Summary form only given. A Vacuum Ultra-Violet (VUV) laser pulseis used to create a plasma sheet in a low-ionization-energy organic gas.Microwaves from a highly directive X-band horn antenna impinge on thesheet where they are reflected. A bi-static antenna system is used fortransmitting and receiving the microwave radiation. Both heterodyne andhomodyne detection systems are investigated for maximum sensitivity.Reflected signals are measured for amplitude and phase analysis.Comparable amplitude and phase shifts are noted when compared to analuminum conducting sheet placed in the same position as the plasma. Theworking gas is tetrakis(dimethylamino)ethylene (TMAE) with an ionizationenergy of 5.36 eV. The ionizing source is a VUV excimer laser operatingat 193 nanometers (6.4 eV). The laser and plasma properties arediagnosed by an optical detection system and by Langmuir probes. Thelaser beam is transformed into a sheet using VUV coated Suprasil lenses(96% transmission efficiency). A plasma sheet with a peak density of2.5×1013 cm-3 and Te=0.8 eV isformed. Additional measurements of transmitted signals are utilized todetermine plasma density and collision frequency. A computer model ofthe microwave transmission and reflection levels has been developed tooptimize reflected signal levels as a function of density and thicknessand to interpret experimental results. Comparison between theexperimental results and the model show that this system is attractivefor use as a microwave reflector
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