Article
Geosciences, Multidisciplinary
K. Jiang, S. Y. Huang, Z. G. Yuan, Q. Y. Xiong, Y. Y. Wei
Summary: With high-resolution data from the MMS mission, a tilted ion-scale flux rope is observed in the tailward outflow of a magnetic reconnection in the terrestrial magnetotail, indicating the extension of the X-line in the dawn-dusk direction. The observed electron vortex embedded in the flux rope generates an induced magnetic field with the same direction as the axial component, contributing to the enhancement of the magnetic flux carried by the flux rope.
GEOPHYSICAL RESEARCH LETTERS
(2023)
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
Geosciences, Multidisciplinary
Minna Palmroth, Tuija I. Pulkkinen, Urs Ganse, Yann Pfau-Kempf, Tuomas Koskela, Ivan Zaitsev, Markku Alho, Giulia Cozzani, Lucile Turc, Markus Battarbee, Maxime Dubart, Harriet George, Evgeniy Gordeev, Maxime Grandin, Konstantinos Horaites, Adnane Osmane, Konstantinos Papadakis, Jonas Suni, Vertti Tarvus, Hongyang Zhou, Rumi Nakamura
Summary: Rapid plasma eruptions release tremendous energy within Earth's magnetosphere, at the Sun and other planets. The exact mechanism leading to these eruptions, called plasmoids, has been a long-standing question in space physics. Two competing paradigms, magnetic reconnection and kinetic instabilities, have been proposed to explain the process.
Article
Physics, Multidisciplinary
Yilan Qin, Jiayu Ma, Mingle Jiang, Chuanfei Dong, Haiyang Fu, Liang Wang, Wenjie Cheng, Yaqiu Jin
Summary: In this paper, a multimoment fluid model with an implicit fluid closure included in the neural network is constructed using machine learning. The model is trained with a small fraction of sparsely sampled data from kinetic simulations and accurately reproduces the time evolution of the electric field energy and plasma dynamics. A variant of the gPINN architecture, gPINNp, is also introduced to capture the Landau damping process.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Geosciences, Multidisciplinary
H. Gurram, J. Egedal, W. Daughton
Summary: This study found that shear Alfven waves (SAWs) can efficiently transport wave energy during magnetic reconnection in the magnetotail, greatly enhancing the energy input for the Aurora Borealis compared to previous estimates.
GEOPHYSICAL RESEARCH LETTERS
(2021)
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
Physics, Fluids & Plasmas
N. Bessho, L. -J. Chen, J. E. Stawarz, S. Wang, M. Hesse, L. B. Wilson, J. Ng
Summary: Turbulent magnetic reconnection in a quasi-parallel shock under parameters relevant to the Earth's bow shock is investigated. The study shows the generation of current sheets in the shock transition region, where electron-only reconnection or reconnection involving both ions and electrons can occur. The outflow speeds of electrons and ions can reach high values, resulting in a larger reconnection electric field compared to standard reconnection processes.
PHYSICS OF PLASMAS
(2022)
Article
Geosciences, Multidisciplinary
Yongyuan Yi, Meng Zhou, Liangjin Song, Ye Pang, Xiaohua Deng
Summary: This study reveals the existence of electron-only magnetic reconnection during magnetic island coalescence, which is the early stage of the process. During this electron-only reconnection, ions are affected by the reconnection electric field although the ion bulk outflow is absent.
GEOPHYSICAL RESEARCH LETTERS
(2022)
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
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
J. Stewart, P. K. Browning, M. Gordovskyy
Summary: This paper presents 2D magnetohydrodynamic simulations to investigate key issues in oscillatory reconnection, including intrinsic oscillatory reconnection during flux rope coalescence, wave generation after coalescence, and the dependence of wave characteristics on the initial magnetic field. The results show that the properties of the waves emitted during flux rope coalescence could be used as a diagnostic tool to determine physical parameters within a coalescing region.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Physics, Fluids & Plasmas
Jiong-Hang Liang, Tian-Xing Hu, D. Wu, Zheng-Mao Sheng
Summary: Classical plasmas are characterized by low density and/or high temperature, exhibiting Landau damping and two-stream instabilities. When plasma density increases, quantum effects come into play, causing beam-plasma interactions to behave differently from classical cases. Under certain conditions where quantum hydrodynamic and kinetic theories apply, the instability growth rate may resemble pure two-stream instability without Landau damping when the velocity threshold is exceeded, in contrast to classical behavior.
