Collaborative Research: Effects of the Magnetic Field Shear and Flow Shear on Kinetic Physics in Relativistic Magnetic Reconnection

合作研究：磁场剪切和流剪切对相对论磁重联运动物理的影响

• 批准号: 1902867
• 负责人: Yi-Hsin Liu
• 金额: $ 52.5万
• 依托单位: Dartmouth College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1902867&HistoricalAwards=false
• 关键词: Collaborative; Research; Effects; Magnetic; Field

Magnetic reconnection is a fundamental plasma process, where a change in the connectivity of magnetic field lines rapidly converts energy of the magnetic field into acceleration of charged particles in the plasma. This project aims to improve our understanding of relativistic magnetic reconnection in astrophysical systems. Prompted by the observation of superflares in the Crab Nebula, over the past five years there has been a surge of interests in relativistic reconnection in the high-energy astrophysics community. However, the rich physics of high energy magnetic reconnection and its associated particle acceleration remain less studied compared to their non-relativistic counterparts in Earth's magnetosphere and solar wind. This project will serve to cross-fertilize understanding of magnetic reconnection between the heliophysics and astrophysics communities, which in turn will help develop new insights into this fundamental process and its potential applications. The research activity will include training of students and a postdoc at Dartmouth College and a summer student intern through the New Mexico Consortium.In astrophysical systems such as pulsar wind nebulae and relativistic jets associated with gamma-ray bursts and black holes, the magnetic energy density is much greater than the plasma energy density. In such strongly magnetized plasmas, outflow speed from magnetic reconnection events can reach values close to the speed of light with relativistic effects becoming important. In a realistic system, magnetic reconnection is also often accompanied by finite guide fields and flow shear. A guide field can reduce the reconnection outflow speed, while a shear flow can couple reconnection with flow vortices to affect plasma transport and energy dissipation. It is thus imperative to study and identify how special relativity can affect the dynamics of reconnection under these general conditions. To obtain a self-consistent picture of particle acceleration and to resolve the dissipation-scale physics that breaks the magnetic connectivity, the project will employ a state-of-the-art particle-in-cell code VPIC and provide a fully kinetic description of collisionless magnetic reconnection in the relativistic regime. The results of this study will be relevant for many astrophysical sources and will address the goals of NSF's "Windows on the Universe: The Era of Multi-Messenger Astrophysics" Big Idea. This project is jointly supported by the Division of Physics and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

磁重新连接是一个基本的等离子体过程，其中磁场线的连通性的变化迅速将磁场的能量转化为等离子体中带电颗粒的加速度。 该项目旨在提高我们对天体物理系统中相对论磁重新连接的理解。 在螃蟹星云中观察到的超级流域的提示，在过去的五年中，对高能天体物理学社区的相对论重新连接引起了人们的兴趣。然而，与地球磁层和太阳风中的非相对论对应物相比，高能磁重新连接及其相关颗粒加速度的丰富物理学的研究量保持较少。 该项目将有助于交叉利用对热物理学和天体物理学群落之间的磁重新连接的理解，这反过来又将有助于发展对这一基本过程及其潜在应用的新见解。 研究活动将包括对学生的培训和达特茅斯学院的博士后培训以及通过新墨西哥联盟的夏季学生实习生。远大于血浆能量密度。在如此强烈的磁化等离子体中，磁重新连接事件的流出速度可以达到接近光速的值，相对论效应变得很重要。在现实的系统中，磁重新连接通常还伴随有限的导向场和流剪切。导向场可以降低重新连接的流出速度，而剪切流可以将重新连接与流量涡流相结合，以影响等离子体的传输和耗能。因此，必须研究和确定在这些一般条件下重新连接的动力学的特殊相对论如何影响。为了获得粒子加速度的自洽图像并解决破坏磁连通性的耗散尺度物理学，该项目将采用最新的粒子粒子代码VPIC，并提供对的完全动力学描述相对论方案中无碰撞的磁重新连接。 这项研究的结果将与许多天体物理学来源相关，并将解决NSF“宇宙窗口：多理智的天体物理学时代”的目标。该项目得到了物理学和启发竞争研究的既定计划（EPSCOR）的共同支持。该奖项反映了NSF的法定任务，并且使用基金会的知识分子优点和更广泛的影响评估标准，被认为值得通过评估来提供支持。

项目成果

Diffusive Plasma Transport by the Magnetopause Kelvin-Helmholtz Instability During Southward IMF

• DOI: 10.3389/fspas.2021.809045
• 发表时间: 2022-01
• 作者: T. Nakamura;K. Blasl;Y. Liu;S. Peery

Fast magnetic reconnection induced by resistivity gradients in 2D magnetohydrodynamics

• DOI: 10.1063/5.0052317
• 发表时间: 2021-07
• 期刊: Physics of Plasmas
• 影响因子: 2.2
• 作者: Shan-Chang Lin;Yi‐Hsin Liu;Xiaocan Li

Multi-scale evolution of Kelvin?Helmholtz waves at the Earth's magnetopause during southward IMF periods

IMF南移期间地球磁层顶开尔文·亥姆霍兹波的多尺度演化

• DOI: 10.1063/5.0067391
• 发表时间: 2022
• 期刊: Physics of Plasmas
• 影响因子: 2.2
• 作者: Nakamura T. K. M.;Blasl K. A.;Hasegawa H.;Umeda T.;Liu Y.-H.;Peery S. A.;Plaschke F.;Nakamura R.;Holmes J. C.;Stawarz J. E.;Nystrom W. D.
• 通讯作者: Nystrom W. D.

The relation between the energy conversion rate and reconnection rate in Petschek-type reconnection—Implications for solar flares

Petschek型重联中能量转换率与重联率之间的关系——对太阳耀斑的启示

• DOI: 10.1063/5.0050557
• 发表时间: 2021
• 期刊: Physics of Plasmas
• 影响因子: 2.2
• 作者: Goodbred, Matthew;Liu, Yi-Hsin;Chen, Bin;Li, Xiaocan
• 通讯作者: Li, Xiaocan

Exploring the Acceleration Mechanisms for Particle Injection and Power-law Formation during Transrelativistic Magnetic Reconnection

• DOI: 10.3847/1538-4357/aba1e9
• 发表时间: 2020-01
• 期刊: The Astrophysical Journal
• 作者: P. Kilian;Xiaocan Li;F. Guo;Hui Li