SCIENCE BRINGS NATIONS TOGETHER The XXV International Scientific Conference of Young Scientists and Specialists (AYSS-2021)

11 Oct 2021, 09:00 → 15 Oct 2021, 18:00 Asia/Almaty

 

 

The XXV International Scientific Conference of Young Scientists and Specialists (AYSS-2021) which will be held in mix format from 11 to 15 October 2021 at the Institute of Nuclear Physics (INP) of the Ministry of Energy of the Republic of Kazakhstan, Almaty. The Conference is held annually and attended by students, young scientists and specialists from scientific centers over the world. The selected talks will be recommended to be published in the refereed journal. Participation in the Conference will be confirmed by a certificate.

The conference is dedicated to the 65th anniversary of JINR and the 30th anniversary of the Independence of the Republic of Kazakhstan.

All events within the conference will be held in compliance with the sanitary and epidemiological requirements to prevent the spread of the coronavirus infection COVID-19.

TIMETABLE

Please, be aware that the time is indicated in Asia/Almaty timezone, Moscow time is 3 hours less.

TOPICS 

Within the framework of the Conference leading scientists will give lectures on the recent theoretical, experimental and applied investigations conducted all around the world with emphasis on the major results obtained at JINR. All participants are encouraged to submit abstracts on the following topics: 

• Theoretical Physics
• Mathematical Modeling and Computational Physics
• High Energy Physics
• Particle Accelerators and Nuclear Reactors
• Experimental Nuclear Physics
• Information Technology
• Condensed Matter Physics
• Applied Research
• Life Science

PARTICIPANTS

Students, young scientists and specialists under 35 years from all over the world are invited to participate in the Conference with oral presentations. The registration will soon be open. 

 

SCIENTIFIC ADVISORY BOARD:	ORGANIZING COMMITTEE:
Co-chairman: Batyrzhan Karakozov (INP)	Co-chairman: Aidos Issadykov(INP & JINR)
Co-chairman: Grigory Trubnikov (JINR)	Co-chairman: Nikolay Voytishin(JINR)
Vice-chairman:Grigory Shirkov (JINR)	Alexey Aparin(JINR)
Nikolay Arsenyev (BLTP JINR)	Askhat Bekbaev (INP)
Vladimir Chausov (LRB JINR)	Anton Dolzhikov(JINR)
Alexander Cheplakov (VLHEP JINR)	Daniyar Janseitov (INP)
Otilia Culicov (FLNP JINR)	Inna Kolesnikova(JINR)
Olga Derenovskaya (LIT JINR)	Olga Korotchik(JINR)
Alexander Karpov (FLNR JINR)	Dmitry Pugachev(JINR)
Alexander Verkheev (DLNP JINR)	Anna Rybakova(JINR)

THE WORKING LANGUAGE of the Conference is English.

THE REGISTRATION FEE for in-person participation will be 140$ and will cover coffee-breaks, the conference dinner and the social program event. 

On-line participation is free of charge.

For a limited number of participants AYSS will cover partially their travel expences.

SECTIONS

During the conference, the participants will present their reports in one of the nine topical sections.

AYSS-2021_poster.pdf

Monday 11 October

09:00 → 09:30 Registration

What should be description?

Karakozov B.K._11.10.2021.pdf

09:30 → 09:45 Opening

https://jinr.webex.com/jinr/j.php?MTID=meb12aaca113321b28f8c123868a1ac0f

ayss2021.pdf

09:45 → 10:45 Plenary session

https://jinr.webex.com/jinr/j.php?MTID=meb12aaca113321b28f8c123868a1ac0f

09:45 Machine Learning in HEP

Speaker: Prof. Sergei Gleyzer

10:45 → 11:00 coffee break

11:00 → 12:00 High energy physics

https://jinr.webex.com/jinr/j.php?MTID=meb12aaca113321b28f8c123868a1ac0f

11:00 MiniSPD - cosmic muon testing facility

MiniSPD is setup for cosmic muon tests. MiniSPD includes most of types of detectors that will be used in SPD detector . Detectors and readout electronics for the NA64 experiment were used as the main test object. The MiniSPD setup includes a scintillator trigger system, straw, silicon and GEM trackers, an electromagnetic calorimeter, and a lead filter to remove low energy components of cosmic rays. Also, the main goal of MiniSPD was to measure such important parameters of prototypes of detectors as spatial and time resolution, efficiency, drift characteristics, gas gain, data acquisition parameters, implementation of slow control and features of online monitoring systems. The data from the stand can be used for further preparation of the infrastructure of the beam zone, also to study of such systems as power supply, climate control systems, etc.

Speaker: Ysmaiyl Kambar (JINR)

11:15 Centrality determination in MPD at NICA

We present a study of centrality class determination based on number of charged particles registered with Time Projection Chamber in Multi-Purpose Detector at NICA complex. Precise determination of centrality classes will allow to select the ion collisions within a certain class of initial conditions in order to study behavior of some variables on the mean energy densities reached.
It will be important to study the QCD matter with respect to the geometric properties of the collision between nuclei, but these properties cannot be experimentally measured. Therefore, we compare in this work the centrality classes which are obtained using different sets of observables as proxies for centrality, They include the number of hits in the TPC and transverse momentum of registered particles in the TPC sub-detector for Bi+Bi collisions at $\sqrt{S_{NN}} =$ 7.7, 9 and 9.46 GeV, Data generated by several Monte Carlo models are used. Results are discussed.

Speaker: Pedro A. Nieto (Universidad Autónoma de Sinaloa, Facultad de Ciencias Físico-Matemáticas)

Centrality_determination_in_MPD_at_NICA_AYSS2021_F1.pdf

11:30 Study of radiation losses in Electromagnetic Calorimeter of MPD experiment

The Multi-Purpose Detector (MPD) is one of the experiments of the NICA collider in Dubna. The construction of MPD consists of many detectors and components for study of quark-gluon plasma. The main purpose of Electromagnetic Calorimeter (EMC) is to measure the coordinates and energy of electrons, positrons and photons generated in heavy ion collisions. Due to its high temporal resolution, the calorimeter can play an important role in particle identification and serve to measure the total energy flux, therefore it is important to study radiation losses and material budget of Electromagnetic Calorimeter.

Speaker: Demezhan Myktybekov (Joint Institute for Nuclear Research (JINR))

Demezhan Myktybekov_pdf_ver.pdf

11:45 Study of spectator charge distributions in the HADES experiment for Ag+Ag@1.58AGeV and Au+Au@1.23AGeV

Fragments charge has been measured with the forward hodoscope (FWall) in the HADES experiment for Ag+Ag@1.58AGeV and Au+Au@1.23AGeV. First results on the nuclei fragments description with the framework of the DCM-QGSM-SMM model and comparison with the experimental data will be presented. The description of the fragments' charges with the model is a crucial task for centrality determination and geometrical properties of the nucleus-nucleus collisions.

Speaker: Elizaveta Zherebtsova (Ms.)

12:00 → 13:30 Lunch time

13:30 → 14:30 Plenary session

https://jinr.webex.com/jinr/j.php?MTID=meb12aaca113321b28f8c123868a1ac0f

13:30 Nuclear reaction models

Speaker: Prof. Timur Zholdybayev

14:30 → 15:30 High energy physics: Section 1

https://jinr.webex.com/jinr/j.php?MTID=meb12aaca113321b28f8c123868a1ac0f

14:30 GEM residuals corrections in Monte-Carlo simulation for the Run6 at the BM@N experiment

BM@N (Baryonic Matter at Nuclotron) is the first experiment with a fixed target at the NICA Facility at JINR (Dubna). It is designed to study nuclear-nuclear collisions at high densities. Nuclotron provides heavy ion beams with energies ranging from 2.3 GeV to 4.5 GeV, which is suitable for studying strange mesons and multi-strange hyperons close to the kinematic threshold.

In the talk the procedure of the residual corrections of simulated Monte-Carlo (MC) events will be presented.

It is one of the intermediate stages of the BM@N experiment data analysis. These corrections allow to improve the accuracy of the track reconstruction procedure in Monte-Carlo simulation and physics data.

Speaker: Ms Ksenia Alishina (JINR LHEP)

14:45 Deep underground neutrino experiment DUNE – calculation of sensitivity to the measurement of oscillation parameters

Neutrinos have a special place in the physics of elementary particles. Neutrinos are the lightest particles, leptons that can change their flavors, i. e. oscillate, propagating through the vacuum or matter. Neutrino oscillations are a phenomenon that has been activity studied during the past decades and have a lot of undecided problems at the moment. Working now accelerator experiments, such as NOvA and T2K, make a significant contribution to the development of the neutrino oscillation physics. However, they have some restrictions. For example, neutrino possesses a tiny interaction cross section with the matter, so enormous detectors volumes are needed for their observation. Therefore at the present, a huge accelerator experiment DUNE is been creating for investigations at opened questions in the field of neutrino physics, including the neutrino oscillation physics.
In this work calculation of sensitivity DUNE to precise measurement of oscillation parameters describing neutrino oscillation in the three-flavor paradigm of the extended Standard Model of elementary particles was determined. DUNE modeling was built in a specialized simulator of neutrino experiments GloBES, as well as with software of neutrino analysis GNA. From simulation numbers of rates that were supposed to a true were calculated, then analysis with methods of statistical hypotheses was realized. Thus sensitivities to CP violation in the lepton sector (δCP), to mass hierarchy defining (∆m32) and to an octant in which one of mixing angles locates (θ23) were plotted. Finally, comparative characteristics for two independent software (GloBES and GNA) was considered due to each of them has particular qualities.

Speaker: Ann Stepanova

DUNE_sensitivity.pdf

15:00 East-West asymmetry in atmospheric muon fluxes in the Far Detector of NOvA

Far Detector of the NOvA experiment is located on the surface unlike most of the neutrino detectors. This fact allow us to study cosmic rays in there. One can measure atmospheric muon fluxes and explore their angular dependences. But this research is complicated by the fact that Fsr Detecor overburden and the rock surrounding it are also asymmetrical

Speaker: Olga Petrova (JINR)

EWA_Petrova.pdf

15:15 Study of acceptance of ECal detector of the HADES experiment

HADES is a large acceptance spectrometer operating at SIS18, GSI, Germany. It is aimed at exploration of QCD phase diagram at the ion beam energies of 1-2 AGeV in the region of high hadron densities. HADES setup includes a superconducting toroidal magnet, sets of drift chambers, ring-imaging Cherenkov detector, TOF systems and a new electromagnetic calorimeter (ECAL).
The Ecal detector covers almost full azimutal angle and range of polar angles 12 ̊ < θ < 45 ̊. In order to extract yield of π0 mesons through its π0→γγ decay the acceptance corrections are needed. This talk is devoted to the procedure of determination of acceptance of the ECal detector.

Speaker: Arseniy Shabanov (INR RAS)

Shabanov_AYSS_HADES_ECal_acceptance.pdf

14:30 → 15:30 Life Science

https://jinr.webex.com/jinr/j.php?MTID=m23f10d08e276f37848aa98c276790793

14:30 44mSc/44gSc generator based on the after-effects of radioactive decay

A stable complex of radionuclide with suitable chelator is one of the key components in design of the radiopharmaceuticals for nuclear medicine. In certain cases the radioactive daughter might be fully or partially released from the complex due to so-called ‘after-effects’, which create the challenges in application of such radiopharmaceuticals [1]. The after-effects strongly depend on the decay mode, chemical difference of parent and daughter radionuclide and the choice of the chelate.
44gSc presents a particular interest for application in nuclear medicine as a positron emission tomography (PET) agent due to its favourable nuclear properties, such as t1/2 = 3.97 h, Eβ+max = 1.47 MeV, branching ratio 94.3 % β+ [2]. However, due to short half-life 44gSc has limitation in transportation and carrying out longer pharmacokinetic studies. 44mSc (t1/2 = 58.61 h) decays by isomeric transition (IT) into 44gSc accompanied by 12% of conversion electron emission, which can cause a partial release of the daughter 44Sc from the chelate complex. The after-effects in 44mSc/44gSc pair can be considered as an advantage in the context of the generator to produce a radiochemically pure 44Sc, and disadvantage in case of in vivo generator [3,4].
In present work, 44mSc/44gSc generator based on the radiolabeling of DOTATOC and C-18 cartridge with both metastable and ground state of scandium-44 was designed and tested. Both isotopes were produced via 44Ca(p,n)44m,gSc reaction from natural calcium target irradiated at TR13 MeV cyclotron at TRIUMF. The final product was purified using solid ion-exchange chromatography and radiolabeled with 10-4 M DOTATOC. Further analysis was performed using instant thin layer chromatography (iTLC) and gamma-spectroscopy with HPGe detector.
The yield of the daughter isotope release was equal to 9.68±1.15%. This result demonstrates not only fundamental importance of the after-effects in nuclear medicine, but also its impact on the radiopharmaceutical synthesis. Moreover, the production of the parent 44mSc via other routes (e.g. 41K(α,n)44mSc, natTi(p,2pxn)44mSc using medium and high energy protons, 42Ca(α,pn)44mSc) would give the opportunity for generator source of 44gSc to enable transport and kit labeling synthesis directly in the medical facility.
References
[1] Kurakina ES, Radchenko V, Belozub AN, Bonchev G, Bozhikov GA, Velichkov AI, et al. Perturbed Angular Correlation as a Tool to Study Precursors for Radiopharmaceuticals. Inorg Chem 2020;59:12209–17. https://doi.org/10.1021/acs.inorgchem.0c01208.
[2] Filosofov D V., Loktionova NS, Rösch F. A 44Ti/44Sc radionuclide generator for potential application of 44Sc-based PET-radiopharmaceuticals. Radiochim Acta 2010;98:149–56. https://doi.org/10.1524/ract.2010.1701.
[3] Rosch F, Knapp FF. 40 Radionuclide Generators. Handb. Nucl. Chem., Springer Science+Business Media B.V.; 2011, p. 1936–67. https://doi.org/10.1007/978-1-4419-0720-2.
[4] Edem PE, Fonslet J, Kjær A, Herth M, Severin G. In vivo radionuclide generators for diagnostics and therapy. Bioinorg Chem Appl 2016;2016. https://doi.org/10.1155/2016/6148357.

Speaker: Ms Elena Kurakina (1)JINR 2)MUCTR 3)TRIUMF)

14:45 The effect of DNA synthesis inhibitor on DNA damage induction in melanoma cells after exposure to protons

Increasing the radiosensitivity of normal and tumor cells is one of the priority aims of modern radiobiology. The agents that modify the yield of DNA double-strand breaks (DSBs) which are lethal to cells are of particular interest. We have previously shown that under the influence of DNA repair inhibitors - 1-β-D-arabinofuranosyl cytosine (AraC) and hydroxyurea (HU) the DNA DSBs yield on cells of various types increases under the action of ionizing radiation. The mechanism of this process is based on the long-term non-reparable DNA single-strand breaks (SSBs) conversion into enzymatic DSBs.

The main aim of this research was to elucidate the molecular and cellular effects of the proton action on the murine melanoma B16 cells under the influence of AraC and HU. The samples for analysis were taken after 2 and 10 days of melanoma cells transplantation into the animals and irradiation with protons at a dose of 10 Gy. Two modifications of quick and highly sensitive comet assay were carried out: in neutral conditions to detect DNA double-strand breaks, and in alkaline conditions to detect DNA single-strand breaks. It was found that the amount of DNA SSBs and DSBs significantly increases under the influence of AraC. This difference persists in the post-radiation period up to 10 days.

Speaker: Regina Kozhina (LRB)

15:00 ASSESSMENT OF SELECTED RARE EARTH ELEMENTS, HF, TH, U IN THE DONETSK REGION USING MOSS BAGS TECHNIQUE

To assess the accumulation of rare earth elements, Hf, Zr, Th, and U in moss species the active moss biomonitoring technique was applied in the Donetsk region. Moss bags with the Ceratodon purpureus and Brachythecium campestre species were exposed for six months in the surroundings of two parks, two steelworks, and a power station. The concentrations of 12 elements (Sc, La, Ce, Nd, Sm, Tb, Yb, Eu, Hf, Zr, Th and U) were determined in the moss transplants by neutron activation analysis. The degree of ambient contamination has been studied using the relative accumulation factor, contamination factor, pollution load index and enrichment factor. Geochemical indices – ternary plot of Sc–La–Th, ratios of normalized concentrations of light rare earth elements and heavy rare earth elements, possible anomalies of Eu, and chondrite normalized rare earth element curves were used to prove the geochemical origin of rare earth elements. The chondrite-normalized rare earth element patterns of both moss species showed light rare earth elements enrichment and a negative Eu anomaly.

Speaker: Anastasiya Sergeeva (Sergeevna)

15:15 Induction of DNA damage in neuronal cells of mice under the influence of repair inhibitors under the action of gamma-rays in vivo

The search for approaches aimed at changing the sensitivity of cells to the action of ionizing radiation is one of the priority tasks of radiobiology. Studies of the modifying action of agents that affect the processes of DNA damage repair in the cells of the central nervous system (CNS) appear to be promising. In this regard, agents that influence the yield of DNA double-strand breaks (DSB) are of interest. We have previously shown that under the influence of inhibitors of DNA repair - 1-β-D-arabinofuranosyl cytosine (AraC) and hydroxyurea (HU), the yield of DNA DSB increases upon γ-irradiation of cells of various types in vitro. The mechanism of this process is based on the transformation of long-term non-repairable single-strand breaks (SSB) of DNA into enzymatic DSB. In this case, the magnitude of the modifying effect of these agents depends on the quality of the radiation.
In this work, we performed a comparative analysis of the induction and repair of DNA SSB and DSB in neuronal cells of mice (hippocampus and cerebellum) under γ-irradiation after intraperitoneal administration of AraC and AraC/HU combination in vivo.
DNA comet assay method was used to study the regularities in the formation of DNA SSB and DSB in cells from hippocampus and cerebellum of mice under the action of γ-radiation in vivo, under the influence of AraC and HU. It was found that for all types of cells used, there is a linear character in the yield of DNA lesions. It has been shown that the amount of DNA SSBs and DSBs formed during irradiation under the influence of AraC significantly increases. An additional increase in the yield of DNA SSBs and DSBs is observed under the combined action of AraC and HU.
The kinetics of DNA SSB and DSB repair was studied under the influence of radio modifiers. It has been shown that the kinetics of DNA SSB and DSB repair both in hippocampal and cerebellar cells is complex. Up to 4 hours post-irradiation, an increase in the yield of DSB is observed to the maximum values, after which their decrease is observed for all types of cells. Although the kinetics of SSB repair, as well as for DSB, exhibits a biphasic character, differences are also observed depending on the cells. Thus, for cerebellar cells, the maximum of SSB shifts by 2h post-irradiation; for hippocampal cells, the maximum of SSB are similar with the maximum observed for DSB and falls on 4h post-irradiation. Under the conditions of the influence of AraC alone and the combined influence of AraC/HU, an increase in the total amount of damage is observed during the entire post-irradiation period observed in the experiment.

Speaker: Mrs Sabina-Emanuela Erhan (Joint Institute for Nuclear Research/UBB/INCDTIM)

14:30 → 15:30 Particle accelerators and nuclear reactors

https://jinr.webex.com/jinr/j.php?MTID=m90f9278cba9f80b025fd3f9fc584ce38

14:30 PROGRESS ON NEW BEAM LINES DESIGN AND CONSTRUCTION FOR APPLIED RESEARCH AT NICA

The new beam channels and stations for applied research of NICA complex are currently under construction at JINR, pursues the goal of study of radiobiology and electronic component irradiation by high-energy and low-energy ion beams. A detailed technical design for magnet and vacuum systems is ready. A construction of these systems has been started. The installation and commissioning are planned for summer 2022 followed by the first beam run in autumn 2022. In the paper, the project status overview is given and practical technical highlights are presented.

Speaker: Georgii Filatov (JINR)

AYSS Filatov21 11.10.21.pdf

14:45 Construction of stations for applied research at the NICA accelerator complex at JINR

On the basis of the NICA accelerator complex applied stations: ISCRA (energy range of 150 - 500 MeV/n), SOCHI (ion energy up to 3.2 MeV/n), and SIMBO (energy range 500-1000 MeV/n) are under construction for single event effects testing of as capsulated, so decapsulated microchips, and for radiobiological researches and modelling of influence of heavy charged particles on cognitive functions of animal's brain respectively. This paper presents the applied stations description. Mounting and commissioning of the SOCHI station are planned for autumn 2021, the ISCRA and SIMBO stations are planned in early 2022. Experiments at the SOCHI are to start in spring 2022, at the ISCRA and SIMBO are planned in autumn 2022.

