Microphonics in superconducting linear accelerators and wavelength shifting in free electron lasers

Mechanical vibrations (microphonics) can degrade electron beam quality in linear accelerators. Since these are often used as electron sources for Free Electron Lasers (FELs) the optical beam quality of the FEL can also be affected. This thesis includes a study of the microphonic problem in superconducting linear accelerators and outlines methods of structure and cryo-module design that correct this problem. Feedback stabilization may also be used to improve the FEL optical beam quality. A study of the optical wavelength shifting mechanism in FELs is presented and the design and performance of an active wavelength stabilization system is discussed.