Longitudinal Space-Charge Waves Induced by Energy Modulations

Abstract

High intensity beams that are space-charge dominated are important for applications such as free electron lasers that require high intensity and low emittance beams. Modulations in energy or density can induce space-charge waves at low energies which could be problematic at higher energies. This thesis is a study of longitudinal space-charge waves induced by energy modulations within a highly space-charge dominated beam propagating in the University of Maryland Electron Ring (UMER). Using an induction cell, we present the first UMER experimental results on the design and application of the cell to place energy perturbations. We compare the results to one-dimensional cold fluid theory and simulation. We allow the perturbation to propagate for over 60 m so that we can get a turn by turn measurement of the experimental sound speed. In some of the turn by turn data, we obtain a 4.8% disagreement between the experimentally measured sound speed and theory.