SEVEN-CELL CAVITY OPTIMIZATION FOR CORNELL'S ENERGY RECOVERY LINAC ∗

This paper discusses the optimization of superconducting RF cavities to be used in Cornell’s Energy Recovery Linac, a next generation light source. We outline the physical constraints in designing these cavities capable of sustaining high beam current (100 mA), with a high bunch repetition rate (1.3 GHz). We discuss the optimization of the seven-cell cavity geometry, both the considerations needed for the center cell design, and results of the end cell design. The optimization aims to: limit the dynamic cryogenic load of the accelerating mode, maintain a low ratio of peak electric to accelerating field to minimize the risk of field emission and maximizes higher order mode damping to suppress beam instabilities. We find a design stable under small shape perturbations, and show that a simulated Energy Recovery Linac constructed from these optimized cavities can support average beam currents of 250 mA.