Behavior of a porous particle in a radiofrequency plasma under pulsed argon ion beam bombardment

Wiese, Ruben; Sushkov, V. P.; Kersten, Holger; Ikkurthi, V. R.; Schneider, R.; Hippler, R.

doi:10.1088/1367-2630/12/3/033036

Cited by 14 publications

(10 citation statements)

References 37 publications

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“…Similarly, the potential measured above a silica dust covered surface showed ~14 V more negative than that above a smooth, solid silica surface in an identical plasma condition. The reduced SE emission yield for the dusty surface is therefore not due to different surface materials in the above experiments, rather should be mainly attributed to the re‐absorption of the emitted SEs by neighboring dust particles or structures [ Wang et al ., ; Martin and von Engel , ; Wiese et al ., ; Richterová et al ., ; Ma et al ., ]. This mechanism supports our patched charge model and should be also true for photoelectrons emitted from dusty surfaces.…”

Section: Resultssupporting

confidence: 84%

Dust charging and transport on airless planetary bodies

Wang

Schwan

Hsu

et al. 2016

Geophysical Research Letters

174

167

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We report on laboratory experiments to shed light on dust charging and transport that have been suggested to explain a variety of unusual phenomena on the surfaces of airless planetary bodies. We have recorded micron‐sized insulating dust particles jumping to several centimeters high with an initial speed of ~0.6 m/s under ultraviolet illumination or exposure to plasmas, resulting in an equivalent height of ~0.11 m on the lunar surface that is comparable to the height of the so‐called lunar horizon glow. Lofted large aggregates and surface mobilization are related to many space observations. We experimentally show that the emission and re‐absorption of photoelectron and/or secondary electron at the walls of microcavities formed between neighboring dust particles below the surface are responsible for generating unexpectedly large negative charges and intense particle‐particle repulsive forces to mobilize and lift off dust particles.

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Section: Resultssupporting

confidence: 84%

Dust charging and transport on airless planetary bodies

Wang

Schwan

Hsu

et al. 2016

Geophysical Research Letters

174

167

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“…Overall, the surface potential of aggregates shows greater fluctuation and is generally greater than that of a sphere with the same mass, due to the greater surface area of the aggregate. A similar effect has been seen in an experimental study (Wiese et al 2010). Aggregates consisting of monomers with a = 5 nm and 10 nm have a surface potential which is significantly higher than that for a sphere with the same mass.…”

Section: Model For Estimating Aggregate Chargesupporting

confidence: 84%

“…The charging of aggregate dust grains has been studied recently both in laboratory and astrophysical environments (Wiese et al 2010;Ilgner 2012;Okuzumi et al 2011); these results have shown that aggregates tend to acquire more charge when compared to spherical grains of the same mass due to the porous/fluffy structure of the aggregate, and that charged aggregates have a significant effect on subsequent dust evolution. However, there has not been a detailed study of characterizing the charge on aggregates based on structural characteristics.…”

Section: Introductionmentioning

confidence: 99%

Charging of Aggregate Grains in Astrophysical Environments

Matthews

Land³

et al. 2013

ApJ

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The charging of dust grains in astrophysical environments has been investigated with the assumption these grains are homogeneous spheres. However, there is evidence which suggests many grains in astrophysical environments are irregularly-shaped aggregates. Recent studies have shown that aggregates acquire higher charge-to-mass ratios due to their complex structures, which in turn may alter their subsequent dynamics and evolution. In this paper, the charging of aggregates is examined including secondary electron emission and photoemission in addition to primary plasma currents. The results show that the equilibrium charge on aggregates can differ markedly from spherical grains with the same mass, but that the charge can be estimated for a given environment based on structural characteristics of the grain. The "small particle effect" due to secondary electron emission is also important for determining the charge of micron-sized aggregates consisting of nano-sized particles.

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“…It has been shown that aggregates in both laboratory and astrophysical environments tend to acquire more charge compared to spherical grains of the same mass due to their porous structure [20][21][22][23]. A fluffy aggregate, consisting of many spherical monomers, has charge distributed over its irregular surface which leads to a nonzero dipole moment.…”

Section: Introductionmentioning

confidence: 99%

Measurement of net electric charge and dipole moment of dust aggregates in a complex plasma

et al. 2014

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Understanding the agglomeration of dust particles in complex plasmas requires a knowledge of the basic properties such as the net electrostatic charge and dipole moment of the dust. In this study, dust aggregates are formed from gold coated mono-disperse spherical melamine-formaldehyde monomers in a radio-frequency (rf) argon discharge plasma. The behavior of observed dust aggregates is analyzed both by studying the particle trajectories and by employing computer models examining 3D structures of aggregates and their interactions and rotations as induced by torques arising from their dipole moments. These allow the basic characteristics of the dust aggregates, such as the electrostatic charge and dipole moment, to be determined. It is shown that the experimental results support the predicted values from computer models for aggregates in these environments.

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Behavior of a porous particle in a radiofrequency plasma under pulsed argon ion beam bombardment

Cited by 14 publications

References 37 publications

Dust charging and transport on airless planetary bodies

Dust charging and transport on airless planetary bodies

Charging of Aggregate Grains in Astrophysical Environments

Measurement of net electric charge and dipole moment of dust aggregates in a complex plasma

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