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2019
P18-2019-61 (2.411.062)
Kabylova A. et al.
Mosses as bioindicators of air pollution by heavy metals and other toxic elements in Central Kazakhstan

Instrumental neutron activation analysis in combination with the moss-biomonitoring technique was used for assessment of air pollution in the Central Kazakhstan. Contents of 39 major and trace elements were determined in the moss samples. GIS technologies was used to construct distributions maps of heavy metals and other toxic elements over the investigated territory.

P13-2019-60 (344.584)
Turek M. et al.
Thermodesorption of Argon Implanted in Germanium

Thermal desorption spectroscopy (TDS) measurements of Ar implanted in germanium samples are reported. The Ar implantation energies were 100 and 150 keV while the fluence was 2 · 1016 ñì-2. A sudden release of Ar at the temperatures 790–840 K was observed as sharp peaks of the thermodesorption spectrum. These peaks are probably related to the gas release from cavities in the germanium structure. Desorption activation energy of Ar was found using the Redhead analysis of the Ar peak shift. These values are much larger than the values obtained for thermodesorption of He implanted in germanium.

P1-2019-58 (173.273)
Komarov V. I. et al.
Centrality Criteria of the Inelastic Nucleon—Nucleon Collisions

A process of inelastic nucleon—nucleon collisions with the impact parameter less than a radius of the nucleon quark core is considered. The criteria for selection of such collisions from a full array of the nucleon—nucleon interactions are suggested.

P4-2019-53 (222.439)
Pupyshev V. V.
Two-Dimensional Low-Energy Scattering of a Quantum Particle in the Combined Field of the Coulomb and Power Potentials

We study the two-dimensional scattering of a quantum particle by the force center acting on it through a superposition of the Coulomb and power potential V0 rβ with the exponent β ∈ (1,2). For this scattering, we found explicit low-energy asymptotics of all partial phase-shifts and amplitudes.

P6-2019-48 (226.260)
Norseev Yu. V.
Extrapolational Estimations of Physical-Chemical Properties of Nihonium, Tennessine and Oganesson

The method of comparing calculations is a correlational relation, connecting some properties with other ones in every group of analogical elements. Linear relation between logarithms of retention indexes of organic haloderivatives with one and the same substitutes and their different physical-chemical properties allowed determining extrapolationally boiling and melting point temperatures, heats of vaporization, refraction, carbon-astatine binding energy and dipole moments. Some properties of elemental astatine were determined. The method of comparing calculations can be used for estimating some physical-chemical properties of nihonium, tennessine and oganesson. It is shown in the figures that linear dependence of some properties on other ones is observed in groups of these elements. Averaged values of their physical-chemical properties obtained because of building more than three relations are given in the tables for these elements.

E9-2019-46 (335.266)
Amirkhanov I. V., Kiyan I. N., Sulikowski J.
Automated Control System (ACS) for Smith—Garren (SG) Curves Measurement

The Smith–Garren (SG) curve is dependence of beam current on the main coil's current for different radii in an isochronous cyclotron. The SG curves are used for calculation of phase motion of accelerated particles in absolute and relative values followed by calculation of phase-energy integral. The results of beam dynamics calculations are used for correction of mean magnetic field to the isochronous one with accuracy better than ±3 G followed by detection of an optimal value of the main coil's current, and for calculation of extraction efficiency of accelerated beam.

P13-2019-43 (1.636.710)
Shakhov A. V. et al.
Possibilities of Using CdZnTe and ÑeBr3 Crystals for Measuring Photon Radiation in a Wide Range of Energy

The new semiconductor detectors, which, based on CdZnTe crystals and ÑeBr3 scintillator, are presented in this work. The spectroscopic setup for testing measurements was created, which consists of CdZnTe, ÑeBr3, and Si (measuring α and γ) detectors. The main characteristics of these detectors including enegy resolution FWHM/Eγ (keV) and efficiency ε(%) were investigated and determined. Moreover, we have checked the possibility of registration in a wide range of energy. The α–γ and γ–γ coincidence measurements were carried out using these detectors. The results could be used to study the mechanisms of nuclear reactions and the properties of reaction products.

