title: Vertical pairing of identical particles suspended in the plasma sheath.
abstract: It is shown experimentally that vertical pairing of two identical microspheres suspended in the sheath of a radio-frequency (rf) discharge at low gas pressures (a few Pa) appears at a well-defined instability threshold of the rf power. The transition is reversible, but with significant hysteresis on the second stage. A simple model which uses measured microsphere resonance frequencies and takes into account, in addition to the Coulomb interaction between negatively charged microspheres, their interaction with positive-ion-wake charges, seems to explain the instability threshold quite well.
authors.affiliation: Max-Planck-Institut für Extraterrestrische Physik, D-85740 Garching, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Steinberg
authors.forename: R
authors.initials: R
authors.lastname: Sütterlin
authors.forename: A V
authors.initials: AV
authors.lastname: Ivlev
authors.forename: G
authors.initials: G
authors.lastname: Morfill