Russian Federal Nuclear Center Research Articles

Modern engineering solutions for an original domestic nitric oxide generator (“Tianox”)

Nitric oxide (NO) is a biologically active molecule approved for the treatment of persistent pulmonary hypertension in newborns in the USA, Japan, and most European countries in 1999 – 2008. Inhaled NO is currently used to treat a spectrum of cardiopulmonary disorders, including pulmonary hypertension in children and adults. A commercially available NO delivery system uses pressurized cylinders as a source of NO. Current cylinder-based delivery systems are widely used around the world, but they are bulky, expensive and dependent on a reliable supply chain. The aim of the work was to present an original domestic generator for NO inhalation therapy. Over the past few years, to overcome the limitations of the balloon technology, specialists from the Federal State Unitary Enterprise “Russian Federal Nuclear Center – All-Russian Research Institute of Experimental Physics” have developed a plasma-chemical NO generator that produces NO from ambient air using a nonequilibrium spark discharge plasma. In this case, a diffuse discharge mode is implemented, which ensures the most efficient synthesis of NO with the participation of excited nitrogen molecules (N2+) according to a chain mechanism similar to the Zeldovich – Semenov chain reaction. The result is a high-quality NO-containing gas mixture that does not contain toxic by-products (electrode material, ozone, etc.) usually formed in the known systems of this type. Conclusion. Based on the developed generator, the Federal State Unitary Enterprise “Russian Federal Nuclear Center – All-Russian Research Institute of Experimental Physics” designed and created the world’s first commercially available device for inhalation therapy, “Tianox”. The device was approved for circulation on the territory of the Russian Federation by order of the Federal Service for Surveillance in Healthcare (2020) based on the results of technical and clinical tests. Serial production of “Tianox” meets the requirements of ISO 13485-2016 and GOST ISO 13485-2017.

Experimental Study of the Compressibility of a Helium Plasma at a Pressure up to 20 TPa

A nonideal helium plasma has been compressed to a density of ρ ≈ 14 g/cm3 at a pressure of \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$P \\approx 20{\\kern 1pt} $$\\end{document} TPa (200 Mbar) in a spherical two-cascade device. The design of the device has been presented and the thermodynamic parameters of the helium plasma reached in it have been estimated. Data on the dynamics of the external and internal cascades in the device used to choose the calculation method have been obtained in a preliminary experiment with a hemispherical prototype. The experiment has been performed on the X-ray complex at the Russian Federal Nuclear Center All-Russian Research Institute of Experimental Physics, which includes BIM 234.3000 betatrons with a boundary energy of 60 MeV used in the multipulse bremsstrahlung generation regime with a multichannel optoelectronic system of recording X-ray images. A high-current linear accelerator LIU-R-T and an image detector assembly consisting of photochromic ADC screens have been used in addition to betatrons to detect the compressed shell cavity.

О возможности модернизации подвижных катушек электродинамических вибростендов

Currently, testing products for vibration strength and vibration resistance became much more complicated, since the mass of test objects increased, vibration modes (including vibration shocks) are of more complex nature, and, as a result, the equipment operates at the maximum modes and fails. The most complex malfunction that occurs during prolonged hard work of the vibration stand is the breakdown of a moving coil, which repair, as a rule, is possible only in the specialized centers. The paper considers design of a regular moving coil of the high-power vibration stand and indicates its disadvantages. A modernized design of the moving coil is proposed increasing its strength, as well as a device for winding it, which provides necessary tension of the conductor during winding and turning the fiberglass frame. Results of operation of the vibration units with modernized coils are presented, capabilities of the Russian Federal Nuclear Center --- Zababakhin All-Russia Research Institute of Technical Physics in terms of modernizing the vibration stands of various traction forces and structures during repair of the moving coils are indicated. Conclusion is made on the advantages of the modernized moving coils

Investigation of the Increment of Transverse Instability of a Kiloampere Electron Beam in a Linear Induction Accelerator for Its Use in a Terahertz FEL

