1
|
Shi P, Scime EE, Barbhuiya MH, Cassak PA, Adhikari S, Swisdak M, Stawarz JE. Using Direct Laboratory Measurements of Electron Temperature Anisotropy to Identify the Heating Mechanism in Electron-Only Guide Field Magnetic Reconnection. Phys Rev Lett 2023; 131:155101. [PMID: 37897764 DOI: 10.1103/physrevlett.131.155101] [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: 03/31/2023] [Revised: 07/21/2023] [Accepted: 09/12/2023] [Indexed: 10/30/2023]
Abstract
Anisotropic electron heating during electron-only magnetic reconnection with a large guide magnetic field is directly measured in a laboratory plasma through in situ measurements of electron velocity distribution functions. Electron heating preferentially parallel to the magnetic field is localized to one separatrix, and anisotropies of 1.5 are measured. The mechanism for electron energization is identified as the parallel reconnection electric field because of the anisotropic nature of the heating and spatial localization. These characteristics are reproduced in a 2D particle-in-cell simulation and are also consistent with numerous magnetosheath observations. A measured increase in the perpendicular temperature along both separatrices is not reproduced by our 2D simulations. This work has implications for energy partition studies in magnetosheath and laboratory reconnection.
Collapse
Affiliation(s)
- Peiyun Shi
- Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08542, USA
| | - Earl E Scime
- Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA
| | - M Hasan Barbhuiya
- Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA
| | - Paul A Cassak
- Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA
| | - Subash Adhikari
- Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA
| | - M Swisdak
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, USA
| | - Julia E Stawarz
- Department of Mathematics, Physics, and Electrical Engineering, Northumbria University, Newcastle upon Tyne NE1 8ST, United Kingdom
| |
Collapse
|
2
|
Bale SD, Drake JF, McManus MD, Desai MI, Badman ST, Larson DE, Swisdak M, Horbury TS, Raouafi NE, Phan T, Velli M, McComas DJ, Cohen CMS, Mitchell D, Panasenco O, Kasper JC. Interchange reconnection as the source of the fast solar wind within coronal holes. Nature 2023; 618:252-256. [PMID: 37286648 DOI: 10.1038/s41586-023-05955-3] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 03/14/2023] [Indexed: 06/09/2023]
Abstract
The fast solar wind that fills the heliosphere originates from deep within regions of open magnetic field on the Sun called 'coronal holes'. The energy source responsible for accelerating the plasma is widely debated; however, there is evidence that it is ultimately magnetic in nature, with candidate mechanisms including wave heating1,2 and interchange reconnection3-5. The coronal magnetic field near the solar surface is structured on scales associated with 'supergranulation' convection cells, whereby descending flows create intense fields. The energy density in these 'network' magnetic field bundles is a candidate energy source for the wind. Here we report measurements of fast solar wind streams from the Parker Solar Probe (PSP) spacecraft6 that provide strong evidence for the interchange reconnection mechanism. We show that the supergranulation structure at the coronal base remains imprinted in the near-Sun solar wind, resulting in asymmetric patches of magnetic 'switchbacks'7,8 and bursty wind streams with power-law-like energetic ion spectra to beyond 100 keV. Computer simulations of interchange reconnection support key features of the observations, including the ion spectra. Important characteristics of interchange reconnection in the low corona are inferred from the data, including that the reconnection is collisionless and that the energy release rate is sufficient to power the fast wind. In this scenario, magnetic reconnection is continuous and the wind is driven by both the resulting plasma pressure and the radial Alfvénic flow bursts.
Collapse
Affiliation(s)
- S D Bale
- Physics Department, University of California, Berkeley, CA, USA.
- Space Sciences Laboratory, University of California, Berkeley, CA, USA.
