Article
Astronomy & Astrophysics
Yongyuan Yi, Y. Pang, Liangjin Song, Runqing Jin, Xiaohua Deng
Summary: We investigate the energy conversion in the turbulent region downstream of the reconnection front through 2.5D particle-in-cell simulations. Our findings reveal that a significant amount of magnetic energy is transferred into plasma both in the exhaust region and the turbulent region, which is formed due to the electron Kelvin-Helmholtz instability. Unlike the energy conversion in the exhaust region, the energy conversion in the turbulent region is mainly balanced by its in-plane component. Furthermore, the time evolution of the integrated energy conversion in the turbulent region is strongly correlated with the electron Kelvin-Helmholtz instability and secondary reconnection. The energy is transferred to ions through a nonideal electric field associated with the electron vortices formed during the development of the instability.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Reka M. Winslow, Camilla Scolini, Noe Lugaz, Nathan A. Schwadron, Antoinette B. Galvin
Summary: This study discusses how the type of magnetic reconnection in the inner heliosphere affects the contribution time of CMEs to the heliospheric flux budget, and proposes criteria to distinguish between different types of reconnection. The validity of these criteria is verified through example events. Studying the reconnection and opening of CMEs in the inner heliosphere provides important insights into their role in the heliospheric flux budget and the evolution of their complexity, connectivity, and topology.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
S. E. Milan, M. K. Mooney, G. E. Bower, M. G. G. T. Taylor, L. J. Paxton, I. Dandouras, A. N. Fazakerley, C. M. Carr, B. J. Anderson, S. K. Vines
Summary: We investigated a 15-day period in October 2011 and found weak cusp-aligned arc (CAA) emissions in the polar regions when the interplanetary magnetic field (IMF) clock angle was small. Simultaneous observations of ions and electrons showed that dense plasma was observed even far from the equatorial plane of the tail. We interpret the observations as evidence of trapped plasma on closed field lines, suggesting that the magnetosphere was almost entirely closed during these periods.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Physics, Multidisciplinary
Yuta Murakami, Kento Uchida, Akihisa Koga, Koichiro Tanaka, Philipp Werner
Summary: This article reveals the significant effect of strong spin-charge coupling on high-harmonic generation in Mott insulators. The study shows that the HHG signal is greatly enhanced with decreasing temperature, which is an anomalous behavior due to a cooperative effect between the spin-charge coupling and the thermal ensemble, as well as the temperature-dependent coherence between charge carriers. The research argues that the peculiar temperature dependence of HHG is a generic feature of Mott insulators and can be controlled through the Coulomb interaction and dimensionality of the system.
PHYSICAL REVIEW LETTERS
(2022)
Article
Astronomy & Astrophysics
B. L. Burkholder, K. Nykyri, X. Ma
Summary: The study presents observations of high-energy electrons trapped in diamagnetic cavities, supporting the concept of local acceleration in the reconnection quasi-potential. The pitch angles of particles become increasingly closer to 90 degrees with increasing energy, and the formation of each diamagnetic cavity is related to prevailing solar wind conditions.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Kun Bai, Yiqun Yu, Huishan Fu, Fan Gong, Jinbin Cao
Summary: Magnetic flux ropes (MFRs) are helical structures in the solar-terrestrial space that play a crucial role in particle acceleration and energy transport. This study uses numerical models and simulations to demonstrate that large-scale MFRs can lead to ion acceleration and bring energetic plasma into the inner magnetosphere.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
S. Y. Tang, Y. C. Zhang, L. Dai, T. Chen, C. Wang
Summary: This paper investigates the structure of out-of-plane magnetic field in a reconnection event observed at the magnetopause of the Earth magnetosphere, revealing the unique features of hexapolar Hall magnetic field and providing a comprehensive description of these features. The study offers significant evidence of the hexapolar Hall magnetic field in collisionless magnetic reconnection, providing insights into the Hall effect in such processes.
