H. Rothermel, T. Hagl, G. E. Morfill, M. H. Thoma, H. M Thomas
Micron sized particles are suspended or even lifted up in a gas by thermophoresis. This allows the study of many processes occurring in strongly coupled complex plasmas at the kinetic level in a relatively stress-free environment. First results are presented. The technique is also of interest for technological applications.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
继续探索
The extreme electromagnetic fields sustained by plasma-based accelerators allow for energy gain rates above 100 GeV/m but are also an inherent source of correlated energy spread. This severely limits the usability of these devices. Here we propose a novel compact concept which compensates the induced energy correlation by combining plasma accelerating stages with a magnetic chicane. Particle-in-cell and tracking simulations of a particular 1.5 m-long setup with two plasma stages show that 5.5 GeV bunches with a final relative energy spread of $1.2\times10^{-3}$ (total) and $5.5\times10^{-4}$ (…
Rayleigh-Taylor and Buoyancy-driven instabilities are very common instabilities for an inhomogeneous medium. We examine here how these instabilities grow for incompressible viscoelastic fluids like a strongly coupled dusty plasma by using incompressible generalized hydrodynamic (i-GHD) fluid model. Since the dust particles are pretty massive, the gravitational attraction of earth has a significant role in its dynamics. In this paper the acceleration due to gravity g and the role of strong coupling in the context of gravitationally stratified dusty plasma fluid have been considered. We find tha…
The fundamental dispersion relation of transverse electro-magnetic waves in a cold collisionless plasma is formally equivalent to the two dimensional dispersion relation of inertio-gravity waves in a rotating shallow water system, where the Coriolis frequency can be identified with the plasma frequency, and the shallow water gravity wave phase speed plays the role of the speed of light. Here we examine this formal equivalence in the governing linearised equations, and compare between the propagation wave mechanisms in these seemingly unrelated physical systems.
In part I (arXiv:2006.12393) (accepted in JPP), we simulated individual dynamics of a rising bubble and a falling droplet in an incompressible limit of a strongly coupled dusty plasma (SCDP) using a generalized hydrodynamic viscoelastic fluid model. In interest to understand hetero- (bubble-drop) interactions between them, we extend this study to their combined evolution through two arrangements: First, both are placed side-by-side in a row at the same height. We observe that the overall dynamic governs by the competition between the rotational motion induces due to the pairing between two co-…
A self-consistent fluid model developed for simulations of micro- gravity dusty plasma experiments has for the first time been used to model asymmetric dusty plasma experiments in a modified GEC reference cell with gravity. The numerical results are directly compared with experimental data and the experimentally determined dependence of global discharge parameters on the applied driving potential and neutral gas pressure is found to be well matched by the model. The local profiles important for dust particle transport are studied and compared with experimentally determined profiles. The radial…
A numerical study of gravity-driven instability in strongly coupled dusty plasma. Part 3: Homo-interaction between a pair of rising/falling bubbles/droplets
本文基于广义流体动力学模型，数值研究了强耦合尘埃等离子体（粘弹性流体）中两下降液滴与两上升气泡的同源相互作用，揭示了重力加速度与靠近效应的竞争机制，并发现剪切波在宽间距下促进配对、近间距下耦合强度抑制运动。
We discuss some general and relevant features of longitudinal gravitational modes in Horndeski gravity and their interaction with matter media. Adopting a gauge-invariant formulation we clarify how massive scalar and vector fields can induce additional transverse and longitudinal excitations, resulting in breathing, vector and longitudinal polarizations. We review, then, the interaction of standard gravitational waves with a molecular medium, outlining the emergence of effective massive gravitons, induced by the net quadrupole moment due to the molecule deformation. Finally, we investigate the…
Collections of micrometer sized solid particles immersed in plamsa are used to mimic many systems from solid state and fluid physics, due to their strong electrostatic interaction, their large inertia, and the fact that they are large enough to be visualized with ordinary optics. On Earth, gravity restricts the so called dusty plasma systems to thin, two-dimensional layers, unless special experimental geometries are used, involving heated or cooled electrons, and/or the use of dielectric materials.In micro-gravity experiments, the formation of a dust-free void breaks the isotropy of three-dime…
A basic concept to calculate physical features of non-ideal plasmas, such as optical properties, is the spectral function which is linked to the self-energy. We calculate the spectral function for a non-relativistic hydrogen plasma in $GW$-approximation. In order to go beyond $GW$ approximation, we include self-energy and vertex correction to the polarization function in lowest order. Partial compensation is observed. The relation of our approach to $GW$ and $GWΓ$ calculations in other fields, such as the band-structure calculations in semiconductor physics, is discussed. From the spectral fun…
