Laser polarization of positron beam

For a number of physical studies which are planned to be made with the next generation colliders, it is necessary to use polarized beams of both electrons and positrons. The problem of producing and acceleration of polarized electrons may be considered to be solved, but the existing approaches to create polarized positron beams do not ensure the parameters required. This work proposes a new approach to produce polarized positron beams, which is based on the process of multiple Compton backscattering of unpolarized ultrarelativistic positrons in the field of intense circularly polarized laser wave

Resonant Diffraction Radiation from an Ultrarelativistic Particle Moving Close to a Tilted Grating

A simple model for calculating the diffraction radiation characteristics from an ultrarelativistic charged particle moving close to a tilted ideally conducting strip is developed. Resonant diffraction radiation (RDR) is treated as a superposition of the radiation fields for periodically spaced strips. The RDR characteristics have been calculated as a function of the number of grating elements, tilted angle, and initial particle energy. An analogy with both the resonant transition radiation in absorbing medium and the parametric X-ray radiation is noted.Comment: 17 pages, 12 figures, RevTe

The experimental study of the surface current excitation under the influence of a relativistic electron electromagnetic field

The problem of the surface current excitation in a conductive targets by a relativistic electron electric field as the origin of such radiation mechanisms as diffraction and transition radiation of relativistic electron was considered in frame of both surface current and pseudo-photon methods. The contradiction between these viewpoints in respect to the surface current on the target downstream surface necessitated the experimental test of this phenomenon. The test performed on electron beam of the 6 MeV microtron showed, that not any surface current is induced on the target downstream surface under the influence of a relativistic electron electromagnetic field in contrast to the upstream surface. This is important implication for the understanding of the forward transition and diffraction radiation nature.Comment: Was Presented at the symposium Channeling 2008 (Charged and Neutral Particles Channeling Phenomena), October 25 - November 1, 2008 Erice (Trapani - Sicily), Italy, and was accepted for publication in proceedings of symposiu