Article
Astronomy & Astrophysics
Xinmin Li, Rongsheng Wang, Can Huang, Quanming Lu, San Lu, J. L. Burch, Shui Wang
Summary: This study establishes a quantitative relationship between energy conversion and current density in turbulent plasma based on Magnetospheric Multiscale mission data. The results reveal that magnetic energy is primarily released in the perpendicular directions, and ions acquire most of the released energy in weak current regions, while electrons significantly energize in strong currents.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Jiayan Yang, Junchao Hong, Bo Yang, Yi Bi, Zhe Xu
Summary: Different from the classical emerging-flux model, recent studies propose that solar coronal jets are triggered by minifilament eruptions and involve two magnetic reconnection processes, namely external and internal reconnections. Observational signatures of these two reconnection processes are presented for a solar coronal jet, triggered by a minifilament eruption in a coronal hole, using data from the Solar Dynamics Observatory. Weak bidirectional outflows and a flare current sheet are observed, corresponding to the external and internal reconnections, respectively.
ASTROPHYSICAL JOURNAL
(2023)
Article
Geosciences, Multidisciplinary
Hongtao Huang, Yanting Hu, Yongli Ping, Tongpu Yu
Summary: Through particle-in-cell simulations, scientists have successfully created electron-only magnetic reconnection via laser-plasma interactions. In this process, the reconnection current sheet is primarily carried by electrons, while the ion outflow is negligible. By investigating the energy conversion during the reconnection, researchers found that the reconnection electric field plays a crucial role.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Astronomy & Astrophysics
K. Keika, S. Kasahara, S. Yokota, M. Hoshino, K. Seki, T. Amano, L. M. Kistler, M. Nose, Y. Miyoshi, T. Hori, I. Shinohara
Summary: During magnetic storms, O+ ions play a significant role in plasma pressure in the inner magnetosphere. Heavier ions are more energized than lighter ions, and lower-charge-state ions are more energized than higher-charge-state ions. The preferential energization is due to temperature increases rather than the generation of energetic ions in the high-energy tail.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Takanobu Amano, Masahiro Hoshino
Summary: This article presents a theory of electron injection into diffusive shock acceleration (DSA) for the generation of cosmic-ray electrons at collisionless shocks. The theory suggests that stochastic shock drift acceleration (SSDA) can be understood as a diffusive particle acceleration mechanism at an oblique shock of finite thickness. It also shows that SSDA is more efficient for low-energy electron acceleration and is favorable for injection. The theory further indicates that efficient acceleration of electrons to ultrarelativistic energies is more easily achieved at high Mach number, young supernova remnant shocks, but not at weak or moderate shocks in the heliosphere unless the upstream magnetic field is nearly perpendicular to the shock normal.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Yuhei Umeda, Keiya Fukui, Toshimori Sekine, Marco Guarguaglini, Alessandra Benuzzi-Mounaix, Nobuki Kamimura, Kento Katagiri, Ryosuke Kodama, Takeshi Matsuoka, Kohei Miyanishi, Alessandra Ravasio, Takayoshi Sano, Norimasa Ozaki
Summary: This study highlights the importance of understanding the physical properties of carbonate minerals under extreme conditions for comprehending the dynamic behaviors of planets and their mantle structures. The findings provide valuable insights for theoretical models considering extreme conditions.
Article
Physics, Fluids & Plasmas
Masahiro Hoshino
Summary: The efficiency of nonthermal particle acceleration during magnetic reconnection has been a long-standing question in astrophysics. Recent studies have shown that the production of nonthermal particles becomes more efficient with increasing plasma temperature.
PHYSICS OF PLASMAS
(2022)
Article
Physics, Fluids & Plasmas
G. Rigon, B. Albertazzi, P. Mabey, Th. Michel, P. Barroso, A. Faenov, R. Kumar, C. Michaut, T. Pikuz, Y. Sakawa, T. Sano, H. Shimogawara, S. Tamatani, A. Casner, M. Koenig
Summary: This paper presents the effects of a radiative shock on the morphology of jet-like objects subjected to hydrodynamic instabilities. The experimental observations suggest that a radiative shock has opposite effects on instability growth, with its deceleration enhancing the growth but the produced radiations tending to stabilize the interfaces.
PHYSICS OF PLASMAS
(2022)
Article
Optics
Sadaoki Kojima, Yuki Abe, Eisuke Miura, Tetsuo Ozaki, Kohei Yamanoi, Tomokazu Ikeda, Yubo Wang, Jinyuan Dun, Shuwang Guo, Tamaki Maekawa, Ryunosuke Takizawa, Hiroki Morita, Shoui Asano, Yasunobu Arikawa, Hiroshi Sawada, Katsuhiro Ishii, Ryohei Hanayama, Shinichiro Okihara, Yoneyoshi Kitagawa, Yasuhiro Kajimura, Alessio Morace, Hiroyuki Shiraga, Keisuke Shigemori, Atsushi Sunahara, Natsumi Iwata, Takayoshi Sano, Yasuhiko Sentoku, Tomoyuki Johzaki, Masaharu Nishikino, Akifumi Iwamoto, Kenichi Nagaoka, Hitoshi Sakagami, Shinsuke Fujioka, Yoshitaka Mori
Summary: In this study, a counter-propagating laser beam platform using a spherical plasma mirror was developed and evaluated for high-energy lasers. The performance of the plasma mirror was assessed by measuring parameters such as reflectivity and peak intensity. The platform enables the study of counter-streaming charged particles in high-energy-density plasmas.
