• C. Papadopoulos, I. Haber, R.A. Kishek, P.G. O'Shea, M. Reiser
  UMD, College Park, Maryland

Beam halo is one of the major limiting factors to the effective transport of intense beams. In this paper, we use the WARP particle-in-cell code to numerically investigate the effect of different initial particle distributions on the properties of mismatch-induced halo. In particular, we use equilibrium and non-equilibrium distributions, the latter prompted by experimental measurements of the beam distribution in the University of Maryland Electron Ring (UMER). In both cases, we observe the phase space structure expected in the case of resonances between beam envelope oscillations and single-particle trajectories.