Modeling Electron Cloud Diagnostics for High-Intensity Proton Accelerators

Electron clouds in accelerators such as the International Linear Collider (ILC) degrade beam quality and limit operating efficiency. The need to mitigate electron clouds has a direct impact on the design and operation of these accelerators, translating into increased cost and reduced performance. Diagnostic techniques for measuring electron clouds in accelerating cavities are needed to provide an assessment of electron cloud evolution and mitigation. Accurate numerical modeling of these diagnostics is needed to validate the experimental techniques. This project will develop detailed numerical models of microwave propagation through electron clouds in accelerating cavities with geometries relevant to existing and future high-intensity proton accelerators. The massively parallel three-dimensional plasma simulation code, VORPAL, will be used. The effects of non-uniform electron density distributions will be included. Commercial Applications and other Benefits as described by the awardee: The ability to numerically assess the efficacy of electron cloud mitigation techniques, such as surface roughening and the use of alternative coating materials, should lead to significant time and cost savings for both DOE-funded research institutions and commercial manufacturers of accelerator components.