1
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Zhang Q, Guo F, Daughton W, Li H, Le A, Phan T, Desai M. Multispecies Ion Acceleration in 3D Magnetic Reconnection with Hybrid-Kinetic Simulations. PHYSICAL REVIEW LETTERS 2024; 132:115201. [PMID: 38563953 DOI: 10.1103/physrevlett.132.115201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 01/29/2024] [Indexed: 04/04/2024]
Abstract
Magnetic reconnection drives multispecies particle acceleration broadly in space and astrophysics. We perform the first 3D hybrid simulations (fluid electrons, kinetic ions) that contain sufficient scale separation to produce nonthermal heavy-ion acceleration, with fragmented flux ropes critical for accelerating all species. We demonstrate the acceleration of all ion species (up to Fe) into power-law spectra with similar indices, by a common Fermi acceleration mechanism. The upstream ion velocities influence the first Fermi reflection for injection. The subsequent onsets of Fermi acceleration are delayed for ions with lower charge-mass ratios (Q/M), until growing flux ropes magnetize them. This leads to a species-dependent maximum energy/nucleon ∝(Q/M)^{α}. These findings are consistent with in situ observations in reconnection regions, suggesting Fermi acceleration as the dominant multispecies ion acceleration mechanism.
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Affiliation(s)
- Qile Zhang
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Fan Guo
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - William Daughton
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Hui Li
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Ari Le
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Tai Phan
- Space Sciences Laboratory, University of California, Berkeley, Berkeley, California 94720, USA
| | - Mihir Desai
- Southwest Research Institute, 6220 Culebra Road, San Antonio, Texas 78238, USA and Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, Texas 78249, USA
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2
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Ji H, Yoo J, Fox W, Yamada M, Argall M, Egedal J, Liu YH, Wilder R, Eriksson S, Daughton W, Bergstedt K, Bose S, Burch J, Torbert R, Ng J, Chen LJ. Laboratory Study of Collisionless Magnetic Reconnection. SPACE SCIENCE REVIEWS 2023; 219:76. [PMID: 38023292 PMCID: PMC10651714 DOI: 10.1007/s11214-023-01024-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 11/03/2023] [Indexed: 12/01/2023]
Abstract
A concise review is given on the past two decades' results from laboratory experiments on collisionless magnetic reconnection in direct relation with space measurements, especially by the Magnetospheric Multiscale (MMS) mission. Highlights include spatial structures of electromagnetic fields in ion and electron diffusion regions as a function of upstream symmetry and guide field strength, energy conversion and partitioning from magnetic field to ions and electrons including particle acceleration, electrostatic and electromagnetic kinetic plasma waves with various wavelengths, and plasmoid-mediated multiscale reconnection. Combined with the progress in theoretical, numerical, and observational studies, the physics foundation of fast reconnection in collisionless plasmas has been largely established, at least within the parameter ranges and spatial scales that were studied. Immediate and long-term future opportunities based on multiscale experiments and space missions supported by exascale computation are discussed, including dissipation by kinetic plasma waves, particle heating and acceleration, and multiscale physics across fluid and kinetic scales.
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Affiliation(s)
- H. Ji
- Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Princeton, 08544 New Jersey USA
- Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, 08543 New Jersey USA
| | - J. Yoo
- Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, 08543 New Jersey USA
| | - W. Fox
- Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, 08543 New Jersey USA
| | - M. Yamada
- Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, 08543 New Jersey USA
| | - M. Argall
- Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, 8 College Road, Durham, 03824 New Hampshire USA
| | - J. Egedal
- Department of Physics, University of Wisconsin - Madison, 1150 University Avenue, Madison, 53706 Wisconsin USA
| | - Y.-H. Liu
- Department of Physics and Astronomy, Dartmouth College, 17 Fayerweather Hill Road, Hanover, 03755 New Hampshire USA
| | - R. Wilder
- Department of Physics, University of Texas at Arlington, 701 S. Nedderman Drive, Arlington, 76019 Texas USA
| | - S. Eriksson
- Laboratory for Atmospheric and Space Physics, University of Colorado at Boulder, 1234 Innovation Drive, Boulder, 80303 Colorado USA
| | - W. Daughton
- Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, 87545 New Mexico USA
| | - K. Bergstedt
- Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Princeton, 08544 New Jersey USA
| | - S. Bose
- Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, 08543 New Jersey USA
| | - J. Burch
- Southwest Research Institute, 6220 Culebra Road, San Antonio, 78238 Texas USA
| | - R. Torbert
- Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, 8 College Road, Durham, 03824 New Hampshire USA
| | - J. Ng
- Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, 08543 New Jersey USA
- Department of Astronomy, University of Maryland, 4296 Stadium Drive, College Park, 20742 Maryland USA
- Goddard Space Flight Center, Mail Code 130, Greenbelt, 20771 Maryland USA
| | - L.-J. Chen
- Goddard Space Flight Center, Mail Code 130, Greenbelt, 20771 Maryland USA
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3
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Oka M, Birn J, Egedal J, Guo F, Ergun RE, Turner DL, Khotyaintsev Y, Hwang KJ, Cohen IJ, Drake JF. Particle Acceleration by Magnetic Reconnection in Geospace. SPACE SCIENCE REVIEWS 2023; 219:75. [PMID: 37969745 PMCID: PMC10630319 DOI: 10.1007/s11214-023-01011-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 10/05/2023] [Indexed: 11/17/2023]
Abstract
Particles are accelerated to very high, non-thermal energies during explosive energy-release phenomena in space, solar, and astrophysical plasma environments. While it has been established that magnetic reconnection plays an important role in the dynamics of Earth's magnetosphere, it remains unclear how magnetic reconnection can further explain particle acceleration to non-thermal energies. Here we review recent progress in our understanding of particle acceleration by magnetic reconnection in Earth's magnetosphere. With improved resolutions, recent spacecraft missions have enabled detailed studies of particle acceleration at various structures such as the diffusion region, separatrix, jets, magnetic islands (flux ropes), and dipolarization front. With the guiding-center approximation of particle motion, many studies have discussed the relative importance of the parallel electric field as well as the Fermi and betatron effects. However, in order to fully understand the particle acceleration mechanism and further compare with particle acceleration in solar and astrophysical plasma environments, there is a need for further investigation of, for example, energy partition and the precise role of turbulence.
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Affiliation(s)
- Mitsuo Oka
- Space Sciences Laboratory, University of California Berkeley, 7 Gauss Way, Berkeley, 94720 CA USA
| | - Joachim Birn
- Center for Space Plasma Physics, Space Science Institute, 4765 Walnut Street, Boulder, 80301 CO USA
- Los Alamos National Laboratory, Los Alamos, 87545 NM USA
| | - Jan Egedal
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, 53706 WI USA
| | - Fan Guo
- Los Alamos National Laboratory, Los Alamos, 87545 NM USA
| | - Robert E. Ergun
- Laboratory for Atmospheric and Space Physics, University of Colorado, 1234 Innovation Drive, Boulder, 80303 CO USA
- Department of Astrophysical and Planetary Sciences, University of Colorado, 2000 Colorado Avenue, Boulder, 80309 CO USA
| | - Drew L. Turner
- The Johns Hopkins Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, 20723 MD USA
| | | | - Kyoung-Joo Hwang
- Southwest Research Institute, 6220 Culebra Road, San Antonio, 78238 TX USA
| | - Ian J. Cohen
- The Johns Hopkins Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, 20723 MD USA
| | - James F. Drake
- Department of Physics, The Institute for Physical Science and Technology and The Joint Space Science Institute, University of Maryland, College Park, 20742 MD USA
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4
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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. PHYSICAL REVIEW LETTERS 2023; 131:155101. [PMID: 37897764 DOI: 10.1103/physrevlett.131.155101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [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.
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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
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5
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Brandt PC, Provornikova E, Bale SD, Cocoros A, DeMajistre R, Dialynas K, Elliott HA, Eriksson S, Fields B, Galli A, Hill ME, Horanyi M, Horbury T, Hunziker S, Kollmann P, Kinnison J, Fountain G, Krimigis SM, Kurth WS, Linsky J, Lisse CM, Mandt KE, Magnes W, McNutt RL, Miller J, Moebius E, Mostafavi P, Opher M, Paxton L, Plaschke F, Poppe AR, Roelof EC, Runyon K, Redfield S, Schwadron N, Sterken V, Swaczyna P, Szalay J, Turner D, Vannier H, Wimmer-Schweingruber R, Wurz P, Zirnstein EJ. Future Exploration of the Outer Heliosphere and Very Local Interstellar Medium by Interstellar Probe. SPACE SCIENCE REVIEWS 2023; 219:18. [PMID: 36874191 PMCID: PMC9974711 DOI: 10.1007/s11214-022-00943-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 12/07/2022] [Indexed: 06/18/2023]
Abstract
A detailed overview of the knowledge gaps in our understanding of the heliospheric interaction with the largely unexplored Very Local Interstellar Medium (VLISM) are provided along with predictions of with the scientific discoveries that await. The new measurements required to make progress in this expanding frontier of space physics are discussed and include in-situ plasma and pick-up ion measurements throughout the heliosheath, direct sampling of the VLISM properties such as elemental and isotopic composition, densities, flows, and temperatures of neutral gas, dust and plasma, and remote energetic neutral atom (ENA) and Lyman-alpha (LYA) imaging from vantage points that can uniquely discern the heliospheric shape and bring new information on the interaction with interstellar hydrogen. The implementation of a pragmatic Interstellar Probe mission with a nominal design life to reach 375 Astronomical Units (au) with likely operation out to 550 au are reported as a result of a 4-year NASA funded mission study.
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Affiliation(s)
- P. C. Brandt
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - E. Provornikova
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - S. D. Bale
- University of California Berkeley, Berkeley, CA USA
| | - A. Cocoros
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - R. DeMajistre
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - K. Dialynas
- Office of Space Research and Technology, Academy of Athens, Athens, 10679 Greece
| | | | - S. Eriksson
- Laboratory for Atmospheric and Space Physics, University of Colorado at Boulder, Boulder, CO USA
| | - B. Fields
- University of Illinois Urbana-Champaign, Urbana, IL USA
| | - A. Galli
- University of Bern, Bern, Switzerland
| | - M. E. Hill
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - M. Horanyi
- Laboratory for Atmospheric and Space Physics, University of Colorado at Boulder, Boulder, CO USA
| | | | | | - P. Kollmann
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - J. Kinnison
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - G. Fountain
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - S. M. Krimigis
- Office of Space Research and Technology, Academy of Athens, Athens, 10679 Greece
| | | | - J. Linsky
- University of Colorado Boulder, Boulder, CO USA
| | - C. M. Lisse
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - K. E. Mandt
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - W. Magnes
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| | - R. L. McNutt
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | | | - E. Moebius
- University of New Hampshire, Durham, NH USA
| | - P. Mostafavi
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - M. Opher
- Boston University, Boston, MA USA
| | - L. Paxton
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - F. Plaschke
- Technical University Braunschweig, Braunschweig, Germany
| | - A. R. Poppe
- University of California Berkeley, Berkeley, CA USA
| | - E. C. Roelof
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - K. Runyon
- Planetary Science Institute, Tucson, AZ USA
| | | | | | | | | | - J. Szalay
- Princeton University, Princeton, NJ USA
| | - D. Turner
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | | | | | - P. Wurz
- University of Bern, Bern, Switzerland
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6
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Dong C, Wang L, Huang YM, Comisso L, Sandstrom TA, Bhattacharjee A. Reconnection-driven energy cascade in magnetohydrodynamic turbulence. SCIENCE ADVANCES 2022; 8:eabn7627. [PMID: 36475799 PMCID: PMC9728964 DOI: 10.1126/sciadv.abn7627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 10/28/2022] [Indexed: 06/17/2023]
Abstract
Magnetohydrodynamic turbulence regulates the transfer of energy from large to small scales in many astrophysical systems, including the solar atmosphere. We perform three-dimensional magnetohydrodynamic simulations with unprecedentedly large magnetic Reynolds number to reveal how rapid reconnection of magnetic field lines changes the classical paradigm of the turbulent energy cascade. By breaking elongated current sheets into chains of small magnetic flux ropes (or plasmoids), magnetic reconnection leads to a previously undiscovered range of energy cascade, where the rate of energy transfer is controlled by the growth rate of the plasmoids. As a consequence, the turbulent energy spectra steepen and attain a spectral index of -2.2 that is accompanied by changes in the anisotropy of turbulence eddies. The omnipresence of plasmoids and their consequences on, for example, solar coronal heating, can be further explored with current and future spacecraft and telescopes.
