Electron beam size diagnostics using diffraction and transition radiation

Abstract

In this dissertation we present our work on developing new beam monitoring methods for linear accelerators and free-electron lasers. Our current work concentrates on the diffraction radiation based beam monitoring technique and compare it with the well-known transition radiation method. We developed a movable slit to generate and to investigate the properties of diffraction radiation generated from various radiator configurations.

The electron bunch profile of the W. M. Keck FEL was measured by using coherent radiation. We performed bunch length measurements based on Gaussian assumptions using coherent diffraction and transition radiation. The results are in good agreement with the PARMELA simulations and observations based on the quality of the FEL light output. These measurements are the basis of an upcoming development of an electro-optic bunch length monitoring system.

We measured the angular distributions of single slit diffraction radiation. These measurements are the initial preparation of diffraction radiation interferometry measurement to obtain transverse beam sizes and beam divergence.

All the measurements were performed at the W.M. Keck FEL Center at Vanderbilt University, Nashville, TN.