Article
Astronomy & Astrophysics
Lars K. S. Daldorff, James E. Leake, James A. Klimchuk
Summary: This study investigates the onset and development of the tearing instability using high-fidelity resistive magnetohydrodynamics simulations in 2.5D and 3D. The results show that the primary current sheet in 2.5D fragments due to plasmoids, leading to an increase in the global reconnection rate with the strength of the reconnecting field. In 3D, the presence of interacting oblique modes of the tearing instability complicates the picture and decreases the reconnection rate with increasing reconnecting field. The 3D rates are lower than the 2.5D rates, but suggest convergence as the reconnecting field weakens.
ASTROPHYSICAL JOURNAL
(2022)
Article
Multidisciplinary Sciences
Chuanfei Dong, Liang Wang, Yi-Min Huang, Luca Comisso, Timothy A. Sandstrom, Amitava Bhattacharjee
Summary: Magnetohydrodynamic turbulence plays a crucial role in energy transfer in many astrophysical systems. In our simulations, we discovered that rapid reconnection of magnetic field lines leads to the formation of small magnetic flux ropes, changing the classical paradigm of turbulent energy cascade. This finding has important implications for understanding solar coronal heating and other phenomena.
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
Daniele A. Dias, Francisco W. S. Lima, Joao A. Plascak
Summary: A generalized version of the original Gibbs phase rule is proposed to study phase transitions in lattice spin magnetic models, focusing on single phases, multiphase coexistence, and multicritical phenomena. By counting the thermodynamic number of degrees of freedom and analyzing the phase diagrams of various spin Hamiltonians, including Ising, Blume-Capel, and Potts models, the rule provides a good description of the possible topology of the corresponding phase diagram. Although it cannot locate phase boundaries, it is useful in describing critical and multicritical surfaces, as well as isolated multicritical points.
Article
Astronomy & Astrophysics
Giovanni Lapenta, Martin Goldman, David L. Newman, Stefan Eriksson
Summary: By simulating with 3D particle in cell, we observe the spontaneous formation of turbulent outflows in an initially laminar 3D reconnecting current layer. Many secondary current layers and reconnection sites are formed in the outflow. Smaller current clusters are more prone to reconnecting and releasing energy.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Wenqing Ma, Meng Zhou, Zhihong Zhong, Xiaohua Deng
Summary: This article presents a statistical study on electron acceleration in Earth's magnetotail using in situ satellite observations. The study finds that larger acceleration rates tend to occur in outflows with higher speeds. The mechanisms of betatron and first-order Fermi acceleration are intensified near the neutral sheet, while E (divide divide) acceleration is significant not only near the neutral sheet but also in the separatrix region. The study also suggests that acceleration near the X line is comparable to that in the outflow, contradicting previous studies.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Z. C. Tian, M. Zhou, H. Y. Man, Z. H. Zhong, X. H. Deng, D. J. Gershman, Y. V. Khotyaintsev, C. T. Russell
Summary: This paper presents the simultaneous observation of the inner and outer electron diffusion region (EDR) in magnetic reconnection with a large guide field at the dayside magnetopause by the magnetospheric multiscale (MMS) spacecraft. The inner EDR is characterized by positive J·E', while the outer EDR is manifested by negative J·E' and opposite out-of-plane electric field. The observation of bidirectional accelerated electron jets on the opposite side of the X-line is significant, and the fortuitous formation of MMS provides estimates for the length of the inner EDR and the reconnection rate.
ASTROPHYSICAL JOURNAL
(2023)
Article
Chemistry, Physical
L. L. Bao, H. Yibole, J. Y. Xu, Z. Q. Ou, O. Haschuluu, O. Tegus, N. H. van Dijk, E. Bruck, F. Guillou
Summary: (English Summary:)
This study explores the structural and magnetic phase diagrams of (Fe,Co)(2)(P,Si) compounds, with a focus on the observation range of the hexagonal Fe2P-type structure. It is found that under certain conditions of Si content and Fe substitution for Co, the samples undergo structural distortion and exhibit different crystal structures. Additionally, simultaneous Co substitution for Fe and Si substitution for P helps to observe the hexagonal structure. This study provides guidance for future investigations in determining the desired range of properties for permanent magnetic applications.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Mechanics
Lei Luo, Xiaojun Xu, Yu Zhang, Zilu Zhou, Qing Chang, Qi Xu, Xing Wang, Peishan He, Siqi Yi, Hui Li
Summary: The two-fluid generalized Ohm's law (GOL) is proposed based on the assumption of a plasma consisting of only protons and electrons. The three-fluid GOL is obtained theoretically for the three-fluid plasma consisting of heavy ions, light ions, and electrons, which is found in planetary ionospheres and magnetospheres. The study derives three inertial lengths and explores the modification of ion inertial lengths, reconnection rate, and Hall magnetic and electric fields due to the two-step decoupling process of ions. The findings provide a framework to expand the reconnection theory to include more ion species.