P13-2019-42 (338.920)
Pepelyshev Yu. N., Popov A. K., Sumkhuu D.
Model Dynamics of the IBR-2M Pulsed Reactor with Temperature and Power Fast Feedback Effects

The earlier established model of dynamics of the IBR-2M pulsed reactor of periodic operation includes feedback, which, due to the complexity of the description of processes in the core, was presented in a purely mathematical, but not physical way. The paper considers a dynamics model with a dedicated temperature feedback formed by the average temperatures of the fuel and coolant. It is shown that in this case the feedback reactivity cannot be described only by these components. Therefore, power feedback (the dependence of feedback reactivity on power) was also introduced in the model. The model uses discrete transfer functions that reflect the dynamics of pulsed processes in the reactor. Feedback parameters were estimated experimentally. The model can be used to describe changes in the energy of pulses in a wide dynamic range.

E2-2019-41 (86.225)
Shahrbaf M. et al.
First-Order Phase Transition from Hypernuclear Matter to Deconfined Quark Matter Obeying New Constraints from Compact Star Observations

We reconsider the problem of the «hyperon puzzle» and its suggested solution by quark deconfinement within the two-phase approach where the hypernuclear equation of state is obtained from the lowest-order constrained variational method and a rigid quark matter equation of state based on the color superconducting nonlocal Nambu—Jona—Lasinio model with constant coefficients (model A) and with density-dependent coefficients (model B). With model B we introduce for the first time an equation of state of hybrid stars with an intermediate hypernuclear phase between the nuclear and the color superconducting quark matter phases, for which the maximum mass of compact stars reaches 2.2 M⊙ in accordance with the latest observations for PSR J0740 + 6620. We discuss phase transition solutions in symmetric matter with possible applications in future energy scan programs in heavy-ion collisions at CERN, RHIC, NICA and FAIR.

D1-2019-40 (476.541)
Meshkov I. N.
Luminosity of an Ion Collider

A formula is obtained for the luminosity of a collider at the collision of two beams that differ, generally speaking, by their parameters («asymmetric colliders»). The formula is valid for counterpropagating and merging beams with coincident longitudinal axes. Three special cases of the formula are considered: collision of two identical axially symmetric bunched beams, collision of a bunch with a coasting beam, and collision of two coasting beams. Collision of intersecting beams is briefly considered, and the method for calculating their luminosity is formulated. The synchronization problem is considered for collisions of asymmetric beams. A method is presented for optimizing parameters of a cyclic collider by minimizing betatron frequency shifts caused by the action of the space charge of the beams. Numerical examples of luminosity calculations for several types of asymmetric colliders are given.

P9-2019-35 (309.270)
Vasilishin B. V. et al.
The System of Cycle Setting for Nuclotron Booster

The main and two additional currents of the magnetic system of the Nuclotron booster are controlled by three sets of «+» and «–» series of pulses, causing an increase or decrease in the corresponding current by the amount of «quantum» of the current, the value of which is taken to be 0.01 A. In addition, to control the main current, the sequences of «+» and «–» series describing the derivative of the main current I'0 with the value of «quantum» equal to 0.04 A/s are also required. The peculiarity of used power supplies is that they are controlled directly by series pulses, and not by analog signals obtained from them. The control of software, equipment and exchange with the database is performed in the standard of TANGO system.

