bluuebunny/crossref_metadata_2025 huggingface dataset:
Plasma-chemical processes in the mixtures “metal-organic compound” and “metal-inorganic salt” initiated by pulse radiation of gyrotron
Authors: Akhmadullina N.S. , Skvortsova N.N. , Obraztsova E.A. , Stepakhin V.D. , Konchekov E.M. , Kargin Yu.F. , Konovalov A.A. , Shishilov O.N.
Published: December 2020

Plasma-chemical processes in the mixtures of metal+organic compound and metal+inorganic salt under treatment by microwave pulses are described. The microwave pulses were generated by high-power gyrotron (frequency 75 GHz, power up to 550 kW, pulse duration from 0.1 to 15 ms). Al + melamine (1:1, 2:1 and 3:1 by molar) and Al + Al2O3 + NH4Cl (1:2:2 and 1:2:4 by molar) were treated in air with microwave pulses with power of 150-K350 kW and duration of 2^8 ms. It was found that the discharge can be easily initiated for both mixtures at minimal pulse duration of 2 ms. For Al + melamine mixture the energy threshold for the discharge depends linearly on the mass content of Al and does not exceed 1.0 kJ/g. For Al + Al2O3 + NH4Cl the threshold is also below 1.0 kJ/g. The products of treatment of Al + melamine contain mainly starting materials and no nitride phases, in case of Al + Al2O3 + NH4Cl some traces of Al11O15N were identified.
Application of the Green Function Method for Calculating the Spatial Distribution of Electrons in the Finite System
Authors: Yu Igashov S , Blinnikov S I , Kuratov S E , Shidlovski D S
Published: December 2020

The paper presents a numerical implementation of the Green’s function method for calculating the spatial distribution of the macroscopic number of free electrons in a finite system. The obtained results are compared with the results obtained by direct summation of the wave functions. The quantitative coincidence is demonstrated.
On numerical modeling of natural convection based on the OpenFOAM solver
Authors: Kozlov V.K. , Chmykhov M.A.
Published: December 2020

This work considers numerical modelling of natural incompressible convection problems in the gravity field in the Boussinesq approximation using OpenFOAM. A mathematical model of natural convection in the gravity field, using Boussinesq approximation, was considered. The built-in solver was identified and modified. The exact solution, theoretical data and experiment were used to verify the solver. A numerical study of natural convection in a horizontal liquid layer was performed. Natural convection in a fluid layer between coaxial cylinders was considered.
Numerical modeling of the switching processes in the second generation HTS tapes under the electric pulses impact
Authors: Anischenko I V , Pokrovskii S V , Rudnev I A
Published: December 2020

This paper presents the results of complex multiphysical modeling of nonequilibrium states arising in high-temperature superconducting composites under the pulsed current impact. The time dependences of the voltage on the superconducting tape under the influence of current pulses for the pulse amplitudes from 0.6 to 2 values of the critical current of the tape are obtained. Two linear modes of the sample voltage behavior during the electric current load are distinguished. A stable HTS sample switching at the current pulse amplitudes less than 1.7 Jc
and the development of irreversible dynamic thermal instability for the higher currents are shown. The simulation was performed by the finite element method in the Comsol Multiphysics software package.
Taking into account Abrikosov vortices in numerical solution of Ginzburg-Landau equations
Authors: Kartsev P F
Published: December 2020

The method is described to take into account the Abrikosov vortices in numerical study of superconducting quantum state in the framework of Ginzburg-Landau equations. The main idea is based on explicit extraction of the solution component related to the vortices. Such approach can be especially useful to study problems with fixed vortex positions.
Tribological characteristics of hard Zr-Si-B coatings in sliding friction and cycling impact loading terms
Authors: Kiryukhantsev-Korneev Ph V , Sytchenko A D
Published: December 2020

Coatings were obtained by magnetron sputtering of a ZrSiB target onto WC-6%Co substrates. Samples were studied in terms of their structure, friction coefficient, wear- and impact loading resistance. The Zr-Si-B coating contained the hexagonal ZrB2phase. Coating deposition reduces the friction coefficient of the substrate by 10% and increases the resistance to impact loads by 25-50%.
Thermal energy converters based on granular silicon
Authors: Abdurakhmanov B M , Adilov M M , Sh Kurbanov M
Published: December 2020

The use of granular silicon (GS) makes it possible to create a system like “electronic crystal-phonon glass” and reduce the cost of materials. With GS from silicon slurry, it is possible to obtain values of the Zeebeck coefficient of ∼500 μV/deg and to reduce the thermal conductivity by 7-9 times as compared to single-crystal silicon. The GS high conductivity is proposed to be achieved by resonant tunneling of current carriers through a nanosized SiO2 layer covering the GS particles.
Formation of structure of TiNiCu alloys with high copper content upon producing by planar flow casting
Authors: Shelyakov A V , Sevryukov O N , Sitnikov N N , Borodako K A , Khabibullina I A
Published: December 2020

