Mathematical analysis of microwave breakdown in flowing gases

The theory of microwave breakdown has been considered under special mathematical conditions which approximate those present on a space vehicle. In particular, models have been considered which assess the effects of gas flow past the antenna system and several different diffusion layers. It is found that gas flow can increase the breakdown field strength at lower altitudes, while having little or no effect at the higher ones. Also, an ambipolar diffusion layer can significantly lower the breakdown field strength at the higher altitudes. In fact, it is found that even a very thin ambipolar layer can exert a large effect upon breakdown. In addition, the problem of breakdown within a half-sphere has been studied. The results of this analysis should be useful in experimental programs. Finally, in the Appendix the general physical theory of breakdown is analyzed starting with the Boltzmann equation.