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An effective anisotropic potential is proposed for the interaction between dust particles in a gas‐discharge plasma. In addition to the Coulomb repulsion this potential takes into account attraction due to the spatial positive plasma charge originating from focusing of the ionic fluxes by dusty particles. The time evolution of the dust particle kinetic and potential energies from random initial configurations have been investigated by the Brownian dynamics method. Results of our simulation showed that the attraction between dusty particles can be the main physical reason of formation and decay of classical bound dust particle pairs and many particle complexes with low potential energy, while the kinetic energy (temperature) of unbound dust particles and particle oscillating in bound complexes may increase on three order as observed in experiments.

The results are given of an experimental investigation of processes of heat transfer for fluid dust structures in rf‐discharge. The analysis of steady‐ state, and unsteady‐state heat transfer are used to obtain the thermal conductivity, and diffusivity constants.

In this work we have developed and applied the technique that allowed us measuring thermal capacity, conductivity and diffusivity coefficients of dusty plasma liquid. Thermal capacity dependence on non‐ideality in the system concerned was also measured experimentally.

The convection of dust particle in a plasma is related to the spatial gradients of dust charge distributions existing due to different plasma conditions in different parts of dusty structures. Here, the set of nonlinear equations is derived suitable for study of the basic stationary dust structures as well as their convective perturbations. On its basis, the stationary nonlinear states of self‐organized cylindrical dusty structures in a plasma as well as the realted convective cells are investigated. It is demonstrated that there is the broad range of plasma and dust parameters where the self‐organized dust convection exist.

Flows, shear flows, laminar and turbulent flows on the microscopic scales are one of the fundamental issues in fluid dynamics. Due to their special properties, complex plasmas provide an excellent opportunity to study these flows, even on the scale of individual particles. To this end, experiments were conducted in the ‘Plasmakristall 4’ (PK‐4) experimental device that uses the positive column of a high voltage DC discharge to produce complex (dusty) plasmas. The linear geometry of PK‐4 provides the opportunity to study all these kinds of flow phenomena as well as waves and collisions. Since gravity distorts most of the effects to be studied with PK‐4, the facility is planned to be operated onboard the International Space Station ISS from 2008. In order to generate a high‐velocity shear flow PK‐4 is now upgraded with a 20W manipulation laser system.

Complex plasmas are an ideal model system to investigate laminar fluids as they allow to study fluids at the kinetic level. At this level we are able to identify streamlines particle by particle. This gives us the ability to research the behaviour of these streamlines as well as the behaviour of each individual particle of the streamline.We carried out our experiments in a modified GEC‐RF‐Reference cell. We trapped the particles within two glass rings and forced them to form a circular flow by using several stripe electrodes. In this flow the particles behave like an ideal fluid and form streamlines. By putting an obstacle into the flow we reduce the cross‐section. To pass through this constricted cross‐section some streamlines have to reconnect. After the obstacle the streamlines split up again. An analysis how streamlines split up and reconnect as result of external pressure on the fluid in our system is presented here.Streamlines also occur if two clouds of particles penetrate each other. We call this ...

The ion drag force acting on dust particles in the positive column of a dc discharge is measured in the pressure range 20–120 Pa. The force is obtained by a method which does not require an a priori knowledge of the particle charge but uses the charge gradient determined from the same experiment. The method depends only on two experimentally determined quantities: the particle drift velocity and the electric field. The comparison of experimental results with theoretical models is presented and discussed.

An experimental determination of grain charge in a bulk dc discharge plasma covering a wide range of neutral gas pressures is reported. The measurements are compared with molecular dynamics simulations of charging and with a simple analytical model accounting for ion‐neutral collisions. All the considered evidence indicates that ion‐neutral collisions represent a very important factor, which significantly affects (reduces) the grain charge under typical discharge conditions.

Phenomenological criteria for various phase transitions in the Yukawa system are considered including the melting of cubic lattices and the transitions between the bcc‐ and fcc‐structures.

In this paper we present the first observations on dust particles growth and behavior under microgravity conditions obtained in the PKE‐Nefedov chamber by a French‐German‐Russian program. These experiments have been performed on board of the International Space Station (ISS) in late october by a French‐Russian cosmonauts team. Some of the results are discussed and compared with on ground experiments.