The rapidly quenched alloys of the quasibinary intermetallic TiNi-TiCu system with a high copper content (more than 25 at.%) are of great interest as shape memory materials due to the possibility of a significant decrease in the temperature and deformation hysteresis in comparison with the binary TiNi alloy. To obtain alloys with a copper content of 25 to 40 at.%, the planar flow casting technique was used. The alloys were fabricated at a melt cooling rate of about 106 K/s in the form of ribbons 30-50 μm thick and wide in the range from 7 to 20 mm. The study of the structure of the alloys was carried out using X-ray diffraction analysis, scanning and transmission electron microscopy. It was shown that from the ribbon side, contacting the quenching wheel, all alloys are amorphous, while on the non-contact side of the ribbons of alloys with 25 and 30 at.% Cu, a thin surface crystalline layer with a B2 structure is observed. Using energy dispersive X-ray spectroscopy, it was found that the content of the alloy components in the amorphous and crystalline phases coincides.
Investigation of thermal-structural characteristics at two-way shape memory effect of rapid quenched laminated amorphous-crystalline ribbons of Ti50Ni25Cu25 alloy
Authors: Sitnikov N N , Sivtsova G V , Shelyakov A V , Khabibullina I A
Published: December 2020

The work is devoted to the study of processes of structural changes leading to the realization of the two-way shape memory effect (TWSME) in the rapid quenched amorphous-crystalline alloy Ti50Ni25Cu25. The object of the study was a rapid quenched laminated amorphous-crystalline Ti50Ni25Cu25 alloy ribbon with a thickness of about 39 um and with a thickness of surface crystal layer about 10 μm was present on the non-contact side relative to the quenching wheel. In the ribbon under study, without any additional heat treatments the TWSME with bending deformation from a rectilinear shape during heating and cooling in the range of martensitic transformation is manifested. The samples were characterized by means: scanning and transmission electron microscopy; X-ray diffraction analysis; differential scanning calorimetry; measuring the characteristics of the crystalline layer during the implementation of TWSME and the temperature dependence of the form change. It was shown that the formation of a laminated amorphous-crystalline composite occurs due to the martensitic transformation of B2∼B19 in the crystal layer and the accompanying TWSME as a result of which the crystal layer is reduced.
Approaches for improving the quality of particle size distribution reconstructions from small-angle scattering data
Authors: Volkov V V , Kryukova A E , Konarev P V
Published: December 2020

Using a series of two- and three-component model data of small-angle scattering from systems of polydisperse spherical particles, the possibility of determination of the particle size distribution function by regularization methods, a direct histogram search, and as a superposition of smooth analytical functions has been investigated. The advantages and disadvantages of these approaches are considered. It is shown that their combined use allows one to improve the quality particle size distribution and find acceptable solutions even in the case of significant data noise. The choice of the appropriate minimization algorithms is also an important factor for efficient data analysis. A number of iterative algorithms based on the gradient minimization method, the simulated annealing method, their combination, and the Nelder-Mead method is tested and their efficiency is compared for the small-angle scattering data of a silicasol solution.
Preparation and some properties of crystal Rb2NiCl4-2H2O
Authors: Zainullin O B , Voloshin A E , Komornikov V A , Rudneva E B , Manomenova V I , Timakov I S , Kozlova N N
Published: December 2020

The paper presents the results of studies on the growth of Rb2NiC14-2H2Ocrystals and the study of their properties. The conditions for the reproducible production of Rb2NiC14-2H2Osingle crystals by the method of controlled decrease of solubility are determined. The optical and thermal properties of crystals obtained in this way were studied.
Local electrochemical deposition of thorium-229 targets and excitation of isomeric state by electron beam
Authors: Borisyuk P.V. , Vasilyev O.S. , Lebedinskii Yu.Yu.
Published: December 2020

The results of the study of local formation of thin-film coatings based on thorium oxide on SiO2/Si(111) surfaces by electrochemical deposition. It is shown that as a result of electrochemical deposition of thorium atoms from an acetone solution of Th(NO3)4 with the presence of water on the silicon surface, local formation of thorium compounds occurs. Chemical analysis of the composition of the samples obtained by XPS showed the presence of compounds based on thorium, silicon, oxygen and carbon. It is shown that annealing for 6 hours at 600? C in the atmosphere leads to the departure of carbon, and the formed film consists only of thorium and oxygen. It is shown that such a system can be promising for further studies of the nuclear low-lying isomer transition in the 229Th isotope under electron beam irradiation. The method of excitation of isomeric thorium-229 nuclei by irradiation of a solid-state target based on thorium silicate with an electron beam is considered. The process of generating secondary electrons with a significant increase in the multiplication coefficient for electrons with energies in the range from 1 keV to 25 keV is considered. The values of the output function of isomeric nuclei and the excitation cross section of an isomeric transition in inelastic scattering are obtained on the basis of numerical modeling and theoretical estimation.
Features of Quasi-frozen Spin Concept of Storage Ring for Searching for Electric Dipole Moment of Deuteron
Authors: Senichev Y. , Aksentyev A.
Published: December 2020

One of the possible arguments for violating CP invariance is the existence of non-vanishing electric dipole moments (EDM) of elementary particles. To search for EDM, it was proposed to create a special storage ring [1], which can implement the “frozen spin” mode. An advantage of the “quasi-frozen spin” [2] concept developed by us is the ability to adapt existing storage rings to search for the deuteron EDM, in particular the accelerator complex NICA in JINR (Dubna).
Pyrometric investigation of nanoparticles condensation process in gaseous and superfluid helium
Authors: Stepanov M E , Kulish M I , Karabulin A V , Matyushenko V I
Published: December 2020

