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Dimmock AP, Nykyri K, Osmane A, Karimabadi H, Pulkkinen TI. Dawn-Dusk Asymmetries of the Earth's Dayside Magnetosheath in the Magnetosheath Interplanetary Medium Reference Frame. ACTA ACUST UNITED AC 2017. [DOI: 10.1002/9781119216346.ch5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
Affiliation(s)
- A. P. Dimmock
- School of Electrical Engineering; Aalto University; Espoo Finland
| | - K. Nykyri
- Department of Physical Sciences; Embry-Riddle Aeronautical University; Daytona Beach Florida USA
| | - A. Osmane
- School of Electrical Engineering; Aalto University; Espoo Finland
| | - H. Karimabadi
- University of California; San Diego, La Jolla California
- SciberQuest, Inc.; Del Mar California USA
| | - T. I. Pulkkinen
- School of Electrical Engineering; Aalto University; Espoo Finland
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2
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Stanier A, Daughton W, Chacón L, Karimabadi H, Ng J, Huang YM, Hakim A, Bhattacharjee A. Role of Ion Kinetic Physics in the Interaction of Magnetic Flux Ropes. Phys Rev Lett 2015; 115:175004. [PMID: 26551121 DOI: 10.1103/physrevlett.115.175004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Indexed: 06/05/2023]
Abstract
To explain many natural magnetized plasma phenomena, it is crucial to understand how rates of collisionless magnetic reconnection scale in large magnetohydrodynamic (MHD) scale systems. Simulations of isolated current sheets conclude such rates are independent of system size and can be reproduced by the Hall-MHD model, but neglect sheet formation and coupling to MHD scales. Here, it is shown for the problem of flux-rope merging, which includes this formation and coupling, that the Hall-MHD model fails to reproduce the kinetic results. The minimum sufficient model must retain ion kinetic effects, which set the ion diffusion region geometry and give time-averaged rates that reduce significantly with system size, leading to different global evolution in large systems.
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Affiliation(s)
- A Stanier
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - W Daughton
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - L Chacón
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - H Karimabadi
- SciberQuest, Inc., Del Mar, California 92014, USA
| | - J Ng
- Center for Heliophysics, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - Y-M Huang
- Center for Heliophysics, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - A Hakim
- Center for Heliophysics, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - A Bhattacharjee
- Center for Heliophysics, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
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3
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Wan M, Matthaeus WH, Roytershteyn V, Karimabadi H, Parashar T, Wu P, Shay M. Intermittent Dissipation and Heating in 3D Kinetic Plasma Turbulence. Phys Rev Lett 2015; 114:175002. [PMID: 25978241 DOI: 10.1103/physrevlett.114.175002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Indexed: 06/04/2023]
Abstract
High resolution, fully kinetic, three dimensional (3D) simulation of collisionless plasma turbulence shows the development of turbulence characterized by sheetlike current density structures spanning a range of scales. The nonlinear evolution is initialized with a long wavelength isotropic spectrum of fluctuations having polarizations transverse to an imposed mean magnetic field. We present evidence that these current sheet structures are sites for heating and dissipation, and that stronger currents signify higher dissipation rates. The analyses focus on quantities such as J·E, electron, and proton temperatures, and conditional averages of these quantities based on local electric current density. Evidently, kinetic scale plasma, like magnetohydrodynamics, becomes intermittent due to current sheet formation, leading to the expectation that heating and dissipation in astrophysical and space plasmas may be highly nonuniform. Comparison with previous results from 2D kinetic simulations, as well as high frequency solar wind observational data, are discussed.
