IBR-2 Reactor Research Articles

Study of activation cross sections of double neutron capture reaction on 193Ir for the reactor production route of radiotherapeutic 195mPt

The radiotherapeutic 195mPt is among the most effective Auger electron emitters of the currently studied radionuclides that have a potential theranostic application in nuclear medicine. Production of 195mPt through double neuron capture of enriched 193Ir followed by β−-decay to the radioisotope of interest carried out at the research reactor IBR-2 is described. Because of the high radiation background, radiochemical purification procedure of 195mPt from bulk of iridium was needed to be developed and is detailed here as well. For the first time, cross section and resonance integral for the reaction 194Ir(n,γ)195mIr were determined. Resonance neutrons contribution was established to exceed that of thermal neutrons, and resonance integral for the reaction 194Ir(n,γ)195mIr is calculated to be 2900 b. Specific activity of 195mPt was estimated to reach a value of 38.7 GBq/(g Pt) at IBR-2 by the end of bombardment (EOB).

Wide-Aperture Backscattering Detector (BSD-A) for The High-Resolution Fourier Diffractometer

The high-resolution Fourier diffractometer (HRFD) has been in routine operation since 1994 at the long-pulse neutron source, the IBR-2 reactor, in Dubna. Its fast Fourier chopper provides probably the best compromise between very high resolution in reciprocal space (Δd/d ≈ 0.001) and the intensity. For further improving intensity of TOF-diffraction pattern, a wide-aperture ring backscattering detector (BSD) has been developed on the basis of ZnS(Ag)/6LiF scintillator. BSD is designed in the form of 6 concentric rings, each of which is subdivided into 12 identical parts. The main parameters of the detector are the following: range of scattering angles is 2θ = (133 - 175) degrees, covered solid angle is Ωd ≈ 2.0 sr, average percentage absorption efficiency gets closer to 85%, geometrical contribution to resolution function does not exceed Δd/d = 0.0005. In the report the concept of the detector is described and its data acquisition system is presented. The start of operation of the detector at the HRFD is scheduled for 2024.

Using Factor Analysis To Find Source Atmospheric Pollution By Moss Technique

The aim of this investigation was to apply the moss biomonitoring technique using Barbula Indica moss and factor analysis to evaluate the possible sources of atmospheric pollution in the Thua Thien Hue province. The Barbula Indica moss samples were collected at sixteen sites in the areas of Thua Thien Hue province, the central Vietnam. The concentrations of thirty elements in the collected Barbula Indica moss samples were determined by neutron activation analyses at the reactor IBR-2 at the Joint Institute for Nuclear Research (JINR) in Dubna, Russian Federation. Factor analysis has been applied to the obtained concentrations to reveal the possible pollution sources. Rotated factor loadings suggested three factors, that could explained more than 84% of variability. Additionally, factor scores were calculated, that confirmed the presence of pollution sources in the corresponding sites.

Search for Toxic Trace Elements in Rosa rugosa Thunb. By Instrumental Neutron Activation Analysis: Accumulation and Responses to Exposure

Species of the genus Rosa L. are widely used in urban gardening, and they are of considerable interest as plants accumulating heavy metals in an urban environment. Literature data are ambiguous about whether these species accumulate trace and toxic elements. Its fruits are used as medicinal raw materials in folk and official medicine. The purpose of the study is to determine whether this type of wild rose accumulates toxic metals (as well as various macro- and microelements), if so, which ones and in which organs, and to what extent raw materials of the plant can be used. For the first time, multi-element instrumental neutron activation analysis at the reactor IBR-2 of FLNP JINR in Dubna, Russia, was applied to examine accumulation of major and trace elements in various organs of Rosa rugosa Thunb. (Rosaceae family), namely, roots, leaves, fruits and seeds. A total of 33 elements (Al, Ca, Cl, I, Mg, Mn, V, As, Br, K, La, Na, Mo, Sm, U, W, Ba, Ce, Co, Cr, Cs, Fe, Hf, Ni, Rb, Sb, Sc, Sr, Ta, Tb, Th, Yb, and Zn) were determined. Samples were taken in the summer-autumn period of 2020, both in the city of St. Petersburg and on the coast of the Baltic Sea, Russia. This research found no critical accumulation of trace and toxic elements in different organs of R. rugose, but revealed quite high accumulation of Fe and Co in urban transport highway area.

