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Measurement of lower-hybrid current profile using interferometry and reflectometry methods at electron-cyclotron wave frequencies

Conference:

Abstract

A central problem in lower-hybrid current drive is the effective penetration of the driven current in the plasma region. Substantial progress can only be made if accurate and direct measurements of the radial profile of the rf-driven current density J (r) are performed. Here we discuss two methods: the first is based on microwave transmission along vertical chords at frequency {omega} lower than the electron gyrofrequency {omega}{sub c} and is appropriate for low-density plasmas. The second consists in measuring the attenuation of an ordinary mode reflected by the cut-off at the plasma frequency {omega}{sub p}, and is appropriate for high-density plasmas. Both methods exploit the proportionality between the local absorption coefficient for the LH tail at {omega} < {omega}{sub c} and the parallel distribution function, which allows the inversion of the measured transmission spectra, yielding J (r).
Publication Date:
Dec 31, 1991
Product Type:
Conference
Report Number:
CEA-CONF-10740; CONF-910869-
Reference Number:
SCA: 700350; PA: FRD-92:000737; SN: 92000658028
Resource Relation:
Conference: 9. topical conference on radio frequency power in plasmas,Charleston, SC (United States),19-21 Aug 1991; Other Information: PBD: 1991
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; LOWER HYBRID CURRENT DRIVE; PLASMA RADIAL PROFILES; INTERFEROMETRY; REFLECTION; ELECTRON CYCLOTRON-RESONANCE; CURRENT DENSITY; RF SYSTEMS; 700350; PLASMA PRODUCTION, HEATING, CURRENT DRIVE, AND INTERACTIONS
OSTI ID:
10116498
Research Organizations:
Association Euratom-CEA, Centre d`Etudes Nucleaires de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee
Country of Origin:
France
Language:
English
Other Identifying Numbers:
Other: ON: DE92767124; TRN: FR9200737
Availability:
OSTI; NTIS (US Sales Only)
Submitting Site:
FRN
Size:
4 p.
Announcement Date:
Feb 25, 1992

Conference:

Citation Formats

Fidone, I, and Giruzzi, G. Measurement of lower-hybrid current profile using interferometry and reflectometry methods at electron-cyclotron wave frequencies. France: N. p., 1991. Web.
Fidone, I, & Giruzzi, G. Measurement of lower-hybrid current profile using interferometry and reflectometry methods at electron-cyclotron wave frequencies. France.
Fidone, I, and Giruzzi, G. 1991. "Measurement of lower-hybrid current profile using interferometry and reflectometry methods at electron-cyclotron wave frequencies." France.
@misc{etde_10116498,
title = {Measurement of lower-hybrid current profile using interferometry and reflectometry methods at electron-cyclotron wave frequencies}
author = {Fidone, I, and Giruzzi, G}
abstractNote = {A central problem in lower-hybrid current drive is the effective penetration of the driven current in the plasma region. Substantial progress can only be made if accurate and direct measurements of the radial profile of the rf-driven current density J (r) are performed. Here we discuss two methods: the first is based on microwave transmission along vertical chords at frequency {omega} lower than the electron gyrofrequency {omega}{sub c} and is appropriate for low-density plasmas. The second consists in measuring the attenuation of an ordinary mode reflected by the cut-off at the plasma frequency {omega}{sub p}, and is appropriate for high-density plasmas. Both methods exploit the proportionality between the local absorption coefficient for the LH tail at {omega} < {omega}{sub c} and the parallel distribution function, which allows the inversion of the measured transmission spectra, yielding J (r).}
place = {France}
year = {1991}
month = {Dec}
}