Article
Astronomy & Astrophysics
Wensi Wang, Rui Liu
Summary: By investigating the response of running penumbral waves (RPWs) to the buildup and erosion of erupting magnetic flux ropes (MFRs), it was found that magnetic reconnection in the corona impacts the low atmosphere and leads to changing behaviors of RPWs, offering new insights into diagnosing flare reconnections.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Geosciences, Multidisciplinary
J. M. Schroeder, J. Egedal, G. Cozzani, Yu Khotyaintsev, W. Daughton, R. E. Denton, J. L. Burch
Summary: This study analyzes in-situ spacecraft observations from Earth's magnetotail and maps them onto a 2D spatial domain to study the process of magnetic reconnection. The results show that, despite perturbations from 3D dynamics, the structure of the electron diffusion region remains consistent with 2D kinetic simulation, validating the effectiveness of 2D kinetic and laminar reconnection models.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Physics, Fluids & Plasmas
S. Adhikari, T. N. Parashar, M. A. Shay, W. H. Matthaeus, P. S. Pyakurel, S. Fordin, J. E. Stawarz, J. P. Eastwood
Summary: Using simulations of strong turbulence and reconnection, a study compares the cross-scale transfer of energy in the two systems and finds that the energy transfer structure is very similar in both cases. In the case of reconnection, the time evolution of energy transfer is correlated with the reconnection rate, providing explicit evidence that reconnection dynamics fundamentally involves turbulence-like energy transfer.
Article
Chemistry, Physical
Xinlin Yan, Pavel Broz, Jan Vrestal, Jiri Vlach, Jiri Bursik, Martina Mazalova, Jana Pavlu, Bedrich Smetana, Gerda Rogl, Markus Eiberger, Andriy Grytsiv, Herwig Michor, Herbert Mueller, Gerald Giester, Peter Rogl
Summary: The constitution of the two phase diagrams Nb-Mn and Ta-Mn has been determined using various methods, revealing the characteristics of binary compounds, congruent melting, and eutectic reactions. The detailed distribution of atom sites in the Laves phases has been established.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Geosciences, Multidisciplinary
N. Romanelli, G. A. DiBraccio, R. Modolo, J. E. P. Connerney, R. W. Ebert, Y. M. Martos, T. Weber, J. R. Espley, W. S. Kurth, F. Allegrini, P. Valek, S. J. Bolton
Summary: By using the observations and simulations from Juno's flyby of Ganymede, researchers were able to analyze the moon's magnetosphere and uncover signs of magnetic reconnection.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Nanoscience & Nanotechnology
Wenping Guo, Jiaqi Wang, Dongjian Liu
Summary: The study further investigates the dominant 2D electron-magnetohydrodynamics (EMHD) tearing mode in an electron-skin-depth-scale current sheet (ECS), revealing insignificant resistive diffusion at this scale, expansion of the inner region due to electron inertia, and the invalidity of the boundary layer approximation. Nonlinear evaluation shows a rapid normal saturation transition and growth rate dependence on wave number. Linear analysis of EMHD tearing mode with force-free equilibrium and nonlinear simulation results demonstrate dynamic structures consistent with observations in Earth's turbulent magnetosheath.