Study of 239Pu(n,f) prompt fission neutron spectrum

The experimental data concerning 239Pu prompt fission neutron spectrum above 10 MeV are sparse, and no spectrum averaged cross section has been measured in this neutron field yet. The first measurement was performed at the IBR-2 reactor, which uses plutonium dioxide fuel. The present work aimed at the measurement of spectral averaged cross sections for high threshold reactions such as 46Ti(n,p)46Sc, 54Fe(n,p)54Mn, 58Ni(n,X)57Co, 89Y(n,2n)88Y, and 209Bi(n,3n)207Bi to explore the high energy region of the 239Pu prompt fission neutron spectrum. Measurement of spectrum averaged cross section for the 89Y(n,2n)88Y reaction is included in NEA high priority request list. The 58Ni(n,p)58Co reaction was employed as a monitor reaction. The experimental spectral averaged cross sections were derived from reaction rates measured by means of high purity Germanium spectrometry. The experimental values were compared with spectrum averaged cross sections compiled from either ENDF/B-VIII.0, GMA or JEFF-3.3 239Pu prompt fission neutron spectrum and IRDFF-II cross sections. The best agreement, i.e. within uncertainties, was achieved using GMA 239Pu prompt fission neutron spectrum for all reactions under study. Calculation results using JEFF-3.3 and ENDF/B-VIII.0 evaluations of the 239Pu prompt fission neutron spectrum agree well with the experimental data except for the high energy region reflected in the disagreement with the 209Bi(n,3n)207Bi reaction.

Optimization of the cold moderator for the new pulsed reactor NEPTUN

The Frank Laboratory of Neutron Physics (FLNP) at the Joint Institute for Nuclear Research (JINR) has begun designing a new research reactor, NEPTUN, to replace the IBR-2M (pulsed fast reactor - the name in russian) reactor, which is expected to be out of service between 2032 and 2036. The IBR-2 reactor is a third-generation neutron source that started working in 1982 at Dubna, Russian Federation. The IBR-2M reactor was successfully modernized in 2012. The NEPTUN reactor is a fourth-generation neutron source that will use Np-237 as a nuclear fuel for the first time. It was studied if mesitylene (1,3,5-trimethylbenzene), which is now being utilized effectively in the reactor IBR-2M, might be used as a cold moderator in the new research reactor NEPTUN with an average thermal power of 15 MWt. A study of five materials used as a cold neutron moderator at various temperatures was also conducted. Longer working times for cold moderator material were another goal of optimization. According to the findings, mesitylene at a temperature of 20 K should be used as a cold moderator to get the greatest neutron flux at a wavelength of 3 ≤ λ ≤ 10 Å. Additionally, ortho hydrogen at 20 K could increases the cold neutron flux with wavelengths, λ ˃ 10 Å.

Erratum to: Small-Angle Neutron Scattering at the Pulsed Reactor IBR-2: Current Status and Prospects

Erratum to: Small-Angle Neutron Scattering at the Pulsed Reactor IBR-2: Current Status and Prospects

Current Characteristics of Ionizing Radiation Fields of the IBR-2 Reactor’s Irradiation Facility for Researching Materials’ Radiation Resistance

Current Characteristics of Ionizing Radiation Fields of the IBR-2 Reactor’s Irradiation Facility for Researching Materials’ Radiation Resistance

Heavy Metal Atmospheric Deposition Study in Azerbaijan Based on Moss Technique and Neutron Activation Analysis

Abstract The results of this investigation show that Azerbaijan industries and agricultural sector provide considerable anthropogenic impact on the environment of Caucasus. The use of moss biomonitoring technique and neutron activation analysis (NAA) is a first attempt to study heavy metal atmospheric deposition in Azerbaijan, a country different relief and climate. The study was undertaken in the summer of 2015 of atmospheric deposition of man-made heavy metal pollutants in the area of mining and processing plant in Gadabay and Dashkasan mininig district. At the same time samples were collected from the Goygol State Reserve in the Lesser Caucasus not far from the city of Ganja. A total 85 moss samples (predominantly Pleurozium schreberi) collected in both environmentally contrast area. Elemental determination was carried out by epithermal neutron activation analysis (ENAA) at the reactor IBR-2 of Joint Institute for Nuclear Research (FLNP JINR). For the first time 44 elemental concentrations were determined (Na, Mg, Al, Si, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Mo, Ag, Cd, In, Sb, I, Cs, Ba, La, Ce, Nd, Sm, Eu, Tb, Tm, Yb, Hf, Ta, W, Au, Th, U). Multivariate statistical analysis of the analytical results obtained will make it possible to identify the main sources of pollution and to assess the role of long-range transport of pollutants.