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Affiliation(s)
- Chuanfei Dong
- Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08540, USA
- Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA
| | - Liang Wang
- Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08540, USA
- Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA
| | - Yi-Min Huang
- Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08540, USA
- Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA
| | - Luca Comisso
- Department of Astronomy and Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027, USA
| | | | - Amitava Bhattacharjee
- Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08540, USA
- Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA
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7
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Sun W, Turner DL, Zhang Q, Wang S, Egedal J, Leonard T, Slavin JA, Hu Q, Cohen IJ, Genestreti K, Poh G, Gershman DJ, Smith A, Le G, Nakamura R, Giles BL, Ergun RE, Burch JL. Properties and Acceleration Mechanisms of Electrons Up To 200 keV Associated With a Flux Rope Pair and Reconnection X-Lines Around It in Earth's Plasma Sheet. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2022; 127:e2022JA030721. [PMID: 37032657 PMCID: PMC10078532 DOI: 10.1029/2022ja030721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 10/26/2022] [Accepted: 12/02/2022] [Indexed: 06/19/2023]
Abstract
The properties and acceleration mechanisms of electrons (<200 keV) associated with a pair of tailward traveling flux ropes and accompanied reconnection X-lines in Earth's plasma sheet are investigated with MMS measurements. Energetic electrons are enhanced on both boundaries and core of the flux ropes. The power-law spectra of energetic electrons near the X-lines and in flux ropes are harder than those on flux rope boundaries. Theoretical calculations show that the highest energy of adiabatic electrons is a few keV around the X-lines, tens of keV immediately downstream of the X-lines, hundreds of keV on the flux rope boundaries, and a few MeV in the flux rope cores. The X-lines cause strong energy dissipation, which may generate the energetic electron beams around them. The enhanced electron parallel temperature can be caused by the curvature-driven Fermi acceleration and the parallel electric potential. Betatron acceleration due to the magnetic field compression is strong on flux rope boundaries, which enhances energetic electrons in the perpendicular direction. Electrons can be trapped between the flux rope pair due to mirror force and parallel electric potential. Electrostatic structures in the flux rope cores correspond to potential drops up to half of the electron temperature. The energetic electrons and the electron distribution functions in the flux rope cores are suggested to be transported from other dawn-dusk directions, which is a 3-dimensional effect. The acceleration and deceleration of the Betatron and Fermi processes appear alternately indicating that the magnetic field and plasma are turbulent around the flux ropes.
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Affiliation(s)
- Weijie Sun
- Department of Climate and Space Sciences and EngineeringUniversity of MichiganAnn ArborMIUSA
| | - Drew L. Turner
- Space Exploration SectorJohns Hopkins Applied Physics LaboratoryLaurelMDUSA
| | - Qile Zhang
- Los Alamos National LaboratoryLos AlamosNMUSA
| | - Shan Wang
- Department of AstronomyUniversity of MarylandCollege ParkMDUSA
| | - Jan Egedal
- Department of PhysicsUniversity of Wisconsin‐MadisonMadisonWIUSA
| | - Trevor Leonard
- Laboratory for Atmospheric and Space PhysicsUniversity of Colorado BoulderBoulderCOUSA
| | - James A. Slavin
- Department of Climate and Space Sciences and EngineeringUniversity of MichiganAnn ArborMIUSA
| | - Qiang Hu
- Department of Space ScienceCenter for Space Plasma and Aeronomic ResearchThe University of Alabama in HuntsvilleHuntsvilleALUSA
| | - Ian J. Cohen
- Space Exploration SectorJohns Hopkins Applied Physics LaboratoryLaurelMDUSA
| | | | - Gangkai Poh
- NASA Goddard Space Flight CenterGreenbeltMDUSA
- Center for Research and Exploration in Space Sciences and Technology IICatholic University of AmericaWashingtonDCUSA
| | | | - Andrew Smith
- Mullard Space Science LaboratoryUniversity College LondonSurreyUK
- Department of Mathematics, Physics and Electrical EngineeringNorthumbria UniversityNewcastle Upon TyneUK
| | - Guan Le
- NASA Goddard Space Flight CenterGreenbeltMDUSA
| | - Rumi Nakamura
- Space Research InstituteAustrian Academy of SciencesGrazAustria
| | | | - Robert E. Ergun
- Department of Astrophysical and Planetary SciencesUniversity of Colorado BoulderBoulderCOUSA
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8
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Lemoine M. First-Principles Fermi Acceleration in Magnetized Turbulence. PHYSICAL REVIEW LETTERS 2022; 129:215101. [PMID: 36461966 DOI: 10.1103/physrevlett.129.215101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 09/02/2022] [Accepted: 09/29/2022] [Indexed: 06/17/2023]
Abstract
This Letter provides a concrete implementation of Fermi's model of particle acceleration in magnetohydrodynamic (MHD) turbulence, connecting the rate of energization to the gradients of the velocity of magnetic field lines, which it characterizes within a multifractal picture of turbulence intermittency. It then derives a transport equation in momentum space for the distribution function. This description is shown to be substantiated by a large-scale numerical simulation of strong MHD turbulence. The present general framework can be used to model particle acceleration in a variety of environments.
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Affiliation(s)
- Martin Lemoine
- Institut d'Astrophysique de Paris, CNRS-Sorbonne Université, 98 bis boulevard Arago, F-75014 Paris, France
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9
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Bolaños S, Sladkov A, Smets R, Chen SN, Grisollet A, Filippov E, Henares JL, Nastasa V, Pikuz S, Riquier R, Safronova M, Severin A, Starodubtsev M, Fuchs J. Laboratory evidence of magnetic reconnection hampered in obliquely interacting flux tubes. Nat Commun 2022; 13:6426. [PMID: 36307404 PMCID: PMC9616926 DOI: 10.1038/s41467-022-33813-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 09/30/2022] [Indexed: 11/14/2022] Open
Abstract
Magnetic reconnection can occur when two plasmas, having anti-parallel components of the magnetic field, encounter each other. In the reconnection plane, the anti-parallel component of the field is annihilated and its energy released in the plasma. Here, we investigate through laboratory experiments the reconnection between two flux tubes that are not strictly anti-parallel. Compression of the anti-parallel component of the magnetic field is observed, as well as a decrease of the reconnection efficiency. Concomitantly, we observe delayed plasma heating and enhanced particle acceleration. Three-dimensional hybrid simulations support these observations and highlight the plasma heating inhibition and reconnection efficiency reduction for these obliquely oriented flux tubes.
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Affiliation(s)
- Simon Bolaños
- LULI - CNRS, CEA, UPMC Univ Paris 06 : Sorbonne Université, Ecole Polytechnique, Institut Polytechnique de Paris, F-91128, Paris, Palaiseau cedex, France
- LPP, Sorbonne Université, CNRS, Ecole Polytechnique, F-91128, Palaiseau, France
| | - Andrey Sladkov
- Institute of Applied Physics, 46 Ulyanov Street, 603950, Nizhny Novgorod, Russia
| | - Roch Smets
- LPP, Sorbonne Université, CNRS, Ecole Polytechnique, F-91128, Palaiseau, France
| | - Sophia N Chen
- ELI-NP, Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest, Magurele, Romania
| | | | - Evgeny Filippov
- Institute of Applied Physics, 46 Ulyanov Street, 603950, Nizhny Novgorod, Russia
- Joint Institute for High Temperatures, RAS, 125412, Moscow, Russia
| | - Jose-Luis Henares
- Centre d'Etudes Nucléaires de Bordeaux Gradignan, Université de Bordeaux, CNRS-IN2P3, Route du Solarium, F-33175, Gradignan, France
| | - Viorel Nastasa
- ELI-NP, Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest, Magurele, Romania
- National Institute for Laser, Plasma and Radiation Physics, Magurele, Ilfov, Romania
| | - Sergey Pikuz
- National Research Nuclear University MEPhI, 115409, Moscow, Russia
- Joint Institute for High Temperatures, RAS, 125412, Moscow, Russia
| | | | - Maria Safronova
- Institute of Applied Physics, 46 Ulyanov Street, 603950, Nizhny Novgorod, Russia
| | - Alexandre Severin
- LULI - CNRS, CEA, UPMC Univ Paris 06 : Sorbonne Université, Ecole Polytechnique, Institut Polytechnique de Paris, F-91128, Paris, Palaiseau cedex, France
| | - Mikhail Starodubtsev
- Institute of Applied Physics, 46 Ulyanov Street, 603950, Nizhny Novgorod, Russia
| | - Julien Fuchs
- LULI - CNRS, CEA, UPMC Univ Paris 06 : Sorbonne Université, Ecole Polytechnique, Institut Polytechnique de Paris, F-91128, Paris, Palaiseau cedex, France.
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10
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Sarkango Y, Slavin JA, Jia X, DiBraccio GA, Clark GB, Sun W, Mauk BH, Kurth WS, Hospodarsky GB. Properties of Ion-Inertial Scale Plasmoids Observed by the Juno Spacecraft in the Jovian Magnetotail. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2022; 127:e2021JA030181. [PMID: 35865743 PMCID: PMC9286786 DOI: 10.1029/2021ja030181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 02/21/2022] [Accepted: 02/23/2022] [Indexed: 06/15/2023]
Abstract
We expand on previous observations of magnetic reconnection in Jupiter's magnetosphere by constructing a survey of ion-inertial scale plasmoids in the Jovian magnetotail. We developed an automated detection algorithm to identify reversals in the B θ component and performed the minimum variance analysis for each identified plasmoid to characterize its helical structure. The magnetic field observations were complemented by data collected using the Juno Waves instrument, which is used to estimate the total electron density, and the JEDI energetic particle detectors. We identified 87 plasmoids with "peak-to-peak" durations between 10 and 300 s. Thirty-one plasmoids possessed a core field and were classified as flux-ropes. The other 56 plasmoids had minimum field strength at their centers and were termed O-lines. Out of the 87 plasmoids, 58 had in situ signatures shorter than 60 s, despite the algorithm's upper limit being 300 s, suggesting that smaller plasmoids with shorter durations were more likely to be detected by Juno. We estimate the diameter of these plasmoids assuming a circular cross section and a travel speed equal to the Alfven speed in the surrounding lobes. Using the electron density inferred by Waves, we contend that these plasmoid diameters were within an order of the local ion-inertial length. Our results demonstrate that magnetic reconnection in the Jovian magnetotail occurs at ion scales like in other space environments. We show that ion-scale plasmoids would need to be released every 0.1 s or less to match the canonical 1 ton/s rate of plasma production due to Io.
