Investigation of resonant polarization radiation of relativistic electrons in gratings at small angles

Abstract

The resonant optical polarization radiation (ROPR) in the Smith–Purcell geometry and the one from the inclined grating at the Tomsk synchrotron and 6-MeV microtron have been investigated. The polarization radiation was observed at 4.2° from the 200 MeV electron beam and at 5° from the 6.2 MeV electron beam. Two methods of measurement of ROPR maxima in these two cases have been used. In the first case (the experiment on synchrotron) we have fixed the wavelength of radiation using an optical filter; the orientation dependence of this radiation was measured. In this dependence we have observed two peaks of radiation from electrons in gold foil grating of 0.1 mm period. The first large peak is a zeroth order peak in direction of specular reflection, and the second one is the first-order peak of resonant polarization radiation. In the experiment on microtron the spectra of ROPR from aluminum foil strip grating of 0.2 mm period in the Smith–Purcell geometry were measured, and the peak of the first-order Smith–Purcell radiation in these spectra was observed. The comparison of data obtained with the simulation results has been performed.