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Cassak PA, Barbhuiya MH, Liang H, Argall MR. Quantifying Energy Conversion in Higher-Order Phase Space Density Moments in Plasmas. PHYSICAL REVIEW LETTERS 2023; 130:085201. [PMID: 36898122 DOI: 10.1103/physrevlett.130.085201] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 01/09/2023] [Accepted: 01/24/2023] [Indexed: 06/18/2023]
Abstract
Weakly collisional and collisionless plasmas are typically far from local thermodynamic equilibrium (LTE), and understanding energy conversion in such systems is a forefront research problem. The standard approach is to investigate changes in internal (thermal) energy and density, but this omits energy conversion that changes any higher-order moments of the phase space density. In this Letter, we calculate from first principles the energy conversion associated with all higher moments of the phase space density for systems not in LTE. Particle-in-cell simulations of collisionless magnetic reconnection reveal that energy conversion associated with higher-order moments can be locally significant. The results may be useful in numerous plasma settings, such as reconnection, turbulence, shocks, and wave-particle interactions in heliospheric, planetary, and astrophysical plasmas.
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Affiliation(s)
- Paul A Cassak
- 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
| | - Haoming Liang
- Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, Huntsville, Alabama 35899, USA
| | - Matthew R Argall
- Space Science Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, New Hampshire 03824, USA
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2
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Jara-Almonte J, Ji H. Thermodynamic Phase Transition in Magnetic Reconnection. PHYSICAL REVIEW LETTERS 2021; 127:055102. [PMID: 34397253 DOI: 10.1103/physrevlett.127.055102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/30/2021] [Accepted: 06/17/2021] [Indexed: 06/13/2023]
Abstract
By examining the entropy production in fully kinetic simulations of collisional plasmas, it is shown that the transition from collisional Sweet-Parker reconnection to collisionless Hall reconnection may be viewed as a thermodynamic phase transition. The phase transition occurs when the reconnection electric field satisfies E=E_{D}sqrt[m_{e}/m_{i}], where m_{e}/m_{i} is the electron-to-ion mass ratio and E_{D} is the Dreicer electric field. This condition applies for all m_{i}/m_{e}, including m_{i}/m_{e}=1, where the Hall regime vanishes and a direct phase transition from the collisional to the kinetic regime occurs. In the limit m_{e}/m_{i}→0, this condition is equivalent to there being a critical electron temperature T_{e}≈m_{i}Ω_{i}^{2}δ^{2}, where Ω_{i} is the ion cyclotron frequency and δ is the current sheet half-thickness. The heat capacity of the current sheet changes discontinuously across the phase transition, and a critical power law is identified in an effective heat capacity. A model for the time-dependent evolution of an isolated current sheet in the collisional regime is derived.
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Affiliation(s)
- J Jara-Almonte
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - H Ji
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
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Egedal J, Ng J, Le A, Daughton W, Wetherton B, Dorelli J, Gershman D, Rager A. Pressure Tensor Elements Breaking the Frozen-In Law During Reconnection in Earth's Magnetotail. PHYSICAL REVIEW LETTERS 2019; 123:225101. [PMID: 31868399 DOI: 10.1103/physrevlett.123.225101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 08/22/2019] [Indexed: 06/10/2023]
Abstract
Aided by fully kinetic simulations, spacecraft observations of magnetic reconnection in Earth's magnetotail are analyzed. The structure of the electron diffusion region is in quantitative agreement with the numerical model. Of special interest, the spacecraft data reveal how reconnection is mediated by off-diagonal stress in the electron pressure tensor breaking the frozen-in law of the electron fluid.
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Affiliation(s)
- J Egedal
- Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - J Ng
- Center for Heliophysics, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - A Le
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - W Daughton
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - B Wetherton
- Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - J Dorelli
- Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - D Gershman
- Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - A Rager
- Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
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Nakamura R, Genestreti KJ, Nakamura T, Baumjohann W, Varsani A, Nagai T, Bessho N, Burch JL, Denton RE, Eastwood JP, Ergun RE, Gershman DJ, Giles BL, Hasegawa H, Hesse M, Lindqvist P, Russell CT, Stawarz JE, Strangeway RJ, Torbert RB. Structure of the Current Sheet in the 11 July 2017 Electron Diffusion Region Event. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2019; 124:1173-1186. [PMID: 31008008 PMCID: PMC6472497 DOI: 10.1029/2018ja026028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 12/16/2018] [Accepted: 12/19/2018] [Indexed: 06/09/2023]
Abstract
The structure of the current sheet along the Magnetospheric Multiscale (MMS) orbit is examined during the 11 July 2017 Electron Diffusion Region (EDR) event. The location of MMS relative to the X-line is deduced and used to obtain the spatial changes in the electron parameters. The electron velocity gradient values are used to estimate the reconnection electric field sustained by nongyrotropic pressure. It is shown that the observations are consistent with theoretical expectations for an inner EDR in 2-D reconnection. That is, the magnetic field gradient scale, where the electric field due to electron nongyrotropic pressure dominates, is comparable to the gyroscale of the thermal electrons at the edge of the inner EDR. Our approximation of the MMS observations using a steady state, quasi-2-D, tailward retreating X-line was valid only for about 1.4 s. This suggests that the inner EDR is localized; that is, electron outflow jet braking takes place within an ion inertia scale from the X-line. The existence of multiple events or current sheet processes outside the EDR may play an important role in the geometry of reconnection in the near-Earth magnetotail.
