Seminars Archive

Space Charge Beam Dynamics at the University of Maryland Electron Ring

Abstract
Free electron lasers require high-brightness electron beams characterized by strong space charge in the source and injector regions. Fluctuations resulting from the drive-laser or space charge forces near the cathode can be amplified, leading to degraded performance during subsequent beam manipulation stages. The University of Maryland Electron Ring (UMER) is a facility dedicated to the study of space charge beam dynamics. Its non-relativistic, 10 keV electron beam has a current adjustable over the range 0.5 – 100 mA and a pulse length adjustable over the range 5-140 ns. We can introduce controlled density or energy perturbations to the UMER beam in three different ways: by modulating a pulse applied to the cathode grid, by using photoemission from a laser, or by means on an induction cell downstream. UMER has a wealth of phase-space diagnostics. Experiments are supported by a simulation capability centering around the codes Elegant and WARP. This talk will report on the capabilities of UMER and recent studies of longitudinally modulated beams, including the observation of soliton formation and propagation. * Supported by the US Dept. of Energy, Offices of High Energy Physics and Fusion Energy Sciences, and by the US Dept. of Defense, Office of Naval Research and the Joint Technology Office.