Kurchatov Institute Research Articles

ТЕХНОЛОГИИ И РЕЗУЛЬТАТЫ ИССЛЕДОВАНИЙ ОБЪЕКТОВ, ПРЕДСТАВЛЯЮЩИХ ЭКОЛОГИЧЕСКУЮ УГРОЗУ, В НОВОЗЕМЕЛЬСКОЙ ВПАДИНЕ

The article is devoted to the water area research at Novaya Zemlya depression of the Kara Sea, where, according to archival data, radioactive waste was flooded. The research concerned observations of the environment state and underwater nuclear and radiation hazardous facilities, such as the nuclear fleet flooded here reactors, vessels loaded with solid radioactive waste and numerous groups of containers. The research was carried out using the technology of route sonar and video shooting based on the use of towed uninhabited underwater vehicles (BNPA) developed at IO RAS. Objects condition monitoring was provided using underwater gammaray REM spectrometers developed at the National Research Center “Kurchatov Institute”. As a result of the research, individual objects have been identified and their location archival data has been clarified. Observations of benthos and the structure of the water column in the burial area were done.

Сергей Леонидович Круглов. Физик – Человек – Учитель

The article is dedicated to the memory of Sergey Leonidovich Kruglov, leading researcher at the Department of Superconductivity and Cryogenics of the Kurchatov Institute, Doctor of Technical Sciences (habil.), Corresponding member of the Russian Academy of Electrical Sciences, Associate Professor at Moscow State Physical Institute (Nuclear University), teacher at the Kurchatov School, veteran of the nuclear industry.

Lebt of the Heavy Ion Linear Accelerator

At the NRC “Kurchatov Institute” (Kurchatov Complex for Theoretical and Experimental Physics), the pulsed linear resonant heavy ion accelerator is being developed. The Low Energy Beam Transport (LEBT) channel transports the beam from a laser-plasma source of multi-charged ions with an A/Z ratio from 4 to 8 (up to Bi27+) to the RFQ. This paper shares the results of the beam dynamics simulation of the LEBT, which ensures the separation of the working fraction of the ion beam and its matching with the RFQ.

Two cnidian plastic vessels of the 2nd century ad from the collection of the state historical museum: technological research

The article considers two textbook-famous Cnidian plastic vessels from the collection of the State Historical Museum in Moscow. One of them, shaped as a ram, comes from the excavations of N.I. Veselovsky in the Kuban region, the second one – a lagynos with erotic scenes on its body – was found by I.I. Gushchina at the Late Scythian burial ground Belbek IV in the Southwestern Crimea. As part of a project to do research on monuments of the classical period from the State Historical Museum collection, an X-ray tomographic study of these vessels was conducted at the National Research Centre “Kurchatov Institute”, which made it possible to clarify the technology of their manufacture.

Beam Dynamics in the Heavy Ion Injector LU2 for the Synchrotron Research Complex (SRC)

The project of the complex for studying ionizing radiation exposure from outer space based on the synchrotron accelerator of protons and various types of ions up to 209Bi is being developed at the Russian Federal Nuclear Center - All-Russian Research Institute ofExperimental Physics (FSUE RFNC - VNIIEF). The accelerator includes two injection complexes (one of which is the source of protons and light ions, the second - heavy ions), the booster accelerator and the main synchrotron. The pulsed type heavy ions linac is being developed at the NRC “Kurchatov Institute” - KCTEF (Kurchatov Complex for Theoretical and Experimental Physics). The ions with mass-to-charge ratio 4÷8 with current of 10 mA will be accelerated up to 4 MeV/u. The linac is proposed, including the RFQ and two DTL sections operating at multiple frequencies. Each DTL section is modular and consists of individually phased H-type resonators (IH-DTLs). Quadrupole lenses located between the resonators for the beam focusing. This DTL structure ensures the accelerator compactness and allows section-by-section configuration and sequential commissioning. 6D beam matching between all sections of the linac is carried out. The results ofbeam dynamics simulation in linear accelerator are presented.

Creating pyrolysis reactor for disposal of municipal solid waste

In order to utilize municipal solid waste (MSW), a prototype reactor for thermal processing was created using materials developed at the National Research Center “Kurchatov Institute” – Central Research Institute of Structural materials “Prometey”, the technology for decomposing MSW in the reactor was developed, and its tests were carried out. The test results allowed us to conclude that the use of pyrolysis reactors for recycling ensures the environmental safety of the process and produces high-temperature gas (1000–1200°C) suitable for further use in power plants. Technical requirements were determined for the development of an industrial reactor for the disposal of solid waste with a productivity of up to 10 t/h, taking into account the shortcomings identified during testing of the prototype.

