title: Observations of improved stability and confinement in a high-beta self-organized spherical-torus-like field-reversed configuration.
abstract: An extremely high-beta (over 85%) self-organized field-reversed configuration (FRC) with a spherical-torus- (ST-)like core is produced in the translation, confinement, and sustainment experiment by highly super-Alfvénic translation of a spheromaklike plasmoid. Substantial flux conversion from toroidal into poloidal occurs during the capture process, resulting in the ST-like core. This plasma state exhibits a remarkable stabilizing property for the ubiquitous centrifugally driven interchange modes present in theta-pinch formed FRCs. This is explained, for the first time, by a simple model taking into account magnetic shear and centrifugal effects. The FRC-ST configuration has up to 4 times improvement in flux confinement times over the scaling of conventional theta-pinch formed FRCs and, thus, a significant improvement in the resistivity and transport.
authors.affiliation: Redmond Plasma Physics Laboratory, University of Washington, Seattle, Washington 98195, USA.
authors.forename: H Y
authors.initials: HY
authors.lastname: Guo
authors.forename: A L
authors.initials: AL
authors.lastname: Hoffman
authors.forename: L C
authors.initials: LC
authors.lastname: Steinhauer
authors.forename: K E
authors.initials: KE
authors.lastname: Miller