title: Neoclassical transport caused by collisionless scattering across an asymmetric separatrix.
abstract: Plasma loss due to apparatus asymmetries is a ubiquitous phenomenon in magnetic plasma confinement. When the plasma equilibrium has locally trapped particle populations partitioned by a separatrix from one another and from passing particles, the asymmetry transport is enhanced. The trapped and passing particle populations react differently to the asymmetries, leading to the standard 1/ν and sqrt[ν] transport regimes of superbanana orbit theory as particles collisionally scatter from one orbit type to another. However, when the separatrix is itself asymmetric, particles can collisionlessly transit from trapped to passing and back, leading to enhanced transport.
authors.affiliation: Department of Physics, University of California, San Diego, La Jolla, California 92093, USA.
authors.forename: Daniel H E
authors.initials: DH
authors.lastname: Dubin
authors.forename: C F
authors.initials: CF
authors.lastname: Driscoll
authors.forename: Yu A
authors.initials: YA
authors.lastname: Tsidulko