Axial Plasma Jets and their Interaction with and Production of Alfvén Waves

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This award is made in response to a proposal submitted to and reviewed under the NSF/DoE Partnership in Basic Plasma Science and Engineering joint solicitation NSF 08-589. The award provides funds to support travel for a graduate student to scientific conferences and for undergraduate participation in the overall research effort, which is being funded separately by the DoE under contract to UCLA (Science report #09ER55061)This research will use UCLA's unique LAPD facility and its laser plasma capability to do experiments on the coupling of mass, energy, and momentum from a localized, dense, and rapidly expanding plasmas into a large-scale magnetized background plasma. Using the laser we will generate field-aligned plasma flows that can be varied from supersonic to super Alfvénic. The research program is divided into three main topics: 1) the coupling of plasma jets to compressional Alfvén waves, 2) the creation of wakes and structure with supersonic flows, and 3) the interaction of Alfvén waves with fast-flowing plasmas. The experiments will be complemented by computer simulations using a state-of-the-art PIC code developed at UCLA. The code is capable of resolving skin depth structures as well as tracking Alfvénic phenomena. The nonlinear interaction of Alfvén waves with moving plasmas has been the subject of theoretical studies but has never been probed in laboratory experiments. This study is of relevance to phenomena in the Earth's magnetotail, coronal plume expansion within low beta coronal holes, and could be of relevance to astrophysical jets. The NSF support of undergraduate participation adds a broader educational impact through the early-year training of students by introducing them to scientific research as a possible career path.