Advanced Computational Tools for Modeling Coherent and Microbunched Electron Cooling Systems

Statement of the problem or situation that is being addressed: The electron cooling system for the proposed luminosity upgrade of the Relativistic Heavy Ion Collider (RHIC), and for future electron-ion collider concepts, represents a significant design challenge due to the high energy of the ion beam. An innovative concept known as coherent electron cooling (CeC) combines the best features of electron cooling and stochastic cooling, via free-electron laser (FEL) technology, to offer the possibility of cooling high-energy hadron beams with orders-of-magnitude shorter cooling times. Microbunched electron cooling (MBEC) and other variants of the CeC concept that rely on mechanisms other than the FEL instability promise to improve cooling efficiency by another 2-3 orders of magnitude. CeC could dramatically increase the scientific productivity of RHIC and may be the only viable approach to enable future electron-ion collider concepts. Simulation has played a key role in designing the proof-of-principle (PoP) CeC experiment, currently under construction at RHIC. Because the underlying physical principles are complex and the proposed technological solutions are beyond the current state-of-the-art, more detailed simulations and thorough design optimization are needed in order to reduce technical risk. How this problem is being addressed and what is to be done in Phase I: By the end of the Phase II of this project we will develop a versatile and easy to use software product for high-fidelity start-to-end simulation of coherent electron cooling, including both FEL- based and MBEC schemes. We will rely on best software design practices to ensure superior performance on modern parallel platforms. In the Phase I we will demonstrate the feasibility of extending VSim-based capabilities for modeling the FEL-based CeC concept to enable modeling of other CeC variants such as MBEC, and will prototype key technologies required to perform such an upgrade and improve the overall fidelity of CeC simulations. Commercial applications and other benefits: VSim (previously, Vorpal) is a commercial software for simulation of a wide range of elec- tromagnetic and electrostatic phenomena, including the nonlinear kinetic behavior of beams and plasmas. Extending the range of VSims electron cooling modeling and design optimization capa- bilities will create opportunities for VSim sales to, and associated contract revenue from, electron cooling groups in the U.S. and abroad. There will also be possibilities for future non-SBIR revenue in this area from U.S. labs or funding agencies. Successful completion of the proposed effort will produce commercial quality software for multiphysics modeling on multiple timescales that will be marketed to the microwave device, lightning strike protection, and other industries. There are many opportunities for commercial sales of our software in the computer-aided engineering market. Keywords: coherent and microbunched electron cooling, electron-ion collider, start-to-end simulation Summary for members of Congress: Novel computational tools are being developed to assist Department of Energy scientists in the design of a premier nuclear physics facility for the study of quark-gluon structure of matter. Resulting state-of-the-art software will also be sold in the computer-aided engineering market to meet the demand for similar computational capabilities.