Speaker: Jan Paszkiewicz (BE-RF-LRF)
A new approach to breakdown limits
A novel quantity for predicting the ultimate performance of all kinds of high-gradient radiofrequency accelerating structures is presented and compared with earlier quantities that it builds on such as the modified Poynting vector. This new method models a nascent RF breakdown as a current-carrying antenna and calculates the coupling of the antenna to the RF power source. Along with a simple emission model fitted to experimental data, an equilibrium breakdown-loaded surface electric field distribution is calculated and found to be well-correlated with spatial breakdown distributions in a wide range of situations beyond a standard accelerating structure, such as deflecting cavities, structures with magnetic coupling, and DC experiments. This new method has a strong physical justification, very broad applicability, and potentially strong implications on the future of high gradient design.