Electron Beam Surface Modification for Voltage Breakdown Suppression

50489-98-I Electron Beam Surface Modification for Voltage Breakdown Suppression--FM Technologies, Inc., 10529-B Braddock Road, Fairfax, VA 22032-2236; (703) 425-5111 Dr. William Peter, Principal Investigator Dr. Frederick Mako, Business Official DOE Grant No. DE-FG02-98ER82582 Amount: $75,000 Electrical breakdown is a critical limiting factor for achieving the necessary voltage gradients in accelerating structures such as the output cavities of the 100 megawatt klystron being developed for the Next Linear Collider. Conventional approaches to increasing voltage breakdown thresholds are often expensive or impractical. The overall objective of this project is to increase voltage breakdown thresholds in high-gradient radio-frequency accelerating structures through surface modification of oxygen-free high-conductivity copper components by irradiation with a high-energy-density electron beam. An existing electron beam source will be modified to achieve the required energy density for surface modification. Voltage breakdown thresholds of copper disks before and after treatment will be measured with an existing test stand and compared. Comparisons will also be made to disks coated with a proprietary coating used to suppress voltage breakdown. Commercial Applications and Other Benefits as described by the awardee: This project will provide a new and effective means for increasing voltage holdoff and lowering dark current levels in radio-frequency structures in consumer, military, and research applications such as the high-power klystrons which are under development at the Stanford Linear Accelerator Center._