Modern physics formulates topical problems

There is no doubt that their use will become more widespread in the near future. For example, in all projects of specialized SR sources being implemented and developed to date, the undulator becomes an essential element. The presence on the largest proton synchrotrons of intense beams of high-energy monoenergetic electrons (tens and hundreds of gigaelectronvolts) and the creation of colliding electrons in the near future; positron beams with energies up to 100 GeV will allow, when they are decelerated in an undulator, to generate intense fluxes of polarized quasi-monochromatic photons of high energy (of the order of several megaelectronvolts and above) [12]. Such photons are of independent interest for the production of polarized electrons and positrons in linear colliding electron-positron beams and for research in the field of photonuclear physics and high-energy physics.

Using radiation from a spiral undulator installed in an electron-positron collider, it is possible to obtain fluxes of monochromatic circularly polarized photons arising from Compton scattering of undulator radiation from one of the beams on a counterpropagating beam. The energies of such photons will be close to the energy of the colliding particles. From their angular distribution, one can judge the polarization of the electron-positron beams.

Modern physics formulates topical problems, the solution of which leads to the need to create new tools for collecting information and its subsequent analysis. One of these tools, of course, are the sources of powerful radiation in the X-ray range, which make it possible to operate on various phenomena at the atomic and molecular level; in fact, without this class of devices it is impossible to imagine the study of submicron and nanosystems [12]. Particular attention in the class of the described radiation sources is paid to FELs, which differ in a wide range of operating frequencies, up to soft X-ray ones (at present, it is planned to obtain harder radiation in FELs under construction), coherence and polarization of the output radiation.