Magnetized Electron Transport in the Proposed Electron Cooling Section of the Relativistic Heavy Ion Collider

72925 One of this country's premier nuclear physics accelerator facilities is colliding heavy ions to create conditions similar to those a fraction of a second after the Big Bang. An electron cooling system, to be built as part of a planned luminosity upgrade, will have parameters and requirements fundamentally different from any built previously, and there is a need for high-speed, high-fidelity numerical simulations to assess the impact of space-charge, nonlinearities, and machine errors on the electron transport line. There exists already a parallel 3-D code that includes the effects of space-charge and magnet nonlinearities. We will add needed functionality to this code to make it a suitable tool for doing high-fidelity simulations and analysis of high-current magnetized electron transport lines, including misalignments and nonlinear rf accelerating fields. We developed and implemented methods to extract from electric field data the information required to construct high-order maps for rf cavities. We have defined an approach for adding general misalignments to a high-order beam dynamics code. And we have applied this code to tracking simulations of an electron transport line that is currently under research and development. We will complete the implementation of accurate, high-order maps for RF cavities, and implement general misalignments. In collaboration with scientists at government labs, we will use the improved code to make detailed studies of a novel electron transport line currently under design. We will also develop a suite of tools---input file converters, post-processing utilities, and the like---that will make it easier for scientists to compare with simulations done by different codes. Commercial Applications and Other Benefits as described by awardee: The proposed code will benefit scientists working to design accelerators in which space-charge, field nonlinearities, and machine errors are significant concerns. We expect that scientists who develop expertise in this area will be in demand for future non-SBIR contract work.