A 3D Finite-Element Modeling Tool for Multipacting Analysis

78140S Strong radio-frequency electric fields in high-power components used in colliders can induce a resonant cascade of particles near internal surfaces (called multipacting) that can lead to surface breakdown and device failure, in some cases limiting the power than can be handled to a fraction of the design specification. Existing tools available to analyze this phenomenon have limited accuracy, are inefficient, and are difficult to use, particularly on complex three-dimensional structures. To address the need for improved analysis tools to study multipacting, this project will integrate an established boundary-conforming finite-element particle-in-cell solver with a commercial electromagnetic analysis package. These codes will combine a novel adaptive particle tracking algorithm and advanced secondary models, together with parallel electromagnetic field solvers, comprehensive computer-aided design model building, conformal adaptive meshing, and post-processing functionality. The result will be a production-level capabilility for multipacting analysis in complex two- and three-dimensional structures. In Phase I a prototype capability will be created that orchestrates electromagnetic field solutions, then particle tracking, then comprehensive multipacting data analysis to be displayed to the researcher. This capability will be encapsulated within a new, specialized environment hosted by the commercial analysis package, and will require only minor modifications to the particle tracking code. The new capability will be benchmarked against established solutions for a superconducting radio-frequency cavity and a waveguide power feed. Commercial Applications and Other Benefits as described by the awardee: Multipacting considerations affect a broad class of high-power radio-frequency systems used in commercial and government applications, including microwave tubes, radio-frequency ¿plumbing¿ for high power applications such as radar and microwave telecommunications links, commercial accelerators, and others. The new multipacting analysis capability will be available to the commecial sector, including those companies that support DOE programs, enabling more rapid development, lower costs, and more robust device designs. Moreover, the package will have applications outside of multipacting, such as radio-frequency gun and photoinjector device development.