| | - J F Drake
- Department of Physics, the Institute for Physical Science and Technology and the Joint Space Institute, University of Maryland, College Park, MD, USA
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD, USA
| | - M D McManus
- Physics Department, University of California, Berkeley, CA, USA
- Space Sciences Laboratory, University of California, Berkeley, CA, USA
| | - M I Desai
- Southwest Research Institute, San Antonio, TX, USA
| | - S T Badman
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA
| | - D E Larson
- Space Sciences Laboratory, University of California, Berkeley, CA, USA
| | - M Swisdak
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD, USA
| | - T S Horbury
- The Blackett Laboratory, Imperial College London, London, UK
| | - N E Raouafi
- Johns Hopkins Applied Physics Laboratory, Laurel, MD, USA
| | - T Phan
- Space Sciences Laboratory, University of California, Berkeley, CA, USA
| | - M Velli
- Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, CA, USA
- International Space Science Institute, Bern, Switzerland
| | - D J McComas
- Department of Astrophysical Sciences, Princeton University, Princeton, NJ, USA
| | - C M S Cohen
- California Institute of Technology, Pasadena, CA, USA
| | - D Mitchell
- Johns Hopkins Applied Physics Laboratory, Laurel, MD, USA
| | - O Panasenco
- Advanced Heliophysics Inc., Los Angeles, CA, USA
| | - J C Kasper
- BWX Technologies, Inc., Washington, DC, USA
- Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
3
|
Shi P, Srivastav P, Barbhuiya MH, Cassak PA, Scime EE, Swisdak M. Laboratory Observations of Electron Heating and Non-Maxwellian Distributions at the Kinetic Scale during Electron-Only Magnetic Reconnection. Phys Rev Lett 2022; 128:025002. [PMID: 35089758 DOI: 10.1103/physrevlett.128.025002] [Citation(s) in RCA: 1] [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: 10/06/2021] [Accepted: 12/08/2021] [Indexed: 06/14/2023]
Abstract
Non-Maxwellian electron velocity distribution functions composed of a warm bulk population and a cold beam are directly measured during electron-only reconnection with a strong out-of-plane (guide) magnetic field in a laboratory plasma. Electron heating is localized to the separatrix, and the electron temperature increases continuously along the separatrix. The measured gain in enthalpy flux is 70% of the incoming Poynting flux. The electron beams are oppositely directed on either side of the X point, and their velocities are comparable to, and scale with, the electron Alfvén speed. Particle-in-cell simulations are consistent with the measurements. The experimental results are consistent with, and go beyond, recent observations in the magnetosheath.
Collapse
Affiliation(s)
- Peiyun Shi
- Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA
| | - Prabhakar Srivastav
- Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA
| | - M Hasan Barbhuiya
- Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA
| | - Paul A Cassak
- Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA
| | - Earl E Scime
- Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA
| | - M Swisdak
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, USA
| |
Collapse
|
4
|
Arnold H, Drake JF, Swisdak M, Guo F, Dahlin JT, Chen B, Fleishman G, Glesener L, Kontar E, Phan T, Shen C. Electron Acceleration during Macroscale Magnetic Reconnection. Phys Rev Lett 2021; 126:135101. [PMID: 33861105 DOI: 10.1103/physrevlett.126.135101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 01/19/2021] [Accepted: 03/01/2021] [Indexed: 06/12/2023]
Abstract
The first self-consistent simulations of electron acceleration during magnetic reconnection in a macroscale system are presented. Consistent with solar flare observations, the spectra of energetic electrons take the form of power laws that extend more than two decades in energy. The drive mechanism for these nonthermal electrons is Fermi reflection in growing and merging magnetic flux ropes. A strong guide field suppresses the production of nonthermal electrons by weakening the Fermi drive mechanism. For a weak guide field the total energy content of nonthermal electrons dominates that of the hot thermal electrons even though their number density remains small. Our results are benchmarked with the hard x-ray, radio, and extreme ultraviolet observations of the X8.2-class solar flare on September 10, 2017.
