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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: 0] [Impact Index Per Article: 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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Parashar TN, Matthaeus WH. Observations of cross scale energy transfer in the inner heliosphere by Parker Solar Probe. REVIEWS OF MODERN PLASMA PHYSICS 2022; 6:41. [PMCID: PMC9684259 DOI: 10.1007/s41614-022-00097-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 10/02/2022] [Indexed: 11/27/2022]
Abstract
The solar wind, a continuous flow of plasma from the sun, not only shapes the near Earth space environment but also serves as a natural laboratory to study plasma turbulence in conditions that are not achievable in the lab. Starting with the Mariners, for more than five decades, multiple space missions have enabled in-depth studies of solar wind turbulence. Parker Solar Probe (PSP) was launched to explore the origins and evolution of the solar wind. With its state-of-the-art instrumentation and unprecedented close approaches to the sun, PSP is starting a new era of inner heliospheric exploration. In this review we discuss observations of turbulent energy flow across scales in the inner heliosphere as observed by PSP. After providing a quick theoretical overview and a quick recap of turbulence before PSP, we discuss in detail the observations of energy at various scales on its journey from the largest scales to the internal degrees of freedom of the plasma. We conclude with some open ended questions, many of which we hope that PSP will help answer.
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Affiliation(s)
- Tulasi N. Parashar
- grid.267827.e0000 0001 2292 3111School of Chemical and Physical Sciences, Victoria University of Wellington, Gate 7, Kelburn Parade, Kelburn, Wellington, 6012 New Zealand ,grid.33489.350000 0001 0454 4791Department of Physics and Astronomy, University of Delaware, Sharp Laboratory, Newark, Delaware 19711 USA
| | - William H. Matthaeus
- grid.33489.350000 0001 0454 4791Department of Physics and Astronomy, University of Delaware, Sharp Laboratory, Newark, Delaware 19711 USA
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3
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Solar Wind Turbulence from 1 to 45 au. I. Evidence for Dissipation of Magnetic Fluctuations Using Voyager and ACE Observations. ACTA ACUST UNITED AC 2020. [DOI: 10.3847/1538-4357/abab10] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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4
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Sorriso-Valvo L, Catapano F, Retinò A, Le Contel O, Perrone D, Roberts OW, Coburn JT, Panebianco V, Valentini F, Perri S, Greco A, Malara F, Carbone V, Veltri P, Pezzi O, Fraternale F, Di Mare F, Marino R, Giles B, Moore TE, Russell CT, Torbert RB, Burch JL, Khotyaintsev YV. Turbulence-Driven Ion Beams in the Magnetospheric Kelvin-Helmholtz Instability. PHYSICAL REVIEW LETTERS 2019; 122:035102. [PMID: 30735422 DOI: 10.1103/physrevlett.122.035102] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 12/10/2018] [Indexed: 05/20/2023]
Abstract
The description of the local turbulent energy transfer and the high-resolution ion distributions measured by the Magnetospheric Multiscale mission together provide a formidable tool to explore the cross-scale connection between the fluid-scale energy cascade and plasma processes at subion scales. When the small-scale energy transfer is dominated by Alfvénic, correlated velocity, and magnetic field fluctuations, beams of accelerated particles are more likely observed. Here, for the first time, we report observations suggesting the nonlinear wave-particle interaction as one possible mechanism for the energy dissipation in space plasmas.
