Plasma and Fusion Research

Volume 5, S2063 (2010)

Regular Articles

Recent Progress in Low-A RFP Plasma Research in RELAX
Akio SANPEI, Ryuya IKEZOE, Takumi ONCHI, Kensuke OKI, Masaki SUGIHARA, Yuusuke KONISHI, Shin-ichi FUJITA, Mitsuru NAKAMURA, Akio HIGASHI, Hidehiko MOTOI, Haruhiko HIMURA and Sadao MASAMUNE
Kyoto Institute of Technology, Kyoto 606-8585, Japan
(Received 24 January 2010 / Accepted 18 May 2010 / Published 10 December 2010)

Abstract

Recent results from a low-aspect-ratio (low-A) reversed field pinch (RFP) machine with an aspect ratio of 2 (R/a = 0.51/0.25) are reported. The discharge characteristics of low-A RFP plasmas are described. The discharge regime in F − Θ space indicates that lowering the aspect ratio expanded the operational F − Θ space to the extremely high-Θ (> 3), deep-reversal (F < −1) region and to the non reversal (F > 0) region. A rotating helical Ohmic equilibrium RFP state could be realized in shallow-reversal discharge on REversed field pinch of Low Aspect eXperiment (RELAX). A preliminary feedback system is developed that results in plasma current with a longer discharge duration of ∼2 ms.

Keywords

reversed field pinch (RFP), low-aspect ratio (low-A), nonlinear MHD

DOI: 10.1585/pfr.5.S2063

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References

  • [1] M. D. Wyman et al., Phys. Plasmas. 15, 010701 (2008).
  • [2] H. Koguchi et al., Plasma Fusion Res. 2, 050 (2007).
  • [3] R. Lorenzini et al., Nature Physics 5, 570 (2009).
  • [4] S. Shiina et al., Phys. Plasmas. 12, 080702 (2005).
  • [5] S. Masamune et al., J. Phys. Soc. Jpn. 76, 123501 (2007).
  • [6] T. Onchi et al., Plasma Fusion Res. 3, 005 (2008).
  • [7] K. Oki et al., J. Phys. Soc. Jpn. 77, 075005 (2008).
  • [8] A. Sanpei et al., J. Phys. Soc. Jpn. 78, 013501 (2009).
  • [9] M. Sugihara et al., poster P2-34 in this conference.
  • [10] R. Ikezoe et al., J. Plasma Fusion Res. SERIES 8, 1031 (2009).
  • [11] R. Paccagnella, presented at IEA/RFP Workshop, Madison (2000).
  • [12] P. R. Brunsell et al., Phys. Rev. Lett. 93, 225001 (2004).

This paper may be cited as follows:

Akio SANPEI, Ryuya IKEZOE, Takumi ONCHI, Kensuke OKI, Masaki SUGIHARA, Yuusuke KONISHI, Shin-ichi FUJITA, Mitsuru NAKAMURA, Akio HIGASHI, Hidehiko MOTOI, Haruhiko HIMURA and Sadao MASAMUNE, Plasma Fusion Res. 5, S2063 (2010).