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Affiliation(s)
| | | | | | | | - George B. Clark
- Johns Hopkins University – Applied Physics LaboratoryLawrelMDUSA
| | | | - Barry H. Mauk
- Johns Hopkins University – Applied Physics LaboratoryLawrelMDUSA
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11
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Yan X, Xue Z, Jiang C, Priest ER, Kliem B, Yang L, Wang J, Kong D, Song Y, Feng X, Liu Z. Fast plasmoid-mediated reconnection in a solar flare. Nat Commun 2022; 13:640. [PMID: 35110575 PMCID: PMC8810921 DOI: 10.1038/s41467-022-28269-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 01/13/2022] [Indexed: 11/09/2022] Open
Abstract
Magnetic reconnection is a multi-faceted process of energy conversion in astrophysical, space and laboratory plasmas that operates at microscopic scales but has macroscopic drivers and consequences. Solar flares present a key laboratory for its study, leaving imprints of the microscopic physics in radiation spectra and allowing the macroscopic evolution to be imaged, yet a full observational characterization remains elusive. Here we combine high resolution imaging and spectral observations of a confined solar flare at multiple wavelengths with data-constrained magnetohydrodynamic modeling to study the dynamics of the flare plasma from the current sheet to the plasmoid scale. The analysis suggests that the flare resulted from the interaction of a twisted magnetic flux rope surrounding a filament with nearby magnetic loops whose feet are anchored in chromospheric fibrils. Bright cusp-shaped structures represent the region around a reconnecting separator or quasi-separator (hyperbolic flux tube). The fast reconnection, which is relevant for other astrophysical environments, revealed plasmoids in the current sheet and separatrices and associated unresolved turbulent motions.
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Affiliation(s)
- Xiaoli Yan
- Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan, 650216, People's Republic of China.
- State Key Laboratory of Space Weather, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.
- Center for Astronomical Mega-Science, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing, 100012, People's Republic of China.
| | - Zhike Xue
- Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan, 650216, People's Republic of China
- Center for Astronomical Mega-Science, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing, 100012, People's Republic of China
| | - Chaowei Jiang
- Institute of Space Science and Applied Technology, Harbin Institute of Technology, Shenzhen, 518055, People's Republic of China.
| | - E R Priest
- School of Mathematics and Statistics, University of St Andrews, St Andrews, KY16 9SS, UK
| | - Bernhard Kliem
- Institute of Physics and Astronomy, University of Potsdam, Potsdam, 14476, Germany
| | - Liheng Yang
- Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan, 650216, People's Republic of China
- Center for Astronomical Mega-Science, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing, 100012, People's Republic of China
| | - Jincheng Wang
- Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan, 650216, People's Republic of China
- Center for Astronomical Mega-Science, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing, 100012, People's Republic of China
| | - Defang Kong
- Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan, 650216, People's Republic of China
- Center for Astronomical Mega-Science, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing, 100012, People's Republic of China
| | - Yongliang Song
- Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012, People's Republic of China
| | - Xueshang Feng
- State Key Laboratory of Space Weather, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China
| | - Zhong Liu
- Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan, 650216, People's Republic of China
- University of Chinese Academy of Sciences, Yuquan Road, Shijingshan Block, Beijing, 100049, People's Republic of China
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12
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Uzdensky DA. Relativistic Nonthermal Particle Acceleration in Two-Dimensional Collisionless Magnetic Reconnection. JOURNAL OF PLASMA PHYSICS 2022; 88:905880114. [PMID: 35241860 PMCID: PMC8886498 DOI: 10.1017/s0022377822000046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Magnetic reconnection, especially in the relativistic regime, provides an efficient mechanism for accelerating relativistic particles and thus offers an attractive physical explanation for nonthermal high-energy emission from various astrophysical sources. I present a simple analytical model that elucidates key physical processes responsible for reconnection-driven relativistic nonthermal particle acceleration (NTPA) in the large-system, plasmoid-dominated regime in two dimensions. The model aims to explain the numerically-observed dependencies of the power-law index p and high-energy cutoff γc of the resulting nonthermal particle energy spectrum f(γ) on the ambient plasma magnetization σ, and (for γc ) on the system size L. In this self-similar model, energetic particles are continuously accelerated by the out-of-plane reconnection electric field E rec until they become magnetized by the reconnected magnetic field and eventually trapped in plasmoids large enough to confine them. The model also includes diffusive Fermi acceleration by particle bouncing off rapidly moving plasmoids. I argue that the balance between electric acceleration and magnetization controls the power-law index, while trapping in plasmoids governs the cutoff, thus tying the particle energy spectrum to the plasmoid distribution.
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Affiliation(s)
- Dmitri A. Uzdensky
- Center for Integrated Plasma Studies, Physics Department, 390 UCB, University of Colorado, Boulder, CO 80309, USA
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13
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Zhang Q, Guo F, Daughton W, Li H, Li X. Efficient Nonthermal Ion and Electron Acceleration Enabled by the Flux-Rope Kink Instability in 3D Nonrelativistic Magnetic Reconnection. PHYSICAL REVIEW LETTERS 2021; 127:185101. [PMID: 34767407 DOI: 10.1103/physrevlett.127.185101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 08/16/2021] [Accepted: 09/10/2021] [Indexed: 06/13/2023]
Abstract
The relaxation of field-line tension during magnetic reconnection gives rise to a universal Fermi acceleration process involving the curvature drift of particles. However, the efficiency of this mechanism is limited by the trapping of energetic particles within flux ropes. Using 3D fully kinetic simulations, we demonstrate that the flux-rope kink instability leads to strong field-line chaos in weak-guide-field regimes where the Fermi mechanism is most efficient, thus allowing particles to transport out of flux ropes and undergo further acceleration. As a consequence, both ions and electrons develop clear power-law energy spectra that contain a significant fraction of the released energy. The low-energy bounds are determined by the injection physics, while the high-energy cutoffs are limited only by the system size. These results have strong relevance to observations of nonthermal particle acceleration in space and astrophysics.
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Affiliation(s)
- Qile Zhang
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Fan Guo
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - William Daughton
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Hui Li
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Xiaocan Li
- Dartmouth College, Hanover, New Hampshire 03755, USA
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14
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Verscharen D, Wicks RT, Alexandrova O, Bruno R, Burgess D, Chen CHK, D’Amicis R, De Keyser J, de Wit TD, Franci L, He J, Henri P, Kasahara S, Khotyaintsev Y, Klein KG, Lavraud B, Maruca BA, Maksimovic M, Plaschke F, Poedts S, Reynolds CS, Roberts O, Sahraoui F, Saito S, Salem CS, Saur J, Servidio S, Stawarz JE, Štverák Š, Told D. A Case for Electron-Astrophysics. EXPERIMENTAL ASTRONOMY 2021; 54:473-519. [PMID: 36915623 PMCID: PMC9998602 DOI: 10.1007/s10686-021-09761-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 05/07/2021] [Indexed: 06/18/2023]
Abstract
The smallest characteristic scales, at which electron dynamics determines the plasma behaviour, are the next frontier in space and astrophysical plasma research. The analysis of astrophysical processes at these scales lies at the heart of the research theme of electron-astrophysics. Electron scales are the ultimate bottleneck for dissipation of plasma turbulence, which is a fundamental process not understood in the electron-kinetic regime. In addition, plasma electrons often play an important role for the spatial transfer of thermal energy due to the high heat flux associated with their velocity distribution. The regulation of this electron heat flux is likewise not understood. By focussing on these and other fundamental electron processes, the research theme of electron-astrophysics links outstanding science questions of great importance to the fields of space physics, astrophysics, and laboratory plasma physics. In this White Paper, submitted to ESA in response to the Voyage 2050 call, we review a selection of these outstanding questions, discuss their importance, and present a roadmap for answering them through novel space-mission concepts.
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Affiliation(s)
- Daniel Verscharen
- Mullard Space Science Laboratory, University College London, Dorking, UK
- Space Science Center, University of New Hampshire, Durham, NH USA
| | - Robert T. Wicks
- Mullard Space Science Laboratory, University College London, Dorking, UK
- Department of Mathematics, Physics and Electrical Engineering, Northumbria University, Newcastle-upon-Tyne, UK
| | - Olga Alexandrova
- Laboratoire d’Études Spatiales et d’Instrumentation en Astrophysique, Observatoire de Paris-Meudon, Paris, France
| | - Roberto Bruno
- Instituto di Astrofisica e Planetologia Spaziali, INAF, Rome, Italy
| | - David Burgess
- School of Physics and Astronomy, Queen Mary University of London, London, UK
| | | | | | - Johan De Keyser
- Royal Belgian Institute for Space Aeronomy, Brussels, Belgium
| | - Thierry Dudok de Wit
- Laboratoire de Physique et Chimie de l’Environment et de l’Espace, CNRS, University of Orléans and CNES, Orléans, France
| | - Luca Franci
- School of Physics and Astronomy, Queen Mary University of London, London, UK
- Osservatorio Astrofisico di Arcetri, INAF, Firenze, Italy
| | - Jiansen He
- School of Earth and Space Sciences, Peking University, Beijing, China
| | - Pierre Henri
- Laboratoire de Physique et Chimie de l’Environment et de l’Espace, CNRS, University of Orléans and CNES, Orléans, France
- CNRS, UCA, OCA, Lagrange, Nice, France
| | - Satoshi Kasahara
- Department of Earth and Planetary Science, University of Tokyo, Tokyo, Japan
| | | | - Kristopher G. Klein
- Lunar and Planetary Laboratory and Department of Planetary Sciences, University of Arizona, Tucson, AZ USA
| | - Benoit Lavraud
- Laboratoire d’astrophysique de Bordeaux, Université de Bordeaux, CNRS, Pessac, France
- Institut de Recherche en Astrophysique et Planétologie, CNRS, UPS, CNES, Université de Toulouse, Toulouse, France
| | - Bennett A. Maruca
- Department of Physics and Astronomy, Bartol Research Institute, University of Delaware, Newark, DE USA
| | - Milan Maksimovic
- Laboratoire d’Études Spatiales et d’Instrumentation en Astrophysique, Observatoire de Paris-Meudon, Paris, France
| | | | - Stefaan Poedts
- Centre for Mathematical Plasma Astrophysics, KU Leuven, Leuven, Belgium
- Institute of Physics, University of Maria Curie-Skłodowska, Lublin, Poland
| | | | - Owen Roberts
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| | - Fouad Sahraoui
- Laboratoire de Physique des Plasmas, CNRS, École Polytechnique, Sorbonne Université, Observatoire de Paris-Meudon, Paris Saclay, Palaiseau, France
| | - Shinji Saito
- Space Environment Laboratory, National Institute of Information and Communications Technology, Tokyo, Japan
| | - Chadi S. Salem
- Space Sciences Laboratory, University of California, Berkeley, CA USA
| | - Joachim Saur
- Institut für Geophysik und Meteorologie, University of Cologne, Cologne, Germany
| | - Sergio Servidio
- Department of Physics, Università della Calabria, Rende, Italy
| | | | - Štěpán Štverák
- Astronomical Institute and Institute of Atmospheric Physics, Czech Academy of Sciences, Prague, Czech Republic
| | - Daniel Told
- Max Planck Institute for Plasma Physics, Garching, Germany
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15
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Wilson LB, Brosius AL, Gopalswamy N, Nieves‐Chinchilla T, Szabo A, Hurley K, Phan T, Kasper JC, Lugaz N, Richardson IG, Chen CHK, Verscharen D, Wicks RT, TenBarge JM. A Quarter Century of Wind Spacecraft Discoveries. REVIEWS OF GEOPHYSICS (WASHINGTON, D.C. : 1985) 2021; 59:e2020RG000714. [PMCID: PMC9285980 DOI: 10.1029/2020rg000714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 01/29/2021] [Accepted: 03/05/2021] [Indexed: 06/13/2023]
Abstract