The Institute of Nuclear Physics SB RAS in cooperation with the Russian Federal Nuclear Center VNIITF performs a series of researches aimed at acquiring a relative electron beam with energy up to 20 MeV, current up to 2 kA, and duration up to 200 ns at normalized emittance ca. 1000 π∙mm∙rad in a linear induction accelerator (LIA). In order to generate electron beams with such parameters we require thorough investigation of all main sources of perturbation of electron beam trajectory caused by different instabilities that occur during the transport and acceleration of a high currency beam in the accelerating structure of LIA. For the experimental series on measuring the dynamics of transverse oscillation of a beam, we applied a set of fast current transformers which are used for registration of beam current and mode fields caused by this beam in the structure. These measurements were performed for the electron beam with the energy of 8.5 MeV and current of 1 kA going through the structure at different modes of focusing magnetic fields size in LIA. As a result, we registered oscillation of the electromagnetic field of normal modes in the accelerating modules of LIA, as well as we determined the dependence of the oscillation amplitude of these modes’ EM field on the number of accelerating module. This dependence was compared with the result of modeling of development dynamics of transverse instability in LIA that was performed using the created program system. This allowed us to determine the size of the increment of transverse instability of a relativistic electron beam under the given experimental conditions. Based on the acquired results, we made the analysis of possibility to use the beam generated in ILA as a driver for the FEL generator of coherent impulses of THz radiation within the frequency range of 0.3–1.2 THz with a sub-gigawatt level of power.

Effects of inhaled nitric oxide in chronic obstructive pulmonary disease patients with hypercapnic respiratory failure and pulmonary hypertension

Therapy with inhaled nitric oxide (iNO) in patients with hypercapnic respiratory failure (RF) and pulmonary arterial hypertension (PAH) is currently of scientific interest. The aim of this study was to evaluate the effects of iNO therapy on COPD patients with hypercapnic RF and PAH during exacerbation of the disease.Methods. A randomized, prospective, controlled trial included 30 patients with COPD (age 65 (62; 75) years) with hypercapnic RF and pulmonary arterial hypertension (PAH) treated at the State Budgetary City Teaching Hospital “City Clinical Hospital named after D.D.Pletnev of Healthcare Moscow City Department” (2021). The inclusion criteria were: PaCO2 ≥ 45 mm Hg and pulmonary artery systolic pressure PASP > 40 mm Hg as accessed by Doppler echocardiography. The patients were divided into two groups. Patients of the main group were administered iNO in the form of daily 90-minute sessons for two weeks using Tianoks device (Russian Federal Nuclear Center – All-Russian Research Institute of Experimental Physics, State Corporation “Rosatom”, Russia). Patients of the control group received treatment that corresponded to the severity of their COPD exacerbation according to the guidelines by Global Initiative for Chronic Obstructive Lung Disease (GOLD), 2020 – 2021. Hemodynamics and gas exchange, exercise tolerance, vascular stiffness, and obstructive disorders were assessed at baseline, on Days 7 and 14.Results. The main group demonstrated a decrease in PASP (38 (32; 43) mm Hg vs 47 (44; 54) mm Hg; p = 0.001), a decrease in stiffness index (SI) (7.03 m / s (5.3; 19.2) vs 12.2 m / s (5.7; 15.1); p = 0.01), decrease the pulmonary shunt fraction (Qs / Qt) (4.33% (3.7; 6.1) vs 9.12% (7.12; 11.3); p = 0.01), an increase in arterial vascular tone measured by reflective index (RI) (62.4% (51.2; 64.3) vs 58.5% (51.7; 63.8); p = 0.01), and increased exercise tolerance measured by 6-minute walking test (6MWT) (358.1 m (320.5; 368.2) vs 321.5 m (280.4; 329.1); p = 0.001) as compared to the control group.Conclusion. Our study indicates that iNO-therapy effectively reduces hypoxemia, endothelial dysfunction, improves hemodynamics, walking distance, and exercise tolerance during the exacerbation of COPD in patients with hypercapnic RF and PAH.