The work is devoted to the study of thermal radiation accompanying the condensation of products of pulsed laser ablation of a tungsten target in vacuum, superfluid and gaseous helium. Pyrometric measurements have shown that the radiation characteristics depend on the medium. The obtained data imply that the sources of radiation in vacuum and gas are predominantly submicron particles, while in superfluid helium (He II) they are nanometer particles. These conclusions have been confirmed by electron microscopy data.
Investigation of the mechanism of solar flare and acceleration of solar cosmic rays in real conditions of the solar corona
Authors: Podgorny I M , Podgorny A I , Borisenko A V , Vashenyuk E V , Balabin Yu. V. , Meshalkina N. S. , Gvozdevskiy B. B.
Published: December 2020

The generation of solar cosmic rays occurs during explosive energy release in a solar flare, so in order to understand this phenomenon it is necessary to study both the mechanism of the solar flare and the process of particle acceleration by the generated electric field. During a solar flare in the solar corona above the active region (AR), the energy stored in the magnetic field of the current sheet is released. Using the results of numerical simulation and observations, I.M. Podgorny proposed an electrodynamic model of a solar flare, explaining its main observational manifestations, in particular, the appearance of X-ray emission on the surface of the Sun. The acceleration of protons occurs along a singular line of the magnetic field of the current sheet by the electric field E = -V×B/c. To obtain accurate results it is necessary to carry out MHD simulation in the real scale of time, which is only be done using parallel calculations. The parallelization of the program PERESVET carried out using graphics card (GPU), the calculations were accelerated by ~ 120 times. As a result of optimization of the approximation of the boundary conditions of free exit at the non-photospheric boundary, instability near the boundary was stabilized. The first results of MHD simulation in the real scale of time above the AR 10365 showed the appearance of a plasma flow near singular X-type lines, which have to cause to the formation of a current sheet.
Precision measurements of cosmic ray electron and positron spectra above 50 MeV with the PAMELA magnetic spectrometer
Authors: Mikhailov V V , Aleksandrin S Y , Koldobskiy S A , Boezio M , Munini R , Ngobeni M D , Aslam O P M , Potgieter M S
Published: December 2020

The PAMELA experiment with magnetic spectrometer operated almost ten years on board of the Resurs DK1 satellite. The satellite was launched on 15 June 2006 on polar orbit with an inclination of 70° and an altitude of 350–610 km. The spectrometer continuously measured charged cosmic ray particles in wide energy range from about 50 MeV up to several TeV. In this work the spectra of electrons and positrons averaged over one year were obtained from July of 2006 until January 2016, i.e. from the end of 23th and at the beginning of 24th solar cycle including the period of interplanetary magnetic field polarity reversal. These precise long duration time-dependent measurements of the electron and positron spectra are important to estimate possible contributions of exotic cosmic ray sources such as dark matter annihilation or decay.
Theoretical uncertainties of muon transport calculations for very large volume neutrino telescopes
Authors: Sandrock A , Kokoulin R P , Petrukhin A A
Published: December 2020

Underground cosmic-ray experiments, including very large volume neutrino telescopes, depend on a precise description of the interaction cross sections of muons, which can travel large distances before reaching the detector. High-energy muons lose their energy almost exclusively via four processes: ionization, electron-positron pair production, bremsstrahlung and inelastic interaction with nuclei. At low energies, ionization is the dominant process, while above energies of about a TeV, the three other processes dominate the energy loss. We discuss the uncertainties of the cross sections of the energy loss processes used in the simulation chain of current very large volume neutrino telescopes and review recent theoretical improvements.
Intensity of muon bundles according to the NEVOD-DECOR cosmic ray experiment
Authors: Bogdanov A G , Barbashina N S , Chernov D V , Khokhlov S S , Kindin V V , Kokoulin R P , Kompaniets K G , Mannocchi G , Petrukhin A A , Trinchero G , Shutenko V V , Yashin I I , Yurina E A , Zadeba E A
Published: December 2020

Data of NEVOD-DECOR experiment on investigations of inclined cosmic ray muon bundles for a long time period (May 2012 – May 2020) are presented. Their comparison with the results of calculations based on simulations of extensive air shower hadron and muon components is carried out. The analysis showed that the observed intensity of muon bundles at primary particle energies of about 1018 eV and higher can be compatible with the expectation only under the assumption of an extremely heavy mass composition of cosmic rays. On the contrary, measurements of the depth of the shower maximum in the atmosphere in the experiments using air fluorescence technique, favour a light mass composition of primary cosmic rays at these energies.
Performances of ENDA-INR prototype array
Authors: Shchegolev O , Alekseenko V , Kuleshov D , Levochkin K , Stenkin Yu , Stepanov V
Published: December 2020

Electron Neutron Detector Array (ENDA) is an ambitious project inside the Large High Altitude Air Shower Observatory (LHAASO) in China, Tibet. ENDA is intended to measure simultaneously electronic and hadronic components of the extensive air showers (EAS) over large area of 104 m2. The array will consist of 400 specially developed electron-neutron detectors based on inorganic ZnS(Ag) + B
2
O
3 scintillator compound. The prototype ENDA cluster of 16 electron-neutron detectors has been build in Moscow in the Institute for Nuclear Research of Russian Academy of Sciences and named ENDA-INR. The main goal of the array is to test techniques of simultaneous measurement of extensive air showers and background variations using pulse shape selection. Details of the array and its techniques are presented.
Possibilities of the Tunka-Grande and TAIGA-Muon scintillation arrays with the TAIGA-HiSCORE Cherenkov array joint operation in the research of cosmic and gamma rays
Authors: Ivanova A , Budnev N , Chiavassa A , Dyachok A , Gafarov A , Garmash A , Grebenyuk V , Gress O , Gress T , Grishin O , Grinyuk A , Horns D , Kalmykov N , Kindin V , Kiryuhin S , Kokoulin R , Kompaniets K , Korosteleva E , Kotovschikov I , Kozhin V , Kravchenko E , Krykov A , Kuzmichev L , Lagutin A , Lemeshev Y , Lubsandorzhiev B , Lubsandorzhiev N , Mirgazov R , Mirzoyan R , Monkhoev R , Osipova E , Pakhorukov A , Pan A , Panasyuk M , Pankov L , Petrukhin A , Poleschuk V , Popova E , Porelli A , Postnikov E , Prosin V , Ptuskin V , Pushnin A , Raikin R , Rubtsov G , Rybov E , Sagan Y , Samoliga V , Silaev A , Silaev A , Sidorenkov A , Skurikhin A , Slunecka C , Sokolov A , Suvorkin Y , Sveshnikova L , Tabolenko V , Tanaev A , Tarashansky B , Ternovoy M , Tkachev L , Tluczykont M , Togoo R , Ushakov N , Vaidyanathan A , Volchugov P , Voronin D , Wischnevski R , Zagorodnikov A , Zhurov D , Yashin I
Published: December 2020

