Simulation and Experimental Verification of Multipactor In Parallel-Plate Microstipline Structure

Abstract

We have developed a comprehensive test setup for producing multipactor in a parallel-plate microstripline structure, with the goal of studying suppression strategies. This setup features broad frequency bandwidth, low-loss, high-power handling, adjustability, and flexibility to perform a wide range of multipactor experiments with different surface shapes and materials. We are able to conduct experiments from 0.1 to 1.2 GHz in ultra-high-vacuum or various gas fills. Multipactor growth will be detected by a sensitive current-detection probe and measurements of RF wave perturbation by the discharge plasma. The probe signal triggers a shut-down circuit, with an adjustable threshold, to turn off the RF power and limit the multipactor event time1. We have generated predictions of the multipactor susceptibility window (RF power vs frequency) using CST particle-in-cell simulations. The simulation predictions agree well with previously published theoretical model predictions2, We will experimentally validate the susceptibility window predictions, followed by experiments to suppress multipactor using either waveform modulations or modifications to the microstrip conducting surface.