title: Nonlinear simulations of peeling-ballooning modes with anomalous electron viscosity and their role in edge localized mode crashes.
abstract: A minimum set of equations based on the peeling-ballooning (P-B) model with nonideal physics effects (diamagnetic drift, E×B drift, resistivity, and anomalous electron viscosity) is found to simulate pedestal collapse when using the new BOUT++ simulation code, developed in part from the original fluid edge code BOUT. Nonlinear simulations of P-B modes demonstrate that the P-B modes trigger magnetic reconnection, which leads to the pedestal collapse. With the addition of a model of the anomalous electron viscosity under the assumption that the electron viscosity is comparable to the anomalous electron thermal diffusivity, it is found from simulations using a realistic high-Lundquist number that the pedestal collapse is limited to the edge region and the edge localized mode (ELM) size is about 5%-10% of the pedestal stored energy. This is consistent with many observations of large ELMs.
authors.affiliation: Lawrence Livermore National Laboratory, California 94550, USA.
authors.forename: X Q
authors.initials: XQ
authors.lastname: Xu
authors.forename: B
authors.initials: B
authors.lastname: Dudson
authors.forename: P B
authors.initials: PB
authors.lastname: Snyder
authors.forename: M V
authors.initials: MV
authors.lastname: Umansky
authors.forename: H
authors.initials: H
authors.lastname: Wilson