Abstract
A variety of accelerator-based light sources driven by relativistic electron beams, such as storage rings, free electron lasers and energy recovery linacs, have been commissioned and operated around the world. To meet the increasing demands for generating intense coherent radiations from compact accelerator beamlines, new schemes for producing electron beams with corresponding properties have been developed. We introduce several beam manipulation schemes developed for improving the radiation properties in modern accelerator systems. In this dissertation, we focus on the beam dynamics in linear RF accelerator systems, and analyze an interesting distortion phenomenon of electron beams induced by the RF acceleration and space charge fields. To obtain a desired output beam, we take into account the distortion phenomenon and calculate the spatiotemporal distribution of the input beam by using self-developed algorithms. We describe two proposed schemes which rely on the design of the photocathode and advanced optical technologies to realize a tailor-designed spatiotemporal distribution of the input beams during photoemission. The simulation results show that a tenuous density modulation with a frequency between sub-petahertz to a few petahertz can be created in electron beams with the proposed schemes. Such a density-modulated beam is useful to generate coherent radiation at short wavelengths in various accelerator-based light sources. The power of the coherent radiation can be orders of magnitude brighter than that of the incoherent radiation from a randomly distributed beam in an equivalent light source. Of particular interest is the two proposed schemes allow one to conveniently manipulate the beams with additional degrees of freedom. Furthermore, we propose a design of a free electron laser amplification system seeded by a broadly tunable terahertz parametric amplifier laser, in which both the phase space manipulation of the MeV electron beam and amplification of terahertz radiation can be implemented in an undulator.