Article
Physics, Fluids & Plasmas
Himani Dewan, R. Uma, R. P. Sharma
Summary: This study explores the nonlinear interaction between pump wave and low-frequency ion acoustic wave in magnetized plasma, solving the coupled equations through numerical simulation. The results show the chaotic evolution of KAW and how the dynamics of these two waves are influenced by the plasma beta parameter. The saturated spectra observed are similar to those in various astrophysical scenarios for both low and high beta plasma.
PLASMA PHYSICS AND CONTROLLED FUSION
(2021)
Review
Astronomy & Astrophysics
Maria Fedotova, Dmitry Klimachkov, Arakel Petrosyan
Summary: This article introduces different models and reviews the latest magnetohydrodynamic theories of wave processes in rotating astrophysical plasma, considering important and common properties of astrophysical objects such as compressibility and stratification. It fills the gap in theoretical studies in the field of plasma astrophysics and contributes to improving numerical modeling schemes efficiency.
Review
Multidisciplinary Sciences
Ting Li, Eric Priest, Ruilong Guo
Summary: Magnetic reconnection is a fundamental process in various plasmas, with distinct characteristics in two dimensions compared to three dimensions. The focus here is on three-dimensional reconnection in the plasma environment of the Solar System, particularly solar flares. A new paradigm for solar flares, where three-dimensional reconnection plays a central role, is proposed.
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2021)
Review
Chemistry, Multidisciplinary
Sarah Battat, David A. Weitz, George M. Whitesides
Summary: This review focuses on experimental work on nonlinear phenomena in microfluidics, including oscillations, flow-switching behaviors, and bifurcations. The nonlinear behaviors can be induced by the geometry of channels and the manipulation of elements by flowing fluids. Additionally, intermediate Reynolds numbers, non-Newtonian fluids, and liquid metals also contribute to the nonlinear effects. Practical applications include flow gating, mixing, and particle separations.
Article
Optics
Indraj Singh, R. Uma, R. P. Sharma
Summary: A nonlinear wave-based model is introduced to study the ion-scaled magnetic turbulence in laser-produced plasmas. Numerical simulations and semi-analytical methods are used to investigate the nonlinear evolution of the pump wave and the characteristics of turbulent power spectrum. The results are in good agreement with experimental results and provide important insights into simulating astrophysical phenomena and understanding the physics of magnetic turbulence.
Article
Astronomy & Astrophysics
Hava Turkakin, Ian R. Mann, Robert Rankin
Summary: This study investigates the evolution of the Kelvin-Helmholtz instability (KHI) and magnetohydrodynamic (MHD) wave emission at shear-flow boundaries of magnetized plasmas. It finds that significant MHD wave emission occurs not only during the nonlinear stages but also during the KHI's linear stages. These emitted MHD waves can transport energy away from the local region of shear flow, which may have major implications for the evolution of astrophysical objects characterized by fast plasma flow shears.
ASTROPHYSICAL JOURNAL
(2022)
Article
Chemistry, Analytical
Liyi Gu, Chintan Shah, Ruitian Zhang
Summary: The uncertainties in theoretical atomic data are crucial for accurate plasma diagnostics, especially in astrophysical studies. This study presents a new calculation of the uncertainties in current theoretical ion-impact charge exchange atomic data and X-ray spectra, based on comparisons with existing laboratory data. The results show that the average systematic uncertainties are 35-88% for total cross sections and 57-75% for characteristic line ratios. Model deviation increases as collision energy decreases. The errors in total cross sections further contribute to significant uncertainty in the calculation of ionization balance in low-temperature collisional plasmas. Substantial improvements in the atomic database and dedicated laboratory measurements are needed to obtain current models for the next X-ray spectroscopic mission.
Article
Physics, Multidisciplinary
Matthew Goodbred, Yi-Hsin Liu
Summary: We have developed a first-principles model for the relativistic magnetic reconnection rate in strongly magnetized pair plasmas. Our analysis shows that in the magnetically dominated relativistic regime, the x-line thermal pressure is significantly lower than the upstream magnetic pressure, which leads to the collapse of the magnetic field lines and enables fast reconnection. This result is crucial for understanding various extreme astrophysical environments.
