Dynamics of the ordered structure formation in a thermal dusty plasma (original) (raw)

Dusty plasmas: synthesis, structure and dynamics of a dust cloud in a plasma

The European Physical Journal Applied Physics, 2010

Plasmas are energetic media that can give birth to dust particles due to the presence of reactive gases or plasma-surface interactions. Industrial plasmas are often concerned by these dust particles that can be either unwanted or useful for the process. For fusion plasmas, production of dust particles from wall erosion is a serious issue for performance and safety reasons. In this article, some aspects of dusty plasmas with potential implications for plasma experimenters will be discussed. Convenient ways for detecting the presence or the growth of dust particles will be presented. The spatial distribution of the dust cloud during the plasma phase determines the subsequent dust particle deposition. It will be shown that some reactor regions can attract or repeal these dust particles. Finally, the dust particle dynamics after the plasma extinction will be investigated. A special attention will be paid on the residual electric charge that can stay attached on the dust particle surface and on its implications for dust particle control or deposition.

Kinetic Description of Dusty Plasmas and Problems of Grain Dynamics

Contributions to Plasma Physics, 2001

Basic principles of kinetic theory of dusty plasmas are formulated with regard for electron and ion absorption by dust particles. Rigorous microscopic equations are derived and employed to introduce the BBGKY-hierarchy and kinetic equations.

Numerical simulations of interactions of warm plasmas and a dust-grain

Results from numerical simulations of the interaction between a warm plasma and individual dust particles are reported. The analysis is carried out in two spatial dimensions, using a particle-in-cell (PIC) numerical code, considering conducting as well as insulating materials for the dust. For macroscopic dust particles in streaming plasmas, we observe the development of an electric dipole moment associated with the particles. The strength of this dipole moment is very different for conducting and insulating materials, and its direction is opposite for the two cases. For supersonic flows we note the formation of a Mach-cone, with properties in agreement with analytical results, in particular also concerning the effects of Landau damping.

Ordering of dust particles in dusty plasmas under microgravity

Physical Review E, 2005

Structure formation of dust particles in dusty plasmas under microgravity has been simulated by the molecular dynamics method. It is shown that, at low temperatures, dust particles are organized into layered spherical shells. The number of shells is a function of the system size and the strength of screening by ambient plasma particles, while the dependency on the latter is much weaker. In the simulation, the condition of the charge neutrality satisfied by the system of dust particles and plasma particles is properly taken into account.

Dusty Plasmas: Elementary Processes, Examples and Possible Applications

This work presents an up-to-date account in dusty plasmas, a new field of current research's interest in applied physics and modern technology. These are complex systems containing nanometer or micrometer-sized particles suspended in plasma. Dust particles may be charged and the plasma and particles behave as plasma, following electromagnetic laws for particle up to about 10 nm or 100 nm if large charges are present. Dusty plasmas are interesting because presence of particles significantly alters the charged particle equilibrium leading to different phenomena. Electrostatic coupling between the grains can vary over a wide range so that the states of the dusty plasma can change from weakly coupled to crystalline. Such plasmas are of interest as a non-Hamiltonian system of interacting particles and as a means to study charging of dust particles in plasmas, electrostatic potential around a dust particle main forces acting on dust particles in plasmas, interaction between dust particles in plasmas, formation and growth of dust particles.

Dynamic behaviors of dust particles in the plasma–sheath boundary

Physics of Plasmas, 2001

A variety of dynamic behaviors in dusty plasmas is expected under the experimental condition of weak friction with gas molecules. The device ''KAGEROU'' provides such an environment for dynamic collective phenomena. Self-excited dust oscillations in Coulomb crystals have been observed at low values of plasma density and gas pressure. An instability mechanism was identified to be delayed charging in an inhomogeneous equilibrium dust charge in the sheath. The theoretical growth rate was formulated in relation to the destabilization of a transverse dust lattice wave ͑T-DLW͒, which was found to be very sensitive to the presence of a small amount of hot electrons which produces a substantial positive equilibrium charge gradient ٌQ d-eq around the equilibrium position of dust particles in the plasma-sheath boundary. The first experimental observation of a correlated self-excited vertical oscillations in a one-dimensional dust chain indicates a destabilization of T-DLW. The experimental condition is very consistent with the parameter area which predicts numerically an instability of T-DLW.

Dust particles in low-pressure plasmas: Formation and induced phenomena

Pure and Applied Chemistry, 2000

Formation of dust particles is a common mechanism in low-pressure plasmas. These big particles (in comparison with other plasma species) are sometimes the desired final products of the process, but they may also constitute a severe drawback in certain contexts. In either situation, it is necessary to understand growth mechanisms well, in order to control or avoid dust particle formation. One of the problems that has to be overcome is that dust particle growth is usually a continuous mechanism: once started, it can enter into a cyclic regime where new generations of dust particles are succeeding one after the other. This cyclic phenomenon often induces a side effect consisting of instabilities of a few tens of Hz. This paper discusses the main characteristics of dust successive generations, and particularly the importance of dust-free spaces (void) involved in this process. Finally, some aspects related to deposition when several generations coexist will be presented. Fig. 4 Spectrogram of Fig. 3 around the second and third dust particle generations. It underlines that an oscillating pattern of a few tens of Hz is superimposed on the continuous signal variation. Two alternating regimes can be identified, HOR and LOR. M. MIKIKIAN et al.

Dynamics of Dust Aggregates in a Complex Plasma

2012

Dust aggregates in complex plasmas have been studied theoretically in computer models, but not extensively in an experimental setting. This work investigates several properties of aggregates which are responsible for dust dynamics: charge, dipole moment, and gas drag. A diode pumped laser is used to perturb aggregates in a GEC rf reference cell, and a high-speed camera acquires image data. Particle trajectories are extracted and analyzed to characterize or estimate values of the properties under investigation.

Stationary Velocity and Charge Distributions of Grains in Dusty Plasmas

Physical Review Letters, 2000

Within the kinetic approach velocity and charge distributions of grains in stationary dusty plasmas are calculated and the relations between the effective temperatures of such distributions and plasma parameters are established. It is found that the effective temperature which determines the velocity grain distribution could be anomalously large due to the action of accelerating ionic bombarding force. The possibility to apply the results obtained to the explanation of the increasing grain temperature in the course of the Coulomb-crystal melting by reduction of the gas pressure is discussed. This paper was received by Phys.Rev.Lett. on 11 August 1999. As potential referees the authors offered to Editor the following persons: V.N.