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Sample records for bystrykh nejtronakh ibr-2

  1. Selected topics in research program on the IBR-2

    International Nuclear Information System (INIS)

    Luschikov, V.I.; Pikelner, L.B.; Popov, Yu.P.; Frank, I.M.; Sharapov, E.I.; Yazvitskii, Yu.S.

    1979-01-01

    The physical parameters of the IBR-2 fast pulsed reactor and research programs carried out on the reactor are described. Design values for an instantaneous thermal neutron fluxes are: 10 17 and 10 16 cm -2 s -1 inside and from the surface of the moderator respectively. In combination with the heavy current, short pulse injector (electron induction accelerator LIU-30 being under construction now) it will become a unique neutron source for the time-of-flight investigations in the energy range from 10 -7 to 10 6 eV. The characteristics of the complex IBR-2 + LIU-30 are described. The neutron beams are numbered and their use in the condensed matter and applied research is mentioned. The program for the experiments on the IBR-2 connected with nα, nγ and nf cross section measurements as well as neutron cross section study for few nucleon systems are reported. The prospects for nuclear physics research on the LIU-30 nonmultiplying target facility are outlined using as examples the experiments with polarized neutrons and nuclei and some others. The description is illustrated with the results obtained recently on the IBR-30 operating pulsed reactor

  2. New developments of TOF neutron diffraction at the IBR-2 pulsed reactor

    International Nuclear Information System (INIS)

    Balagurov, Anatoli M.

    2001-01-01

    Development of high-resolution RTOF Fourier technique for powder neutron diffraction studies is being continued at the IBR-2 pulsed reactor in Dubna. Besides some technical improvements in the operating HRFD instrument, a new dedicated instrument, Fourier Strain Diffractometer (FSD), for investigation of residual stresses in bulk materials has been constructed at IBR-2 in 1999. With a new HRFD Fourier chopper smaller than 10 μs TOF contribution in a resolution function was obtained in the experiment with perfect Si single crystal. A series of diffraction experiments with the beams from a new methane cold neutron moderator installed at the IBR-2 in 1999 is discussed. A comparison with the results obtained with the conventional water comb-like moderator shows that for various types of experiments, which are performed at HRFD and DN-2 diffractometers, the methane cold neutron source provides better conditions. (author)

  3. Estimation of power feedback parameters of pulse reactor IBR-2M on transients

    International Nuclear Information System (INIS)

    Pepyolyshev, Yu.N.; Popov, A.K.

    2013-01-01

    Parameters of the IBR-2M reactor power feedback (PFB) on a model of the reactor dynamics by mathematical treatment of two registered transients are estimated. Frequency characteristics and the pulse transient characteristics corresponding to these PFB parameters are calculated. PFB parameters received thus can be considered as their express tentative estimation as real measurements in this case occupy no more than 30 minutes. Total PFB is negative at 1 and 2 MW. At the received estimations of PFB parameters in a self-regulation mode it is possible to consider the stability margins of the IBR-2M reactor satisfactory

  4. Recent Development of Radioanalytical Methods at the IBR-2 Pulsed Fast Reactor

    International Nuclear Information System (INIS)

    Nazarov, V.M.; Peresedov, V.F.

    1994-01-01

    Experience in the application of radioanalytical methods, including NAA, at the IBR-2 pulsed fast reactor is reviewed. Details of the instruments dedicated to neutron activation analysis and radiography studies are reported. Applications of resonance neutrons to environmental monitoring and to the investigation of high-purity materials, are examplified. 15 refs. 9 figs., 9 tabs

  5. Diffraction Experiments at the IBR-2 Pulsed Reactor with Methane Cold Neutron Source

    CERN Document Server

    Balagurov, A M; Mironova, G M; Pole, A V; Simkin, V G

    2000-01-01

    A new methane cold neutron source has been tested at the IBR-2 pulsed reactor at the Frank Laboratory of Neutron Physics. In a paper the results of experiments at neutron diffractometers HRFD and DN-2 which are placed at the IBR-2 from the methane moderator side are given. A comparison with the results obtained with the conventional water comb-like moderator is performed. The perspectives of the cold source for various kinds of neutron diffraction experiments, including atomic and magnetic structural analysis and real time experiments are discussed. It is shown, that for a huge number of the experiments which are performing at both HRFD and DN-2 the methane cold neutron source provides the better conditions than water comb-like moderator.

  6. Estimation of power feedback parameters of the IBR-2M reactor by square wave reactivity

    International Nuclear Information System (INIS)

    Pepelyshev, Yu.N.; Popov, A.K.; Sumkhuu, D.

    2016-01-01

    Parameters of the IBR-2M reactor power feedback (PFB) are estimated based on the analysis of power transients caused by deliberate square wave reactivity when the pulsed reactor operates in the self-regulation mode. The PFB of the IBR-2M is described by three linear first-order differential equations. Two components of the PFB are responsible for the negative feedback and one, for the positive. The overall feedback is negative, i.e., it has a stabilizing effect for the operation of the reactor. The slowest negative component of the PFB is probably caused by heating of the fuel. Periodically repeated in the process of exploitation, estimation of the PFB parameters is one of the methods to ensure safety operation of the reactor. [ru

  7. Statistical analysis for the pulse energy fluctuations of the IBR-2M reactor

    International Nuclear Information System (INIS)

    Morkovnikov, I.A.; Ivankov, O.I.; Kirilov, A.S.

