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

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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.