Experimental study of the spectral, angular and polarization properties of undulator radiation

Abstract

For the investigation of the main characteristics of the undulator radiation and its usage in the vacuum ultraviolet region the magnetic undulator was installed on the SIRIUS synchrotron, which has ten elements of the magnetic field periodicity. The undulator radiation has been produced at this installation and its spectral, angular and polarization characteristics have been measured. It is shown that at relatively small magnetic fields the spectrum has a quasilinear character. With the rise of the magnetic field strength in the undulator the position of the first harmonic is displaced to the long-wave region and the part of the higher harmonics is increased in the spectrum. A strong dependence of radiation on the observation angle has been found, i.e. with the rise of the observation angle the spectrum was rapidly displaced to the long-wave region. The angular distribution of two nutually perpendicular components of the linear polarization for different harmonics of radiation was measured. The method of measuring the electron angular spreading in the beam using the undulator radiation is discussed. The experimental results of such measurements are given.