Coherent Radiation of Relativistic Electrons in a Wire Metamaterial

We present in this work the experimental investigation of the interaction of relativistic electron field with wire metamaterial. The measurements of the spectral-angular characteristics of coherent radiation were done in millimeter wavelength region in far-field zone at the relativistic electron beam with energy of 6 MeV. Used target represent the right triangular prism that consist of periodic placed copper wires. We showed that bunched electron beam passing near wire metamaterial prism generates coherent Cherenkov radiation. Spectral angular characteristics of radiation from the wire target were compared with the characteristics of Cherenkov radiation generated in similar experimental conditions in a dielectric target (Teflon prism) that has the same form and sizes

Coherent Radiation of Relativistic Electrons in Dielectric Fibers for theBeam Diagnostics

The possibility of using radiation of relativistic electrons in optical fibers using the properties of dielectric materials for diagnosing beams was theoretically suggested by the authors X. Artru and C. Ray. (Nucl. Instrum. Meth. B vol. 309 (2013). The aforementioned work studies the properties of various types of radiation induced in fibers by the electromagnetic field of relativistic electrons. In this paper, we present the experimental research of the influence of surface waves on the radiation propagating along a fiber. The work also investigates the properties of various types of coherent millimeter wave radiation that was induced in dielectric fibers by the electromagnetic field of relativistic electrons. The results also include the experimental analysis of nature and properties of coherent radiation in fibers, the analysis being performed for different positions of fiber in relation to the electron beam.</jats:p

Monochromatic coherent transition and diffraction radiation from a relativistic electron bunch train

Electron beams of most accelerators have a bunched structure and are synchronized with the accelerating RF field. Due to modulation of the electron beam with frequency v[RF] one can expect to observe resonances with frequencies vk= k·v[RF] in radiation spectrum generated via any spontaneous emission mechanism (k is an integer and the resonance order). In this paper we present the results of spectral measurements of coherent transition radiation (CTR) generated by an electron bunch train from the Tomsk microtron with v[RF]=2.63GHz in the spectral frequency range from 8 to 35 GHz. We also measured the spectrum of coherent diffraction radiation and demonstrated that the observed spectra in both cases consist of monochromatic lines. For spectral measurements the Martin-Puplett interferometer with spectral resolution of 800 MHz (FWMH) was employed. Using a waveguide frequency cut-off we were able to exclude several spectral lines to observe higher resonance orders of up to k=7

Characteristics of Smith-Purcell radiation in millimeter wavelength region

Investigations of the Smith-Purcell radiation (SPR) were began with non-relativistic electron beams with some unexpected experimental results. Further the experimental investigations were performed with relativistic electron beams for application to beam diagnostics. Large discrepancy between different theoretical models significantly increases the role of experimental studies of this phenomenon. In this report we present some problems and features of experimental investigations of SPR in millimeter wavelength region. The problems of prewave zone and coherent effects are considered. The shadowing effect, focusing of radiation using a parabolic SPR target and effect of inclination of target strips were investigated with moderately relativistic electron beam