3d and r,z particle simulation of beams for heavy ion fusion: The WARP code

WARP is an electrostatic particle-in-cell (PIC) code that is optimized for studies of space-charge-dominated beams. The authors use the code to understand a number of issues in HIF accelerators and transport systems, including: drift-compression in the presence of misalignments, axial confinement, longitudinal stability, transport around bends, and thermal equilibration processes. In this paper they describe the code architecture and numerical techniques employed to enhance efficiency. They then describe the new simple algorithm for following a beam around a bend, and recent results on bent-beam dynamics and transverse emittance evolution. Finally, they describe the code's most recent feature, a general-lattice capability structured to preserve the efficiency of the particle advance, and present initial results using it