NONEQUILIBRIUM IN THERMAL PLASMAS WITH APPLICATIONS TO DIAMOND SYNTHESIS

Atmospheric pressure plasmas are frequently considered to be in local thermodynamic equilibrium due to the high frequency of collisional pro cesses which drive the plasma state towards a Maxwell-Boltzmann equili brium. However, various forms of thermodynamic, ionizational, and chem ical nonequilibrium have been demonstrated and investigated in atmosph eric pressure plasma environments over the last several years, and the nonequilibrium behavior of such systems can be quite significant. The investigation, understanding, and exploitation of atmospheric pressur e nonequilibrium plasma chemistry is necessary to the further expansio n of plasma-based systems into mainstream manufacturing and processing applications. Several experimental programs to investigate the fundam ental processes of atmospheric pressure nonequilibrium plasma chemistr y, and the application of this nonequilibrium to various chemical syst ems have been undertaken in our laboratories. The results of these inv estigations have shed light on the kinetics behind various forms of at mospheric pressure nonequilibrium chemistry, and provided insights int o the beneficial control of nonequilibrium plasma chemistry for proces sing applications.