Space Charge Simulations of First-Turn Experiments on the University of Maryland Electron Ring (UMER)

Emerging particle accelerators require beam brightness and intensity surpassing traditional limits, bringing beams into the realm of nonneutral plasmas where particles interact primarily via long-range collective forces. Therefore the understanding of collective interactions is crucial for successful development of such applications as spallation neutron sources, high energy colliders, heavy ion inertial fusion, intense light sources, and free electron lasers. The University of Maryland Electron Ring (UMER), currently just completed, is designed to be a scaled model (3.6-m diameter) for exploring the dynamics of such intense beams. Using a 10 keV electron beam, other parameters are scaled to mimic those of much larger ion accelerators, except at much lower cost. An adjustable current in the 0.1-100 mA range provides a range of intensities unprecedented for a circular machine. Since UMER is primarily designed to serve as a research platform for beam physics, it is equipped with a vast array of diagnostics providing 6-D phase space measurements for effective comparison against computer codes. Simulations using the WARP code are presented which model recent experiments on transverse and longitudinal beam evolution during the first-turn of UMER