The Tunka-Grande scintillation array is part of the TAIGA Gamma Observatory. It is intended for investigation of energy spectrum and mass composition of primary cosmic rays in the energy range 10 PeV–10 EeV and the search for diffuse cosmic gamma rays. The TAIGA-HiSCORE Cherenkov array aims at observing gamma-rays with the energy from 1 TeV. TAIGA-Muon low-threshold scintillation detector array is a network of surface and underground detectors for registration charge particles of EAS. Currently, 3 clusters have been deployed. The first cluster is running in test mode. It is planed that in the future the total area of the TAIGA-Muon will be about 2000 sq. m. and it will search astrophysical gamma-rays in the energy range from 100 TeV together with the Tunka-Grande scintillation array and the Cherenkov experiments of the TAIGA Gamma Observatory. To evaluate the possibility of join operation Tunka-Grande, TAIGA-Muon and TAIGA-HiSCORE, a simulation was performed using the CORSIKA and Geant4 software packages. The status of model-based studies is presented and assessed the prospects for joint operation of the arrays.
Feasibility study to measure the muon bremsstrahlung cross section with the energy loss profile using neutrino telescopes
Authors: Soedingrekso J , Sandrock A , Huennefeld M , Meier M , Rhode W
Published: December 2020

Muons are the dominant event signature for neutrino telescopes like IceCube and they are the main background for neutrino searches. Furthermore, they are used to investigate extended air showers. In both cases, the stochasticity of the muon propagation plays a key role in the data extraction step and an accurate understanding, even of the edge cases, is crucial. The main process driving stochastic losses for TeV scale muons is bremsstrahlung.

In this paper, a feasibility study is presented to measure the cross section of stochastic losses using neutrino-induced muons. The simulation study is based on the propagation of muons using the Monte-Carlo library PROPOSAL. For different reconstruction methods and resolutions, the energy loss distribution for different muon energies is used to estimate the sensitivity to measure the bremsstrahlung cross section. Two further systematic parameters, the detection efficiency, which scales the amount of detected light, and the spectral index are also estimated to analyze their correlation to the estimated bremsstrahlung normalization. The statistics of the simulated dataset correspond to 10 years of up-going muon neutrino data in IceCube.
First detection of gamma-ray sources at TeV energies with the first imaging air Cherenkov telescope of the TAIGA installation
Authors: Postnikov E B , Astapov I I , Bezyazeekov P A , Blank M , Borodin A N , Bruckner M , Budnev N M , Bulan A V , Chiavassa A , Dyachok A N , Gafarov A R , Garmash A Yu , Grebenyuk V M , Gress O A , Gress T I , Grinyuk A A , Grishin O G , Horns D , Ivanova A L , Kalmykov N N , Kindin V V , Kiryuhin S N , Kokoulin R P , Kompaniets K G , Korosteleva E E , Kozhin V A , Kravchenko E A , Kuzmichev L A , Kryukov A P , Lagutin A A , Lavrova M V , Lemeshev Yu , Lubsandorzhiev B K , Lubsandorzhiev N B , Mirgazov R R , Mirzoyan R , Monkhoev R D , Osipova E A , Pakhorukov A L , Pan A , Panasyuk M I , Pankov L V , Petrukhin A A , Poleschuk V A , Popesku M , Popova E G , Porelli A , Prosin V V , Ptuskin V S , Pushnin A A , Raikin R I , Rjabov E , Rubtsov G I , Sagan Y I , Samoliga V S , Sidorenkov A Yu , Silaev A A , Silaev A A , Skurikhin A V , Slunecka M , Sokolov A V , Suvorkin Y , Sveshikova L G , Tabolenko V A , Tanaev A B , Tarashansky B A , Ternovoy M , Tkachev L G , Tluczykont M , Ushakov N , Vaidyanathan A , Volchugov P A , Voronin D , Wischnewski R , Yashin I I , Zagorodnikov A V , Zhurov D P
Published: December 2020

