Time Domain Structures Driven by Whistler and Kinetic Alfven Waves in a Laboratory Plasma

实验室等离子体中惠斯勒波和动能阿尔文波驱动的时域结构

• 批准号: 2108582
• 负责人: Xin An
• 金额: $ 53.42万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-15 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2108582&HistoricalAwards=false
• 关键词: Time; Domain; Structures; Driven; Whistler

Observations of the Earth’s outer radiation belts uncovered intense electric field spikes called “time domain structures” (TDSs). They occur in plasma boundaries, where the energetics and dynamics are poorly understood. This project will use laboratory experiments, simulations, and analysis of satellite data to understand the plasma physics resulting in TDSs. This is an important process to understand how particles gain and lose energy within the radiation belts with applications towards space weather impacts, such as creation of detrimental effects to satellite operations. The project supports two early career scientists, a graduate student, and undergraduate students. The project will test the hypothesis that TDSs are excited by secondary electron beams trapped in the parallel electric fields of kinetic Alfven waves and whistler waves. Experiments will be conducted with the UCLA Large Plasma Device (LAPD) to generate TDSs by launching a large amplitude whistler or kinetic Alfven wave into a plasma. The laboratory data will be used in conjunction with data from particle-in-cell simulations. Field and particle measurements from NASA satellites will be compared to the laboratory and simulation results. The following science questions will be addressed: (1) What plasma parameters determine the type of TDS that will be generated? (2) What are the characteristics of TDSs? (3) How does the amplitude of whistler waves and kinetic Alfven waves affect the excitation of TDSs?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.

对地球外部辐射带的观测发现了被称为“时域结构”（TDS）的强烈电场尖峰。它们发生在等离子体边界，那里的能量学和动力学知之甚少。该项目将使用实验室实验、模拟和卫星数据分析来理解导致TDS的等离子体物理。这是了解粒子如何在辐射带内获得和损失能量的一个重要过程，可应用于空间气象影响，例如对卫星运行产生有害影响。该项目支持两名早期职业科学家，一名研究生和一名本科生。该项目将检验这样一种假设，即TDS是被捕获在动力学阿尔芬波和哨声波的平行电场中的二次电子束激发的。实验将进行与加州大学洛杉矶分校的大型等离子体装置（LAPD），以产生TDS发射到等离子体的大振幅哨声或动力阿尔芬波。实验室数据将与粒子模拟数据结合使用。来自NASA卫星的场和粒子测量结果将与实验室和模拟结果进行比较。将解决以下科学问题：（1）哪些血浆参数决定将产生的TDS类型？(2)TDS有哪些特点？(3)哨声波和动力学阿尔芬波的振幅如何影响TDS的激发？该奖项反映了NSF的法定使命，并被认为是值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估的支持。

项目成果

Auroral Beads in Conjunction With Kinetic Alfvén Waves in the Equatorial Inner‐Magnetosphere

极光珠与赤道内磁层中的动能阿尔文波相结合

• DOI: 10.1029/2022gl098457
• 发表时间: 2022
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Tian, S.;Lyons, L. R.;Nishimura, Y.;Wygant, J. R.;Lysak, R. L.;Ferradas, C. P.;An, X.;Igl, A. B.;Reeves, G. D.;Larsen, B. A.
• 通讯作者: Larsen, B. A.

Fast Inverse Transform Sampling of Non-Gaussian Distribution Functions in Space Plasmas

空间等离子体中非高斯分布函数的快速逆变换采样

• DOI: 10.1029/2021ja030031
• 发表时间: 2022
• 期刊: Journal of geophysical research
• 作者: An, Xin;Artemyev;Angelopoulos, Vassilis;Lu, San;Pritchett, Philip;Decyk, Viktor
• 通讯作者: Decyk, Viktor

Nonlinear Landau Resonant Interaction Between Kinetic Alfvén Waves and Thermal Electrons: Excitation of Time Domain Structures

动态阿尔文波与热电子之间的非线性朗道共振相互作用：时域结构的激发

• DOI: 10.1029/2020ja028643
• 发表时间: 2021
• 期刊: Journal of Geophysical Research: Space Physics
• 作者: An, Xin;Bortnik, Jacob;Zhang, Xiao‐Jia
• 通讯作者: Zhang, Xiao‐Jia