Speaker: Mr Alexey Slivin (Joint Institute for Nuclear Research, Dubna, Russia)

15:00 Impedance Budget of the NICA Collider Ring

The report presents the results of optimization of the longitudinal coupling impedance of the NICA collider ring using numerical simulation of its individual elements by the CST Studio. Based on the obtained results, analytical estimates of the stability of the ion beam in the ring are obtained for two energy values – 1 and 3 GeV/u. To confirm the reliability of the obtained calculations, the longitudinal impedance was measured for a prototype of one of the calculated elements.

Speaker: Sergey Melnikov (JINR)

15:15 Power supplies systems for testing and certification of superconducting magnets for accelerator complexes NICA and FAIR

Assembling, testing, investigating and certification of superconducting magnets for accelerator complexes NICA (Nuclotron - based Ion Collider fAcility) and FAIR (Facility for Antiproton and Ion Research) are managed by Superconducting Magnets Department at Joint Institute for Nuclear Research. Different types of power supplies are applied for feeding the superconducting magnets during the tests. A power supply area for this purpose was commissioned. Equipment and technical decisions for the power supply area are described in this work.

Speaker: Mr Aleksey Kudashkin (JINR)

AYSS-2021_Kudashkin.ppt

15:30 → 15:45 coffee break

15:45 → 17:15 High energy physics

https://jinr.webex.com/jinr/j.php?MTID=meb12aaca113321b28f8c123868a1ac0f

15:45 Wire tension test bench for gaseous detectors

A test bench for determining the wire tension of gaseous detector was designed. The tension of the wires is checked by measuring the resonant frequencies of their vibrations. In this work the development of the key modules of the test bench and the corresponding software are presented. The results of stand testing during the production of detectors for the SPD Muon System Prototype (NICA/JINR) are shown.

Speaker: Viktoriya Zel

AYSS2021_Zel.pdf

16:00 Monte Carlo simulation of the experimental setup for measurements of entangled annihilation photons

This work presents the results of Monte Carlo simulation of the
experimental setup for study the Compton scattering of annihilation
photons in GEANT4. The pair of entangled annihilation photons is born as
a result of electron-positron annihilation at rest. The experimental
setup consists of Compton polarimeters that include the plastic
scatterers and two groups of NaI(Tl) detectors of scattered gammas
azimuthally situated around the setup axis. The energy deposition
spectra in Compton scatterers and NaI(Tl) detectors are studied. The
behavior of the azimuthal correlations of the scattered photons were
obtained for a few different cases: a) a pair of photons with random
polarizations b) photons with mutually orthogonal polarizations c)
photons in a state of quantum entanglement. Clear distinctions in
azimuthal correlations for these cases are observed in simulation that
allows the comparison the experimental results with the theoretical
predictions.

Speaker: Sultan Musin (MIPT)

Musin_AYSS21.pdf

16:15 Analysis of average pseudorapidity distributions of secondary particles formed in interactions of Au 10.7 AGeV and Pb 158 AGeV with emulsion nuclei.

A comparison is made of the average pseudorapidity distributions <η> of secondary particles produced in interactions of 197Au gold nuclei with an energy of 10.7 A GeV and 208Pb 158 A GeV lead nuclei with emulsion nuclei Em for events of different types.
To understand the mechanism of formation of the final states of secondary particles, the parameters of interaction fragmentation were analyzed. All events were divided into 3 types. The first type includes events with one multi-charged fragment of projectile nucleus. Most often, such events are called cascade-evaporation ones. They are characterized by weak multi-particle correlations in the pseudorapidity distribution of secondary particles.
The second type corresponds to explosive processes occurring with the destruction of the projectile nucleus into several multi-charged fragments. Most of these events are characterized by strong multi-particle correlations in the pseudorapidity distribution of secondary particles.
The third type corresponds to the complete destruction of the projectile nucleus, i.e. a state with a complete absence of multi-charged fragments. In such events a huge nucleus of gold or lead is completely destroyed after interaction with a much smaller nucleus of the emulsion. The dynamics of these processes, as well as studies of events of the second type, attract the greatest attention of experimenters and theorists, primarily from the point of view of the search and study of quark-gluon plasma and mixed phase nuclear matter.
Analysis of the results allows us to conclude that there is a significant difference in the development of the dynamics of a multi-particle process with a change in the interaction energy of nuclei.
The nuclei of gold and lead have approximately the same mass, but differ in energy by almost 15 times. However, the relative number of explosive events is almost the same. In Au + Em interactions, 64.7% of explosive events are observed. Moreover, 8.1% of interactions are events of complete destruction, in which there are no fragments of the target nucleus. The Pb + Em interactions account for 59.7% of explosive events and 8.9% of total destruction events. However, the number of events with large values of the average distribution of pseudorapidity <η> differs significantly. In Au + Em interactions, 35.6% of events are explosive events with large values of <η>. There are only 8.4% of such events in Pb + Em.
Thus, the relative number of events of complete destruction of the target nucleus practically does not depend on the energy of the primary nucleus. The number of events with the destruction of the projectile nucleus into several multi-charged fragments is significantly more at 10.7 A GeV than for 158 AGeV.
This paper was supported by a grant from the Ministry of Education and Science of the Republic of Kazakhstan No. BR10965191

Speaker: Anastasia Fedosimova

16:30 Influence of the initial conditions of interaction on the development of a cascade process.

The energies of cosmic particles have been measured quite accurately for particles with energies E <0.1 TeV. Modern magnetic spectrometers can determine the primary energy with an error of less than 10 percent. However, such devices are limited at energies E> 1 TeV. In the region of 1-100 TeV, there is a lack of measurement methods. In this regard, various space experiments present extremely contradictory energy spectra in the energy range 1-100 TeV.
Today, the best option for measuring the energy of various nuclei in a wide energy range (at E> 1 TeV) is the ionization calorimeter method. In a thin calorimeter, the entire cascade of secondary particles is not recorded, but only the beginning of the cascade is measured. Unfortunately, such measurements usually have errors of more than 50% due to significant fluctuations in the development of the cascade.
To solve this problem, we propose to use so-called correlation curves, which are practically independent of fluctuations in the development of the cascade.
The dependence of the energy release at a certain observation level on the rate of development of the cascade was used as the measured values for plotting the correlation curves.
On the basis of computer simulation, it is shown that the proposed technique allows one to determine the energy of primary particles, the cascades of which have not reached their maximum. Thus, particles of higher energies can be analyzed. In addition, the accuracy of determining the energy of particles with energies of TeV and higher is increased. Measurements” of the modeled cascades based on the proposed approach of correlation curves have errors of less than 10%.
This work was supported by a grant from the Ministry of Education and Science of the Republic of Kazakhstan No. AP09562078.

Speaker: Anastasia Fedosimova

16:45 Assessing the centrality degree of relativistic nucleus-nucleus interactions

Experiments on the study of colliding beams have great potential for studying the formation of secondary particles in relativistic nucleus-nucleus interactions. But, unfortunately, they do not have enough information about the initial stage of interaction. In this regard, it is difficult to separate dynamic fluctuations associated with the formation of quark-gluon plasma from fluctuations caused by the features of the initial stage of interaction. Experiments with a fixed target have a significant advantage in studying the initial state of the interaction, since they make it possible to register fragments of the projectile-nucleus and target-nucleus.
The present analysis has been carried out with the data obtained from nuclear emulsion track detector.
Stacks of NIKFI BR-2 emulsions (containing Ag, Br, C, N, O, and H nuclei) have been exposed to a 10.6 AGeV ^{197}Au beam at Brookhaven National Laboratory synchrotron.
Based on the analysis of fragments of interacting nuclei, criteria for assessing the degree of peripherality (centrality) of nucleus-nucleus interaction have been developed.
One of the most optimal parameters for assessing the degree of centrality of the interaction is the dependence of the number of fragments of the target-nucleus Nh on the multiplicity of particles ns.
For Au + AgBr interactions, the average Nh-ns distribution demonstrates a steady increase, and then reaches a plateau. The Au + CNO distribution shows similar behavior, but with a lower multiplicity. This behavior reflects the degree of peripherality of the interaction. On the growing branch of the middle Nh-ns curve, the lower the multiplicity, the higher the peripherality of the interaction. After reaching the maximum value of Nh, an increase in the multiplicity of events corresponds to an increase in the degree of centrality of the interaction.
The study was carried out with financial support from the Ministry of Education and Science of the Republic of Kazakhstan (Grant No. AP09562078).

Speaker: Mrs Saera Ibraimova (Institute of Physics and Technology, Almaty, Kazakhstan)

17:00 DETERMINATION OF DIFFERENTIAL CROSS SECTION OF THE REACTION $pp →\{pp\}_Sπ^0$

The reaction $pp → dπ^+$, which is a classical method of studying $NN$ interactions, has two peaks in the energy dependence of the differential cross section at zero angle $dσ(0)/dΩ$. The first one is located in the region of the sum of the $NΔ(1232)$ masses, $√s ≈ 2.15$ GeV. When analyzing the ANKE-COSY data, a similar peak was found in the reaction $pp →\{pp\}_Sπ^0$, the spin-isospin partner of $pp → dπ^+$. Here $\{pp\}_S$ denotes a diproton, i.e. an unrelated interacting proton pair in the $^1S_0$ state. The previously published ANKE-COSY data also indicate the possibility of the existence of a similar second peak.

Partial wave analysis shows that the first peak for the $pp → dπ^+$ reaction is caused by three dominant transitions exhibiting resonant behavior in the intermediate two-baryon system: $^1D_2p$, $^3F_3d$ and $^3P_2d$; and for the reaction $pp →\{pp\}_Sπ^0$ by two transitions $^3P_2d$ and $^3P_0s$. The transitions responsible for the second peak remain much less clear.

In order to study the second peak on the ANKE-COSY facility, the reaction $pp →\{pp\}_Sπ^0$ was additionally investigated at small angles in the beam energy range $T_{beam} = 1.0 - 2.8$ GeV. For the reaction $pp →\{pp\}_Sπ^0$ we obtained the angular dependences of the differential cross section $dσ/dΩ$ at forward angles for several energies, the energy dependences of the cross section at zero angle $dσ(0)/dΩ$ and of the forward cross section angular slope $k$.

The obtained results confirm the existence of a second peak in the $dσ(0)/dΩ$ energy dependence for the reaction $pp →\{pp\}_Sπ^0$ and allow us to estimate its maximum, mass and width. The change in the sign of the slope $k$ in comparison with the region of the first peak indicates a change in the reaction dynamics at the energies $√s ≈ 2.3−2.6$ GeV.

The obtained results can contribute to the development of a theoretical understanding of the hadron interaction mechanisms in this energy range.

Speaker: Bota Baimurzinova (Joint Institute for Nuclear Research, Dubna, Russia; L. N. Gumilyov Eurasian National University, Nursultan, Kazakhstan)

Baimurzinova.pdf

15:45 → 16:45 Particle accelerators and nuclear reactors

https://jinr.webex.com/jinr/j.php?MTID=m90f9278cba9f80b025fd3f9fc584ce38

15:45 Development of the Test Facility for Measurements of Current-Voltage Сharacteristics of HTS Tapes, Cables and Magnets for SMES at JINR

Superconducting Magnetic Energy Storage (SMES) is a magnet that is under development to improve the quality of the power system of Booster and Nuclotron of NICA magnets. The test facility for measuring current-voltage characteristics (CVC) of HTS tapes, cables and windings for SMES was developed. This test bench is based on National Instruments equipment and power supplies TDK Lambda. The commissioning test facility and the research equipment are described in this work. The results of the CVC measurement of HTS samples for SMES are presented.

Speaker: Bohdan Kondratiev (JINR)

16:00 Optimization parameters of reactivity modulator for reactor NEPTUN, to reduce the level of power fluctuation

Due to the specificity of the kinetics, fluctuations in the power of pulses in pulsed reactors are tens of times higher than in stationary reactors and make problems for the control of the apparatus. This paper proposes and substantiates a method for a significant reduction in the level of fluctuations in power pulses of the reactor NEPTUNE (pulsed reactor project) by adjusting configurations and parameters of reactivity modulator

Speaker: Mr AHMED HASSAN (A A Hassan)

Ahmed's peresentation 11-10-2021.pptx

16:15 The Study of Stability of Compensated Colliding Beams

The luminosity of a collider is proportional to the particle density in a beam. The focusing electric field of a colliding beam restricts the particle density, so the particle density of a beam degrades, so the luminosity does.
Non-linear focusing compensation in a storage ring done by the opposite-charge beam circulating in another storage ring was proposed and tested many years ago. [1]. Ya. S. Derbenev has shown that such a scheme does not allow the significant improvement of luminosity [2]. However, the state of the art accelerator technology has made great progress, and a new type of accelerator has appeared – the energy recovery linac.
In this work, the stability of coherent betatron oscillations is considered in a simple model of rigid bunches. In particular, the “figure-8” collider with electron-positron beams of equal currents, but different energies, colliding at zero angles, is considered. Another scheme to be considered is the collider based on electron energy recovery linac (ERL) and “figure-8” positron storage ring with beams of equal currents. Positrons are circulating in a two-loop storage ring (positron-positron collider), and the electron-electron collider uses ERL, as in original Tigner’s proposal [3]. Thus, a collision of four bunches and space-charge compensation in a multi-bunch mode can be ensured. The mathematical and numerical analysis of these configurations is presented.

---

1. J.P. Koutchouk Beam-beam compensation schemes / J. P. Koutchouk,
   V. Shiltsev // Handbook of Accelerator Physics and Engineering, Second Edition / A. W. Chao, K. H. Mess, M. Tigner, F. Zimmermann. Singapore: World Scientific, 2013, pp. 391-394.
2. Derbenev Ya. S. Collective instability of compensated colliding beams /
   Ya. S. Derbenev // Proc. of the 3rd All-union Conf. on Charge Particle Accel., Moscow, 1972, pp. 382-385. SLAC TRANS-151, 1973.
3. S. B. Lachynov, N. A. Vinokurov Beam-beam compensation in a collider
   based on energy recovery LINAC and storage ring // AIP Conference Proceedings 2299, 020011 (2020)

Speaker: Shamil Lachynov (Budker Institute of Nuclear Physics)

The Study of Stability of Compensated Colliding Beams.pdf

Tuesday 12 October

10:00 → 10:15 coffee break

10:15 → 12:00 Condensed Matter Physics

https://jinr.webex.com/jinr/j.php?MTID=m90f9278cba9f80b025fd3f9fc584ce38

10:15 HIGH ENERGY HEAVY ION RADIATION TOLERANCE OF CRYSTALLINE AND AMORPHOUS Si3N4

The critical issue of modern nuclear energetics is the disposal of radioactive waste resulting from the nuclear fuel cycle. One of the promising ways to reduce their radiotoxicity is the neutralization of minor actinides using special diluents (matrices) of nuclear fuel, inert to the formation of radioactive isotopes and characterized by increased radiation resistance, in particular, to the effects of fission fragments. Silicon nitride (Si3N4) is a promising candidate material for inert matrix fuel host to be used for transmutation of minor actinides via nuclear reactions. Radiation-induced changes in this material are subjects of extensive studies. Radiation defects induced by swift heavy ions (SHI) simulating fission fragments impact still remain less studied in comparison with neutron and conventional (low energy) ion irradiation. The purpose of this work is to study the swift heavy ion induced radiation effects in different crystalline structured silicon nitride using high-resolution transmission electron microscopy (HRTEM). Si3N4 samples were irradiated with Bi and Xe ions having energies ranging from 156 to 714 MeV and electronic stopping powers - from 6 to 35 keV/nm at the IC-100 and U-400 FLNR JINR cyclotrons and the DC-60 cyclotron at the IRC INP. The latent track parameters and threshold value of electron stopping power for track formation were found for amorphous and crystalline Si3N4. Experimental results are considered within the framework of the inelastic thermal spike (i-TS) model.

Speaker: Alisher Mutali (L.N. Gumilyov Eurasian National University, Nur-Sultan, Kazakhstan / G.N. Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Dubna, Russia / Astana Branch of the Institute of Nuclear Physics, Nur-Sultan, Kazakhstan)

10:30 Mechanical milling effect on structural and electrochemical properties of lithium-nickel-manganese-cobalt oxide cathode materials

Electrode materials microstructure modification is one of the promising methods for improving Li-ion battery performance (e.g. power, cycle rates). In cathode materials (materials for positive electrode) based on lithium-nickel-manganese-cobalt oxide (NMC) maximum charge/discharge currents are limited both because of low Li—ion diffusion values inside the grains of the material and its low electronic conductivity [1, 2]. Theoretically, current values can be increased by reducing particle size of the material [3]. As a result, the smaller the particle size, the shorter the lithium diffusion paths and the larger the surface area of the active material being in contact with the conductive additives and electrolyte [4, 5]. It is known that particle size reduction correlates well with electrochemical properties improvement for lithium-iron phosphate (LiFePO4) [6, 7], lithium-manganese phosphate (LiMnPO4) [8] and spinel (LiMn2O4) [9] cathode materials. The particle size effect plays an important role in the electrochemical performance of layered cathodes NMC for lithium-ion batteries. In particular, for such materials as LiNi0.50Mn0.50O2, LiNi0.33Mn0.33Co0.33O2 and LiNi0.40Mn0.40Co0.20O2, LiNi0.4Mn0.4Co0.18Ti0.02O2 the above property is presented in works [10, 11]. The authors showed that due to ultra-small particle size the large surface area of the active material led to losses in the energy consumption of the cathodes with accelerated degradation of the working surface and various side electrochemical reactions as causes. It was found [12] that besides the reducing the initial particle size to nano-size, several things occur, namely, layered structure disordering, transition metals reduction, and impurity phases formation. The most balanced capacitive and charge/discharge characteristics for layered cathode materials seem to be obtained with particles not exceeding 100 nm in size, submicron particles [10, 11]. From this point of view, high-energy planetary milling is still considered to be a route to gain particles of a given size.
It is known that structural and electrochemical properties of NMC materials depend drastically on conditions that preparation and synthesis were held under. Furthermore, it is rather difficult to systematize the effects obtained in different works because of various before measurement sample preparation conditions and the final result can be significantly affected via those factors. Nowadays there are no researches for the effect on the properties of series NMC cathode materials synthesized under similar conditions and caused by mechanical milling. Moreover, in such works, an accurate approach to characterizing the microstructure is of a great importance. It is necessary to separate the size effects from the effects associated with the crystal structure microdeformations and, accordingly, to reveal interrelations between various microstructural defects and electrochemical properties in the materials under study.
In this report we represent preliminary results obtained from a research for the crystal structure and microstructure effects in commercial NMC electrode materials caused by high-energy milling. Milling was carried out for 0, 4.5, 12, 24 and 72 hours and the content of nickel, manganese and cobalt in the studied samples was taken in the proportions of 8:1:1, 5:2:3 and 1:1:1. Methods that were used to analyze the structure of mechanically synthesized materials are as follows: scanning electron microscopy and two complementary diffraction methods - X-ray diffraction and high-resolution neutron diffraction. Data analysis was held via Rietveld and Williamson-Hall methods. Nonlinear dependence of particle size reduction on the time of mechanical action in a planetary mill as well as anisotropic change in the morphology of NMC particles during milling was revealed. Within the gained errors the atomic crystal structure changes were not detected for all NMC samples used in the experiments. Coin-cells of standard size 2016 with electrodes based on modified NMC powders in proportions of 85% active substance, 5% carbon black (C45) and 10% PVDF were prepared and electrochemical measurements were carried out by chronopotentiometry method. Data from electrochemical experiments contain information about the first three cycles in the galvanostatic mode at rates of 0.1C and 1C as well as the total number of successfully completed cycles. It is also important to note that the degradation rate of the modified NMC is monitored. Preliminary results obtained from experiments with NMC111 show that in comparison to original, not milled electrode material, the milled samples do operate with less capacity. In comparison to the unmilled sample, the capacity drop of about 60% for the sample milled for 72 hours was detected when the material was cycled on a rate of 0.1C. When the cycling rate was changed from 0.1C to 1C the capacity reduced by several orders of magnitude: 85.4 mAh/g vs 6.4 mAh/g for not milled samples, 84.5 mAh/g vs 2.9 mAh/g for the samples milled during 12 hours and 50.7mAh/g vs 0.03 mAh/g for 72 hour-milled samples. Explanation of these effects is being discussed. This work is carried out with the support of
the Russian Science Foundation, pr. No. 21-12-00261.

