Improving the microwave window breakdown threshold by using a fluorinated, periodically patterned surface

Abstract

The breakdown at the dielectric window of the high-power microwave (HPM) horn limits the maximum radiation power of HPM system, and keeps the bottle neck of the development of the HPM technology in decades. In this paper, the multi-way diagnostics for the window breakdown at vacuum/dielectric interface are studied in the C-band multi-gigawatt HPM experiment with the atmospheric pressure SF6 environment. The method of using the fluorinated periodic surface is demonstrated to significantly improve the power capacity by fourfold, compared with the flat surface. The threshold for fluorinated periodic surface could be higher than 70 kV/cm for HPM with the frequency 4.3 GHz, and 40 ns pulse width.