Assessment of the Atmospheric Deposition of Heavy Metals and Other Elements in the Mountain Crimea Using Moss Biomonitoring Technique

The atmospheric depositions of heavy metals and other elements on the territory of Crimean Mountains in 2015 was assessed using the moss biomonitoring technique. The neutron activation analysis performed at the installation REGATA of the IBR-2 reactor was used for the determination of the mass fractions of 34 elements (Na, Mg, Al, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Br, Rb, Sr, Sb, I, Cs, Ba, La, Ce, Nd, Sm, Eu, Tb, Yb, Ta, Th, and U). Factor analysis, concentration factors, and enrichment factors were used to reveal possible sources of elements in the mosses. The main contributor to the deposition of elements on the mosses was the weathering of rock materials. The second group of elements included Br and I. The agriculture and marine sources of emissions were found to be important factors of atmospheric Br and I, respectively. The representing maps of the distribution of heavy metals and other elements revealed high levels of elements at the South coast of Crimea and near the city of Simferopol. The comparison of the obtained data with the data of biomonitoring studies performed for other mountain regions showed higher levels of Al, V, Cr, Fe, Ni, and As than in the mosses from Bulgaria, Macedonia, and Norway, but lower than in the mosses from Georgia, Turkey, Romania, and Northern Serbia. The presented results could serve as a basis for future monitoring research.

Neutron Fourier Stress Diffractometer FSS at the IBR-2 Reactor: Results of Upgrading and Prospects for Further Development

Neutron Fourier Stress Diffractometer FSS at the IBR-2 Reactor: Results of Upgrading and Prospects for Further Development

Neutron Activation Analysis of PM10 for Air Quality of an Industrial Region in the Czech Republic: A Case Study

This work was conducted to focus on pollutant transmission between Poland and Czechia at the most polluted area in the Czech Republic, the Moravian Silesian region. Instrumental neutron activation analysis (INAA) and multivariate statistical analyses were used to determine the mass fractions of inorganic air pollutants accumulated on filters. Particle matters of sizes smaller than 10 µm (PM10) were collected using a high-volume sampler (SAM Hi 30 AUTO WIND). Pollutants PM10 were collected on Whatman QM-A Quartz Microfiber Filters of 150 mm in diameter based on various wind conditions. These filters were irradiated by neutron flux at the experimental reactor IBR-2 at the Joint Institute of Nuclear Research in Dubna, RF. Irradiated samples were measured by gamma spectrometry techniques using HPGe detectors. In total, results are shown for 49 samples (from March to July 2021) and five field blank filters. The mass fractions of 24 elements (Sc, Cr, Fe, Ni, Co, Zn, Se, As, Br, Rb, Mo, Sb, Ba, Cs, La, Ce, Sm, Eu, Tb, Yb, Hf, Au, Th, and U) were determined. The sources of pollution were specified using correlation and exploratory factor analyses and including meteorological conditions. A strong positive correlation was shown between the elements Cr, As, Br, Co, Fe, Sc, Se, Sm, Th, La, and Ce. Elemental exposure to PM10 can be divided based on the factor loadings of common chemical components into three main pollution sources. According to the wind rose, the pollution came from the southeast/west direction; therefore, we can assume that the pollution most likely originated from the metallurgic complex (steel and iron production in the southeast, and a coking plant, metal foundry, and generation plant in the west).

Determination of Rare Earths and Other Trace Elements in Ore Samples of Mongolia by WDXRF and INAA

Wavelength dispersive X-ray fluorescence (WDXRF) and Instrumental Neutron Activation Analyses (INAA) were used to determine the REE and other trace elements in rare earth ore samples from province Dornogovi, Lugiin gol. Seven rare-earth elements (REE) namely La, Ce, Sm, Eu, Tb, Dy, and Yb, as well as other trace elements (Zn, As, Rb, Sr, Au, Ba, Br, Ta, Hf, Th and U) have been determined by WDXRF at Central Geological Laboratory of Mongolia, Ulaanbaatar. For comparison, the same elements were determined by INAA using by epithermal neutron activation analyses at the IBR-2 reactor, FLNP JINR, Dubna. It is demonstrated that the WDXRF have satisfactorily agreed with INAA results within the limits of the uncertainty. It is shown that the values of the relative discrepancies between the WDXRF and the INAA results are in the range of 1.5-30.0 %.

The kinetics of dissolution and cluster formation of fullerene in polar and low polar solutions

Fullerene and fullerene like nanostructures play a main role in various research areas. Theamount of investigations of fullerene C60 and C70 has grown up considerably due to their several unique properties [1-2, 6]. In this report we present theoretical models for cluster growth, the modeling of small angle neutron scattering curves, and the results of structural analysis (SANS) for polar solutions of these macromolecules. Investigation of kinetics of dissolution and complex formation are studied for C60/Benzene, C60/Toluene and C60/Nmethyl-2-pyrrolidone (NMP) solutions of various concentrations by UV-Vis spectrometry. We model the kinetics of simultaneously occurring processes in the solution via a system of basic kinetic equations and obtain the corresponding parameters dependence on preparation conditions. The investigation of structural properties of fullerene solution in CS2 was performed at the YuMO instrument of the IBR-2 reactor. The results are compared tomolecular dynamics simulations, and other research works

Wide-aperture back-scattering detector (BSD) for the High-Resolution Fourier Diffractometer (HRFD) at the IBR-2 reactor

The high-resolution Fourier diffractometer (HRFD) operates at the IBR-2 pulsed reactor, on which the correlation method of data registering has been implemented using a fast Fourier chopper and specialized electronics. A wide-aperture ring back-scattering detector for HRFD has been developed. The detector consists of six Z n S ( A g ) / 6 L i F-scintillation rings, each one of which is divided into 12 sections. Main parameters of this detector: covered solid angle 2 θ = ( 133 − 175 ) ∘ ; Ω d ≈ 2.0 sr; average absorption efficiency 85 %, geometric contribution to resolution Δ d / d < 0.0005. The concept of a detector and its data acquisition system are presented.

