[Table of Contents]

Plasma and Fusion Research

Volume 2, S1064 (2007)

Regular Articles

Design of Soft-X Ray Imaging System for Magnetic Islands of RFP Plasmas
Akio SANPEI, Takumi ONCHI, Ryuya IKEZOE, Haruhiko HIMURA and Sadao MASAMUNE
Department of Electronics, Kyoto Institute of Technology, Kyoto 606-8585, Japan
(Received 10 December 2006 / Accepted 23 May 2007 / Published 20 November 2007)

Abstract

A soft X ray (SXR) imaging system for diagnosing magnetic islands of a reversed field pinch (RFP) plasma is proposed. The SXR imaging system utilizes a microchannel plate (MCP) to record a higher-resolution distribution of two-dimensional (2D) luminosity on a phosphor plate. In order to identify the structure of the magnetic island from the obtained SXR image, we have calculated the 2D image expected from RFP plasmas. It is found that the 2D image reflects the change in the radiation intensity caused by the magnetic island. Also, the magnetic island can be distinguished clearly when the radiation power emitted from the magnetic island is more than about 20 % of that on the magnetic axis of RFP. Regarding with the view angle α of the SXR imaging system, the magnetic island due to a tearing mode on the m = 1/n = 8 rational surface can be detected as far as α > π/10.

Keywords

RFP, soft-x ray, imaging, magnetic island

DOI: 10.1585/pfr.2.S1064

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References

  • [1] I.H. Hutchinson, Principles of Plasma Diagnostics Cambridge University Press, Cambridge (1987).
  • [2] T. Nash, C. Deeney, P.D. LePell, R. Prasad and M. Krishnan, Rev. Sci. Instrum. 61, 2807 (1990).
  • [3] E.A. Crowford, D.P. Taggart and A.D. Bailey III, Rev. Sci. Instrum. 61, 2795 (1990).
  • [4] N.R. Sauthoff, S. von Goeler and W.F. Stodiek, Nucl. Fusion 18, 1445 (1985).
  • [5] R.Z. Granetz and J.F. Camacho, Nucl. Fusion 25, 727 (1985).
  • [6] H. Koguchi et al., Rev. Sci. Instrum. 75, 4004 (2004).
  • [7] S. Masamune, M. Iida, N. Oda, K. Fujitsuka, M. Awazu, K. Ohta, H. Oshiyama, Fusion Energy 21, 201 (1996).
  • [8] S. Masamune, M. Iida, Y. Ohfuji, K. Ohta, H. Oshiyama, Plasma Phys. Control. Fusion 40, 127 (1998).
  • [9] S. Masamune and M. Iida, J. Plasma Fusion Res. SERIES 5, 509 (2002).
  • [10] T. Onchi, A. Sanpei, R. Ikezoe et al., poster P6-26 in this conference.
  • [11] P. Franz, L. Marrelli, P. Piovesan et al., Phys. Rev. Lett. 92, 125001 (2004).

This paper may be cited as follows:

Akio SANPEI, Takumi ONCHI, Ryuya IKEZOE, Haruhiko HIMURA and Sadao MASAMUNE, Plasma Fusion Res. 2, S1064 (2007).