Article
Geosciences, Multidisciplinary
Z. H. Zhong, M. Zhou, D. B. Graham, Yu. V. Khotyaintsev, Y. F. Wu, O. Le Contel, H. M. Li, X. Tao, R. X. Tang, X. H. Deng
Summary: This paper investigates the whistler-mode waves within an electron-scale current sheet and measures their dispersion relation for the first time. The study shows that the drifting electron component along the magnetic field critically modifies the dispersion relation and demonstrates that these whistler waves propagate into the diffusion region from outside rather than being locally excited.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Physics, Fluids & Plasmas
C. Granier, D. Borgogno, L. Comisso, D. Grasso, E. Tassi, R. Numata
Summary: The marginal stability conditions for the formation of plasmoids in a purely collisionless and strong guide field situation are investigated in this study. It is found that plasmoids can be obtained from current sheets with a smaller aspect ratio in the marginal stability current layers.
Review
Physics, Multidisciplinary
Quanming Lu, Huishan Fu, Rongsheng Wang, San Lu
Summary: Magnetic reconnection is the physical mechanism for explosive phenomena in the solar atmosphere and planetary magnetospheres, where plasma is usually collisionless. In the standard model of collisionless magnetic reconnection, the diffusion region consists of two substructures: an electron diffusion region embedded in an ion diffusion region. Observations from spacecraft and kinetic simulations have provided opportunities to study collisionless magnetic reconnection beyond the standard model.
Article
Nanoscience & Nanotechnology
Aohua Mao, Zhibin Wang
Summary: Plasmas with low-temperature ions are commonly observed in solar-terrestrial space and fusion plasmas. This study focuses on the effects of multiple ion temperatures on magnetic reconnection, finding that changes in colder ion density and warmer/colder ion ratio can significantly impact reconnection rates and dynamics.
Article
Astronomy & Astrophysics
Shu-Di Yang, Liang Wang, Chuanfei Dong
Summary: This article reports the first fully kinetic simulations of collisionless reconnection in a three-species dusty plasma with negatively charged dust grains, discovering the double Hall pattern and analyzing the reconnection rate. This study is significant for explaining observations of planetary magnetospheres and astrophysical objects, as well as for laboratory studies of dusty plasmas.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Physics, Fluids & Plasmas
Amirhassan Chatraee Azizabadi, Neeraj Jain, Joerg Buechner
Summary: The article characterizes current sheets forming in an ion-kinetic turbulent collisionless plasma using results from two-dimensional hybrid-kinetic numerical simulations. The algorithm parameters are analyzed for their impact on identifying current sheets in plasma turbulence, with appropriate values chosen for identification. Current sheets are statistically characterized in terms of their main properties, showing a tendency to thin down until numerical dissipation stops further thinning.
PHYSICS OF PLASMAS
(2021)
Review
Astronomy & Astrophysics
H. Ji, J. Yoo, W. Fox, M. Yamada, M. Argall, J. Egedal, Y. -h. Liu, R. Wilder, S. Eriksson, W. Daughton, K. Bergstedt, S. Bose, J. Burch, R. Torbert, J. Ng, L. -j. Chen
Summary: 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. The physics foundation of fast reconnection in collisionless plasmas has been largely established, and future opportunities based on multiscale experiments and space missions are discussed.
SPACE SCIENCE REVIEWS
(2023)
Article
Astronomy & Astrophysics
Jia Nan, Kai Huang, Quanming Lu, San Lu, Rongsheng Wang, Jinlin Xie, Jian Zheng, Shui Wang
Summary: In this paper, the formation of electron inflow towards the X-line in magnetic reconnection is analyzed through fluid perspective. It is found that both parallel electric field and mirror force play important roles in driving the electron inflow, with the parallel electric field contributing more significantly. The effects of plasma density and temperature on the formation of electron inflow are also investigated.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Yan Yang, William H. Matthaeus, Sohom Roy, Vadim Roytershteyn, Tulasi N. Parashar, Riddhi Bandyopadhyay, Minping Wan
Summary: The dissipative mechanism in weakly collisional plasma has been the subject of study for decades without a consensus solution. This research compares several energy dissipation estimates and provides theoretical justification for the pressure-strain interaction as a direct estimate of the energy dissipation rate. The results show that the pressure-strain interaction accurately balances the dissipation rate at kinetic scales, while the widely used Yaglom relation may be questionable in some cases.
