Ashley Eadon

Design and initial operation of the Auburn Linear Experiment for Instability Studies: A new plasma experiment for studying shear driven flows

The Auburn Linear Experiment for Instability Studies (ALEXIS) is a new plasma physics experiment that is designed to investigate the role of spatially nonuniform E×B drifts using a cylindrical plasma column. This article discusses the design and construction of the ALEXIS device and preliminary measurements of the electric and magnetic field configuration of the device.

Suppression of drift waves in a linear magnetized plasma column

In magnetically confined fusion plasmas, drift wave driven turbulence can lead to enhanced particle transport from the plasma. Because of this, a significant research emphasis has been placed on the suppression of drift waves in the plasma edge. However, the combination of the toroidal geometry and short plasma lifetimes can make it difficult to fully characterize the properties of these instabilities. Because linear magnetized plasma devices offer a combination of simpler geometry and steady state plasma generation, it is possible to perform detailed studies of many types of plasma instabilities—including drift waves. This paper reports on a recent experiment in which low frequency instabilities (ω ≤ ωci) in the Auburn Linear EXperiment for Instability Studies plasma device were characterized as drift waves and through changes in the parallel current, it is shown that it is possible to suppress these instabilities.

Suppression of low frequency plasma instabilities in a magnetized plasma column

This paper reports on a new experimental observation of the suppression of both naturally occurring and driven oscillations in a magnetized, linear plasma column. Detailed measurements are made of the potential structure, density profiles, and wave propagation using Langmuir and emissive probes. These measurements indicate that the decrease in the level of plasma oscillations (by factors of 10 or greater) is related to the direction of the radial electric field, but may also be connected to a combination of transverse and parallel flows in the plasma.