Characterization of Materials with Low Secondary Electron Emission Yield for High-Power Microwave Devices

Summary form only given. Over the last few years, there has been a great deal of interest in secondary electron emission (SEE) phenomena. SEE results from the interaction of materials with electrons, atoms, or ions. The amount of secondary emission depends on factors such as the bulk and surface properties of materials, the energy of incident particles, and their angle of incidence. When studying SEE, one is interested in determining the total secondary electron emission yield, which is defined as the number of secondary electrons produced per incident primary electron. The goal of our research is to identify novel materials (with a very low SEE yield coefficient) that will make high-power microwave devices more efficient and robust. To this end, we have employed a low-energy electron gun (5 eV to 2000 eV) to characterize different materials. These measurements have been performed in the DC regime, but pulsed mode measurements are planned for the future to supplement the data. In addition, in support of the experiments, ICEPIC (improved concurrent electromagnetic particle-in-cell) simulations of SEE will be performed. Results obtained to-date will be presented