Реализация функций управления задачами и ресурсами высокопроизводительной вычислительной системы в "СПО Супер-ЭВМ"

The Slurm-VNIITF software developed by Federal State Unitary Enterprise “Russian Federal Nuclear Center - Zababakhin All-Russian Research Institute of Technical Physics”, it’s architecture, resource management capabilities and task management for numerical simulation HPC systems described in this paper. During many years usage of the HPC systems researches show that the basic features of the Slurm (Simple linux utility for resource management) software are clearly insufficient for the effective use of computing resources in HPC centers. Therefore, the authors of this paper propose an improved task and resource management policy. Slurm extension modules (plugins) for implementing this policy also described in this paper.

Emittance Variation of a High-Current Relativistic Electron Beam in a Bend Magnet

The article presents the investigation results on the main angular divergence sources of a high-current relativistic electron beam when it passes through a real 12° bend magnet of the transport system in the linear induction accelerator (LIA), being developed by collaboration of Budker Institute of Nuclear Physics (BINP), Novosibirsk, Russia, and Russian Federal Nuclear Center—Zababakhin All-Russia Research Institute of Technical Physics (RFNC-VNIITF). The main results of the work are the calculated trajectories of the beam electrons, the shape of its cross section, as well as the change in the normalized emittance of the beam as it passes through the region of the bend magnet. It was shown that at typical beam parameters—electron energy of 20 MeV, beam current of 2 kA, and beam radius of 2 cm—the emittance of a high-current relativistic electron beam with uniform current and charge densities after the bend element is determined mostly by the magnet aberrations and much less by the beam self-fields. Optimization of the dipole magnet geometry made it possible to achieve a substantial decrease in the beam emittance with geometric expansion of the magnet in the median plane of the beam.

To Russia's energy security given the impact of electromagnetic pulse of the high-altitude nuclear explosion

Subject. Escalating international tensions make nuclear attacks more possible, such as a high-altitude nuclear explosion, which mainly threatens with the electromagnetic pulse. It can destroy modern electrotechnical equipment, especially if it is fitted with microprocessor equipment. Objectives. The study presents considerations on the resilience of infrastructure systems provided they are exposed to the electromagnetic pulse of a high-altitude nuclear explosion. Methods. The study is based on methods of systematization, analysis and comparison. Results. We suggest writing infrastructure system requirements into all regulatory, legislative and legal documents on the energy security and electromagnetic compatibility in case of the electromagnetic pulse of a nuclear explosion. The issue can possible be solved as professionals gather sufficient theoretical, experimental and practical data. We provide the rationale for using properly upgraded testing facilities owned by the Russian Federal Nuclear Centre of Rosatom, and making a special task-force, which could be deal with ensuring the protection of civil targets. Conclusions and Relevance. We provide the rationale for field tests of electrical facilities of infrastructure systems, including energized ones and having different load. As a result of such field test, it will be possible to determine whether the existing (and future) protective facilities and systems are efficiently used to ensure the resilience of electrotechnical equipment to the electromagnetic impulse of a high-altitude nuclear explosion, deliberate destructive effects of powerful electromagnetic generators, lightning overvoltage.

Transformation dynamics of a carbon particle on a quartz substrate in a laser field

This paper presents the results of computational–experimental studies of the laser heating of carbon (graphite) particles having a size of about 500 μm, located on a quartz substrate in inert nitrogen and argon media in the intensity range of laser radiation from 0.35 to 3.5  kW/cm2. The temperature of the particles is experimentally measured in the field where the laser radiation acts. It is shown that heating the carbon particles damages the surface of the quartz substrate in virtually the entire zone of the laser spot, with the formation of a crater whose center coincides with the center of the particle. The LOGOS software package, developed at the Russian Federal Nuclear Center—All-Russia Scientific Research Institute of Experimental Physics, is used to numerically model the process by which the laser radiation interacts with the carbon (graphite) particle lying on the quartz substrate. The results indicate that a chemical reaction occurs between the carbon and the quartz with possible formation of a layer of silicon carbide on the substrate surface.