Literature:
[1] M. Yonemura, A. Yamada, Y. Takei, N. Sonoyama, and R. J. Kanno //J. Electrochem. Soc. - 2004. - 151. - A1352.
[2] C. Delacourt, L. Laffont, R. Bouchet, J. B. Leriche C.Wurm, M. Morcrette, J. M. Tarascon, and C. Masquelier // J. Electrochem. Soc. -2005. – 152. - A913.
[3] A. Yamada, S. C. Chung, and K. Hinokuma // J. Electrochem. Soc. - 2001.– 148. - A224.
[4] S. T. Myung, S. Komaba, N. Hirosaki, H. Yashiro, and N. Kumagai // Electrochim. Acta. - 2004. – 49. - 4213.
[5] C. H. Mi, X. B. Zhao, G. S. Cao, and J. P. Tu // J. Electrochem. Soc. - 2005.– 152. - A483.
[6] Bobrikov I.A., Balagurov A.M., Hu C.-W., Lee C.-H.,Chen T.-Y., Sangaa Deleg, Balagurov D.A. // J. Power
Sources. -2004. - 258. - 356.
[7] T.V.S.L. Satyavani, B. Ramya Kiran, V. Rajesh Kumar, A. Srinivas Kumar, S.V. Naidu // Engineering Science and Technology, an International Journal. - 2016. – 19, 1. – 40.
[8] J. Ni, Y. Kawabe, M. Morishita, M. Watada, and T. Sakai // J. Power. Sources. 2011. – 196. - 8104.
[8] H. Zhang, Y. Xu, and D. Liu // RSC. Adv. – 2015. – 5. – 11091.
[10] S. K. Martha, H. Sclar, Z. Szmuk Framowitz, D. N. Kovacheva, N. Saliyski, Y. Gofer, P. Sharon, E. Golik, B. Markovsky, and D. Aurbach // J. Power. Sources. – 2009.- 189. – 248.
[11] H. Sclar, D. Kovacheva, E. Zhecheva, R. Stoyanova, R. Lavi, G. Kimmel, J. Grinblat, O. Girshevitz, F. Amalraj, O. Haik, E. Zinigrad, B. Markovsky, and D. Aurbach // J. Electrochem. Soc. – 2009. -156. -A938.
[12] Taijun Pan, Judith Alvarado, Jian Zhu, Yuan Yue, Huolin L. Xin, Dennis Nordlund,4 Feng Lin, and Marca M. Doeff // J. Electrochem. Soc. – 2019. – 166, 10. - A1964.

Speaker: Ms Marina Donets (Lomonosov Moscow State University, Faculty of Physics; Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research)

AYSS_OCT_2021.pdf

10:45 Raman spectroscopy, neutron scattering and MD simulation combined study of cholesterol and melatonin effects in lipid bilayer

We have studied the effect of cholesterol and/or melatonin on the static and dynamical properties of DPPC and POPC-based phospholipid bilayers utilizing neutron scattering techniques and Raman spectroscopy. We report that cholesterol induced an increase in bilayer thickness, while melatonin induced a decrease in bilayer thickness in the three-component systems of lipid/cholesterol/melatonin. Commensurately, by evaluating the projected area of lipid, we demonstrate its decrease with an increasing concentration of cholesterol, and its increase with an increasing concentration of melatonin. The demonstrated condensing effect of cholesterol and the fluidizing effect of melatonin appear in an additive manner upon their mutual presence.
Raman spectroscopy is known as a very sensitive instrument for probing conformational changes manifested in vibrational spectra of biological samples under certain conditions. The analysis of the obtained Raman spectra for DPPC was done in the certain part of the fingerprint region, specifically 1030-1150 cm-1, as it is known to be sensitive to trans/gauche conformations. We evaluated spectral weights (i.e., integrated areas) of three dominant Raman bands of DPPC (1062 cm-1, 1096 cm-1, 1127 cm-1) for estimating the order/disorder dynamics in our systems.
As expected, based on the two-component systems of lipid/cholesterol or lipid/melatonin studied previously, we show the impact of cholesterol and melatonin being opposite and competitive in the case of three-component systems of lipid/cholesterol/melatonin. It has been revealed that the effect of cholesterol appears to prevail over that of melatonin in the case of structural properties of DPPC-based bilayers, which can be explained by its interactions targeting primarily the saturated lipid chains. As a result of our studies and evaluations of the trans / gauche conformations ratios, it was shown that the dynamics of the studied three-component lipid-cholesterol-melatonin systems demonstrates a balanced competing effect of the two additives used in this study.

Speaker: Yersultan Arynbek (JINR, INP, KazNU)

11:00 Simulation of changes in thermal conductivity of aluminum oxide irradiated with swift heavy ions

Thermal conductivity (TC) degradation of aluminum oxide induced by irradiation with swift heavy ions (SHI) at room temperature is studied and quantified with direct method of non-equilibrium molecular dynamics. The calculations were performed for an ideal crystal lattice, amorphous and irradiated states of aluminum oxide. Irradiated samples were described by the model of the track formation combining Monte-Carlo code TREKIS [1], describing the excitation of the electronic subsystem, with classical molecular dynamics of the lattice atoms [2]. Then these results were used as input data for simulation of thermal conductivity of irradiated state.
Simulation with direct method showed, that the obtained thermal conductivity of ideal alumina crystal is in good agreement with the experimental data from literature [3]. The calculated TC values for discontinuous crystalline tracks in irradiated alumina are also in good agreement with the experiment for low fluences (Time-Domain Thermal Reflectance method [3]). However, there are discrepancies between modeling and experiment in multiple track-overlapping regime. In order to solve this problem, Al2O3 was considered as layered system within multilayer thermal model including three regions: amorphous, near-surface damaged layer and discontinuous ion track region. This approach allowed us to describe the experimentally observed dependence of thermal conductivity of alumina on irradiation fluence. Obtained results reveal significant role of surface effects in Al2O3 in degradation of thermal properties under swift heavy ion irradiation.

References

[1] N.A. Medvedev, R.A. Rymzhanov, A.E. Volkov, Time-resolved electron kinetics in swift heavy ion irradiated solids, J. Phys. D. Appl. Phys. 48 (2015) 355303. doi:10.1088/0022-3727/48/35/355303.
[2] R. Rymzhanov, N.A. Medvedev, A.E. Volkov, Damage threshold and structure of swift heavy ion tracks in Al2O3, J. Phys. D. Appl. Phys. 50 (2017) 475301. doi:10.1088/1361-6463/aa8ff5.
[3] A. Abdullaev, V.S. Chauhan, B. Muminov, J. O’Connell, V.A. Skuratov, M. Khafizov, Z.N. Utegulov, Thermal transport across nanoscale damage profile in sapphire irradiated by swift heavy ions, J. Appl. Phys. 127 (2020) 035108. doi:10.1063/1.5126413.

Speaker: Aidos Akzhunussov (JINR)

11:15 Composite "track-etched membrane modified with chitosan and metal–organic framework” for heavy metal sorption

In the last time, the problem of water purification from dangerous substances is becoming more and more acute. A large number of studies are devoted to the extraction of heavy metals from aqueous solutions [1,2,3]. In addition, the extraction and concentration of valuable heavy metals from solutions is also of interest. The creation of solid adsorbents with high capacity and stability in the aquatic medium is a very important task. One of the promising types of adsorbents is metal-organic frameworks (MOF). MOFs are crystalline materials consisting of an infinite network of metal-ions, or metal-ion clusters, bridged by organic ligands through coordination bonds into porous two- or three-dimensional extended structures. Very few MOFs are used as adsorbents from aqueous solutions because most MOFs are unstable in aqueous medium [1]. In our work, Ni-MOF {[Ni(L-trp)(bpe)(H2O)]•H2O•NO3}n was synthesized (L-trp = L-tryptophan, bpe = 1,2-bis(4-pyridyl)ethylene). It is stable in an aquatic environment. With UV-Vis spectrometry, we investigated the properties of Ni-MOF in the process of ruthenium sorption from aqueous solutions of ruthenium chloride as model. Effects of pH, adsorbent dosage and contact time in Ru(III) sorption on Ni-MOF were studied in detail. The sorption capacity of the material was measured at different concentrations of ruthenium in solution (10, 25, 50, 100, 200, 300 mg L-1).
The possibility of efficient and convenient extraction of the adsorbent from the solution is significant. Most often, the sorbent is recovered by centrifugation or filtration, or using a magnet in the case of magnetic materials. Therefore, the number of works on the creation of magnetic composites based on MOFs is increasing [2]. Another interesting direction of the creation composite materials for adsorption is the infliction of MOFs on polymer substrates (membranes and fibers). Some researchers have proposed the use of MOFs as fillers in electrospun nanofibers [3]. But in this case a lesser region of the MOF particle is exposed to the bulk for adsorption. Another variant is self-assembly of the adsorbent on a substrate [4]. In this case, the formation of centers for the nucleation of adsorbent crystallites is desirable. This method was chosen in our work. A track-etched membrane, modified with chitosan, was studied as a substrate for the MOF. The membrane was received from Flerov Laboratory of Joint Institute for Nuclear Research (Dubna, Russia). The synthesis of Ni-MOF takes place under mild conditions that do not destroy either the membrane or the chitosan fibers. Only in the presence of chitosan MOF particles firmly adhere to the substrate. This is due to the structure of chitosan molecules, which can act as nucleation centers and increase hydrophilicity of the membrane. The synthesized materials were characterized by X-ray diffraction, scanning electron microscopy and thermal analysis. It was shown that the crystal structure and microstructure of pure MOF and MOF supported on the membrane are identical. In the future, we plan to study the adsorption properties of the obtained membranes coated with MOF particles. In case of successful work, these composites can become a basis of filters for water purification from heavy metals.

[1] N. Manousi, et al. Extraction of Metal Ions with Metal–Organic Frameworks // Molecules 2019, 24, 4605
[2] M. Babazadeh, et al. Solid phase extraction of heavy metal ions from agricultural samples with the aid of a novel functionalized magnetic metal–organic framework // RSC Advances 5 (26), 19884-19892
[3] J.E. Efome et al. Metal–organic frameworks supported on nanofibers to remove heavy metals // J. Mater. Chem. A, 2018, 6, 4550–4555
[4] L. Lv et al. Templating metal-organic framework into fibrous nanohybrids for large-capacity and high-flux filtration interception // Journal of Membrane Science 622 (2021) 119049

Speaker: Olga Ivanshina (Joint Institute for Nuclear Research (Russia))

11:30 The role of defects in graphene for removal of toxic compounds

Understanding the adsorption of pesticides and toxic gases on graphene has
high importance for their degradation and removal. In the present study, the
adsorption of different models of organophosphate pesticides (OPH3, OPF3,
SPH3 and SPF3) on perfect and defected graphene was examined by using the DFT method. Inspected systems were pristine, single-vacancy (SV), Stone-Wales (SW) and epoxy graphene. Pristine graphene exhibits great adsorption affinity towards OPH3 molecule, while it shows insignificant adsorption towards other examined species. The introduction of defects influences the reactivity of these molecules on the graphene surface. Among them, SV graphene showed the highest adsorption affinity for OPH3 and OPF3, while SW graphene showed the most suitable adsorption properties towards SPH3 and SPF3 molecules. The interaction between molecules and graphene was mostly physisorption except in the case of epoxy graphene where degradation of organophosphates occurred. This study suggests that graphene can be potentially used to remove environmental pollutants and pesticides' chemical degradation, while the surface chemistry of graphene should be carefully tailored for this application.

Speaker: Marko Jelić (Vinča Institute of Nuclear Sciences)

11:45 Isoscattering point in SANS contrast variation studies of core-shell nanoparticles

Core-shell nanoparticles are widely spread in advanced technologies. Small-angle neutron scattering (SANS) is actively used in their structural diagnostics [1,2]. Providing H/D isotopic substitution in the liquid carrier of magnetic fluids lets adjusting the neutron scattering length density (SLD) of the solvents in a frame of the contrast variation technique [3].
There are specific points at which the neutron scattering intensity from the liquid system is independent of the SLD contrast between dispersed particles and dispersing media. These points, q, are referred to as ‘isoscattering points’ [4]. q** is inversely proportional to the particle size. Usually, the nature of the isoscattering point is associated with the high symmetry of the nanoparticle shape and low polydispersity. Here we discuss the conditions for observing an isoscattering point for polydisperse core-shell structures, as well as additional possibilities of structural characterization via SANS based on this effect.
[1] Bica D. et al., Journal of Magnetism and Magnetic Materials. 311(1), 17-21 (2007).
[2] Avdeev M.V., Aksenov V.L., Physics-Uspekhi. 53(10), 971-993 (2010).
[3] Avdeev M.V., Journal of Applied Crystallography. 40(1), 56-70 (2007).
[4] Kawaguchi T., Crystallography Reviews. 10(3), 233-246 (2004).

Speaker: Dr Oleksandr Tomchuk (Taras Shevchenko National University of Kyiv, Faculty of Physics)

10:15 → 12:00 Nuclear Physics

https://jinr.webex.com/jinr/j.php?MTID=m23f10d08e276f37848aa98c276790793

10:15 INVESTIGATION OF γ-RAY SPECTROMETER BASED ON SCINTILLATION PHOSWICH-DETECTORS

A method for registering high-energy γ-rays using the array of 9xCeBr3-NaI(Tl) phoswich-detectors [1] is investigated. The technique makes it possible to identify high-energy γ-rays formed during the γ-decay of giant dipole resonances (GDR) from cascades of low-energy "yrast" γ-rays with a similar total energy.
The main characteristics of gamma-ray spectrometer: the energy resolutions ΔE, the total registration efficiency δγ and the registration efficiency at the peak of the total absorption δPEAK, depending on the energies Eγ of the registered γ-rays and on the distances to the source are presented. The measurements of the γ-spectrometer characteristics were carried out using the VME DAQ-system [2] by tagging γ-ray method. Complex forms of scintillation signals of phoswich-detectors were studied using digital (Mesytec MDPP-16) and analog (Mesytec MADC-32, MQDC-32) electronics [2]. Both approaches (analog and digital) made it possible to clearly separate the CeBr3 and NaI(Tl) components of scintillations. The characteristics of the γ-ray spectrometer in the Compton suppression mode are measured based on the analysis of the scintillation signal’s shapes. The experimental data were compared with the calculations (see Fig. 1) carried out by the Monte Carlo method of the GEANT4 program [3].

Here should be two figures. Due to no solution to add pdf or doc, I can send them to given e-mail.

Fig. 1. The total efficiency δTOTAL (left) and peak efficiency δPEAK (right) as a function of distance to γ-source 60Со. The measurements for tagging γ-rays with Eγ = 1173 keV.

1. https://scionix.nl/scintillation-detectors/ - website of the manufacturer of scintillation detectors Scionix;
2. https://www.mesytec.com/ - website of Mesytec;
3. https://geant4.web.cern.ch/support/download - GEANT4 (CERN).

Speaker: Zhassulan Zeinulla

10:30 PXI-compatible amplifier and preamplifier card for proportional gas counters

PXI-compatible card combining amplifier and preamplifier for proportional gas counters is presented. This PXI-compatible amplifier/preamplifier is developed for purpose of usage with proportional gas counter sensitive to 14.4 keV and PXI-based spectrometers developed on Palacký University in Olomouc [1], [2]. The card is based on Amptek A225 and Amptek A206 integrated circuits. It allows miniaturization of the spectrometric system, as the amplifier and preamplifier together are in form of one PXI card and thus built in the compact PXI-chassis. There is also no need for the additional power supply, as the developed card is powered by PXI connector from the backpane of PXI chassis. This study will deal with comparison of PXI-compatible amplifier/preamplifier board, amplifier/preamplifier board using same components but in form of stand-alone box and powered by lab power supply and other commercially available amplifiers and preamplifiers in the focus on the signal-to-noise ratio, MCA spectrum and quality and effect of Mössbauer spectrum.

References
[1] J. Pechousek and M. Mashlan, “Mössbauer spectrometer as a virtual instrument in the PXI/Compact PCI modular system,” Czechoslov. J. Phys., vol. 55, no. 7, pp. 853–863, Jul. 2005, doi: 10.1007/s10582-005-0087-x.
[2] J. Pechousek, R. Prochazka, D. Jancik, J. Frydrych, and M. Mashlan, “Universal LabVIEW-powered Mössbauer spectrometer based on USB, PCI or PXI devices,” J. Phys. Conf. Ser., vol. 217, no. 1, p. 012006, Mar. 2010, doi: 10.1088/1742-6596/217/1/012006.

Speaker: Pavel Kohout (JINR)

10:45 Separation efficiency and separation time of mass separator MASHA measured for radon and mercury isotopes

The discovery of the Super Heavy Elements (SHE) with atomic number Z=113-118 as well as new neutron excess isotopes of the elements with Z=104-112 was one of the outstanding scientific results of the last decades. These high priority experiments were carried out on the cyclotron U400 of the FLNR (JINR, Dubna, Russia). The synthesis of the new super heavy elements stimulated works on the development of methods of their identification by means of the technique called Isotope Production On-Line (ISOL). Thereto, in the FLNR there was designed and put into commissioning the mass separator MASHA - Mass Analyzer of Super Heavy Atoms. The uniqueness of this mass spectrometer consists in ability to measure "on line" the masses of the synthesized isotopes of the super heavy elements simultaneously with detection of their alpha decays and spontaneous fission.
The main characteristics of MASHA setup is the separation efficiency and separation time. To determine these parameters two experiments by using the complete fusion reactions $^{40}$Ar+$^{144}$Sm and $^{40}$Ar+$^{166}$Er, E$_{beam}$ = 5-7 MeV/n, were carried out. The experiments were carried out at the U400M cyclotron of the FLNR, JINR (Dubna). In the first experiment, the absolute cross sections of evaporation residua (radon and mercury isotopes) were obtained. In addition the absolute cross sections for p(xn) and $\alpha$(xn) reactions were also measured. The method of moving absorber made of ultra-thin aluminum foils (0.8 $\mu$m), where the reaction products were stopped, was used. The alpha decay of synthesized isotopes was detected by using silicon detectors. Energy resolution of alpha-radioactive isotopes was ~ 100 keV. Time moving of aluminum absorbers between two extreme positions was 0.3 s. The using of beam interruption method allowed to measure half-life of synthesized nuclei. As a result, the method allowed reliable identification of reaction products. In the second experiment, the excitation functions of the same reactions were measured with upgraded mass separator MASHA including the modernization of rotating target assembly, solid hot catcher, ECR-ion source, beam diagnostics and DAQ system. To register the products of nuclear reactions, a multi-strip silicon detector was installed in the focal plane of the mass separator.
By direct comparison of these results, the separation efficiency and separation time of evaporation residua were determined.

Speaker: Alena Kohoutova

11:00 One-dimensional detector for diffraction experiments at a synchrotron radiation beam

One-dimensional detector for time-resolved diffraction studies at a synchrotron radiation beam operating in photon counting mode is under development in the Budker Institute of Nuclear Physics Siberian Branch of Russian Academy of Sciences. The detector will allow to store the dynamics of diffraction process and to sort photons by their energy simultaneously. As a sensitive part we suppose to use microstrip silicon or GaAs sensor with strip pitch of 50 um coupled to the application specific integrated circuit (ASIC). The prototype of such ASIC has been developed. It contains a charge-sensitive preamplifier, a shaper with shaping time of 500 ns, four comparators that determine four thresholds in order to sort photons by their energy, four scalers and a readout shift register. The equivalent noise charge (ENC) is expected to be about 180 electrons. The prototype ASIC contains 8 such channels with different design options. At present, the front-end board with the ASICs has been assembled and is ready for testing. Development of the detector firmware and software is on the way.

