title: Experimental demonstration of improved neoclassical transport with quasihelical symmetry.
abstract: Differences in the electron particle and thermal transport are reported between plasmas produced in a quasihelically symmetric (QHS) magnetic field and a configuration with the symmetry broken. The thermal diffusivity is reduced in the QHS configuration, resulting in higher electron temperatures than in the nonsymmetric configuration for a fixed power input. The density profile in QHS plasmas is centrally peaked, and in the nonsymmetric configuration the core density profile is hollow. The hollow profile is due to neoclassical thermodiffusion, which is reduced in the QHS configuration.
authors.affiliation: Department of Electrical and Computer Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Canik
authors.forename: D T
authors.initials: DT
authors.lastname: Anderson
authors.forename: F S B
authors.initials: FS
authors.lastname: Anderson
authors.forename: K M
authors.initials: KM
authors.lastname: Likin
authors.forename: J N
authors.initials: JN
authors.lastname: Talmadge
authors.forename: K
authors.initials: K
authors.lastname: Zhai