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S Ratynskaia

Publications and source records attributed to S Ratynskaia.

3 recordsLinked to original sources

Superdiffusion and viscoelastic vortex flows in a two-dimensional complex plasma.

Viscoelastic vortical fluid motion in a strongly coupled particle system has been observed experimentally. Optical tracking of particle motion in a complex plasma monolayer reveals high grain mobility and large scale vortex flows coexistent with partial preservation of the global hexagonal lattice structure. The transport of particles is superdiffusive and ascribed to Lévy statistics on short time scales and to memory effects on the longer scales influenced by cooperative motion. At these longer time scales, the transport is governed by vortex flows covering a wide spectrum of temporal and spatial scales.

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Onset of turbulence and profile resilience in the Helimak configuration.

An experimental study of the onset of drift wave and flute interchange instabilities in the Helimak configuration is presented. It is shown that the Helimak offers the opportunity to separate the regions where these instabilities are active and to assess their relative role in cross-field anomalous transport and in the self-organization of exponential plasma density profiles with resilient scale length. Some results indicating a period doubling route to turbulence are also presented.

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Experimental determination of dust-particle charge in a discharge plasma at elevated pressures.

The charge of dust particles is determined experimentally in a bulk dc discharge plasma in the pressure range 20-100 Pa. The charge is obtained by two independent methods: one based on an analysis of the particle motion in a stable particle flow and another on an analysis of the transition of the flow to an unstable regime. Molecular-dynamics simulations of the particle charging for conditions similar to those of the experiment are also performed. The results of both experimental methods and the simulations demonstrate good agreement. The charge obtained is several times smaller than predicted by the collisionless orbital motion theory, and thus the results serve as an experimental indication that ion-neutral collisions significantly affect particle charging.

Journal Article↗