The Dust Charging Processes And Dust Acoustic Waves In The Nonequilibrium Dusty Plasma With Power-law Distribution

Dusty plasmas, which can be loosely defined as normal electron-ion plasmaswith additional charged components of dust grains, are rather ubiquitous in space andlaboratory. According to the theoretical analyses and space observations, it should bepointed out that suprathermal particles in the dusty plasma obey the power-lawdistribution instead of the Maxwell distribution, and moreover, the space plasmas aregenerally in motion and thus an permeating plasma physical phenomenon mayfrequently occur if two or more space plasmas encounter in the same space region.Consequently, the theoretical achievements in the dusty plasmas is generalized in theframework of nonextensive statistics, additionally, the dust-acoustic waves is studiedin the interpenetrating dusty plasma.Firstly, some elemental dust charging processes in the dusty plasma isinvestigated on the basis of nonextensive statistics, including the collection of plasmaparticles and the secondary electron emission induced by the impact of electrons. Theelectrons and ions are assumed to be described by the nonextensive power-lawdistribution with q-parameters different from each other. Therefore, the dust chargingcurrents, including electron current, ion current and secondary electron current arederived. For different dust charging processes, according to the theoretical analysisand numerical calculation, the influnce of the electrons’ and ions’ nonextensivecharacters on the dust charge is analyzed.Then, the nonextensive statistics is applied to study the nonlinear properties ofdust-acoustic solitary waves in the dusty plasmas. The investigation is based on twodifferent assumptions. The dust charge is either unvariable or variable. If the dustcharge is kept constant, according to the reductive erturbation method and theSagdeev potential method, the dust-acoustic solitary solution with small amplitudeand arbitary amplitude are derived. The influnces of the nonextensive parameters onthe solitary waves are identical by analysis. Therefore, if the dust charge is variable,only the small-amplitude dust-acoustic solitary waves are studied. With these twodifferent assumptions, the nonextensive characters have different effects on thesolitary waves. The nonextensive character of electrons affects on the dust chargefluctuation and thus affects on the solitary waves indirectly, on the other hand, thenonextensive character of ions affects on the solitary waves directly.At last, the model of the permeating dusty plasma is established, which consists of two parts, i.e., the fast flowing dusty plasma and the target dusty plasma. In theframeworks of the classical and nonextensive statistics, the dust-acoustic waves andtheir stability in the permeating dusty plasma are investigated. It has been found thatthe stability of the waves depends strongly on the velocity of the fast flowing dustyplasma. There are two limiting physical cases that the thermal velocity of the flowingdusty plasma is much larger than or much smaller than the phase velocity of thewaves. In the former case, the dust acoustic waves are always instable, while in thelatter case, the dust acoustic waves may be stable and the stability is affected by thecharacters and nonextensive parameters of some components.