Speaker: Anastasia Glushak

GlushakAA_One-dimensional detector for diffraction experiments at a synchrotron.pdf

11:15 Development of preparation method of intermetallic compounds thin films for high-power accelerator targets production

The invention of a new method to produce targets stable under prolonged intense irradiation conditions is very important for radiochemistry and nuclear chemistry. We suggest the method called “coupled reduction” which is based on the formation of the intermetallic compound layer. The novelty of our approach is to adapt this method for the preparation of high-power radioactive targets supplying the crucial properties for accelerator targets techniques. Nickel (Ni) was used as backing foil material, Palladium (Pd) and Europium (Eu) were used to get the intermetallic compound. For the preparation of such targets, at the first step, Pd as a diffusion layer was deposited onto the Ni backing foil by vacuum deposition. The target material Eu was electroplated by the molecular plating technique and then reduced in a flow of pure hydrogen at about 1200°C. The intermetallic compound layer and based on this compound target were analyzed by Scanning electron microscope, energy dispersive spectroscopy and radiography method. Details will be described in the conference.

Speaker: Mrs Elizaveta Melnik (JINR)

11:30 Experimental setup for elemental analysis using prompt gamma rays at research reactor IBR-2

The new experimental setup has been built at the 11b channel of the IBR-2 research reactor at FLNP, JINR, to study the elemental composition of samples by registration of prompt gamma emission during thermal neutron capture. The setup consists of a curved mirror neutron guide and a radiation-resistant HPGe high-purity germanium detector. The detector is surrounded by lead shielding to suppress natural background gamma level. The sample is placed in a vacuum channel and surrounded by a LiF shield to suppress the gamma background generated by scattered neutrons. This work presents characteristics of the experimental setup. An example of hydrogen concentration determining in diamond powder made by detonation synthesis is given and on its basis, the sensitivity of the setup is calculated being ~10µg.

Speaker: Mr Constantin Hramco

11:45 Compact neutron velocity selector for experiment on measuring reflection coefficient of very cold neutron VCN

In neutron physics experiments, it is very important to have a knowledge and determination of the velocity of the useful neutrons for carrying out a full-fledged experiment. To have a certain speed of slow neutrons, an experimental instrument is needed called a neutron velocity selector.
In the up-going experiments of the JINR FLNP group on the measuring of the reflection coefficient of very cold neutrons, the most important part is the neutron velocity selector [1]. Thus, for the purpose of this experiment, the goal is to create a new neutron velocity selector with high transmission and with good resolution, which is optimal for its use in experiments.
A neutron velocity selector is a rotating cylinder made of absorbing material with angular velocity and with am infinitely narrow helical slot cut along its surface so as to progress an angle in the cylinder length.
This work presents a theoretical calculation of a neutron velocity selector for a very cold neutron beam in the wavelength range of 30–160 A, as well as a geometry optimization procedure. The output wavelength and speed resolution are calculated. The effects of the divergence of the incoming beam are also estimated.

1. E.V. Lychagin, A.Yu. Muzychka, V.V. Nesvizhevsky, G. Pignol, K.V. Protasov, A.V. Strelkov. Storage of very cold neutrons in a trap with nano-structured walls // Physics Letters B 679 (2009) 186–190

Speaker: Kylyshbek Turlybekuly (FLNP JINR; The Institute of Nuclear Physics, Almaty;)

10:15 → 12:00 Theoretical Physics

https://jinr.webex.com/jinr/j.php?MTID=meb12aaca113321b28f8c123868a1ac0f

10:15 Energy dependent ratios of level-density parameters in superheavy nuclei

The nuclear level densities and level-density parameters in fissioning nuclei at
their saddle points of fission barriers, as well as those for neutron, proton, and alpha particle emission residues at the ground states are calculated for isotopic chains of superheavy nuclei with Z = 114 − 120. The calculations are performed with superfluid formalism using the single-particle energies obtained with the Woods-Saxon potential. The energy dependent level-density parameter ratios
are important for the estimation of the probabilities of de-excitation cascades via light particles emission in competition with splitting and thus for the determination of the survival probabilities. The influence of shell effects on energy dependence of the ratios of level-density parameters corresponding to residues of considered decay modes to those of neutron emission is studied. In the case of alpha decay, we identified the collective enhancement caused by cluster degrees of freedom to play an important role.

Speaker: Dr Azam Rahmatinejad (Joint Institute for Nuclear Research, Dubna, 141980, Russia)

Rahmati Nejad.pdf

10:30 Investigation of the spin-orbit strengths on the prediction of the closed shells for superheavy nuclei based on Two Center Shell Model

Using the microscopic-macroscopic approach based on the modified two-center shell model, ground-state shell corrections for even Z superheavy nuclei in the alpha-decay chains containing of A=295-300,302,304, Z=120 and the low-lying one quasiparticle spectra for 251Cf, 243Cm, 255Fm, 243Bk, and 251Es are calculated and compared with available experimental data. The calculations are successful in describing of low-lying spectra and reveal quite strong shell effects at Z = 120-126 and N = 184.

Speaker: Mrs Anna Bezbakh (JINR)

Bezbakh_Vls.pdf

10:45 Doubled geometries as generalized bimetric gravity models

The non-product noncommutative spectral geometry allows for several generalizations of the classical general relativity. In particular, doubled geometry models possesses features characteristic to bimetric gravity theories. In my talk I will describe such models for the pair of Friedmann–Lemaître–Robertson–Walker metrics and discuss stability of possible solutions in several cosmological scenarios.

Speaker: Arkadiusz Bochniak (Faculty of Physics, Astronomy and Applied Computer Science of the Jagiellonian University)

Doubled_FLRW.pdf

11:00 influence of external radiation on Josephson junction + nanomagnet system

We investigate Kapitsa-like pendulum effects in the magnetic moment dynamics of a nanomagnet coupled to a Josephson junction under external periodic drive. Generated by the Josephson junction and external drive magnetic field play the role of the oscillating force of the suspension point in analogy with the Kapitsa pendulum. The high frequency oscillations change the position of stability of magnetic moment. The magnetic field of the quasiparticle current of the Josephson junction determines the frequency dependence of the magnetic moment’s stable position. We obtain simple analytical formulas for the stable position of magnetic system both under external periodic drive and without it. The influence of external periodic drive on the voltage value of complete reorientation have been demonstrated.

Speaker: Kirill Kulikov (RF)

Kulikov_AYSS_2021.pdf

11:15 Description of the spectra of the lowest states for a chain of Zr isotopes based on the geometric collective model

The work is devoted to the description of the spectra of the lowest states and transition probabilities for the chain of zirconium isotopes $^{92−102}$Zr in the framework of the geometric collective model. As the mass increases, these isotopes undergo a transition from the spherical structure of the ground state to the deformed one; in $^{96}$Zr, the coexistence of spherical and deformed states is observed. The consideration is based on the collective Bohr quadrupole Hamiltonian, taking into account the triaxial degree of freedom. The selection of the potential parameters for each nucleus was carried out in such a way as to minimize the standard deviation between the available experimental data and the calculated values. The obtained potentials are close in shape to the potentials of the mean field models. Fairly good agreement with experimental data is observed. The deviations of the calculated data for isotopes with a spherical shape are analyzed.

Speaker: Evgenii Mardyban (Vasilevich)

Mardyban.pptx

11:30 Relativistic corrections to the form factors of three-nucleon nuclei.

Three-nucleon nuclei(3He and 3H) were considered in the framework of the relativistic covariant Bethe-Salpeter approach. The amplitudes of states of nuclei obtained from the solution of the Bethe-Salpeter-Faddeev equation were used to calculate the form factors of the triton and helion. The form factors of three-nucleon nuclei are calculated for the momentum transfer square up to 50 fm^-2 using various models of nucleon factors - a dipole fit, a relativistic harmonic oscillator model, and a vector dominance model. When calculating the form factors, relativistic corrections are taken into account, such as the Lorentz transformations of the arguments of the wave function and the propagator, a simple pole in the propagator, and the Lorentz transformations of the arguments of the wave function of the finite nucleus. The calculation results showed a significant contribution of relativistic corrections. The calculation using multi-rank potentials reproduces the diffraction minimum observed in the experimental data, while taking relativistic corrections into account improves the agreement with experiment.

Speaker: Sergey Yurev (JOINT INSTITUTE FOR NUCLEAR RESEARCH)

AYSS-21.pptx

11:45 $Z_N$ symmetry in $SU(N)$ gauge theories

Abstract: We study $Z_N$ symmetry in $SU(N)$ gauge theories in the presence of matter fields in the fundamental representation. To understand the $Z_N$ symmetry explicit breaking analytically we have considered a simple temporal one dimensional model which results from considering fields which are uniform in the spatial directions and the gauge fields with vanishing spatial components. To derive the free energy corresponding to the Polyakov loop, the partition function is evaluated for a given background of temporal gauge links where all the gauge links in the temporal direction are set to unity except the last link. The matter fields are then integrated out sequentially except for the two fields which are connected to the last link. We show that in the limit of large number of temporal sites the resulting free energy is independent of the $Z_N$ explicit breaking term i.e the explicit breaking of $Z_N$ symmetry vanishes, driven by dominance of the density of states. The present calculations leave out the effect of the spatial links and non-zero spatial modes of the matter fields. These modes are responsible for the Higgs and the chiral transitions, which are entropy driven. We argue that the spatial links as well as the spatial modes of the matter fields determine the boundaries separating regions where $Z_N$ symmetry is realised from the rest.

Speaker: Mr Sabiar Shaikh (The Institute of Mathematical Sciences, Chennai, India)

Sabiar_ayss2021.pdf

12:00 → 13:30 Lunch

13:30 → 15:30 Plenary session

https://jinr.webex.com/jinr/j.php?MTID=meb12aaca113321b28f8c123868a1ac0f

13:30 TBD

Speaker: Academician of RAS Grigory V. Trubnikov

14:30 Neutron investigations at JINR

Speaker: Dr. Valery N. Shvetsov

15:30 → 15:45 coffee break

15:45 → 17:45 Condensed Matter Physics

https://jinr.webex.com/jinr/j.php?MTID=m90f9278cba9f80b025fd3f9fc584ce38

15:45 Stabilizing Na0.7MnO2 cathode for Na-ion battery via surface coating

As sodium is abundant and inexpensive compared to lithium, Na-ion battery (NIB) has recently regained interest within the scientific community as a promising alternative to Li-ion battery for large-scale energy storage applications [1]. One of the challenges for commercialization of NIB is to develop cathode materials with high capacity and good stability. Among various NIB cathode materials reported to date, P2-type layered manganese oxide Na0.7MnO2 (NMO) has received much attention because of its high capacity (∼200 mAh g−1), superior rate performance and ease of synthesis [2]. In addition Mn is low-cost, earth-abundant and environmentally friendly element. However, rapid capacity decay upon repeated cycles restricts its practical application. This effect is consequence of Mn is Jan-Teller cation which provokes crystal structure distortion and instability. It was demonstrated that coating P2-Na0.7MnO2 with a P2-Na0.7Ni0.33Mn0.67O2 (NNMO) enhances its cycle stability due to doping process and stabilizing the hexagonal phase of the material.
In our work, we have synthesized a series of NMO and NNMO cathode materials. The samples were obtained by sintering from precursor powders at a temperature of 900°C in a stationary or in a flowing air atmosphere. By means of X-ray diffraction analysis it was shown that the material resulting composition strongly depends on the annealing conditions. Only during the synthesis in a stationary atmosphere, single-phase samples of mixed sodium-nickel-manganese oxide were obtained. At the same time, the structural disordering observed in the NMO material disappeared after the NMO coating with an admixture of sodium-nickel oxide. The synthesized materials were tested as part of model electrochemical cells.
In the future, we hope to conduct research on the doping of NMO with iron, since it is a more common and safe element than nickel.
This work is carried out with the support of the Russian Science Foundation, pr. No. 21-12-00261.

Speaker: Elena Ushakova (Joint Institute for Nuclear Research, JINR, Dubna, Russia)

16:00 Investigation of two-dimensional topological insulator candidate, Pt2HgSe3

In recent decades, it has become clear that the band structure of solids can be classified using the concept of topological invariants derived from geometry. This new classification of insulators divides them in conventional and topological insulators. Two dimensional topological insulators, or quantum spin-Hall insulators (QSH), are materials that do not conduct electrical current inside them, but have conductive edges protected by time reversal symmetry. Due to the properties of topological materials, edge states are created at the edges of the bulk material in such a manner, that they are able to conduct charge carriers without scattering or reflections, thus being very promising for electronic applications.
A major challenge in this area is the identification of wide band gap QSH materials that allow dissipationless electrical conduction by the edge states at room temperature. In the current research, I investigated a potential QSH material using various experimental tools, including ultra-high vacuum (5 * $10^{-11}$ Torr) and low temperature (9K) Scanning Tunneling Microscopy (STM), Atomic Force Microcopy (AFM) and confocal Raman spectroscopy. Using STM, I measured a band gap of the order of 100 meV, together with edge states characteristic for topological insulators. Because Jacutingaite ($Pt_2HgSe_3$) is a naturally occurring mineral, I was able to produce it in a stable normal atmosphere, as well as by exfoliation in thin layers of just a few atomic layers thickness.
The experimental work was performed in Budapest, in the framework of the Nanostructures Department, in the Institute of Technical Physics and Materials Science, part of the Centre for Energy Research Hungary. In this project, I achieved several new and scientifically groundbreaking results: I was the first to exfoliate $Pt_2HgSe_3$ to a thickness of 3 layers, I was the first to measure the Raman spectrum of the material, and I performed STM measurements for the first time, showing the band gap and the presence of electronic states along the edges. Continuing my work, my colleagues found during DFT calculations and further STM measurements that $Pt_2HgSe_3$ is a new and widely available platform for exploring the properties of topological two-dimensional electron systems. As a layered mineral, it can be exfoliated in a stable normal atmosphere in a thin layer with a thickness of a few atoms, and I have shown that it can be integrated into heterostructures with other two-dimensional materials. This expands the repository of 2D materials with a new topological insulator, and significantly improves the possibilities of manipulating 2D electronic systems by stacking layered materials. In addition, recent theoretical studies shed light on the possibility of superconductivity in doped $Pt_2HgSe_3$, which may provide an opportunity to investigate the coexistence of topological edge states with the superconducting phase in the same system. In summary, my work was the basis and contributed significantly to the publication of our scientific article in the journal Nano Letters.

Speaker: Mr Konrád Kandrai (Topology in Nanomaterials Research Group; Institute of Technical Physics and Materials Science; Centre for Energy Research; Eötvös Lóránd Research Network Hungary)

KANDRAI_Konrád-Investigation of two-dimensional topological insulator candidate, Pt2HgSe3(2)-converted.pdf

Signature of Large-Gap Quantum Spin Hall State in the Layered Mineral Jacutingaite

16:15 A study high pressure effect on the vibrational spectra of ranitidine hydrochloride

Ranitidine hydrochloride (C13H22N4O3SHCl) is an inhibitor of gastric acid secretion and used to block acid production in the stomach, for indigestion, acid reflux, heartburn, peptic ulcer and treatment of ZollingereEllison syndrome [1]. Polymorphs are different crystalline forms of a drug that may have different physico-chemical properties and biological activities. Since pharmaceuticals, at some stage during the manufacturing process, are organic crystalline materials, polymorphism may affect these products during new drug development and formulation [2,3].
Crystalline ranitidine is polymorphic and exists in two crystalline forms known as Form 1 and Form 2, and in several pseudopolymorphic forms [4]. The application of pressure can change the hydrogen bond array dramatically and could add an instability into the polymorphiс forms of the pharmaceutical compounds [5]. At ambient conditions the Raman spectra of C13H22N4O3SHCl corresponds to form II characteristic vibrational spectra [6].
The aim of this work was to analyze the vibrational spectra of the ranitidine hydrochloride by using Raman spectroscopy at pressures up to 11.2 GPa. The experiment was conducted in Frank Laboratory of Neutron Physics. Raman spectra at ambient temperature and pressures were collected using a LabRAM HR spectrometer (Horiba Gr, France) with a wavelength excitation of 633 nm emitted from He-Ne laser, 1800 grating, a confocal hole of 100 mm, and x50 objective.
At pressure P > 1.2 GPa, several significant changes in the Raman spectra were observed. These changes can indicate the new form of the ranitidine hydrochloride.
At P > 6.2 GPa a gradual broadening of most Raman lines was observed. The subsequent pressure increasing until P = 9.2 GPa followed by the disappearance of almost all Raman modes. Such a behavior corresponds to a gradual phase transition to the amorphous phase of the ranitidine hydrochloride.

References
1. Kichanov S. E. et al. A high pressure effect on the vibrational spectra of ranitidine hydrochloride //Journal of Molecular Structure. – 2020 – P. 128515.
2. R. Hilfiker, M. von Raumer, Polymorphism in the Pharmaceutical Industry: Solid Form and Drug Development, 1 ed., vol. 502, Wiley-VCH, 2018.
3. Agatonovic-Kustrin S. et al. Powder diffractometric assay of two polymorphic forms of ranitidine hydrochloride //International journal of pharmaceutics. – 1999. – vol. 184. – №. 1. – P. 107-114.
4. T. Madan, A.P. Kakkar, Preparation and characterization of ranitidine–HCl crystals, Drug Dev. Ind. Pharm. 20 (1994) 1571–1588.
5. E. Boldyreva, High-pressure polymorphs of molecular solids: when are they formed, and when are they not? Some examples of the role of kinetic control, Am. Chem. Soc. vol. 12 (2007) 1662e1668
6. T. Madan, A.P. Kakkar, Preparation and characterization of ranitidine-HC1 crystals, Drug Dev. Ind. Pharm. 20 (1994) 1571e1588,

Speaker: Saule Dyussembekova

Dyussembekova.pptx

16:30 Crystal and magnetic structure investigation of half-Heusler compounds MnNi0.9M0.1Sb (M = Ti, V, Cr, Fe, Co)

Half-Heisler magnetic intermetallic compounds of transition metals exhibit interesting physical properties such as magnetoresistance, ferromagnetic and antiferromagnetic magnetic states, and superconductivity. It is observed the shape memory effect and superelasticity with opportunity to control there phenomena by means magnetic field. It makes these compounds promising materials to apply for creation permanent magnets, elements of electronic devices and cooling technology.
To understand the formation of magnetic states in doped half-Heusler compounds based on MnNiSb it is necessary to correctly separate the contribution to the magnetic properties from the sublattices of nickel and manganese ions and to identify the relationship between the structural and magnetic properties of these materials.
In our work we present the results of investigation the crystal and magnetic structure of half-Heusler intemetallic compounds MnNi0.9M0.1Sb (M = Ti, V, Cr, Fe, Co) by means of neutron diffraction under normal conditions. Partial substitution of another transition element for nickel leads to a decrease in the magnetic moment of the Mn ions. Also MnNiSb, MnNi0.9Cr0.1Sb and MnNi0.9Fe0.1Sb compounds have been studied in the temperature range from 13 to 300 K. It has been found that the initial cubic structure F-43m and ferromagnetic phase remain in the investigated temperature range. New reflections corresponds to the antiferromagnetic phase have not been found.

This work have been supported by the Russian Foundation for Basic Research, project no. 20-52-04003 Bel_mol_a (Belarusian Foundation for Basic Research, project no. T21RM-029 ).

Speaker: Anton Rutkauskas (Joint Institute for Nuclear Research)

ASSY_2021_Rutkauskas.pdf

16:45 Neutron reflectometry with registration of the secondary radiation

Nowadays studying of proximity effects at the interface between two media are in focus of view. In particular it relates to the interface between superconductor and ferromagnet. Due to the mutual influence of ferromagnetism and superconductivity, because of the finite values of the coherence lengths, a significant modification of the magnetic and superconducting properties occurs. It appears, in particular, as changing of magnetization’s spatial distribution. It is important to establish the correspondence of the magnetic spatial profile (spatial dependence of magnetization) to the nuclear spatial profiles of the elements of the contacting media. To determine the spatial magnetic profile, the standard method of reflectometry of polarized neutrons is used, which makes it possible to determine the energy of the potential interaction of a neutron with a medium. At the interface between two media, the interaction potential is the sum of the interaction potentials of elements penetrating each other. Standard neutron reflectometry does not make it possible to establish which elements are associated with changes in the interaction potential and, in particular, in the magnetic profile. To determine the profile of the interaction potential of a neutron with individual elements, it is necessary to register the secondary radiation of the elements. At the moment, channels for recording charged particles, gamma quanta and spin-flip neutrons have been implemented at the REMUR spectrometer of the IBR-2 reactor in Dubna. Several tens of isotopes and magnetic elements are available for measurements.