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Affiliation(s)
- Luca Sorriso-Valvo
- Nanotec/CNR, U.O.S. di Cosenza, Ponte P. Bucci, cubo 31C, 87036 Rende, Italy and Departamento de Física, Escuela Politécnica Nacional, 170517 Quito, Ecuador
| | - Filomena Catapano
- Dipartimento di Fisica, Università della Calabria, Ponte P. Bucci, cubo 31C, 87036 Rende, Italy and LPP-CNRS/Ecole Polytechnique/Sorbonne Université, 91128 Palaiseau Cedex, France
| | - Alessandro Retinò
- LPP-CNRS/Ecole Polytechnique/Sorbonne Université, 91128 Palaiseau Cedex, France
| | - Olivier Le Contel
- LPP-CNRS/Ecole Polytechnique/Sorbonne Université, 91128 Palaiseau Cedex, France
| | - Denise Perrone
- Department of Physics, Imperial College of London, London SW7 2AZ, United Kingdom
| | - Owen W Roberts
- Space Research Institute, Austrian Academy of Sciences, Schmiedlstrasse 6, 8042 Graz, Austria
| | - Jesse T Coburn
- Dipartimento di Fisica, Università della Calabria, Ponte P. Bucci, cubo 31C, 87036 Rende, Italy
| | - Vincenzo Panebianco
- Dipartimento di Fisica, Università della Calabria, Ponte P. Bucci, cubo 31C, 87036 Rende, Italy
| | - Francesco Valentini
- Dipartimento di Fisica, Università della Calabria, Ponte P. Bucci, cubo 31C, 87036 Rende, Italy
| | - Silvia Perri
- Dipartimento di Fisica, Università della Calabria, Ponte P. Bucci, cubo 31C, 87036 Rende, Italy
| | - Antonella Greco
- Dipartimento di Fisica, Università della Calabria, Ponte P. Bucci, cubo 31C, 87036 Rende, Italy
| | - Francesco Malara
- Dipartimento di Fisica, Università della Calabria, Ponte P. Bucci, cubo 31C, 87036 Rende, Italy
| | - Vincenzo Carbone
- Dipartimento di Fisica, Università della Calabria, Ponte P. Bucci, cubo 31C, 87036 Rende, Italy
| | - Pierluigi Veltri
- Dipartimento di Fisica, Università della Calabria, Ponte P. Bucci, cubo 31C, 87036 Rende, Italy
| | - Oreste Pezzi
- Gran Sasso Science Institute, Viale F. Crispi 7, 67100 L'Aquila, Italy and Dipartimento di Fisica, Università della Calabria, Ponte P. Bucci, cubo 31C, 87036 Rende, Italy
| | - Federico Fraternale
- Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, 10129 Torino, Italy
| | - Francesca Di Mare
- Department of Physics, University of Oslo, Sem Sælands Vei 26, Fysikkbygningen 0371 Oslo, Norway
| | - Raffaele Marino
- Laboratoire de Mécanique des Fluides et d'Acoustique, CNRS, École Centrale de Lyon, Université Claude Bernard Lyon 1, INSA de Lyon, F-69134 Écully, France
| | - Barbara Giles
- NASA, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - Thomas E Moore
- NASA, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - Christopher T Russell
- Institute of Geophysics and Planetary Physics, and Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, California 90095-1567, USA
| | - Roy B Torbert
- Space Science Center, University of New Hampshire, Durham, New Hampshire 03824, USA
| | - Jim L Burch
- Southwest Research Institute, San Antonio, Texas 78238-5166, USA
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5
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Comisso L, Sironi L. Particle Acceleration in Relativistic Plasma Turbulence. PHYSICAL REVIEW LETTERS 2018; 121:255101. [PMID: 30608827 DOI: 10.1103/physrevlett.121.255101] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 11/14/2018] [Indexed: 06/09/2023]
Abstract
Due to its ubiquitous presence, turbulence is often invoked to explain the origin of nonthermal particles in astrophysical sources of high-energy emission. With particle-in-cell simulations, we study decaying turbulence in magnetically dominated (or, equivalently, "relativistic") pair plasmas. We find that the generation of a power-law particle energy spectrum is a generic by-product of relativistic turbulence. The power-law slope is harder for higher magnetizations and stronger turbulence levels. In large systems, the slope attains an asymptotic, system-size-independent value, while the high-energy spectral cutoff increases linearly with system size; both the slope and the cutoff do not depend on the dimensionality of our domain. By following a large sample of particles, we show that particle injection happens at reconnecting current sheets; the injected particles are then further accelerated by stochastic interactions with turbulent fluctuations. Our results have important implications for the origin of nonthermal particles in high-energy astrophysical sources.