TAIGA array addresses gamma-ray astronomy at energies from a few TeV to several PeV as well as cosmic ray physics from 100 TeV to several EeV. A 1 km2 TAIGA setup will consist of 120 wide-angle detectors of the Cherenkov timing array TAIGA-HiSCORE and three imaging air Cherenkov telescopes with the field of view diameter of 9.6°. In this paper, first experimental results of the first operation stage are presented: signal detection from two gamma-ray sources, the Crab Nebula and Markarian 421, by the first IACT in stand-alone mode. The detected signal is shown to be in agreement with the Monte Carlo expectation. In future, gamma-ray signal will be detected by a larger number of TAIGA telescopes as well as the TAIGA-HiSCORE array, that is, in combined operation mode.
Design of the readout electronics for the fast trigger and time of flight of the GAMMA-400 gamma-ray telescope
Authors: Arkhangelskiy A I , Galper A M , Arkhangelskaja I V , Bakaldin A V , Chasovikov E N , Chernysheva I V , Dalkarov O D , Egorov A E , Gusakov Yu V , Kheymits M D , Leonov A A , Pappe N Yu , Runtso M F , Stozhkov Yu I , Suchkov S I , Topchiev N P , Yurkin Y T
Published: December 2020

The GAMMA-400 gamma-ray telescope is planned for the launch at the end of this decade on the Navigator service platform designed by Lavochkin Association on an elliptical orbit with following initial parameters: an apogee ~300000, a perigee ~500 km, a rotation period ~7 days and inclination of 51.4°. The apparatus is expected to operate more than 5 years, reaching an unprecedented sensitivity for the search of dark matter signatures and the study of the unresolved and so far unidentified gamma-ray sources. An electronics system, which consists of 14 front-end multichannel electronics modules and the main processing unit with a total power consumption of about 400 W (74W for main processing unit), has been developed for providing fast trigger and veto for the data taking to the experiment. The communication between front-end modules, main processing unit and scientific data acquisition system of the gamma-ray telescope is performed via high-speed SPACEWIRE network. To assure the long-term reliability in space environment, a series of critical issues such as the radiation hardness, thermal design, components and board level quality control, warm and cold redundancy are taken into consideration. The main design concepts for the system, measurements setups together with some test results are presented.
Search of x-ray solar activity correlations with 55Fe, 60Co nucleus decay rates
Authors: Bogachev S A , Kharlamov A G , Kishin I A , Kubankin A S , Mayburov S N , Tsekhosh V I
Published: December 2020

Several experimental groups observed temporary modulations of some nuclei strong and weak decay constants, which are of the order of 10−3 and with periods of one year, solar day, i.e. 24 hours and some others. In our experiments the decay rates were measured for 55Fe e-capture and 60Co β-decay during 2012–2020. Altogether, six decay rate dips of the order 10−2 – 10−3 and with duration from 40 to 208 hours were found, they deviate essentially from exponential decay rate fit. It is shown that their occurrence correlate with x-ray solar flares with significant reliability. Besides, two long term deviations of 55Fe decay rate of 62 and 41 days were observed in 2017–2018, it’s argued that they are related to the change of 11 year solar cycle stages.
A concept of the transition radiation detector for a hadron separation in a forward direction of the LHC experiments
Authors: Belyaev N , Cherry M L , Doronin S A , Filippov K , Fusco P , Gargano F , Konovalov S , Loparco F , Mazziotta M N , Mufazalova A , Nechaeva S , Ponomarenko D , Rembser C , Romaniouk A , Savchenko A A , Shulga E , Smirnov S , Smirnov Yu , Spinelli P , Sultanaliyeva L , Teterin P , Tikhomirov V , Vorobev K , Zhukov K
Published: December 2020

Studying of hadron production in forward direction at the LHC energy has a great interest both for understanding of the fundamental QCD processes and also in applied areas such as the description of ultra-high energy cosmic particle interactions. The energies of secondary hadrons in such studies almost reach the maximum energy available at the LHC of ~6 TeV, which corresponds to a Lorentz γ-factor up to 104 and above. The only effective technique able to identify particles in this range is based on the transition radiation detectors (TRD). Prototypes of such kind of detector were built and tested at the CERN SPS accelerator. Some experimental results obtained in these tests are briefly presented here and compared with Monte Carlo (MC) simulations. MC model demonstrates a good agreement with the experiment. On this basis a concept of a full-scale TRD optimized for the hadron identification in the TeV energy region is proposed. Different particle identification techniques were considered and examined. The expected detector performance to reconstruct secondary hadrons produced in forward direction at the LHC is presented.
Geant4 quartz fiber simulations as part of luminometer development for CMS
Authors: Selivanova D A , Popova E V , Ilyin A L , Aydilek O , Ozkorucuklu S , Cerci S , Sunar Cerci D
Published: December 2020

Measurements of luminosity are required to be exceedingly accurate for the new upcoming era of the LHC with higher energies and a more complex structure of the beam (HL-LHC). A new device is being developed for the CMS experiment to fulfill demands of being stand-alone and precise. The paper describes the design, main components and physics behind the new quartz fiber based luminometer (QFL). Via simulations of a single quartz fiber, we were able to calculate an average number of photons reaching the end of the fiber after a single particle hit.
Outlook of the application of the PyCAMFT code for the ISOL installation development
Authors: Barminova H Y , Shalyutin I A
Published: December 2020

Currently the tracking code PyCAMFT, which can be effectively applied for the simulation of the online isotope separators (ISOL), is being developed. The peculiarities and advantages of the code are discussed. The results of the modeling of a multicomponent beam in a simple separator online using the PyCAMFT are given.
Development of the scintillation detector prototypes with SiPM readout for SPD at NICA
Authors: Tishevskiy A V , Gurchin Yu V , Isupov A Yu , Khrenov A N , Kulevoy T V , Ladygin V P , Polozov P A , Reznikov S G , Terekhin A A , Volkov I S
Published: December 2020