Speaker: Mr Vladimir Zhaketov (Joint Institute for Nuclear Research)

AYSS_2021_Zhaketov.pptx

17:00 Determination of the second critical magnetic field of superconductors in the model for a system with two states

In this paper, we consider the determination of the second critical magnetic field of superconducting materials based on the model of splitting of energy levels in a magnetic field for a system with two states. The obtained dependence of the second critical field on the energy gap of superconductors is in good agreement with experimental data for superconducting alloys, metals, amorphous films, and some nitrides.

Speaker: Armen Dovmalov (National Research University "MPEI", Moscow, Russia)

17:15 A model of the conductivity of composite materials

The aim of the work is to investigate the dependence of resistance on temperature for composite materials with a dielectric matrix and conductive filler. The problem of using these materials is the not fully investigated nature of the conductivity from temperature.
The paper calculates the dependence of the resistance for a composite material with a dielectric matrix and a conductive filler on the temperature using various methods: the WKB approximation, the estimation through the coefficient of passage of a particle in a rectangular potential barrier. The obtained results were based on the quantum mechanical theory of tunneling. But the currently available models cannot fully describe these dependencies.
A qualitative model is proposed that describes the dependence of the resistance of a composite material taking into account various parameters: the coefficient of linear expansion, the difference between the energy of the particle and the energy of the potential barrier, the particle size, the distance between the particles. The qualitative dependences of the resistance of the composite material on the temperature when these characteristics change are presented. It is established that when the coefficient of linear expansion of the matrix decreases (for example, when replacing a substance in a composite), the resistance value decreases. As the distance between the composite particles increases, the sample resistance also increases.
The obtained results can be used to create a unified model describing the nature of the change in the resistance of a composite material with a change in temperature.

Keywords. Percolation theory, tunnel effect, potential barrier, dependence of the resistance of a composite material on temperature, WKB approximation.

Speaker: Ms Darya Babyshkina (National Research University "MPEI", Moscow, Russia)

17:30 Effects of γ- Irradiation on High-Density Polyethylene/SiO2 Polymer Nanocomposite Films

The effects of gamma irradiation on the structural, morphological and thermal properties of high-density polyethylene (HDPE) based nanocomposites (HDPE/%SiO2) are discussed in the work. The main objective and significance of the proposed research is to develop a multifunctional hybrid structure that can provide efficient radiation shielding and at the same time can provide excellent structural properties.
Polymer nanocomposite materials are manufactured commercially for many diverse applications such as isolation materials, aerospace components, automo- biles, etc. In the field of nanotechnology, polymer based nanocomposites have become an important area of current research and development. The addition of inorganic spherical nanoparticles to polymers allows the modification of the polymers physical properties as well as the implementation of new features in the polymer matrix. These composites show unique properties combining the advantages of the inorganic fillers like the rigidity, high thermal stability, and mechanical property with the processability, flexibility, and ductility of the organic polymers [1, 2, 3].
Polymer nano-composite films of high density polyethylene matrix (HDPE+%SiO2) were obtained by thermal pressing (under a pressure of 15 MPa) at a temperature 165 °C, followed by rapid cooling in water-ice system. As a filler it has been used an amorphous silica dioxide α-SiO2 (Sky Spring Nanomaterials, Inc. Houston, USA) with 20 nm size of spherical particles, specific surface area of S=160 m2/g and density of 2,65 g/sm3 [3]. The nanocomposite films were irradiated by γ-ray radiation. The irradiation was performed at room temperature by g-radiation 60Со isotope source on the facility РХ-γ-30 (ANAS Institute of Radiation Problems, Baku, Azerbaijan). The samples were subjected to various irradiation doses from 100 kGy to 500 kGy. The dose rate was 2.7 kGy/h during the irradiation [4]. Small-angle X-ray scattering (SAXS), small-angle neutron scattering (SANS), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) have been implemented to characterize nanoparticles behavior in the matrix of high-density polyethylene (HDPE).
The effects of gamma irradiation on the structural, morphological and thermal properties of this particular composition were systematically investigated and conclusions were drawn.
The nano-SiO2 filler causes strong interfacial interactions into HDPE polymer matrix. The nanoparticles lead to higher crystallization rate of HDPE. The lamellar thickness and the degree of crystallinity increase with increasing the nano-SiO2 filler loading. The degree of crystallinity, and crystallite sizes (both HDPE and the composite) increased with increasing of irradiation dose.
The polymer crystallinity increased as a consequence of the polymer chain alignment due to the crosslinking upon γ- irradiation. The enhancement of β-phases occurred due to the presence of hydrogen bonding that promoted crosslinking in the crystalline region upon gamma irradiation.
SEM results revealed that nano-SiO2 particles aggregates were in general distributed homogeneously. It was found that the nano-SiO2 aggregates are evenly located in the polymer matrix and their surface roughness and fractal character are determined by their initial state in the powders. DSC results showed that the silica nanoparticles decrease the melting temperature of composite but increase the crystallization temperature. Moreover, the structural and thermo-physical analysis showed that the core materials can retain the structural integrity after they are exposed to the highly gamma radiation.
The results obtained for radiation shielding parameters of HDPE/SiO2 nanocomposite films were found to be more promising and efficient for radiation protection against gamma-ray. In summary, our studies suggest that gamma irradiation can be used for improving the functional properties of polymer–ceramic composites, which are of technological importance in various fields.

Acknowledgements: The work was supported by the JINR-Romania Cooperation Programme Project of 11.05.2021 Order No. 366/49.

 References

[1] Shadpour Mallakpoura, Mina Naghdi, Polymer/SiO2 nanocomposites: Production and applications, Progress in Materials Science 97 (2018) 409-447.
[2] Dong Won Lee, Bok Ryul Yoo, Advanced silica/polymer composites: Materials and applications, Journal of Industrial and Engineering Chemistry 38 (2016) 1-12.
[3] A.A. Nabiyev, Influence of nanoparticle weight fraction on morphology and thermal properties of HDPE/SiO2 composite film, Eurasian Journal of Physics and Functional Materials 4 (1) (2020) 38-49.
[4] A.A. Nabiyev, A. Olejniczak, A. Pawlukojc, M. Balasoiu, M. Bunoiu, A.M. Maharramov, M.A. Nuriyev, R.S. Ismayilova, A.K. Azhibekov, A.M. Kabyshev, O.I. Ivankov, T. Vlase, D.S. Linnik, A.A. Shukurova, O.Yu. Ivanshina, V.A. Turchenko, and A.I. Kuklin, Nano-ZrO2 filled high-density polyethylene composites: structure, thermal properties, and the influence γ-irradiation, Polymer Degradation and Stability 171 (2020) 1-12.

Speaker: Asif Nabiev (JINR, LNF)

15:45 → 17:45 Nuclear Physics

https://jinr.webex.com/jinr/j.php?MTID=m23f10d08e276f37848aa98c276790793

15:45 YDA C++ PROGRAM PACKAGE FOR OPERATING WITH A NEW ANALOG SPECTROMETER OF THE DUBNA GAS – FILLED RECOIL SEPARATOR#2 INSTALLED AT MAIN FLNR DC-280 CYCLOTRON IN HEAVY ION INDUCED NUCLEAR REACTIONS

YDA (Yury&DAstan) Builder C++ PC based code has been developed. It allow to provide a data acquisition using 48x128 DSSSD(Double Side Silicon Strip Detector) detector and multi - wire pentane filled low pressure gaseous detector [1]. Main specific of the developed program package is to use flexible real-time algorithms to provide in-fact background free conditions for ultra-rare alpha decays registration [2,3]. Three scenarios of these algorithms are under consideration. Two of them deal with the relatively low rate of beam stops, whereas the third one corresponds to high beam stop rate. First results of application of YDA code are presented too. Electronics modules, operating together with YDA code are considered in brief too as well as the programs to visualize the experimental data [4]. Programs to test electronics modules are also under consideration.

Speaker: Mr Dastan Ibadullayev

Ibadullayev_report_AYSS-2021.pptx

16:00 Study of the formation and decay properties of neutron-deficient isotopes No

In the FLNR JINR at the kinematic separator SHELS the new neutron-deficient isotope $^{249}$No was synthesized for the first time in the complete fusion reaction $^{204}$Pb($^{48}$Ca,3n)$^{249}$No. Using the GABRIELA detection system, the new isotope was identified through genetic correlations with the known daughter and granddaughter nuclei $^{245}$Fm and $^{241}$Cf , and new activity has an energy E$_{\alpha}$ = 9129 keV and half-life T$_{1/2}$=38.3(2.6) msec. An upper limit of 0.2% was evidenced for the fission branch of $^{249}$No. Correlation events of the $^{249}$No alpha activity with subsequent alpha decays of energy 7728(20) keV and half-life T$_{1/2}$=$0.94_{-0.29}^{+0.76} min $ provided a firm measurement of the electron-capture branch of $^{245}$Fm to $^{245}$Es. The production cross section was found to be σ(3n)=0.47(3) nb at a mid-target beam energy Elab = 222.2 MeV, which corresponds to the maximum of the calculated excitation function. The excitation function for the 1n, 2n and 3n evaporation channels was measured.

Speaker: Mereigul Tezekbayeva (FLNP, JINR)

Tezekbayeva. Nuclear physics. 12.10.21.pptx

16:15 Study the Compton scattering of entangled annihilation photons.

In this work the study of Compton scattering of annihilation gammas in different polarization states is presented. The pairs of annihilation gammas are acquired as a result of positron-electron annihilation process. Polarization planes of two annihilation gammas are orthogonal to each other. However, the polarization of each photon in pair is indefinite. If one of the photons of the pair interacts with matter, the entanglement of the pair is broken and the pair becomes decoherent with determined polarization states of each gamma. Because Compton scattering depends on the polarization of the incident gamma, the scattering kinematics of entangled and decoherent pairs may differ significantly. The supposed difference is to be used in PET imaging. The experimental setup for the measurements of annihilation photons in different polarization states is discussed. It consists of two arms with 16 Compton polarimeters in each arm. The first results of the azimuthal correlations of the scattered photons are presented.

Speaker: Alexander Strizhak (INR RAS)

Strizhak - AYSS_2021.pdf

16:30 Elastic and inelastic scattering of 14.1 MeV neutrons on $^{12}$C

As part of the TANGRA project [1], we had measured angular distribution of $\gamma$-quanta, arising from the reaction of inelastic scattering of 14.1 MeV neutrons on the $^{12}$C nucleus [2]. Due to the properties of $^{12}$C, the information on its nuclear level structure that can be obtained by the registering $\gamma$-rays from the $^{12}$C(n,n'$\gamma$) reaction is very limited. It was decided to register the probe particles, neutrons, instead of $\gamma$-quanta in the hope of additionally studying the second ($0^+_2$, 7.65 MeV) and third ($3^-_1$, 9.64 MeV) excited states of $^{12}$C. The Hoyle state at 7.65 MeV is of particular interest in this respect because of its importance for the description of nucleosynthesis [3].

The angular distributions of neutrons scattered on carbon nuclei were measured with the TANGRA facility using tagged neutrons and time-of-flight methods. The data obtained were compared with results from previous experiments on the scattering of 114 MeV neutrons by $^{12}$C. Optical model
calculations (with coupled-channels approach), carried out using TALYS 1.9 nuclear reaction code [4], were used to describe the experimental data.

1. Project TANGRA, http://flnph.jinr.ru/en/facilities/tangra-project
2. D.N. Grozdanov et al.,Yadernaya Fizika, 81, 548 (2018)
3. M. Freer, H.O.U. Fynbo, Prog. Part. Nucl. Phys., 78, 1 (2014)
4. A.J. Koning and D. Rochman, Nucl. Data Sheets, 113, 2841 (2012)

Speaker: Ilya Dashkov (JINR, MSU SINP)

Dashkov_AYSS-2021.pdf

16:45 Very Cold Neutron Source Based on Nanodiamond Reflector

Neutrons can be an instrument or object in many fields of research. Major efforts all over the world are devoted to increasing the range of useful neutrons towards smaller energies. However, the progress in the field is limited by the severe decrease of the flux of available slow neutrons, as well as the efficiency of the delivery of such neutrons to experimental installations. The properties of neutron reflectors cause this dramatic decrease of slow neutron flux. Independently of the choice of materials, their evident common feature is that they are composed of atoms separated by distances of ~0.1 nm. As soon as the neutron wavelength reaches this value, neutrons penetrate through the reflector and are lost. This is equally relevant for nuclear research reactors, neutron spallation sources, compact accelerator-driven neutron sources, and others. In this context, neutron reflectors play a key role because they improve the performance of neutron sources and delivery systems in an economical and efficient way.

For slow neutrons, powders of detonation nanodiamond provide exceptionally good reflecting performance due to the combination of enhanced coherent scattering and low neutron absorption. This work reflects the current state of research of the nanodiamond reflectors for very cold neutrons. We will describe the application of a nanostructured reflector for the directional extraction of neutrons, as well as the experimental results and calculations. The concept of a low-energy neutron source based on such a reflector will be discussed. We will present the efficiency estimation for the developing prototype of a very cold neutron source.

This research is funded by grants RFFI-18-29-19039, CREMLINplus (grant agreement 871072), and the JINR grant for young scientists №21-402-06.

Speaker: Dr Alexander Nezvanov (Frank Laboratory of Neutron Physics, JINR)

FIN_NEZVANOV_AYSS-2021_presentation.pdf

17:00 A new high-efficiency radon registration method

Radon is a naturally occurring noble radioactive gas formed by the decay of radioactive chains of thorium and uranium. Radon and its daughter decay products are being increasingly studied, and their background contribution to low-background experiments for neutrino studies, dark-matter particle searches and other experiments requiring low-background conditions is also being investigated.

A new method of radon registration developed at the JINR DLNP will make it possible to correct a number of drawbacks of existing methods. Based on the proposed method, a compact radon detector with an expected sensitivity level of ~ 1 $mBq/m^3$ of radon in air has been created, which will allow efficient evaluation of the concentration of radon and its daughter products.

Speaker: Mr Konstantin Shakhov (JINR)

15:45 → 18:00 Theoretical Physics

https://jinr.webex.com/jinr/j.php?MTID=meb12aaca113321b28f8c123868a1ac0f

15:45 Specific features of light halo nuclei in interaction with α-particles

In recent years, the study of light weakly bound nuclei has not become less interesting due to the development of both experimental facilities and theoretical approaches. The nucleus 9Be having Borromean structure was the subject of study on its manifestation of cluster in direct nuclear reactions [1]. In particular, it was found that in the 9Be(d,α)7Li nuclear reaction the 5He heavy cluster is transferred mainly simultaneously, and the contribution of its sequential transfer is an order of magnitude lower. The importance of taking into account the mechanism of sequential transfer of the n–p system was revealed. Based on these observations, it was concluded that the 9Be nucleus may have cluster structure.
There is a need further broaden the theoretical research method, supposed in Ref. [1], with the nuclei 6He and 6Li. The experimental data on elastic scattering of α-particles by 6He and 6Li demonstrate significant growth of cross section at backward angles. Such kind of behaviour is characterized by contribution of the elastic transfer channel [2, 3].
The study of this work is based on the three body wave function using the Gaussian basis [4]. It worth to note that the three body model excludes the Pauli forbidden states by means of the method of orthogonalizing pseudo-potentials [5]. The analysis based on the CRC calculations shows that the major contribution to the elastic transfer cross section is resulted from the di-nucleon transfer channel, whereas the sequential transfer is one order of magnitude lower.

1.Urazbekov, B. A., et al. Journal of Physics G: Nuclear and Particle Physics 46.10 (2019): 105110.
2. Oganessian, Yu Ts, V. I. Zagrebaev, and J. S. Vaagen. Physical Review C 60.4 (1999): 044605.
3.Tanihata, Isao, Herve Savajols, and Rituparna Kanungo. Progress in Particle and Nuclear Physics 68 (2013): 215-313.
4. Kukulin, V. I., and V. M. Krasnopol'Sky. Journal of Physics G: Nuclear Physics 3.6 (1977): 795.
5. Kukulin, V. I., and V. N. Pomerantsev. Annals of Physics 111.2 (1978): 330-363.

Speaker: Bakytzhan Urazbekov (JINR)

16:00 Geometrical models of relativistic spinning particles in d=3 Minkowski space

The model of classical spinning particle is considered such that quantization of classical model leads to an irreducible representation of the Poincaré group. The class of gauge equivalence of classical particle world lines is shown to form a 2-dimensional world sheet in 3-dimensional Minkowski space, irrespectively to any specifics of classical model. For massive particles, the world sheets are circular cylinders with timelike axes. For massless particle with continuous helicity, the world sheets are parabolic cylinders with lightlike axes. The radius of circular cylinders and the focal length of parabolic cylinders are determined by representation. The position of the world sheet in Minkowski space is determined by momentum and total angular momentum of the particle. Proceeding from the fact that the world lines of irreducible classical spinning particle are cylindrical curves, while all the lines are gauge equivalent on the same world sheet, we deduce a differential equation describing the dynamics of model. The equations of motion are purely geometrical, and they do not involve any variables except the derivatives of space-time coordinates. The geometrical equations of motion are non-Lagragian, but they admit the equivalent second-order formulation involving an auxiliary variable. The second-order formulation agrees with a previously known spinning particle model. The problem of inclusion of consistent interactions with a general electromagnetic field is considered for massive particles.

Speaker: Ivan Retuntsev (Tomsk State University)

Retuntsev_tp.pdf

16:15 Nonleptonic decay of the \Lambda hyperon

We systematically study two-body nonleptonic decays of light lambda hyperon
with account for both short and long distance effects. The short distance effects are induced by five topologies of external and internal weak W ± exchange, while long distance effects are saturated by an inclusion of the so-called pole diagrams with an intermediate 1/2+ and 1/2− baryon resonances.
The contributions from 1/2+ resonances are calculated straightforwardly by account for nucleon and Σ baryons whereas the contributions from 1/2+ resonances are calculated by using the well-known soft-pion theorem in the current-algebra approach. It allows to express the parity-violating S-wave amplitude in terms of parity-conserving matrix elements. From our previous analysis of heavy baryons we know that short distance effects induced by internal topologies are not suppressed in comparison with external W -exchange diagram and must be included for description of data. Here, in the case of Λ decays we found that the contribution of external and internal W -exchange diagrams is sizably suppressed, e.g., by one order of magnitude in comparison with data, which are known with quite good accuracy. The major role to get consistency with experiment play pole diagrams.

Speaker: Жомарт Тюлемисов (ОИЯИ)

16:45 QCD equation of state at non-zero magnetic field using Dual QCD formulation

The QCD equation of state in presence of non-zero external magnetic field is studied using Dual QCD formulation. A Dual QCD formulation is constructed in terms of dual gauge potentials which takes into account the local as well as the topological structure of the color gauge group into its dynamics. The dynamical configuration of the resulting dual QCD vacuum and its flux tube configuration have been investigated for analyzing the non-perturbative features of QCD. Thermodynamic observables including the pressure, energy density, entropy density and the speed of sound are presented as functions of the temperature and the magnetic field. The temperature dependence of these quantities confirms that the transition temperature is reduced with magnetic field. Furthermore, the temperature dependence of magnetization verifies the conclusion that the QCD matter has paramagnetic properties near and far above the critical temperature. The behavior of the speed of sound suggests that the deconfinement transition temperature is lowered as the magnetic field grows.

Speaker: Garima Garima Punetha (Govt Post Graduate College Berinag Pithoragarh)

AYSS2021.pdf

17:00 Generalized BMS algebra at timelike infinity

BMS (Bondi-Metzner-Sachs) group (and its various generalizations) at null infinity has been studied extensively in the literature as the symmetry group of asymptotically flat spacetimes. The intricate relationship between soft theorems and the BMS symmetries has also motivated the definition of such asymptotic symmetries to timelike infinity [M. Campiglia, Null to time-like infinity Green’s functions for asymptotic symmetries in Minkowski spacetime, J. High Energy Phys. 11 (2015) 160.JHEPFG1029-847910.1007/JHEP11(2015)160]. Although the vector fields that generate the (generalized) BMS algebra at timelike infinity were defined in the literature, the algebra has not been investigated. In this paper. we fill this gap. We show that the supertranslations and vector fields that generate sphere diffeomorphisms close under the modified Lie bracket proposed by Barnich and Troessaert [Aspects of the BMS/CFT correspondence, J. High Energy Phys. 05 (2010) 062.JHEPFG1029-847910.1007/JHEP05(2010)062].

