Principal Investigator: Demidov, Vladimir Institution: West Virginia University Research Corporation Proposal No: CBET-0903635
The focus of this research is to investigate the fundamental phenomena which determine the electron energy distribution (EED) in plasmas, with a particular emphasis on partially ionized gases. The critical question posed is to explain why electrons with energy higher than the confining plasma potential persist in collisionless and weakly collisional plasmas (the so-called Langmuir paradox). In a collisionless plasma, the project will (1) provide experimental investigations of the electron energy distribution (EED) in plasmas of low pressure, (2) analyze mechanisms for formation of the nonlocal electron energy distribution on the base of the kinetic equation, (3) provide calculations of the electron energy distribution and their comparison with experiments, and (4) investigate the influence of voltage applied to additional electrodes on plasma kinetics. In a collisional plasma, the project will (1) perform detailed measurements of the EEDs in plasmas with the existence of a small fraction of energetic electrons, such as plasmas in afterglow and short discharges, in the presence of additional charged electrodes, (2) analyze mechanisms of formation of the EEDS for those cases and (3) investigate the influence of voltage applied to discharge boundaries on plasma properties.
The long-range goals are to provide the plasma community with a better understanding of electron kinetics in low pressure collisionless and collisional plasmas and provide a reliable theoretical approach to calculations of electron energy distributions under conditions appropriate to the Langmuir paradox and for higher pressures. The significance of the project is that, historically, a poor understanding of electron kinetics, and the influence of discharge boundaries on the electron energy distribution formation, has resulted in an unsatisfactory description of bounded low-pressure plasmas. This situation has resulted in an inability to achieve real optimization of many industrial plasma processing devices. The research will justify the application of a nonlocal approach for similar plasmas and will allow reliable calculations of electron-energy distributions in those plasmas.
The broader impacts of the proposed work will come from synergy of research and education and training of undergraduate and graduate students. Broad distribution of the results will be performed via journal publications, presentations at national and international conferences. Students will present the results of their work at the annual APS DPP meetings and will participate in journal publications.