We consider cosmological applications of a new self-consistent system of equations, accounting for a nonminimal coupling of the gravitational, electromagnetic and pseudoscalar (axion) fields in a relativistic plasma. We focus on dispersion relations for electromagnetic perturbations in an initially isotropic ultrarelativistic plasma coupled to the gravitational and axion fields in the framework of isotropic homogeneous cosmological model of the de Sitter type. We classify the longitudinal and transversal electromagnetic modes in an axionically active plasma and distinguish between waves (dampi…
Macroscopic plasma polarization, which is created by gravitation and other mass-acting (inertial) forces in massive astrophysical objects is under discussion. Non-ideality effect due to strong Coulomb interaction of charged particles is introduced into consideration as a new source of such polarization. Simplified situation of totally equilibrium isothermal star without relativistic effects and influence of magnetic field is considered. The study is based on variational approach combined with "local density approximation". It leads to two local forms of thermodynamic equilibrium conditions: co…
In this introductory review article, we explore the special relativistic equations of particle motions and the consequent derivation of Einstein's famous formula $E=mc^2$. Next, we study the special relativistic electromagnetic field equations and generalizations of Lorentz equations of motion for charged particles. We then introduce the special relativistic gravitational field as a symmetric second order tensor field. Particle motions in the presence of static gravity are explored which could be used to study planetary dynamics, revealing perihelion shifts. Next, we investigate the system of …
We develop a general theory of buoyancy instabilities in the electron-ion plasma with the electron heat flux based not upon MHD equations, but using a multicomponent plasma approach in which the momentum equation is solved for each species. We investigate the geometry in which the background magnetic field is perpendicular to the gravity and stratification. General expressions for the perturbed velocities are given without any simplifications. Collisions between electrons and ions are taken into account in the momentum equations in a general form, permitting us to consider both weakly and stro…
The plasma force on grains of specified charge and height in a collisional DC plasma sheath are calculated using the multidimensional particle in cell code COPTIC. The background ion velocity distribution functions for the unperturbed sheath vary substantially with collisionality. The grain force is found to agree quite well with a combination of background electric field force plus ion drag force. However, the drag force must take account of the non-Maxwellian (and spatially varying) ion distribution function, and the collisional drag enhancement. It is shown how to translate the dimensionles…
On effective radiational gravity acceleration at the interface of dense plasmas and vacuum
研究了稠密电磁辐射压力下等离子体-真空界面的辐射重力表面波，发现DEMRP通常能稳定表面波但特定条件下会通过摩擦不稳定性增强其增长率，该工作有助于理解中子星等天体系统的重力特性。
Dual Mode Operation of a Hydromagnetic Plasma Thruster to Achieve Tunable Thrust and Specific Impulse
本文研究脉冲磁流体等离子体推力器的预填充与气体喷注双模式，通过气体动力学调控磁爆燃/磁爆轰，实现10–55 km/s排气速度、2600–5600 s比冲及最高31 mN推力的可调性能。
The physics of instabilities in the precursor of relativistic collisionless shocks is of broad importance in high energy astrophysics, because these instabilities build up the shock, control the particle acceleration process and generate the magnetic fields in which the accelerated particles radiate. Two crucial parameters control the micro-physics of these shocks: the magnetization of the ambient medium and the Lorentz factor of the shock front; as of today, much of this parameter space remains to be explored. In the present paper, we report on a new instability upstream of electron-positron …
Resistive instabilities of current sheets in stratified plasmas with a gravitational field
研究了重力场中分层等离子体中电流片的电阻不稳定性，发现不利分层会增强撕裂模式的不稳定性，而有利分层则抑制重联过程。
Two-dimensional plasma crystals are characterized by a strong up-and-down asymmetry not only due to gravity but also due to the presence of plasma flow at the location of particles. We study for the first time the interaction of a single-layer plasma crystal with charged extra particles located above it (upstream of the flow of ions). Upstream extra particles tend to move between the rows of particles in the crystal, accelerate to supersonic speeds, and excite attraction-dominated Mach cones and wakes in the crystal.
Stability and wave dynamics in polytropic Eddington-inspired Born-Infeld gravitating solar plasmas
本文研究EiBI引力对太阳等离子体中波动力学、稳定性及能量传输的影响，发现正χ提升振荡频率和能量通量，负χ增强引力束缚并增加阻尼，通过日震学提供太阳EiBI引力的实证约束。
Lithium Droplet Transport in Tokamak Edge Plasmas
本文提出了一种锂滴输运与蒸发模型，通过直接模拟蒙特卡罗代码OpenEdge验证，展示了输运机制与蒸发过程，并揭示了不同初始条件对边缘等离子体性能的影响。
Solar GES-structure modified with EiBI gravity
本文提出 EiBI 引力修正下的太阳 GES 等离子体平衡模型，发现太阳表面边界外移 14.28%，并改变相关势、场与 Mach 数。
扫码添加微信好友，提出您的宝贵建议 👇
💡 备注请填写：网站反馈
发表机构由 AI 从论文文本抽取，如发现错误，欢迎反馈修正建议。