Speaker: Arpan Kundu (The Institute of Mathematical Sciences, Chennai)

Arpan_Kundu_AYSS_21.pdf

17:15 Reconstruction of the topological band structure in the Hofstadter-Hubbard model

The new approach based on the Cluster Perturbation Theory was applied to the Hubbard model to reveal the effect of electron-electron interaction on the topological band structure.
In contrast with the all existing approaches based on mean field approximation our technique allows to obtain the qualitative changing in the structure of Hofstadter butterfly in the presence of Coulomb repulsion.
By taking into account a strong correlation in the more accurate way we can imply both: the regular behaviour of the Chern numbers and the more subtle splitting of the Chern bands induced by electron-electron interaction.
Such splitting can be interpreted as a signature of fractional Chern regime is typical for strongly correlated topological phases.
It was shown that the critical value of the Coulomb repulsion $U_c$ inducing the Mott transition depends on magnetic flux.
Moreover, the Mott insulating phase can be closed and reopened by increasing the value of magnetic field.

Speaker: Ilya Ivantsov (BLTP JINR.)

OMUS2021.pdf

17:30 Nucleon density distributions and diabatic potential

In order to calculate potential energy of two reacting heavy ions different methods are applied. The folding procedure with effective nucleon-nucleon interaction and effective internucleus potentials are widely used [1].
In this report the calculations of diabatic potential energy are carried out for spherical even-even nuclei with Z, N ≥ 8. Potential is obtained with internucleon Migdal forces [2] folded with density distribution that is chosen as a two-parameter Fermi-distribution. Special attention is paid to the choice of nucleonic density parameters: half-density radius and diffuseness. Finally, gained results are compared with the proximity potential [3] and Bass potential [4].
1. V. Zagrebaev et al. // Phys. Part. Nucl. 2007. V. 38. P. 469.
2. A. B. Migdal. The Theory of Finite Fermi-Systems and Properties of Atomic Nuclei, 2-nd ed. (Nauka, Moscow, 1983) [in Russian].
3. Blocki J. et al. // Ann. Phys. (N.Y.). 1977. V. 105. P. 427.
4. R. Bass. Nuclear Reactions with Heavy Ions. Berlin: Springer, 1980.

Speaker: Makar Simonov (Moscow State University)

Simonov_AYSS21.pdf

17:45 Confinement phenomenon in gauge theories: from 2d sigma models to non-Abelian strings

Confinement phenomenon in QCD has been of great interest to theoretical physics for more than five decades. This phenomenon can be crudely described as the absence of free quarks (or other colored particles) in the physical spectrum. Thus formulated, confinement may seem simple at first sight, but to anyone who has studied this phenomenon one thing is clear: the picture of confinement in gauge theories is far from being obvious and complete.

In order to understand confinement in QCD, there has been attempts to look at some simpler (or even solvable) models that exhibit a similar phenomenon. One may mention, for example, two-dimentional $\mathbb{CP}$ sigma model, three-dimensional Polyakov confinement, four-dimentional Abelian Higgs model. However the particular mechanism of confinement in each of these scenarios seems to be unique and unlike the others.

In this talk we are going to review some of these topics. We will discuss how non-Abelian strings that emerge in supersymmetric cousins of QCD tie together some of these concepts.

Speaker: Mr Evgenii Ievlev (Petersburg Nuclear Physics Institute)

ievlev_talk_AYSS_v01_15min.pdf

19:00 → 22:00 Banquet. Cafe Dolcetto. Kunaev street 114, Almaty

Wednesday 13 October

10:00 → 10:15 coffee break

10:15 → 12:00 Applied research

https://jinr.webex.com/jinr/j.php?MTID=m23f10d08e276f37848aa98c276790793

10:15 SRTIO3 BASED PHOTOCATALYSTS FOR HYDROGEN PRODUCTION

Today, the global growth in energy demand has led to an active development of research in the areas of its production, storage, and use. The progress achieved in energy production technologies is not sufficient to fully meet the existing demand. The dwindling reserves of fossil fuels have prompted significant efforts to explore the use of hydrogen (H2) as a clean energy source. The use of H2 can solve the problems of depletion, pollution, and climate change. One of the technologies for the production of H2 is the photocatalytic splitting of water, the reserves of which are abundant on Earth.
The paper presents experimental data on the production of hydrogen by synthesized photocatalysts based on SrTiO3. Their physical and chemical properties have been investigated.
The objectives of the study are to obtain efficient photocatalytic cells with immobilized and suspended photocatalysts based on SrTiO3 with the addition of metal particles, followed by the study of the morphology of their surfaces and photocatalytic activity for hydrogen evolution. The main parameters for the preparation of photocatalytic cells with immobilized and suspended photocatalysts based on SrTiO3 with the addition of iron, copper and chromium particles have been investigated and determined. The thickness of the photocatalytic layer for fibers based on SrTiO3 with the addition of iron, chromium and copper particles for photocatalytic cells with an immobilized photocatalyst was studied, and the surface morphology of the formed photocatalyst layer was also studied. The rates of photocatalytic hydrogen evolution were investigated during the decomposition of water into hydrogen and oxygen under the action of ultraviolet (UV) radiation (40 W) for 24 hours using photocatalytic cells with immobilized and suspended photocatalysts.
The optimal parameters of the process of photocatalytic decomposition of water using photocatalysts based on SrTiO3 with the addition of metal particles using photocatalytic cells with immobilized and suspended catalysts have been determined.

Speaker: Adelya Kenzhebayeva

10:30 Determination of the elemental composition of archaeological ceramics found on the territory of Kazakhstan, by nuclear-physical methods and statistical analysis of the results.

The Neutron Activation Analysis (NAA) Group at the IREN research facility, Frank laboratory of neutron physics (FLNP) JINR do determination of the elemental composition of samples of different origin. Several methods are used for experiments, including neutron activation and X-ray fluorescence (XRF) analysis. Investigation of the elemental composition of 17 ceramics pieces found on the territory of Kazakhstan with statistical processing of the results was carried out in cooperation with the al-Farabi Kazakh National University. The samples were irradiated using the IBR-2 reactor and the IREN facility for NAA. A pneumatic transport system at the IREN facility was used to determine short-lived isotopes, while the IBR-2 reactor – medium- and long-lived isotopes. The spectra of the induced activity were measured by the HPGe detector Canberra GC4018 with a relative efficiency of 40%. The spectra were processed using the Genie-2000 software. The calculation of the detected elements mass fraction was done using the "Mass fractions" software. A Bruker S6 JAGUAR wave dispersive spectrometer was applied for XRF. The standardless SMART-QUANT WD method of analysis was used for measurements, the spectra were processed in the SPECTRA-ELEMENTS software. 38 elements were found using NAA, and 14 – using XRF. Statistical analysis of the data was done using the R software. Assumptions were made about the places of origin of the ceramics as a result of the experiment.

Speaker: Valerij Lobachev (FlNP)

10:45 Heating time and concentration of Pt influence on Fe-Pt nanoparticles properties: structure, morphology and hysteresis

L10 FePt is expected to exhibit excellent hard magnetic properties even when its size is as small as 3 to 4 nm, due to its large magnetic anisotropy. Therefore, much attention has been placed on fabrication and magnetic properties of nanostructured L10 FePt both from scientific and technological interests. In this work, FePt nanoparticles were obtained by pulsed plasma in liquid method from FePt – alloy in different content of Pt. further the FePt nanoparticles were annealed at different temperatures and transformed into L0 type. Crystal structure, morphology and hysteresis of the nanoparticles were studied using X-ray diffraction, HR-TEM and VSM analysis.

Speaker: Dr Zhazgul Kelgenbaeva (I. K. Akhunbaev Kyrgyz State Medical Academy)

11:00 Development of a multi-channel power supply for the TAO and DUNE experiments

Modern photodetectors, such as silicon photomultipliers (SiPM), are widely used in high-energy physics. In particular, for the near detector of the JUNO experiment, it is planned to use ~250,000 SiPMs, which will be grouped into matrices (~4000 pcs). These photodetectors will be used to register the light that is emitted as a result of the interaction of neutrinos and the detector's scintillator. Also, SiPMs is planned to be used in the light readout system in the LAr TPC of the DUNE experiment (~8400 pcs). In each of the above experiments, it is necessary to provide a large number of photodetectors with power supply.

There are two main types of power supplies: unipolar and bipolar. The advantage of a bipolar power supply is its low cost, however, they have a more complex power connection scheme for the photodetector. On the other hand, unipolar power supplies are more expensive, but have less current consumption. To provide power to SiPMs, we chose a unipolar power supply scheme. According to our technical specification, a multi-channel unipolar power supply based on the AD5535B DAC was developed with a fairly low cost ($10/channel) compared to foreign analogues. The report shows the operation scheme of the power supply, studied its characteristics and developed software for controlling and monitoring the state of the board.

Speaker: Vladislav Sharov (Laboratory of nuclear problems. V. P. Dzhelepova)

SiPM_PS_Sharov.pdf

11:15 Light detection system prototype for DUNE Near Detector TPC

The Deep Underground Neutrino Experiment (DUNE) is an international experiment for neutrino science and proton decay studies. DUNE will consist of two neutrino detector complexes placed in the world’s most intense neutrino beam. The Near-Detector complex will track particle interactions near the source of the beam, at Fermilab in Batavia, Illinois. The core component of the DUNE Near-Detector complex will be the ArgonCube Liquid Argon detector. ArgonCube proposes an advanced approach for building modular Liquid Argon Time Projection Chambers (TPCs).
To efficiently collect the scintillation light produced when particles interact within the liquid Argon TPC, a large area photon detection system is required.
JINR is developing the light detection system including front-end electronics, DAQ, and slow control which is based on the two types of a dielectric light trap with optically coupled Silicon Photomultipliers (SiPMs) for the light readout: the Light Collection Module designed and built by JINR and the ArCLight detector developed at the University of Bern. The performance of the light detection system prototype obtained in the tests of the first prototype of modular LAr TPC in Bern University will be presented.

Speaker: Mr Sergei Sokolov (JINR)

11:30 Development of methods and tools for SiPMs matrixes mass testing for the TAO detector.

TAO is one of the two liquid-scintillation detectors of the JUNO neutrino experiment (China).
TAO will be a sphere with about 2.5 meters diameter, filled with a liquid scintillator.
The TAO entire area will be covered by about 250,000 SIPMs (silicon photomultipliers).
All SiPMs need to be carefully tested.

Speaker: Alexey Chetverikov (DLNP)

Chetverikov A.V..pdf

11:45 Study of ceramic objects of the settlement of ancient Kazakhstan by methods of neutron tomography, diffraction and Ramon spectroscopy.

The territory of East Kazakhstan, including Tarbagatai and Zaisan, have been important ethnocultural centers of various tribes and peoples since ancient times. Since 2003, research has been carried out on the Shilikti monuments located in the Zaisan district of the East Kazakhstan region. During this time, four large and one medium and 20 small burial mounds were studied by excavations. East Kazakhstan, despite many years of archaeological research, is a poorly explored region of Kazakhstan. Our task in this work is to add information about the ancient pottery craft.
The special value and uniqueness of such objects requires the use of modern non-destructive testing methods for their research. To determine the mineral phase composition of the studied ceramics, the neutron diffraction method was used, and the features and spatial distribution of phases were studied by the method of neutron radiography and tomography IBR-2 (JINR, Dubna, Russia).
The obtained data on the mineral composition of the studied ceramic materials indicate the production of dishes, mainly from clay with a natural admixture of feldspars, quartz and mica. In addition, diffraction peaks associated with the presence of graphite, anatase and calcite phases were detected. Some fragments contain inclusions of organic impurities, presumably vegetation, manure or bird droppings. The data on neutron tomography made it possible to put forward an assumption about the uniformity of the heat treatment of pottery. She also showed that the outer layer of ceramic is exposed to higher temperatures, and a high attenuation coefficient indicates the presence of hydrogen-containing groups and, accordingly, a low firing temperature.

Speaker: Ayazhan Zhomartova (Joint Institute for Nuclear Research)

10:15 → 12:00 Information Technologies

https://jinr.webex.com/jinr/j.php?MTID=m90f9278cba9f80b025fd3f9fc584ce38

10:15 JINR Open Access Repository

Within the framework of the cooperation agreement between JINR and DESY, together with the participants of the JOIN2 project, an institutional repository JINR Document Server (JDS) was created at JINR for storing the information resources of the institute and providing effective access to them. JOIN² (https://join2.de) is a shared repository infrastructure that brings together eight research institutes for the development of a full-fledged scholarly publication database and repository based on the Invenio v1.1 open-source framework for large-scale digital repositories.During JDS migration to JOIN² platform, the enhancements required to handle the Cyrillic for the correct authority records display have been implemented. This enhancement is applied to other national languages also. Web forms for input the publications have been improved taking into account the types of JINR publications. The authority records of the Topical plan for JINR research and international cooperation are being downloaded to link publications to funding sources. A support of single database of JINR users entry was implemented in JDS. The pre-production version based on JOIN2 project software can be accessed publications.jinr.ru. JDS started beta-testing in March 2021.

Speaker: Tatiana Zaikina (JINR, LIT)

Zaikina_MLIT_JDS-JOIN2_AYSS2021v2.pdf

10:30 DIRAC Interware as a service for high-thoughput computing in JINR

DIRAC Interware is an open-source development platform for the integration of heterogeneous computing and storage resources. The service based on this platform was deployed and configured in Joint Institute for Nuclear Research in 2016. Now it is actively used for MPD, Baikal-GVD, and BM@N experiments. In JINR we have five big computing resources with uniform access via the DIRAC service: Tier1, Tier2, Govorun supercomputer, cloud, and NICA cluster. In particular, the DIRAC service was used as a tool for the integration of cloud resources of JINR member states. The overall performance of the united system is at least three times more efficient compared to the use of any single computing resource. Of course, using the united system adds complexity for users and requires additional effort to reach high performance. But, for the last three years of active use of the DIRAC, the approaches were elaborated to simplify the use of the system. Right now there are many tools and components developed to allow the fast construction of new workflows. The central system for high-throughput computing management also provides additional advantages in terms of resources accounting and job monitoring. Methods for performance analysis of the completed jobs were developed and used to compare different processors. The total number of completed jobs exceeds 1 million, and the total amount of computing work is around 4.5 million HS06days.
In this contribution, we will provide an overview of the system and its performance. We will describe newly developed instruments for the system behavior analysis and will present the results of their usage.

Speaker: Igor Pelevanyuk (Joint Institute for Nuclear Research)

dirac_ayss.pdf

dirac_ayss.pptx

10:45 Usage of DIRAC workload management system for distributed data processing in the BM@N experiment

BM@N (Baryonic Matter at Nuclotron) is the first experiment of the NICA project, which is aimed to study interactions between relativistic heavy ion beam and a fixed target. In the modern high-energy particle collision experiments sequential processing of obtained experimental data, as well as simulated events can be very time-consuming due to high particle multiplicity and high interaction rate. To solve the problem, BM@N data processing can be parallelized on JINR distributed computing resources: Tier-1 and Tier-2 GRID centers of the JINR Laboratory of Information Technologies (LIT), actively expanding NICA cluster and supercomputer "Govorun". DIRAC Interware platform being used in such experiments as LHCb, Belle2 has been deployed in LIT to simplify the process and combine different resources allocated for the experiment, The DIRAC system integrates the above computing resources and provides a common interface to employ them for distributed event processing. The report shows the work on using the platform for BM@N experimental and simulated data processing, its architecture, key aspects of the use and obtained results.

Speaker: Dmitry Tsvetkov (Dubna State University)

Tsvetkov-AYSS-2021.pptx

11:00 Design and implementation of the event catalogue for physics analysis in the NICA experiments

Nuclotron-based Ion Collider fAcility (NICA) experiments at the Joint Institute for Nuclear Research have already generated substantial volumes of simulated and experimental (BM@N facility) data, and it is expected that the overall number of collected events will increase from the current value of hundreds of millions to expected several billion events per year. An information system based on the event database (Event Catalogue) used in modern high-energy physics experiments is required to store and index information on events obtained at the NICA's facilities, allowing to quickly search and use only necessary physics events based on various criteria for further processing and analysis. The main goal of the information system described in the report is to improve the performance of physics analyses and data quality checks. The Event Metadata System implemented for the NICA experiments is integrated with other experiment systems and software, in particular, the ROOT-based frameworks. The access to the Event Catalogue is provided via several developed interfaces, such as the Web application, REST API, and dedicated C++ interface. The design and details of the realization of the system are presented.

Speaker: Artyom Degtyarev (MIPT)

AYSS-2021 Design and implementation of the event catalogue for physics analysis in the NICA experiments.pptx

11:15 User Web application and auxiliary services for the Condition Database of the NICA experiments

The NICA megaproject being implemented at Joint Institute for Nuclear Research (JINR) in Dubna is aimed at creating and investigating a hot baryonic matter under extreme conditions. To solve the task of storing required parameters and information on the NICA experiments, which are necessary for further processing of the obtained experimental data (as well as simulated events), the common Condition Database has been developed. For convenient management of the data stored in the database, a user web application has been implemented for viewing, changing and visualizing information on the experiments of the NICA project, such as information on sessions and runs, detectors, parameters and parameter values, and, also, generated simulation files. The report presents a user web application, its structure and important tasks, such as viewing, searching and managing the information on the NICA experiments in tabular form, visualizing summary information on stored data, are described in details. The developed auxiliary services for the Condition Database are shown, including data inspection service for checking the integrity and correct accessibility of stored experimental and simulated data. In addition, monitoring system on Grafana being used for tracking state of the Condition Database and host servers is shown.

Speaker: Mr Alexander Chebotov

AYSS_2021_Chebotov.pptx

11:30 Status of the Configuration Information System for the NICA Experiments

The Configuration Database is an essential part of a complex of information systems, which have been developed for the experiments of the NICA project at the Joint Institute for Nuclear Research. The developed database stores both a set of various configuration parameters, such as those required for setting the detectors into operation modes, for instance, a working voltage, and descriptions of a sequence of software tasks to be started and run during experiment sessions. The corresponding Configuration Information System presented in the report is based on the implemented database and provides configuration information for data acquisition and other online processing systems, activating those hardware setups, that are needed in the current experiment session. In addition, the system starts described software tasks in a required sequence and allows managing them during sessions, including transmission of messages between tasks and updating some properties. The architecture of the Configuration Information System is presented as well, which has been implemented using client-server model, where the server ensures interactions with the Configuration Database, and the client has been developed as a Web application to view and edit configuration parameters by users.

Speaker: Daria Priakhina (ЛИТ)

AYSS_Priakhina_2021_present.pdf

11:45 Parallel events reconstruction in BMNRoot framework using the PROOF system

BM@N (Baryonic Matter at Nuclotron) is the first experiment undertaken at the accelerator complex of NICA-Nuclotron. The purpose of the BM@N experiment is to study the interactions of relativistic heavy ion beams with a fixed target.

The BmnRoot framework is a software based on the FairRoot framework and developed for providing detector performance studies, event simulation, reconstruction and physics analysis of events recorded by the BM@N facility.

One of the main problems arising in BmnRoot event reconstruction is respectively long data processing time up to several seconds per collision event. If it is required to process millions of events, then the sequential processing time could reach months. In order to increase the performance, the PROOF tool was applied for the BmnRoot reconstruction macro. PROOF uses data parallelism based on the lack of the correlation for BM@N events, which could provide good scalability. The report presents the results of the work on acceleration of the event reconstruction via the PROOF package on multicore CPU.

Speaker: Aleksey Myasnikov

10:15 → 12:00 Theoretical Physics

https://jinr.webex.com/jinr/j.php?MTID=meb12aaca113321b28f8c123868a1ac0f

10:15 Massive sunset and kite diagrams with elliptics

One of the most important tasks of modern science is the search for the so-called "new physics" beyond the SM (BSM). The most promising method which is used in this quest is the search for deviations from the SM at the LHC as well as on other accelerators and experiments. At the same time, it should be noted that the vast majority of calculations in the SM are done within the framework of perturbation theory. The latter means that we need to calculate a sufficient number of terms in perturbation series. This is necessary in order to be able to distinguish the hypothetical signals of new physics from the unaccounted effects of the Standard Model. However, we cannot always accurately calculate two and higher-loop corrections. This difficulty is due to the fact that we do not have a single reliable method for the analytical calculation of the so-called elliptic Feynman integrals. The latter often appear in practical calculations. In this case, the analytical result would be most preferable to us, since it allows to obtain the most accurate predictions. In matters of analytical computations of such integrals, great success has been achieved in connection with the use of the so-called elliptic multiple polylogarithms (eMPLs). Nevertheless, we know that not all problems can be solved in terms of eMPLs. In this report, we present the results for two-loop kite diagrams with one, two, and zero massless lines. The last two cannot be expressed in terms of eMPLs, so we introduce a new class of functions that can be called iterated integrals with algebraic kernels. These results were obtained with the help of a new integral representation for sunset subgraphs and with the use of the differential equation method for the system of master integrals. We will also discuss the potential of the developed method for solving specific phenomenological problems.

