title: Stirring unmagnetized plasma.
abstract: A new concept for spinning unmagnetized plasma is demonstrated experimentally. Plasma is confined by an axisymmetric multicusp magnetic field and biased cathodes are used to drive currents and impart a torque in the magnetized edge. Measurements show that flow viscously couples momentum from the magnetized edge (where the plasma viscosity is small) into the unmagnetized core (where the viscosity is large) and that the core rotates as a solid body. To be effective, collisional viscosity must overcome the ion-neutral drag due to charge-exchange collisions.
authors.affiliation: Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA. cscollins2@wisc.edu
authors.forename: C
authors.initials: C
authors.lastname: Collins
authors.forename: N
authors.initials: N
authors.lastname: Katz
authors.forename: J
authors.initials: J
authors.lastname: Wallace
authors.forename: J
authors.initials: J
authors.lastname: Jara-Almonte
authors.forename: I
authors.initials: I
authors.lastname: Reese
authors.forename: E
authors.initials: E
authors.lastname: Zweibel
authors.forename: C B
authors.initials: CB
authors.lastname: Forest