title: Spontaneous formation of closed-field torus equilibrium via current jump observed in an electron-cyclotron-heated plasma.
abstract: Spontaneous current jump resulting in the formation of closed field equilibrium has been observed in electron-cyclotron-heated toroidal plasmas under steady external fields composed of a toroidal field and a relatively weak vertical field in the low aspect ratio torus experiment device. This bridges the gap between the open field equilibrium maintained by a pressure-driven current in the external field and the closed field equilibrium at a larger current. Experimental results and theoretical analyses suggest a current jump model that is based on the asymmetric electron confinement along the field line appearing upon simultaneous transitions of field topology and equilibrium.
authors.affiliation: Graduate School of Energy Science, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yoshinaga
authors.forename: M
authors.initials: M
authors.lastname: Uchida
authors.forename: H
authors.initials: H
authors.lastname: Tanaka
authors.forename: T
authors.initials: T
authors.lastname: Maekawa