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Affiliation(s)
- M Wan
- Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | - W H Matthaeus
- Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | | | | | - T Parashar
- Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | - P Wu
- Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | - M Shay
- Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
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Liu YH, Daughton W, Karimabadi H, Li H, Roytershteyn V. Bifurcated structure of the electron diffusion region in three-dimensional magnetic reconnection. Phys Rev Lett 2013; 110:265004. [PMID: 23848886 DOI: 10.1103/physrevlett.110.265004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Indexed: 06/02/2023]
Abstract
Three-dimensional kinetic simulations of magnetic reconnection reveal that the electron diffusion region is composed of two or more current sheets in regimes with weak magnetic shear angles ϕ≲80°. This new morphology is explained by oblique tearing modes which produce flux ropes while simultaneously driving enhanced current at multiple resonance surfaces. This physics persists into the nonlinear regime leading to multiple electron layers embedded within a larger Alfvénic inflow and outflow. Surprisingly, the thickness of these layers and the reconnection rate both remain comparable to two-dimensional models. The parallel electric fields are supported predominantly by the electron pressure tensor and electron inertia, while turbulent dissipation remains small.
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Affiliation(s)
- Yi-Hsin Liu
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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5
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Leonardis E, Chapman SC, Daughton W, Roytershteyn V, Karimabadi H. Identification of intermittent multifractal turbulence in fully kinetic simulations of magnetic reconnection. Phys Rev Lett 2013; 110:205002. [PMID: 25167422 DOI: 10.1103/physrevlett.110.205002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Indexed: 06/03/2023]
Abstract
Recent fully nonlinear, kinetic three-dimensional simulations of magnetic reconnection [W. Daughton et al., Nat. Phys. 7, 539 (2011)] evolve structures and exhibit dynamics on multiple scales, in a manner reminiscent of turbulence. These simulations of reconnection are among the first to be performed at sufficient spatiotemporal resolution to allow formal quantitative analysis of statistical scaling, which we present here. We find that the magnetic field fluctuations generated by reconnection are anisotropic, have nontrivial spatial correlation, and exhibit the hallmarks of finite range fluid turbulence: they have non-Gaussian distributions, exhibit extended self-similarity in their scaling, and are spatially multifractal. Furthermore, we find that the rate at which the fields do work on the particles, J · E, is also multifractal, so that magnetic energy is converted to plasma kinetic energy in a manner that is spatially intermittent. This suggests that dissipation in this sense in collisionless reconnection on kinetic scales has an analogue in fluidlike turbulent phenomenology, in that it proceeds via multifractal structures generated by an intermittent cascade.
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Affiliation(s)
- E Leonardis
- Department of Physics, Centre for Fusion, Space and Astrophysics, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - S C Chapman
- Department of Physics, Centre for Fusion, Space and Astrophysics, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - W Daughton
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - V Roytershteyn
- University of California, San Diego, La Jolla, California 92093, USA
| | - H Karimabadi
- University of California, San Diego, La Jolla, California 92093, USA
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Le A, Egedal J, Ohia O, Daughton W, Karimabadi H, Lukin VS. Regimes of the electron diffusion region in magnetic reconnection. Phys Rev Lett 2013; 110:135004. [PMID: 23581331 DOI: 10.1103/physrevlett.110.135004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Indexed: 06/02/2023]
Abstract
The electron diffusion region during magnetic reconnection lies in different regimes depending on the pressure anisotropy, which is regulated by the properties of thermal electron orbits. In kinetic simulations at the weakest guide fields, pitch angle mixing in velocity space causes the outflow electron pressure to become nearly isotropic. Above a threshold guide field that depends on a range of parameters, including the normalized electron pressure and the ion-to-electron mass ratio, electron pressure anisotropy develops in the exhaust and supports extended current layers. This new regime with electron current sheets extending to the system size is also reproduced by fluid simulations with an anisotropic closure for the electron pressure. It offers an explanation for recent spacecraft observations.
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Affiliation(s)
- A Le
- Department of Physics, Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Wan M, Matthaeus WH, Karimabadi H, Roytershteyn V, Shay M, Wu P, Daughton W, Loring B, Chapman SC. Intermittent dissipation at kinetic scales in collisionless plasma turbulence. Phys Rev Lett 2012; 109:195001. [PMID: 23215389 DOI: 10.1103/physrevlett.109.195001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Indexed: 06/01/2023]
Abstract
High resolution kinetic simulations of collisionless plasma driven by shear show the development of turbulence characterized by dynamic coherent sheetlike current density structures spanning a range of scales down to electron scales. We present evidence that these structures are sites for heating and dissipation, and that stronger current structures signify higher dissipation rates. Evidently, kinetic scale plasma, like magnetohydrodynamics, becomes intermittent due to current sheet formation, leading to the expectation that heating and dissipation in astrophysical and space plasmas may be highly nonuniform and patchy.
