Various methods of obtaining longitudinally polarized positrons for future linear col-liders are reviewed. Special attention is paid to the schemes using circularly polarized high-energy photons for positron production. Most effectively such photons are obtained from electrons passing through a helical undulator or colliding with a circularly polarized laser wave. Spectrum and polarization of r...

Recently a mechanism of storage ring operation based on the steady-state microbunching has been proposed and investigated, which contains laser cavity modulator providing longitudinal focusing for circulating microbunches. In this paper we analyze impact coherent undulator radiation single-bunch multi-turn collective dynamics, exploring new possible instability mechanism. We formulate equations...

Undulator radiation from synchrotron light sources must be transported down a beam line the source to sample. A partially coherent photon may represented in phase space using Wigner function, and its transport use some similar techniques that are familiar particle transport. We describe this process case is composed of linear focusing defocusing sections as well apertures. present compact repre...

040702-1 A self-amplified spontaneous emission free-electron laser (SASE FEL) is a device which is based on the creation of a very intense, relativistic electron beam which has very little temperature in all three phase planes. The beam in this system is described as having ‘‘high brightness,’’ and when it is bent repetitively in a magnetic undulator, undergoes a radiation-mediated microbunchin...

Abstract We analyze the undulator and gyro-synchrotron radiation of devices by equating number periods helical trajectory gyrating motion to periods. The gyro is characterized cyclotron resonance maser interaction exhibits superior line width quality but higher sensitive beam energy spread when operated at tera-hertz due finite larmor radius effects.

Techniques are described for at-wavelength interferometry of multilayer coated optics designed for use in extreme-ultraviolet lithography. Broadly tunable undulator radiation, which covers the spectral region from 45 to 400 A, is described. The coherent power available at these wavelengths is described, and several types of interferometer that might be suitable at these short wavelengths are al...

We describe statistical and coherence properties of the radiation from x-ray free electron lasers (XFEL) operating in the post-saturation regime. We consider practical case of the SASE3 FEL at European XFEL. We perform comparison of the main characteristics of X-ray FEL operating in the post-saturation regime with and without undulator tapering: efficiency, coherence time and degree of transver...