Article
Geosciences, Multidisciplinary
R. E. Ergun, L. -J. Chen, F. D. Wilder, N. Ahmadi, S. Eriksson, M. E. Usanova, K. A. Goodrich, J. C. Holmes, A. P. Sturner, D. M. Malaspina, D. L. Newman, R. B. Torbert, M. R. Argall, P. -A. Lindqvist, J. L. Burch, J. M. Webster, J. F. Drake, L. Price, P. A. Cassak, M. Swisdak, M. A. Shay, D. B. Graham, R. J. Strangeway, C. T. Russell, B. L. Giles, J. C. Dorelli, D. Gershman, L. Avanov, M. Hesse, B. Lavraud, O. Le Contel, A. Retino, T. D. Phan, M. V. Goldman, J. E. Stawarz, S. J. Schwartz, J. P. Eastwood, K. -J. Hwang, R. Nakamura, S. Wang
GEOPHYSICAL RESEARCH LETTERS
(2017)
Article
Physics, Multidisciplinary
G. T. Roberg-Clark, J. F. Drake, C. S. Reynolds, M. Swisdak
PHYSICAL REVIEW LETTERS
(2018)
Article
Physics, Fluids & Plasmas
J. F. Drake, H. Arnold, M. Swisdak, J. T. Dahlin
PHYSICS OF PLASMAS
(2019)
Article
Physics, Fluids & Plasmas
Qile Zhang, J. F. Drake, M. Swisdak
PHYSICS OF PLASMAS
(2019)
Article
Physics, Fluids & Plasmas
P. Sharma Pyakurel, M. A. Shay, T. D. Phan, W. H. Matthaeus, J. F. Drake, J. M. TenBarge, C. C. Haggerty, K. G. Klein, P. A. Cassak, T. N. Parashar, M. Swisdak, A. Chasapis
PHYSICS OF PLASMAS
(2019)
Article
Physics, Fluids & Plasmas
H. Arnold, J. F. Drake, M. Swisdak, J. Dahlin
PHYSICS OF PLASMAS
(2019)
Article
Physics, Fluids & Plasmas
Qile Zhang, J. F. Drake, M. Swisdak
PHYSICS OF PLASMAS
(2019)
Article
Astronomy & Astrophysics
L. Price, M. Swisdak, J. F. Drake, D. B. Graham
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2020)
Article
Physics, Multidisciplinary
J. P. Eastwood, M. Goldman, T. D. Phan, J. E. Stawarz, P. A. Cassak, J. F. Drake, D. Newman, B. Lavraud, M. A. Shay, R. E. Ergun, J. L. Burch, D. J. Gershman, B. L. Giles, P. A. Lindqvist, R. B. Torbert, R. J. Strangeway, C. T. Russell
PHYSICAL REVIEW LETTERS
(2020)
Article
Physics, Fluids & Plasmas
M. Xuan, M. Swisdak, J. F. Drake
Summary: The study focuses on the reversibility of energy transfer from the magnetic field to the surrounding plasma during magnetic reconnection. It demonstrates that irreversibility is associated with separatrix crossings and passages through weaker magnetic field regions. The inclusion of a guide field enhances particle magnetization.
PHYSICS OF PLASMAS
(2021)
Article
Physics, Multidisciplinary
P. S. Pyakurel, M. A. Shay, J. F. Drake, T. D. Phan, P. A. Cassak, J. L. Verniero
Summary: Observations in Earth's turbulent magnetosheath downstream of a quasiparallel bow shock reveal a prevalence of electron-scale current sheets favorable for electron-only reconnection where ions are not coupled to the reconnecting magnetic fields. In small-scale turbulence, magnetic structures associated with intense current sheets are limited in all dimensions. The 2D and 3D kinetic particle-in-cell simulations investigate electron-only reconnection, showing a new form of 3D electron-only reconnection with higher reconnection rates.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Fluids & Plasmas
M. Oieroset, T. D. Phan, R. Ergun, N. Ahmadi, K. Genestreti, J. F. Drake, Y-H Liu, C. Haggerty, J. P. Eastwood, M. A. Shay, P. S. Pyakurel, S. Haaland, M. Oka, M. Goodbred, S. Eriksson, J. L. Burch, R. B. Torbert, Y. Khotyaintsev, C. T. Russell, R. J. Strangeway, D. J. Gershman, B. L. Giles
Summary: This study reports observations of a thin reconnecting current sheet within ion inertial lengths, revealing heating characteristics of electrons and ions during the reconnection process, as well as the evolution of magnetic and electric fields.
PHYSICS OF PLASMAS
(2021)
Article
Physics, Fluids & Plasmas
M. Oka, T. D. Phan, M. Oieroset, D. L. Turner, J. F. Drake, X. Li, S. A. Fuselier, D. J. Gershman, B. L. Giles, R. E. Ergun, R. B. Torbert, H. Y. Wei, R. J. Strangeway, C. T. Russell, J. L. Burch
Summary: This study shows that electrons in Earth's magnetotail are energized by the locally averaged electric field magnitude, suggesting the importance of reconnection-driven turbulence. However, the non-thermal power-law component can be small even with a large electric field and significant heating of the bulk population.
PHYSICS OF PLASMAS
(2022)
Article
Astronomy & Astrophysics
M. Opher, J. F. Drake, M. Swisdak, B. Zieger, G. Toth
ASTROPHYSICAL JOURNAL LETTERS
(2017)
Article
Astronomy & Astrophysics
J. F. Drake, M. Swisdak, M. Opher, J. D. Richardson
ASTROPHYSICAL JOURNAL
(2017)