Energy Recovery Linac Designs and Studies for Electron Cooling of Hadron Beams

Electron cooling of the hadron beam is required in the next generation of electron-ion colliders (EICs) to maintain uninterrupted high luminosity. The method being pursued at Brookhaven Nation Laboratory’s (BNL) EIC is based on coherent electron cooling (CeC) with a high bunch-charge Energy Recovery Linac (ERL). In Phase I, Xelera Research LLC worked closely with both BNL and Thomas Jefferson National Accelerator Facility (JLab) teams to study multiple concepts for the critical merger and arc sections of a high bunch charge ERL. These sections were designed using comprehensive modeling and global numerical optimization to suppress the detrimental effects of coherent synchrotron radiation (CSR) and space charge (SC). The Xelera team also began to develop a complete start-to-end design to set the stage for the Phase II project. In Phase II, we will partner with BNL scientists to develop complete ERL designs suitable for production use. The first year of the project will focus on the beam dynamics designs, including designs for the injector, merger, multi-pass Linac, merger into the cooling section, demerger into the return line (which includes 180-degree arcs), and final extraction of the energy recovered beam. These activities will blend into relevant beam dynamics studies in the second year, including beam breakup (BBU) simulations, tolerance studies, start-to-end simulations, and beam halo studies. A successful Phase II collaboration will establish Xelera Research LLC as an accelerator design and consulting firm that national labs and industry can reliably utilize for new projects. For example, an ERL-based Free Electron Laser (FEL) is considered to be a potential future path for a EUV lithography light source, and this project would position us to break into that industry. The team at Xelera Research LLC is experienced in designing and building innovative and record setting electron sources, injectors, and beam transport systems. While individuals at our firm are internationally recognized experts, it is our team as a whole that makes Xelera unique in this field.