title: Flux conversion and evidence of relaxation in a high-beta plasma formed by high-speed injection into a mirror confinement structure.
abstract: High-beta plasmoids can survive the violent dynamics of supersonic reflection off mirror structures, producing a stable high-beta field-reversed configuration (FRC). This shows both the robustness of FRCs and their tendency to assume a preferred plasma state, possibly conforming to a relaxation principle. The key observations are (1) approximate preservation of the magnetic helicity, (2) substantial conversion from toroidal to poloidal magnetic flux, (3) substantial toroidal flow, and (4) a high-beta quiescent final state. These results are from the Translation, Confinement, and Sustainment experiment where a disorganized plasmoid is injected at super-Alfvenic speed into a confinement chamber. After successive reflections from end mirrors, the plasmoid settled into a near-FRC state with high beta and low toroidal magnetic field. The flux conversion and helicity preservation are inferred by an interpretive model.
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: K E
authors.initials: KE
authors.lastname: Miller
authors.forename: L C
authors.initials: LC
authors.lastname: Steinhauer