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Affiliation(s)
- Luca Comisso
- Department of Astronomy and Columbia Astrophysics Laboratory, Columbia University, New York, New York 10027, USA
| | - Lorenzo Sironi
- Department of Astronomy and Columbia Astrophysics Laboratory, Columbia University, New York, New York 10027, USA
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Palmroth M, Ganse U, Pfau-Kempf Y, Battarbee M, Turc L, Brito T, Grandin M, Hoilijoki S, Sandroos A, von Alfthan S. Vlasov methods in space physics and astrophysics. ACTA ACUST UNITED AC 2018; 4:1. [PMID: 30680308 PMCID: PMC6319499 DOI: 10.1007/s41115-018-0003-2] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 07/06/2018] [Indexed: 11/26/2022]
Abstract
This paper reviews Vlasov-based numerical methods used to model plasma in space physics and astrophysics. Plasma consists of collectively behaving charged particles that form the major part of baryonic matter in the Universe. Many concepts ranging from our own planetary environment to the Solar system and beyond can be understood in terms of kinetic plasma physics, represented by the Vlasov equation. We introduce the physical basis for the Vlasov system, and then outline the associated numerical methods that are typically used. A particular application of the Vlasov system is Vlasiator, the world’s first global hybrid-Vlasov simulation for the Earth’s magnetic domain, the magnetosphere. We introduce the design strategies for Vlasiator and outline its numerical concepts ranging from solvers to coupling schemes. We review Vlasiator’s parallelisation methods and introduce the used high-performance computing (HPC) techniques. A short review of verification, validation and physical results is included. The purpose of the paper is to present the Vlasov system and introduce an example implementation, and to illustrate that even with massive computational challenges, an accurate description of physics can be rewarding in itself and significantly advance our understanding. Upcoming supercomputing resources are making similar efforts feasible in other fields as well, making our design options relevant for others facing similar challenges.
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Affiliation(s)
- Minna Palmroth
- Department of Physics, University of Helsinki, Helsinki, Finland
- Finnish Meteorological Institute, Helsinki, Finland
| | - Urs Ganse
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Yann Pfau-Kempf
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Markus Battarbee
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Lucile Turc
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Thiago Brito
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Maxime Grandin
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Sanni Hoilijoki
- Laboratory for Atmospheric and Space Plasma Physics, University of Colorado at Boulder, Boulder, CO USA
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7
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Malara F, Pezzi O, Valentini F. Exact hybrid Vlasov equilibria for sheared plasmas with in-plane and out-of-plane magnetic field. Phys Rev E 2018; 97:053212. [PMID: 29906964 DOI: 10.1103/physreve.97.053212] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Indexed: 11/07/2022]
Abstract
The hybrid Vlasov-Maxwell system of equations is suitable to describe a magnetized plasma at scales on the order of or larger than proton kinetic scales. An exact stationary solution is presented by revisiting previous results with a uniform-density shear flow, directed either parallel or perpendicular to a uniform magnetic field, and by adapting the solution to the hybrid Vlasov-Maxwell model. A quantitative characterization of the equilibrium distribution function is provided by studying both analytically and numerically the temperature anisotropy and gyrotropy and the heat flux. In both cases, in the shear region, the velocity distribution significantly departs from local thermodynamical equilibrium. A comparison between the time behavior of the usual "fluidlike" equilibrium shifted Maxwellian and the exact stationary solutions is carried out by means of numerical simulations of the hybrid Vlasov-Maxwell equations. These hybrid equilibria can be employed as unperturbed states for numerous problems which involve sheared flows, such as the wave propagation in an inhomogeneous background and the onset of the Kelvin-Helmholtz instability.