ASTROPHYSICAL JOURNAL
(2021)
Article
Geosciences, Multidisciplinary
San Lu, Quanming Lu, Rongsheng Wang, Philip L. Pritchett, Mark Hubbert, Yi Qi, Kai Huang, Xinmin Li, C. T. Russell
Summary: A new type of magnetic reconnection, electron-only reconnection without the coupling of ion dynamics, has been observed in space. A two-dimensional particle-in-cell simulation shows that electron-only reconnection in the externally-driven magnetotail is a transition from quiet current sheet to standard reconnection. Based on the simulation results, two criteria are proposed for identifying electron-only reconnection in spacecraft observations, and it is confirmed that the MMS 17 June 2017 event is an electron-only reconnection event in the magnetotail.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Astronomy & Astrophysics
Y. Y. Wei, S. Y. Huang, K. Jiang, Z. G. Yuan, S. B. Xu, J. Zhang, Q. Y. Xiong, Z. Wang, R. T. Lin, L. Yu, Y. Y. Li, C. M. Wang, G. J. Song
Summary: Our study performs a direct quantitative analysis to reveal the acceleration process of energetic electrons at the dipolarization front (DF) using high-time-resolution data. The analysis shows that these electrons at the front could be locally accelerated to over 100 keV by betatron acceleration. The temperature anisotropy formed via the betatron mechanism provides the free energy to excite whistler waves at the DF. Our study provides strong direct evidence for the local electron acceleration at the DF for the first time.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Z. Wang, A. Vaivads, H. S. Fu, J. B. Cao, Y. Y. Liu
Summary: In this paper, a comparative study of flux ropes observed during turbulent reconnection in the Earth's magnetotail is presented. It is found that the farther the flux rope is from the X-line, the larger its size and the slower its movement. The dominant electron acceleration mechanism at all the flux ropes is the betatron mechanism.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
D. B. Korovinskiy, S. A. Kiehas, E. V. Panov, V. S. Semenov, N. V. Erkaev, A. V. Divin, I. V. Kubyshkin
Summary: This study focuses on the reconstruction of magnetic configuration in the magnetic reconnection electron diffusion region, introducing a new reconstruction model independent of divergence of the electron pressure tensor and reconnection electric field. The model is tested on a magnetotail reconnection event observed by the MMS spacecraft, showing improved accuracy in electron velocity reconstruction and suggesting a new technique to estimate the guide field based on magnetic potential reconstruction. The study highlights the significance of electron inertia in the physics of the electron diffusion region, leading to considerable improvement in reconstruction accuracy.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Geosciences, Multidisciplinary
Drew L. Turner, Ian J. Cohen, Samuel T. Bingham, Grant K. Stephens, Mikhail I. Sitnov, Barry H. Mauk, Richard E. Denton, Trevor W. Leonard, Joseph F. Fennell, J. Bernard Blake, Roy B. Torbert, James L. Burch
Summary: The study utilized data from NASA's MMS mission to investigate the behavior of very energetic electrons near special sites where magnetic field lines break and merge. Unexpected features in the electron distributions were found, indicating how changing magnetic topology may result in coherent scattering and acceleration of electrons.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Optics
Ziguang Lin, Yiheng Lin, Wei Yi
Summary: This paper proposes a theoretical scheme that significantly impacts the external motion of a single trapped ion through the non-Hermitian skin effect (NHSE) and demonstrates its competition and potential applications.
Article
Geosciences, Multidisciplinary
Yash Sarkango, James A. Slavin, Xianzhe Jia, Gina A. DiBraccio, Daniel J. Gershman, John E. P. Connerney, William S. Kurth, George B. Hospodarsky
Summary: Two small ion-inertial scale magnetic flux ropes were identified in the Juno magnetic field measurements in Jupiter's magnetotail. These structures could potentially play a significant role in mass loss through plasmoid ejection in the magnetosphere, highlighting the differences in magnetic reconnection processes between Jupiter and other magnetized planets like Earth and Mercury. Further studies are needed to fully understand the implications of these small-scale flux ropes on Jupiter's magnetospheric dynamics.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Lei Wang, Can Huang, Aimin Du, Yasong Ge, Guo Chen, Jinqiao Fan, Jipeng Qin
Summary: This study investigates the characteristics of the Martian tail current sheet based on data from the Mars Atmosphere and Volatile EvolutioN spacecraft. The research reveals that approximately 15% of the current sheet events on Mars display reconnection signatures, happening more frequently than on Earth. The high occurrence rate can be attributed to the extremely thin structure of the Martian tail current sheet, which is on the scale of protons. Magnetic reconnection in the current sheet may impact the evolution of the Martian atmosphere by driving high fluxes of hydrogen ions.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Physics, Fluids & Plasmas
B. A. Wetherton, A. Le, J. Egedal, C. Forest, W. Daughton, A. Stanier, S. Boldyrev
Summary: The drift kinetic model presented in this study addresses the free expansion of a thermal plasma from a magnetic nozzle, incorporating trapped and passing orbit types in the mirror expander geometry. It confirms with data from a fully kinetic simulation and is extended to account for a population of fast sloshing ions arising from neutral beam heating within a magnetic mirror.
PHYSICS OF PLASMAS
(2021)
Article
Instruments & Instrumentation
D. B. Schaeffer, W. Fox, M. J. Rosenberg, H-S Park, G. Fiksel, D. Kalantar
Summary: This study presents measurements of spatially and temporally resolved electron temperature in high-energy-density plasmas using gated x-ray pinhole imagers. By comparing the attenuated signal through different filter materials, a spatially resolved electron temperature as low as 0.1 keV can be estimated. Furthermore, imaging from different directions has a negligible effect on temperature estimates.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2021)
Article
Physics, Fluids & Plasmas
P-A Gourdain, M. Evans, P. Efthimion, R. Ellis, W. Fox, H. R. Hasson, H. Ji, R. Shapovalov, J. R. Young, I West-Abdallah
Summary: Linear transformer drivers can generate mega-amperes quickly using magnetic cores, providing fast charging and discharging capabilities at the cost of increased weight and footprint. This article introduces an alternative approach using insulating breaks instead of magnetic cores to achieve capacitive isolation, reducing weight and footprint while minimizing current losses.