The Beam Beam Counter is a system for local polarimetry and local luminosity monitoring at the Spin Physics Detector at NICA. The main option of the Beam Beam Counter is the scintillation counters with SiPM readout. The work presents the first results on scintillation detector prototype using developed Front-end electronics based on the Time-over-Threshold technique. The procedure of the time-walk correction is discussed.
Development of readout chain for CBM Projectile Spectator Detector at FAIR
Authors: Finogeev D , Guber F , Karpushkin N , Makhnev A , Morozov S , Serebryakov D
Published: December 2020

The Compressed Baryonic Matter (CBM) experiment at FAIR needs a detector to measure the nucleus-nucleus collision centrality and orientation of the reaction plane. The Projectile Spectator Detector (PSD) as a sampling lead/scintillator forward hadron calorimeter with transverse and longitudinal segmentation will be used for this purpose. The PSD consist of 44 modules with 10 longitudinal sections in each. Electronics of PSD consist of MPPCs boards mounted directly on detector and readout ADC interface with ADC FPGA board installed into crate distanced on 50m from detector part. ADC has 14-bit resolution and 125MHz digitization rate, Kintex-7 FPGA is placed on the board. Concept of PSD Front End Electronics (FEE) is already designed and most crucial parts including ADC FPGA board already tested and confirmed to be operational. One PSD module (”mini PSD” or mPSD) has been installed into the “mini CBM” (mCBM) assembled at SIS18 accelerator in GSI, Darmstadt, Germany in the framework of the FAIR Phase-0 program. ADC FPGA readout board has been integrated into common DAQ experiment and tested. Details of the mPSD FEE design and test results are shown.
Identification of neutrons and gamma rays using a combination of three algorithms for separating signals of the scintillation detector
Authors: Kirsanov M A , Klimanov S G , Chepurnov A S
Published: December 2020

Scintillation detectors with organic scintillators are widely used for fast neutrons detection in high gamma ray background. The peculiarity of this type of detector is that the pulse shape depends on the type of the detected particle. Traditionally, the Pulse Shape Discrimination (PSD) histogram is used to determine the number of detected neutrons. The PSD parameter is calculated from the shape of the detector pulse and assigned to each pulse. A typical PSD histogram contains two peaks corresponding to neutrons and gamma rays that overlap in the region between the peaks. With this approach, it is impossible to identify each individual signal in the area between the peaks. Therefore, it is not possible to calculate the overall signal identification coefficient. We have proposed a new method for the identification of neutrons and gamma quanta, which includes a combination of three signal separation algorithms: the traditional histogram PSD, the dependence of the area of signals on their amplitude, Tau histogram (tau means the fall constant of the detector pulses). This combination of three algorithms makes it possible to calculate the value of the signal identification coefficient. To test a new method for identifying neutrons and gamma quanta, we used a Pu-Be neutron source, a scintillation detector with a p-terphenyl crystal and a CAEN DT5730 Digitizer (14 bit, 500 MHz). When a scintillation detector registered neutron from a Pu-Be source, the signal identification coefficient was 91.6%. A new method for identifying signals from a scintillation detector is used to register neutrons at the light ion accelerator.
Selection of the optimal parameters of the scintillation hodoscope model for the muonography
Authors: Anoshina E S , Dmitrieva A N , Shutenko V V , Yakovleva E I , Yashin I I
Published: December 2020

This article discusses the problem of selection by modeling the optimal parameters of a new scintillation muon hodoscope created for the development of the muonography method. The muon hodoscope is a scintillation detector consisting of several layers of scintillation strips with fiber optic light collection on silicon photomultipliers (SiPM). Its exact model in the Geant4 software package was developed. With its help, the passage of muons through the detector and the response of the detector to these events are simulated. The reconstruction of the tracks of muons was carried out and the accuracy of their reconstruction was estimated. The obtained distributions of events in the angle between the reconstructed and "real" tracks for various detector parameters and the selection of optimal parameters for the highest accuracy and efficiency of the reconstruction of muon tracks are considered.
High-performance optimization of simulation and reconstruction modules in the BM@N software at the NICA
Authors: Driuk A V , Merts S P , Nemnyugin S A , Roudnev V A , Stepanova M M , Iufryakova A A
Published: December 2020

Results of performance study of the BmnRoot software are presented. The BmnRoot software package plays crucial role in the Baryonic Matter at Nuclotron (BM@N) experiment of the NICA project. It is used for simulation and analysis of experimental data. Various approaches to performance optimization are discussed including algorithmic improvements and parallelization in simulation and reconstruction modules. Results of performance analysis are given and bottlenecks are localized. Results of efficiency and scalability studies for different approaches are also presented.
On mass limits for scalar color octet from the LHC data on the

tt¯tt¯

and

tbtb¯

production.
Authors: Martynov M V , Smirnov A D
Published: December 2020

The full hadron cross section of the scalar octets

F
a

F
a
*

-pairs production at the LHC13 is calculated. From the CMS data on

t
b

t
b

¯

and

t

t
¯

t

t
¯

production cross sections we found the limits on masses of charged

m

F
1

≳

549

−
21

+
27

GeV

and neutral

m

F
2

≳

1336

−
61

+
87

GeV

scalar color octets.
Strange Quark Matter with β-equilibrium condition
Authors: Kumari Manisha , Kumar Arvind
Published: December 2020

