Parametric instabilities in magnetized multicomponent plasmas.

This paper investigates the excitation of various natural modes in a magnetized bi-ion or dusty plasma. The excitation is provided by parametrically pumping the magnetic field. Here two ionlike species are allowed to be fully mobile. This generalizes our previous work where the second heavy species was taken to be stationary. Their collection of charge from the background neutral plasma modifies the dispersion properties of the pump and excited waves. The introduction of an extra mobile species adds extra modes to both these types of waves. We first investigate the pump wave in detail, in the case where the background magnetic field is perpendicular to the direction of propagation of the pump wave. Then we derive the dispersion equation relating the pump to the excited wave for modes propagating parallel to the background magnetic field. It is found that there are a total of twelve resonant interactions allowed, whose various growth rates are calculated and discussed.

Rotational modes of oscillation of rodlike dust grains in a plasma.

Three dimensional rotatory modes of oscillations in a one-dimensional chain of rodlike charged particles or dust grains in a plasma are investigated. The dispersion characteristics of the modes are analyzed. The stability of different equilibrium orientations of the rods, phase transitions between the different equilibria, and a critical dependence on the relative strength of the confining potential are analyzed. The relations of these processes with liquid crystals, nanotubing, and plasma coating are discussed.

Kinetics of plasma flowing around two stationary dust grains.

The characteristics of plasma particle kinetics in the presence of ions flowing around two stationary dust grains aligned in the direction of the flow are studied using a three-dimensional molecular dynamics simulation code. The dynamics of plasma electrons and ions as well as the charging process of the dust grain are simulated self-consistently. Distributions of electron and ion number densities, and the electrostatic plasma potential are obtained for various intergrain distances, including those much less, of the order of, and more than the plasma electron Debye length.

Self-excited vertical oscillations in an rf-discharge dusty plasma.

A self-excited vertical oscillation of dust grains in the sheath region of an rf-discharge plasma has been observed. The variation of amplitude with pressure and input power was measured. Dramatic increase of oscillation amplitude was found for pressures below 4.5 Pa. Possible excitation mechanisms are considered.

Dynamics of the charging and motion of a macroparticle in a plasma flow.

The dynamics of motion and charging of a macroscopic "dust" particle in a plasma with an ion flow is investigated by employing the particle-in-cell method. It is demonstrated that the charging and motion of the dust particle levitating in an external parabolic potential is related to the ion flow. This situation is relevant for the majority of experiments on the self-organization and crystallization of colloidal dust grains in a low-temperature plasma.

Plasma kinetics around a dust grain in an ion flow.

The kinetics of plasma particles around a stationary dust grain in the presence of an ion flow is studied using a three-dimensional molecular dynamics simulation method. The model is self-consistent, involving the dynamics of plasma electrons and ions as well as charging of the dust grain. The effect of ion focusing is investigated as a function of the ion flow velocity. Distributions of electron and ion number densities, and electrostatic plasma potential are obtained.

Effect of a dipole moment on the wake potential of a dust grain in a flowing plasma.

The effect of a dipole moment on the wake potential of a dust grain in a collisionless plasma with a supersonic ion flow is studied. It is found that both the point charge and the dipole moment can be responsible for the oscillatory potential behind the dust. The dipole moment is dominant in forming the wake potential when the dipole moment p becomes of the order of the absolute value (Q) lambda(D), where Q is the dust charge and lambda(D) is the Debye length.

Equilibrium and oscillations of grains in the dust-plasma crystal.

The dispersion characteristics of the low-frequency mode associated with vertical oscillations of dust grains in a quasi-two-dimensional dust-plasma crystal are calculated, taking into account the dependence of the dust charge on the local sheath potential. It is shown that the equilibrium of the dust grains close to the electrode may be disrupted by large amplitude vertical oscillations.