The Wind spacecraft, launched on November 1, 1994, is a critical element in NASA’s Heliophysics System Observatory (HSO)—a fleet of spacecraft created to understand the dynamics of the Sun‐Earth system. The combination of its longevity (>25 years in service), its diverse complement of instrumentation, and high resolution and accurate measurements has led to it becoming the “standard candle” of solar wind measurements. Wind has over 55 selectable public data products with over ∼1,100 total data variables (including OMNI data products) on SPDF/CDAWeb alone. These data have led to paradigm shifting results in studies of statistical solar wind trends, magnetic reconnection, large‐scale solar wind structures, kinetic physics, electromagnetic turbulence, the Van Allen radiation belts, coronal mass ejection topology, interplanetary and interstellar dust, the lunar wake, solar radio bursts, solar energetic particles, and extreme astrophysical phenomena such as gamma‐ray bursts. This review introduces the mission and instrument suites then discusses examples of the contributions by Wind to these scientific topics that emphasize its importance to both the fields of heliophysics and astrophysics. Wind has made seminal advances to the fields of astrophysics, turbulence, kinetic physics, magnetic reconnection, and the radiation belts Wind pioneered the study of the source and evolution of solar radio emissions below 15 MHz Wind revolutionized our understanding of coronal mass ejections, their internal magnetic structure, and evolution
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Affiliation(s)
- Lynn B. Wilson
- NASA Goddard Space Flight CenterHeliophysics Science DivisionGreenbeltMDUSA
| | - Alexandra L. Brosius
- NASA Goddard Space Flight CenterHeliophysics Science DivisionGreenbeltMDUSA
- Department of Meteorology and Atmospheric ScienceThe Pennsylvania State UniversityUniversity ParkPAUSA
| | | | | | - Adam Szabo
- NASA Goddard Space Flight CenterHeliophysics Science DivisionGreenbeltMDUSA
| | - Kevin Hurley
- Space Sciences LaboratoryUniversity of CaliforniaBerkeleyCAUSA
| | - Tai Phan
- Space Sciences LaboratoryUniversity of CaliforniaBerkeleyCAUSA
| | - Justin C. Kasper
- School of Climate and Space Sciences and EngineeringUniversity of MichiganAnn ArborAnn ArborMIUSA
| | - Noé Lugaz
- Space Science CenterInstitute for the Study of EarthOceans, and SpaceUniversity of New HampshireDurhamNHUSA
- Department of PhysicsUniversity of New HampshireDurhamNHUSA
| | - Ian G. Richardson
- NASA Goddard Space Flight CenterHeliophysics Science DivisionGreenbeltMDUSA
- Department of AstronomyUniversity of MarylandCollege ParkMDUSA
| | | | - Daniel Verscharen
- Space Science CenterInstitute for the Study of EarthOceans, and SpaceUniversity of New HampshireDurhamNHUSA
- Mullard Space Science LaboratoryUniversity College LondonSurreyUK
| | - Robert T. Wicks
- Department of MathematicsPhysics and Electrical EngineeringNorthumbria University: Newcastle upon TyneTyne and WearUK
| | - Jason M. TenBarge
- University of MarylandCollege ParkMDUSA
- Department of Astrophysical SciencesPrinceton UniversityPrincetonNJUSA
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16
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Phase space transport in the interaction between shocks and plasma turbulence. Proc Natl Acad Sci U S A 2021; 118:2026764118. [PMID: 34006642 DOI: 10.1073/pnas.2026764118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The interaction of collisionless shocks with fully developed plasma turbulence is numerically investigated. Hybrid kinetic simulations, where a turbulent jet is slammed against an oblique shock, are employed to address the role of upstream turbulence on plasma transport. A technique, using coarse graining of the Vlasov equation, is proposed, showing that the particle transport strongly depends on upstream turbulence properties, such as strength and coherency. These results might be relevant for the understanding of acceleration and heating processes in space plasmas.
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17
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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. PHYSICAL REVIEW LETTERS 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] [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.
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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
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18
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Trattner KJ, Petrinec SM, Fuselier SA. The Location of Magnetic Reconnection at Earth's Magnetopause. SPACE SCIENCE REVIEWS 2021; 217:41. [PMID: 34720216 PMCID: PMC8550343 DOI: 10.1007/s11214-021-00817-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 03/08/2021] [Indexed: 06/13/2023]
Abstract
One of the major questions about magnetic reconnection is how specific solar wind and interplanetary magnetic field conditions influence where reconnection occurs at the Earth's magnetopause. There are two reconnection scenarios discussed in the literature: a) anti-parallel reconnection and b) component reconnection. Early spacecraft observations were limited to the detection of accelerated ion beams in the magnetopause boundary layer to determine the general direction of the reconnection X-line location with respect to the spacecraft. An improved view of the reconnection location at the magnetopause evolved from ionospheric emissions observed by polar-orbiting imagers. These observations and the observations of accelerated ion beams revealed that both scenarios occur at the magnetopause. Improved methodology using the time-of-flight effect of precipitating ions in the cusp regions and the cutoff velocity of the precipitating and mirroring ion populations was used to pinpoint magnetopause reconnection locations for a wide range of solar wind conditions. The results from these methodologies have been used to construct an empirical reconnection X-line model known as the Maximum Magnetic Shear model. Since this model's inception, several tests have confirmed its validity and have resulted in modifications to the model for certain solar wind conditions. This review article summarizes the observational evidence for the location of magnetic reconnection at the Earth's magnetopause, emphasizing the properties and efficacy of the Maximum Magnetic Shear Model.
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Affiliation(s)
| | | | - S. A. Fuselier
- Southwest Research Institute, San Antonio, TX USA
- University of Texas at San Antonio, San Antonio, TX USA
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19
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Li JH, Yang F, Zhou XZ, Zong QG, Artemyev AV, Rankin R, Shi Q, Yao S, Liu H, He J, Pu Z, Xiao C, Liu J, Pollock C, Le G, Burch JL. Self-consistent kinetic model of nested electron- and ion-scale magnetic cavities in space plasmas. Nat Commun 2020; 11:5616. [PMID: 33154395 PMCID: PMC7644639 DOI: 10.1038/s41467-020-19442-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Accepted: 10/15/2020] [Indexed: 12/05/2022] Open
Abstract
NASA’s Magnetospheric Multi-Scale (MMS) mission is designed to explore the proton- and electron-gyroscale kinetics of plasma turbulence where the bulk of particle acceleration and heating takes place. Understanding the nature of cross-scale structures ubiquitous as magnetic cavities is important to assess the energy partition, cascade and conversion in the plasma universe. Here, we present theoretical insight into magnetic cavities by deriving a self-consistent, kinetic theory of these coherent structures. By taking advantage of the multipoint measurements from the MMS constellation, we demonstrate that our kinetic model can utilize magnetic cavity observations by one MMS spacecraft to predict measurements from a second/third spacecraft. The methodology of “observe and predict” validates the theory we have derived, and confirms that nested magnetic cavities are self-organized plasma structures supported by trapped proton and electron populations in analogous to the classical theta-pinches in laboratory plasmas. Magnetic cavities play important roles in the energy cascade, conversion and dissipation in turbulent plasmas. Here, the authors show a theoretical insight into magnetic cavities by deriving a self-consistent, kinetic theory of these coherent structures.
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Affiliation(s)
- Jing-Huan Li
- School of Earth and Space Sciences, Peking University, 100871, Beijing, China
| | - Fan Yang
- School of Earth and Space Sciences, Peking University, 100871, Beijing, China
| | - Xu-Zhi Zhou
- School of Earth and Space Sciences, Peking University, 100871, Beijing, China.
| | - Qiu-Gang Zong
- School of Earth and Space Sciences, Peking University, 100871, Beijing, China.
| | - Anton V Artemyev
- Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA, 90095, USA.,Space Research Institute, Russian Academy of Sciences, Moscow, 117997, Russia
| | - Robert Rankin
- Department of Physics, University of Alberta, Edmonton, AB, T6G2G7, Canada
| | - Quanqi Shi
- Institute of Space Sciences, Shandong University, Weihai, 264209, China
| | - Shutao Yao
- Institute of Space Sciences, Shandong University, Weihai, 264209, China
| | - Han Liu
- School of Earth and Space Sciences, Peking University, 100871, Beijing, China
| | - Jiansen He
- School of Earth and Space Sciences, Peking University, 100871, Beijing, China
| | - Zuyin Pu
- School of Earth and Space Sciences, Peking University, 100871, Beijing, China
| | - Chijie Xiao
- School of Physics, Peking University, Beijing, 100871, China
| | - Ji Liu
- National Space Science Center, Chinese Academy of Sciences, Beijing, 100190, China
| | | | - Guan Le
- NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA
| | - James L Burch
- Southwest Research Institute, San Antonio, TX, 78238, USA
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20
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Knuth T, Glesener L. Subsecond Spikes in Fermi GBM X-Ray Flux as a Probe for Solar Flare Particle Acceleration. THE ASTROPHYSICAL JOURNAL 2020; 903:63. [PMID: 35068492 PMCID: PMC8780566 DOI: 10.3847/1538-4357/abb779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Solar flares are known to release a large amount of energy into accelerating electrons. Studying small timescale (⩽2s) fluctuations in nonthermal X-ray flux offers the opportunity to probe the nature of those acceleration mechanisms. By comparing the durations, differences in timing between energy bands, and the periodicity of these spikes against the relevant timescales called for by various acceleration mechanisms, a test for each mechanism's validity can be made. This work details the analysis of fast fluctuations in Fermi Gamma-ray Burst Monitor (Fermi GBM) data from two M9.3 class solar flares that occurred on SOL2011-07-30 and SOL2011-08-04. This study shows the usefulness of Fermi GBM data as a means of examining these small timescale spikes and presents a rigorous method of identifying, counting, and measuring the temporal properties of these subsecond X-ray spikes. In the two flares examined we found spikes to primarily occur in spans of 60-100 s in the impulsive phase. The relative spike intensity averaged between 6% and 28% when compared to the slowly varying component of the X-ray flux. The average spike durations were 0.49 and 0.38 s for the 2 flares. The spike duration distribution for the SOL2011-08-04 flare was found to follow a power law with a -1.2 ± 0.3 index. Of the three spiking intervals identified, only one was found to have a periodicity, showing significant power at the 1.7 ± 0.1 Hz frequency.
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Affiliation(s)
- Trevor Knuth
- The School of Physics and Astronomy, University of Minnesota, USA
| | - Lindsay Glesener
- The School of Physics and Astronomy, University of Minnesota, USA
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21
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Direct evidence of secondary reconnection inside filamentary currents of magnetic flux ropes during magnetic reconnection. Nat Commun 2020; 11:3964. [PMID: 32769991 PMCID: PMC7415135 DOI: 10.1038/s41467-020-17803-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 07/09/2020] [Indexed: 11/16/2022] Open
Abstract
Magnetic reconnection is a fundamental plasma process, by which magnetic energy is explosively released in the current sheet to energize charged particles and to create bi-directional Alfvénic plasma jets. Numerical simulations predicted that evolution of the reconnecting current sheet is dominated by formation and interaction of magnetic flux ropes, which finally leads to turbulence. Accordingly, most volume of the reconnecting current sheet is occupied by the ropes, and energy dissipation occurs via multiple relevant mechanisms, e.g., the parallel electric field, the rope coalescence and the rope contraction. As an essential element of the reconnecting current sheet, however, how these ropes evolve has been elusive. Here, we present direct evidence of secondary reconnection in the filamentary currents within the ropes. The observations indicate that secondary reconnection can make a significant contribution to energy conversion in the kinetic scale during turbulent reconnection. Magnetic reconnection is a fundamental plasma process of magnetic energy conversion to kinetic energy. Here, the authors show direct evidence of secondary reconnection in the filamentary currents within the flux ropes indicating a significant contribution to energy conversion in the kinetic scale during turbulent reconnection.