Article
Physics, Fluids & Plasmas
K. Sakai, T. Nishimoto, S. Isayama, S. Matsukiyo, Y. Kuramitsu
Summary: In this study, the ion-acoustic features of collective Thomson scattering (CTS) in two-stream plasmas are investigated both theoretically and numerically. The theoretical spectrum shows asymmetry when the electron distribution functions of the stationary and moving components overlap with each other at the phase velocities corresponding to the two resonant peaks. Numerical simulations confirm the theoretical spectra and also demonstrate the effect of a two-stream-type instability in the ion-acoustic feature. The results highlight the significant effects of two-stream plasmas on CTS spectra and the observation of waves resulting from instabilities in the ion-acoustic feature.
PHYSICS OF PLASMAS
(2023)
Article
Astronomy & Astrophysics
S. Isayama, K. Takahashi, S. Matsukiyo, T. Sano
Summary: Counterpropagating Alfven waves are commonly observed in various astrophysical environments and can efficiently accelerate particles. Phase transitions of particle behavior occur when wave amplitudes exceed critical values, resulting in irreversible relativistic energy gain for particles. The accelerated particles have spatial coherence. The findings may have implications for astrophysical phenomena and future laboratory experiments using high-power lasers.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Masahiro Hoshino
Summary: In the process of magnetic reconnection, nonthermal plasma can dominate the total kinetic energy density with more than 90%. Strengthening the guide magnetic field can suppress the efficiency of nonthermal particle acceleration.
ASTROPHYSICAL JOURNAL
(2023)
Article
Physics, Fluids & Plasmas
Yasuhiro Kuramitsu, Yosuke Matsumoto, Takanobu Amano
Summary: The Weibel instability is investigated using relativistic intense short laser pulses, which can generate sub-relativistic high-density collisionless plasmas. By irradiating double parallel planar targets with two relativistic laser pulses, sub-relativistic collisionless counterstreaming plasmas are created.
PHYSICS OF PLASMAS
(2023)
Article
Physics, Fluids & Plasmas
Masayasu Hata, Takayoshi Sano, Natsumi Iwata, Yasuhiko Sentoku
Summary: Advances in laser technology have led to increased laser intensities, making it necessary to accurately treat the relativistic rising edge component. A double-layer target has been found to improve proton acceleration efficiency, and this design can be optimized using two-dimensional particle-in-cell simulations.
Article
Engineering, Electrical & Electronic
Kirolosse M. Girgis, Tohru Hada, Shuichi Matsukiyo, Akimasa Yoshikawa
Summary: The radiation environment of LEO spacecraft passing through the South Atlantic Anomaly during a geomagnetic storm event in May 2005 was studied. It was found that during the recovery phase of the geomagnetic storm, the southern proton flux in the SAA increased, resulting in significantly higher SEU rates and absorbed radiation doses.
IEEE JOURNAL OF RADIO FREQUENCY IDENTIFICATION
(2022)
Article
Physics, Fluids & Plasmas
R. Yamazaki, S. Matsukiyo, T. Morita, S. J. Tanaka, T. Umeda, K. Aihara, M. Edamoto, S. Egashira, R. Hatsuyama, T. Higuchi, T. Hihara, Y. Horie, M. Hoshino, A. Ishii, N. Ishizaka, Y. Itadani, T. Izumi, S. Kambayashi, S. Kakuchi, N. Katsuki, R. Kawamura, Y. Kawamura, S. Kisaka, T. Kojima, A. Konuma, R. Kumar, T. Minami, I Miyata, T. Moritaka, Y. Murakami, K. Nagashima, Y. Nakagawa, T. Nishimoto, Y. Nishioka, Y. Ohira, N. Ohnishi, M. Ota, N. Ozaki, T. Sano, K. Sakai, S. Sei, J. Shiota, Y. Shoji, K. Sugiyama, D. Suzuki, M. Takagi, H. Toda, S. Tomita, S. Tomiya, H. Yoneda, T. Takezaki, K. Tomita, Y. Kuramitsu, Y. Sakawa
Summary: We present an experimental method and simulation results to generate quasiperpendicular supercritical magnetized collisionless shocks, which clarify the structures of plasma density and temperatures.