[Table of Contents]

Plasma and Fusion Research

Volume 5, S1046 (2010)

Regular Articles

A Movable Thomson Scattering System Based on Optical Fibers (TS-Probe)
Kazumichi NARIHARA and Hiroshi HAYASHI
National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
(Received 9 January 2009 / Accepted 8 July 2009 / Published 26 March 2010)

Abstract

This paper proposes a movable compact Thomson scattering (TS) system based on optical fibers (TS-probe). The TS-probe consists of a probe head, optical fibers, a laser diode, a polychromator, and lock-in amplifiers. Laser beam optics and light collection optics are mounted rigidly on a probe head with a fixed scattering position. Laser light and scattered light are transmitted by flexible optical fibers, enabling us to move the TS-probe head freely during plasma discharge. The light signal scattered from an amplitude-modulated laser is detected against the plasma light based on the principle of the lock-in amplifier. With a modulated laser power of 300 W, the scattered signal from a sheet plasma 15 mm deep with ne ∼1019 m−3 can be measured with 10 % accuracy by setting the integrating time to 0.1 s. The TS-probe head is similar to a 1/20 model of the currently operating Large Helical Device-TS.

Keywords

Thomson scattering system, fiber laser, divertor plasma, TS-probe, LHD

DOI: 10.1585/pfr.5.S1046

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References

  • [1] K. Narihara et al., Fusion Eng. Des. 34-35, 67 (1997).
  • [2] Diaguide, Mitsubishi-cable Catalog 2000. 07 (in Japanese).
  • [3] http://www.lewvac.co.uk.
  • [4] http://www.LIMO.de.
  • [5] Laser Focus World Japan 8, 52 (2008).
  • [6] C. Moser, L. Ho, E. Maye and F. Havermeyer, J. Phys. D: Appl. Phys. 41, 224003 (2008).
  • [7] http://www.Thinkers.com/products/SR844.htm.
  • [8] A. van der Ziel, Noise, Prentice-Hall, Inc, 1954.
  • [9] R. J. McIntyre, IEEE Trans. Electron Devices ED-13, 164 (1966).
  • [10] ‘The Avalanche Photodiode Catalog', Advanced Photonix, Inc.

This paper may be cited as follows:

Kazumichi NARIHARA and Hiroshi HAYASHI, Plasma Fusion Res. 5, S1046 (2010).