Download or read book Theoretical Study of Novel Concepts for Compact, High-gain Free Electron Lasers written by Panagiotis Baxevanis and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, the free-electron laser (FEL) has demonstrated its value as a tunable source of bright, coherent radiation with photon energies up to the X-ray region. For such short radiation wavelengths, three-dimensional (3D) effects (due to diffraction, emittance and focusing) become significant and must be taken into consideration. In this work, we present a systematic, fully 3D theoretical formalism applicable to a range of concepts for compact, high-gain FELs. These include novel schemes involving the use of transverse gradient (TGU) or laser undulators. Our approach utilizes either a standard eigenmode analysis for constant-parameter systems or a non-eigenmode expansion technique in terms of orthogonal transverse modes for cases where the parameters of the electron beam and/or the undulator vary along the longitudinal direction. The results we obtain fully characterize the system (electron beam and radiation) in the linear regime of the interaction and are shown to be in excellent agreement with simulation. Moreover, the formalism developed here can be used in comprehensive, theory-based optimization studies, with significant applications in FEL design.