ASTROPHYSICAL JOURNAL
(2022)
Article
Physics, Fluids & Plasmas
C. Granier, E. Tassi, D. Borgogno, D. Grasso
Summary: This study derives and analyzes the dispersion relation for the growth rate of collisionless tearing modes driven by electron inertia in a strong guide field regime, taking into account equilibrium electron temperature anisotropy. The derived dispersion relation does not show an enhancement of the growth rate as the ratio between perpendicular and parallel equilibrium electron temperatures increases, indicating a significant difference compared to cases with absent or moderate guide field. In the strong guide field regime, the tearing mode is found to become weakly damped as the ratio Theta (e) increases, showing good quantitative agreement with numerical simulations.
PHYSICS OF PLASMAS
(2021)
Article
Physics, Multidisciplinary
Alain Ghizzo, Daniele Del Sarto, Homam Betar
Summary: In this study, we conducted high-resolution kinetic simulations of interpenetrating plasma beams. We found that this configuration is unstable to Weibel-type and two-stream instabilities, which linearly induce a growth of magnetic and electrostatic energy, respectively, at the expense of kinetic energy. We also discovered the possibility of a reversal of energy flow associated with these beam-plasma instabilities with the excitation of secondary propagating oblique modes.
PHYSICAL REVIEW LETTERS
(2023)
Article
Astronomy & Astrophysics
Dario Borgogno, Daniela Grasso, Beatrice Achilli, Massimiliano Rome, Luca Comisso
Summary: In collisionless plasmas, the formation of plasmoids driven by magnetic reconnection is analyzed. It is found that the coexistence of plasmoid formation and Kelvin-Helmholtz instability is present due to the strong velocity shears. Depending on the local values of the magnetic and velocity fields, the current density layers experience plasmoid or KH instability. The competition among these instabilities affects the evolution of current sheets and the difference in energy cascade between magnetic and kinetic spectra.
ASTROPHYSICAL JOURNAL
(2022)
Article
Physics, Multidisciplinary
Alain Ghizzo, Daniele Del Sarto, Homan Betar
Summary: We perform simulations to study the interpenetrating plasma beams, which are susceptible to Weibel-type and two-stream instabilities. We find that the energy flow associated with beam-plasma instabilities can be reversed when secondary propagating oblique modes are excited. This reversal is caused by the reinforcement of the filamentation process in the phase space.
PHYSICAL REVIEW LETTERS
(2023)
Article
Astronomy & Astrophysics
Neeraj Jain, Jorg Buechner, Horia Comisel, Uwe Motschmann
Summary: The unsolved issue of collisionless dissipation of macroscopic energy into heat in space and astrophysical plasmas is discussed, revealing the formation of kinetic scale current sheets in turbulent plasmas. The instabilities in these current sheets are shown to provide collisionless dissipation and influence turbulence, with spatial gradients and non-Maxwellian velocity distributions providing free energy sources. Simulation results support the formation of ion-scale current sheets primarily by electron shear flows, with significant variations in electron and ion flow vorticities within these sheets.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Yukang Shu, San Lu, Quanming Lu, Weixing Ding, Shui Wang
Summary: Collisionless magnetic reconnection is common in space plasma environments, with the reconnection site being unstable and generating reconnection fronts. Energy conversion mainly occurs at the reconnection fronts, while the reconnection rate only represents the energy conversion at the reconnection site.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Marco A. Villagran, P. F. Velazquez, D. O. Gomez, E. B. Giacani
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2020)
Article
Geosciences, Multidisciplinary
G. Boscoboinik, C. Bertucci, D. Gomez, L. Morales, C. Mazelle, J. Halekas, J. Gruesbeck, D. Mitchell, B. Jakosky, E. Penou
GEOPHYSICAL RESEARCH LETTERS
(2020)
Article
Astronomy & Astrophysics
S. Y. Huang, F. Sahraoui, N. Andres, L. Z. Hadid, Z. G. Yuan, J. S. He, J. S. Zhao, S. Galtier, J. Zhang, X. H. Deng, K. Jiang, L. Yu, S. B. Xu, Q. Y. Xiong, Y. Y. Wei, T. Dudok de Wit, S. D. Bale, J. C. Kasper
Summary: The study shows an inverse correlation between power amplitude and spectral steepness at sub-ion scales in solar wind turbulence, as well as a similar trend between steep spectra and increasing normalized cross helicity. It also discusses the ubiquitous nature of the ion transition range in the inner heliosphere.
