Fermilab, Batavia, USA
Space-charge effects have long been recognized as a fundamental intensity limitation in high-intensity linear and circular accelerators. As the mission of the US high energy physics program is pushing the Intensity Frontier, it is very timely to explore novel schemes of space-charge compensation that could significantly improve the performance of leading high-intensity proton accelerator facilities such as Project-X. In this work, we present two activities at Fermilab on the space-charge compensation experiments based on residual gas ionization: 1) neutralized beam transport of continuous-wave (CW) H− beam in Project-X Injector Experiment (PXIE); and 2) trapped electron plasmas for space-charge compensation in the newly proposed Integrable Optics Test Accelerators (IOTA) ring. Characteristics of the stability in the beam-plasma system, the dynamics of beam neutralization, and the transition between neutralized and un-neutralized beam transports are discussed for each configuration.