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22
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Electromagnetic Burst Generation during Annihilation of Magnetic Field in Relativistic Laser-Plasma Interaction. Sci Rep 2019; 9:19462. [PMID: 31857664 PMCID: PMC6923401 DOI: 10.1038/s41598-019-55976-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 11/27/2019] [Indexed: 11/29/2022] Open
Abstract
We present the results of theoretical studies of formation and evolution of the current sheet in a colliosionless plasma during magnetic reconnection in relativistic limit. Relativistic magnetic reconnection is driven by parallel laser pulses interacting with underdense plasma target. Annihilation of laser created magnetic field of opposite polarity generates strong non-stationary electric field formed in between the region with opposite polarity magnetic field accelerating charged particles within the current sheet. This laser-plasma target configuration is discussed in regard with the laboratory modeling of charged particle acceleration and gamma flash generation in astrophysics. We present the results of 3-dimensional kinetic simulations and theoretical studies on the formation and evolution of the current sheet in a collisionless plasma during magnetic field annihilation in the ultra-relativistic limit. Annihilation of oppositively directed magnetic fields driven by two laser pulses interacting with underdense plasma target is accompanied by an electromagnetic burst generation. The induced strong non-stationary longitudinal electric field accelerates charged particles within the current sheet. Properties of the laser-plasma target configuration are discussed in the context of the laboratory modeling for charged particle acceleration and gamma flash generation in astrophysics.
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23
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Gou T, Liu R, Kliem B, Wang Y, Veronig AM. The birth of a coronal mass ejection. SCIENCE ADVANCES 2019; 5:eaau7004. [PMID: 30906858 PMCID: PMC6428586 DOI: 10.1126/sciadv.aau7004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 01/28/2019] [Indexed: 06/09/2023]
Abstract
The Sun's atmosphere is frequently disrupted by coronal mass ejections (CMEs), coupled with flares and energetic particles. The coupling is usually attributed to magnetic reconnection at a vertical current sheet connecting the flare and CME, with the latter embedding a helical magnetic structure known as flux rope. However, both the origin of flux ropes and their nascent paths toward eruption remain elusive. Here, we present an observation of how a stellar-sized CME bubble evolves continuously from plasmoids, mini flux ropes that are barely resolved, within half an hour. The eruption initiates when plasmoids springing from a vertical current sheet merge into a leading plasmoid, which rises at increasing speeds and expands impulsively into the CME bubble, producing hard x-ray bursts simultaneously. This observation illuminates a complete CME evolutionary path capable of accommodating a wide variety of plasma phenomena by bridging the gap between microscale and macroscale dynamics.
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Affiliation(s)
- Tingyu Gou
- CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, University of Science and Technology of China, Hefei 230026, China
- Institute of Physics/IGAM and Kanzelhöhe Observatory, University of Graz, Universitätsplatz 5, 8010 Graz, Austria
- CAS Center for Excellence in Comparative Planetology, Hefei 230026, China
| | - Rui Liu
- CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Comparative Planetology, Hefei 230026, China
| | - Bernhard Kliem
- Institute of Physics and Astronomy, University of Potsdam, 14476 Potsdam, Germany
- Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT, UK
| | - Yuming Wang
- CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Comparative Planetology, Hefei 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Astrid M. Veronig
- Institute of Physics/IGAM and Kanzelhöhe Observatory, University of Graz, Universitätsplatz 5, 8010 Graz, Austria
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24
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Deng WT, Qu H, Huang ZY, Shi L, Tang ZY, Cao XY, Tao J. Facile synthesis of homochiral compounds integrating circularly polarized luminescence and two-photon excited fluorescence. Chem Commun (Camb) 2019; 55:2210-2213. [PMID: 30702725 DOI: 10.1039/c8cc08947g] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A pair of novel chiral one-dimensional compounds with the general formula [Cd(NO3)2L2]·THF (where L is R- or S-2,2'-bis(methoxymethoxy)-6,6'-bis(4-pyridyl)-1,1'-binaphthyl) for the first time show circularly polarized luminescence, two-photon excited fluorescence, and second harmonic generation activity.
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Affiliation(s)
- Wen-Ting Deng
- Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China.
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25
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Particle Acceleration at 5 au Associated with Turbulence and Small-scale Magnetic Flux Ropes. ACTA ACUST UNITED AC 2019. [DOI: 10.3847/1538-4357/aafcb2] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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26
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Self-consistent Energetic Particle Acceleration by Contracting and Reconnecting Small-scale Flux Ropes: The Governing Equations. ACTA ACUST UNITED AC 2018. [DOI: 10.3847/1538-4357/aad8b3] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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27
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An Unusual Energetic Particle Flux Enhancement Associated with Solar Wind Magnetic Island Dynamics. ACTA ACUST UNITED AC 2018. [DOI: 10.3847/2041-8213/aaddf6] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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28
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Galdon-Quiroga J, Garcia-Munoz M, McClements KG, Nocente M, Hoelzl M, Jacobsen AS, Orain F, Rivero-Rodriguez JF, Salewski M, Sanchis-Sanchez L, Suttrop W, Viezzer E. Beam-Ion Acceleration during Edge Localized Modes in the ASDEX Upgrade Tokamak. PHYSICAL REVIEW LETTERS 2018; 121:025002. [PMID: 30085760 DOI: 10.1103/physrevlett.121.025002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 04/09/2018] [Indexed: 06/08/2023]
Abstract
The acceleration of beam ions during edge localized modes (ELMs) in a tokamak is observed for the first time through direct measurements of fast-ion losses in low collisionality plasmas. The accelerated beam-ion population exhibits well-localized velocity-space structures which are revealed by means of tomographic inversion of the measurement, showing energy gains of the order of tens of keV. This suggests that the ion acceleration results from a resonant interaction between the beam ions and parallel electric fields arising during the ELM. Orbit simulations are carried out to identify the mode-particle resonances responsible for the energy gain in the particle phase space. The observation motivates the incorporation of a kinetic description of fast particles in ELM models and may contribute to a better understanding of the mechanisms responsible for particle acceleration, ubiquitous in astrophysical and space plasmas.
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Affiliation(s)
- J Galdon-Quiroga
- Department of Atomic, Molecular and Nuclear Physics, University of Seville, 41012 Seville, Spain
- Centro Nacional de Aceleradores (CNA), Universidad de Sevilla, Junta de Andalucia, Consejo Superior de Investigaciones Cientificas (CSIC), Parque Cientifico y Tecnologico Cartuja, c/Thomas Alva Edison, 7 41092 Seville, Spain
| | - M Garcia-Munoz
- Department of Atomic, Molecular and Nuclear Physics, University of Seville, 41012 Seville, Spain
- Centro Nacional de Aceleradores (CNA), Universidad de Sevilla, Junta de Andalucia, Consejo Superior de Investigaciones Cientificas (CSIC), Parque Cientifico y Tecnologico Cartuja, c/Thomas Alva Edison, 7 41092 Seville, Spain
| | - K G McClements
- CCFE, Culham Science Centre, Abingdon OX14 3DB, United Kingdom
| | - M Nocente
- Dipartimento di Fisica G Occhialini, Universita di Milano-Bicocca, Milano, Italy
| | - M Hoelzl
- Max Planck Institute for Plasma Physics, Boltzmannstrasse, 2 85748 Garching bei Munchen, Germany
| | - A S Jacobsen
- Max Planck Institute for Plasma Physics, Boltzmannstrasse, 2 85748 Garching bei Munchen, Germany
| | - F Orain
- Max Planck Institute for Plasma Physics, Boltzmannstrasse, 2 85748 Garching bei Munchen, Germany
| | - J F Rivero-Rodriguez
- Centro Nacional de Aceleradores (CNA), Universidad de Sevilla, Junta de Andalucia, Consejo Superior de Investigaciones Cientificas (CSIC), Parque Cientifico y Tecnologico Cartuja, c/Thomas Alva Edison, 7 41092 Seville, Spain
- Department of Mechanical Engineering and Manufacturing, University of Seville, Camino de los Descubrimientos s/n, 41092 Seville, Spain
| | - M Salewski
- Department of Physics, Technical University of Denmark, Kongens Lyngby, Denmark
| | - L Sanchis-Sanchez
- Department of Atomic, Molecular and Nuclear Physics, University of Seville, 41012 Seville, Spain
- Centro Nacional de Aceleradores (CNA), Universidad de Sevilla, Junta de Andalucia, Consejo Superior de Investigaciones Cientificas (CSIC), Parque Cientifico y Tecnologico Cartuja, c/Thomas Alva Edison, 7 41092 Seville, Spain
| | - W Suttrop
- Max Planck Institute for Plasma Physics, Boltzmannstrasse, 2 85748 Garching bei Munchen, Germany
| | - E Viezzer
- Department of Atomic, Molecular and Nuclear Physics, University of Seville, 41012 Seville, Spain
- Centro Nacional de Aceleradores (CNA), Universidad de Sevilla, Junta de Andalucia, Consejo Superior de Investigaciones Cientificas (CSIC), Parque Cientifico y Tecnologico Cartuja, c/Thomas Alva Edison, 7 41092 Seville, Spain
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29
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Abstract
Magnetic reconnection in the solar corona is thought to be unstable with the formation of multiple interacting plasmoids, and previous studies have shown that plasmoid dynamics can trigger MHD waves of different modes propagating outward from the reconnection site. However, variations in plasma parameters and magnetic field strength in the vicinity of a coronal reconnection site may lead to wave reflection and mode conversion. In this paper we investigate the reflection and refraction of fast magnetoacoustic waves near a reconnection site. Under a justified assumption of an analytically specified Alfvén speed profile, we derive and solve analytically the full wave equation governing the propagation of fast-mode waves in a non-uniform background plasma without recourse to the small wavelength approximation. We show that the waves undergo reflection near the reconnection current sheet due to the Alfvén speed gradient and that the reflection efficiency depends on the plasma-β parameter, as well as on the wave frequency. In particular, we find that waves are reflected more efficiently near reconnection sites in a low-β plasma, which is typical under solar coronal conditions. Also, the reflection is larger for lower-frequency waves while high-frequency waves propagate outward from the reconnection region almost without the reflection. We discuss the implications of efficient wave reflection near magnetic reconnection sites in strongly magnetized coronal plasma for particle acceleration, and also the effect this might have on first ionization potential (FIP) fractionation by the ponderomotive force of these waves in the chromosphere.
