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Hutchinson IH. Kinematic Mechanism of Plasma Electron Hole Transverse Instability. PHYSICAL REVIEW LETTERS 2018; 120:205101. [PMID: 29864356 DOI: 10.1103/physrevlett.120.205101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Indexed: 06/08/2023]
Abstract
It is shown through multidimensional particle-in-cell simulations that at least in Maxwellian background plasmas the long-wavelength transverse instability of plasma electron holes is caused not by the previously proposed focusing of trapped particles but instead by kinematic jetting of marginally passing electrons. The mechanism is explained and heuristic analytic estimates obtained which agree with the growth rates and transverse wave numbers observed in the simulations.
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Affiliation(s)
- I H Hutchinson
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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2
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Ivlev AV, Kompaneets R. Instabilities in bilayer complex plasmas: Wake-induced mode coupling. Phys Rev E 2017; 95:053202. [PMID: 28618606 DOI: 10.1103/physreve.95.053202] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Indexed: 11/07/2022]
Abstract
Stability principles for bilayer complex plasmas are studied. To mimic bilayer crystals and identify the main melting mechanism of such structures, a simple binary-chain model is employed. This approach provides adequate representation of the collective effects and accurate description of the interaction nonreciprocity, associated with the wake-mediated interparticle forces. It is shown that the wake-induced coupling of the wave modes sustained in different crystalline layers can trigger the dynamical instability. Furthermore, the mode coupling is demonstrated to be a universal instability mechanism, operating also in bilayer fluids. General stability criteria for the crystalline and fluid bilayers are derived.
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Affiliation(s)
- A V Ivlev
- Max-Planck-Institut für extraterrestrische Physik, 85748 Garching, Germany
| | - R Kompaneets
- Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), 82234 Weßling, Germany
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Chen M, Dropmann M, Zhang B, Matthews LS, Hyde TW. Ion-wake field inside a glass box. Phys Rev E 2016; 94:033201. [PMID: 27739748 DOI: 10.1103/physreve.94.033201] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Indexed: 11/07/2022]
Abstract
The confinement provided by a glass box is proving ideal for the formation of vertically aligned structures and a convenient method for controlling the number of dust particles comprising these dust structures as well as their sizes and shapes. In this paper, the electronic confinement of the glass box is mapped, and the particle interactions between the particle pairs inside the glass box are measured. The ion-wake field is shown to exist within the glass box, and its vertical and horizontal extents are measured.
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Affiliation(s)
- Mudi Chen
- Center for Astrophysics, Space Physics and Engineering Research, Baylor University, One Bear Place 97310, Waco, Texas 76798-7310, USA
| | - Michael Dropmann
- Center for Astrophysics, Space Physics and Engineering Research, Baylor University, One Bear Place 97310, Waco, Texas 76798-7310, USA.,Institute of Space Systems, University of Stuttgart, Raumfahrtzentrum Baden-Württemberg, Pfaffenwaldring 29,70569 Stuttgart, Germany
| | - Bo Zhang
- Center for Astrophysics, Space Physics and Engineering Research, Baylor University, One Bear Place 97310, Waco, Texas 76798-7310, USA
| | - Lorin S Matthews
- Center for Astrophysics, Space Physics and Engineering Research, Baylor University, One Bear Place 97310, Waco, Texas 76798-7310, USA
| | - Truell W Hyde
- Center for Astrophysics, Space Physics and Engineering Research, Baylor University, One Bear Place 97310, Waco, Texas 76798-7310, USA
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Melzer A. Connecting the wakefield instabilities in dusty plasmas. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 90:053103. [PMID: 25493893 DOI: 10.1103/physreve.90.053103] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Indexed: 06/04/2023]
Abstract
The wakefield, or ion focus, formed by ions streaming past dust particles trapped in the plasma sheath leads to two types of instabilities: the Schweigert instability in multilayer systems and the mode-coupling instability that already appears in single-layer dust systems. Here, a model is presented that treats both types of instability in a common description. The parameter space for the onset of the instabilities is determined. A new variant of the mode-coupling instability is found to arise from the interaction among the layers. For weak confinement, all instabilities continuously merge into each other. For stronger confinement of the dust mainly the Schweigert type of instability is observed.
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Affiliation(s)
- André Melzer
- Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald, Germany
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Mukhopadhyay AK, Goree J. Experimental measurement of velocity correlations for two microparticles in a plasma with ion flow. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 90:013102. [PMID: 25122396 DOI: 10.1103/physreve.90.013102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Indexed: 06/03/2023]
Abstract
Velocity correlations are measured in a dusty plasma with only two microparticles. These correlations allow a characterization of the oscillatory modes and an identification of the effects of ion wakes. Ion wake effects are isolated by comparing two experiments with the microparticles aligned parallel vs perpendicular to the ion flow. From records of microparticle velocities, the one- and two-particle distribution functions f(1) and f(2) are obtained, and the two-particle correlation function g(2) ≡ f(2)-f(1)f(1) is calculated. Comparing the two experiments, we find that motion is much more correlated when the microparticles are aligned with the ion flow and the character of the oscillatory modes depends on the ion flow direction due to the ion wake.
