At present, a fourth-generation synchrotron radiation source USSR (Synchrotron & Laser), which will the one of the world’s largest scientific centers is being designed in Russia. Its creation will make it possible to carry out experiments to study the structures of a wide range of objects in various disciplines at a qualitatively new level compared to the previous generation of sources. The overall facility layout includes a 6 GeV main storage ring and a linear electron accelerator (linac) at full energy. It is proposed to use one linear accelerator with two RF guns. A RF gun with a photocathode can be used to generate a bunch train for a Free Electron Laser (FEL), a RF gun with a thermionic cathode can be used for injection into a storage ring. Both injectors will operate with the same regular part of the linear accelerator, consisting of 100-120 identical sections. The purposed transverse emittance in the main storage ring will be 50–100 pm.rad. The development of a general linear accelerator scheme in order to minimize the beam energy spread and the output transverse emittance, the optimization of the geometric and electrodynamics parameters of the accelerating structures, and the beam dynamics analysis in this linear accelerator will be discussed in the article. The beam dynamics simulation was performed using the BEAMDULAC code developed at the Department of Electrophysical Facilities of the National Research Nuclear University MEPhI.

Work on the conceptual design of a dedicated fourth-generation fourth-generation Specialized Synchrotron Radiation Source (SSRS-4) is in progress at the Kurchatov Institute, Moscow. The project is being developed in collaboration with the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. In this paper, the initial results of our work on this project are reported, major directions of current research are presented, and possible areas of application of the SSRS-4 are outlined. The key element of the currently discussed design is a 6-GeV storage synchrotron with an orbit length of ~1300 m and the magnetic lattice that should provide a horizontal transverse emission of 70–100 pm rad. Further optimization may allow for reducing the emittance to 20–40 pm rad. Of the injection schemes under discussion, one features a full-scale booster synchrotron deployed in the same tunnel as the main storage ring, and the second is a topup linac. The latter can also be used as an electron-beam driver for a free-electron laser.