SPECS: Small Particle Electron Cooling Simulations

75647S The premier nuclear physics accelerator facility, the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory, is colliding heavy ions to create conditions like those a fraction of a second after the big bang. An electron cooling section is being planned as part of a luminosity upgrade. Because the parameters and conditions for this electron cooling section will be fundamentally different than those built at other accelerator facilities, the research and design process will require high-performance, high-fidelity numerical simulations. This project will develop a parallel three-dimensional particle code that incorporates novel features for the detailed simulation of the electron cooling section planned for the RHIC. In particular, a "smart" particle algorithm will be used to incorporate the physics of Coulomb collisions, enabling the simultaneous capture of space charge effects and thermal energy transfer. In Phase I, a proof-of-principle implementation of the smart particle algorithm was developed within a parallel particle-in-cell code. The importance of relativistic effects on thermal exchange via binary Coulomb collisions was found to be a modest concern for the case of large emittance electron beams. Relativistic treatment of space charge forces was shown to be important. In Phase II, a three-dimensional, semi-analytic algorithm for binary collisions will be implemented. The replacement of the expensive superconducting solenoid with a long ¿wiggler¿ magnet will be simulated in detail, and the ¿smart particle¿ implementation will be completed. The algorithm will be used to simulate the combined effects of space charge forces and thermal transfer, due to Coulomb collisions, during multiple passes through the cooling section. Commercial Applications And Other Benefits as described by the awardee: The parallel 3-D code should benefit scientists working to design the electron cooling section for the luminosity upgrade to the Relativistic Heavy Ion Collider. This code also should provide an excellent starting point for modeling: (1) the Boersch effect in the transport of strongly-magnetized electron beams for coolers, (2) the intrabeam scattering effect in heavy ion accelerators, and (3) the formation of crystal beams.