Investigating Secondary Electron Yield (SEY) of Materials of Interest for High Power RF and Microwave Devices*

Communication satellites rely on microwave vacuum electron devices which are critical components, but their performance can be degraded by Multipactor breakdown (MPB) due to high secondary electron yield (SEY). Identifying materials with low SEY, including perforated Cu transmission line structures that have shown reduced susceptibility to the MPB is crucial to prevent device destruction, especially for high power vacuum electron devices used in space applications and multicarrier communications. Measurements are being made in an existing test stand, recently modified to enable measurements on insulators as well as conductors by using pulsed and steady-state e-beams, highlighting the importance of characterizing SEY through different methods. SEY is a highly surface-sensitive process, influenced by sample handling and treatment methodologies. Furthermore, studies on porous Cu samples have shown a trend of decreasing SEY with increasing porosity. The SEY results will be shown in this presentation to provide valuable insights into materials and surface properties that can potentially mitigate MPB risks. The goal is to enhance device reliability, minimize MPB-induced failures, and ensure the long-term operation of microwave vacuum electron devices in communication satellites.