Design of collective Thomson scattering system using 77 GHz gyrotron for bulk and tail ion diagnostics in the large helical device

Journal Article · Wed Oct 15 04:00:00 EDT 2008 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.2978201· OSTI ID:21266554

Nishiura, M; Tanaka, K; Kubo, S; Kawahata, K; Shimozuma, T; Mutoh, T ^[1]; Saito, T; Tatematsu, Y; Notake, T ^[2]

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1. National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan)
2. Research Center for Development of Far-Infrared Region, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507 (Japan)

Collective Thomson scattering (CTS) system is expected to be a strong diagnostic tool for measuring thermal and fast ion distribution function at a local point inside plasmas. The electron cyclotron resonance heating system using a gyrotron at the frequency range of 77 GHz has been installed at the large helical device (LHD). The feasibility of CTS system using the 77 GHz gyrotron is assessed in terms of scattering spectrum and a background noise of the electron cyclotron emission, which affect the signal to noise ratio, with the realistic plasma parameters and incident port locations of LHD. Based on the calculated scattering spectra for bulk and tail fast ion diagnostics, the scattering radiation receiver system with gyrotron frequency feedback circuit is proposed to avoid the frequency chirping.

• OSTI ID: 21266554
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 10 Vol. 79; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BACKGROUND NOISE
DESIGN
DISTRIBUTION FUNCTIONS
ECR HEATING
ELECTRONS
FEEDBACK
GHZ RANGE
LHD DEVICE
MICROWAVE AMPLIFIERS
PLASMA
PLASMA DIAGNOSTICS
RF SYSTEMS
SIGNAL-TO-NOISE RATIO
SPECTRA
TAIL IONS
THOMSON SCATTERING