Dynamics of the plasma ejection structure in laboratory modeling of young star jets at plasma focus facilities

The use of “plasma focus” type facilities, such as PF-3 (Kurchatov Institute), makes it possible to carry out well-controlled and diagnosable laboratory experiments to study laboratory jets with scale parameters close to the jets of young stars. In this paper, we present the results of numerical modeling of plasma outburst propagation in PF-3. A self-consistent configuration was chosen as the initial conditions, which correctly takes into account the internal structure of the jet. This allowed us to obtain a detailed structure of the interaction between the magnetized emission and the ambient gas. Due to the scalability of such a structure, one should expect such a structure from the head shock waves of jets of young stars.

Development of 10 m<sup>2</sup> hodoscope made of drift tubes for cosmic ray muon registration

The 10 m2 muon hodoscope made of drift tubes with length 3.7 m and diameter 52 mm is under development and construction in NRC “Kurchatov institute” — IHEP. Totally 768 drift tubes are grouped into 6 identical multilayers, each consisting of two tube layers with parallelly placed tubes. Tube orientation in adjacent multilayers is orthogonal, thus the hodoscope has six X and six Y tube layers. Detailed mechanical structure, on-chamber electronic and data acquisition systems are described. Expected technical characteristics and some test results are presented.

Development of a milk-containing drink fermented with chickpea extract

In recent times dairy drinks with plant extracts are in great demand, since such products, thanks to the plant component, can compensate for the deficiency of important nutrients for humans. Legumes, for example, chickpeas (Cicer arietinum L.), can be promising plant raw materials for such drinks: they are rich in biologically available protein, vitamins and dietary fiber. In addition, fermenting such drinks with lactic acid bacteria with probiotic properties can provide even greater benefits to the product. The goal of the research is to develop a technology for a milk drink containing chickpea extract, fermented with lactic acid microorganisms with probiotic properties, to increase the nutritional value and improve the organoleptic characteristics of the product. Lactic acid bacteria used in the research were previously isolated from naturally fermented products, identified and deposited in the national Bioresource Center of the All-Russian Communist Party of Moscow Scientific Research Center “Kurchatov Institute”. The strains were studied for their probiotic and technological properties, including the ability to utilize chickpea antinutritional factors. A milk-containing drink with chickpea extract was fermented with microorganisms at a temperature of 37 °C for 24 hours.The product recipe contained 45% of chickpea extract and 55% of cow milk with a fat content of 0.5%. Two compositions were composed: No. 1 – a milk-containing drink with chickpea extract, fermented with Limosilactobacillus fermentum SB-2 and Latilactobacillus sakei SD-8; No. 2 – milk drink with chickpea extract, fermented with Lactiplantibacillus plantarum PC-7 and Leuconostoc mesenteriodes CH-5. Strains were added to the product in an amount of 1×107 CFU/ml. Both drinks met microbiological requirements and had a pleasant sour-milk taste, but the first drink had light floral notes, while the second drink left a bean aftertaste. According to the research results, composition No. 1 made it possible to obtain a milk-containing drink fermented with chickpea extract, which was the most acceptable in terms of organoleptic indicators.

Production cross sections of 102mRh and 108mAg in proton bombed natPb target with 400 MeV energy

The accelerator-driven subcritical system (ADS) is a competitive option for next-generation nuclear energy systems. Production cross sections of long-lived residual radioactive nuclides in a proton-nuclide reaction are basic quantities for the calculation of accumulated radioactivity in the use of ADS systems. This work presents the production cross sections of 102mRh and 108mAg in a natural lead (natPb) target activated by 400 MeV protons. The natPb target was irradiated by a 400 MeV proton beam in NRC “Kurchatov Institute” and measured two decades later by a low background gamma spectrometer in China Jinping Underground Laboratory (CJPL). A spectrum analysis method based on simulated single-isotope spectrum and Bayesian peak fitting was employed to compute the activities and production cross sections of the residual nuclides. The experimentally measured cross-sections for 102mRh and 108mAg were 0.72 ± 0.05 mb and 0.76 ± 0.09 mb respectively. These values are approximately twice as high as those predicted by the QGSP_INCLXX_HP model and fall within the range predicted by the INCL4+ABLA and LAQGSM+GEM2 models for mass numbers A=102 and A=108. These findings offer new experimental insights for ADS research and provide a practical benchmark for theoretical models concerning proton-lead interactions.