E1-2019-31 (345.175)
Terekhin A. A. et al.
The Differential Cross Section in Deuteron—Proton Elastic Scattering at 500, 750 and 900 MeV/Nucleon

The results on the differential cross section of dp elastic scattering obtained at the Internal Target Station at the Nuclotron of JINR at energies of 500, 750 and 900 MeV/nucleon are presented. The measurements have been performed using an unpolarized deuteron beam and a polyethylene foil target. The data have been obtained in the angular range of 70°–120° in the cms. The angular dependences of the data from the present experiment are compared with the world experimental data obtained at similar energies as well as with the theoretical calculations performed within the relativistic multiple scattering theory. The behavior of the differential cross section at the fixed scattering angles covering the total cms energy region of √s = 3.1 – 3.42 GeV is in qualitative agreement with the s-power-law dependence.

P2-2019-25 (188.828)
Tagirov E. A.
On Selected Works of N. A. Chernikov. Memorial Essay Dedicated to the 90th Anniversary of the Birth of Professor N. A. Chernikov

The essay reports on two cycles of works of N. A. Chernikov in the 1960s, which received great recognition in the international community of theoretical physicists and remain relevant to modern times. The first part of the essay describes N. A. Chernikov's generalization of the Boltzmann kinetic theory to the general theory of relativity, including construction of the fundamental equation, which in recent decades was called the Boltzmann–Chernikov equation.
In the second part, an almost adventure story is told about the discovery of a general-relativistic equation for a scalar field, which later became known as the equation conformally coupled with gravity. There is a fundamental difference of the quantum approach of Chernikov and the present author (1967–1968) for the general case of a field with a non-zero mass in space-time of arbitrary dimensionality from the classical consideration by R. Penrose (1964), the particular case of massless field based on conformal covariance of the latter. Nevertheless, his classical result has been a decisive hint for the quantum case with a non-zero mass and an arbitrary dimension of space-time. It is noted that it is the general equation with conformal coupling obtained by the field quantization that does satisfy the equivalence principle.


P13-2019-24 (435.323)
Pepelyshev Yu. N., Popov A. K., Sumkhuu D.
The Kinetics of the Pulsed Booster with a Proton Injector

The kinetics of the pulsed booster as an advanced high-flux pulsed neutron source, which is foreseen to replace the IBR-2M pulsed reactor after an exhaust of its service life, is considered. As a booster, a subcritical multiplying assembly with a reactivity modulator, which amplifies neutron pulses generated on a non-multiplying target as a result of the injection of accelerator protons into it, is described. The parameters of neutron pulses of the assembly with a frequency of 30 Hz at various values of the effective lifetime of prompt neutrons and effective multiplication factor of assembly (0.95 and 0.98) are calculated. These calculations allow one to choose the optimal variant of the parameters of the modulator of reactivity, the subcritical rate, the effective lifetime of the prompt neutrons of the assembly, etc.

E1-2019-21 (141.704)
Baatar Ts. et al.
Cumulative Proton Production in π + C Interactions at 40 GeV/ c and the Uncertainty Principle

We study the cumulative proton production in π + C interactions at 40 GeV/c. Cumulative protons, in comparison with the noncumulative ones, are produced at large values of the variable nc (nc > 1.0) and in this region the energy of cumulative protons also increases. The experimental values of the cumulative proton energies are compared with the estimations obtained by the formula of the uncertainty principle. It has been shown that the energy of cumulative protons obtained by using the formula of the uncertainty principle is in agreement with the experimental results to an accuracy of less than ∼ 10.

P16-2019-16 (329.957)
Mokrov Yu. V., Morozova S. V.
The Correction of Albedo Dosimeters DVGN-01 Readout at the Neutron Generator EG-5 with the Help of a Spherical Albedo System

The results of readout correction for albedo dosimeters DVGN-01 using a spherical albedo system are presented. The measurements were carried out behind the neutron generator EG-5. On the basis of the presented results, the correction coefficients were recommended for individual radiation control at the neutron generator.

