Collaborative Research: Non-linear Physics of the Interaction Between a Relativistic Electron Beam and Magnetized Plasma: An Integrated Experimental and Modeling Approach

该项目采用实验室实验和计算机模拟相结合的方法，研究以接近光速的速度移动的电子束如何与空间等离子体相互作用。这既是一个基本问题，也是一个实际问题，与空间物理学和天体物理学中许多具有挑战性的问题有关。 例如，众所周知，空间中的高能粒子对通信卫星构成危险;有人提出，可利用未来航天器上直接产生的电子束产生的波，将这种高能粒子从近地空间区域清除。这项工作将详细研究电子束可以产生的波的类型，以及这些束如何通过空间等离子体传播。除了为未来的空间实验提供科学基础外，该合作项目还将为明尼苏达大学的本科生和研究生提供实验室等离子体技术方面的培训。该项目旨在为理解和预测相对论性（能量在0.1-1 MeV范围内）、有限尺寸、调制束和磁化等离子体。大多数早期的调查集中在低能量光束，不能提供显着的权力，周围的等离子体发射时，从航天器在低密度磁层等离子体中运行，由于航天器充电效应。相对较少的是已知的可能性，激发感兴趣的等离子体波（如哨声）与兆电子伏的光束。该项目将结合联合收割机理论，二维和三维动力学模拟，并在基础等离子体科学设施，位于加州大学洛杉矶分校的用户设施，并由NSF和能源部联合支持的大型等离子体设备上进行的实验室实验。这些实验将利用洛斯阿拉莫斯国家实验室最近开发的独特可变能量电子束源，该源将允许进行前所未有的电子束参数扫描。

This project uses a combination of laboratory experiments and computer simulations to study how electron beams moving with speeds approaching the speed of light interact with space plasmas. This is both a fundamental and practical problem that is relevant to many challenging issues in space physics and astrophysics. For example, it is well known that energetic particles in space pose a danger to communication satellites; and it has been proposed that such energetic particles could be removed from near-Earth regions of space by waves generated via electron beams produced directly on future spacecraft. This work will investigate in detail the types of waves that can be produced by electron beams and how such beams propagate through space plasmas. In addition to providing the scientific basis for future space-borne experiments, this collaborative project will also provide training in laboratory plasma techniques for undergraduate and graduate students at the University of Minnesota.The project aims to provide an experimentally validated theoretical framework for understanding and predicting the coupling between a relativistic (with energies in the range of 0.1-1 MeV), finite size, modulated beam and magnetized plasmas. Most earlier investigations have focused on low energy beams that cannot deliver significant power to the surrounding plasma when emitted from a spacecraft operating in a low-density magnetospheric plasma due to spacecraft charging effects. Comparatively little is known about possibility of exciting plasma waves of interest (e.g. whistler) with MeV beams. The project will combine theory, two-dimensional, and three-dimensional kinetic simulations, and laboratory experiments performed on the Large Plasma Device at the Basic Plasma Science Facility, a user facility located at UCLA and jointly supported by NSF and DOE. These experiments will utilize a unique variable-energy electron beam source recently developed at the Los Alamos National Laboratory that will allow for an unprecedented electron beam parameter scan.