Collaborative Research: Turbulence, Structures, and Diffusive Shock Acceleration

合作研究：湍流、结构和扩散冲击加速

• 批准号: 1707247
• 负责人: Gary Zank
• 金额: $ 30万
• 依托单位: University of Alabama in Huntsville
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1707247&HistoricalAwards=false
• 关键词: Collaborative; Research; Turbulence; Structures; Diffusive

This project will further our understanding of the origin and properties of highly energetic particles accelerated at shock waves in outer space. Shock waves in the interplanetary and interstellar medium are known to accelerate charged particles to very high (relativistic) energies. Exactly how this is done remains an important open problem. Energized particles irradiate the Earth, satellites and astronauts orbiting the Earth, and spacecraft exploring the heliosphere and other planets. Highly energetic particles represent a hazard to biological systems and technological systems, including communication, positioning, and observational and research satellites. Thus, determining the origin and subsequent properties of very energetic charged particles can have important technological and biological consequences that impact our daily lives and even the national security of the US. This award will support a collaborative effort between the University of Alabama - Huntsville and the New Mexico Consortium, with support from the Department of Energy, to investigate the effects of complex plasma structures that are typically generated at shock waves on the production of highly energetic particles in interplanetary space. This project will, for the first time, develop quantitative and testable models of particle energization in shock generated turbulence, which is in turn dissipated via reconnection current layers, associated magnetic plasmoids, and particle energization. The coupling of diffusive shock acceleration (DSA) and particle acceleration in the turbulent wake of fast shocks cleaves naturally into two: A) the generation, transmission, and amplification of turbulence and structures at collisionless shock waves, and B) the coupled acceleration of electrons and ions at and in the turbulent wake of collisionless shocks. This project will 1) develop models, validated by simulations that describe the transmission and generation of turbulence through and at collisionless quasi-perpendicular and quasi-parallel shock waves; 2) determine whether collisionless shocks can generate magnetic structures downstream of the shock and will describe the downstream evolution of shock-generated structures through reconnection-related processes; 3) explain the interaction of magnetic structures and current sheets, including the heliospheric current sheet, with incident shock waves; and 4) use numerical models and observations of turbulence, magnetic structures, and current sheets interacting with shocks to develop a theory of particle acceleration in the vicinity of shock waves.

该项目将进一步理解在外层空间的冲击波中加速高能粒子的起源和特性。 已知星际和星际培养基中的冲击波将带电的颗粒加速至非常高（相对论）的能量。确切的做法仍然是一个重要的开放问题。充满活力的颗粒照射地球，卫星和宇航员绕地球，并探索天气圈和其他行星的航天器。高能量的颗粒代表了对生物系统和技术系统的危害，包括通信，定位以及观察和研究卫星。因此，确定非常有活力的充电颗粒的起源和后续特性可能会产生重要的技术和生物学后果，从而影响我们的日常生活，甚至影响美国的国家安全。 该奖项将支持阿拉巴马大学 - 亨茨维尔大学和新墨西哥联盟之间的合作努力，并在能源部的支持下，研究通常在冲击波上产生的复杂等离子体结构对产量在跨界空间中产生的高能颗粒的影响。该项目将首次在冲击产生的湍流中开发粒子能量的定量和可测试模型，而湍流又通过重新连接电流层，相关的磁性浆液和粒子能量消散。在快速冲击的湍流唤醒中，扩散冲击加速度（DSA）和颗粒加速度的耦合自然地裂解为两个：a）在无碰撞冲击波上的湍流和结构的发射，传播和扩增，以及b）无碰撞电击的电子和离子的耦合。该项目将1）开发模型，并通过描述无碰撞的准垂直和准平行冲击波的湍流的传播和产生的模拟验证； 2）确定无碰撞冲击是否可以产生冲击下游的磁性结构，并将通过重新连接相关的过程来描述电击生成结构的下游演变； 3）解释磁性结构和电流板的相互作用，包括气层电流板，并与入射冲击波相互作用； 4）使用数值模型以及湍流，磁性结构和与冲击相互作用的电流板的观察，以在冲击波附近发展粒子加速度理论。

项目成果

A possible explanation for the enhancement of energetic particles downstream of the heliospheric termination shock

• DOI: 10.1088/1742-6596/1332/1/012020
• 发表时间: 2019-11
• 期刊: Journal of Physics: Conference Series
• 作者: L. L. Zhao-L.;G. Zank;L. Adhikari

Radial evolution of the properties of small-scale magnetic flux ropes in the solar wind

• DOI: 10.1088/1742-6596/1332/1/012005
• 发表时间: 2019-11
• 期刊: Journal of Physics: Conference Series
• 作者: Q. Hu;Yu Chen;J. A. Roux

Modeling Energetic Particle Acceleration and Transport in a Solar Wind Region with Contracting and Reconnecting Small-scale Flux Ropes at Earth Orbit

• DOI: 10.3847/1538-4357/ab521f
• 发表时间: 2019-12
• 期刊: The Astrophysical Journal
• 作者: J. L. le Roux;G. Webb;O. Khabarova;L.-L. Zhao-L.;L. Adhikari

An introductory guide to fluid models with anisotropic temperatures. Part 1. CGL description and collisionless fluid hierarchy

• DOI: 10.1017/s0022377819000801
• 发表时间: 2019-01
• 期刊: Journal of Plasma Physics
• 影响因子: 2.5
• 作者: P. Hunana;P. Hunana;A. Tenerani;G. Zank;E. Khomenko;E. Khomenko;M. Goldstein;G. Webb;P. Cally;M. Collados;M. Collados;M. Velli;L. Adhikari

Energy dissipation and entropy in collisionless plasma

• DOI: 10.1103/physreve.101.033208
• 发表时间: 2020-03-24
• 期刊: PHYSICAL REVIEW E
• 影响因子: 2.4
• 作者: Du, Senbei;Zank, Gary P.;Guo, Fan
• 通讯作者: Guo, Fan