Hostname: page-component-cd9895bd7-gbm5v Total loading time: 0 Render date: 2024-12-27T14:09:18.906Z Has data issue: false hasContentIssue false
  • English
  • Français

Radial characterization of wave magnetic field components during helicon discharge in a small aspect ratio torus

Published online by Cambridge University Press:  15 April 2009

MANASH KUMAR PAUL  and
DHIRAJ BORA
MANASH KUMAR PAUL
Affiliation:
Institute for Plasma Research, Bhat, Gandhinagar 382428, India ([email protected])
DHIRAJ BORA
Affiliation:
Institute for Plasma Research, Bhat, Gandhinagar 382428, India ([email protected])
Get access Rights & Permissions [Opens in a new window]

Abstract

Wave magnetic field components are measured across the radius (−10 cm ≤ r ≤ 10 cm) for a low-pressure (0.3 mbar) helicon discharge, in a toroidal vacuum chamber of small aspect ratio. Radial variation of the wave magnetic field components, measured during the helicon mode of the discharge, exhibit strong poloidal asymmetry which contribute significantly to the wave-induced helicity. The rise in the magnitude of the radial electric field with radiofrequency power, observed during discharge mode transition, supports better radial confinement of the plasma during the helicon mode of the discharge. The strong dependence of the plasma current on the helicon mode of the discharge has been observed during the present experimental study.

Type
Papers
Information
Journal of Plasma Physics , Volume 76 , Issue 1 , February 2010 , pp. 39 - 48
Copyright
Copyright © Cambridge University Press 2009

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

[1]Chavers, D. G., Chang-Diaz, F. R., Irvine, C. and Squire, J. P. 2006 Momentum and heat flux measurements using an impact target in flowing plasma. J. Propulsion Power 22, 637–644.CrossRefGoogle Scholar
[2]Scime, E. E., Keiter, P. A., Zintl, M. W., Balkey, M. M., Kline, J. L. and Koepke, M. E. 1998 Control of ion temperature anisotropy in a helicon plasma. Plasma Sources Sci. Technol. 7, 186–191.CrossRefGoogle Scholar
[3]Krämer, M., Aliev, M. Yu., Altukhov, A. B., Gurchenko, A. D., Gusakov, E. Z. and Niemi, K. 2007 Anomalous helicon wave absorption and parametric excitation of electrostatic fluctuations in a helicon-produced plasma. Plasma Phys. Control. Fusion 49, A167–A175.CrossRefGoogle Scholar
[4]Fisch, N. J. 1987 Theory of current drive in plasmas. Rev. Mod. Phys. 59, 175.CrossRefGoogle Scholar
[5]Tripathi, S. K. P. and Bora, D. 2002 Current drive by toroidally bounded whistlers. Nucl. Fusion 42, L15.CrossRefGoogle Scholar
[6]Takamura, S., Kojima, T. and Okuda, T. 1983 Radio Frequency current generation by helical slow-wave antennas in a torus. Plasma Phys. 25, 1469–1482.Google Scholar
[7]Zhang, B. C., Blackwell, B. D., Borg, G. G. and Petrižílka, V. 1997 Observation of the neoclassical current in the Small Heliac Experimental Apparatus (SHEILA). Phys. Plasmas 4 (11), 3986.CrossRefGoogle Scholar
[8]Paul, M. K. and Bora, D. 2007 Wave-induced helicity current drive by helicon waves. Phys. Plasmas 14, 082507.CrossRefGoogle Scholar
[9]Scime, E. E., Keesee, A. M. and Boswell, R. W. 2008 Mini-conference on helicon plasma sources. Phys. Plasmas 15, 058301.CrossRefGoogle Scholar
[10]Paul, M. K. and Bora, D. 2005 Helicon plasma production in a torus at very high frequency. Phys. Plasmas 12, 062510.CrossRefGoogle Scholar
[11]Paul, M. K. and Bora, D. 2008 Langmuir probe study in the nonresonant current drive regime of helicon discharge. Pramana 71 (1), 117.CrossRefGoogle Scholar
[12]Paul, M. K., Chattopadhyay, P. K. and Bora, D. 2007 Electrostatic pickup rejection in low plasma current measurement. Meas. Sci. Technol. 18, 117.CrossRefGoogle Scholar
[13]Franck, C. M., Grulke, O. and Klinger, T. 2002 Magnetic fluctuation probe design and capacitive pickup rejection. Rev. Sci. Instrum. 73 (11), 3768.CrossRefGoogle Scholar
[14]Tripathi, S. K. P. and Bora, D. 2001 Normal modes of bounded whistler produced toroidal plasmas. Phys. Plasmas 8, 697.Google Scholar
[15]Blackwell, D. D., Madziwa, T. G., Arnush, D. and Chen, F. F. 2002 Evidence for Trivelpiece–Gould modes in a helicon discharge. Phys. Rev. Lett. 88, 145002.CrossRefGoogle Scholar
[16]Light, M. and Chen, F. F. 1995 Helicon wave excitation with helical antennas. Phys. Plasmas 2, 1084.CrossRefGoogle Scholar
[17]Chen, F. F. 1991 Plasma ionization by helicon waves. Plasma Phys. Control. Fusion 33, 339.Google Scholar
[18]Paul, M. K. and Bora, D. 2009 Current drive by helicon waves. J. Appl. Phys. 105, 013305.CrossRefGoogle Scholar