Plasma and Fusion Research

Volume 14, 2401005 (2019)

Regular Articles

High-Density Plasma Production in Converging Field Following a Magnetic Beach Plasma Source
Atsushi OKAMOTO, Ryosuke OCHIAI, Katsuya SATOU, Hiroki HACHIKUBO, Minami SUGIMOTO, Takaaki FUJITA and Hiroyuki TAKAHASHI1)
Nagoya University, Nagoya 464-8603, Japan
1)
Tohoku University, Sendai 980-8579, Japan
(Received 28 September 2018 / Accepted 16 November 2018 / Published 24 January 2019)

Abstract

A high ion saturation current (Iis) phase, which is characterized by larger increase/decrease of Iis compared with the magnetic field variation, is observed in a converging field following an electron cyclotron resonance plasma source with a magnetic beach configuration. Plasma production rate and particle influx are considered in terms of orbits of collisionless electrons. While the ionization probability of one-pass electron is order of 0.1, the mirror trapped electron cause ionization within several or dozen bouncing. This is an essence of improved ionization rate resulting in the high Iis phase. The temporal evolution of ion saturation current observed in the experiment is well explained by the estimated plasma production rate and particle influx.

Keywords

electron cyclotron resonance, magnetic beach configuration, converging magnetic field, bounce motion, pitch angle, high-density plasma

DOI: 10.1585/pfr.14.2401005

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References

  • [1] N. Ohno et al., Nucl. Fusion 41, 1055 (2001).
  • [2] E.M. Hollmann et al., Phys. Plasmas 9, 1226 (2002).
  • [3] A. Okamoto et al., J. Nucl. Mater. 363-365, 395 (2007).
  • [4] H. Takahashi et al., Phys. Plasmas 23, 112510 (2016).
  • [5] Y. Zhang et al., Phys. Plasmas 15, 102112 (2008).
  • [6] H. Shoyama et al., J. Phys. Soc. Jpn. 65, 2860 (1996).
  • [7] M. Tanaka et al., J. Phys. Soc. Jpn. 60, 1600 (1991).
  • [8] D. Hamada et al., Plasma Fusion Res. 13, 3401044 (2018).