PHASE DAMPING IN THE SNS LINAC

Abstract

Synchronous phase oscillations and the beam phase adiabatic damping curves in the SNS linac are studied with linac models and measured with all the linac beam phase monitors. This study provides a new beam diagnostic technique for detecting RF cavity phase and/or field amplitude errors in a linac with many independently phased cavities. The phase damping curves predicted in the linac longitudinal model could also be utilized to analyze the longitudinal lattice of the superconducting linac - in which each cavity gradient varies widely from the nominal design and a smooth longitudinal focusing is very important to preserve beam emittance in the linac.