title: Measurement of the interaction force among particles in three-dimensional plasma clusters.
abstract: The interaction forces between particles have been studied in a 3D plasma cluster under weak external confinement. A suitable combination of dc and rf applied to a small electrode provided gravity compensation, uniform over dimensions much larger than the cluster itself. The forces acting on the particles could be reconstructed due to unique three-dimensional diagnostics, which allow us to obtain coordinates and velocities of all the particles simultaneously. The measurements yield a maximum (external) confinement force of 1.4 x 10(-15)N and interparticle force that is repulsive at short distances and attractive at larger distances, with a maximum attractive force of 2.4 X 10(-14)N at particle separation 195 microm.
authors.affiliation: Max-Planck Institut für extraterrestrische Physik, D-85740 Garching, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Antonova
authors.forename: B M
authors.initials: BM
authors.lastname: Annaratone
authors.forename: D D
authors.initials: DD
authors.lastname: Goldbeck
authors.forename: V
authors.initials: V
authors.lastname: Yaroshenko
authors.forename: H M
authors.initials: HM
authors.lastname: Thomas
authors.forename: G E
authors.initials: GE
authors.lastname: Morfill