One-step tuning algorithm forπ-mode cavities

Abstract

Cavities for p-mode operation are used in existing accelerators and are being built for many future systems. One of the steps in cavity construction is tuning individual cells within the cavity to ensure that the absolute values of relative peak on-axis electric field amplitudes in each cell are equal. This process may have multiple iterative steps: measuring the on-axis fields using bead-pull techniques, employing tuning methods to perturb the cells, making cell adjustments, and then repeating the process on the basis of the new results. This paper describes a one-step process for an N cell cavity that provides the necessary adjustment for each cell to achieve equal field amplitude absolute values from one bead-pull measurement. In addition, a method is shown for inferring relative cell fields while a cavity is operational in an accelerator complex.