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Affiliation(s)
- F Malara
- Dipartimento di Fisica, Università della Calabria, 87036, Rende (Cosenza), Italy
| | - O Pezzi
- Dipartimento di Fisica, Università della Calabria, 87036, Rende (Cosenza), Italy
| | - F Valentini
- Dipartimento di Fisica, Università della Calabria, 87036, Rende (Cosenza), Italy
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8
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Arbitrary-order Hilbert Spectral Analysis and Intermittency in Solar Wind Density Fluctuations. ACTA ACUST UNITED AC 2018. [DOI: 10.3847/1538-4357/aabcc2] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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9
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10
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Camporeale E, Sorriso-Valvo L, Califano F, Retinò A. Coherent Structures and Spectral Energy Transfer in Turbulent Plasma: A Space-Filter Approach. PHYSICAL REVIEW LETTERS 2018; 120:125101. [PMID: 29694094 DOI: 10.1103/physrevlett.120.125101] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 02/15/2018] [Indexed: 06/08/2023]
Abstract
Plasma turbulence at scales of the order of the ion inertial length is mediated by several mechanisms, including linear wave damping, magnetic reconnection, the formation and dissipation of thin current sheets, and stochastic heating. It is now understood that the presence of localized coherent structures enhances the dissipation channels and the kinetic features of the plasma. However, no formal way of quantifying the relationship between scale-to-scale energy transfer and the presence of spatial structures has been presented so far. In the Letter we quantify such a relationship analyzing the results of a two-dimensional high-resolution Hall magnetohydrodynamic simulation. In particular, we employ the technique of space filtering to derive a spectral energy flux term which defines, in any point of the computational domain, the signed flux of spectral energy across a given wave number. The characterization of coherent structures is performed by means of a traditional two-dimensional wavelet transformation. By studying the correlation between the spectral energy flux and the wavelet amplitude, we demonstrate the strong relationship between scale-to-scale transfer and coherent structures. Furthermore, by conditioning one quantity with respect to the other, we are able for the first time to quantify the inhomogeneity of the turbulence cascade induced by topological structures in the magnetic field. Taking into account the low space-filling factor of coherent structures (i.e., they cover a small portion of space), it emerges that 80% of the spectral energy transfer (both in the direct and inverse cascade directions) is localized in about 50% of space, and 50% of the energy transfer is localized in only 25% of space.
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Affiliation(s)
- E Camporeale
- Center for Mathematics and Computer Science (CWI), Amsterdam 1098 XG, The Netherlands
| | - L Sorriso-Valvo
- CNR-Nanotec-Unità di Cosenza, Ponte P. Bucci, cubo 31C, 87036 Rende, Italy
| | - F Califano
- Dipartimento di Fisica "E. Fermi," Università di Pisa, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
| | - A Retinò
- Centre National de la Recherche Scientifique, LPP UMR 7648, Ecole Polytechnique, Universit Pierre et Marie Curie Paris VI, Observatoire de Paris, Route de Saclay Palaiseau 91128, France
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11
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In Situ Observation of Intermittent Dissipation at Kinetic Scales in the Earth's Magnetosheath. ACTA ACUST UNITED AC 2018. [DOI: 10.3847/2041-8213/aaadf8] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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12
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13
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Servidio S, Chasapis A, Matthaeus WH, Perrone D, Valentini F, Parashar TN, Veltri P, Gershman D, Russell CT, Giles B, Fuselier SA, Phan TD, Burch J. Magnetospheric Multiscale Observation of Plasma Velocity-Space Cascade: Hermite Representation and Theory. PHYSICAL REVIEW LETTERS 2017; 119:205101. [PMID: 29219385 DOI: 10.1103/physrevlett.119.205101] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Indexed: 06/07/2023]
Abstract
Plasma turbulence is investigated using unprecedented high-resolution ion velocity distribution measurements by the Magnetospheric Multiscale mission (MMS) in the Earth's magnetosheath. This novel observation of a highly structured particle distribution suggests a cascadelike process in velocity space. Complex velocity space structure is investigated using a three-dimensional Hermite transform, revealing, for the first time in observational data, a power-law distribution of moments. In analogy to hydrodynamics, a Kolmogorov approach leads directly to a range of predictions for this phase-space transport. The scaling theory is found to be in agreement with observations. The combined use of state-of-the-art MMS data sets, novel implementation of a Hermite transform method, and scaling theory of the velocity cascade opens new pathways to the understanding of plasma turbulence and the crucial velocity space features that lead to dissipation in plasmas.