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30
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Structured Slow Solar Wind Variability: Streamer-blob Flux Ropes and Torsional Alfvén Waves. ACTA ACUST UNITED AC 2018. [DOI: 10.3847/1538-4357/aabc08] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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31
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Yi L, Shen B, Pukhov A, Fülöp T. Relativistic magnetic reconnection driven by a laser interacting with a micro-scale plasma slab. Nat Commun 2018; 9:1601. [PMID: 29686280 PMCID: PMC5913235 DOI: 10.1038/s41467-018-04065-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 03/30/2018] [Indexed: 11/26/2022] Open
Abstract
Magnetic reconnection (MR) is a fundamental plasma process associated with conversion of the magnetic field energy into kinetic plasma energy, which is invoked to explain many non-thermal signatures in astrophysical events. Here we demonstrate that ultrafast relativistic MR in a magnetically dominated regime can be triggered by a readily available (TW-mJ-class) laser interacting with a micro-scale plasma slab. Three-dimensional (3D) particle-in-cell (PIC) simulations show that when the electrons beams excited on both sides of the slab approach the end of the plasma, MR occurs and it gives rise to efficient energy dissipation that leads to the emission of relativistic electron jets with cut-off energy ~12 MeV. The proposed scenario allows for accessing an unprecedented regime of MR in the laboratory, and may lead to experimental studies that can provide insight into open questions such as reconnection rate and particle acceleration in relativistic MR. Plasma releases magnetic energy by magnetic reconnection but the clear evidence of this phenomenon in relativistic regime is still lacking. Here the authors present a scheme for laboratory observation of the relativistic magnetic reconnection driven by laser-produced energetic electrons in the plasma.
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Affiliation(s)
- Longqing Yi
- Department of Physics, Chalmers University of Technology, 41296, Gothenburg, Sweden. .,State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P.O. Box 800-211, 201800, Shanghai, China.
| | - Baifei Shen
- Department of Physics, Shanghai Normal University, 200234, Shanghai, China
| | - Alexander Pukhov
- Institut für Theoretische Physik I, Heinrich-Heine-Universität Düsseldorf, 40225, Düsseldorf, Germany
| | - Tünde Fülöp
- Department of Physics, Chalmers University of Technology, 41296, Gothenburg, Sweden
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32
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Kumar P, Karpen JT, Antiochos SK, Wyper PF, Devore CR, Deforest CE. EVIDENCE FOR THE MAGNETIC BREAKOUT MODEL IN AN EQUATORIAL CORONAL-HOLE JET. THE ASTROPHYSICAL JOURNAL 2018; 854:155. [PMID: 33867543 PMCID: PMC8051205 DOI: 10.3847/1538-4357/aaab4f] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Small, impulsive jets commonly occur throughout the solar corona, but are especially visible in coronal holes. Evidence is mounting that jets are part of a continuum of eruptions that extends to much larger coronal mass ejections and eruptive flares. Because coronal-hole jets originate in relatively simple magnetic structures, they offer an ideal testbed for theories of energy buildup and release in the full range of solar eruptions. We analyzed an equatorial coronal-hole jet observed by SDO/AIA on 09 January 2014, in which the magnetic-field structure was consistent with the embedded-bipole topology that we identified and modeled previously as an origin of coronal jets. In addition, this event contained a mini-filament, which led to important insights into the energy storage and release mechanisms. SDO/HMI magnetograms revealed footpoint motions in the primary minority-polarity region at the eruption site, but show negligible flux emergence or cancellation for at least 16 hours before the eruption. Therefore, the free energy powering this jet probably came from magnetic shear concentrated at the polarity inversion line within the embedded bipole. We find that the observed activity sequence and its interpretation closely match the predictions of the breakout jet model, strongly supporting the hypothesis that the breakout model can explain solar eruptions on a wide range of scales.
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Affiliation(s)
- Pankaj Kumar
- Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA
| | - Judith T Karpen
- Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA
| | - Spiro K Antiochos
- Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA
| | - Peter F Wyper
- Department of Mathematical Sciences, Durham University, Durham DH1 3LE, UK and
| | - C Richard Devore
- Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA
| | - Craig E Deforest
- Southwest Research Institute, 1050 Walnut Street, Boulder, CO, USA
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33
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Zhou M, Berchem J, Walker RJ, El-Alaoui M, Deng X, Cazzola E, Lapenta G, Goldstein ML, Paterson WR, Pang Y, Ergun RE, Lavraud B, Liang H, Russell CT, Strangeway RJ, Zhao C, Giles BL, Pollock CJ, Lindqvist PA, Marklund G, Wilder FD, Khotyaintsev YV, Torbert RB, Burch JL. Coalescence of Macroscopic Flux Ropes at the Subsolar Magnetopause: Magnetospheric Multiscale Observations. PHYSICAL REVIEW LETTERS 2017; 119:055101. [PMID: 28949734 DOI: 10.1103/physrevlett.119.055101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Indexed: 06/07/2023]
Abstract
We report unambiguous in situ observation of the coalescence of macroscopic flux ropes by the magnetospheric multiscale (MMS) mission. Two coalescing flux ropes with sizes of ∼1 R_{E} were identified at the subsolar magnetopause by the occurrence of an asymmetric quadrupolar signature in the normal component of the magnetic field measured by the MMS spacecraft. An electron diffusion region (EDR) with a width of four local electron inertial lengths was embedded within the merging current sheet. The EDR was characterized by an intense parallel electric field, significant energy dissipation, and suprathermal electrons. Although the electrons were organized by a large guide field, the small observed electron pressure nongyrotropy may be sufficient to support a significant fraction of the parallel electric field within the EDR. Since the flux ropes are observed in the exhaust region, we suggest that secondary EDRs are formed further downstream of the primary reconnection line between the magnetosheath and magnetospheric fields.
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Affiliation(s)
- M Zhou
- Department of Physics and Astronomy, UCLA, Los Angeles 90095, California, USA
| | - J Berchem
- Department of Physics and Astronomy, UCLA, Los Angeles 90095, California, USA
| | - R J Walker
- Department of Earth, Planetary, and Space Sciences, UCLA, Los Angeles 90095, California, USA
| | - M El-Alaoui
- Department of Physics and Astronomy, UCLA, Los Angeles 90095, California, USA
| | - X Deng
- Nanchang University, Nanchang 330031, People's Republic of China
| | - E Cazzola
- Centre for Plasma Astrophysics, Department of Mathematics, Katholieke Universiteit, Leuven 3001, Belgium
| | - G Lapenta
- Centre for Plasma Astrophysics, Department of Mathematics, Katholieke Universiteit, Leuven 3001, Belgium
| | - M L Goldstein
- NASA, Goddard Space Flight Center, Greenbelt 20771, Maryland, USA
- Space Science Institute, Boulder 80301, Colorado, USA
| | - W R Paterson
- NASA, Goddard Space Flight Center, Greenbelt 20771, Maryland, USA
| | - Y Pang
- Nanchang University, Nanchang 330031, People's Republic of China
| | - R E Ergun
- University of Colorado LASP, Boulder 80303, Colorado, USA
| | - B Lavraud
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse, CNRS, UPS, CNES, Toulouse 31028, France
| | - H Liang
- Department of Physics and Astronomy, UCLA, Los Angeles 90095, California, USA
| | - C T Russell
- Department of Earth, Planetary, and Space Sciences, UCLA, Los Angeles 90095, California, USA
| | - R J Strangeway
- Department of Earth, Planetary, and Space Sciences, UCLA, Los Angeles 90095, California, USA
| | - C Zhao
- Department of Earth, Planetary, and Space Sciences, UCLA, Los Angeles 90095, California, USA
| | - B L Giles
- NASA, Goddard Space Flight Center, Greenbelt 20771, Maryland, USA
| | - C J Pollock
- NASA, Goddard Space Flight Center, Greenbelt 20771, Maryland, USA
| | - P-A Lindqvist
- Royal Institute of Technology, Stockholm SE-11428, Sweden
| | - G Marklund
- Royal Institute of Technology, Stockholm SE-11428, Sweden
| | - F D Wilder
- University of Colorado LASP, Boulder 80303, Colorado, USA
| | | | - R B Torbert
- University of New Hampshire, Durham, New Hampshire 03824, USA
| | - J L Burch
- Southwest Research Institute, San Antonio Texas 78238, USA
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34
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Isliker H, Vlahos L, Constantinescu D. Fractional Transport in Strongly Turbulent Plasmas. PHYSICAL REVIEW LETTERS 2017; 119:045101. [PMID: 29341784 DOI: 10.1103/physrevlett.119.045101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Indexed: 06/07/2023]
Abstract
We analyze statistically the energization of particles in a large scale environment of strong turbulence that is fragmented into a large number of distributed current filaments. The turbulent environment is generated through strongly perturbed, 3D, resistive magnetohydrodynamics simulations, and it emerges naturally from the nonlinear evolution, without a specific reconnection geometry being set up. Based on test-particle simulations, we estimate the transport coefficients in energy space for use in the classical Fokker-Planck (FP) equation, and we show that the latter fails to reproduce the simulation results. The reason is that transport in energy space is highly anomalous (strange), the particles perform Levy flights, and the energy distributions show extended power-law tails. Newly then, we motivate the use and derive the specific form of a fractional transport equation (FTE), we determine its parameters and the order of the fractional derivatives from the simulation data, and we show that the FTE is able to reproduce the high energy part of the simulation data very well. The procedure for determining the FTE parameters also makes clear that it is the analysis of the simulation data that allows us to make the decision whether a classical FP equation or a FTE is appropriate.
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Affiliation(s)
- Heinz Isliker
- Department of Physics, Aristotle University of Thessaloniki, GR-52124 Thessaloniki, Greece
| | - Loukas Vlahos
- Department of Physics, Aristotle University of Thessaloniki, GR-52124 Thessaloniki, Greece
| | - Dana Constantinescu
- Department of Applied Mathematics, University of Craiova, RO-1100 Craiova, Romania
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35
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Howes GG. A prospectus on kinetic heliophysics. PHYSICS OF PLASMAS 2017; 24:055907. [PMID: 29104421 PMCID: PMC5648573 DOI: 10.1063/1.4983993] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 05/01/2017] [Indexed: 05/29/2023]
Abstract
Under the low density and high temperature conditions typical of heliospheric plasmas, the macroscopic evolution of the heliosphere is strongly affected by the kinetic plasma physics governing fundamental microphysical mechanisms. Kinetic turbulence, collisionless magnetic reconnection, particle acceleration, and kinetic instabilities are four poorly understood, grand-challenge problems that lie at the new frontier of kinetic heliophysics. The increasing availability of high cadence and high phase-space resolution measurements of particle velocity distributions by current and upcoming spacecraft missions and of massively parallel nonlinear kinetic simulations of weakly collisional heliospheric plasmas provides the opportunity to transform our understanding of these kinetic mechanisms through the full utilization of the information contained in the particle velocity distributions. Several major considerations for future investigations of kinetic heliophysics are examined. Turbulent dissipation followed by particle heating is highlighted as an inherently two-step process in weakly collisional plasmas, distinct from the more familiar case in fluid theory. Concerted efforts must be made to tackle the big-data challenge of visualizing the high-dimensional (3D-3V) phase space of kinetic plasma theory through physics-based reductions. Furthermore, the development of innovative analysis methods that utilize full velocity-space measurements, such as the field-particle correlation technique, will enable us to gain deeper insight into these four grand-challenge problems of kinetic heliophysics. A systems approach to tackle the multi-scale problem of heliophysics through a rigorous connection between the kinetic physics at microscales and the self-consistent evolution of the heliosphere at macroscales will propel the field of kinetic heliophysics into the future.
