title: Probing the plasma near high power wave launchers in fusion devices for static and dynamic electric fields (invited).
abstract: An exploratory study was carried out in the long-pulse tokamak Tore Supra, to determine if electric fields in the plasma around high-power, RF wave launchers could be measured with non-intrusive, passive, optical emission spectroscopy. The focus was in particular on the use of the external electric field Stark effect. The feasibility was found to be strongly dependent on the spatial extent of the electric fields and overlap between regions of strong (>∼1 kV/cm) electric fields and regions of plasma particle recycling and plasma-induced, spectral line emission. Most amenable to the measurement was the RF electric field in edge plasma, in front of a lower hybrid heating and current drive launcher. Electric field strengths and direction, derived from fitting the acquired spectra to a model including time-dependent Stark effect and the tokamak-range magnetic field Zeeman-effect, were found to be in good agreement with full-wave modeling of the observed launcher.
authors.affiliation: Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6169, USA.
authors.forename: C C
authors.initials: CC
authors.lastname: Klepper
authors.affiliation: Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6169, USA.
authors.forename: E H
authors.initials: EH
authors.lastname: Martin
authors.affiliation: Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6169, USA.
authors.forename: R C
authors.initials: RC
authors.lastname: Isler
authors.affiliation: CEA, IRFM, F-13108 Saint Paul-lez-Durance, France.
authors.forename: L
authors.initials: L
authors.lastname: Colas
authors.affiliation: CEA, IRFM, F-13108 Saint Paul-lez-Durance, France.
authors.forename: M
authors.initials: M
authors.lastname: Goniche
authors.affiliation: CEA, IRFM, F-13108 Saint Paul-lez-Durance, France.
authors.forename: J
authors.initials: J
authors.lastname: Hillairet
authors.affiliation: CEA, IRFM, F-13108 Saint Paul-lez-Durance, France.
authors.forename: S
authors.initials: S
authors.lastname: Panayotis
authors.affiliation: CEA, IRFM, F-13108 Saint Paul-lez-Durance, France.
authors.forename: B
authors.initials: B
authors.lastname: Pegourié
authors.affiliation: CEA, IRFM, F-13108 Saint Paul-lez-Durance, France.
authors.forename: J
authors.initials: J
authors.lastname: Jacquot
authors.affiliation: CEA, IRFM, F-13108 Saint Paul-lez-Durance, France.
authors.forename: Ph
authors.initials: P
authors.lastname: Lotte
authors.affiliation: CEA, IRFM, F-13108 Saint Paul-lez-Durance, France.
authors.forename: G
authors.initials: G
authors.lastname: Colledani
authors.affiliation: Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6169, USA.
authors.forename: T M
authors.initials: TM
authors.lastname: Biewer
authors.affiliation: Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6169, USA.
authors.forename: J B
authors.initials: JB
authors.lastname: Caughman
authors.affiliation: CEA, IRFM, F-13108 Saint Paul-lez-Durance, France.
authors.forename: A
authors.initials: A
authors.lastname: Ekedahl
authors.affiliation: Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6169, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Green
authors.affiliation: Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6169, USA.
authors.forename: J H
authors.initials: JH
authors.lastname: Harris
authors.affiliation: Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6169, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Hillis
authors.affiliation: North Carolina State University, Raleigh, North Carolina 27607, USA.
authors.forename: S C
authors.initials: SC
authors.lastname: Shannon
authors.affiliation: CEA, IRFM, F-13108 Saint Paul-lez-Durance, France.
authors.forename: X
authors.initials: X
authors.lastname: Litaudon