Nonlinear Wave-particle Interactions

非线性波粒相互作用

• 批准号: 0903802
• 负责人: Jacob Bortnik
• 金额: $ 68.47万
• 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: 2009
• 资助国家: 美国
• 起止时间: 2009-07-15 至 2013-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0903802&HistoricalAwards=false
• 关键词: Nonlinear; Wave; particle; Interactions

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The project is being funded jointly by the Division of Atmospheric Sciences of the Geosciences Directorate and by the Division of Physics in the Mathematical and Physical Sciences Directorate.This project will study nonlinear wave-particle interactions between relativistic electrons and whistler mode waves with a combination of theory/numerical simulation and experiment via the Large Plasma Device (LAPD) at UCLA. The motivation is to understand the dynamics of Earth's radiation belts, which is a critical unresolved problem in magnetospheric physics. There is a dichotomy between the two methods used to model wave-particle interactions: namely quasilinear diffusion theory and the test-particle simulations. The quasilinear theory breaks down in the outer radiation belt where large amplitude, narrow-band coherent waves have recently been observed. The porject will extend a recent test particle approach using a distribution of electrons and wave amplitudes and phases in order to derive a more self-consistent treatment of the interaction of energetic electrons with large amplitude coherent whistler waves. Experiments will be carried out on the LAPD involving the interaction of an energetic electron beam propagating from one end of the device with waves launched from the other end. The change in the pitch-angle and energy of the beam will be measured. The experimental results will compared to the theoretical/numerical simulations to improve and validate the theory.The project is headed by a young research scientist and will also involve a postdoctoral researcher and a graduate student. The project has societal impacts related to space weather.

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。该项目由地球科学理事会大气科学司和数学和物理科学理事会物理司共同资助。本项目将通过加州大学洛杉矶分校的大型等离子体装置（LAPD），以理论/数值模拟和实验相结合的方式，研究相对论电子与哨声模波之间的非线性波粒相互作用。其动机是了解地球辐射带的动力学，这是磁层物理学中一个关键的未解决的问题。在模拟波粒相互作用的两种方法之间存在着二分法：即准线性扩散理论和测试粒子模拟。拟线性理论在最近观测到的大振幅窄带相干波的外辐射带失效。该项目将扩展最近的一种测试粒子方法，使用电子和波振幅和相位的分布，以便对高能电子与大振幅相干哨声波的相互作用进行更自一致的处理。实验将在LAPD上进行，涉及从设备一端传播的高能电子束与从另一端发射的波的相互作用。将测量光束的俯仰角和能量的变化。实验结果将与理论/数值模拟进行比较，以改进和验证理论。该项目由一名年轻的研究科学家领导，还将有一名博士后研究员和一名研究生参与。该项目具有与太空天气有关的社会影响。