Pulsed plasma microjets: A new tool for plasma kinetics and molecular spectroscopy

Summary form only given. The recent development of microcavity plasma devices fabricated in an Al/Al₂O₃ system has resulted in robust, chemically inert devices exhibiting relatively low breakdown voltages at near-atmospheric pressures. Due to their small size and near-atmospheric operating pressure, these and similar microcavity devices have been shown to produce metastable molecules, such as Xe₂* and XeO*. Additionally, microjets having diameters as small as 300 μm have been demonstrated in Al/Al₂O₃ structures. These plasma devices enable the generation of transient molecules and radicals requiring an atmospheric pressure plasma environment. In this work, we investigate an Al/Al₂O₃ microjet combined with a pulsed gas system as a means of generating highly excited and/or metastable molecules at background pressures in excess of one atmosphere. Upon creation, these molecules are subsequently ejected into a vacuum environment, where they cool via supersonic expansion and are available for study in a setting that offers a greatly reduced degree of collisionality. Thus we are able to report a new tool for the study of not only metastable molecules, but of plasma kinetics in general. Recent results of experiments probing dissociative recombination of Ne₂⁺ and Ar₂⁺ will be described.