Fundamental Processes In Plasmas

University Of California-San Diego, La Jolla CA

Investigators

Abstract

This award supports a program of theory and experiments to develop detailed understanding of waves and particle confinement in a plasma -- a gas of freely interacting electrically charged particles -- placed in a magnetic trap. The studies will characterize wave damping caused by individual particles bouncing end-to-end in the trap at different frequencies. The plasma transport and loss caused by internal magnetic irregularities will also be analyzed and measured. This research program has broad connections to fluid physics, atomic physics, anti-matter production, and fusion plasmas for power generation, and provides a stimulating environment for graduate and undergraduate student education. Experiments will be performed on two non-neutral plasma devices: the camera-diagnosed electron plasma apparatus "CamV" and on the laser-diagnosed Magnesium ion plasma apparatus "IV". Analytical theory and medium-scale simulation results will be directly compared to the experiments over a broad range of parameters. The goal is to identify limitations in the theory, and to stimulate new theory where needed. In particular, this research will elucidate the effects of internal potential variations, as bounce-harmonic Landau damping depends sensitively on the particle trajectories. Further, magnetic irregularities leading to topological separatrices are endemic to both quasi-neutral and non-neutral plasmas, and the novel "chaotic superbanana" transport to be studied here occurs even in nearly collisionless plasmas. This award to support an undergraduate student is made under the NSF/DOE Partnership in Basic Plasma Science and Engineering and is complementary to a DOE award made under the joint program.