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Affiliation(s)
- Amit K Mukhopadhyay
- Department of Physics and Astronomy, The University of Iowa, Iowa City, Iowa 52242, USA
| | - J Goree
- Department of Physics and Astronomy, The University of Iowa, Iowa City, Iowa 52242, USA
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Melzer A, Schella A. Symbolic transfer entropy analysis of the dust interaction in the presence of wakefields in dusty plasmas. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 89:041103. [PMID: 24827184 DOI: 10.1103/physreve.89.041103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Indexed: 05/27/2023]
Abstract
The method of symbolic transfer entropy has been applied to analyze the behavior of charged-particle systems under the influence of an ion focus (wakefield) in a dusty plasma. Using long-run experiments under various plasma and trapping conditions, it is revealed from the transfer entropy that information is transported from the upper particle in an ion flow to the lower. The information transfer increases with smaller interparticle distance and with reduced height in the sheath. This can be consistently explained by the formation of the ion focus by an ion flow in the sheath. From the analysis of two-particle and many-particle systems, the symbolic entropy transfer can be judged as a reliable measure for information asymmetry, and hence interaction asymmetry, in dusty plasma systems.
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Affiliation(s)
- André Melzer
- Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald, Germany
| | - André Schella
- Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald, Germany
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Melzer A, Schella A, Mulsow M. Nonequilibrium finite dust clusters: connecting normal modes and wakefields. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 89:013109. [PMID: 24580348 DOI: 10.1103/physreve.89.013109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Indexed: 06/03/2023]
Abstract
The dynamic properties of finite three-dimensional dust clusters in a dusty plasma under the influence of an ion focus are studied by normal modes. The mode analysis has been extended to account for the ion focus using the point-charge model for the horizontal interaction of the dust particles. From that, an analytical model for a few-particle system is derived accounting for three distinct dynamical regimes at different focus strengths, namely, absolutely unstable and fully stable configurations as well as an unstable oscillatory regime. The techniques of normal mode analysis (NMA) and instantaneous normal modes (INM) extended by the ion focus have been applied to dust systems in the experiment and compared to the model. From this, the ion focus strength has been derived. The specific sensitivity of NMA and INM allows one to identify equilibrium configurations in this nonequilibrium environment for these finite clusters.
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Affiliation(s)
- André Melzer
- Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald, Germany
| | - André Schella
- Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald, Germany
| | - Matthias Mulsow
- Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald, Germany
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Hutchinson IH. Intergrain forces in low-Mach-number plasma wakes. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 85:066409. [PMID: 23005230 DOI: 10.1103/physreve.85.066409] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Indexed: 06/01/2023]
Abstract
Large-scale particle-in-cell calculations of the plasma wake interactions of two negatively charged grains smaller than the Debye length are carried out using the coptic code over a wide range of subsonic plasma flow velocities. In plasmas with the temperature ratio T(e)/T(i)=100, it is found that a single grain's oscillatory wake disappears for flow Mach numbers M less than approximately 0.3, which is the parameter regime where Landau damping is expected to be strong. Neutral collisions suppress potential oscillations above M=0.3, but not the trailing attractive potential peak caused by ion focusing. The transverse (grain-aligning) force on a downstream particle in the wake of another is obtained rigorously from the code in three-dimensional simulations. It shows general agreement with the force that would be deduced from the single-grain wake potential gradient. Except for relatively large grains in the nonlinear collisional regime, the grain-aligning force is very small for slow flow.
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Affiliation(s)
- I H Hutchinson
- Plasma Science and Fusion Center and Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Arp O, Goree J, Piel A. Particle chains in a dilute dusty plasma with subsonic ion flow. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 85:046409. [PMID: 22680588 DOI: 10.1103/physreve.85.046409] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 03/02/2012] [Indexed: 06/01/2023]
Abstract
Chains of charged dust particles are observed aligned with a subsonic ion flow. These chains are found in dilute regions, near the midplane of a parallel-plate radio-frequency plasma under microgravity conditions. The argon ion flow speed near these chains was estimated to be of order 10(2) m/s, corresponding to an ion acoustic Mach number M<0.1. The chains were observed to be stable in both the longitudinal and transverse directions. This stability suggests that there is a transverse restoring force. The transverse components of the ion-drag force or electrostatic wake-field forces could provide such a stabilizing effect. The chain appears to terminate with a final dust particle that is located in a dilute region; this observation suggests a possible attractive force in the longitudinal direction in the presence of a subsonic ion flow.
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Affiliation(s)
- O Arp
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, D-24098 Kiel, Germany
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