Dynamic Circulation in a Complex Plasma

Saitou, Yoshifumi; Ishihara, Osamu

doi:10.1103/physrevlett.111.185003

Cited by 27 publications

(26 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4,6,7 In some of the recent observations, the suspended dust medium is observed to be in complex dynamical states. For example, dust vortex is observed forming in laboratory dusty Plasmas 8,9 and in microgravity conditions in a dust cloud surrounding a void. 10 The experimental observations also motivated the modeling of dust vortex 11,12 and numerical simulations where the dust vortex are recovered 13 along with the signatures of a vortex flow turbulence.…”

Section: Introductionmentioning

confidence: 98%

Dynamics of a confined dusty fluid in a sheared ion flow

2014

View full text Add to dashboard Cite

Dynamics of an isothermally driven dust fluid is analyzed which is confined in an azimuthally symmetric cylindrical setup by an effective potential and is in equilibrium with an unconfined sheared flow of a streaming plasma. Cases are analyzed where the confining potential constitutes a barrier for the driven fluid, limiting its spatial extension and boundary velocity. The boundary effects entering the formulation are characterized by applying the appropriate boundary conditions and a range of solutions exhibiting single and multiple vortex are obtained. The equilibrium solutions considered in the cylindrical setup feature a transition from single to multiple vortex state of the driven flow. Effects of (i) the variation in dust viscosity, (ii) coupling between the driving and the driven fluid, and (iii) a friction determining the equilibrium dynamics of the driven system are characterized.

show abstract

Section: Introductionmentioning

confidence: 98%

Dynamics of a confined dusty fluid in a sheared ion flow

2014

View full text Add to dashboard Cite

show abstract

“…In some of these experiments, magnetic field was applied. [7][8][9][10][11][12][13] In presence of magnetic field, the electric field inside the plasma induces an azimuthal (E Â B) rotation of ions. It causes the levitated dust particles to rotate in azimuthal direction at low pressures.…”

Section: Introductionmentioning

confidence: 99%

Observation of dust torus with poloidal rotation in direct current glow discharge plasma

et al. 2015

View full text Add to dashboard Cite

Observation of dust cloud rotation in parallel-plate DC glow discharge plasma is reported here. The experiments are carried out at high pressures ($130 Pa) with a metallic ring placed on the lower electrode (cathode). The dust cloud rotates poloidally in the vertical plane near the cathode surface. This structure is continuous toroidally. Absence of magnetic field rules out the possibility of E Â B induced ion flow as the cause of dust rotation. The dust rotational structures exist even with water cooled cathode. Therefore, temperature gradient driven mechanisms, such as thermophoretic force, thermal creep flow, and free convection cannot be causing the observed dust rotation. Langmuir probe measurement reveals the existence of a sharp density gradient near the location of the rotating dust cloud. The gradient in the density, giving rise to a gradient in the ion drag force, has been identified as the principal cause behind the rotation of dust particles. V C 2015 AIP Publishing LLC. [http://dx.

show abstract

“…By adjusting the magnetic field strength it is possible to create plasma states where only the electrons, electrons and ions, or possibly all three charged particle species including the dust particles are magnetized [4]. Several new phenomena have been observed in experiments with magnetic fields, including a slow rotation of the entire dust cloud [5][6][7][8][9], the spinning of dust particles [10], and complicated flow patterns [11]. In recent experiments with strong magnetic fields on the order of a few Tesla, sufficient to magnetize not only the electrons but the ions as well, filaments appeared in the discharge [12].…”

mentioning

confidence: 99%

Streaming Complex Plasmas: Ion Susceptibility for a Partially Ionized Plasma in Parallel Electric and Magnetic Fields

Kählert

Joost

Ludwig

et al. 2016

Contrib. Plasma Phys.

View full text Add to dashboard Cite

The density response function for streaming ions in homogeneous, parallel electric and magnetic fields is derived self-consistently from kinetic theory. Ion-neutral collisions are treated with the Bhatnagar-GrossKrook collision operator assuming a constant ion-neutral collision frequency. The result accounts for the nonMaxwellian distribution function of the ions and is valid in the full range from weak to strong magnetization. It provides the basis for various linear response calculations in the context of magnetized complex plasmas, where streaming ions interact with highly charged dust particles under the influence of a strong external magnetic field. Magnetic fields play an important role in plasma physics because they allow one to confine and manipulate charged particles externally. Plasma properties such as wave spectra, particle diffusion, heat conduction, or plasma instabilities can be strongly modified when the plasma is magnetized. Strong magnetic fields of several Tesla are not only encountered in magnetic confinement or magnetic liner inertial fusion experiments [1] but have also become of interest for complex plasmas research [2,3]. By adjusting the magnetic field strength it is possible to create plasma states where only the electrons, electrons and ions, or possibly all three charged particle species including the dust particles are magnetized [4]. Several new phenomena have been observed in experiments with magnetic fields, including a slow rotation of the entire dust cloud [5][6][7][8][9], the spinning of dust particles [10], and complicated flow patterns [11]. In recent experiments with strong magnetic fields on the order of a few Tesla, sufficient to magnetize not only the electrons but the ions as well, filaments appeared in the discharge [12]. The dynamics of a dust particle pair also showed a pronounced response to magnetic fields of this magnitude [13]. Experiments performed at the Magnetized Dusty Plasma Experiment (MDPX) at Auburn University [14] further demonstrate that ordered structures of a titanium mesh can be imposed on the dust particles under these conditions. Crystalline and strongly coupled fluid states [15,16] also occur naturally in dusty plasmas due to the strong Coulomb interaction between the grains. Even though the dust particles themselves are difficult to magnetize [17], their screened interaction, and thus, their collective behavior, can be affected significantly by an external magnetic field [18].Dusty plasma experiments are often confronted with ion flows due to electric fields, especially in the sheath region. They affect the charging of the dust grains [19], their mutual interaction due to the formation of wake potentials [20,21], and give rise to drag forces [22,23]. Under the influence of an electric field the ion velocity distribution may considerably differ from a displaced Maxwellian due to collisions with the neutral gas. Various phenomena related to the interaction between ions and dust particles have been shown to be crucially affected by the different dist...

show abstract

Dynamic Circulation in a Complex Plasma

Cited by 27 publications

References 30 publications

Dynamics of a confined dusty fluid in a sheared ion flow

Dynamics of a confined dusty fluid in a sheared ion flow

Observation of dust torus with poloidal rotation in direct current glow discharge plasma

Streaming Complex Plasmas: Ion Susceptibility for a Partially Ionized Plasma in Parallel Electric and Magnetic Fields

Contact Info

Product

Resources

About