title: HELIOS: a helium line-ratio spectral-monitoring diagnostic used to generate high resolution profiles near the ion cyclotron resonant heating antenna on TEXTOR.
abstract: Radial profiles of electron temperature and density are measured at high spatial (∼1 mm) and temporal (≥10 μs) resolution using a thermal supersonic helium jet. A highly accurate detection system is applied to well-developed collisional-radiative model codes to produce the profiles. Agreement between this measurement and an edge Thomson scattering measurement is found to be within the error bars (≲20%). The diagnostic is being used to give profiles near the ion cyclotron resonant heating antenna on TEXTOR to better understand RF coupling to the core.
authors.affiliation: Oak Ridge National Laboratory, Tennessee 37831-6169, USA. unterberge@fusion.gat.com
authors.forename: E A
authors.initials: EA
authors.lastname: Unterberg
authors.forename: O
authors.initials: O
authors.lastname: Schmitz
authors.forename: D H
authors.initials: DH
authors.lastname: Fehling
authors.forename: H
authors.initials: H
authors.lastname: Stoschus
authors.forename: C C
authors.initials: CC
authors.lastname: Klepper
authors.forename: J M
authors.initials: JM
authors.lastname: Muñoz-Burgos
authors.forename: G
authors.initials: G
authors.lastname: Van Wassenhove
authors.forename: D L
authors.initials: DL
authors.lastname: Hillis