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Affiliation(s)
- S Servidio
- Dipartimento di Fisica, Università della Calabria, I-87036 Cosenza, Italy
| | - A Chasapis
- Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | - W H Matthaeus
- Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | - D Perrone
- European Space Agency, ESAC, 28692 Madrid, Spain
| | - F Valentini
- Dipartimento di Fisica, Università della Calabria, I-87036 Cosenza, Italy
| | - T N Parashar
- Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | - P Veltri
- Dipartimento di Fisica, Università della Calabria, I-87036 Cosenza, Italy
| | - D Gershman
- NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - C T Russell
- University of California at Los Angeles, Los Angeles, California 90095, USA
| | - B Giles
- NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - S A Fuselier
- Southwest Research Institute, San Antonio, Texas 78238, USA
- University of Texas at San Antonio, San Antonio, Texas 78249, USA
| | - T D Phan
- University of California, Berkeley, California 94720, USA
| | - J Burch
- Southwest Research Institute, San Antonio, Texas 78238, USA
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14
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Pezzi O, Malara F, Servidio S, Valentini F, Parashar TN, Matthaeus WH, Veltri P. Turbulence generation during the head-on collision of Alfvénic wave packets. Phys Rev E 2017; 96:023201. [PMID: 28950603 DOI: 10.1103/physreve.96.023201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Indexed: 06/07/2023]
Abstract
The description of the Moffatt and Parker problem recently revisited by O. Pezzi et al. [Astrophys. J. 834, 166 (2017)1538-435710.3847/1538-4357/834/2/166] is here extended by analyzing the features of the turbulence produced by the interaction of two colliding Alfvénic wave packets in a kinetic plasma. Although the approach based on the presence of linear modes features is still helpful in characterizing some low-energy fluctuations, other signatures, which go beyond the pure linear modes analysis, are recovered, such as the significant weakening of clear dispersion relations and the production of zero frequency fluctuations.
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Affiliation(s)
- O Pezzi
- Dipartimento di Fisica, Università della Calabria, 87036 Rende (CS), Italy
| | - F Malara
- Dipartimento di Fisica, Università della Calabria, 87036 Rende (CS), Italy
| | - S Servidio
- Dipartimento di Fisica, Università della Calabria, 87036 Rende (CS), Italy
| | - F Valentini
- Dipartimento di Fisica, Università della Calabria, 87036 Rende (CS), Italy
| | - T N Parashar
- Department of Physics and Astronomy, University of Delaware, Newark Delaware 19716, USA
| | - W H Matthaeus
- Department of Physics and Astronomy, University of Delaware, Newark Delaware 19716, USA
| | - P Veltri
- Dipartimento di Fisica, Università della Calabria, 87036 Rende (CS), Italy
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15
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Yang Y, Matthaeus WH, Parashar TN, Wu P, Wan M, Shi Y, Chen S, Roytershteyn V, Daughton W. Energy transfer channels and turbulence cascade in Vlasov-Maxwell turbulence. Phys Rev E 2017; 95:061201. [PMID: 28709288 DOI: 10.1103/physreve.95.061201] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Indexed: 06/07/2023]
Abstract
Analysis of the Vlasov-Maxwell equations from the perspective of turbulence cascade clarifies the role of electromagnetic work, and reveals the importance of the pressure-strain relation in generating internal energy. Particle-in-cell simulation demonstrates the relative importance of the several energy exchange terms, indicating that the traceless pressure-strain interaction "Pi-D" is of particular importance for both electrons and protons. The Pi-D interaction and the second tensor invariants of the strain are highly localized in similar spatial regions, indicating that energy transfer occurs preferentially in coherent structures. The collisionless turbulence cascade may be fruitfully explored by study of these energy transfer channels, in addition to examining transfer across spatial scales.