IEEE TRANSACTIONS ON PLASMA SCIENCE
(2021)
Article
Physics, Fluids & Plasmas
G. Fiksel, W. Fox, M. J. Rosenberg, D. B. Schaeffer, J. Matteucci, A. Bhattacharjee
Summary: Electron energization during merging of magnetized plasmas was studied by colliding two plasma plumes with self-generated magnetic fields. Results showed that electrons in merging experiments were additionally accelerated compared to single-plume shots, with energies increased by 50-100 keV.
JOURNAL OF PLASMA PHYSICS
(2021)
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
Optics
Sophia Malko, Courtney Johnson, Derek B. Schaeffer, William Fox, Gennady Fiksel
Summary: We present a design and implementation of proton deflectometry using an in situ reference X-ray image of a mesh to precisely measure non-uniform magnetic fields in expanding plasmas. The technique has been developed using proton and X-ray sources generated from capsule implosions and laser-solid interactions. Our results demonstrate that using a high Z mesh with a large grid spacing can significantly enhance the image contrast, leading to improved accuracy in magnetic field measurement compared to previous demonstrations.
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
Jongsoo Yoo, Yibo Hu, Jeong-Young Ji, Hantao Ji, Masaaki Yamada, Aaron Goodman, Kendra Bergstedt, William Fox, Andrew Alt
Summary: We have developed a local, linear theoretical model for lower hybrid drift waves in weakly collisional plasmas and studied the wave characteristics and collision effects in two different cases.
PHYSICS OF PLASMAS
(2022)
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
Instruments & Instrumentation
C. L. Johnson, S. Malko, W. Fox, D. B. Schaeffer, G. Fiksel, P. J. Adrian, G. D. Sutcliffe, A. Birkel
Summary: We present a technique called proton deflectometry for precise measurements of magnetic fields in high-energy-density plasmas. This technique uses a grid and an in situ reference x-ray grid image to infer the line-integrated magnetic fields. The experimental results verify the effectiveness of this technique in measuring a nonuniform magnetic field and observing the interaction between an expanding plasma plume and the magnetic field.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2022)
Article
Geosciences, Multidisciplinary
T. D. Phan, J. L. Verniero, D. Larson, B. Lavraud, J. F. Drake, M. Oieroset, J. P. Eastwood, S. D. Bale, R. Livi, J. S. Halekas, P. L. Whittlesey, A. Rahmati, D. Stansby, M. Pulupa, R. J. MacDowall, P. A. Szabo, A. Koval, M. Desai, S. A. Fuselier, M. Velli, M. Hesse, P. S. Pyakurel, K. Maheshwari, J. C. Kasper, J. M. Stevens, A. W. Case, N. E. Raouafi
Summary: This article reports the observation of reconnection exhausts in the Heliospheric Current Sheet (HCS) by the Parker Solar Probe at close proximity to the Sun. These exhausts accelerated protons and increased their energy, while also causing the leakage of separatrix field lines.
GEOPHYSICAL RESEARCH LETTERS
(2022)
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
Instruments & Instrumentation
Sayak Bose, William Fox, Dingyun Liu, Zheng Yan, George McKee, Aaron Goodman, Hantao Ji
Summary: This study presents methods for analyzing Beam Emission Spectroscopy (BES) data to obtain the plasma density evolution associated with rapid sawtooth crash events at the DIII-D tokamak. The researchers developed a method to remove sawtooth-induced edge-light pulses in the BES data and performed a cross-calibration of 64 BES channels for accurate measurements. By using a nonlinear relationship, the study revealed large-amplitude density oscillations during the sawtooth events and significant spatial variations near the inversion layer.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2022)
Article
Physics, Multidisciplinary
B. F. Kraus, Lan Gao, W. Fox, K. W. Hill, M. Bitter, P. C. Efthimion, A. Moreau, R. Hollinger, Shoujun Wang, Huanyu Song, J. J. Rocca
Summary: This study presents the first measurements of bulk ion velocity distributions during the initiation of solid ablation under ultrarelativistic laser intensities. Bayesian analysis reveals that bulk ions are either stationary or flowing outward at the plasma sound speed. The results quantitatively constrain the laser-plasma ablation mechanism, suggesting that a steplike electrostatic potential structure drives solid disassembly.
PHYSICAL REVIEW LETTERS
(2022)
