The effect of grooved surface on dielectric multipactor

Abstract

The effect of periodic rectangular grooves on vacuum multipactor has been theoretically and experimentally investigated. Dynamic calculation is applied to research the electron trajectory and impact energy under groove surface. Two-dimensional electromagnetic particle-in-cell simulation is used to analyze and compare multipactor scenario, statistic energy, and secondary emission yield on the flat surface with that on the corrugated surface. It has been found by computational and simulative analysis that grooved surface can explicitly suppress multipactor in the developmental stage of multipactor. S-band high power microwave (HPM) dielectric breakdown experiment under vacuum, with microsecond pulse length was conducted. It was confirmed by experiment that periodic grooves perpendicular to the major electric field can effectively increase transmitted power.

Suppressing high-power microwave dielectric multipactor by the sawtooth surface

“…Figure 5 shows the setup of the breakdown experiment. 12 Pulsed klystron, operating at frequency 2.86 GHz, was used in the experiment. TE 10 dominant mode is propagated in the rectangular waveguide with sectional area 72ϫ 34 mm 2 .…”

“…8,9 Changing the surface profile by periodically grooving has been found to obviously increase the transmitted power in S-band high power microwave ͑HPM͒ window breakdown experiment both at 90-120 Torr pressure 10,11 and under vacuum. 12 The effect of the oblique rf electric field on the multipactor susceptibility has been analyzed. 3 However, the direction of the microwave electric field, which is dependent on the mode as well as the boundary conditions of the metallic waveguide or horn, is usually parallel to the dielectric window surface.…”

Combining microwave beams with high peak power and long pulse duration

“…Efforts have been made on increasing the output power, pulse duration, conversion efficiency, and the frequency spectrum of the HPM devices. However, limited by material technology and so on, [12][13][14][15] the approaches for enhancing the output capacity with a single HPM source have encountered some difficulties. Another method for enhancing the output capacity of HPM sources is taking advantage of incoherent microwave beam combining of several HPM sources.…”

Design and Experiments of the Gw High-Power Microwave Feed Horn

“…Periodic rectangular and triangular surface profiles with period p ∼ 2 mm have been found to increase the breakdown threshold of dielectric window at the vacuum side, by the theoretical analysis and recent HPM experiments [27,28].…”