Issues for generation of long-pulse intense annular relativistic electron beams for relativistic klystron devices

Design and testing of a magnitized, vacuum diode for use in a relativistic klystron amplifier is presented. This diode is to provide approximately 7 GW of electron beam power for 1 microsecond for partial conversion to rf energy by a 2 or 3 cavity klystron amplifier system. The present configuration will be shown. Results of calculations for the magnetic beam optics, electrostatic potential structure, and self-consisitent emission PIC simulations will be presented. Experimental results will be shown of the vacuum diode performance.