E6-2019-11 (406.390)
MarinovG. et al.
Modified Chromatographic Separation of a Sum of Spallation Lanthanides

The elements of the lanthanide (Ln) row being in the transitional region of nuclear deformation are of great scientific interest. Since the 1960s, the Ln series has been researched and methods for the separation of these elements have been developed. One of the most successful separation methods has been developed by N. A. Lebedev at the Joint Institute for Nuclear Research (JINR) for the accelerated separation of spallation lanthanides from irradiated Ta target at 660 MeV. The products from such targets are used in scientific research, medical therapy and diagnostics. Nowadays, the need is for Ln radioisotopes with longer half-lives. Thus, the method developed by N. A. Lebedev is reevaluated and modified: the UTEVA column is added, facilitating the purification from Hf and Zr isotopes used in different scientific research. The further separation of individual Ln is carried out with the use of Aminex A6 resin and a mixture (MIX-α-HIB) of ammonium α-hydroxyisobutirate (NH4-α-HIB) with α-hydroxyisobutiric acid (α-HIBA) (with regulated pH). The obtained elementally pure fractions were further used in γγ-TDPAC measurement of ferrites and tungstates.

P11-2019-9 (86.985)
Amirkhanov I. V., Sarker N. R., Sarkhadov I.
About One Method of Approximate-Analytical Solution of the Quantum-Mechanical Three-Body Problem

A method is proposed for investigating the solutions of a single quantum-mechanical three-body problem. The boundary value problem for a system of two particles moving in the potential field of the third particle is studied. The interaction potentials between the particles are chosen to be quadratically growing. In this case, the two-body problem has an exact solution. The solution of the original three-body problem is represented as an expansion in the solutions of the two-body problem. The coefficients of the expansion yield a homogeneous linear matrix equation. Equating the determinant of this equation to zero, we find the eigenvalues of the original problem and the coefficients of the expansion. Since the elements of the matrix of algebraic equations with solutions of the two-body problem are calculated analytically, the eigenvalues of the three-body problem depend explicitly on the parameters of the potentials. Changing these parameters in an arbitrary way, we can obtain the desired spectra, i.e., one can control the eigenvalues of the original problem.

P3-2019-8 (239.209)
Rzyanin M. V., Shabalin E. P.
On the Issue of Stability and Safety of the Superbooster «Neptun»

Highly intense pulsed neutron source which should replace the pulsed reactor IBR-2M currently in operation after its wear-out, can be made as superbooster, that is a powerful breeder of neutrons produced in accelerating proton target. Usually, superbooster is considered to be a safe and reliable nuclear facility. However, as indicated in the paper, powerful superbooster can be less stable in operation than pulsed reactor. Therefore, problems of its safety call for close study.

E9-2019-4 (170.120)
Sumbaev A. P., Barnyakov A. Yu., Levichev A. E.
On the Limits for the Accelerated Beam Current in the LUE-200 Linac of the IREN Fañility

The beam current loading of the accelerating fields is discussed for the linear accelerator LUE-200 of the IREN facility (a neutron source at the Frank Laboratory of Neutron Physics, JINR). The LUE-200 electron linac consists of two disk loaded traveling wave accelerating structures with the operating frequency of 2856 MHz and SLED-type power compression system. The limits for the accelerated beam current are defined for different pulse durations of the beam current and RF power. The calculated results are discussed and compared with the measurements.

E9-2019-2 (585.768)
Karamyshev O. et al.
Conceptual Design of the SC230 Superconducting Cyclotron for Proton Therapy

Physical design of the compact superconducting cyclotron SC230 has been performed. The cyclotron will deliver up to 230 MeV beam for proton therapy and medico-biological research. We have performed simulations of magnetic and accelerating systems of the SC230 cyclotron and specified the main parameters of the accelerator. Possible schema of the extraction system and preliminary results of beam dynamics simulations are presented. Codes and methods used for the beam tracking are shortly described.

2019-1 (2.051.736)
Brief Review of Topmost Scientific Results Obtained in 2018 at the Joint Institute for Nuclear Research



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