Collapse
Affiliation(s)
- H Arnold
- IREAP, University of Maryland, College Park, Maryland 20742-3511, USA
| | - J F Drake
- IREAP, University of Maryland, College Park, Maryland 20742-3511, USA
| | - M Swisdak
- IREAP, University of Maryland, College Park, Maryland 20742-3511, USA
| | - F Guo
- Los Alamos National Lab, Los Alamos, New Mexico 87545, USA
| | - J T Dahlin
- NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - B Chen
- New Jersey Institute of technology, Newark, New Jersey 07102, USA
| | - G Fleishman
- New Jersey Institute of technology, Newark, New Jersey 07102, USA
| | - L Glesener
- University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - E Kontar
- University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - T Phan
- University of California, Berkeley, California 94720, USA
| | - C Shen
- Harvard University, Cambridge, Massachusetts 02138, USA
| |
Collapse
|
5
|
Liang H, Cassak PA, Swisdak M, Servidio S. Estimating Effective Collision Frequency and Kinetic Entropy Uncertainty in Particle-in-Cell Simulations. ACTA ACUST UNITED AC 2020. [DOI: 10.1088/1742-6596/1620/1/012009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
6
|
Roberg-Clark GT, Drake JF, Reynolds CS, Swisdak M. Suppression of Electron Thermal Conduction by Whistler Turbulence in a Sustained Thermal Gradient. Phys Rev Lett 2018; 120:035101. [PMID: 29400540 DOI: 10.1103/physrevlett.120.035101] [Citation(s) in RCA: 3] [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: 08/31/2017] [Revised: 11/13/2017] [Indexed: 06/07/2023]
Abstract
The dynamics of weakly magnetized collisionless plasmas in the presence of an imposed temperature gradient along an ambient magnetic field is explored with particle-in-cell simulations and modeling. Two thermal reservoirs at different temperatures drive an electron heat flux that destabilizes off-angle whistler-type modes. The whistlers grow to large amplitude, δB/B_{0}≃1, and resonantly scatter the electrons, significantly reducing the heat flux. Surprisingly, the resulting steady-state heat flux is largely independent of the thermal gradient. The rate of thermal conduction is instead controlled by the finite propagation speed of the whistlers, which act as mobile scattering centers that convect the thermal energy of the hot reservoir. The results are relevant to thermal transport in high-β astrophysical plasmas such as hot accretion flows and the intracluster medium of galaxy clusters.
Collapse
Affiliation(s)
- G T Roberg-Clark
- Department of Physics, University of Maryland College Park, College Park, Maryland 20740, USA
| | - J F Drake
- Department of Physics, University of Maryland College Park, College Park, Maryland 20740, USA
- Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, USA
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, USA
- Joint Space-Science Institute (JSI), College Park, Maryland 20742, USA
| | - C S Reynolds
- Joint Space-Science Institute (JSI), College Park, Maryland 20742, USA
- Department of Astronomy, University of Maryland College Park, College Park, Maryland 20740, USA
- Institute of Astronomy, Madingley Road, Cambridge CB3 OHA, United Kingdom
| | - M Swisdak
- Department of Physics, University of Maryland College Park, College Park, Maryland 20740, USA
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, USA
- Joint Space-Science Institute (JSI), College Park, Maryland 20742, USA
| |
Collapse
|
7
|
Wu P, Wan M, Matthaeus WH, Shay MA, Swisdak M. Von Kármán energy decay and heating of protons and electrons in a kinetic turbulent plasma. Phys Rev Lett 2013; 111:121105. [PMID: 24093244 DOI: 10.1103/physrevlett.111.121105] [Citation(s) in RCA: 9] [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: 06/14/2013] [Indexed: 06/02/2023]
Abstract
Decay in time of undriven weakly collisional kinetic plasma turbulence in systems large compared to the ion kinetic scales is investigated using fully electromagnetic particle-in-cell simulations initiated with transverse flow and magnetic disturbances, constant density, and a strong guide field. The observed energy decay is consistent with the von Kármán hypothesis of similarity decay, in a formulation adapted to magnetohydrodyamics. Kinetic dissipation occurs at small scales, but the overall rate is apparently controlled by large scale dynamics. At small turbulence amplitudes the electrons are preferentially heated. At larger amplitudes proton heating is the dominant effect. In the solar wind and corona the protons are typically hotter, suggesting that these natural systems are in the large amplitude turbulence regime.
Collapse
Affiliation(s)
- P Wu
- Department of Physics and Astronomy, Bartol Research Institute, University of Delaware, Newark, Delaware 19716, USA
| | | | | | | | | |
Collapse
|
8
|
Fermo RL, Drake JF, Swisdak M. Secondary magnetic islands generated by the Kelvin-Helmholtz instability in a reconnecting current sheet. Phys Rev Lett 2012; 108:255005. [PMID: 23004610 DOI: 10.1103/physrevlett.108.255005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Indexed: 06/01/2023]
Abstract
Magnetic islands or flux ropes produced by magnetic reconnection have been observed on the magnetopause, in the magnetotail, and in coronal current sheets. Particle-in-cell simulations of magnetic reconnection with a guide field produce elongated electron current layers that spontaneously produce secondary islands. Here, we explore the seed mechanism that gives birth to these islands. The most commonly suggested theory for island formation is the tearing instability. We demonstrate that in our simulations these structures typically start out, not as magnetic islands, but as electron flow vortices within the electron current sheet. When some of these vortices first form, they do not coincide with closed magnetic field lines, as would be the case if they were islands. Only after they have grown larger than the electron skin depth do they couple to the magnetic field and seed the growth of finite-sized islands. The streaming of electrons along the magnetic separatrix produces the flow shear necessary to drive an electron Kelvin-Helmholtz instability and produce the initial vortices. The conditions under which this instability is the dominant mechanism for seeding magnetic islands are explored.