PHYSICAL REVIEW LETTERS
(2022)
Article
Multidisciplinary Sciences
Zhetao Jia, Matteo Secli, Alexander Avdoshkin, Walid Redjem, Elizabeth Dresselhaus, Joel Moore, Boubacar Kante
Summary: Complex networks are crucial in understanding phenomena like collective behavior of spins, neural networks, power grids, and disease spread. Recent studies have used topological phenomena in these networks to maintain system response in the presence of disorder. This article proposes and demonstrates topological structurally disordered systems with enhanced nonlinear phenomena in the topological channels. The construction of the graph and its dynamics significantly increase the rate of topologically protected photon pair generation. Disordered nonlinear topological graphs can enable advanced quantum interconnects, efficient nonlinear sources, and light-based information processing for artificial intelligence.
Article
Engineering, Aerospace
Vladimir A. Sreckovic, Milan S. Dimitrijevic, Ljubinko M. Ignjatovic
Summary: This study investigates the photo-dissociation processes in symmetric and strongly non-symmetric systems involving hydrogen and potassium. The study aims to calculate data for small molecules and molecular state characterizations, as well as obtain corresponding partial and average cross-sections. The research provides spectral absorption rate coefficients for symmetric and strongly non-symmetric cases, which can be used for potential modeling in astrophysical plasma research and laboratory plasma investigation.
ADVANCES IN SPACE RESEARCH
(2023)
Article
Engineering, Chemical
Toshiaki Sakuyama, Yasunori Tanaka
Summary: The thermal polymer-ablation phenomena were investigated through direct irradiation of thermal plasmas to polymer bulk specimens using the inductively coupled thermal plasma (ICTP) technique. Spectroscopic observations and numerical modeling were employed to measure and predict the C-2 vibrational and rotational temperatures, as well as mass and power loss during the ablation process.
PLASMA CHEMISTRY AND PLASMA PROCESSING
(2022)
Review
Multidisciplinary Sciences
Evgeny D. Filippov, Konstantin F. Burdonov, Tatiana A. Pikuz, Igor Yu. Skobelev
Summary: This article provides an overview of the application of X-ray self-emission methods for imaging hydrodynamic astrophysical phenomena in laboratory-scale experiments. The typical diagnostic approaches, their advantages, drawbacks, and application prospects are discussed. The methods prove to be valuable for studying various laboratory astrophysical problems with 2D and even 1D spatial resolution. They reveal the hydrodynamic evolution, spatial shape and structure, as well as important parameters such as electron density and plasma temperature of astrophysical objects and related phenomena, which are crucial for verifying astrophysical models.
Article
Physics, Multidisciplinary
V. I. Berezhiani, Z. N. Osmanov, S. V. Mikeladze
Summary: This study investigates the dynamics of electromagnetic beams carrying angular momentum in degenerate astrophysical electron-positron plasmas. The results show that when the power of the beam exceeds a certain critical value, it breaks up into multiple filaments, eventually forming stable spatial soliton structures with zero field at the center.
Article
Physics, Multidisciplinary
A. Abdikian, S. Vasheghani Farahani
Summary: This study investigates the properties of ion-acoustic solitary waves in plasma structures undergoing rotational motions. The influence of various factors, such as relativistic parameters and temperatures, on the energy packet and instability growth rate of the waves is analyzed. Higher relativistic parameters enhance the instability growth rate, while the ratio of temperatures affects the amplitude-to-width ratio and thus the instability growth rate. The study provides insights into energy transfer in white dwarfs or pulsar magnetospheres.
EUROPEAN PHYSICAL JOURNAL PLUS
(2022)
Review
Astronomy & Astrophysics
Siming Liu, J. Randy Jokipii
Summary: High-energy particles in the Universe can be accelerated to very high energies by electric fields, magnetic fields, and plasma waves in astrophysical plasmas. Various theories of particle acceleration, such as stochastic acceleration by turbulent fields and shock acceleration, have been developed and find applications in different astrophysical contexts. Advances in high-energy astrophysical observations allow for a better understanding of the physical processes in evolving astrophysical environments through analyses of high-energy particle acceleration and radiation characteristics.
FRONTIERS IN ASTRONOMY AND SPACE SCIENCES
(2021)
Article
Astronomy & Astrophysics
J. Schober, A. Brandenburg, I. Rogachevskii
GEOPHYSICAL AND ASTROPHYSICAL FLUID DYNAMICS
(2020)
Article
Meteorology & Atmospheric Sciences
Xiang-Yu Li, Axel Brandenburg, Gunilla Svensson, Nils E. L. Haugen, Bernhard Mehlig, Igor Rogachevskii
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2020)
Article
Astronomy & Astrophysics
N. Kleeorin, N. Safiullin, K. Kuzanyan, I. Rogachevskii, A. Tlatov, S. Porshnev
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2020)
Article
Mechanics
L. Barel, A. Eidelman, T. Elperin, G. Fleurov, N. Kleeorin, A. Levy, I. Rogachevskii, O. Shildkrot
Article
Mechanics
N. Kleeorin, I Rogachevskii, S. Zilitinkevich
Summary: The text presents the energy and flux budget (EFB) closure theory for stably stratified turbulence, revealing maintenance of turbulence by velocity shear and providing expressions for turbulent flux of a passive scalar and anisotropic non-symmetric turbulent diffusion tensor. Strong stratification suppresses the diagonal component of turbulent diffusion tensor in the vertical direction, while the horizontal components remain dominant.
