Magnetostatics, particle trajectories and the electrodynamics in realization of hybrid undulators for high performance FELs and synchrotron radiation sources.

摘要

The construction and commissioning process of the Free Electron Laser Laboratory during the years of 2000-2007 offered unique opportunities to realize many prototype designs and novel developments to enhance the efficiency of laser subsystems. The MKIII FEL Lab is expected to become the central research facility for many projects such as remote sensing, x-ray spectroscopy and medical research.; In this dissertation I report the work done on the MKIII undulator system, the integral part of the FEL, where some of the kinetic energy of the relativistic e-beam is converted into the spontaneous radiation and then coupled to the optical field. I present, justify and describe the system modifications and improvements that were implemented and the apparatuses that were built in support of this effort. The objective is a production of tightly controlled and highly uniform custom magnetic fields of minimal variance such that the electron beam interacts with an optical field while traveling along the central ray of the undulator.; Through numerical modeling, metrology, engineering, experimentation and analysis, I achieved a magnetic field quality, which resulted in the transverse e-beam oscillations of less than 100 (mum) for the e-beam energy of about 45 (MeV). The new maximum value of the undulator parameter, K 2/2, is now about 25% greater than the old maximum value, and an operation of the FEL system at its optimized state, where K 2/2 = 1.2, is now possible. A brand new batch of NdFeB magnetic wafers is now in the undulator, while the entire set of old and damaged SmCo 5 wafers have been removed from the device.; This dissertation is envisioned to serve as a guide and a practical reference document for the conditioning work on FEL undulator systems. Many hands-on methods are described and a thorough mathematical analysis is presented in support of any and all scientific claims contained within this dissertation.