Collapse
Affiliation(s)
- R L Fermo
- Center for Space Physics, Astronomy Department, Boston University, Boston, Massachusetts 02215, USA
| | | | | |
Collapse
|
9
|
Che H, Drake JF, Swisdak M, Yoon PH. Nonlinear development of streaming instabilities in strongly magnetized plasma. Phys Rev Lett 2009; 102:145004. [PMID: 19392448 DOI: 10.1103/physrevlett.102.145004] [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: 11/25/2008] [Indexed: 05/27/2023]
Abstract
The nonlinear development of streaming instabilities in the current layers formed during magnetic reconnection with a guide field is explored. Theory and 3D particle-in-cell simulations reveal two distinct phases. First, the parallel Buneman instability grows and traps low velocity electrons. The remaining electrons then drive two forms of turbulence: the parallel electron-electron two-stream instability and the nearly perpendicular lower-hybrid instability. The high velocity electrons resonate with the turbulence and transfer momentum to the ions and low velocity electrons.
Collapse
Affiliation(s)
- H Che
- IREAP, Department of Physics, University of Maryland, College Park, Maryland 20742, USA
| | | | | | | |
Collapse
|
10
|
Zhang XL, Fletcher RS, Rolston SL, Guzdar PN, Swisdak M. Ultracold plasma expansion in a magnetic field. Phys Rev Lett 2008; 100:235002. [PMID: 18643512 DOI: 10.1103/physrevlett.100.235002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2007] [Indexed: 05/26/2023]
Abstract
We measure the expansion of an ultracold plasma across the field lines of a uniform magnetic field. We image the ion distribution by extracting the ions with a high-voltage pulse onto a position-sensitive detector. Early in the lifetime of the plasma (<20 micros), the size of the image is dominated by the time-of-flight Coulomb explosion of the dense ion cloud. For later times, we measure the 2D Gaussian width of the ion image, obtaining the transverse expansion velocity as a function of the magnetic field (up to 70 G). We observe that the expansion velocity scales as B(-1/2), explained by a nonlinear ambipolar diffusion model with anisotropic diffusion in two different directions.
Collapse
Affiliation(s)
- X L Zhang
- Joint Quantum Institute, Department of Physics, University of Maryland, College Park, MD 20742, USA
| | | | | | | | | |
Collapse
|
11
|
Shay MA, Drake JF, Swisdak M. Two-scale structure of the electron dissipation region during collisionless magnetic reconnection. Phys Rev Lett 2007; 99:155002. [PMID: 17995175 DOI: 10.1103/physrevlett.99.155002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2007] [Indexed: 05/25/2023]
Abstract
Particle-in-cell simulations of collisionless magnetic reconnection are presented that demonstrate that reconnection remains fast in very large systems. The electron dissipation region develops a distinct two-scale structure along the outflow direction. Consistent with fast reconnection, the length of the electron current layer stabilizes and decreases with decreasing electron mass, approaching the ion inertial length for a proton-electron plasma. Surprisingly, the electrons form a super-Alfvénic outflow jet that remains decoupled from the magnetic field and extends large distances downstream from the x line.
Collapse
Affiliation(s)
- M A Shay
- Department of Physics & Astronomy, 217 Sharp Lab, University of Delaware, Newark, Delaware 19716, USA.
