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- ItemExcitation of dipole oscillons in a dusty plasma containing elongated dust rods([London] : IOP, 2003) Salimullah, M.; Shukla, P.K.; Sandberg, I.; Morfill, G E.The dispersion properties and excitation mechanisms of 'dipole oscillons' in a dusty plasma containing charged elongated rod-like dust grains are investigated in the presence of streaming plasma particles for cases without and with an external static magnetic field. In a magnetized dusty plasma, a new 'oscillon-ion lower-hybrid' mode is found, which can be excited by the equilibrium energy of cross-field drifting ions.
- ItemDust-acoustic modes in plasmas with dust distributions and charge fluctuations([London] : IOP, 2003) Verheest, Frank; Jacobs, Gerald; Cattaert, TomCharge fluctuations in dusty plasmas are discussed starting from charge, mass, momentum and current equations for the combined dusty plasma. This allows a generic description of low-frequency waves in plasmas with dust distributions, and leads to the damping and other modifications of the dustacoustic and related modes, like generalized dust-Coulomb modes.
- ItemControlled interactions of two microparticle clouds in a dc glow discharge dusty (complex) plasma([London] : IOP, 2003) Thomas, E.The control of the confinement of charged microparticles in a plasma is an important topic for the dusty plasma community. Earlier experiments have used control over individual microparticles or a single particle cloud to obtain information about the potential structure of the surrounding plasma. In this paper, experiments that make use of active control of two microparticle clouds suspended in a plasma are discussed. Here, an array of three electrodes is used to modify the potential between the two clouds. Through the application of an applied perturbation on one of the array elements, the two clouds are allowed to interact. Particle image velocimetry techniques are used to obtain spatial maps of the interaction process. The experimental measurements show that an apparent recoil occurs between the two particle clouds as a result of the interaction. A simple model is used to show that a recoil may be a possible outcome of the interaction process.
- ItemSelf-excited motions in dusty plasmas with gradient of charge of macroparticles([London] : IOP, 2003) Vaulina, O. S.; Samarian, A. A.; Petrov, O. F.; James, B. W.; Fortov, V. E.Various self-excited motions in dusty plasmas involving spatial variations of macroparticle charge are considered. Two basic types of instabilities in these systems are examined numerically and analytically. The main attention is given to the vortex motions of macroparticles. Conditions suitable for creating the instabilities examined are discussed. Experimental observations of self-excited oscillations in dc-glow, and capacitive rf, discharges are presented. It is shown that spatial variation of dust charge can account for many phenomena observed in inhomogeneous laboratory dusty plasmas.
- ItemSolitons, shocks and vortices in dusty plasmas([London] : IOP, 2003) Shukla, P. K.; Mamun, A. A.Three important classes of nonlinear phenomena, namely solitons, shocks and vortices in dusty plasmas, have been discussed. The static and mobile charged dust grains have been considered in order to study all of these nonlinear phenomena. The effects of nonplanar geometry, dust grain charge fluctuations, dust fluid temperature, vortex-like ion distribution, strong dust correlation etc on the properties of dust ion-acoustic/dust-acoustic solitons have also been analysed. The implications of these theoretical investigations in experimental observations of soliton and shock formation in dusty plasmas are briefly discussed.
- ItemNew microscopic and macroscopic variables in dusty plasmas([London] : IOP, 2003) Schram, P. P. J. M.; Trigger, S. A.; Zagorodny, A. G.The kinetic theory of dusty plasmas, in which the absorption of electrons and ions by dust particles is the dominating interaction process, is derived from first principles. The charging process is shown to imply a considerable modification of properties in comparison with usual plasmas. Not only the electric charge, but also the mass, the angular momentum and the inner energy of the dust particles are new dynamic variables. Their influence on the kinetic behaviour of dusty plasmas is also considered.
- ItemInstability of shear waves in a nonuniform dusty plasma([London] : IOP, 2003) Sorasio, G.; Shukla, P. K.; Resendes, D. P.It is shown that shear waves in a strongly coupled dusty plasma with nonuniform plasma pressure and dust density can be destabilized. The dispersion relation as well as the instability condition have been found and investigated in detail.
- ItemModelling of two differently sized dust species in plasmas under micro-gravity([London] : IOP, 2003) Akdim, M. R.; Goedheer, W. J.; Dahiya, R. P.A self-consistent two-dimensional hydrodynamic model for a dusty argon plasma has been developed to model more than one dust species. Results are presented for situations where dust particles with two different diameters have been included. The final steady state solution is achieved after three injection steps of the dust particles. At every injection phase dust particles of only one size are let in and the simulation is continued until the steady state solution is achieved. Results show that the differently sized dust particles form crystals at different positions. These dust clouds have an influence on each other by means of positive space charge layers created due to the argon ions, which cannot match the steep dust crystal boundaries. The screened Coulomb interaction between the two differently sized dust species is neglected. The electric potential, ion density, electron density and electron energy show significant changes after each injection phase, even at an amount of dust that is small compared to that studied during the micro-gravity experiments.