Nonlinear Dynamics of Strong Interchange Instabilities in a Rotating Dipole Plasma

Columbia University, New York NY

Investigators

Abstract

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 partially support the graduate student participation in the overall research effort, which is being funded separately by the DoE [Grant DE-FG02-00ER54585OFES]. The nonlinear dynamics of strong interchange instabilities concern fundamental phenomenon occurring in a variety of natural and artificial situations. In this work, laboratory techniques will be used to produce intense interchange instabilities, induce strong interchange convection, and sustain steady interchange turbulence. The investigations focus on measurement, modification, and understanding of strong interchange turbulence. Previous work has found that interchange turbulence is dominated by large-scale rotating structures, and, probably, these structures represent a "self-organized" state. With this award, remaining questions concerning the precise nature of structure coupling and transport will be addressed with improved diagnostics, additional probes, and advanced simulations using our newly parallelized nonlinear interchange code. The combination of detailed experimental measurements, computer simulation, and computer data analysis will test developing theory and provide a basis for understanding a variety of nonlinear processes which occur in plasmas produced in the laboratory and found in nature. The Collisionless Terrella Experiment (CTX) research project creates connections between laboratory plasma physics, natural plasma phenomena, nonlinear physics, and computational physics. CTX serves a central and important role in the educational opportunities for Columbia University graduate and undergraduate students. Undergraduate student research interns assembled the CTX device, and this project will continue to be a student-focused research program. This project attracts outstanding graduate and undergraduate students and has provided hands-on research experience to talented high school students. This NSF award provides support for the Graduate Research Assistant involved with this research project.