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Affiliation(s)
- Yan Yang
- State Key Laboratory for Turbulence and Complex Systems, Center for Applied Physics and Technology, College of Engineering, Peking University, Beijing 100871, China
- Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | - W H Matthaeus
- Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | - T N Parashar
- Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | - P Wu
- Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
- School of Mathematics and Physics, Queen's University Belfast, BT7 1NN, United Kingdom
| | - M Wan
- Department of Mechanics and Aerospace Engineering, South University of Science and Technology of China, Shenzhen, Guangdong 518055, China
| | - Y Shi
- State Key Laboratory for Turbulence and Complex Systems, Center for Applied Physics and Technology, College of Engineering, Peking University, Beijing 100871, China
| | - S Chen
- State Key Laboratory for Turbulence and Complex Systems, Center for Applied Physics and Technology, College of Engineering, Peking University, Beijing 100871, China
- Department of Mechanics and Aerospace Engineering, South University of Science and Technology of China, Shenzhen, Guangdong 518055, China
| | | | - W Daughton
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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16
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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: 2] [Impact Index Per Article: 0.3] [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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17
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Servidio S, Haynes CT, Matthaeus WH, Burgess D, Carbone V, Veltri P. Explosive Particle Dispersion in Plasma Turbulence. PHYSICAL REVIEW LETTERS 2016; 117:095101. [PMID: 27610862 DOI: 10.1103/physrevlett.117.095101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Indexed: 06/06/2023]
Abstract
Particle dynamics are investigated in plasma turbulence, using self-consistent kinetic simulations, in two dimensions. In the steady state, the trajectories of single protons and proton pairs are studied, at different values of plasma β (ratio between kinetic and magnetic pressure). For single-particle displacements, results are consistent with fluids and magnetic field line dynamics, where particles undergo normal diffusion for very long times, with higher β's being more diffusive. In an intermediate time range, with separations lying in the inertial range, particles experience an explosive dispersion in time, consistent with the Richardson prediction. These results, obtained for the first time with a self-consistent kinetic model, are relevant for astrophysical and laboratory plasmas, where turbulence is crucial for heating, mixing, and acceleration processes.
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Affiliation(s)
- S Servidio
- Dipartimento di Fisica, Università della Calabria, I-87036 Cosenza, Italy
| | - C T Haynes
- School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
| | - W H Matthaeus
- Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | - D Burgess
- School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
| | - V Carbone
- Dipartimento di Fisica, Università della Calabria, I-87036 Cosenza, Italy
| | - P Veltri
- Dipartimento di Fisica, Università della Calabria, I-87036 Cosenza, Italy
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18
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Del Sarto D, Pegoraro F, Califano F. Pressure anisotropy and small spatial scales induced by velocity shear. Phys Rev E 2016; 93:053203. [PMID: 27300991 DOI: 10.1103/physreve.93.053203] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Indexed: 06/06/2023]
Abstract
By including the full pressure tensor dynamics in a fluid plasma model, we show that a sheared velocity field can provide an effective mechanism that makes the initial isotropic pressure nongyrotropic. This is distinct from the usual gyrotropic anisotropy related to the fluid compressibility and usually accounted for in double-adiabatic models. We determine the time evolution of the pressure agyrotropy and discuss how the propagation of "magnetoelastic perturbations" can affect the pressure tensor anisotropization and its spatial filamentation, which are due to the action of both the magnetic field and the flow strain tensor. We support this analysis with a numerical integration of the nonlinear equations describing the pressure tensor evolution.
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Affiliation(s)
- D Del Sarto
- Institut Jean Lamour, UMR CNRS 7198 and Université de Lorraine, B.P. 70239, F-54506 Vandœuvre-lès-Nancy Cedex, France
| | - F Pegoraro
- Physics Department and CNISM, University of Pisa, 56216 Pisa, Italy
| | - F Califano
- Physics Department and CNISM, University of Pisa, 56216 Pisa, Italy
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19
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Pezzi O, Valentini F, Veltri P. Collisional Relaxation of Fine Velocity Structures in Plasmas. PHYSICAL REVIEW LETTERS 2016; 116:145001. [PMID: 27104713 DOI: 10.1103/physrevlett.116.145001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Indexed: 06/05/2023]
Abstract
The existence of several characteristic times during the collisional relaxation of fine velocity structures is investigated by means of Eulerian numerical simulations of a spatially homogeneous force-free weakly collisional plasma. The effect of smoothing out velocity gradients on the evolution of global quantities, such as temperature and entropy, is discussed, suggesting that plasma collisionality can locally increase due to velocity space deformations of the particle velocity distribution function. These results support the idea that high-resolution measurements of the particle velocity distribution function are crucial for an accurate description of weakly collisional systems, such as the solar wind, in order to answer relevant scientific questions, related, for example, to particle heating and energization.