Analysis of the rolled cotton cloth fixed on the outer surface of the International Space Station using neutron activation analysis and complementary techniques

As part of the space experiment “Test”, a roll of cotton cloth fixed on the outer surface of the International Space Station for more than 10 years was delivered to the Earth in September 2019. The elemental composition of two fragments of the cloth, contaminated and clean, was determined using instrumental neutron activation analysis at the IBR-2 reactor. Along with 19 elements (Mg, Al, Cl, Ca, Ti, Cr, Mn, Fe, Co, Ni, Zn, Rb, Sr, Ag, Sb, Ba, Sm) determined on both fragments of the cloth, additional 20 elements (Na, Si, Sc, Cu, As, Se, Br, Mo, Zr, Cd, I, La, Ce, Eu, Ta, W, Re, Ir, Th, and U) were determined only on the contaminated fragment. The morphology of the rolled cotton cloth was characterized using Scanning Electron Microscopy. Gama and liquid beta spectroscopy were applied to measure the radioactivity of the cloth fragments. Possible sources of the determined chemical elements deposited on the cloth were discussed.

Automation System for Transporting Highly Radioactive Samples of the Irradiation Facility of the IBR-2 Reactor

This paper presents the results of an automation of the processes of measuring the dose rate and movement of highly active samples in the controlled zone of the third beam of the IBR-2 reactor. A detailed analysis of the choice of an automated system based on a robotic manipulator with a video-surveillance system and distance measurement, as well as a dosimetric complex for determining the dose rate in the place of its operation, has been carried out. The processes of constructing algorithms and programs to control the robot are described in detail. It has been established that the system operates uninterruptedly and reliably in the fields of high ionizing radiation; is capable of almost completely replacing a person when performing such a work; and, most importantly, significantly—up to 27.4%—reduces the annual dose received by personnel during operation.

High-Pressure Neutron Diffraction Study of the Crystal and Magnetic Structure of Materials at the Pulsed Reactor IBR-2: Current Opportunities and Prospects

The experimental capabilities and results of recent studies of the crystal and magnetic structure of functional materials on the diffractometers DN-12 and DN-6 of upgraded high-flux pulsed reactor IBR-2 in wide ranges of high pressures and temperatures are reviewed. The combination of high neutron flux on a sample, wide-aperture multidetector systems, and focusing devices has made it possible to implement diffraction experiments on samples with record-low volumes under ultrahigh pressures (up to 35 GPa) in the temperature range of 5–300 K. The results of recent studies of the structural and magnetic phase transitions in ferroelectrics, multiferroics, low-dimensional magnets, and other materials are presented.

Small-Angle Neutron Scattering at the Pulsed Reactor IBR-2: Current Status and Prospects

Neutron diffraction studies on the small-angle neutron spectrometer YuMO (Joint Institute for Nuclear Research, Dubna), based on the IBR-2 pulsed reactor, have been reviewed. The main parameters of small-angle spectrometers, based on the time-of-flight technique, are considered. It is shown that the flux on sample is the key parameter of the spectrometers based on pulsed sources, which makes it possible (along with application of a multidetector system) to expand the dynamic range of scattering vector magnitudes. The history of the setting up of the first small-angle instrument based on pulsed sources is overviewed. The directions of development of small-angle spectrometers are shown. The results of YuMO studies in the fields of polymers, biology, materials science, and physical chemistry are briefly reviewed. The main strategies of development of small-angle neutron scattering on pulsed sources are considered. The possibilities of the small-angle instruments based on a synchrotron source and on a neutron pulsed source are compared.

Neutron Study of Internal Stress in Materials and Components

The development and current state of instrumentation for the neutron diffraction study of internal stresses has been considered. During the last 15 years, significant progress has been achieved in the experimental techniques based on stationary and pulsed neutron sources. Specialized stress diffractometers have been developed, which make it possible to solve many engineering and technological problems, as well as problems of fundamental materials science. Two Russian neutron stress diffractometers are considered: FSD on the pulsed reactor IBR-2 at the Joint Institute for Nuclear Research and STRESS on the IR-8 reactor at the Natioanl Research Centre “Kurchatov Institute.” Examples of studies performed on these devices are presented.