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Affiliation(s)
- Gregory G Howes
- Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, USA
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36
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Goyon C, Pollock BB, Turnbull DP, Hazi A, Divol L, Farmer WA, Haberberger D, Javedani J, Johnson AJ, Kemp A, Levy MC, Grant Logan B, Mariscal DA, Landen OL, Patankar S, Ross JS, Rubenchik AM, Swadling GF, Williams GJ, Fujioka S, Law KFF, Moody JD. Ultrafast probing of magnetic field growth inside a laser-driven solenoid. Phys Rev E 2017; 95:033208. [PMID: 28415195 DOI: 10.1103/physreve.95.033208] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Indexed: 11/07/2022]
Abstract
We report on the detection of the time-dependent B-field amplitude and topology in a laser-driven solenoid. The B-field inferred from both proton deflectometry and Faraday rotation ramps up linearly in time reaching 210 ± 35 T at the end of a 0.75-ns laser drive with 1 TW at 351 nm. A lumped-element circuit model agrees well with the linear rise and suggests that the blow-off plasma screens the field between the plates leading to an increased plate capacitance that converts the laser-generated hot-electron current into a voltage source that drives current through the solenoid. ALE3D modeling shows that target disassembly and current diffusion may limit the B-field increase for longer laser drive. Scaling of these experimental results to a National Ignition Facility (NIF) hohlraum target size (∼0.2cm^{3}) indicates that it is possible to achieve several tens of Tesla.
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Affiliation(s)
- C Goyon
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - B B Pollock
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - D P Turnbull
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - A Hazi
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - L Divol
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - W A Farmer
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - D Haberberger
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - J Javedani
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - A J Johnson
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - A Kemp
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - M C Levy
- Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - B Grant Logan
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - D A Mariscal
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - O L Landen
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - S Patankar
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - J S Ross
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - A M Rubenchik
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - G F Swadling
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - G J Williams
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - S Fujioka
- Institute of Laser Engineering, Osaka University, Suita, Osaka 565-0871, Japan
| | - K F F Law
- Institute of Laser Engineering, Osaka University, Suita, Osaka 565-0871, Japan
| | - J D Moody
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
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37
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The Secret Lives of Cepheids:δCep—The Prototype of a New Class of Pulsating X-Ray Variable Stars*. ACTA ACUST UNITED AC 2017. [DOI: 10.3847/1538-4357/aa6159] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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38
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THE ROLE OF KELVIN–HELMHOLTZ INSTABILITY FOR PRODUCING LOOP-TOP HARD X-RAY SOURCES IN SOLAR FLARES. ACTA ACUST UNITED AC 2016. [DOI: 10.3847/1538-4357/833/1/36] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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39
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Zweibel EG, Yamada M. Perspectives on magnetic reconnection. Proc Math Phys Eng Sci 2016; 472:20160479. [PMID: 28119547 PMCID: PMC5247523 DOI: 10.1098/rspa.2016.0479] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 10/31/2016] [Indexed: 11/12/2022] Open
Abstract
Magnetic reconnection is a topological rearrangement of magnetic field that occurs on time scales much faster than the global magnetic diffusion time. Since the field lines break on microscopic scales but energy is stored and the field is driven on macroscopic scales, reconnection is an inherently multi-scale process that often involves both magnetohydrodynamic (MHD) and kinetic phenomena. In this article, we begin with the MHD point of view and then describe the dynamics and energetics of reconnection using a two-fluid formulation. We also focus on the respective roles of global and local processes and how they are coupled. We conclude that the triggers for reconnection are mostly global, that the key energy conversion and dissipation processes are either local or global, and that the presence of a continuum of scales coupled from microscopic to macroscopic may be the most likely path to fast reconnection.
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Affiliation(s)
- Ellen G Zweibel
- Departments of Astronomy and Physics, University of Wisconsin-Madison, Madison, WI, USA; Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ, USA
| | - Masaaki Yamada
- Departments of Astronomy and Physics, University of Wisconsin-Madison, Madison, WI, USA; Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ, USA
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Desai M, Giacalone J. Large gradual solar energetic particle events. LIVING REVIEWS IN SOLAR PHYSICS 2016; 13:3. [PMID: 32355890 PMCID: PMC7175685 DOI: 10.1007/s41116-016-0002-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 11/13/2015] [Indexed: 05/24/2023]
Abstract
Solar energetic particles, or SEPs, from suprathermal (few keV) up to relativistic ( ∼ few GeV) energies are accelerated near the Sun in at least two ways: (1) by magnetic reconnection-driven processes during solar flares resulting in impulsive SEPs, and (2) at fast coronal-mass-ejection-driven shock waves that produce large gradual SEP events. Large gradual SEP events are of particular interest because the accompanying high-energy ( > 10 s MeV) protons pose serious radiation threats to human explorers living and working beyond low-Earth orbit and to technological assets such as communications and scientific satellites in space. However, a complete understanding of these large SEP events has eluded us primarily because their properties, as observed in Earth orbit, are smeared due to mixing and contributions from many important physical effects. This paper provides a comprehensive review of the current state of knowledge of these important phenomena, and summarizes some of the key questions that will be addressed by two upcoming missions-NASA's Solar Probe Plus and ESA's Solar Orbiter. Both of these missions are designed to directly and repeatedly sample the near-Sun environments where interplanetary scattering and transport effects are significantly reduced, allowing us to discriminate between different acceleration sites and mechanisms and to isolate the contributions of numerous physical processes occurring during large SEP events.
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Affiliation(s)
- Mihir Desai
- Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238 USA
| | - Joe Giacalone
- Department of Planetary Sciences, University of Arizona, Tucson, AZ 85721 USA
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Olson J, Egedal J, Greess S, Myers R, Clark M, Endrizzi D, Flanagan K, Milhone J, Peterson E, Wallace J, Weisberg D, Forest CB. Experimental Demonstration of the Collisionless Plasmoid Instability below the Ion Kinetic Scale during Magnetic Reconnection. PHYSICAL REVIEW LETTERS 2016; 116:255001. [PMID: 27391729 DOI: 10.1103/physrevlett.116.255001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Indexed: 06/06/2023]
Abstract
The spontaneous formation of magnetic islands is observed in driven, antiparallel magnetic reconnection on the Terrestrial Reconnection Experiment. We here provide direct experimental evidence that the plasmoid instability is active at the electron scale inside the ion diffusion region in a low collisional regime. The experiments show the island formation occurs at a smaller system size than predicted by extended magnetohydrodynamics or fully collisionless simulations. This more effective seeding of magnetic islands emphasizes their importance to reconnection in naturally occurring 3D plasmas.
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Affiliation(s)
- J Olson
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA
| | - J Egedal
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA
| | - S Greess
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA
| | - R Myers
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA
| | - M Clark
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA
| | - D Endrizzi
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA
| | - K Flanagan
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA
| | - J Milhone
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA
| | - E Peterson
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA
| | - J Wallace
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA
| | - D Weisberg
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA
| | - C B Forest
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA
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Ergun RE, Goodrich KA, Wilder FD, Holmes JC, Stawarz JE, Eriksson S, Sturner AP, Malaspina DM, Usanova ME, Torbert RB, Lindqvist PA, Khotyaintsev Y, Burch JL, Strangeway RJ, Russell CT, Pollock CJ, Giles BL, Hesse M, Chen LJ, Lapenta G, Goldman MV, Newman DL, Schwartz SJ, Eastwood JP, Phan TD, Mozer FS, Drake J, Shay MA, Cassak PA, Nakamura R, Marklund G. Magnetospheric Multiscale Satellites Observations of Parallel Electric Fields Associated with Magnetic Reconnection. PHYSICAL REVIEW LETTERS 2016; 116:235102. [PMID: 27341241 DOI: 10.1103/physrevlett.116.235102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Indexed: 06/06/2023]
Abstract
We report observations from the Magnetospheric Multiscale satellites of parallel electric fields (E_{∥}) associated with magnetic reconnection in the subsolar region of the Earth's magnetopause. E_{∥} events near the electron diffusion region have amplitudes on the order of 100 mV/m, which are significantly larger than those predicted for an antiparallel reconnection electric field. This Letter addresses specific types of E_{∥} events, which appear as large-amplitude, near unipolar spikes that are associated with tangled, reconnected magnetic fields. These E_{∥} events are primarily in or near a current layer near the separatrix and are interpreted to be double layers that may be responsible for secondary reconnection in tangled magnetic fields or flux ropes. These results are telling of the three-dimensional nature of magnetopause reconnection and indicate that magnetopause reconnection may be often patchy and/or drive turbulence along the separatrix that results in flux ropes and/or tangled magnetic fields.
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Affiliation(s)
- R E Ergun
- Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, Colorado 80303, USA
- Laboratory of Atmospheric and Space Sciences, University of Colorado, Boulder, Colorado 80303, USA
| | - K A Goodrich
- Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, Colorado 80303, USA
- Laboratory of Atmospheric and Space Sciences, University of Colorado, Boulder, Colorado 80303, USA
| | - F D Wilder
- Laboratory of Atmospheric and Space Sciences, University of Colorado, Boulder, Colorado 80303, USA
| | - J C Holmes
- Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, Colorado 80303, USA
- Laboratory of Atmospheric and Space Sciences, University of Colorado, Boulder, Colorado 80303, USA
| | - J E Stawarz
- Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, Colorado 80303, USA
- Laboratory of Atmospheric and Space Sciences, University of Colorado, Boulder, Colorado 80303, USA
| | - S Eriksson
- Laboratory of Atmospheric and Space Sciences, University of Colorado, Boulder, Colorado 80303, USA
| | - A P Sturner
- Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, Colorado 80303, USA
- Laboratory of Atmospheric and Space Sciences, University of Colorado, Boulder, Colorado 80303, USA
| | - D M Malaspina
- Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, Colorado 80303, USA
| | - M E Usanova
- Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, Colorado 80303, USA
| | - R B Torbert
- University of New Hampshire, Durham, New Hampshire 03824, USA
- Southwest Research Institute, San Antonio, Texas 78238, USA
| | - P-A Lindqvist
- KTH Royal Institute of Technology, Stockholm, Sweden
| | - Y Khotyaintsev
- Swedish Institute of Space Physics (Uppsala), Uppsala, Sweden
| | - J L Burch
- Southwest Research Institute, San Antonio, Texas 78238, USA
| | - R J Strangeway
- University of California, Los Angeles, Los Angeles, California 90095, USA
| | - C T Russell
- University of California, Los Angeles, Los Angeles, California 90095, USA
| | - C J Pollock
- NASA, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - B L Giles
- NASA, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - M Hesse
- NASA, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - L J Chen
- University of Maryland, College Park, Maryland 20742, USA
| | - G Lapenta
- Leuven Universiteit, Leuven, Belgium
| | - M V Goldman
- Department of Physics, University of Colorado, Boulder, Colorado 80303, USA
| | - D L Newman
- Department of Physics, University of Colorado, Boulder, Colorado 80303, USA
| | - S J Schwartz
- Laboratory of Atmospheric and Space Sciences, University of Colorado, Boulder, Colorado 80303, USA
- The Blackett Laboratory, Imperial College London, United Kingdom
| | - J P Eastwood
- The Blackett Laboratory, Imperial College London, United Kingdom
| | - T D Phan
- Space Sciences Laboratory, University of California, Berkeley, California 94720, USA
| | - F S Mozer
- Space Sciences Laboratory, University of California, Berkeley, California 94720, USA
| | - J Drake
- University of Maryland, College Park, Maryland 20742, USA
| | - M A Shay
- University of Delaware, Newark, Delaware 19716, USA
| | - P A Cassak
- West Virginia University, Morgantown, West Virginia 26506, USA
| | - R Nakamura
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| | - G Marklund
- KTH Royal Institute of Technology, Stockholm, Sweden
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Eastwood JP, Phan TD, Cassak PA, Gershman DJ, Haggerty C, Malakit K, Shay MA, Mistry R, Øieroset M, Russell CT, Slavin JA, Argall MR, Avanov LA, Burch JL, Chen LJ, Dorelli JC, Ergun RE, Giles BL, Khotyaintsev Y, Lavraud B, Lindqvist PA, Moore TE, Nakamura R, Paterson W, Pollock C, Strangeway RJ, Torbert RB, Wang S. Ion-scale secondary flux ropes generated by magnetopause reconnection as resolved by MMS. GEOPHYSICAL RESEARCH LETTERS 2016; 43:4716-4724. [PMID: 27635105 PMCID: PMC5001194 DOI: 10.1002/2016gl068747] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 04/28/2016] [Accepted: 04/29/2016] [Indexed: 06/06/2023]
Abstract
New Magnetospheric Multiscale (MMS) observations of small-scale (~7 ion inertial length radius) flux transfer events (FTEs) at the dayside magnetopause are reported. The 10 km MMS tetrahedron size enables their structure and properties to be calculated using a variety of multispacecraft techniques, allowing them to be identified as flux ropes, whose flux content is small (~22 kWb). The current density, calculated using plasma and magnetic field measurements independently, is found to be filamentary. Intercomparison of the plasma moments with electric and magnetic field measurements reveals structured non-frozen-in ion behavior. The data are further compared with a particle-in-cell simulation. It is concluded that these small-scale flux ropes, which are not seen to be growing, represent a distinct class of FTE which is generated on the magnetopause by secondary reconnection.