Speaker: Maxim Bezuglov (JINR)

Kites_AYSS-2021.pdf

10:30 Study of nuclear contribution to breakup cross section of 11Be halo nuclei within time-dependent approach

In this work, the Coulomb breakup of one-neutron halo nuclei has been studied within the non-perturbative time-dependent approach from intermediate (70 MeV/nucleon) to low energies (5 MeV/nucleon) including the low-lying resonances in different partial and spin states of 11Be. We have shown that the inclusion of the resonant states of 11Be into the computational scheme leads to a significant improvement of the theoretical model, which gives a better agreement of the model description of the experimental data on the breakup cross sections [1, 2]. Also, the contribution of nuclear interaction to the breakup cross sections at low beam energies (5 - 30 MeV/nucleon) is studied. An optical potential between the projectile fragments and the target is easily introduced in this model.
Overall, this numerical technique allows an accurate and straightforward modelling of the nuclear interaction between the projectile and the target on a widely range of the beam energies.
The developed computational scheme opens new possibilities in investigation of Coulomb, as well as nuclear, breakup of other halo nuclei on heavy, as well as, light targets.

[1] T. Nakamura, et. al., Phys. Lett. B 331, 296 (1994).
[2] N. Fukuda, et. al., Phys. Rev. C 70, 054606 (2004).

Speaker: Dinara Valiolda (BLTP/KAZNU/INP)

10:45 Investigation of the Mo isotopes based on the collective model

The work is devoted to the study of the shapes of the Mo isotopes chain based on the collective model with the Bohr Hamiltonian. Isotopes of even nuclei Mo, namely 94Mo, 96Mo, 98Mo and 100Mo, demonstrate a change in shape from nucleus to nucleus. The low-lying spectrum of these nuclei indicates that the 94Mo nucleus has a spherical structure, 96Mo and 98Mo has a transformed transition, and 100Mo has almost deformed structure. Also recently, there has been an increased interest in the phenomenon of coexistence of forms, which can be observed in the nuclei 98Mo. Such a change in forms can be investigated in the taxonomy of low-lying levels. This phenomenon occurs when the nucleus has different shapes at different excitation energies. Using a geometric model, this paper describes the properties of collective quadrupole excitations and weak mixing of spherical and deformed configurations. In this work, the potential was selected in such a way as to describe the experimental data on the lower excitation energies and the probabilities of E2 transitions. It is shown that the low-energy spectrum of Mo isotopes can be satisfactorily described using a geometric model with a potential function that supports the coexistence of forms.

Speaker: Mariia Mardyban

11:00 Systematic study of anomalous behaviour “flat” superdeformed bands

The phenomenon of superdeformation was used many years ago to explain the fission isomers observed in the actinide nuclei. The curiosity for the superdeformation phenomena increased exponentially when a SD band in the 152Dy nucleus was observed. Many surprising properties of SD nuclei were observed experimentally, such as constant energy spacing between the transitions, lack of the transition linking the yrast SD band to the normal deformed (ND) states resulting in the 1-2 \hbar uncertainty in the spin assignments of the SD bands etc..The superdeformation spectroscopy has provided us with a great deal of information concerning the behaviour of MoI in the SD nuclei. The kinematic and dynamic moment of inertia (MoI) are two types of MoI explored in the SD nuclei. An appealing feature of the odd-A isotopes in Pb is the observation of dynamic MoI which remains nearly constant with the increasing rotational frequency (known as ``flat" SD bands). Apart from these nuclei, flat SD bands were also observed in the 192Tl where dynamic MoI does not increase with frequency. We present the empirical evidence of super rigid character of the flat superdeformed bands in the Tl and Pb isotopes. For this purpose, we have used various rotational energy formulae. The free parameters of superdeformed bands in the Tl and Pb isotopes have been extracted and systematically studied to obtain the proposed empirical evidence. In particular, the intraband transition energies of the SD bands have been split into rotational and shape fluctuation energies. The role of the vibrational factor in the evolution of dynamic moment of inertia, softness parameter, alignment and effective pairing gap parameter of the flat SD bands has been studied. Using these models, two distinct natures have been identified for the SD bands in the Tl and Pb isotopes. Our study establishes the role of shape fluctuations, vibrational effect, deformation and pairing correlations for the unusual behaviour of the dynamic moment of inertia in the flat SD bands of the 190 mass region.

Speaker: Anshul Dadwal (Dr B. R. Ambedkar National Institute of Technology, Jalandhar)

11:15 Quantum three-body problem

The quantum problem of three bodies with Coulomb interaction is one of the most notable
nonintegrable problems in quantum mechanics. At the same time, extremely accurate numerical
solutions for the problem of bound states for a system of three particles may be obtained with modern
computers. For example, the nonrelativistic energy of the ground state of helium with a nucleus of an
infinite mass is now known accurately to 46 significant digits. In the present study, a version of the
variational method (the so called ”exponential” expansion) that allows to numerically solve the
quantum Coulomb three-body bound state problem with a very high precision, which is easily
applicable as well to the states with a nonzero angular momentum, is considered. This method is used
to calculate the nonrelativistic ionization energies of a helium atom for S, P, D, and F states. It is
shown that the developed method is an efficient and flexible instrument for studying Coulomb
systems. An analysis of convergence proves that the method is highly accurate and demonstrates that
nonrelativistic energies accurate up to 28-35 significant digits may be obtained with rather moderate
efforts. Calculations of the nonrelativistic ionization energy of the negative hydrogen ion H − are also
presented.

[1] C. Schwartz, Experiment and theory in computations of the He atom ground state. Int. J. Mod.
Phys.E 15, 877 (2006); C. Schwartz, Further Computations of the He atom ground state.
ArXiv:math-phys/0605018, (2006).
[2] V.I. Korobov, Nonrelativistic ionization energy for the helium ground state. Phys.Rev. A 66,
024501 (2002).
[3] V.I. Korobov, Coulomb three-body bound-state problem: variational calculations of nonrelatistic
energies. Phys. Rev.A. 61, 064503 (2000).
[4] Baker J.D., Phys.Rev.,A41,1247 (1990).
[5] Drake , et. all. Phys.Rev.,A65,054501 (2002).
[6]Frolov A.M., Phys.Rev.,E74,027702 (2006).

Speaker: Damir Aznabayev (BLTP-KAZAKHSTAN)

11:30 Rare b→d decays in covariant confined quark model

we study the rare decays corresponding to b → d transition in the framework of the covariant confined quark model. Using the form factors, we compute the branching fractions of the rare decays and our results are found to be matching well with the experimental data. We also compute the ratios of the branching
fractions of the b → s to b → d rare decays using the inputs from previous papers on this model.

Speaker: Aidos Issadykov (Jinr)

Issadykov_AYSS2021.pdf

11:45 Global conserved quantities and unfree gauge symmetry

We consider a class of theories with unfree gauge symmetry, such that gauge parameters are restricted by differential equations. This class of theories is shown to admit global conserved quantities, whose on-shell values are defined by asymptotics of the fields rather than Cauchy data. A systematic way is proposed for deducing the global conserved quantities proceeding from the equations restricting the gauge parameters. The simplest example of such conserved quantity is the cosmological constant of unimodular gravity. We demonstrate the analogues for various higher spin field theories. The theories with unfree gauge symmetry can be self-consistently described by two different BRST complexes. One of them corresponds to the unfree gauge symmetry as such, while another one is connected with the alternative description of the same symmetry with reducible gauge transformations with unrestricted gauge parameters. These two descriptions are related, but not equivalent. For the first BRST complex, the global conserved quantities are BRST exact, and for the second one, they are BRST closed, but non-trivial.

Speaker: Ms Victoria Abakumova (Tomsk State University)

Abakumova_AYSS-2021.pdf

12:00 → 13:30 Lunch

13:30 → 15:30 Plenary session

https://jinr.webex.com/jinr/j.php?MTID=meb12aaca113321b28f8c123868a1ac0f

13:30 QCD matter in relativistic heavy-on collisions

Speaker: Prof. Grigory Nigmatkulov

14:30 Accelerator installations for proton therapy of oncological diseases

Speaker: Grigori Shirkov (JINR)

15:30 → 15:45 coffee break

15:45 → 17:15 Applied research

https://jinr.webex.com/jinr/j.php?MTID=m23f10d08e276f37848aa98c276790793

16:00 «The study of radiation defects in heterostructured semiconductors after irradiation at the irradiation facility of the IBR2 research reactor»

Heterostructures of high quality А3В5 arsenides with a quantum well based on In-Ga1-уAs exhibit high mobility of a two-dimensional electron gas and are actively used in microwave heterostructure electronics. In the heterostructures, the current-conducting layer is very thin — of the order of 10–20 nm, enclosed between wide-gap barriers; therefore, the radiation physics of such structures may differ from what was done in classical bulk semiconductors. A set of samples with heterostructures were irradiated in the irradiation unit of the IBR-2 research reactor. Preliminary results on x-ray diffraction and Raman spectroscopy are obtained.

Speaker: Almas Yskakov (Frank Laboratory of Neutron Physics)

16:15 «Currently characteristics of the irradiation facility at IBR-2 reactor for investigation of material radiation hardness»

A large number of experimental facilities are being built in the world. They will work in the fields of powerful ionizing radiation. Applied studies of the radiation resistance of materials for them is one of the most important problem. The irradiation facility of the IBR-2 reactor is designed for conducting radiation resistance studies. The length of the irradiation facility is ~8 meters. Due to this feature, the change in the densities of ionizing radiation fluxes is 105 -106 which allows for a large number of experiments. The paper will show the measured values: the differential energy density of the neutron flux, the change in the density of the fast neutron flux and the absorbed dose of gamma radiation along the irradiation facility, as well as the calculated: spectra of neutrons and gamma quanta.

Speaker: Мария Петрова

16:30 3D visualization of radiotracers for SPECT imaging using a Timepix detector with a coded aperture

The aim of the report is to demonstrate the capabilities of developed small field of view visualization system for gamma radiation sources. The measured system characteristics indicate the possibility of using it in preclinical studies on small animals. The results of tomographic studies on calibration phantoms are presented.

Speaker: Vladislav Rozhkov (JINR)

16:45 Functional characteristics of composite scintillators based on Me+ doped ZnWO4 micropowders

The developing of more technological and less expensive methods of obtaining materials with controlled functional parameters is an actual task of scintillation materials science. Significant prospects in this direction are opened in the creation of composite materials based on microcrystalline scintillation powders, which have a number of advantages in comparison with single crystals, such as more simple technology, high homogeneity of scintillation parameters thought the area and absence of linear dimensions restriction. Zinc tungstate is characterized by a large effective atomic number and high density, which allows it to be used at high energies and makes it attractive for creative of composite scintillators based on it.
It was shown [1] that the light output of the composite scintillator based on ZnWO4 micropowder obtained by solid-state synthesis with the addition of mineralizer (0.1 wt.% LiNO3) is at the level of that for the composite of grinding ZnWO4 crystal. This value exceeds the value for the ZnWO4 single crystal in 14%. However, this material is characterized by a high level of afterglow (0.361% in 3 ms after irradiation), which does not allow to offer it for use in digital radiography systems.
Therefore, the aim of this work is to develop technological approaches to obtaining luminescent microcrystalline ZnWO4 powder with improved scintillation characteristics by solid-state synthesis.
Cation doping is one of the traditional and quite common methods of controlling the scintillation characteristics of materials. The effect of cations (Li+, Rb+, Cs+), which differently incorporate into the ZnWO4 lattice and deform the emission centers, on the luminescent characteristics of the synthesized powders was investigated. The concentration of adding impurities in the reacting mixture of ZnO and WO3 was 0.3 mol.%. The maximum intensity was observed for samples doped by Rb+ and Cs+, the values of witch almost in two times exceed the value for ZnWO4 single crystal.
The concentration dependence of scintillation characteristics of synthesized powders was investigated in range 0.001 to 0.02 mol.%. Composite samples were prepared for this studies consist of ZnWO4 micropowder and a silicon rubber.
The composites based on powders synthesized with the addition of 0.01 mol.% Rb2SO4 demonstrates the light output at the level of the sample from the ground single crystal, and the afterglow level in the millisecond range is an order of magnitude lower than for the single crystal sample, which makes the obtained material promising for use in computed tomography.

1. Flexible composite scintillator based on ZnWO4 micro- and nanopowders / V.S. Tinkova, A.G. Yakubovskaya, I.A. Tupitsyna, S.I. Abashin, A.N. Puzan, S.O. Tretyak // Technologiya I konstruirovanie v elektronnoi apparature: Materials of electronics. – № 1-2. – 2019. – P. 40-49.

Speaker: Vira Tinkova

17:00 Intensive formation of K radiative centers in silicon nitride by implantation with carbon ions

The implantation of silicon nitride with carbon ions stimulates the formation of additional emitting centers, which are appearing growth points for silicon nanoclusters. Moreover, this method makes it possible to set the sizes of nanocrystals, change their concentration, as well as the properties of the "nanocluster - matrix" interface. All of the above makes photoluminescence controllable and increases its intensity[1,2].
Synthesis of silicon nitride thin film was carried out by PECVD method. The ratio of the reacting gases SiH4/N2 was 1/3 and 1/6 for the SiN1.1 and SiN1.5 samples, respectively. The carbon implantation fluencies were 1 × 10^14 cm-2, 2 × 10^15 cm-2 and 1 × 10^16 cm-2 in experiment.
The spectrum of photoluminescence was detected in the minimum fluence (1 × 10^14 cm-2) and subsequent annealing at 1100 °C for one-hour samples. It noted that at this annealing temperature an additional band appears with a maximum at 450 nm. This indicates that at a given annealing temperature, the presence of carbon leads to additional centers of radiative recombination. To confirm this effect, the duration of annealing at 1100 ° C extended to four hours. At a given duration of annealing, a luminescence signal already appears for samples implanted with increased fluencies (2 × 10^15 cm-2 and 1 × 10^16 cm-2). For sample implanted fluence of 1 × 10^14 cm-2 and annealed for four hours at 1100 °C, the luminescence spectrum is more intense and shifted to the short-wavelength region compare to sample with a similar annealing without pre-implantation. This confirms the participation of carbon atoms in the formation of radiative recombination centers at high annealing temperatures.
Acknowledgment
This research was funded the program № AP09562076 «Synthesis of Si3N4/SiO2/Si heterostructures and study of the properties of paramagnetic centers which are stable at the different annealing temperatures» by the Committee of Science of the Ministry of Education and Science of the Republic of Kazakhstan.
References
1. Mukherjee, J Bhowmik, D Mukherjee, M Satpati, B Karmakar, P Alternating silicon oxy-nitride and silicon oxide stripe formation by nitric oxide (NO+) ion implantation// Journal of applied physics.-2020.Vol.127., -P. 145302-1- 145302-10 https://doi.org/10.1063/1.5144960
2. Vlasukova, L Parkhomenko, I Komarov, F Akilbekov, A Murzalinov, D Mudryi, A Ryabikin, Y Romanov, I Giniyatova, S Luminescence of silicon nitride films implanted with nitrogen ions // Materials research express.-2018. Vol.5,№ 096414. P.1-10 http://dx.doi.org/10.1088/2053-1591/aad7a6

Speaker: Dr Danatbek Murzalinov (Institute of Physics and Technology, Satbayev University)

15:45 → 17:00 Information Technologies

https://jinr.webex.com/jinr/j.php?MTID=m90f9278cba9f80b025fd3f9fc584ce38

15:45 Approach and tools for working with Big Data on the “Govorun” supercomputer

It is noteworthy that modern HPC systems are used not only as traditional computing environments for performing massively parallel calculations, but also as systems for Big Data analysis and artificial intelligence tasks that arise in different scientific and applied problems. At the same time, despite the increase in supercomputer performance, memory and data storage bandwidths are becoming bottlenecks. To accelerate work with data for tasks of different types, solved on the “Govorun” supercomputer, a hierarchical hyperconverged data processing and storage system with a software-defined architecture was developed and implemented. This system is based on the disaggregated RSC solution for data processing and storage, which enhances the efficiency of solving user problems, as well as increases the efficiency of using both computational resources and data storage resources. It realizes a new paradigm for working with data, i.e., the integration of computing elements and novel types of data storage elements (Intel Optane PMem, Intel SSD) into a unified computing environment.
The technologies implemented on the "Govorun" supercomputer are used for efficient data processing of the MPD experiment of the NICA megaproject and in the joint projects of Meshcheryakov Laboratory of Information Technologies and Laboratory of Radiation Biology.
The studies in this direction were supported by the RFBR special grant (“Megascience – NICA”), No.18-02-40101.

Speaker: Mr Maxim Zuev

zuev_ayss2021.pdf

16:00 R-CNN plant diseases detector using triplet loss and Siamese neural networks

The main problem addressed in this work is the creation of an R-CNN plant diseases detector. We have great results with the classification task. Our current architecture based on the Siamese neural network with triplet loss function has an accuracy of more than 97%. We have a nice self-collected database with more than 1500 images – pdd.jinr.ru. Newer the less, we would like to spread the abilities of our platform with a detection function. We a limited in the training dataset so we could not use modern detectors architectures like YOLO. In the current research, we are examining the effectiveness of the R-CNN with Siamese neural networks for vegetation disease detection. One of the main reasons for the development of this detector was the fact that gardeners often send photos showing a disease that quickly spreads to neighboring leaves, for example, Gray rot, in such cases, it is necessary to accurately indicate the infected leaves for their further treatment. Infected leaves will be framed and have inscriptions corresponding to the name of the disease

Speaker: Mikhail Gerasimchuk

16:15 CERN-JINR-INP-KazNU data center: current status and plans

Modern scientific projects generate a huge amount of data that needs to be stored, processed and analyzed. It is often impossible to solve such tasks within a single scientific center. Therefore, distributed resources are combined into a single infrastructure using communication channels and specialized software. One of the important preliminary steps in building such an infrastructure is to study existing solutions and select a suitable model and algorithms for distributed data storage, processing and analysis. Building a distributed infrastructure requires software capable of solving tasks such as authentication and authorization; creation of an information system and monitoring tools; management of computing tasks, data storage and transmission. To create a CERN-JINR-INP-KazNU center for large data volumes storage, processing and analysis, a study of existing solutions was carried out and a particular model was selected

Speaker: Yelena Mazhitova (JINR)

15:45 → 17:00 Theoretical Physics

https://jinr.webex.com/jinr/j.php?MTID=meb12aaca113321b28f8c123868a1ac0f

15:45 The dipole polarizability of the doubly-magic nuclei

The study of nuclear giant resonances has long been a subject of extensive theoretical and experimental research. Experimental data on giant resonances have allowed us to determine fundamental properties associated with the nuclear interaction in the nuclear medium. In particular, the study of the giant dipole resonances (GDR) is expected to provide information on the symmetry energy term of the nuclear equation of state. This information is very relevant for the modeling of neutron stars. The energy region studied in the GDR also covers the major part relevant to a determination of the nuclear electric dipole polarizability. The electric dipole polarizability is a particularly important observable, as it can be measured in finite nuclei and it provides important information on the neutron skin thickness that can be extracted.
The new spectroscopic studies of the GDR in neutron-rich nuclei stimulate a development of the nuclear models. One of the successful tools for describing the GDR is the random phase approximation (RPA) with the self-consistent mean-field derived by making use of the Skyrme effective nucleon-nucleon interaction. As an illustration, we study the properties of the electric dipole strength distributions of 16,28 O, 40,48,60 Ca, 56,68,78 Ni, 100,132,176 Sn and 208 Pb. The nuclear dipole polarizability is computed. Our results are in reasonable agreement with available experimental data. The correlations between the nuclear dipole polarizability and the neutron skin thickness are analyzed in a systematic way.

Speaker: Nikita Solonovich

dipole polarizability of spherical nuclei.pdf

16:00 Dependences of the differential cross sections of 2D bosonic and fermionic dipoles scattering on the angles of the dipoles' mutual orientation

In recent years, two-dimensional (2D) systems of polar diatomic molecules with anisotropic interaction have attracted increased interest. Studies of the interactions of dipole diatomic molecules are also relevant due to their possible applications as qubits for quantum computing schemes.