Activities of the RFNC-VNIIEF Center of Nuclear Physics Data on the Compilation of Experimental Data for the EXFOR International Library: EXFOR-EDITOR Software Package

Experimental data on the interactions of charged particles with light nuclei have been compiled at the Institute of Nuclear and Radiation Physics of the Russian Federal Nuclear Center—All-Russian Research Institute of Experimental Physics (RFNC-VNIIEF) since 1973. Currently, this work is carried out by the staff of the Center of Nuclear Physics Data (CNPD), which was established in 1997 [1]. The paper presents the main directions of the activities of the CNPD, describes its contribution to the development of the EXFOR international library of experimental nuclear data, and gives a detailed overview of the EXFOR-Editor software package for entering, editing, and writing data on nuclear reactions in the EXFOR format [2].

Piezoelectric Method for Measuring the Parameters of Shock-Induced Ejecta

This paper describes a piezoelectric method for measuring the density and mass of ejecta from the free surface of a condensed material upon arrival of a shock wave at it and the use of this method at the Institute of Physics of Explosion (Institute of Experimental Physics of the Russian Federal Nuclear Center, Sarov). Piezoelectric sensor designs and methods of recording and signal processing are presented. Results of measuring the density and mass of ejecta using piezoelectric sensors, radiography, protonography, and the method of indicator foils are compared.

New Capabilities of Proton Radiography for Recording Fast Gas-Dynamic Processes

For about 15 years, studies of fast gas-dynamic processes have been conducted at the Logunov Institute of Experimental Physics (VNIIEF) of the Russian Federal Nuclear Center using the proton radiography system developed jointly with the Logunov Institute of High Energy Physics on the basis of a U-70 accelerator. The main advantages of flash proton radiography over widely used flash x-ray radiography are high spatial resolution, multiframe mode, transmission capability, dynamic range of recording, etc. In recent years, effort has continued to extend the capabilities of the proton radiography system by increasing the total time and recording field and supplementing it with additional diagnostic techniques and new explosion-proof chambers. This paper presents the results of studies that illustrate these capabilities.

Damage of Dusty Optical Elements in the Field of Continuous-Wave Laser Radiation

The results of experiments and numerical simulation of the effect of intense cw laser radiation on dusty optical elements damaging a sample have been reported. The numerical simulation has been performed with the LOGOS software package developed at the Russian Federal Nuclear Center VNIIEF.

Evaluation of Cross Section of 10Be Radioactive Nuclei Production at Deuteron Interaction with 9Be

The demand for more precise nuclear data on beryllium interactions is growing along with the development of controlled fusion facilities, where beryllium is already used or is planned to be used as a structural material in the coating of the first inner wall of the tokamak (the tritium breeding blanket). Evaluated cross sections of the 9Be(d, x)10Begs reaction at deuteron energies ranging from 0 to 22 MeV are presented. All available experimental data and the mathematical tools of the SaBa [1] electronic library developed at the Russian Federal Nuclear Center All-Russian Research Institute of Experimental Physics are used to obtain these cross sections.

The technique of investigation of space-time parameters of the master oscillator with fiber optical smoothing based on the slip photo recorder

The basic goal of this work is the development of investigation technique of space-time parameters of broadband oscillator of the powerful Luch Facility of the Russian Federal Nuclear Center designed to smooth radiation profile during passage of fiber optical line. The smoothing is achieved by means of modes mixing because of wave length dispersion in fiber optics, as a result the speckled radiation structure is removed. The optical scheme for recording radiation and the photochronograph with slot scan have been prepared to carry out measurements. The measurements of duration, impulse shape and space-time heterogeneity of laser radiation at output of formation system of reference radiation with fiber optical smoothing were carried out using that developed technique.