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Affiliation(s)
| | - T. D. Phan
- Space Sciences LaboratoryUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - P. A. Cassak
- Department of Physics and AstronomyWest Virginia UniversityMorgantownWest VirginiaUSA
| | - D. J. Gershman
- NASA Goddard Space Flight CenterGreenbeltMarylandUSA
- Department of AstronomyUniversity of MarylandCollege ParkMarylandUSA
| | - C. Haggerty
- Department of Physics and AstronomyUniversity of DelawareNewarkDelawareUSA
| | - K. Malakit
- Department of PhysicsMahidol UniversityBangkokThailand
| | - M. A. Shay
- Department of Physics and AstronomyUniversity of DelawareNewarkDelawareUSA
| | - R. Mistry
- Blackett LaboratoryImperial College LondonLondonUK
| | - M. Øieroset
- Space Sciences LaboratoryUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - C. T. Russell
- Department of Earth, Planetary and Space SciencesUniversity of CaliforniaLos AngelesCaliforniaUSA
| | - J. A. Slavin
- Department of Climate and Space Sciences and EngineeringUniversity of MichiganAnn ArborMichiganUSA
| | - M. R. Argall
- Institute for the Study of Earth, Oceans and SpaceUniversity of New HampshireDurhamNew HampshireUSA
| | - L. A. Avanov
- NASA Goddard Space Flight CenterGreenbeltMarylandUSA
- Department of AstronomyUniversity of MarylandCollege ParkMarylandUSA
| | - J. L. Burch
- Southwest Research InstituteSan AntonioTexasUSA
| | - L. J. Chen
- NASA Goddard Space Flight CenterGreenbeltMarylandUSA
- Department of AstronomyUniversity of MarylandCollege ParkMarylandUSA
| | - J. C. Dorelli
- NASA Goddard Space Flight CenterGreenbeltMarylandUSA
| | - R. E. Ergun
- Laboratory for Atmospheric and Space PhysicsUniversity of Colorado BoulderBoulderColoradoUSA
| | - B. L. Giles
- NASA Goddard Space Flight CenterGreenbeltMarylandUSA
| | | | - B. Lavraud
- Institut de Recherche en Astrophysique et PlanétologieUniversité de ToulouseToulouseFrance
- Centre National de la Recherche Scientifique, UMR 5277ToulouseFrance
| | - P. A. Lindqvist
- School of Electrical EngineeringRoyal Institute of TechnologyStockholmSweden
| | - T. E. Moore
- NASA Goddard Space Flight CenterGreenbeltMarylandUSA
| | - R. Nakamura
- Space Research InstituteAustrian Academy of SciencesGrazAustria
| | - W. Paterson
- NASA Goddard Space Flight CenterGreenbeltMarylandUSA
| | | | - R. J. Strangeway
- Department of Earth, Planetary and Space SciencesUniversity of CaliforniaLos AngelesCaliforniaUSA
| | - R. B. Torbert
- Institute for the Study of Earth, Oceans and SpaceUniversity of New HampshireDurhamNew HampshireUSA
- Southwest Research InstituteSan AntonioTexasUSA
| | - S. Wang
- NASA Goddard Space Flight CenterGreenbeltMarylandUSA
- Department of AstronomyUniversity of MarylandCollege ParkMarylandUSA
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Totorica SR, Abel T, Fiuza F. Nonthermal Electron Energization from Magnetic Reconnection in Laser-Driven Plasmas. PHYSICAL REVIEW LETTERS 2016; 116:095003. [PMID: 26991182 DOI: 10.1103/physrevlett.116.095003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Indexed: 06/05/2023]
Abstract
The possibility of studying nonthermal electron energization in laser-driven plasma experiments of magnetic reconnection is studied using two- and three-dimensional particle-in-cell simulations. It is demonstrated that nonthermal electrons with energies more than an order of magnitude larger than the initial thermal energy can be produced in plasma conditions currently accessible in the laboratory. Electrons are accelerated by the reconnection electric field, being injected at varied distances from the X points, and in some cases trapped in plasmoids, before escaping the finite-sized system. Trapped electrons can be further energized by the electric field arising from the motion of the plasmoid. This acceleration gives rise to a nonthermal electron component that resembles a power-law spectrum, containing up to ∼8% of the initial energy of the interacting electrons and ∼24% of the initial magnetic energy. Estimates of the maximum electron energy and of the plasma conditions required to observe suprathermal electron acceleration are provided, paving the way for a new platform for the experimental study of particle acceleration induced by reconnection.
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Affiliation(s)
- Samuel R Totorica
- Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, California 94305, USA
- Department of Physics, Stanford University, Stanford, California 94305, USA
- High Energy Density Science Division, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Tom Abel
- Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, California 94305, USA
- Department of Physics, Stanford University, Stanford, California 94305, USA
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Frederico Fiuza
- High Energy Density Science Division, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
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Baker DN, Dewey RM, Lawrence DJ, Goldsten JO, Peplowski PN, Korth H, Slavin JA, Krimigis SM, Anderson BJ, Ho GC, McNutt RL, Raines JM, Schriver D, Solomon SC. Intense energetic electron flux enhancements in Mercury's magnetosphere: An integrated view with high-resolution observations from MESSENGER. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2016; 121:2171-2184. [PMID: 27830111 PMCID: PMC5076489 DOI: 10.1002/2015ja021778] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 11/20/2015] [Accepted: 12/22/2015] [Indexed: 06/06/2023]
Abstract
The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission to Mercury has provided a wealth of new data about energetic particle phenomena. With observations from MESSENGER's Energetic Particle Spectrometer, as well as data arising from energetic electrons recorded by the X-Ray Spectrometer and Gamma-Ray and Neutron Spectrometer (GRNS) instruments, recent work greatly extends our record of the acceleration, transport, and loss of energetic electrons at Mercury. The combined data sets include measurements from a few keV up to several hundred keV in electron kinetic energy and have permitted relatively good spatial and temporal resolution for many events. We focus here on the detailed nature of energetic electron bursts measured by the GRNS system, and we place these events in the context of solar wind and magnetospheric forcing at Mercury. Our examination of data at high temporal resolution (10 ms) during the period March 2013 through October 2014 supports strongly the view that energetic electrons are accelerated in the near-tail region of Mercury's magnetosphere and are subsequently "injected" onto closed magnetic field lines on the planetary nightside. The electrons populate the plasma sheet and drift rapidly eastward toward the dawn and prenoon sectors, at times executing multiple complete drifts around the planet to form "quasi-trapped" populations.
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Affiliation(s)
- Daniel N Baker
- Laboratory for Atmospheric and Space Physics University of Colorado Boulder Colorado USA
| | - Ryan M Dewey
- Laboratory for Atmospheric and Space Physics University of Colorado Boulder Colorado USA
| | - David J Lawrence
- The Johns Hopkins University Applied Physics Laboratory Laurel Maryland USA
| | - John O Goldsten
- The Johns Hopkins University Applied Physics Laboratory Laurel Maryland USA
| | | | - Haje Korth
- The Johns Hopkins University Applied Physics Laboratory Laurel Maryland USA
| | - James A Slavin
- Department of Atmospheric, Oceanic and Space Sciences University of Michigan Ann Arbor Michigan USA
| | - Stamatios M Krimigis
- The Johns Hopkins University Applied Physics Laboratory Laurel Maryland USA; Office of Space Research and Technology Academy of Athens Athens Greece
| | - Brian J Anderson
- The Johns Hopkins University Applied Physics Laboratory Laurel Maryland USA
| | - George C Ho
- The Johns Hopkins University Applied Physics Laboratory Laurel Maryland USA
| | - Ralph L McNutt
- The Johns Hopkins University Applied Physics Laboratory Laurel Maryland USA
| | - Jim M Raines
- Department of Atmospheric, Oceanic and Space Sciences University of Michigan Ann Arbor Michigan USA
| | - David Schriver
- Department of Physics and Astronomy University of California Los Angeles California USA
| | - Sean C Solomon
- Department of Terrestrial Magnetism Carnegie Institution of Washington Washington District of Columbia USA; Lamont-Doherty Earth Observatory Columbia University Palisades New York USA
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Chen B, Bastian TS, Shen C, Gary DE, Krucker S, Glesener L. Particle acceleration by a solar flare termination shock. Science 2015; 350:1238-42. [PMID: 26785486 DOI: 10.1126/science.aac8467] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Solar flares--the most powerful explosions in the solar system--are also efficient particle accelerators, capable of energizing a large number of charged particles to relativistic speeds. A termination shock is often invoked in the standard model of solar flares as a possible driver for particle acceleration, yet its existence and role have remained controversial. We present observations of a solar flare termination shock and trace its morphology and dynamics using high-cadence radio imaging spectroscopy. We show that a disruption of the shock coincides with an abrupt reduction of the energetic electron population. The observed properties of the shock are well reproduced by simulations. These results strongly suggest that a termination shock is responsible, at least in part, for accelerating energetic electrons in solar flares.
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Affiliation(s)
- Bin Chen
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA.
| | - Timothy S Bastian
- National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA
| | - Chengcai Shen
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
| | - Dale E Gary
- New Jersey Institute of Technology, 323 Martin Luther King Boulevard, Newark, NJ 07102, USA
| | - Säm Krucker
- University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720, USA. University of Applied Sciences and Arts Northwestern Switzerland, Bahnhofstrasse 6, 5210 Windisch, Switzerland
| | - Lindsay Glesener
- University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720, USA. University of Minnesota, Twin Cities, 116 Church Street SE, Minneapolis, MN 55455, USA
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Zank GP, Hunana P, Mostafavi P, Roux JAL, Li G, Webb GM, Khabarova O, Cummings A, Stone E, Decker R. DIFFUSIVE SHOCK ACCELERATION AND RECONNECTION ACCELERATION PROCESSES. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/0004-637x/814/2/137] [Citation(s) in RCA: 124] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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le Roux JA, Webb GM, Zank GP, Khabarova O. Energetic Ion Acceleration by Small-scale Solar Wind Flux Ropes. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/1742-6596/642/1/012015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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