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Affiliation(s)
- M Wan
- Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
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8
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Omelchenko YA, Karimabadi H. Spontaneous generation of a sheared plasma rotation in a field-reversed θ-pinch discharge. Phys Rev Lett 2012; 109:065004. [PMID: 23006277 DOI: 10.1103/physrevlett.109.065004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Indexed: 06/01/2023]
Abstract
By conducting two-dimensional hybrid simulations of an infinitely long field-reversed θ-pinch discharge we discover a new type of plasma rotation, which rapidly develops at the plasma edge in the ion diamagnetic direction due to the self-consistent generation of a Hall-driven radial electric field. This effect is different from the previously identified end-shorting and particle-loss mechanisms. We also demonstrate flutelike perturbations frequently inferred in experiments and show that in the absence of axial contraction effects they may quickly alter the toroidal symmetry of the plasma.
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Scudder JD, Holdaway RD, Daughton WS, Karimabadi H, Roytershteyn V, Russell CT, Lopez JY. First resolved observations of the demagnetized electron-diffusion region of an astrophysical magnetic-reconnection site. Phys Rev Lett 2012; 108:225005. [PMID: 23003609 DOI: 10.1103/physrevlett.108.225005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Indexed: 06/01/2023]
Abstract
Spatially resolved, diagnostic signatures across the X-line and electron-diffusion region (EDR) by the Polar spacecraft are reported at Earth's magnetopause. The X-line traversal has a local electron's skin depth scale. First, resolved EDR profiles are presented with peak electron thermal Mach numbers >1.5, anisotropy >7, calibrated electron agyrotropy >1, and misordered expansion parameters indicative of demagnetization and strong (150 eV) increases in electron temperature. The amplitude and phase of these profiles correlate well with a guide geometry kinetic simulation of collisionless magnetic reconnection. Such high resolution diagnosis has been made possible by data processing techniques that afford an 11-fold reduction in the aliasing time for the electron moments.
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Affiliation(s)
- J D Scudder
- University of Iowa, Iowa City, Iowa 52442, USA
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Roytershteyn V, Daughton W, Karimabadi H, Mozer FS. Influence of the lower-hybrid drift instability on magnetic reconnection in asymmetric configurations. Phys Rev Lett 2012; 108:185001. [PMID: 22681084 DOI: 10.1103/physrevlett.108.185001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Indexed: 06/01/2023]
Abstract
Using fully kinetic 3D simulations of magnetic reconnection in asymmetric antiparallel configurations, we demonstrate that an electromagnetic lower-hybrid drift instability (LHDI) localized near the X line can substantially modify the reconnection mechanism in the regimes with large asymmetry, a moderate ratio of electron to ion temperature, and low plasma β. However, the mode saturates at a small amplitude in the regimes typical of Earth's magnetopause. In these cases, LHDI-driven turbulence is predominantly localized along the separatrices on the low-β side of the current sheet, in agreement with spacecraft observations.
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Affiliation(s)
- V Roytershteyn
- University of California, San Diego, La Jolla, California 92093, USA
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Karimabadi H, Dorelli J, Roytershteyn V, Daughton W, Chacón L. Flux pileup in collisionless magnetic reconnection: bursty interaction of large flux ropes. Phys Rev Lett 2011; 107:025002. [PMID: 21797613 DOI: 10.1103/physrevlett.107.025002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Indexed: 05/31/2023]
Abstract
Using fully kinetic simulations of the island coalescence problem for a range of system sizes greatly exceeding kinetic scales, the phenomenon of flux pileup in the collisionless regime is demonstrated. While small islands on the scale of λ ≤ 5 ion inertial length (d(i)) coalesce rapidly and do not support significant flux pileup, coalescence of larger islands is characterized by large flux pileup and a weaker time averaged reconnection rate that scales as √(d(i)/λ) while the peak rate remains nearly independent of island size. For the largest islands (λ = 100d(i)), reconnection is bursty and nearly shuts off after the first bounce, reconnecting ~20% of the available flux.