    2012-01-01

    The work is dedicated to the automation of the registration process of measurements performed on the IBR-2 instruments. Stored information is intended for those responsible for the instruments, in order to simplify measurements accounting, provide information search and assist in the preparation of reports. The general approach to the problem is considered, which in the first phase was implemented on YuMO spectrometer using Python, PyQt, MySQL

  8. Expected performance of time-gradient magnetic field SESANS diffractometer at pulsed reactor IBR-2

    Science.gov (United States)

    Bodnarchuk, V.; Sadilov, V.; Manoshin, S.; Erhan, R. V.; Ioffe, A.

    2017-06-01

    The application of the time-gradient magnetic field neutron spin-echo technique (TGF-NSE) aiming to extend the possibilities of the REFLEX reflectometer at the pulsed reactor IBR-2 (Dubna, Russia) towards a high and medium resolution small-angle scattering is considered. This technique requires the use of a linearly increasing magnetic field in the form of the sequence of saw-teeth pulses. Such a technique is well-suited to the pulsed structure of the neutron beam at the IBR-2 reactor. The wide range of neutron wavelengths employed in the time-of-flight (TOF) operation mode allows for the simultaneous coverage of a wide range of spin-echo lengths (corresponding to a wide Q-range in conventional SANS). Virtual experiments carried out using the VITESS simulation package demonstrate that such a setup at IBR-2 will allow for the coverage of the length scales from 100 Å to 6000 Å in a single instrument setting. The use of the TGF-NSE technique in the TOF mode leads to gaps in the measured SANS curves due to the jumps of magnetic field at the end of saw-teeth pulses. However, crucially, these do not harm the quality of the data. Moreover, the lost data can be retrieved by an additional measurement with a delayed start of the magnetic pulse sequence.

  9. Correlation Fourier diffractometry: 20 Years of experience at the IBR-2 reactor

    Science.gov (United States)

    Balagurov, A. M.; Bobrikov, I. A.; Bokuchava, G. D.; Zhuravlev, V. V.; Simkin, V. G.

    2015-05-01

    The high-resolution Fourier diffractometer (HRFD) was commissioned at the IBR-2 pulsed reactor at FLNP JINR in 1994. The specific feature of the HRFD design is the use of fast Fourier chopper for modulating the primary neutron beam intensity and the correlation method of diffraction data acquisition. This allowed to reach with HRFD extremely high resolution (Δ d/ d ≈ 0.001) over a wide range of inter-planar spacings at a relatively short flight path between chopper and sample ( L = 20 m). Over time, a lot of diffraction experiments on crystalline materials, the main goal of which was to study their atomic and magnetic structures, were performed at HRFD. Successful implementation of the Fourier diffractometry technique at the IBR-2 reactor stimulated the construction of yet another Fourier diffractometer intended for internal mechanical stress studies in bulk materials (FSD, Fourier Stress Diffractometer). In this paper the experience of using this technique at the IBR-2, which is a long-pulse neutron source, is considered, the examples of HRFD studies are given, and possible solutions for existing technical problems of using correlation diffractometry and ways of increasing the intensity and resolution of HRFD are discussed.

  10. Application of cluster analysis and autoregressive neural networks for the noise diagnostics of the IBR-2M reactor

    Science.gov (United States)

    Pepelyshev, Yu. N.; Tsogtsaikhan, Ts.; Ososkov, G. A.

    2016-09-01

    The pattern recognition methodologies and artificial neural networks were used widely for the IBR-2M pulsed reactor noise diagnostics. The cluster analysis allows a detailed study of the structure and fast reactivity effects of IBR-2M and nonlinear autoregressive neural network (NAR) with local feedback connection allows predicting slow reactivity effects. In this work we present results of a study on pulse energy noise dynamics and prediction of liquid sodium flow rate through the core of the IBR-2M reactor using cluster analysis and an artificial neural network.

  11. Status and perspective of development of cold moderators at the IBR-2 reactor

    International Nuclear Information System (INIS)

    Kulikov, S; Shabalin, E

    2012-01-01

    The modernized IBR-2M reactor will start its operation with three water grooved moderators in 2011. Afterwards, they will be exchanged by a new complex of moderators. The complex consists of three so-called kombi-moderators, each of them containing a pre-moderator, a cold moderator, grooved ambient water moderators and post-moderators. They are mounted onto three moveable trolleys that serve to deliver and install moderators near the reactor core. The project is divided in three stages. In 2012 the first stage of development of complex of moderators will be finished. The water grooved moderator will be replaced with the new kombi-moderator for beams nos. 7, 8, 10, 11. Main parameters of moderators for this direction will be studied then. The next stages will be done for beams nos. 2-3 and for beams nos. 1, 9, 4-6, consequently. Cold moderator chambers at the modernized IBR-2 reactor are filled with thousands of beads (∼3.5 - 4 mm in diameter) of moderating material. The cold helium gas flow delivers beads from the charging device to the moderator during the fulfillment process and cools down them during the reactor cycle. The mixture of aromatic hydrocarbons (mesithylen and m-xylen) has been chosen as moderating material. The explanation of the choice of material for novel cold neutron moderators, configuration of moderator complex for the modernized IBR-2 reactor and the main results of optimization of moderator complex for the third stage of moderator development are discussed in the article.