Design and simulation of an S-band RF photogun for a linac-injector for the SYLA FEL

Currently,the 4th generation synchrotron radiation source SYLA (Synchrotron + Laser)is being developed at NRC «Kurchatov Institute». TheSYLAwillincludeof a free electron laser (FEL) and a 6 GeV storage ring with a 7BA lattice, which will allow obtaining a transverse emittance value of about 50 pm·rad. A linear accelerator for full energy is considered as both the main top-up injector into the storage ring and a driver for FEL. To generate high-brightness bunch trains for FEL, an S-band radiofrequency (RF) gun with a photocathode based on 3.5-cells π-mode standing wave accelerating structure at operating frequency of 2.8 GHz will be used. In this paper, the general concept of the RF photogun is proposed and briefly discussed. An optimization of beam dynamics is performed, electrodynamics parameters are found, fields distribution in the cavity and coaxial RF coupler are provided. Thermal analysis of the structure presented is performed.

Modelling PM dipoles with longitudinal field gradient for SILA facility

Computational models are described which were built for parametric simulations of permanent magnet (PM) dipoles with a longitudinal field gradient. The dipoles will be used as bending magnets in the synchrotron facility SILA, a new project of the National Research Center “Kurchatov Institute”. The dipoles employ a Sm-Co permanent magnet material and pure iron. The need for high magnetic performance and anticipated interference between neighbouring components is a challenge for design and construction of the magnet system. For this reason the magnet designs must rely on precision 3D simulations. The dipoles are described in detail with parameterized models. Parametric simulations are to be applied at all stages of the project till the commissioning to provide realistic prediction of the magnet behaviour.

Measurement of the Cross Section for the Neutron-Induced Fission of 237Np Nuclei in the Energy Range of 0.3–500 MeV

The cross section for the neutron-induced fission of 237Np nuclei in the neutron energy range of 0.3–500 MeV has been measured using the time-of-flight spectrometer of the GNEIS neutron complex at the Petersburg Nuclear Physics Institute, National Research Center Kurchatov Institute. The 237Np(n, f) fission cross section has been measured with respect to the 235U(n, f) fission cross section and fission fragments have been detected by low-pressure position-sensitive multiwire proportional counters. The data obtained have been compared to the previous experimental results and to estimates from various evaluated data libraries.

Atherosclerotic changes in the aortic wall in lower monkeys

Atherosclerotic changes in the walls of arterial vessels are currently considered as one of the initial stages in the development of a number of diseases of the cardiovascular system. According to the World Health Organization, atherosclerosis is the main cause of heart attack and stroke. The similarity of pathomorphological changes in atherosclerosis in humans and in lower monkeys of the baboon hamadryad and baboon anubis species allows the use of animals of these species as laboratory models in the study of this disease. The material for morphological studies was obtained during the autopsy of 109 corpses of baboon hamadryad and baboon anubis monkeys (53 males and 56 females) in the period from 2019 to 2022. To analyze the species and age characteristics, all animals were conditionally divided into three age groups: group 1 (n=74) monkeys of both sexes aged 15-20 years; group 2 (n=23) animals of both sexes aged 21-25 years; group 3 (n=12) included animals older than 26 years. The results of the research showed that atherosclerotic changes in the aortic wall in the lower monkeys of the studied species kept in the nursery of the Kurchatov Complex of Medical Primatology of the Kurchatov Institute Research Center are detected from the age of 15. As the age of the animals increases, the changes are more pronounced. A reliable relationship between different age groups has been established. The frequency of atherosclerotic changes increases with increasing age, regardless of the sex of the animals. Morphological changes in the wall of the thoracic aorta in baboons are similar to those in human atherosclerosis.

Containerized Computing with DevOps Methodology Use on the Central Linux Cluster at NRC “Kurchatov Institute”—IHEP

Containerized Computing with DevOps Methodology Use on the Central Linux Cluster at NRC “Kurchatov Institute”—IHEP

WLCG Tier-2 Computing Center at NRC “Kurchatov Institute”—IHEP: 20 Years of Operation

WLCG Tier-2 Computing Center at NRC “Kurchatov Institute”—IHEP: 20 Years of Operation

Development of the System for Recognition Sensors Indications of Engineering Equipment in the Computing Center at NRC “Kurchatov Institute—IHEP”

Development of the System for Recognition Sensors Indications of Engineering Equipment in the Computing Center at NRC “Kurchatov Institute—IHEP”

Evaluation of antihypoxic effects of therapeutic breathing mixtures with high argon content on the example of acute blood loss in laboratory animals: a preclinical randomized experimental study

