High-current micro-pulse electron guns and accelerator applications

A major research activity is being pursued at FMT to develop high-current, short-duration pulses of electron beams for injectors in electron accelerators as well as for microwave generation in klystrons and related devices. Design and development of gun cavities, in the frequency range, of 1 to 12 GHz, are conducted through a comprehensive task including simulation, analytical and experimental studies. With the goal to build high-power, high-frequency klystrons, one of our most recent efforts is focused on developing an X-band cavity at about 9 GHz for generating high-current, bunched micropulses of electron beams. The full system has been designed and built, and it is running reliably. An average beam current density >20 A/cm over a macropulse, or 400 A/cm/sup 2/ over a micropulse, has been measured for a modest input rf power, /spl sim/60 kW, into the gun cavity. In addition, experiments are being conducted to develop an electron gun at 1.3 GHz, with gating capabilities, and match beam requirements for the Argonne Wakefield Accelerator.