title: Collective backscattering of gyrotron radiation by small-scale plasma density fluctuations in large helical device.
abstract: 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(s) approximately 34 cm(-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.
authors.affiliation: A.M. Prokhorov General Physics Institute, Vavilova 38, 119991 Moscow, Russia. khar@fpl.gpi.ru
authors.forename: Nikolay
authors.initials: N
authors.lastname: Kharchev
authors.forename: Kenji
authors.initials: K
authors.lastname: Tanaka
authors.forename: Shin
authors.initials: S
authors.lastname: Kubo
authors.forename: Hiroe
authors.initials: H
authors.lastname: Igami
authors.forename: German
authors.initials: G
authors.lastname: Batanov
authors.forename: Alexandr
authors.initials: A
authors.lastname: Petrov
authors.forename: Karen
authors.initials: K
authors.lastname: Sarksyan
authors.forename: Nina
authors.initials: N
authors.lastname: Skvortsova
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Azuma
authors.forename: Shunji
authors.initials: S
authors.lastname: Tsuji-Iio