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Affiliation(s)
- Oreste Pezzi
- Dipartimento di Fisica, Università della Calabria, 87036 Rende (CS), Italy
| | | | - Pierluigi Veltri
- Dipartimento di Fisica, Università della Calabria, 87036 Rende (CS), Italy
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20
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Chandran BDG, Schekochihin AA, Mallet A. INTERMITTENCY AND ALIGNMENT IN STRONG RMHD TURBULENCE. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/0004-637x/807/1/39] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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21
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Matthaeus WH, Wan M, Servidio S, Greco A, Osman KT, Oughton S, Dmitruk P. Intermittency, nonlinear dynamics and dissipation in the solar wind and astrophysical plasmas. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2015; 373:20140154. [PMID: 25848085 PMCID: PMC4394684 DOI: 10.1098/rsta.2014.0154] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/12/2015] [Indexed: 05/29/2023]
Abstract
An overview is given of important properties of spatial and temporal intermittency, including evidence of its appearance in fluids, magnetofluids and plasmas, and its implications for understanding of heliospheric plasmas. Spatial intermittency is generally associated with formation of sharp gradients and coherent structures. The basic physics of structure generation is ideal, but when dissipation is present it is usually concentrated in regions of strong gradients. This essential feature of spatial intermittency in fluids has been shown recently to carry over to the realm of kinetic plasma, where the dissipation function is not known from first principles. Spatial structures produced in intermittent plasma influence dissipation, heating, and transport and acceleration of charged particles. Temporal intermittency can give rise to very long time correlations or a delayed approach to steady-state conditions, and has been associated with inverse cascade or quasi-inverse cascade systems, with possible implications for heliospheric prediction.
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Affiliation(s)
- W H Matthaeus
- Department of Physics and Astronomy, University of Delaware, Newark, DE 19716, USA Dipartimento di Fisica, Università della Calabria, Arcavacata, Rende, Italy Dipartimento di Fisica e Astronomia, Università di Firenze, Firenze, Italy
| | - Minping Wan
- Department of Physics and Astronomy, University of Delaware, Newark, DE 19716, USA
| | - S Servidio
- Dipartimento di Fisica, Università della Calabria, Arcavacata, Rende, Italy
| | - A Greco
- Dipartimento di Fisica, Università della Calabria, Arcavacata, Rende, Italy
| | - K T Osman
- Centre for Fusion, Space and Astrophysics, University of Warwick, Coventry CV4 7AL, UK
| | - S Oughton
- Department of Mathematics, University of Waikato, Hamilton, New Zealand
| | - P Dmitruk
- Departamento de Fisica, FCEN, Universidad de Buenos Aires, Buenos Aires, Argentina
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22
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Wan M, Matthaeus WH, Roytershteyn V, Karimabadi H, Parashar T, Wu P, Shay M. Intermittent Dissipation and Heating in 3D Kinetic Plasma Turbulence. PHYSICAL REVIEW LETTERS 2015; 114:175002. [PMID: 25978241 DOI: 10.1103/physrevlett.114.175002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Indexed: 06/04/2023]
Abstract
High resolution, fully kinetic, three dimensional (3D) simulation of collisionless plasma turbulence shows the development of turbulence characterized by sheetlike current density structures spanning a range of scales. The nonlinear evolution is initialized with a long wavelength isotropic spectrum of fluctuations having polarizations transverse to an imposed mean magnetic field. We present evidence that these current sheet structures are sites for heating and dissipation, and that stronger currents signify higher dissipation rates. The analyses focus on quantities such as J·E, electron, and proton temperatures, and conditional averages of these quantities based on local electric current density. Evidently, kinetic scale plasma, like magnetohydrodynamics, becomes intermittent due to current sheet formation, leading to the expectation that heating and dissipation in astrophysical and space plasmas may be highly nonuniform. Comparison with previous results from 2D kinetic simulations, as well as high frequency solar wind observational data, are discussed.
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Affiliation(s)
- M Wan
- Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | - W H Matthaeus
- Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | | | | | - T Parashar
- Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | - P Wu
- Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | - M Shay
- Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
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23
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Osman KT, Matthaeus WH, Kiyani KH, Hnat B, Chapman SC. Proton kinetic effects and turbulent energy cascade rate in the solar wind. PHYSICAL REVIEW LETTERS 2013; 111:201101. [PMID: 24289672 DOI: 10.1103/physrevlett.111.201101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2013] [Indexed: 06/02/2023]
Abstract
The first observed connection between kinetic instabilities driven by proton temperature anisotropy and estimated energy cascade rates in the turbulent solar wind is reported using measurements from the Wind spacecraft at 1 AU. We find enhanced cascade rates are concentrated along the boundaries of the (β∥, T⊥/T∥) plane, which includes regions theoretically unstable to the mirror and firehose instabilities. A strong correlation is observed between the estimated cascade rate and kinetic effects such as temperature anisotropy and plasma heating, resulting in protons 5-6 times hotter and 70%-90% more anisotropic than under typical isotropic plasma conditions. These results offer new insights into kinetic processes in a turbulent regime.
