Theory of Nanosecond High-Power Microwave Breakdown on the Atmosphere Side of the Dielectric Window

This paper deals with the theory of plasma development in the nanosecond high-power microwave breakdown at the dielectric/air interface. Utilizing the Poisson and Boltzmann equations, the basic physics are explored and investigated. Corresponding to the incident electric field, electrons moving back and forth bring about the negative charge accumulation at the interface. This process generates an extra electric field, strengthening the total amplitude. Simultaneously, deviations of electrons and ions lead to a sheath region providing a space charge field. Secondary electrons are strongly accelerated in the sheath region, eventually leading to an ionization avalanche in a very short time. Both the densities and energies of particles reach the maximums near the sheath region, and that is why the illumination is most significant near the interface. The theory is in good accordance with an experiment conducted under the same conditions.