RUI: Experimtental Study of the Thermal State of Weakly-Coupled Dusty Plasmas and Nonlinear Properties of the Dust Acoustic Wave

Wittenberg University, Springfield OH

Investigators

Abstract

The award will support a series of experiments aimed at understanding fundamental properties of a unique state of matter, a "dusty" or "complex" plasma, which is an ionized gas consisting of ions, electrons, and small particulate matter (dust or ice) that is typically much smaller than the width of a human hair. In space, examples of dusty plasmas include the clouds from which stars and planets form, comet tails, planetary rings and noctilucent clouds in the Earth's ionosphere. Dusty plasmas are also formed in the chemically active plasmas that are used in industrial plasma processing devices to create computer chips, contaminating the end product and reducing overall yield, and the manufacturing of solar photovoltaic cells, where the dust can increase the overall efficiency of the resulting solar cells. The research program will support the training of several highly talented undergraduate students in a small college environment, providing the students with a more comprehensive research skills training than at comparable experiences at larger institutions; experience with state-of-the-art software and experimental techniques; and a variety of practical problem solving skills. The research program consists of several experiments designed to understand the thermal and transport properties of weakly-coupled (fluid-like) dusty plasmas. One series of experiments is designed to measure the thermal state of weakly-coupled dusty plasmas to better understand the mechanism responsible for the high temperatures that have been measured in a number of experimental systems. This effort will directly test two models that are believed to be responsible for the observed heating and will also support the development of a time-resolved stereoscopic particle image velocimetry (PIV) system. This work will extend collaborative work done in the development of a time-resolved planar PIV with colleagues at in the Plasma Science Laboratory at Auburn University and the Complex Plasmas Research Group at the German Aerospace Center. Additionally, a portion of this work will be done at the newly operational Magnetized Dusty Plasma Experiment facility at Auburn University and will examine the effect that magnetic fields have on the thermal state of these dusty plasma systems. A second series of experiments is designed to understand the properties of a fundamental wave mode that propagates in dusty plasma systems known as the dust acoustic wave. The contribution that thermal effects have on how this wave propagates and the nonlinear process of synchronization where the properties of the wave adjust to match an externally applied drive will be investigated. Together, these studies will contribute to the fundamental understanding of the thermal properties of dusty plasmas and provide new insight into the nonlinear properties of the dust acoustic wave.