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Affiliation(s)
- Rumi Nakamura
- Space Research InstituteAustrian Academy of SciencesGrazAustria
| | - Kevin J. Genestreti
- Space Research InstituteAustrian Academy of SciencesGrazAustria
- Space Science CenterUniversity New HampshireDurhamNHUSA
| | - Takuma Nakamura
- Space Research InstituteAustrian Academy of SciencesGrazAustria
| | | | - Ali Varsani
- Mullard Space Science LaboratoryUniversity College LondonDorkingUK
| | - Tsugunobu Nagai
- Institute of Space and Astronautical ScienceJapan Aerospace Exploration AgencySagamiharaJapan
| | | | | | | | | | - Robert E. Ergun
- Department of Astrophysical and Planetary SciencesUniversity of Colorado BoulderBoulderCOUSA
| | | | | | - Hiroshi Hasegawa
- Institute of Space and Astronautical ScienceJapan Aerospace Exploration AgencySagamiharaJapan
| | - Michael Hesse
- Department of Physics and TechnologyUniversity of BergenBergenNorway
| | | | - Christopher T. Russell
- Department of Earth, Planetary, and Space SciencesUniversity of California, Los AngelesLos AngelesCAUSA
| | | | - Robert J. Strangeway
- Department of Earth, Planetary, and Space SciencesUniversity of California, Los AngelesLos AngelesCAUSA
| | - Roy B. Torbert
- Space Science CenterUniversity New HampshireDurhamNHUSA
- Southwest Research InstituteSan AntonioTXUSA
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Che H, Schiff C, Le G, Dorelli J, Giles B, Moore T. Quantifying the Effect of Non-Larmor Motion of Electrons on the Pressure Tensor. PHYSICS OF PLASMAS 2018; 25:032101. [PMID: 32905417 PMCID: PMC7473318 DOI: 10.1063/1.5016853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In space plasma, various effects of magnetic reconnection and turbulence cause the electron motion to significantly deviate from their Larmor orbits. Collectively these orbits affect the electron velocity distribution function and lead to the appearance of the "non-gyrotropic" elements in the pressure tensor. Quantification of this effect has important applications in space and laboratory plasma, one of which is tracing the electron diffusion region (EDR) of magnetic reconnection in space observations. Three different measures of agyrotropy of pressure tensor have previously been proposed, namely, A∅ e , Dng and Q. The multitude of contradictory measures has caused confusion within the community. We revisit the problem by considering the basic properties an agyrotropy measure should have. We show that A∅ e , Dng and Q are all defined based on the sum of the principle minors (i.e. the rotation invariant I 2) of the pressure tensor. We discuss in detail the problems of I 2-based measures and explain why they may produce ambiguous and biased results. We introduce a new measure AG constructed based on the determinant of the pressure tensor (i.e. the rotation invariant I 3) which does not suffer from the problems of I 2-based measures. We compare AG with other measures in 2 and 3-dimension particle-in-cell magnetic reconnection simulations, and show that AG can effectively trace the EDR of reconnection in both Harris and force-free current sheets. On the other hand, A∅ e does not show prominent peaks in the EDR and part of the separatrix in the force-free reconnection simulations, demonstrating that A∅ e does not measure all the non-gyrotropic effects in this case, and is not suitable for studying magnetic reconnection in more general situations other than Harris sheet reconnection.
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Affiliation(s)
- H Che
- University of Maryland, College Park, MD, 20742, USA
- NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA
| | - C Schiff
- NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA
| | - G Le
- NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA
| | - J Dorelli
- NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA
| | - B Giles
- NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA
| | - T Moore
- NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA
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Pritchett PL. Three-dimensional collisionless magnetic reconnection in the presence of a guide field. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2003ja009999] [Citation(s) in RCA: 241] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Pritchett PL. Geospace Environment Modeling magnetic reconnection challenge: Simulations with a full particle electromagnetic code. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/1999ja001006] [Citation(s) in RCA: 300] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Ma ZW, Bhattacharjee A. Hall magnetohydrodynamic reconnection: The Geospace Environment Modeling challenge. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/1999ja001004] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Kuznetsova MM, Hesse M, Winske D. Collisionless reconnection supported by nongyrotropic pressure effects in hybrid and particle simulations. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/1999ja001003] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Shay MA, Drake JF, Rogers BN, Denton RE. Alfvénic collisionless magnetic reconnection and the Hall term. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/1999ja001007] [Citation(s) in RCA: 369] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Hesse M, Birn J, Kuznetsova M. Collisionless magnetic reconnection: Electron processes and transport modeling. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/1999ja001002] [Citation(s) in RCA: 164] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Birn J, Drake JF, Shay MA, Rogers BN, Denton RE, Hesse M, Kuznetsova M, Ma ZW, Bhattacharjee A, Otto A, Pritchett PL. Geospace Environmental Modeling (GEM) Magnetic Reconnection Challenge. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/1999ja900449] [Citation(s) in RCA: 991] [Impact Index Per Article: 43.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Sitnov MI, Zelenyi LM, Malova HV, Sharma AS. Thin current sheet embedded within a thicker plasma sheet: Self-consistent kinetic theory. ACTA ACUST UNITED AC 2000. [DOI: 10.1029/1999ja000431] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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14
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Bhattacharjee A, Ma ZW, Wang X. Impulsive reconnection dynamics in collisionless laboratory and space plasmas. ACTA ACUST UNITED AC 1999. [DOI: 10.1029/1998ja900094] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Hesse M, Winske D. Electron dissipation in collisionless magnetic reconnection. ACTA ACUST UNITED AC 1998. [DOI: 10.1029/98ja01570] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Shay MA, Drake JF, Denton RE, Biskamp D. Structure of the dissipation region during collisionless magnetic reconnection. ACTA ACUST UNITED AC 1998. [DOI: 10.1029/97ja03528] [Citation(s) in RCA: 303] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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