FEL mirror response to shipboard vibrations

Abstract

The Optical cavity of a Free Electron Laser (FEL) is composed of components that must be maintained to very tight tolerances. The shipboard environment is one that will preclude a direct coupling of FEL components to the ship. This thesis will explore the basis for these tight tolerances, and how to isolate them from the FEL. A solid model of a potential FEL system will be developed using SolidWorks. This model will then be converted to a finite element model in ANSYS. The finite element model will be used to calculate the system's eigenvectors. These eigenvectors will be used to develop a state space model in MATLAB. Driving functions simulating sea state 6 and under water explosion will then be applied to the state space model and the motion of various components will be tracked. This simulated motion will be used to develop and test a passive control system to damp out the vibrational input to the FEL. It is not possible for a passive system to totally isolate the FEL from excitation by the ship environment. A passive system that minimizes the inputs to an active control system will be developed. An active system that will handle the final mirror stabilization for a FEL optical cavity will be left for further research.