Application of Non-Local Effects to Lasers and Plasma Chemistry in Flowing-Gas and Pulsed Electric Discharges.

Oxygen and/or air plasmas are widely used in different processes such as etching, purifying, ashing, surface cleaning, ozone generation and for electrical oxygen/iodine laser discharges. The oxygen plasma is an important example of electronegative plasmas and has been widely studied and modeled, including non-local effects due to discharge boundaries, low pressure or unsteady-state or afterglow operation. The proposed Phase I program will investigate the so far neglected effect of the relatively high energy electrons created by associative detachment of negative ions. For some conditions, these electrons can form a major portion of the electron population and causing additional non-local effects. The contribution to the electron energy distribution by the detached electrons will be investigated, and the model will include these additional non-local effects. Appropriate modeling approaches will be considered for pulsed and flowing gas plasmas. Beneficial effects or controls using the non-local effects will be investigated. In a following Phase II program, further refinements of the model will be performed and example technical plasmas will be tested experimentally. The oxygen plasma is widely used and a more accurate model and possible improvements due to better understanding of the plasma kinetics will be important for both commercial and military applications.