Plasma and Fusion Research

Volume 6, 2402094 (2011)

Regular Articles

Broadband Multichannel Radiometer for ECE Measurements on KSTAR
Kazuo KAWAHATA, Yoshio NAGAYAMA, Hayato TSUCHIYA, Atsushi MASE1), Yuichiro KOGI2), Seung Ho JEONG3), Kyu-Dong LEE4) and Richard J. WYLDE5)
National Institute for Fusion Science, Toki 509-5292, Japan
1)
KASTEC, Kyushu University, Kasuga 816-8580, Japan
2)
Fukuoka Institute of Technology, Fukuoka 811-0295, Japan
3)
Korea Atomic Energy Research Institute, Daejeon, Korea
4)
National Fusion Research Institute, Daejeon, Korea
5)
Thomas Keating Ltd., Station Mills, Billinghurst, West Sussex RH114 9SH, UK
(Received 6 December 2010 / Accepted 24 February 2011 / Published 12 July 2011)

Abstract

A broadband heterodyne radiometer system has been developed and installed on KSTAR to measure second harmonic electron cyclotron emission (ECE) at the magnetic field of 3 T. The system consisting of two radiometers (110-162 GHz and 164-196 GHz) can cover a frequency range of 110-196 GHz. The unique and key components to construct this ECE diagnostic instrument are specially-designed detector modules and a diplexer for splitting ECE radiation with high efficiency. The minimum detectable electron temperature with a time response of 1 µs is about 0.23 eV. The observed signal intensity is roughly consistent with the value estimated by using characteristics of various components (waveguide components, sub-harmonic mixers, amplifiers, and intermediate frequency detectors). In this article, design considerations and preliminary ECE measurements will be described.

Keywords

electron cyclotron emission, heterodyne radiometer, electron temperature, tokamak plasma, KSTAR

DOI: 10.1585/pfr.6.2402094

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This paper may be cited as follows:

Kazuo KAWAHATA, Yoshio NAGAYAMA, Hayato TSUCHIYA, Atsushi MASE, Yuichiro KOGI, Seung Ho JEONG, Kyu-Dong LEE and Richard J. WYLDE, Plasma Fusion Res. 6, 2402094 (2011).