title: Extreme heat fluxes in gyrokinetic simulations: a new critical β.
abstract: A hitherto unexplained feature of electromagnetic simulations of ion temperature gradient turbulence is the apparent failure of the transport levels to saturate for certain parameters; this effect, termed here nonzonal transition, has been referred to as the high-β runaway. The resulting large heat fluxes are shown to be a consequence of reduced zonal flow activity, brought on by magnetic field perturbations shorting out flux surfaces.
authors.affiliation: University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Pueschel
authors.affiliation: University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: P W
authors.initials: PW
authors.lastname: Terry
authors.affiliation: Max-Planck-Institut für Plasmaphysik, EURATOM Association, D-85748 Garching, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Jenko
authors.affiliation: Max-Planck-Institut für Plasmaphysik, EURATOM Association, D-85748 Garching, Germany.
authors.forename: D R
authors.initials: DR
authors.lastname: Hatch
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94551, USA.
authors.forename: W M
authors.initials: WM
authors.lastname: Nevins
authors.affiliation: Max-Planck-Institut für Plasmaphysik, EURATOM Association, D-85748 Garching, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Görler
authors.affiliation: Max-Planck-Institut für Plasmaphysik, EURATOM Association, D-85748 Garching, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Told