Numerical simulations of dust charging and wakefield effects

Miloch, W. J.

doi:10.1017/s0022377814000300

Cited by 13 publications

(13 citation statements)

References 34 publications

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“…With the change in dominant ion species, the spacecraft can be supersonic at low altitudes, and subsonic at high altitudes. In both cases, a wake will form downstream of the spacecraft, which for supersonic flows can extend much farther than the Debye length from the spacecraft surface (Al'pert et al, 1966;Khrapak et al, 2005;Ludwig et al, 2012;Miloch, 2014;Darian et al, 2017;Paulsson et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

Electron Wing‐Like Structures Formed at a Negatively Charged Spacecraft Moving in a Magnetized Plasma

et al. 2020

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Spacecraft‐plasma interactions are studied with self‐consistent numerical simulations of magnetized plasmas, where electrons are strongly magnetized whereas ions are weakly magnetized. It is found that for a spacecraft in such a magnetized plasma corresponding to a low Earth orbit, electrons can be reflected from a negatively charged spacecraft and then guided by geomagnetic field lines. The reflected electrons can leave a sharp trail like wings if the spacecraft size is greater than an average electron gyroradius of the environment. Such an electron wing‐like structure is associated with propagating Langmuir waves. This results in nontrivial asymmetric electrostatic potentials close to the spacecraft and even farther than the Debye screening distance. The convective electric field also gives rise to a differential potential of the spacecraft with respect to the plasma, resulting in yet another asymmetry in the plasma dynamics and the potential distribution around the spacecraft. These asymmetries in the plasma dynamics can significantly influence in‐situ measurements of space plasma. The results show a good qualitative agreement with actual measurements by a satellite in the polar regions.

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Section: Introductionmentioning

confidence: 99%

Electron Wing‐Like Structures Formed at a Negatively Charged Spacecraft Moving in a Magnetized Plasma

et al. 2020

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“…Recently some experiments are being conducted and a few theoretical/numerical work in this regard has been reported [4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Wake effects of a stationary charged grain in streaming magnetized ions

Sundar

2018

Phys. Rev. E

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A systematic numerical study of wake potential and ion density distribution of a single grain in flowing ions under the influence of a magnetic field applied along the flow is presented. A strong magnetic field introduces ion focus depletion behind grains, facilitating the entrance of electrons far in the downstream towards the grain. It is shown that the magnetic field suppresses the amplitude of the wake potential and modifies the ion density distribution substantially. The wake peak potential and position characteristics and density distribution of plasma constituents in the presence of a magnetic field and charge-exchange collisions for the subsonic, sonic, and supersonic regime are also delineated. In the subsonic regime, simulations demonstrate the accumulation of ions near the dust grain in the transverse direction, while complete suppression of oscillations in the transverse direction takes place for the sonic and supersonic regime.

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“…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.…”

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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.

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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...

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Numerical simulations of dust charging and wakefield effects

Cited by 13 publications

References 34 publications

Electron Wing‐Like Structures Formed at a Negatively Charged Spacecraft Moving in a Magnetized Plasma

Electron Wing‐Like Structures Formed at a Negatively Charged Spacecraft Moving in a Magnetized Plasma

Wake effects of a stationary charged grain in streaming magnetized ions

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

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