Background. According to the hypothesis of the study, the therapeutic efficacy of measures to treat hypoxic (ischemic) emergencies can be significantly increased by using an artificial gas mixture with normal or increased oxygen content and a high content of argon, being bioactive despite its chemical inertness.Objective. To experimentally evaluate the antihypoxic effects of argon on the example of acute massive blood loss in experimental animals.Methods. The study was carried out on 72 albino male gray rats with a baseline body weight of 220–250 g. The experiments were performed at the premises of the Konstantinov St. Petersburg Nuclear Physics Institute of the Kurchatov Institute and the Smorodintsev Research Institute of Influenza (Russia). Prior to the experiment, the animals were quarantined for 2 weeks in the vivariums of the performing organizations. Acute massive blood loss in rats was formed by taking blood (12 ± 1% of body weight on average) using syringe method by transcutaneous cardiac puncture. Rats were randomized into 3 groups (24 individuals each) depending on the gaseous medium where the animal was placed after artificial blood loss. Composition of the applied gaseous medium in the comparison groups: medium No. 1 — oxygen 21% vol.; argon — 30% vol.; nitrogen — the rest; medium No. 2 — oxygen 21% vol.; argon — the rest; medium No. 3 (control) — air. The postoperative follow-up (post-conditioning) for 8 hours involved assessing and recording the following indicators: survival/lethality rates; recovery rates (anesthesia recovery, somatic mobilization); clinical symptoms of possible intoxication with the gas mixture during inhalation exposure. The surviving animals were then monitored for 4 days to evaluate their health and behavioral performance. Upon completing the observation period, the animals were euthanized.Results. After artificially-induced blood loss, all the non-survivors died within 1.5–8 hours after the operation. In group 1 (post-conditioning in medium No. 1), the lethality of laboratory animals amounted to 4 individuals out of 24 (16%); in group 2 (post-conditioning in medium No. 2) — 2 individuals out of 24 (8%). In the control group, the lethality rate was significantly higher — 10 animals out of 24 (42%). The surviving animals demonstrated no lethality or morbidity within 4 days after the exposure. Analysis of outcomes between experimental groups and controls revealed that the significance of differences in the lethality index between group 1 and control (by Fisher’s two-sided criterion) comprised p = 0.06; between group 2 and control — p = 0.017. When the statistical “power” of the experimental group was increased (by combining samples 1 and 2), the significance of differences in outcomes in this group compared to the control accounted for p < 0.001.Conclusion. The conducted studies confirmed the hypothesis about the pronounced antihypoxic effect of argon, which significantly increased the survival rate of experimental animals after massive artificially-induced blood loss.

Study of additive manufacturing products using neutron imaging

The article presents the results of studies of additively manufactured metal samples using neutron imaging at the IR-8 research reactor of the National Research Center “Kurchatov Institute” (NRC KI). The advantages and disadvantages of neutron imaging using monochromatic (DRAGON station) and polychromatic (PONI tomograph) neutrons when studying internal structure of the samples are demonstrated.

Diagnostic system of the facility for studying superconducting quadrupoles

For the HED@FAIR project, NRC “Kurchatov Institute” — IHEP creates four quadrupole magnets with a unique combination of a large internal diameter of the superconducting winding and a high magnetic field gradient in the magnet aperture. To evaluate these superconducting magnets in different operation modes (cooling, maintaining operating parameters, heating, and transitioning magnet to the normal state), a cryogenic facility equipped with a diagnostic system was created. The main measured parameters of the unit were temperature, pressure, and vacuum in the equipment and pipelines, levels of liquid helium and liquid nitrogen, level of the gas holder, and helium flow rate. The control devices were represented by valves with electric and valves. For processing incoming signals from sensors and generation of control actions, the equipment of the domestic company OVEN was used, particularly analog input modules MV110, discrete output modules MU110, and interface converters alternating current four and direct current power supplies. The critical part of the diagnostics system, namely, the control of cryogenic valves, was provided through analog output modules NI 9219 and input modules NI 9212 (feedback) of the CompactRIO chassis. The program part of the installation for the study of superconducting quadruples is a mnemonic diagram with interactive graphic elements, physically located on the computer (operator console), and available in the read mode via the remote desktop protocol to users outside the installation. The mnemonic scheme allows the manual control of the plant’s valves and the automatic regulation of some indicators, depending on the settings assigned by the operator. The dynamics of the processes can be monitored with graphs on the right side of the interface. These graphs are displayed on a separate display at the operator’s console, whereas they are displayed on a unified screen for remote users.