Experimental study of multipactor on dielectric of penetration flange for vacuum chamber

Abstract

The potential, unexpected occurrence of dielectric multipactor on the dielectric surfaces in high-power radio frequency and microwave components has become a severe constraint in the research and development of space-borne payloads of space vehicles such as satellites and space stations on the ground and their long-term reliable operations in the orbit. In this experimental research, the single-surface multipactor occurring on the dielectric surface of a penetration flange originally designed for a vacuum chamber used in environmental simulation tests of spacecraft is experimentally investigated and compared with the corresponding full-wave simulated results. Under the excitation of periodic pulsed sinusoidal signals, the unusual experimental phenomena of intermittent local jumps of nulling signals in the process of multipactor are repeatedly observed based on an agile nulling experimental system. Taking advantage of the full-wave, three-dimensional (3D) particle-in-cell simulation tool, CST Particle Studio, the entire evolution process of the dielectric multipactor, from its onset to its saturation, is simulated and carefully examined. Combining the results obtained by full-wave 3D particle simulations, some physical explanations and discussion on such phenomena are presented. It is found that under the configuration parameters of pulse signals adopted in this multipactor experiment, the transition of a single-surface dielectric multipactor from its onset to the saturation state can be finished within a single pulse. However, its transition from the saturation state to turning off can last between consecutive pulses in the absence of any high-power radio frequency signals. The obtained result is important for both the theoretical study and the engineering development of high-power dielectric components, providing a new understanding of the dielectric multipactor occurring under the excitation of pulsed high-power electric fields.