Development of 3D simulations for heavy-ion fusion beam transport and compression problems

Longitudinal beam compression and the possibility of concurrent pulse shaping have been the subject of previous studies using analytical methods and 1D and 2D codes. Here we report on a code development effort to study 3D beam transport in quadrupoles and final compression of a drifting heavy-ion beam pulse. As part of this effort we are making improvements to the ARGUS particle-in-cell (PIC) code to investigate 3D effects of magnetic quadrupole beam transport. A system with magnetic-quadrupole focusing fields is realistically three-dimensional. Although magnetic quadrupoles are expected to be an integral part of much of the heavy-ion accelerator driver, the restrictions due to space-charge modifications of the beam are particularly acute during final compression and focusing, and so we concentrate on this stage. Our initial preliminary benchmarking runs are presented. (orig.)