Designing a Coherent Electron Cooling System for High-Energy Hadron Colliders

The future electron-ion collider will have an ion luminosity that is orders-of-magnitude higher than current systems. This high luminosity will require cooling of the ion beam. An exciting concept known as ¿coherent¿ electron cooling (CEC) combines the best features of electron cooling and stochastic cooling, to enable the cooling of >250 GeV proton bunches and other high-energy hadron beams with order-of-magnitude shorter cooling times. However, the CEC concept is unproven and requires detailed simulation of its key components. This project will develop a code suite for the design of future CEC systems. The challenge is to accurately characterize the effective velocity drag on an ion, as a function of its initial velocity. Phase I demonstrated the correct simulation of a single ion in the ¿modulator¿ of a CEC section, in which ions imprint a signature (i.e., wake) on the electron density and velocities. Phase II will involve characterizing the effective velocity drag on an ion. Possible mechanisms for reducing the velocity drag ¿ including shot noise, overlapping wakes due to the presence of many ions, boundary effects in a finite-sized electron beam, and transverse ion dynamics between the modulator and the kicker ¿ will be explored. Commercial Applications and other Benefits as described by the awardee: The new capability should directly benefit DOE funded scientists working to design electron cooling systems for future electron-ion collider concepts. In addition, the proposed work would further enhance the parallel VORPAL framework, which is already a successful commercial product