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Affiliation(s)
- K T Osman
- Centre for Fusion, Space, and Astrophysics, University of Warwick, Coventry CV4 7AL, United Kingdom
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24
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Wu P, Wan M, Matthaeus WH, Shay MA, Swisdak M. Von Kármán energy decay and heating of protons and electrons in a kinetic turbulent plasma. PHYSICAL REVIEW LETTERS 2013; 111:121105. [PMID: 24093244 DOI: 10.1103/physrevlett.111.121105] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Indexed: 06/02/2023]
Abstract
Decay in time of undriven weakly collisional kinetic plasma turbulence in systems large compared to the ion kinetic scales is investigated using fully electromagnetic particle-in-cell simulations initiated with transverse flow and magnetic disturbances, constant density, and a strong guide field. The observed energy decay is consistent with the von Kármán hypothesis of similarity decay, in a formulation adapted to magnetohydrodyamics. Kinetic dissipation occurs at small scales, but the overall rate is apparently controlled by large scale dynamics. At small turbulence amplitudes the electrons are preferentially heated. At larger amplitudes proton heating is the dominant effect. In the solar wind and corona the protons are typically hotter, suggesting that these natural systems are in the large amplitude turbulence regime.
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Affiliation(s)
- P Wu
- Department of Physics and Astronomy, Bartol Research Institute, University of Delaware, Newark, Delaware 19716, USA
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25
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Greco A, Valentini F, Servidio S, Matthaeus WH. Inhomogeneous kinetic effects related to intermittent magnetic discontinuities. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 86:066405. [PMID: 23368057 DOI: 10.1103/physreve.86.066405] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 11/13/2012] [Indexed: 06/01/2023]
Abstract
A connection between kinetic processes and two-dimensional intermittent plasma turbulence is observed using direct numerical simulations of a hybrid Vlasov-Maxwell model, in which the Vlasov equation is solved for protons, while the electrons are described as a massless fluid. During the development of turbulence, the proton distribution functions depart from the typical configuration of local thermodynamic equilibrium, displaying statistically significant non-Maxwellian features. In particular, temperature anisotropy and distortions are concentrated near coherent structures, generated as the result of the turbulent cascade, such as current sheets, which are nonuniformly distributed in space. Here, the partial variance of increments (PVI) method has been employed to identify high magnetic stress regions within a two-dimensional turbulent pattern. A quantitative association between non-Maxwellian features and coherent structures is established.
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Affiliation(s)
- A Greco
- Dipartimento di Fisica, Università della Calabria, I-87036 Cosenza, Italy
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26
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Osman KT, Matthaeus WH, Hnat B, Chapman SC. Kinetic signatures and intermittent turbulence in the solar wind plasma. PHYSICAL REVIEW LETTERS 2012; 108:261103. [PMID: 23004954 DOI: 10.1103/physrevlett.108.261103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Indexed: 06/01/2023]
Abstract
A connection between kinetic processes and intermittent turbulence is observed in the solar wind plasma using measurements from the Wind spacecraft at 1 A.U. In particular, kinetic effects such as temperature anisotropy and plasma heating are concentrated near coherent structures, such as current sheets, which are nonuniformly distributed in space. Furthermore, these coherent structures are preferentially found in plasma unstable to the mirror and firehose instabilities. The inhomogeneous heating in these regions, which is present in both the magnetic field parallel and perpendicular temperature components, results in protons at least 3-4 times hotter than under typical stable plasma conditions. These results offer a new understanding of kinetic processes in a turbulent regime, where linear Vlasov theory is not sufficient to explain the inhomogeneous plasma dynamics operating near non-Gaussian structures.
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Affiliation(s)
- K T Osman
- Centre for Fusion, Space and Astrophysics, University of Warwick, Coventry, CV4 7AL, United Kingdom.
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