Collective backscattering of gyrotron radiation by small-scale plasma density fluctuations in large helical device

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

DOI:https://doi.org/10.1063/1.2982774· OSTI ID:21266545

Kharchev, Nikolay; Batanov, German; Petrov, Alexandr; Sarksyan, Karen; Skvortsova, Nina ^[1]; Tanaka, Kenji; Kubo, Shin; Igami, Hiroe ^[2]; Azuma, Yoshifumi; Tsuji-Iio, Shunji ^[3]

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1. A.M. Prokhorov General Physics Institute, Vavilova 38, 119991 Moscow (Russian Federation)
2. National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, Gifu 509-5292 (Japan)
3. Tokyo Institute of Technology, 2-12-1-N1-11, Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)

A version of the collective backscattering diagnostic using gyrotron radiation for small-scale turbulence is described. The diagnostic is used to measure small-scale (k{sub s}{approx_equal}34 cm{sup -1}) plasma density fluctuations in large helical device experiments on the electron cyclotron heating of plasma with the use of 200 kW 82.7 GHz heating gyrotron. A good signal to noise ratio during plasma production phase was obtained, while contamination of stray light increased during plasma build-up phase. The effect of the stray radiation was investigated. The available quasioptical system of the heating system was utilized for this purpose.

• OSTI ID: 21266545
• Journal Information: Review of Scientific Instruments, Vol. 79, Issue 10; Other Information: DOI: 10.1063/1.2982774; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BACKSCATTERING
ECR HEATING
FLUCTUATIONS
GHZ RANGE
HEATING SYSTEMS
LHD DEVICE
MICROWAVE AMPLIFIERS
PLASMA
PLASMA DENSITY
PLASMA DIAGNOSTICS
PLASMA PRODUCTION
SIGNAL-TO-NOISE RATIO
STRAY RADIATION
TURBULENCE