Kinetic Theory of waves in space and astrophysical plasmas

空间波和天体物理等离子体的动力学理论

• 批准号: ST/G002398/1
• 负责人: Michael Balikhin
• 金额: $ 37.43万
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FG002398%2F1
• 关键词: Kinetic; Theory; waves; space; astrophysical

The main goal of the present proposal is to extend the theoretical achievements gained during realization of the existing PPARC grant (PP/D002087/1) to a wider class of physical problems related to the development of a fully kinetic theory of magnetic field generation in space plasmas. This theory may then be applied to interpret observations in such key regions of intergalactic environment as active galactic nucleus (AGNs), microquasars,gamma-ray bursts (GRBs), giant flares and pulsar wind nebulae. Motivations for such a theoretical study result from in-situ satellite observations,importance of a link between processes in solar-terrestrial and astrophysical plasmas, evidence for the plasma mediation by Weibel-type instabilities during shock propagation from astrophysical sources and contribution to fundamental plasma physics. Collisionless plasmas with anisotropic velocity distributions drive a wide class of instabilities such as ion-cyclotron instability, magnetic mirror instability, whistler and Weibel instabilities, thereby generating magnetic fields. The Weibel instability present in homogeneous or nearly-homogeneous plasmas which possess an anisotropy in momentum (velocity) space. In the linear limit the instability causes exponential growth of electromagnetic fields in the plasma which restore momentum space isotropy. In the limit of an extremely anisotropic distribution the Weibel instability is related to one or two-dimensional stream instabilities. In this situation, the Weibel instability is beam-driven, and is sometimes referred to as the filamentation instability. Recently, this instability has attracted considerable attention for both astrophysical and laboratory plasmas. For example, it is considered that this instability can be driven in strong collisionless shock waves associated with various astrophysical phenomena, e.g., pulsar winds, gamma-ray bursts, and/or theirafterglows or gravitational collapse of large-scale structures in the universe. It can also be driven if temperature gradients are present in plasmas. The magnetic field generated by the instability is responsible for synchrotron and or 'jitter' radiation from the existing high-energy particles. Furthermore, such magnetic fields can provide an effective scattering mechanism for charged particles. For example, it would affect the dissipation process of collisionless shock waves and efficiency of the Fermi acceleration or heat conductivity by charged particles. In all these cases, the amplitude of the magnetic field is of primary importance. The main goal of the project is to develop a kinetic theory of waves in space plasmas, incorporating all these features. The present proposal assumes the productive use of the experience gained and results obtained under PPARC grant PP/D002087/1. The main objectives of the project are: To perform a theoretical investigation of the various Weibel type wave modes that exist in space plasmas (dispersion relations, growth rates,instability thresholds etc.) including finite collisionless skin depth,effects due to non-Maxwellian (waterbag and kappa velocity distributions etc.) electron and ion velocity distributions etc. To study the effects of stabilization of the Weibel instability due the final value of the external magnetic field. To provide an analytical and numerical analysis of the nonlinear evolution of Weibel type instabilities in two different cases of weak and strong drive. To elucidate the role of trapped particles in the nonlinear saturation of the instability To apply the developed theory to the physics of remote astrophysical objects. Special attention will be paid to the particle acceleration in space and astrophysical objects.

本提案的主要目的是将现有PPARC赠款（PP/D002087/1）实现期间所获得的理论成就扩展到与与太空等离子体中磁场产生完全动力学理论相关的更广泛的物理问题。然后，该理论可以应用于在这类白平时间环境的关键区域中的观察结果，例如活性银河核（AGN），微Quasar，伽马射线爆发（GRBS），巨型耀斑和脉冲星云。这种理论研究的动机是由原位卫星观察结果，太阳 - 物理和天体物理等离子体中的过程之间联系的重要性，在天体物理学来源引起的电动型繁殖过程中，在天体物理源中引起的等离子体型不稳定性的证据以及对基础血浆物理学的贡献。具有各向异性速度分布的无碰撞等离子体驱动了一类不稳定性，例如离子 - 循环不稳定性，磁性镜像不稳定性，惠斯勒和韦贝尔的不稳定性，从而产生磁场。在均匀或几乎同质的等离子体中存在的菌不稳定性，在动量（速度）空间中具有各向异性。在线性限制中，不稳定性会导致等离子体中电磁场的指数生长，从而恢复了各向同性动量空间。在极端各向异性分布的极限下，魏伯的不稳定性与一维流不稳定性有关。在这种情况下，微生的不稳定性是梁驱动的，有时被称为细丝不稳定性。最近，这种不稳定引起了对天体物理和实验室等离子体的极大关注。例如，认为这种不稳定性可以以与各种天体物理现象相关的强无碰撞冲击波驱动，例如，脉冲星，脉冲风，伽马射线爆发和/或它们的效果或反性或重力崩溃的宇宙中大型结构。如果等离子体中存在温度梯度，也可以驱动它。不稳定性产生的磁场负责从现有的高能量颗粒中的同步加速器和 /或“抖动”辐射。此外，这样的磁场可以为带电颗粒提供有效的散射机制。例如，这将影响无碰撞冲击波的耗散过程以及带电颗粒的费米加速度或热导率的效率。在所有这些情况下，磁场的幅度都是重要的。该项目的主要目的是在空间等离子体中发展一个波动的动力学理论，并结合了所有这些功能。本提案假定获得的经验的生产性使用，并根据PPARC赠款PP/D002087/1获得的结果。该项目的主要目标是：对空间等离子体中存在的各种芯片类型波模式进行理论研究（分散关系，增长率，生长速率，不稳定性阈值等），包括有限的无碰撞皮肤深度，非Maxwellian引起的效果，这是由于waterbag and Kappa速度分布等的效果等于启用的启用，以使电子和离子速度的效果效果效果。外部磁场。在两种不同的弱驱动器和强驱动器的情况下，提供了对微生型不稳定性的非线性演化的分析和数值分析。为了阐明被困颗粒在不稳定性的非线性饱和度中的作用，将开发理论应用于远程天体物理对象的物理学。将特别注意空间和天体物理物体中的粒子加速度。

项目成果

Relativistic filamentary equilibria

相对论丝状平衡

• DOI: 10.1017/s002237781000005x
• 发表时间: 2010
• 期刊: Journal of Plasma Physics
• 影响因子: 2.5
• 作者: GEDALIN M

The theory of magnetic hole formation in the vicinity of the Earth's magnetoshere

地球磁层附近磁洞形成理论

• DOI: 10.1134/s1028334x09060233
• 发表时间: 2009
• 期刊: Doklady Earth Sciences
• 影响因子: 0.9
• 作者: Istomin Y

Growth of filaments and saturation of the filamentation instability

• DOI: 10.1063/1.3345824
• 发表时间: 2010-03
• 期刊: Physics of Plasmas
• 影响因子: 2.2
• 作者: M. Gedalin;M. Medvedev;M. Medvedev;M. Medvedev;A. Spitkovsky;V. Krasnoselskikh;M. Balikhin;A. Vaivads;S. Perri

Quasi-linear dynamics of Weibel instability

Weibel 不稳定性的拟线性动力学

• DOI: 10.5194/angeo-29-1997-2011
• 发表时间: 2011
• 期刊: Annales Geophysicae
• 影响因子: 1.9
• 作者: Pokhotelov O

Nonlinear waves and shocks in relativistic two-fluid hydrodynamics

相对论二流体流体动力学中的非线性波和冲击

• DOI: 10.1017/s002237781200013x
• 发表时间: 2012
• 期刊: Journal of Plasma Physics
• 影响因子: 2.5
• 作者: HAIM L