The 10 keV injector for the University of Maryland Electron Ring Project

The 10 keV, 100 mA, Pierce-type electron gun and injector for the University of Maryland Electron Ring (UMER) Project are described. Using a pulsed control grid located 0.15 mm from the 4-mm radius cathode, 100-ns bunches are generated. The A/K gap is variable, producing beam currents ranging from 50 to 160 mA. A rotatable aperture plate is included to allow six different masks, including a pepperpot. Beam current after the aperture plate is measured with a built-in Rogowski coil. The injector line consists of a solenoid lens, five printed-circuit quadrupoles, and two in-line diagnostic chambers. A separate, multi-purpose chamber is placed at the end of the injector line during gun characterization studies for emittance, profile, and energy analysis.