Modeling the propagation of long, intense microwave pulses in mixtures of air and SF/sub 6/

Self-consistent equations-Maxwell's equations and the electron fluid transport equations-are used to study the interaction of long, intense microwave pulses with gases. The threshold for breakdown is a factor of seven higher in SF/sub 6/ than in air. This difference is attributed to the fact that SF/sub 6/ is an insulator. When SF/sub 6/ was mixed with air, the breakdown threshold increased with the increase in the percentage of SF/sub 6/. Introducing 5-10% of SF/sub 6/ in air increased the breakdown threshold by a factor of 3-4. The electron density and conductivity and the plasma frequency increased as the pulse intensity increased. The growth rates of the electron density and conductivity were much higher in air than in SF/sub 6/.<
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