Simulation Results with an Alternate 3D Space Charge Routine, PICNIC

One of the major problems in the beam dynamics calculation dealing with high current linacs is the treatment of space charge effects. The widely used SCHEFF routine originated and developed at Los Alamos, is often critiqued as being simplistic because of its inherent assumption of transverse symmetry. Here we report preliminary work on an alternate fully 3D spacecharge routine for a bunched beam. It is a particle-in-cell approach based on numerical-calculation of the interaction between cubes (PICNIC). The principle underlying the method and the comparative results of simulation with SCHEFF and PICNIC are reported.