Beam behavior under a non-stationary state in high-current heavy ion beams

Three-dimensional beam dynamics in a space-charge-dominated regime during a longitudinal pulse compression is investigated numerically using a multi-particle code developed. Results are compared with those of a two-dimensional particle simulation including a longitudinal current increase model. The rms transverse emittance additionally increases along the drift distance due to the longitudinal motion of the beam particles. The three-dimensional beam behavior can be also compared with a longitudinal one-dimensional calculation under a condition of a constant geometry factor for the transverse direction. Results indicate that the longitudinal beam dynamics are not affected by the transverse motions in the parameter regime.