[Table of Contents]

Plasma and Fusion Research

Volume 5, S2088 (2010)

Regular Articles

Charge-Exchanged Beam Measurement by Using a Grid-Biased Faraday Cup
Atsushi OKAMOTO, Takehiro ISONO, Tsuguhiro NISHIUCHI, Hiroyuki TAKAHASHI, Sumio KITAJIMA and Mamiko SASAO
Tohoku University, Sendai 980-8579, Japan
(Received 8 December 2009 / Accepted 4 March 2010 / Published 10 December 2010)

Abstract

A method for neutral beam measurement by using a Faraday cup is proposed in this paper. The method enables us to detect neutral beams by controlling secondary electrons by using a biasing grid in front of the Faraday cup. A procedure is also proposed for in situ determination of the secondary electron emission coefficient of the Faraday cup. Experimental results show that appropriate emission coefficients are determined for helium beams with energies of 2-10 keV. The neutral flux charge-exchanged from a helium ion beam passing through a helium gas is also measured. Saturation of the neutral flux is observed above the pressure expected from the solution of a rate equation. The method is promising for neutral beam measurement, especially for small current-neutral beams.

Keywords

neutral beam, charge exchange, secondary electron emission, grid-biased Faraday cup, rate equation

DOI: 10.1585/pfr.5.S2088

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References

  • [1] A. Okamoto, T. Isono, T. Kobuchi, S. Kitajima and M. Sasao, J. Plasma Fusion Res. SERIES 8, 39 (2009).
  • [2] A. Viehl, M. Kanyo, A. van der Hart and J. Schelten, Rev. Sci. Instrum. 64, 732 (1993).
  • [3] A. Okamoto, K. Iwazaki, T. Isono, T. Kobuchi, S. Kitajima and M. Sasao, Plasma Fusion Res. 3, 059 (2008).
  • [4] K. Shinto, H. Sugawara, M. Takenaga, S. Takeuchi, N. Tanaka, A. Okamoto, S. Kitajima, M. Sasao, M. Nishiura and M. Wada, Rev. Sci. Instrum. 77, 03B512 (2006).
  • [5] H. Sugawara, K. Shinto, N. Tanaka, S. Takeuchi, M. Kikuchi, A. Okamoto, S. Kitajima, M. Sasao and M. Wada, Rev. Sci. Instrum. 79, 02B708 (2008).
  • [6] Atomic Data for Controlled Fusion Research III (ORNL-6088), Ed. by E. W. Thomas, (Oak Ridge National Laboratory, USA, 1985) Chapter C.

This paper may be cited as follows:

Atsushi OKAMOTO, Takehiro ISONO, Tsuguhiro NISHIUCHI, Hiroyuki TAKAHASHI, Sumio KITAJIMA and Mamiko SASAO, Plasma Fusion Res. 5, S2088 (2010).