Evaluated integral cross sections of the 7Li(p, α)4He reaction

New data on the energy dependence of integral cross sections of the 7Li(p, α)4He reaction are obtained to develop the SaBa (Sarov Base) library of evaluated and experimental nuclear data at the Russian Federal Nuclear Center, All-Russia Research Institute of Experimental Physics [1]. The sum of smooth and resonance parts is used as an approximating function in the current version of the SaBa database. The smooth part is described by cubic splines. Lorentzians are used to describe resonance regions. Experimental data already available in the SaBa library are analyzed to obtain new evaluated data on the 7Li(p, α)4He reaction, and a search is conducted for new data in domestic and foreign literary sources.

ЧИСЛЕННАЯ МОДЕЛЬ МАКРОВЯЗКОГО РАЗРУШЕНИЯ СОВРЕМЕННЫХ СТАЛЕЙ МАГИСТРАЛЬНЫХ ГАЗОПРОВОДОВ

The paper discusses computer modeling of an extensive crack propagating in a gas pipeline, which (the modeling) plays an important role in determining resistivity of pipe steels to various types of failure. A modified local Gurson-Tvergaard- Niedelman (GTNm) model is presented which makes it possible to describe straight and oblique cuts, as well as a combination thereof, in viscous failure of small-size objects (bars, plates, shells). Details of the implementation of the GTNm model in the parallel FE computer program DANKO (developed in Russian Federal Nuclear Center - All-Russian Research Institute of Experimental Physics) are given. Parameters of the GTNm model have been determined based on laboratory experiments with specimens of a pipe steel of the K65 strength class. Numerical examples are given, demonstrating “working efficiency” of the GTNm model. The results are designed for numerically studying deformation, failure of specimens during tests, dynamic crack propagation in a pipeline. Keywords: steels of gas mains, small-dimension objects, viscous failure, oblique cuts, computer modeling, finite element method, modified local Gurson − Tvergaard − Niedelman (GTNm) model.

Communication Practices of Interaction of the Ural Nuclear Bomb Specialists and Government Authorities

Abstract This article focuses on communication practices of interaction between specialists in the Russian Federal Nuclear Center – All-Russian Scientific Research Institute of Technical Physics and authorities (Central Committee of the Communist Party of the Soviet Union, Ministry of Medium Machine-Building Industry of the USSR, Ministry of Defense) in 1950s –1980s. The study describes mechanisms, strategy and vectors of interaction, certain cases and content of communication with authorities as well as possibilities and limits of mutual influence of authorities and physicists on functioning of a large research production institution of the Soviet nuclear industry, on the industry itself and on state processes.

Feasibility of creating a specialized reactimeter based on the inverse solution to kinetics equation with a current-mode neutron detector

The file-evaluation results of a reactimeter based on the inverse solution to the kinetics equation (ISKE) are presented, which were obtained using an operating hardware-measuring complex with a KNK-4 neutron detector working in the current mode. The processing of power-recording files of the BR-1M, BR-K1, and VIR-2M reactors of the Russian Federal Nuclear Center—All-Russian Research Institute of Experimental Physics, which was performed with the use of Excel simulation of the ISKE formalism, demonstrated the feasibility of implementation of the reactivity monitoring (during the operation of these reactors at stationary power) beginning from the level of ~5 × 10–4βeff.

Explosion-protecting chambers for investigating hydrodynamic processes and explosive technologies (review)

Within the framework of the scientific trend that was developed at the Russian Federal Nuclear Center, All-Russian Scientific Research Institute of Experimental Physics, explosion-protecting chambers (EPCs) of different types with working volumes ranging from ∼10−3 to ∼10 m3 were developed and constructed. They are able to hermetically localize explosion products from explosive charges of units of grams to tens of kilograms (in the trinitrotoluene equivalent (TNTE)). Scientific and engineering approaches to designing the EPC structures, which are based on experimental methods and numerical simulation, are presented. Examples of developed chambers that are used in studies of a number of hydrodynamic processes are given.