title: High resolution main-ion charge exchange spectroscopy in the DIII-D H-mode pedestal.
abstract: A new high spatial resolution main-ion (deuterium) charge-exchange spectroscopy system covering the tokamak boundary region has been installed on the DIII-D tokamak. Sixteen new edge main-ion charge-exchange recombination sightlines have been combined with nineteen impurity sightlines in a tangentially viewing geometry on the DIII-D midplane with an interleaving design that achieves 8 mm inter-channel radial resolution for detailed profiles of main-ion temperature, velocity, charge-exchange emission, and neutral beam emission. At the plasma boundary, we find a strong enhancement of the main-ion toroidal velocity that exceeds the impurity velocity by a factor of two. The unique combination of experimentally measured main-ion and impurity profiles provides a powerful quasi-neutrality constraint for reconstruction of tokamak H-mode pedestals.
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543, USA.
authors.forename: B A
authors.initials: BA
authors.lastname: Grierson
authors.affiliation: General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA.
authors.forename: K H
authors.initials: KH
authors.lastname: Burrell
authors.affiliation: Oak Ridge Associated Universities, Oak Ridge, Tennessee 37831, USA.
authors.forename: C
authors.initials: C
authors.lastname: Chrystal
authors.affiliation: General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Groebner
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543, USA.
authors.forename: S R
authors.initials: SR
authors.lastname: Haskey
authors.affiliation: General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA.
authors.forename: D H
authors.initials: DH
authors.lastname: Kaplan