Present study explores the properties of strange quark matter (SQM) or strange quark star (SQS) within the Polyakov extended chiral SU(3) quark mean-field (PCQMF) model. Using β-equilibrium condition in the PCQMF model, the analysis of pressure density, and equation of state (EoS) of SQM for different values of vector coupling constant is carried out. Three different conditions of Proto-Quark Star (PQS) along the star evolution (S/nB
= 1, Yl
= 0.4; S/nB
= 2, Yvl
= 0; S/nB
= 0, Yvl
= 0) are considered to perform the theoretical simulation. Providing a significant vector coupling constant, the change in pressure with baryon density is found to be more as compared to zero vector interaction. Further, pressure density shows monotonically and smoothly increasing behavior with an increase in the energy density. The study thus carried out, anticipated to give a better insight in understanding the properties of matter inside the core of supermassive stars in the universe.
Light-Cone Distribution Amplitudes of Doubly-Heavy Baryons
Authors: Parkhomenko Alexander , Shukhtina Alice
Published: December 2020

Doubly-heavy baryons, whose dynamics is determined by a light quark situated in a color field of a static pair of heavy quarks, are investigated. Non-local interpolation currents are introduced and corresponding matrix elements between the baryon and vacuum state are expressed in terms of light-cone distribution amplitudes. Model functions for baryon distribution amplitudes are suggested and their scale dependence is studied in the perturbative QCD framework. The similarity between the heavy meson and doubly-heavy baryon distribution amplitudes is discussed.
Analytical reconstruction of pp elastic scattering amplitudes from the complete sets of experiments at the SPASCHARM facility at U70
Authors: Bogdanov A A , Chetvertkova V A , Kozelov A V , Ladygin V P , Mochalov V V , Nurusheva M B , Okorokov V A , Oreshkov A O , Rykov V L , Semenov P A , Vasiliev A N
Published: December 2020

The direct reconstruction of the pp elastic scattering amplitudes at the energy of 16 GeV is discussed. At the SPASCHARM experiment, the 19 different spin dependent observables will be measured in pp elastic scattering. The suggested selection of observables allows a complete analytical reconstruction of elastic scattering amplitudes as a solution of the system of bilinear equations. A set of physical observables, which are necessary for model independent reconstruction of all five complex elastic pp scattering amplitudes, is defined.
Coordinate-space representation of a charged scalar particle propagator in a constant magnetic field expanded as a sum over the Landau levels
Authors: Iablokov S N , Kuznetsov A V
Published: December 2020

A coordinate-space representation for a charged scalar particle propagator in a constant magnetic field was obtained as a series over the Landau levels. Using the recently developed modified Fock–Schwinger method, an intermediate expression was constructed and symmetrized, thus, allowing for factorization of the series terms into two factors. The first one, a sum of Bessel functions, depends on time and z-coordinate, where the z-axis is chosen to be a direction of the magnetic field, and has a structure similar to the propagator of a free field. The second one, a product of a Laguerre polynomial and a damping exponential, depends on x, y-coordinates, which form a plane perpendicular to the direction of the magnetic field, and ensures the localized propagation in the x, y-plane.
Finding new physics, phenomenological, experimental and astrophysical predictions
Authors: Das C R , Huitu K , Kurmanaliyev Zh , Mauyey B , Kärkkäinen T
Published: December 2020

The crucial phenomenological and experimental predictions for new physics are outlined, where the number of problems of the Standard Model (neutrino masses and oscillations, dark matter, baryon asymmetry of the Universe, strong CP-problem) could find their solutions. The analogies between the cosmological neutrino mass scale from the early universe data and laboratory probes are discussed, as well as the search for new physics and phenomena.
Asymmetric kink solutions of hyperbolically deformed model
Authors: Gani V A , Moradi Marjaneh A
Published: December 2020

We study some properties of kink solutions of the model with non-polynomial potential obtained by deforming the well-known φ
6 field model. We consider the excitation spectrum of the kink. We also discuss the properties of the ‘kink+antikink’ system as a whole that are not inherent to a solitary kink or antikink.
The dual properties of two-color QCD with baryon, chiral and isospin densities
Authors: Khunjua T G , Klimenko K G , Zhokhov R N
Published: December 2020

The phase structure of dense quark matter in the two color case has been investigated with nonzero baryon μB
, isospin μI
and chiral isospin μ

I5 chemical potentials. It has been demonstrated that due to the duality properties the phase diagram is extremely symmetric and the whole phase diagram in the case of two colors can be obtained just by dualities from the phase structure of three color case. This shows that the dualities are rather useful tool.
In-medium J/ψ mass shift by the D meson loop effect
Authors: Chhabra R , Tsushima K
Published: December 2020

The mass shift of the J/^ state in-medium in symmetric nuclear matter with zero and finite temperature and cold strange matter was investigated by an effective Lagrangian plus QCD sum-rule approach. The in-medium mass of the J/ψ state is evaluated through the intermediate pseudoscalar D-meson loop for the J/ψ self-energy. The effect of medium is incorporated through the in-medium mass of D meson calculated using chiral SU(3) model plus QCD sum-rule approach. The self energy loop integral is regularized using the phenomenological form factor of the dipole form. We compare our results with some of the results in the literature. The present results should be helpful to better understand the expected data from heavy ion collision experiments, such as CBM and PANDA.
Production of K(892)*0 mesons in 3He+Au collisions at

sNN=200GeV
Authors: Berdnikov A Ya , Berdnikov Ya A , Borisov V S , Kotov D O , Mitrankov Iu M
Published: December 2020

