Yoshimura, S. and Kono, M. 2005 Plasma hole. IEEE Trans. Plasma Sci. 33, 454455.Google Scholar
Terasaka, K., Yoshimura, S., Katahira, T., Ogiwara, K., Aramaki, M. and Tanaka, M. Y. 2010 Self-calibrated measurement of ion flow using a fine multihole directional Langmuir probe. Japan. J. Appl. Phys. 49, 036 101.Google Scholar
Vrangěs, J., Kono, M., Petrovic, D., Poedts, S., Okamoto, A., Yoshimura, S. and Tanaka, M. Y. 2006 The effects of inelastic collisions on waves in partially ionized plasma. Plasma Source Sci. Technol. 15, S1S7.CrossRefGoogle Scholar
Vrangěs, J., Okamoto, A., Yoshimura, S., Poedts, S., Kono, M., Kono, M. and Tanaka, M. Y. 2002 Analytical description of a neutral-induced tripole vortex in a plasma. Phys. Rev. Lett. 89, 265 002.CrossRefGoogle Scholar
Wheatland, M. S. and Litvinenko, Y. E. 2002 Understanding solar flare waiting-time distributions. Sol. Phys. 211, 255274.CrossRefGoogle Scholar
Windisch, T., Grulke, O., Naulin, V. and Klinger, T. 2011 Intermittent transport events in a cylindrical plasma device: experiment and simulation. Plasma Phys. Control. Fusion 53, 085 001.Google Scholar
Yoshimura, S., Okamoto, A. and Tanaka, M. Y. 2004 Observation of plasma hole in an ECR Ar plasma. J. Plasma Fusion Res. Ser. 6, 610613.Google Scholar
Yoshimura, S., Okamoto, A. and Tanaka, M. Y. 2009 Measurement of ion flow velocity field associated with plasma hole using laser induced fluorescence spectroscopy. J. Plasma Fusion Res. Ser. 8, 1114.Google Scholar
Yoshimura, S., Terasaka, K., Tanaka, E., Aramaki, M. and Tanaka, M. Y. 2014 Probability density functions of floating potential fluctuations due to local electron flux intermittency in a linear ECR plasma. JPS Conf. Proc. 1, 015 030.Google Scholar