Regular Articles

Full Text / References

Estimation of the Effective Collective Thomson Scattering Volume Using a Gaussian Beam in the LHD ECRH System

Shin KUBO, Masaki NISHIURA, Namiko TAMURA¹⁾, Kenji TANAKA, Takashi SHIMOZUMA, Yoshinori TATEMATSU²⁾, Teruo SAITO²⁾, Yasuo YOSHIMURA, Hiroe IGAMI, Hiromi TAKAHASHI, Ryosuke IKEDA²⁾ and Takashi MUTOH

National Institute for Fusion Science,322-6 Oroshi-cho, Toki 509-5292, Japan

1)

Department of Energy Science and Technology, Nagoya University, Nagoya 464-8463, Japan

2)

Research Center for Development of Far-Infrared Region, University of Fukui, Fukui 910-8507, Japan

(Received 6 January 2009 / Accepted 2 March 2010 / Published 10 December 2010)

Abstract

Collective Thomson scattering (CTS) is a promising candidate for direct measurement of the velocity distribution function of ions in fusion devices. The relevant frequency for a CTS probing beam source is in the millimeter- to submillimeter-wave range. The scattering volume of CTS is an important parameter for determining the intensity of the scattered power and the spatial resolution of the measurement. The conventional method of estimating the scattering volume is to simply calculate the geometrical volume of the probing and receiving beams. This calculation is valid only when the beams are diffraction free. The effective scattering volume is defined and applied to a CTS system using strongly focused beams and its validity is examined experimentally.

Copyright (c) 2010 The Japan Society of Plasma Science and Nuclear Fusion Research

Keywords

collective Thomson scattering, ECRH, gyrotron, Gaussian beam, scattering volume

DOI: 10.1585/pfr.5.S2103

Full Text

PDF format (1.5Mbytes)

References

• [1] H. Bindslev, S. K. Nielsen, L. Porte, J. A. Hoekzema, S. B. Korsholm, F. Meo, P. K. Michelsen, S. Michelsen, J. W. Oosterbeek, E. L. Tsakadze, E. Westerhof and P. Woskov, Phys. Rev. Lett. 97, 205005 (2006).
• [2] F. Meo, H. Bindslev, S. B. Kolsholm, E. L. Tsakadze, C. I. Walker et al., Rev. Sci. Instrum. 75, 3585 (2004).
• [3] M. Nishiura, K. Tanaka, S. Kubo, T. Saito, Y. Tatematsu et al., Rev. Sci. Instrum. 79, 10E731 (2008).
• [4] S. Kubo, M. Nishiura, K. Tanaka, T. Shimozuma, Y. Tatematsu, T. Notake, T. Saito, Y. Yoshimura, H. Igami, H. Takahashi and N. Tamura, to be published in PFR (2010).
• [5] J. Sheffield, “Plasma Scattering of Electro-manetic Radiation”, Academic Press, New York, 1975, eq.(2.3.17).
• [6] S. Kubo, T. Shimozuma, Y. Yoshimura, H. Igami, H. Takahashi et al., Proc. 22nd IAEA Fusion Energy Conference, 13-18 October 2008 Geneva, Switzerland. EX/P6-14.

This paper may be cited as follows:

Shin KUBO, Masaki NISHIURA, Namiko TAMURA, Kenji TANAKA, Takashi SHIMOZUMA, Yoshinori TATEMATSU, Teruo SAITO, Yasuo YOSHIMURA, Hiroe IGAMI, Hiromi TAKAHASHI, Ryosuke IKEDA and Takashi MUTOH, Plasma Fusion Res. 5, S2103 (2010).