ASTROPHYSICAL JOURNAL LETTERS
(2021)
Article
Astronomy & Astrophysics
N. Andres, F. Sahraoui, L. Z. Hadid, S. Y. Huang, N. Romanelli, S. Galtier, G. DiBraccio, J. Halekas
Summary: The compressible energy transfer rate from different heliocentric distances was calculated using PSP, THEMIS, and MAVEN observations, showing moderate increases with respect to the incompressible cascade rate. The impact of plasma compressibility on the total cascade rate was demonstrated, and the results were connected with local ion temperature and solar wind heating.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
M. Brodiano, N. Andres, P. Dmitruk
Summary: The study utilized DNS to investigate the interaction between linear waves and turbulence in the CMHD approach. Through parametric study and analysis of spatiotemporal spectra, linear waves such as Alfven waves were detected and their energy distribution quantified.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
R. Ferrand, F. Sahraoui, S. Galtier, N. Andres, P. Mininni, P. Dmitruk
Summary: Various exact laws governing compressible magnetohydrodynamic and compressible Hall-MHD turbulence have been derived in recent years. These laws not only have fundamental theoretical significance, but also can be used to estimate energy dissipation rate from spacecraft observations to address various problems related to solar wind and magnetospheric plasmas. In this study, numerical simulation data is used to analyze two of these laws, and the results show the equivalence of these laws in the inertial range, and reveal the relationship between the strength of the Hall effect and the amplitude of the cascade rate at sub-ion scales.
ASTROPHYSICAL JOURNAL
(2022)
Article
Computer Science, Interdisciplinary Applications
Mauro Fontana, Pablo D. Mininni, Oscar P. Bruno, Pablo Dmitruk
Summary: This method allows for the evolution of electromagnetic and velocity fields in conducting fluids with non-periodic boundaries. It has a small overhead compared to fast FFT-based pseudospectral methods and is applicable to various boundary conditions, including perfectly conducting walls or vacuum surroundings. By using a spectral Fourier continuation method, it accurately represents all fields and their spatial derivatives, allowing for efficient solution of Poisson equations with different boundaries.
COMPUTER PHYSICS COMMUNICATIONS
(2022)
Article
Physics, Fluids & Plasmas
B. Balzarini, F. Pugliese, P. Dmitruk
Summary: In this study, direct numerical simulations of three-dimensional magnetohydrodynamics with a background magnetic field were performed, and test particles were introduced to explore their behavior in a turbulent electromagnetic environment. The focus was on the electric field terms, particularly the electronic pressure term, which was found to generate parallel acceleration of protons in contrast to the known perpendicular energization. By studying the electric field itself, the structures of the electronic pressure field that produce this parallel acceleration were identified.
PHYSICS OF PLASMAS
(2022)
Article
Physics, Fluids & Plasmas
M. Brodiano, P. Dmitruk, N. Andres
Summary: We investigated the incompressible and compressible magnetohydrodynamic (MHD) energy cascade rates in the solar wind at various distances from the Sun using observations from the Parker Solar Probe mission and exact relations in fully developed turbulence. We found an increase in both the compressible and incompressible cascade rates as we approached the Sun, and the isothermal and polytropic cascade rates increased with increasing plasma compressibility. We also compared two exact relations for different levels of compressibility in the solar wind and observed similar cascade rates within the range of compressibility studied.
PHYSICS OF PLASMAS
(2023)
Article
Physics, Fluids & Plasmas
M. Fontana, P. D. Mininni, P. Dmitruk
Summary: In this study, a high-order numerical investigation is conducted on the dependence of dynamo onset on electromagnetic boundary conditions in convecting Boussinesq flows driven by temperature gradients. It is found that having one or two conducting boundaries greatly facilitates dynamo action. For the mixed boundary condition, the critical magnetic Reynolds number becomes independent of the Rayleigh number for sufficiently large Rayleigh numbers.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Computer Science, Interdisciplinary Applications
Mauro Fontana, Oscar P. Bruno, Pablo D. Mininni, Pablo Dmitruk
COMPUTER PHYSICS COMMUNICATIONS
(2020)
Article
Astronomy & Astrophysics
Laura F. Morales, Pablo Dmitruk, Daniel O. Gomez
ASTROPHYSICAL JOURNAL
(2020)
