Dust surface potential in a generalized (r
, q
)-distributed multi-ion dusty plasma

AbstractDust charging processes involving the collection of electrons and positive/negative ions in a non-equilibrium dusty plasma are revisited by employing the power-law kappa (κ)-distribution function. In this context, the current balance equation is solved to obtain dust grain surface potential in the presence of negative ions. Numerically, it is found that plasma parameters, such as the κ spectral index, the negative ion-to-electron temperature ratio (γ), the negative–positive ion number density ratio (α), and the negative ion streaming speed (U0) significantly modify the dust grain potential profiles. In particular, for large kappa values, the dust grain surface potential reduces to the Maxwellian case, and at lower kappa values the magnitude of the negative dust surface potential increases. An increase in γ and U0 leads to the enhancement of the magnitude of the dust grain surface potential, while α leads to an opposite effect. The relevance of present results to low-temperature laboratory plasmas is discussed.

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Eﬀect of ion beam current on dust charge ﬂuctuations and ion-acoustic waves in electronegative dusty plasmas

Physica Scripta ◽

10.1088/1402-4896/ac3d4d ◽

2021 ◽

Author(s):

Suresh Basnet ◽

Anish Maskey ◽

Atit Deuja ◽

Raju Khanal

Keyword(s):

Surface Potential ◽

Ion Beam ◽

Beam Current ◽

Charge Fluctuations ◽

Dust Charge ◽

Positive Ions ◽

Ion Acoustic ◽

Dust Charge Fluctuations ◽

Ion Waves ◽

Dust Surface

Abstract The effects of ion beam current associated with the streaming positive ions on the dust charge fluctuations and ion acoustic wave propagation in quiescent electronegative dusty plasma have been investigated using fluid theory. The dust charging phenomenon and unstable mode of ion waves are modified for two streaming conditions of positive ions which are extended and graphically illustrated. The dependencies of the growing and damping rate of ion waves on dust density and the size of dust grains are studied. The evolution of dust surface potential is found in the negative domain with the increase in concentration of negative ions and the instability rate for ion wave decreases. Furthermore, it is shown that the dust surface potential shifts into positive domain as the electrons are significantly depleted (and the plasma becomes ion-ion plasma) from the electronegative plasma and thus ion waves exhibit a damping phenomenon.

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The calculation of grain charge in a dense dusty plasma with a nonuniform surface potential

Advances in Space Research ◽

10.1016/s0273-1177(02)00066-2 ◽

2002 ◽

Vol 29 (9) ◽

pp. 1277-1282 ◽

Cited By ~ 9

Author(s):

L. Bringol-Barge ◽

T.W. Hyde

Keyword(s):

Dusty Plasma ◽

Surface Potential ◽

Nonuniform Surface

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The effects of surface absorbed monolayer microdiffraction patterns

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100105461 ◽

1988 ◽

Vol 46 ◽

pp. 680-681

Author(s):

M. Pan ◽

J.M. Cowley

Keyword(s):

Surface Potential ◽

Electron Probe ◽

Potential Distribution ◽

Crystal Surface ◽

Normal Direction ◽

Surface Image ◽

Extended Surface ◽

Gas Molecules ◽

Surface Nature ◽

Electron Microdiffraction

Electron microdiffraction patterns, obtained when a small electron probe with diameter of 10-15 Å is directed to run parallel to and outside a flat crystal surface, are sensitive to the surface nature of the crystals. Dynamical diffraction calculations have shown that most of the experimental observations for a flat (100) face of a MgO crystal, such as the streaking of the central spot in the surface normal direction and (100)-type forbidden reflections etc., could be explained satisfactorily by assuming a modified image potential field outside the crystal surface. However the origin of this extended surface potential remains uncertain. A theoretical analysis by Howie et al suggests that the surface image potential should have a form different from above-mentioned image potential and also be smaller by several orders of magnitude. Nevertheless the surface potential distribution may in practice be modified in various ways, such as by the adsorption of a monolayer of gas molecules.

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