Diagnostics of the Electronegative Plasma Sheath at Low Pressures Using Microparticles

Annaratone, B. M.; Antonova, T.; Thomas, Hubertus M.; Morfill, G. E.

doi:10.1103/physrevlett.93.185001

Cited by 48 publications

(36 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is now known that electronegative plasmas are not pure in general, but are contaminated (in most cases) by dust (solid impurities). The dust (solid impurities) are not practically neutral, but are charged (Shukla and Eliasson 2009) by absorbing electrons, positive as well as negative ions Rosenberg and Merlino 2007;Kim and Merlino 2006;Merlino and Kim 2006;Annaratone and Allen 2005;Annaratone et al 2004;D'Angelo 2004;Mamun and Shukla 2003). Therefore, the electronegative plasmas are also called dirty or dusty electronegative plasma Rosenberg and Merlino 2007;Kim and Merlino 2006;Merlino and Kim 2006;Annaratone and Allen 2005;Annaratone et al 2004;D'Angelo 2004;Mamun and Shukla 2003).…”

Section: ; Franklin 2002mentioning

confidence: 97%

Dust-ion-acoustic solitary waves and their multi-dimensional instability in a magnetized dusty electronegative plasma with trapped negative ions

Rahman

Mamun

Ashrafi

2011

Astrophys Space Sci

View full text Add to dashboard Cite

A theoretical investigation has been made on obliquely propagating dust-ion-acoustic solitary waves (DIASWs) in magnetized dusty electronegative plasma containing Boltzmann electrons, trapped negative ions, cold mobile positive ions, and arbitrarily charged stationary dust. The reductive perturbation method has been employed to derive the modified Zakharov-Kuznetsov (MZK) equation which admits solitary wave solution under certain conditions. The multi-dimensional instability of these solitary waves is also studied by the small-k (long wavelength plane wave) perturbation-expansion technique. The basic properties (speed, amplitude, width, instability, etc.) of small but finite amplitude DIASWs are significantly modified by the effects of external magnetic field, obliqueness, polarity of dust, and trapped negative ions. The implications of our results in space and laboratory plasmas are briefly discussed.

show abstract

Section: ; Franklin 2002mentioning

confidence: 97%

Dust-ion-acoustic solitary waves and their multi-dimensional instability in a magnetized dusty electronegative plasma with trapped negative ions

Rahman

Mamun

Ashrafi

2011

Astrophys Space Sci

View full text Add to dashboard Cite

show abstract

“…This correlation analysis of the dust equilibrium position combined with the spatial electric field profile is applicable as a diagnostic tool to estimate plasma parameters, i.e. the dust particles can serve as electrostatic probes [38,39,[92][93][94]. The correlation analysis yields the maximum sheath extension as the only free fitting parameter, which depends on electron temperature and density (s max,p ∝ λ De /T ).…”

Section: Adiabatic Phase Changementioning

confidence: 99%

“…In all cases the manipulation of dust particles, which is realized by controlling forces exerted on them such as electrostatic, thermophoretic, ion drag, and gravitational forces, or externally applied ones, e.g., created by a laser beam [34][35][36][37], is crucially important. Furthermore, the use of dust particles as probes of these forces revealing plasma properties is a current topic of research [38,39].…”

Section: Introductionmentioning

confidence: 99%

Transport control of dust particles via the electrical asymmetry effect: experiment, simulation and modelling

Iwashita¹,

Schüngel²,

Schulze³

et al. 2013

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

Abstract.The control of the spatial distribution of micrometer-sized dust particles in capacitively coupled radio frequency discharges is relevant for research and applications. Typically, dust particles in plasmas form a layer located at the sheath edge adjacent to the bottom electrode. Here, a method of manipulating this distribution by the application of a specific excitation waveform, i.e. two consecutive harmonics, is discussed. Tuning the phase angle θ between the two harmonics allows to adjust the discharge symmetry via the Electrical Asymmetry Effect (EAE). An adiabatic (continuous) phase shift leaves the dust particles at an equilibrium position close to the lower sheath edge. Their levitation can be correlated with the electric field profile. By applying an abrupt phase shift the dust particles are transported between both sheaths through the plasma bulk and partially reside at an equilibium position close to the upper sheath edge. Hence, the potential profile in the bulk region is probed by the dust particles providing indirect information on plasma properties. The respective motion is understood by an analytical model, showing both the limitations and possible ways of optimizing this sheath-to-sheath transport. A classification of the transport depending on the change in the dc self bias is provided, and the pressure dependence is discussed.

show abstract

“…Recently, there is a growing interest in the boundary layer structures of multicomponent plasmas, [11][12][13][14][15][16] including complex ͑dusty͒ plasmas [13][14][15] and electronegative plasmas, 16 since the regions are sensitive to plasma-surface interactions. In plasma etching and deposition, for instance, the contamination problem caused by the charged dust has always been a major concern.…”

Section: Introductionmentioning

confidence: 99%

Presheath structure of a dust-contaminated plasma

2006

Physics of Plasmas

View full text Add to dashboard Cite

The presheath structure of a dust-contaminated plasma is studied by taking into account the electron-impact ionization, the plasma loss due to the capture of electrons and ions by the dust grains, the ion-dust collisions, as well as the dust charge variations. It is shown that at the edge of the presheath with the sheath, there is a critical ion Mach number (the generalized Bohm criterion modified by the dust) which is exactly the same as that obtained from collisionless sheath model. On the other hand, depending on different equilibrium states of the bulk plasma, different connections between the bulk plasma and the presheath will be inferred. When the electron-impact ionization exactly balances the plasma loss, there is a smooth transition from the bulk plasma to the presheath, and both the ion velocity and the gradients of the velocity and density vanish at the edge of the presheath with the bulk plasma. When the plasma loss exceeds the ionization, the presheath starts at the point where the ion velocity equals the ambipolar diffusion velocity, i.e., the presheath profile is connected to the diffusion profile of the bulk plasma. When the ionization exceeds the plasma loss, the bulk plasma-presheath edge appears where the gradient of the ion density is zero but the gradient of the ion velocity is nonzero. For the plasma loss exceeding or being less than the ionization, numerical results reveal that the change of the dust density can result in opposite effects on the presheath profiles (shortening or broadening of the presheath region).

show abstract

Diagnostics of the Electronegative Plasma Sheath at Low Pressures Using Microparticles

Cited by 48 publications

References 14 publications

Dust-ion-acoustic solitary waves and their multi-dimensional instability in a magnetized dusty electronegative plasma with trapped negative ions

Dust-ion-acoustic solitary waves and their multi-dimensional instability in a magnetized dusty electronegative plasma with trapped negative ions

Transport control of dust particles via the electrical asymmetry effect: experiment, simulation and modelling

Presheath structure of a dust-contaminated plasma

Contact Info

Product

Resources

About