Natural Sci. Rev. 2 100405 (2025) DOI: 10.54546/NaturalSciRev.100405
Natural Sci. Rev. 2 100404 (2025) DOI: 10.54546/NaturalSciRev.100404
Progress in the design and modeling methods of the MSC230 superconducting cyclotron for proton therapy
With the emergence of the FLASH irradiation method in proton therapy, the need for high-current accelerators has grown significantly. Addressing this demand, the Joint Institute for Nuclear Research (JINR) has initiated the development of the MSC230, a compact isochronous cyclotron designed to produce high-intensity proton beams at 230 MeV for advanced biomedical research. Currently, the technical design of the cyclotron is in progress at D. V. Efremov Institute of Electrophysical Apparatus. Modifications during this phase often necessitate additional calculations, resulting in updates to the magnetic field configuration and beam dynamics. This article details the design methodologies and computational tools employed in the MSC230 project.
Natural Sci. Rev. 2 100403 (2025) DOI: 10.54546/NaturalSciRev.100403
Decays τ → ππηντ and τ → πηηντ in the extended Nambu–Jona-Lasinio model
In the framework of the extended Nambu–Jona-Lasinio model, the processes τ → ππη ( η′ ) ν τ and τ → πηη ( η ′) ν τ are considered taking into account mesons in the ground and first radially excited intermediate states. It is shown that in the processes τ → ππη ( η′ ) ν τ the vector channel is dominant, and in the processes τ → πηη ( η′ ) ν τ the main contribution is given by the axial-vector channel. The scalar meson a 0 plays a dominant role in processes with two η mesons in the final state. The significance of the relative phase between the ground and first radially excited states for these processes is shown. The obtained results for the τ → ππην τ process are in satisfactory agreement with the recent experimental data from BaBar and CMD-3, which differ from the averaged values given in the PDG tables.
Natural Sci. Rev. 2 100402 (2025) DOI: 10.54546/NaturalSciRev.100402
Shadow in the Galactic Center: Theoretical Concept – Prediction – Realization
General Relativity (GR) was created in November 1915, and since its creation this theory has undergone many tests. The first realistic cosmological models were proposed in the works of Friedmann, written in the 1920s. For a long time, Friedmann’s cosmological works were actually banned in the Soviet Union due to philosophical reasons, since the models where the birth and evolution of the Universe occurs were considered ideologically unacceptable. Due to great achievements in relativity and cosmology and due to increasing interest in these branches of science in the last decades, we recall the development of relativistic astrophysics and contribution of Russian researchers to these studies. Since one of the world leaders in physical cosmology A. A. Friedmann passed away in September 1925, it is reasonable to outline the main achievements of physical cosmology over the past 100 years. We also discuss observational and theoretical achievements in confirmations of relativistic observational predictions for black holes, including the closest supermassive black hole in our Galactic Center. We outline the evolution of black hole shadow from the purely theoretical concept to observable quantities for supermassive black holes in Sgr A* and M87*.
Natural Sci. Rev. 2 100401 (2025) DOI: 10.54546/NaturalSciRev.100401
