Experimental verification of improving high-power microwave window breakdown thresholds by resonant magnetic field

Abstract

Recently, high-power microwave (HPM) dielectric multipactor is theoretically discovered to be suppressed by utilizing external resonant magnetic field. This paper gives the related experimental demonstration of increasing the vacuum window breakdown thresholds. In the S-band HPM experiment with 0.5 μs width, the magnetic field with gyrofrequency Ω close to rf frequency ω can triple the breakdown threshold. Besides, reducing or enhancing magnetic field resulted in a relatively lower threshold in comparison of Ω∼ω, agreeing with theoretical analysis. By HPM pulse compression to 14 ns width, the threshold was also demonstrated to be significantly enhanced by magnetic field.