Vacuum ultraviolet emission and metastable state properties of DC microdischarges

Summary form only given, as follows. We report on experimental studies of vacuum ultraviolet emission and excited state populations in high-pressure microdischarges intended to simulate the operation of a single pixel in a flat plasma display panel. In PDP cells, ultraviolet light produced by the He/Xe plasma controls the color purity and brightness of red, green or blue pixels. In the results reported, our microdischarge consists of two bare coaxial brass electrodes separated by a few hundreds of micrometers, across which a DC voltage is applied. The ultraviolet emission in the 140-180 nm range is measured over a wide range of operating conditions. These measurements are complimented by direct metastable state population measurements in excited atomic xenon by tunable laser absorption. Our results provide supporting evidence for the formation of helium-xenon hetero-dimer ions, which may control the electrical properties of the microdischarge. The laser absorption measurements also show quite conclusively, saturation in the production of excited state xenon as pressure is increased, owing to the production of dimer species.