Electron gun and CVD diamond window for a 346 GHz sheet beam BWO

A collaboration between UC Davis, Lancaster University, Beijing Vacuum Electronics Research Institute (BVERI), and the University of Electronic Science and Technology of China (UESTC) is developing a 346 GHz backward wave oscillator (BWO) for use as a source in plasma fusion diagnostics, medical, biological, and security imaging systems. Development of new electron gun optics that achieve almost 100% beam transmission based on particle-in-cell simulations is presented along with comparisons of the cold and hot beam performance. Also, a CVD diamond pillbox window design is presented. Additionally, the mechanical layout of the devices is being completed and prepared for fabrication.