BM@N (Baryonic Matter at Nuclotron) is the first working experiment performed on the NICA accelerating complex. It is a fixed target experiment. To this moment there have been seven runs of the experiment, most of which are technical. In 2018 the first run of the experimental facility with physics data collection took place. One of the prerequisites for physics analysis of experimental data is the existence of the primary vertex position estimation. Current report describes the proposed algorithm to reconstruct the primary vertex using the virtual planes method. The results of this algorithm for different targets, beams and trigger conditions are presented. The sensitivity of presented method is considered.

A nearly self-consistent quasi-equilibrium stellar halo model is presented for the Fornax dwarf spheroidal satellite galaxy, associated with the Milky Way. Such satellite galaxies are dominated by dark matter and have almost no gas in the system. They are excellent objects for N-body modeling that takes into account visible and dark matter halo components. Each one of the N particles in our model follows its own orbital motion within the self-consistent gravitational potential, which is itself generated by all these particles. A source code is applied that is embedded in the AGAMA framework and is based on the Schwarzschild calculation of orbits. To construct the components, the initial guess is to use a stellar–dark matter model of the Fornax galaxy, which is based on the hydrodynamic axisymmetric Jeans equations, taking into account the velocity anisotropy parameter. The first studies of the galaxy are bounded by the hydrodynamic approaches based on the Jeans equations. However, the free paths of dark matter particles are huge; hence, the applicability of the hydrodynamic approximation is doubtful. Further studies of the dwarf spheroidal galaxies associated with the Milky Way assume non-self-consistent (stars moving in the dark matter gravitational field) models of the objects based on distribution functions depending on the action integrals. Self-consistent modeling is performed only for the spherically symmetric approximation. Our model is self-consistent and axially symmetric; i.e., it takes into account the prolateness of the dark halo. On the basis of the available density distribution of the components, we obtain the model velocity dispersion profile of the galaxy’s stellar component. The profile is consistent with the observational data for the stellar component. Thus, the given density distribution for the dark halo can be used to predict the dark matter annihilation signal. Calculations are also performed for the numerical evolution of the resulting model in a self-consistent N-body gravitational field. The model is shown to be sufficiently stable over several dozen dynamical times.

Heavy mesons and doubly heavy baryons with the dynamic properties governed by the light quark motion relative to the fixed center of forces are studied within the Heavy Quark Effective Theory. The distribution amplitudes of the hadrons in question are compared, model functions of these amplitudes for the doubly heavy baryons are introduced, and their scale dependence is investigated.

For normally incident on optimal converter targets “needle-like” “instantaneous” beams of electrons with the kinetic energies E⁻ = 55, 220, 1000 MeV, distributions of produced positrons with different kinetic energies at the converter outputs were model-calculated for linear transversal and angular deviations from the axis of electron beams and for time. The calculation results are compared with the available literature data and the requirements of experiments.

The paper presents the results of calculations of the sampling fluctuations in Pb–LAr electromagnetic sandwich calorimeters. The GEANT4 package was used to generate showers initiated by electrons with energies E₀ from 20 to 500 GeV. It is shown that the dependence of the sampling fluctuations on E₀ and the thickness of the lead absorber x can be described by the formula kx^b/√E₀. The exponent b weakly depends on the LAr gap width d and is close to 2/3 and k = (0.1985 ± 3) – (0.0363 ± 2)lnd[mm].

The paper presents the results of experiments carried out during the preparation of the HIPr accelerator for irradiation of reactor structural materials specimens in order to simulate radiation-induced defects. A method for measuring the beam profile using a CCD camera is presented. The results of time-of-flight measurements of Fe2+ ion beam based on HIPr accelerator with an RFQ accelerating structure are presented.

In this paper, we describe the project of a photon source with energies up to 2500 MeV at the SKIF synchrotron facility (under construction in Novosibirsk). It is intended for experiments on photonuclear reactions, nonlinear QED, EM detector calibration and other applications. A polarized photon beam with a flux of 10⁶ – 10⁸ Hz (in full spectrum) is produced using Compton backscattering (or inverse scattering) of IR, visible, and UV laser radiation, as well as the UV band of its own synchrotron radiation, on the SKIF electron beam (15 kHz). Spectrum monochromatization with collimators or/and tagging system by recoil electrons is possible. The discrepancy between experimental and theoretical photofission cross sections of actinide nuclei in a photon energy range of hundreds of MeV has been known since the 1980s, so it is proposed to study these cross sections in the first series of experiments.

The strong absorbing properties of suspensions with nanoparticles and the possibility of organizing boiling in volume make this process very promising for the creation of solar desalination plants on its basis. The paper presents an experimental study of the boiling of a suspension based on water with the addition of sea salt, carried out on a laboratory system with the condensate recycling. Three types of particles were used in the study: multilayer carbon nanotubes with an average diameter of ~60 nm and a length of ~5 μm, 110-nm particles of iron oxide Fe₃O₄, and a commercial modifier of industrial composition based on carbon nanotubes. Particle mass concentrations varied from 0.5 to 10%. To study the influence of sea salt on the boiling process of nanofluids, similar experiments were carried out for nanofluids based on distilled water. Comparing the results of an experimental study for nanofluids based on distilled and salt water, it was found that the addition of sea salt can lead to both an increase in the steam generation rate and a decrease depending on the type of nanoparticles and their concentration. The presence of sea salt in the nanotube-based suspension increases the steam flow rate by 7.5%, while for iron oxide particles, the change in the steam flow rate varies from –0.5 to 12%, depending on the particle concentration. For suspensions based on a commercial modifier, the change in the rate of steam generation in the presence of salt also depends on the particle fraction and varies from –5.2 to 7%. The optimal composition of the suspension, which provides the highest rate of steam generation, was determined by comparing the obtained experimental data with the experiment on boiling seawater in a blackened steam generator. Adding 5% carbon nanotubes to salt water results in the largest increase in steam generation rate by 23% compared to boiling salt water in a blackened flask. The results of this work can become the basis for the development of solar desalination plants based on fine dispersions.