To generate uranium ion beam with high current and high brightness to meet the requirement of the heavy ion synchrotron at GSI

KOBRA3-INP code has been used to simulate the behavior of the uranium ion beam in the extraction system and the post-acceleration system for a metal vapor vacuum arc ion source. The influence of the emission current density on the characteristics of the extracted ion beam is discussed. The results show that the losses of the extracted ion beam propagating through the beam line mainly occur in the drift space between the extraction system and the post-acceleration system. Simulation quantitatively supports the experimental results under the assumption that the ion beam has to be space charge compensated along the drift sections. Intensity of the ion beam behind the post-acceleration system is not sensitive to the emission current density in the range from 180 to 230 mA/cm2.