Shock wave formation in a dc glow discharge dusty plasma.

A jump of dust density propagating through the dusty plasma structure has been observed. To excite the disturbance an impulse of axial magnetic field to the dusty plasma in a dc glow discharge striation has been applied. This impulse resulted in the dynamical stretching of the dusty plasma structure. During the reconstruction of the structure a ramp-shaped perturbation of dust density appeared. The perturbation was steepening and formed into a dust-acoustic shock. The anomalously high shock compression is observed.

Large-amplitude dust waves excited by the gas-dynamic impact in a dc glow discharge plasma.

A large-amplitude wave with two humps of dust density, separated by a dip was generated. To excite the wave in the dc glow discharge dusty plasma a gas-dynamic impact was used. The structure obtained had several interesting properties such as strong compression of dust in the humps, supersonic dust particles in the rarefaction zone, reconstruction of the initial dust configuration after the passing of the wave. The peculiarities of the phenomenon observed are discussed. The mechanism of generation and propagation for such kind of perturbation is proposed.

Transport of microparticles in weakly ionized gas-discharge plasmas under microgravity conditions.

Measurements of effective structural (pair correlation function) and transport (diffusion constant) characteristics of the system of microparticles in dc and rf gas-discharge plasmas under microgravity conditions are reported. The comparison between these measurements and numerical simulations is used for complex plasma diagnostics.

Dependence of the dust-particle charge on its size in a glow-discharge plasma.

Measurements of the charge of dust grains have been performed in a quasineutral plasma over a wide range of grain sizes. A new method was established for measuring the charge on grains levitating in the striations of a dc glow discharge. A single dust particle is moved out of a dust cloud with the help of a focused laser beam. When it leaves the beam it returns back to the cloud, and the charge on the grain is derived from the analysis of the returning trajectory. The obtained dependence of the dust-grain charge on its size was found to be strongly nonlinear in the experimental conditions.