title: Effects of a vertical magnetic field on particle confinement in a magnetized plasma torus.
abstract: The particle confinement in a magnetized plasma torus with superimposed vertical magnetic field is modeled and measured experimentally. The formation of an equilibrium characterized by a parallel plasma current canceling out the grad B and curvature drifts is described using a two-fluid model. Characteristic response frequencies and relaxation rates are calculated. The predictions for the particle confinement time as a function of the vertical magnetic field are verified in a systematic experimental study on the TORPEX device, including the existence of an optimal vertical field and the anticorrelation between confinement time and density.
authors.affiliation: Centre de Recherches en Physique des Plasmas, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland. stefan.mueller@epfl.ch
authors.forename: S H
authors.initials: SH
authors.lastname: Müller
authors.forename: A
authors.initials: A
authors.lastname: Fasoli
authors.forename: B
authors.initials: B
authors.lastname: Labit
authors.forename: M
authors.initials: M
authors.lastname: McGrath
authors.forename: M
authors.initials: M
authors.lastname: Podestà
authors.forename: F M
authors.initials: FM
authors.lastname: Poli