High-Quantum-Efficiency Photocathode Development

Navy free-electron laser (FEL) weapon systems require robust long-lived cathodes for the electron injector. The cathodes must deliver very high bunch charge in extremely short time at high repetition rates. AES has been working with Brookhaven National Laboratory (BNL) through a Phase I NAVY SBIR and a JTO contract to develop manufacturing and physics requirements with a goal of fabricating a diamond capsule comprising a primary cathode and diamond amplifier. The diamond amplifiers use secondary electron yield to increase the number of electrons from the primary cathode to amp levels. AES has designed and built a cathode preparation chamber that is compatible with the multi-alkali and dispenser options for the primary cathode. We propose to develop the fabrication process that joins the primary cathode with the diamond amplifier. The output of the project will be progress in the development of the highly desirable diamond amplified cathodes and an experimental evaluation of the fabrication procedures developed specifically for the diamond capsule.