Nonlinear oscillations in dusty plasmas with variable charges on dust particles

2011

Our recent analysis on nonlinear nonextensive dust-acoustic waves (DA) [Amour and Tribeche in Phys. Plasmas 17:063702, 2010] is extended to include selfconsistent nonadiabatic grain charge fluctuation. The appropriate nonextensive electron charging current is rederived based on the orbit-limited motion theory. Our results reveal that the amplitude, strength and nature of the nonlinear DA waves (solitons and shocks) are extremely sensitive to the degree of ion nonextensivity. Stronger is the electron correlation, more important is the charge variation induced nonlinear wave damping. The anomalous dissipation effects may prevail over that dispersion as the electrons evolve far away from their Maxwellian equilibrium. Our investigation may be of wide relevance to astronomers and space scientists working on interstellar dusty plasmas where nonthermal distributions are turning out to be a very common and characteristic feature.

“…We assume that the variable charge dust component is a cold beam of particles, each particle having the same speed at a given position. Thus, we choose (Tribeche et al 2002)…”

Section: Theoretical Model and Basic Equationsmentioning

confidence: 99%

mentioning

confidence: 98%

Nonextensive dust acoustic waves in a charge varying dusty plasma

Bacha

2011

“…We assume that the variable charge dust component is a cold beam of particles, each particle having the same speed at a given position. Thus, we choose (Tribeche et al 2002) f d (x, v d …”

Section: Basic Equationsmentioning

confidence: 99%

Nonlinear dust acoustic waves in a charge varying complex plasma with nonthermal ions featuring Tsallis distribution

Benzekka

2011

The concept of ion nonthermality is generalized within the theoretical framework of the Tsallis thermostatistics. In this connection, a physically meaningful ion distribution function is outlined. As the nonextensive character of the nonthermal ions increases, the distribution shoulders may become less or more prominent and high energy states are less or more probable than in the extensive nonthermal case. Variable charge dust acoustic waves are then addressed. We first consider the case of adiabatic dust charge variation and discuss later the case when the nonadiabatic charge variations are self-consistently included. Our results may complement and provide new insight into previously published work in nonthermal space plasmas.

“…Let us then look at a simple case, in which the dust component is a cold beam of particles, each particle having the same speed at a given position. Thus, we choose (Tribeche et al 2002) f d (x, v d …”

Section: Variable Dust Charge Casementioning

confidence: 99%

Nonlinear dust acoustic waves in electronegative dusty plasmas

Benzekka

2010

The problem of nonlinear localized dust acoustic (DA) is addressed in a plasma comprising positive ions, negative ions, and mobile negatively charged dust grains. We first consider the case when the grain charge remains constant and discuss later the case when the charge variations are self-consistently included. It is found that a relative increase of the positive ion density favors the propagation of the DA solitary waves, in the sense that the domain of their admissible Mach numbers enlarges. Furthermore, electronegativity makes the dust acoustic solitary structure more spiky. When the dust grain charge Q d is allowed to fluctuate, the latter is expressed in terms of the Lambert function and we take advantage of this transcendental function to investigate the variable charge DA solitary wave. Q d adopts a localized profile and becomes more negative as the number of charges Z (−) of the negative ion increases. The dust grains are found to be highly localized. This localization (accumulation) caused by a balance of the electrostatic forces acting on the dust grains becomes more effective for lower values of Z (−) . An increase of Z (−) may lead to a local depletion of the negative ions from the region of the soliton's localization. The results are useful to understand the salient features of localization of large amplitude dust acoustic waves in cosmic plasmas such as the ionospheric D-region and the mesosphere.