Spatially and Temporally Resolved Electric Fields in a Plasma Sheath

Summary form only given. We employ laser-induced dip-fluorescence to detect Stark shifts in atomic argon Rydberg states induced by electric fields present in the plasma sheath. The Stark shifts of these Rydberg states are calibrated for a set of known electric fields. The choice of probed Rydberg state determines the electric field range and resolution we can achieve. Both spatially and temporally resolved maps of the electric fields are obtained above powered electrodes generating the plasma. Configurations studied include a metal-dielectric electrode, a stepped electrode, and an electrode composed of dissimilar metals. The structure of the sheath, as well as the structure of the discharge, is observed to be functions of the powered electrode's configuration. Possible mechanisms responsible for the observed electrode dependencies are discussed