We revealed the strong dependence of the angular distributions of the 2D dipolar scattering differential cross section $d\sigma/d\Omega$ on the angles of the dipoles' mutual orientation.
The differential cross section angular distributions for bosons exhibit circular shape in the resonant $\rho_{SR}$ points both for $\alpha=45^{\circ}$ and $\alpha=90^{\circ}$, indicating $s-$wave dominance in the resonance emergence. At dipole tilt angles, which are larger than a critical angle, the $d\sigma/d\Omega$ angular distribution has disturbed resonant-like form at the points of total cross section minimum. Whereas at the tilt angle $\alpha=90^{\circ}$ angular distributions of $d\sigma/d\Omega$ are strongly anisotropic at the points of a minimum of total cross section, indicating that the $s-$wave contribution is suppressed and the scattering is governed by higher partial waves. So, in contrast to the central potentials, the 2D low-energy dipolar scattering of bosons is strongly anisotropic and its properties are highly sensitive to the dipoles mutual orientation.
The angular distributions of differential cross section $d\sigma/d\Omega$ of the dipolar scattering of fermions are always anisotropic.The angular distributions of the 2D dipolar scattering differ significantly from the angular distributions of differential cross sections of the 3D dipolar scattering [J. L. Bohn et.al., PRA 89, 022702 (2014)]. Dipolar fermions can scatter more strongly than dipolar bosons in the 3D case [Bohn PRA 89, 022702 (2014)], whereas in a 2D case the cross section of dipolar scattering of fermions is several orders of magnitude less than the scattering cross section of bosons at low energies.
The results are published [E. A. Koval et.al. Physical Review A. 102, no. 4. 042815 (2020)].

Speaker: Eugene Koval (BLTP, JINR)

16:15 Lattice study of the phase transition in rotating gluodynamics and QCD

This report is devoted to the study of the influence of relativistic rotation on the confinement/deconfinement transition in gluodynamics within lattice simulation. To investigate the phase transition the Polyakov loop and its susceptibility are calculated for various lattice parameters and the values of angular velocities which are characteristic for heavy-ion collision experiments. Different types of boundary conditions (open, periodic, Dirichlet) are imposed in directions, orthogonal to rotation axis. Our data for the critical temperature are well described by a simple quadratic function $T_c(\Omega)/T_c(0) = 1 + C_2\Omega^2$ with $C_2>0$ for all boundary conditions and all lattice parameters used in the simulations. From this we conclude that the critical temperature of the confinement/deconfinement transition in gluodynamics increases with increasing angular velocity. This conclusion does not depend on the boundary conditions used in our study and we believe that this is universal property of gluodynamics. In addition, the preliminary lattice results for full QCD with dynamical fermions are discussed.

Speaker: Dr Artem Roenko (JINR, BLTP)

Roenko_Rotation_AYSS21.pdf

16:30 Chiral Vortical Effect for Rarita-Schwinger Fields and Chiral Anomaly

We consider the theory of Rarita-Schwinger field interacting with a field with spin 1/2, in the case of finite temperature, chemical potential and vorticity, and calculate the chiral vortical effect for spin 3/2. We have demonstrated the role of interaction with the spin 1/2 field, the contribution of the terms with which to CVE is 6. Since the contribution from the Rarita-Schwinger field is -1, the overall coefficient in CVE is 6-1=5, which corresponds to the recent prediction of a gauge chiral anomaly for spin 3/2.

Speaker: George Prokhorov (Dubna, BLTP)

16:45 Relative characteristics for estimating the neutron mass of the nuclear decay process

The purpose of the article is to theoretically evaluate the possibility of determining the value of the neutrino (antineutrino) mass in the beta decay process by measuring the relative characteristics of asymmetries and polarizations.

Research procedure and methods. The idea of ​​the method in calculating the squares of matrix elements and in minimizing the influence of poorly studied structures of nuclei and nucleons in experiments on measuring the relative characteristics.

Research results. The possibility of carrying out new laboratory experiments to determine the magnitude of the neutrino (antineutrino) mass by measuring the asymmetries and polarizations of particles is shown theoretically.

Speaker: Maksim Alibin

Thursday 14 October

10:00 → 18:00 Excursion. Ethno aul Huns

Friday 15 October

10:00 → 10:15 coffee break

10:15 → 12:00 High energy physics

https://jinr.webex.com/jinr/j.php?MTID=meb12aaca113321b28f8c123868a1ac0f

10:15 A search for the decays of stopped long-lived particles with the ATLAS detector

Long-lived particles are featured in many beyond-the-Standard Model theories. Produced in proton–proton (pp) collisions, they can come to rest within the ATLAS detector to decay some time later. The analyzed dataset is composed of pp–collisions delivered by the Large Hadron Collider at a centre-of-mass energy of √s=13 TeV and collected by the ATLAS experiment during 2017 and 2018. To detect the subsequent decays of these long-lived particles, the data used are collected during periods in the LHC bunch structure where collisions are absent. The results of this search are used to derive lower limits on the mass of gluino R-hadrons, with masses of up to 1.4 TeV excluded for gluino lifetimes of 10$^{-5}$ to 10$^{3}$ s.

Speaker: Elizaveta Cherepanova (Laboratory of Nuclear Problems)

LLP_search_Cherepanova_AYSS2021.pdf

10:30 Reconstruction in the Drift Chambers of the BM@N experiment

The Drift Chambers along with the Cathode-Strip Chambers form the outer tracker of the BM@N experiment. The full reconstruction chain for both MC and experimental data was developed and implemented into the official software.
The results of the reconstruction of Run& Bm@n data are compared to simulated data. Main performance parameters are estimated and analyzed.

Speaker: Nikolay Voytishin (JINR)

21_10_15-Voytishin_DCH_run7_MC_vs_data_ayssAlmaty.pdf

10:45 Drell-Yan angular coefficients measurements with the CMS experiment at the LHC

Updated results of measurements of angular coefficients for Z bosons produced in pp collisions and decaying to mu+mu- is presented. Results of MC simulation and data collected by the CMS detector during the LHC Run-I (2011-2012) and Run-II (2016-2018) were used.

Speaker: Vladislav Shalaev (JINR, Dubna State University)

11:00 Simulation of the NA64 experiment setup on Geant4

The Geant4 toolkit is a common instrument for the simulation of the experiments in high-energy physics. This work discusses the fixed target experiment NA64 CERN, its main goals and objectives. The model of the installation, implemented using the Geant4 package, is presented. The results of the run a simulation of a particle beam are discussed and analyzed, and physical conclusions are given.

Speaker: Elina Kasyanova

11:15 Convolutional neural networks in determining centrality by front hadron calorimeters in heavy ion reactions

The geometry of collisions in experiments with heavy ions can be determined by forward hadron calorimeters. The forward hadron calorimeters of the BM@N and MPD experiments have a design feature, namely, the presence of a hole for the beam in the center of the detector. This feature leads to the need to develop special methods for determining centrality, one of which is the use of machine learning tools. The report is devoted to the description of the application of convolutional neural networks to determine centrality.

Speaker: Nikolay Karpushkin (Institute for Nuclear Research of the Russian Academy of Sciences)

11:30 Implementation of CL’s method within GNA

CL’s one of the statistical method to explore the physics beyond the Standard Model. This method was used to set lower bounds on the Higgs boson mass. In neutrino physics, it could be used to estimate bounds of parameters of neutrino oscillations.
The base for realization CL’s method is Global Neutrino Analysis (GNA) framework, developed in JINR, Dubna. The main result of my work is a module of the GNA to make CL’s analysis with different experiments. This method will be used to estimate a region of physical value of sterile neutrino oscillations.

Speaker: Виталий Завадский (студент)

meeting.pdf

11:45 Studying electron-positron annihilation into $KK\pi$ and $KK\pi\pi^0$

Studying electron-positron annihilation into $K_SK\pi$ and $K_SK\pi\pi^0$ with the CMD-3 detector

A. A. Uskov.
Budker Institute of Nuclear Physics, Siberian Branch of the Russian Academy of Sciences.

We studied the process $e^+e^- → KK\pi$ with the СMD-3 detector at the electron-positron collider VEPP-2000. The statistics collected by the СMD-3 detector in the energy range of $1.2-2$ GeV during the 2011, 2012, 2017, 2019 runs, with a total luminosity integral of $\sim120pb^{-1}$, was used for the analysis.

The measured cross-section is crucial for the physics of light hadrons from $u, d, s$ quarks, clarifying the hadronic contribution to the anomalous magnetic moment of the muon $(g-2)_\mu$, and independently measuring the resonance parameters of both $\phi(1680)$, $\rho(1450)$. The intermediate dynamics of this process is also of interest, allowing us to check the isotopic relations and prove the dominance of the neutral $K^*(892)$ channel.

We developed a novel methodology for selecting signal events. Including multi-staged kinematic reconstruction. By adding the second stage, we reduced the background $\sim5$ more times. This stage depends on a rigorous study of the background. Since we identified - the main physical background to be the process $e^+e^- → 4\pi$.

The outline of the designed steps:

1. Kinematic reconstruction with $4$ charged tracks.
2. Track combination, to distinguish the $K_S$ meson by invariant mass and decay vertex.
3. Restriction on the energy of $\gamma$ not bound to tracks.
4. Final selection of signal events based on analysis of 2D-distribution of four-track events by energy imbalance $\Delta E$ and momentum vector sum modulus of all four particles $\Delta p$.
5. Simulation to find efficiency $\varepsilon$ and estimate systematic errors.

So, as a result of this work we not only designed a new selection algorithm, but also studied the theoretical aspect of the cross-section in the Vector Meson Dominance Framework. Therefore, we improved the world precision of $\phi(1680)$, $\rho(1450)$ and measured the cross-section of $e^+e^- → KK\pi$ with the best accuracy.

Speaker: Artem Uskov (BUDKER INSTITUTE OF NUCLEAR PHYSICS)

10:15 → 12:00 Mathematical Modeling and Computational Physics

https://jinr.webex.com/jinr/j.php?MTID=m90f9278cba9f80b025fd3f9fc584ce38

10:15 The fast and neat approach to calculate integral phase slip, implemented in CORD code, and its demonstrative run for SC230 cyclotron.

The straight forward way to calculate Integral Phase Slip (IPS) in a cyclotron is to perform beam dynamics simulation. But for IPS calculation with very high accuracy (as it will be proven bellow) the following things are enough: calculated equilibrium orbits with respect to particle energy and the voltage distribution over accelerating gaps, as well as the gaps’ position. This requires only 2D magnetic and electric field maps as an input to our multitool program – CORD, which uses Gordon’s algorithm for orbits’ calculation and special iterative procedure for IPS computation. The program and its accuracy were tested for SC230 cyclotron, but it could be applied to a vast variety of cyclotron models.

Speaker: Mr Dmitry Popov (JINR)

PopovDV AYSS-2021 upload.pptx

10:30 Optimization of the computation of the multidimensional integrals for estimation of the meson lifetime

For the analysis and prediction of experimental results in the heavy ion collision experiments the theoretical models describing the behavior of hadrons in hot and dense matter are required. Modern theoretical calculations often require the creation of a serious computer support at the level of creating new algorithms, calculation methods and software packages for solving of large systems of integro-differential equations and multidimensional integrals. In this paper we calculated the lifetime of mesons in hot and dense nuclear matter depending on the temperature, which requires calculation of the 5-dimensional integral with complicated integrand function. For this task was chosen algorithm based on Monte Carlo method of calculating integrals. The code for calculating the integral was written using the Tina’s Random Number Generator, the analysis of the dependence of the accuracy of the method on the number of selected points (convergence) was made. Due to the complexity of the integral, the number of generated events exceeded 2*$10^7$, which led to the need to parallelize computations. For optimization of computation the algorithm of parallel calculations was implemented in C++ programming language using OpenMP and NVIDIA CUDA technology. Calculations were performed on nodes with multicore CPUs and Intel Xeon Phi coprocessors and NVIDIA Tesla K40 accelerator installed within the heterogeneous cluster of the Laboratory of Information Technologies, Joint Institute for Nuclear Research, Dubna. Using the code, the lifetime of meson was calculated using all possible pion-pion scattering reactions.

Speaker: Daviti Goderidze

ConfDG_pp_AlmatyPDF.pdf

ConfDG_pp_Almaty.pptx

10:45 SFF analysis of a small angle scattering data from phospholipid vesicles systems: online interface and parallel implementation

The study of phospholipid vesicles is one of the hot topics of modern nano- and biophysics in connection with the numerous applications of these objects in medicine, pharmacology, and cosmetology. One of the most effective and intensively used methods in the last decade for studying the structure and properties of vesicles from small-angle neutron scattering (SANS) data is the separated form factor (SFF) method.
The Windows-based online interface for convenient work with a respective Fortran program is presented, which implements the fitting of the structural parameters of polydisperse vesicular systems according to experimental SANS data within the SFF model based on the standard local minimization program DFUMIL from the JINRLIB electronic library.
Due to the fact that, with a large amount of experimental data, the analysis of SANS spectra can take a significant amount of time, a parallel implementation of the adjustment of the RFF parameters based on the MPI parallel programming technology has also been developed.
The prospects of creating an information system based on the HybriLIT platform (LIT, JINR, Dubna) are discussed, which implements efficient parallel processing of small-angle spectra with a convenient web interface for entering input parameters and visualizing the results.

Speaker: Maxim Bashashin (JINR)

Bashashin MV AYSS-2021.pdf

11:00 Software development for Monte-Carlo simulation and hit-reconstruction for tracking detectors in the next runs of the BM@N experiment in 2021-2022

In this report we present the software that has been prepared for generation and processing of data sets in conformity with the features of the main tracking detectors with respect to the configuration of the BM@N setup in 2021-2022. This software has been integrated to the BmnRoot framework which was developed by the BM@N group and is used as the main software for simulation, reconstruction and analysis in the BM@N experiment.

Carrying out the experiment in the period mentioned above involves implementation of two parts of its scientific program: the first part is directed to study collisions of relativistic ion beams with fixed targets and the second part is aimed at studying the Short Range Correlation (SRC). Each part of the experiment has its own configuration of tracking detectors. In our report we will describe these configurations and what has been done concerning software development for the detectors of the central tracker comprising such detectors as FSD (Forward Silicon Detector), GEM (Gas Electron Multiplier) and CSC (Cathode Strip Chamber).

In the work particular attention is paid to preparing the detailed ROOT geometry of these detectors as the initial step of the simulation procedure based on the Monte-Carlo methods. Furthermore, the complete description of the detectors includes, in addition to the ROOT geometry, some information about parameters specific to each one of them. For this purpose in the BmnRoot framework, we make special files based on an XML format to store detector parameters for each configuration. These parametrization files are used for further digitization and hit-reconstruction procedures which are also reviewed in the report.

Speaker: Dmitry Baranov (tuta)

11:15 Investigation of dibaryons in a nuclear matter using the OpenMP implementation of the calculation of the three-particle force potential

The properties of six-quark dibaryons in a nuclear medium are investigated in relation to the description of light nuclei with A = 6. The formation of dibaryons in nuclei leads to the appearance of a three-body force between the dibaryon and the nuclear core, which makes an additional contribution to the binding energy of the three bodies, improving the agreement with the observed physical parameters. To solve the many-particle Schrödinger equation, a variational method was used in the framework of the α + 2N cluster model. The cluster wave function was represented as a superposition of multidimensional non-orthogonal Gaussian functions, which makes it possible to analytically represent the matrix elements of the Hamiltonian from single-particle operators. Since the interaction potential is nonlocal in the presence of a three-particle force, the three-particle forces were calculated numerically. The use of OpenMP technology has made it possible to significantly speed up the calculation of the matrix elements of three-particle forces, which requires significant computer time. The calculations were carried out on the heterogeneous platform HybriLIT MICC LIT JINR.

Speaker: Mr Meirzhan Kakenov (Joint Institute for Nuclear Research (JINR))

11:30 Microdosimetric Characteristics of the JINR Phasotron Therapeutic Proton Beam

The study presents and discusses the results of measurements of the contribution of particles with various LET values and their effect on the dosimetric and microdosimetric characteristics of a proton beam with the energy of 171 MeV at various depths of the beam penetration into the substance.

Proton therapy treatments are based on a proton RBE (relative biological effectiveness) relative to high-energy photons of 1.1. The use of this generic, spatially invariant RBE within tumors and normal tissues disregards the evidence that proton RBE varies with linear energy transfer (LET), physiological and biological factors, and clinical endpoint [1].

When using proton beams in radiation therapy, it is necessary to take into account the increase in the relative biological efficiency (RBE) during deceleration of the beam in biological tissue and an increase in the ionization density of protons with a decrease in the residual energy. In addition, when the proton beam passes through the substance, secondary particles with high linear energy transfer values are formed, which also increase the RBE.

The contribution of particles with high LET values to the dose of clinical proton beams was experimentally studied using a MiniPIX TPX3 camera in this experiment. MiniPIX TPX3 camera is a miniaturized and low power radiation detection camera with the state of art Timepix3 chip. The Timepix3 is the CERN's latest pixel detector chip that records position, energy and time for every detected quantum or particle of ionizing radiation [2].

In this study, based on the results of measurements of the LET spectra, the integral dosimetric and microdosimetric characteristics of the beam were determined - absorbed, equivalent and biological doses, as well as the radiation quality factor and the relative biological efficiency of the therapeutic proton beam from the JINR Phasotron.

1. H. Paganetti. Relative biological effectiveness (RBE) values for proton beam therapy. Variations as a function of biological endpoint, dose, and linear energy transfer. Phys. Med. Biol. 59 (2014) R419–R472
2. MiniPIX TPX3 Miniaturized Spectral Imaging Camera. Advacam https://advacam.com/camera/minipix-tpx3

Speaker: Ms Indira Khassenova (1.Joint Institute for Nuclear Research, Russia; 2. Institute of Nuclear Physics (INP), Kazakhstan)

12:00 → 13:30 Lunch

13:30 → 15:30 Plenary session

https://jinr.webex.com/jinr/j.php?MTID=meb12aaca113321b28f8c123868a1ac0f

13:30 Altered organization of collagen fibers in the uninvoled human colon mucosa 10 cm and 20 cm away from the colorectal cancer

Remodelling of collagen fibers has been described during every phase of cancer genesis and progression. Changes in morphology and organization of collagen fibers contribute to the formation of microenvironment that favors cancer progression and development of metastasis. However, there are only few data about remodelling of collagen fibers in healthy looking mucosa distant from the cancer. Using SHG imaging, scanning electron microscopy (SEM) and specialized softwares (CT-FIRE, CurveAlign and FiberFit), we objectively visualized and quantified changes in morphology and organization of collagen fibers. SHG polarization anysotropy was used to quantify alignment of collagen molecules inside fibers. Using immunohistochemistry (staining with anti-alphaSMA, anti-LOX, anti-MMP2 and anti-MMP9) we investigated possible causes of collagen remodelling (change in syntheses, degradation and collagen cross-linking) in the colon mucosa 10 cm and 20 cm away from the cancer in comparison with healthy mucosa. We showed that in the lamina propria this far from the colon cancer, there were changes in collagen architecture (width, straightness, alignment of collagen fibers and collagen molecules inside fibers), increased representation of myofibroblasts and increase expression of collagen-remodelling enzymes (LOX and MMP2). Thus, the changes in organization of collagen fibers, which were already described in the cancer microenvironment, also exist in the mucosa far from the cancer, but smaller in magnitude.

Speaker: Sanja Despotovic (associate professor)

Altered organization of collagen.pptx

14:30 Current status and future prospects of three flavor neutrino oscillations

Neutrino oscillations are periodic transitions between different flavor neutrinos in neutrino beams during their propagation. Modern neutrino oscillation experiments use this phenomenon to study the fundamental properties of neutrinos. Today, most of the oscillation parameters were measured at a precision level of a few percent. However, the issues of the CP violation phase value and the neutrino mass hierarchy (the order of masses of neutrinos $\nu_1$, $\nu_2$, $\nu_3$) remain open. This talk focuses on highlighting the current status and future landscape of measuring oscillation parameters in a three-flavor approximation.

Speaker: Liudmila Kolupaeva (JINR)

ayss2021_nu.pdf

15:30 → 16:00 Closing

ayss2021_closing.pdf