TRANSFORMATION OF THE EMISSION OF RELATIVISTIC ELECTRONS AND METROLOGICAL CHARACTERISTICS OF THE PHOTON FLUX IN THE SYNCHROTRON RADIATION OUTLET OF "NESTOR" STORAGE RING NSC KIPT

Abstract

When setting up experiments involving the use of the polarization properties of synchrotron radiation (SR), a detailed calculation of the spectral angular distribution of SR and its polarization components is of interest. Taking into account the size of the beam shows that in real conditions the radiation propagating in the plane of the equilibrium orbit will not be completely polarized, and the shape and dimensions of the angular distribution of radiation will be distorted. The motion of electrons in the uniform magnetic field and SR of the beam of relativistic particles in the storage ring of the "NESTOR"NSC KIPT are considered. The influence of the size of the electron beam with the energy E=225 MeV on the formation of images of the flux of quanta of SR is analyzed. It is shown that the main contribution to the formation of images is made by the two-dimensional distribution of particles along the vertical and vertical oscillations. A software tool has been developed, the use of which made it possible to simulate the process of forming optical images by the flux of quanta of SR. The formation of images of the radiation of electrons with an energy of E=225 MeV with a change in the longitudinal distance L to the registration plane is considered. It is determined that at small longitudinal distances the main contribution to the image is made by the vertical distribution of particles in the beam. With an increase in the distance, the contribution of the distribution of particles over vertical oscillations increases, which becomes decisive for large L. Numerical simulation of image formation has been carried out. The family of angular distributions of flux density for the σ- and π-components of polarization calculated for one of the SR output channels of the storage ring “NESTOR” is shown. The dependences are presented in the form of two-dimensional histograms for the length Lmax = 300 cm, vertical root mean square size of the beam and different radiation wavelengths, as well as for different dispersions of the electron bunch. The dimensions of the optical window are obtained, the size of which makes it possible to reliably register the entire flux of quanta of SR for the indicated registration characteristics.