| | | | | |
Collapse
|
12
|
Drake JF, Swisdak M, Che H, Shay MA. Electron acceleration from contracting magnetic islands during reconnection. Nature 2006; 443:553-6. [PMID: 17024088 DOI: 10.1038/nature05116] [Citation(s) in RCA: 690] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2005] [Accepted: 07/19/2006] [Indexed: 11/08/2022]
Abstract
A long-standing problem in the study of space and astrophysical plasmas is to explain the production of energetic electrons as magnetic fields 'reconnect' and release energy. In the Earth's magnetosphere, electron energies reach hundreds of thousands of electron volts (refs 1-3), whereas the typical electron energies associated with large-scale reconnection-driven flows are just a few electron volts. Recent observations further suggest that these energetic particles are produced in the region where the magnetic field reconnects. In solar flares, upwards of 50 per cent of the energy released can appear as energetic electrons. Here we show that electrons gain kinetic energy by reflecting from the ends of the contracting 'magnetic islands' that form as reconnection proceeds. The mechanism is analogous to the increase of energy of a ball reflecting between two converging walls--the ball gains energy with each bounce. The repetitive interaction of electrons with many islands allows large numbers to be efficiently accelerated to high energy. The back pressure of the energetic electrons throttles reconnection so that the electron energy gain is a large fraction of the released magnetic energy. The resultant energy spectra of electrons take the form of power laws with spectral indices that match the magnetospheric observations.
Collapse
Affiliation(s)
- J F Drake
- University of Maryland, College Park, Maryland 20742, USA.
| | | | | | | |
Collapse
|
13
|
Drake JF, Shay MA, Thongthai W, Swisdak M. Production of energetic electrons during magnetic reconnection. Phys Rev Lett 2005; 94:095001. [PMID: 15783970 DOI: 10.1103/physrevlett.94.095001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2004] [Indexed: 05/24/2023]
Abstract
The production of energetic electrons during magnetic reconnection is explored with full particle simulations and analytic analysis. Density cavities generated along separatrices bounding growing magnetic islands support parallel electric fields that act as plasma accelerators. Electrons because of their low mass are fast enough to make multiple passes through these acceleration cavities and are therefore capable of reaching relativistic energies.
Collapse
Affiliation(s)
- J F Drake
- University of Maryland, College Park, Maryland 20742, USA
| | | | | | | |
Collapse
|
14
|
Shay MA, Swisdak M. Three-species collisionless reconnection: effect of O+ on magnetotail reconnection. Phys Rev Lett 2004; 93:175001. [PMID: 15525083 DOI: 10.1103/physrevlett.93.175001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2004] [Indexed: 05/24/2023]
Abstract
The nature of collisionless reconnection in a three-species plasma composed of a heavy species, protons, and electrons is examined. In addition to the usual two length scales present in two-species reconnection, there are two additional larger length scales in the system: one associated with a "heavy whistler" which produces a large scale quadrupolar out-of-plane magnetic field, and one associated with the "heavy Alfvén" wave which can slow the outflow speed and thus the reconnection rate. The consequences for reconnection with O+ present in the magnetotail are discussed.
Collapse
Affiliation(s)
- M A Shay
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, USA.
| | | |
Collapse
|
15
|
Affiliation(s)
- M. Swisdak
- Institute for Research in Electronics and Applied Physics; University of Maryland; College Park Maryland USA
| | - B. N. Rogers
- Department of Physics; Dartmouth College; Hanover New Hampshire USA
| | - J. F. Drake
- Institute for Research in Electronics and Applied Physics; University of Maryland; College Park Maryland USA
| | - M. A. Shay
- Institute for Research in Electronics and Applied Physics; University of Maryland; College Park Maryland USA
| |
Collapse
|
16
|
Drake JF, Swisdak M, Cattell C, Shay MA, Rogers BN, Zeiler A. Formation of electron holes and particle energization during magnetic reconnection. Science 2003; 299:873-7. [PMID: 12574625 DOI: 10.1126/science.1080333] [Citation(s) in RCA: 335] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Three-dimensional particle simulations of magnetic reconnection reveal the development of turbulence driven by intense electron beams that form near the magnetic x-line and separatrices. The turbulence collapses into localized three-dimensional nonlinear structures in which the electron density is depleted. The predicted structure of these electron holes compares favorably with satellite observations at Earth's magnetopause. The birth and death of these electron holes and their associated intense electric fields lead to strong electron scattering and energization, whose understanding is critical to explaining why magnetic explosions in space release energy so quickly and produce such a large number of energetic electrons.
Collapse
Affiliation(s)
- J F Drake
- University of Maryland, College Park, MD 20742, USA.
| | | | | | | | | | | |
Collapse
|
17
|
Swisdak M, Shay M. Comment on "Creation of magnetic energy in the solar atmosphere". Phys Rev Lett 2001; 86:1662. [PMID: 11290218 DOI: 10.1103/physrevlett.86.1662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2000] [Indexed: 05/23/2023]
|