Plasma Crystal in (3 + 1) Dimensions

JETP Letters - A quasi-two-dimensional plasma crystal in (3 + 1) dimensions has been experimentally observed for the first time; i.e., three spatial coordinates of each microparticles of the...     

Pade spectroscopy of structural correlation functions: Application to liquid gallium

We propose the new method of fluid structure investigation based on numerical analytic continuation of structural correlation functions with Pade approximants. The method particularly allows extracting hidden structural features of disordered condensed matter systems from experimental diffraction data. The method has been applied to investigate the local order of liquid gallium, which has a non-trivial structure in both the liquid and solid states. Processing the correlation functions obtained from molecular dynamic simulations, we show the method proposed reveals non-trivial structural features of liquid gallium such as the spectrum of length-scales and the existence of different types of local clusters in the liquid.     

Electric potential around an absorbing body in plasmas: effect of ion-neutral collisions

A simple linear kinetic model is used to investigate the combined effect of plasma absorption and ion-neutral collisions on the electric potential around a small absorbing body in weakly ionized plasmas. It is demonstrated that far from the body the potential decays considerably slower than the conventional Debye-Hückel potential. Moreover, at distances exceeding approximately the ion mean free path, the potential approaches an unscreened Coulomb-like asymptote. Some important consequences of this result are discussed in the context of complex (dusty) plasmas.     

Complex plasma in narrow channels: Impact of confinement on the local order

Two-dimensional equilibrium configurations of the dust component of a complex plasma in narrow channels have been numerically simulated by the molecular dynamics method for various forms of the confinement potential such as the parabolic potential and potential well. The interaction between the charged dust particles is described by a screened Coulomb potential with allowance for the interaction of microparticles with a neutral gas. It has been shown that the form of the confinement potential strongly affects the local order of the microparticles in such a system.     

Highly resolved fluid flows: "liquid plasmas" at the kinetic level

Fluid flow around an obstacle was observed at the kinetic (individual particle) level using "complex (dusty) plasmas" in their liquid state. These "liquid plasmas" have bulk properties similar to water (e.g., viscosity), and a comparison in terms of similarity parameters suggests that they can provide a unique tool to model classical fluids. This allows us to study "nanofluidics" at the most elementary-the particle-level, including the transition from fluid behavior to purely kinetic transport. In this (first) experimental investigation we describe the kinetic flow topology, discuss our observations in terms of fluid theories, and follow this up with numerical simulations.     

On the interaction of microparticles with ion flux in gas discharge plasma

The charging and interaction of microparticles in the gas discharge near-electrode region, where the role of the external electric field and ion drift is significant, are considered. It is shown that the ion focusing, responsible for, as is generally accepted, the formation of vertical linear dust structures, is strongly suppressed under conditions typical of experiments with dusty plasma (i.e., the gas discharge at pressures of 10–100 Pa). The contribution of ions trapped by an ion microparticle to the dusty particle charge is estimated. It is shown that trapped ions can appreciably reduce the microparticle charge.     

Destruction of the ozone layer as a result of a meteoroid falling into the ocean

The falling of a large celestial body into the ocean causes a large number of compounds (for example, HCl, Cl, Br, Na, H₂O, OH, and NO) that destroy ozone molecules directly or indirectly to be ejected to stratospheric altitudes. The bleaching of the atmosphere in the UV range as a result of such ozone destruction creates negative feedback that restores the ozone. The characteristic time for such restoration in the stratosphere decreases sharply with altitude, ranging from several months at 30 km to several days at 20 km. Pis’ma Zh. éksp. Teor. Fiz. 70, No. 5, 360–366 (10 September 1999)     

Dust particle charging and formation of dust structures in the upper atmosphere

We investigate the dust particle charging process in the Earth’s upper atmosphere. Calculating the spectra of solar radiation, we study the influence of the photoelectric effect on the charging process. We show that both positively and negatively charged dust particles are present in the upper atmosphere. We consider the mechanisms which can be responsible for the formation of dust structures like noctilucent clouds and polar mesosphere summer echoes.