Radar REMPI Diagnostic for Low Neutral Density Measurements of Xenon in Helium Buffer Gas: Experiments and Modeling
Conference Paper
Overview
Identity
Other
View All
Overview
abstract
2018, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved. In order to accurately use Radar REMPI as a diagnostic technique, care must be taken to consider how to extrapolate the electron and neutral atom number densities from a given signal. We investigate the dependence of the Radar REMPI signal on the electron collision frequency, specifically in xenon-helium (Xe:He) mixtures, where helium is the buffer gas and the concentration of xenon is 10 ppm or less. We develop a 0-dimensional kinetic model with REMPI ionization to determine the effects of the collision frequency on the signal amplitude and determine a quantitative map between the signal obtained and the neutral xenon density. Good agreement is shown for 1 ppm xenon in atmospheric pressure (760 Torr) helium, indicating the importance of modeling the plasma parameters to more accurately assess the signal. An upper bound for the cross-section of two-photon excitation from the ground 5p6 1S0 state to the 5p56p[5/2]2 state of xenon by circularly-polarized light is computed.