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Affiliation(s)
- H Karimabadi
- University of California at San Diego, La Jolla, California 92093, USA
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Daughton W, Roytershteyn V, Albright BJ, Karimabadi H, Yin L, Bowers KJ. Transition from collisional to kinetic regimes in large-scale reconnection layers. Phys Rev Lett 2009; 103:065004. [PMID: 19792577 DOI: 10.1103/physrevlett.103.065004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2009] [Indexed: 05/28/2023]
Abstract
Using fully kinetic simulations with a Fokker-Planck collision operator, it is demonstrated that Sweet-Parker reconnection layers are unstable to plasmoids (secondary islands) for Lundquist numbers beyond S greater, similar 1000. The instability is increasingly violent at higher Lundquist numbers, both in terms of the number of plasmoids produced and the super-Alfvénic growth rate. A dramatic enhancement in the reconnection rate is observed when the half-thickness of the current sheet between two plasmoids approaches the ion inertial length. During this transition to kinetic scales, the reconnection electric field rapidly exceeds the runaway limit, resulting in the formation of electron-scale current layers that are unstable to the continual formation of new plasmoids.
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Affiliation(s)
- W Daughton
- Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA
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13
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Yin L, Daughton W, Karimabadi H, Albright BJ, Bowers KJ, Margulies J. Three-dimensional dynamics of collisionless magnetic reconnection in large-scale pair plasmas. Phys Rev Lett 2008; 101:125001. [PMID: 18851379 DOI: 10.1103/physrevlett.101.125001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2008] [Indexed: 05/26/2023]
Abstract
Using the largest three-dimensional particle-in-cell simulations to date, collisionless magnetic reconnection in large-scale electron-positron plasmas without a guide field is shown to involve complex interaction of tearing and kink modes. The reconnection onset is patchy and occurs at multiple sites which self-organize to form a single, large diffusion region. The diffusion region tends to elongate in the outflow direction and become unstable to secondary kinking and formation of "plasmoid-rope" structures with finite extent in the current direction. The secondary kink folds the reconnection current layer, while plasmoid ropes at times follow the folding of the current layer. The interplay between these secondary instabilities plays a key role in controlling the time-dependent reconnection rate in large-scale systems.
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Affiliation(s)
- L Yin
- Los Alamos National Laboratory, Los Alamos, NM 87544, USA
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14
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Karimabadi H. On magnetic reconnection regimes and associated three-dimensional asymmetries: Hybrid, Hall-less hybrid, and Hall-MHD simulations. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2004ja010478] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Karimabadi H, Krauss-Varban D, Omidi N, Vu HX. Magnetic structure of the reconnection layer and core field generation in plasmoids. ACTA ACUST UNITED AC 1999. [DOI: 10.1029/1999ja900089] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Quest KB, Karimabadi H, Brittnacher M. Consequences of particle conservation along a flux surface for magnetotail tearing. ACTA ACUST UNITED AC 1996. [DOI: 10.1029/95ja02986] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Terasawa T, Fujimoto M, Karimabadi H, Omidi N. Anomalous ion mixing within a Kelvin-Helmholtz vortex in a collisionless plasma. Phys Rev Lett 1992; 68:2778-2781. [PMID: 10045490 DOI: 10.1103/physrevlett.68.2778] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Pritchett PL, Coroniti FV, Pellat R, Karimabadi H. Collisionless reconnection in two-dimensional magnetotail equilibria. ACTA ACUST UNITED AC 1991. [DOI: 10.1029/91ja01094] [Citation(s) in RCA: 97] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Menyuk CR, Drobot AT, Papadopoulos K, Karimabadi H. Stochastic electron acceleration in obliquely propagating, electromagnetic waves. Phys Rev Lett 1987; 58:2071-2074. [PMID: 10034642 DOI: 10.1103/physrevlett.58.2071] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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