Development of an electron-ion collider is a priority of the nuclear physics community. The Medium Energy Electron-Ion Collider (MEIC) is a high-luminosity polarized ring-ring design, which includes a magnetized electron cooler with high-charge relativistic ~55 MeV electron bunches. Dynamic friction is the key physics underlying electron cooling. Present design efforts are based on parametric and approximate analytical models for magnetized dynamic friction, which were developed for low-energy cooling systems and do not include the finite time effects that are important at relativistic energies. Fast, accurate simulations of magnetized dynamic friction are required for improved understanding and to reduce risk and cost in the MEIC design. RadiaSoft will develop a fundamentally new and improved parameterization of magnetized dynamic friction, including a simple formula suitable for quick estimates and design studies, and a fast numerical tool that integrates a simple formula over an assumed or a numerically generated electron distribution. RadiaSoft will explicitly include the effects of finite interaction time and asymmetric collisions. RadiaSoft will develop the ability to simulate DC magnetized electron coolers at moderately relativistic energies, including space charge neutralization. We will also develop a browser-based GUI for electron cooling calculations and simulations, building on our open source infrastructure for scientific cloud computing. The proposing team has previously shown how to efficiently calculate unmagnetized dynamic friction, including finite time effects. During Phase I, RadiaSoft will generalize this work to treat the magnetized case, using a fundamentally improved algorithm for electrostatic particle dynamics. The negative effects of space charge forces, magnetic field errors and imperfect magnetization of bunched electrons will be included, and RadiaSoft will explore the potential benefits of space charge neutralization for DC electron beams. RadiaSofts results will be used to fundamentally improve existing parametric models. RadiaSoft LLC is developing software to minimize technical risk for a future electron ion collider, which promises to fundamentally advance nuclear physics and particle accelerator technology. Commercial Applications and Other
Benefits: The proposed work will directly benefit the Office of Nuclear Physics through improved understanding of magnetized electron cooling systems for relativistic beams. This understanding will be used to improve future MEIC designs to reduce technical risk and associated costs. RadiaSoft commercialization strategy is not limited to the beam physics application of this project. RadiaSoft plans to develop a subscription-based website for the publication of computational scientific results, enabling other scientists to immediately reproduce and easily extend previous work. RadiaSoft will begin with particle accelerator simulations using the open source Warp and Synergia frameworks. RadiaSoft simulation containers will create a new market for computational science and engineering, analogous to the academic journal publishing industry.
