Beam dynamics studies for heavy ion fusion drivers

A quantitative understanding of space-charge-dominated beam dynamics issues is essential to the development of a cost-effective driver for heavy-ion beam-driven inertial fusion energy (Heavy Ion Fusion, or HIF). A multilaboratory "working group" is collaborating to develop such an understanding via detailed computer simulations, benchmarked versus experiments where possible. This work is motivated by the need to plan for an "Integrated Research Experiment" (IRE) facility to be proposed for construction, and for magnetic quadrupole beam transport experiments planned for the very near term. We began by identifying the issues which must be addressed; developing a model IRE design; and conducting "baseline" transverse WARPxy-code simulation studies of the central nominal-energy portion of the beam, for an ideal error-free version of that design. Current work is examining the effects of a wide spectrum of mismatches (including head-to-tail effects), errors, and imperfections, which establish the allowable tolerances and ultimately constrain the design. We are beginning to employ WARP3d to perform integrated time-dependent 3-D simulations from the source through the end of the machine.