Article
Astronomy & Astrophysics
I Rogachevskii, N. Kleeorin
Summary: The study investigates turbulent transport of radiation in the solar convective zone and finds that the effective penetration length of radiation can be increased several times due to turbulent effects, especially near the solar surface. This increase is attributed to compressibility effects that enhance fluctuations of the radiation absorption coefficient.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Physics, Multidisciplinary
Jennifer Schober, Igor Rogachevskii, Axel Brandenburg
Summary: In magnetized plasmas, asymmetry in the chiral chemical potential leads to an electric current along the magnetic field, generating magnetically dominated turbulence and mean magnetic fields.
PHYSICAL REVIEW LETTERS
(2022)
Article
Mechanics
E. Elmakies, O. Shildkrot, N. Kleeorin, A. Levy, I Rogachevskii, A. Eidelman
Summary: This experimental study investigates the turbulent thermal diffusion of small particles in inhomogeneous and anisotropic stably stratified turbulence. The results show that particles accumulate at the minimum of mean fluid temperature.
Article
Mechanics
I. Shimberg, O. Shriki, O. Shildkrot, N. Kleeorin, A. Levy, I. Rogachevskii
Summary: In this experimental study, the transport of nanoparticles in convective turbulence was investigated. It was found that the joint action of turbulent effects and large-scale circulations, as well as molecular effects, resulted in the accumulation of nanoparticles at the cold wall of the chamber. The mean number density of nanoparticles was observed to decrease exponentially over time. Numerical simulations provided further insights and were in agreement with experimental results.
Article
Astronomy & Astrophysics
N. Kleeorin, I Rogachevskii
Summary: The combined action of plasma's helical motions and non-uniform rotation is a crucial mechanism in the generation of large-scale magnetic fields in the Sun and galaxies. The dynamics of magnetic helicity fluxes plays a significant role in the non-linear saturation of dynamos, preventing catastrophic quenching of the alpha effect. Turbulent magnetic helicity fluxes are produced in the convective zone of the Sun, solar-like stars, and galactic discs. These fluxes include non-gradient and gradient contributions, as well as source terms related to the kinetic alpha effect and large-scale shear.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Mechanics
I. Rogachevskii, N. Kleeorin, S. Zilitinkevich
Summary: The energy- and flux-budget theory is extended to the surface layer in atmospheric convective turbulence, providing analytical expressions for vertical profiles of turbulent characteristics and allowing for modeling applications.
Article
Mechanics
G. Orian, A. Asulin, E. Tkachenko, N. Kleeorin, A. Levy, I. Rogachevskii
Summary: The modification of turbulent heat flux by nonuniform large-scale flows plays a crucial role in the formation of large-scale semi-organized coherent structures in turbulent convection.
Article
Astronomy & Astrophysics
Axel Brandenburg, Igor Rogachevskii, Jennifer Schober
Summary: Small-scale dynamos are important in astrophysics and understanding their behavior is crucial for various observations and theoretical aspects. In this study, the authors show that during the kinematic phase of the dynamo, the cutoff wavenumber of the magnetic energy spectra scales differently than expected for small magnetic Prandtl numbers. However, in the non-linear saturated regime, the behavior changes and the cutoff scale has a different scaling with magnetic Prandtl number.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Jennifer Schober, Igor Rogachevskii, Axel Brandenburg
Summary: The dynamics of magnetic fields in chiral magnetohydrodynamics are studied. It is found that a small-scale chiral dynamo can occur if fluctuations of the chiral chemical potential are correlated on large length scales. The generated magnetic field grows exponentially until the nonlinear backreaction sets in and the dynamo saturates.
Article
Physics, Fluids & Plasmas
I Rogachevskii, N. Kleeorin
Summary: The compressibility effects on turbulent transport of temperature field were investigated using different approaches. Compressibility of fluid flow reduces turbulent diffusivity of mean temperature field, leading to turbulent pumping effect and additional thermal sink. It also results in an increase of mean temperature and turbulent cooling of surrounding fluid.
