Vacuum breakdown remains a key obstacle to achieving higher accelerating gradients in next-generation particle accelerators. Despite decades of study, the microscopic mechanisms that trigger this abrupt failure of RF cavities under extreme electric fields are not fully understood. This talk presents a modeling-based perspective on how electric fields and thermoelastic stresses interact to form breakdown precursors. Using atomistic molecular dynamics and continuum finite-element modeling, we quantify two primary surface roughening pathways—plastic deformation and surface diffusion under the combined actions of electric fields and mechanical stresses. The results reveal a synergistic, multi-mechanism process for breakdown initiation under accelerator-relevant conditions, offering new insights into material design and performance limits.
Copyright. All Rights Reserved.