Collisions of small systems such as p/d/3He+Au are important for the investigation of quark-gluon plasma (QGP) in relativistic heavy ion collisions. These experiments distinguish the effects of the initial state of cold nuclear and the final state of hot matter. The research of light hadron production is one of the leading directions in the effects of the cold and hot nuclear matter studies. Due to a short lifetime and strange quark content, the K
*0-meson is sensitive to the properties of the hot dense matter and strangeness production from an early partonic phase (i.e. QGP). This report presents invariant transverse momentum spectra and nuclear modification factors (RHeAu
) of K
*0-meson as a function of pT
measured in 3He+Au collisions at

s

N
N

=
200

GeV

by the PHENIX experiment. In results, the nuclear modification factors for K
*0-meson in d+Au and 3He+Au collisions are in a good agreement. Values of RHeAu
for K
*0, φ, and π
0 mesons are equal within uncertainties in all centrality bins in the whole pT
range. In conclusion, the obtained results might indicate that CNM effects are not responsible for the differences of K
*0 and φ to π
0 suppression level seen in heavy ion collisions.
Pion femtoscopy in p+Au and Au+Au collisions at

sNN=200GeV

using transport approach
Authors: Kuzina E , Khyzhniak E , Ermakov N , Nigmatkulov G , Alpatov E
Published: December 2020

Correlation femtoscopy provides information about the space-time structure and evolution of the fireball created in ultra-relativistic nucleus-nucleus collisions. The dependence of the femtoscopic radii on transverse pair momentum and charged particle multiplicity of an event reflects the mechanism of collective behavior. In this work, the femtoscopic radii of identical charged pions were calculated in the UrQMD model for Au+Au and p+Au collisions at

s

N
N

=
200

GeV

and compared to each other at the same multiplicities. The physics implications of this comparison will be discussed.
On generalized Melvin solutions for Lie algebras of rank 4
Authors: Bolokhov S V , Ivashchuk V D
Published: December 2020

We consider generalized Melvin-like solutions associated with Lie algebras of rank 4 (namely, A
4, B
4, C
4, D
4, and the exceptional algebra F
4 ) corresponding to certain internal symmetries of the solutions. The system under consideration is a static cylindrically-symmetric gravitational configuration in D dimensions in presence of four Abelian 2-forms and four scalar fields. The solution is governed by four moduli functions Hs
(z) ( s = 1,…,4) of squared radial coordinate z = ρ
2 obeying four differential equations of the Toda chain type. These functions turn out to be polynomials of powers (n
1, n
2, n
3, n
4) = (4, 6, 6, 4), (8, 14, 18, 10), (7, 12, 15, 16), (6, 10, 6, 6), (22, 42, 30, 16) for Lie algebras A
4, B
4, C
4, D
4, F
4, respectively. The asymptotic behaviour for the polynomials at large distances is governed by some integer-valued 4 × 4 matrix v connected in a certain way with the inverse Cartan matrix of the Lie algebra and (in A
4 case) the matrix representing a generator of the ℤ2-group of symmetry of the Dynkin diagram. The symmetry properties and duality identities for polynomials are obtained. We also presented 2-form flux integrals over 2-dimensional discs.
On the Cosmological Origin of Astroparticles: New Concepts, Phenomena and Processes in galactic SMBH
Authors: Avetissian A K
Published: December 2020

The previous theoretical studies concerning the Russian programs OLIMPIA and “Synthesis of heavy elements” are developing based on original cosmological phenomenon of “gravitons’ entanglement”, revealed in scope of Non-Inflationary Cosmology theory, created by author. The broad review of this theoretical concept together with prediction of “initial cosmic quasiparticles” – mixture of correlated carriers of the fundamental physical fields in their vacuum states – were able to initiate another phenomenon, so called “large-scale entanglement of the prototypes of astroparticles”. These phenomena could generate within earliest Universe and be continued even during the formation of galaxies, when the trapped inside the SMBH initial Bose-condensate could become a large-scale coherent state through the induced gravitational collapse, turning further into an effective model of a galactic source of high energies. Such a model is able to verify the theoretical mechanism of the galactic jet.
Evolution of the cluster of primordial black holes within the Fokker-Planck approach
Authors: Stasenko V D , Kirillov A A
Published: December 2020

The calculation results of the evolution of the cluster of primordial black holes based on the Fokker-Planck equation with neglecting of the gas accretion onto black holes are presented. In addition, we consider how a massive black hole located within the cluster center affects on its evolution. Despite it creates an additional potential in the central region of the cluster and might capture surrounding black holes, a negligible growth rate of a central black hole was shown for 1 Gyr. Furthermore, we find a significant (approximately tenfold) expansion of the cluster.
Multi-messenger cosmology of new physics
Authors: Khlopov M Yu
Published: December 2020

The observational evidence for the inflationary cosmology with baryosynthesis and dark matter/energy can be viewed as the messenger for new physics, which governed the Universe origin, evolution and structure. To specify the physics beyond the Standard model (BSM), underlying the modern cosmological paradigm additional model dependent messengers are proposed, involving multi-component and composite dark matter, meta-stable particles, primordial black holes and antimatter domains in baryon asymmetrical Universe.
Primordial Black Holes Around Us Now, Long Before, and Far away
Authors: Dolgov A D
Published: December 2020

Recent astronomical data on black holes observations are reviewed. The arguments in favor that the observed black holes are predominantly primordial (PBH) are presented. The mass spectrum of PBH is best fit to the log-normal one. A model of PBH formation with log-normal spectrum is briefly described.