Ion Composition Detection in High Temperature Plasma

As the USAF works towards extending the performance envelope of its moder high performance aircraft and advanced re-entry vehicles, it is beginning to encounter multiple problems created by the presence of high temperature plasmas. The source of the plasma may vary from a jet or rocket engine plume to the sheath and wake plasmas caused during the re-entry of hypervelocity vehicle; however, understanding the nature of these plasmas, their effect on Air Force weapons systems, and the development of methods to alleviate any detrimental effects of these plasmas will depend upon our ability to accurately measure the chemical knietics that define the plasmas properties. Given the current state-of-the-art in plasma diagnostics, the quadrupole mass spectrometer, properly designed for high-temperature, high-velocity plasma flow measurements is an ideal candidate for this task. Given the stressing environment, the technical problems are formidable. Great emphasis will be placed upon design of the inlet nozzle, its effect on the flow of the plasma and its ability to avoiddisturbing the chemical structure of the stream during the sampling process. The disturbing the chemical structure of the stream during the sampling process. The goal of this research is to design av rugged, versatile mass spectrometer system that achieves accurate reproducible measurements of the ion population of high temperature plasmas.