  12. Status and perspective of development of cold moderators at the IBR-2 reactor

    Science.gov (United States)

    Kulikov, S.; Shabalin, E.

    2012-03-01

    The modernized IBR-2M reactor will start its operation with three water grooved moderators in 2011. Afterwards, they will be exchanged by a new complex of moderators. The complex consists of three so-called kombi-moderators, each of them containing a pre-moderator, a cold moderator, grooved ambient water moderators and post-moderators. They are mounted onto three moveable trolleys that serve to deliver and install moderators near the reactor core. The project is divided in three stages. In 2012 the first stage of development of complex of moderators will be finished. The water grooved moderator will be replaced with the new kombi-moderator for beams #7, 8, 10, 11. Main parameters of moderators for this direction will be studied then. The next stages will be done for beams #2-3 and for beams #1, 9, 4-6, consequently. Cold moderator chambers at the modernized IBR-2 reactor are filled with thousands of beads (~3.5 - 4 mm in diameter) of moderating material. The cold helium gas flow delivers beads from the charging device to the moderator during the fulfillment process and cools down them during the reactor cycle. The mixture of aromatic hydrocarbons (mesithylen and m-xylen) has been chosen as moderating material. The explanation of the choice of material for novel cold neutron moderators, configuration of moderator complex for the modernized IBR-2 reactor and the main results of optimization of moderator complex for the third stage of moderator development are discussed in the article.

  13. Recent development of radioanalytical method at IBR-2 pulsed fast reactor of the JINR

    International Nuclear Information System (INIS)

    Nazarov, V.M.; Pavlov, S.S.; Herrera, E.

    1991-01-01

    The experience of the use of radioanalytical methods, including NAA at IBR-2 pilsed fast reactor of the JINR, is discussed. Physical and technical parameters of the experimental installation designed for NAA and radiography are given. The detailed examples of the application of resonance neutrons to the control of the environment in the geology of oil, in multi-element analysis of food products and superpure materials as well as in nuclear physics are reviewed. The works on the application of the neutron isotopes sources for express determination of nitrogen content in original and synthetic materials are introduced. 7 refs.; 8 figs.; 3 tabs

  14. Liquid Argon Pollution Tests of the ATLAS Detector Materials at IBR-2 Reactor in Dubna

    CERN Document Server

    Leroy, C; Cheplakov, A P; Chumakov, V; Golikov, V; Golovanov, L B; Golubyh, S M; Kukhtin, V; Kulagin, E; Luschikov, V; Minashkin, V F; Shalyugin, A N; Tsvinev, A P

    1999-01-01

    A cold test facility has been in operation since October 1998 at the IBR-2 reactor of JINR, Dubna. During four measurement campaigns, various samples of the ATLAS forward (FCAL) and hadronic end cap (HEC) calorimeter materials have been exposed to a fast neutron ($E_n \\geq 100$ keV) fluence of about 10$^{16}$~n~cm$^{-2}$. The samples were immersed in a liquid argon cryostat, and an $\\alpha$-cell has been used as purity monitor. Results of the liquid argon pollution study obtained during these measurement campaigns are presented.

  15. A concept for the modernization of a SANS instrument at the IBR-2M pulsed reactor

    International Nuclear Information System (INIS)

    Erhan, R.V.; Manoshin, S.; Pepy, G.; Kuklin, A.I.; Belushkin, A.V.; Zamfir, N.V.

    2011-01-01

    We consider a new configuration for a neutron small angle scattering instrument at the pulsed IBR-2M reactor with a mixed (cold and thermal) moderator system. This system provides added-up spectra from the cold and thermal parts of the moderator. We have installed the spectrometer using a special collimation system formed by two parts: primary with neutron optics element (divergent neutron guide) and secondary (installed after the divergent neutron guide) with a multiple pinhole collimation system. Our efforts have the goal to obtain smaller Q min values (as well as higher resolution) with the possibilities to take advantage of an increased neutron flux compared with the present SANS spectrometer in the limited beam hall size. The Monte Carlo simulations will be used to choose and optimize the spectrometer and extraction system using VITESS software package.

  16. Neutron diffraction potentialities at the IBR-2 pulsed reactor for nondestructive testing of structural materials

    International Nuclear Information System (INIS)

    Balagurov, A.M.; Bokuchava, G.D.; Papushkin, I.V.; Sumin, V.V.; Venter, A.M.

    2010-01-01

    Neutron diffraction is widely used for investigations of residual and applied stresses in bulk materials and components. The most important factor in these investigations is the high penetration depth of neutrons (up to 2 cm for steel). At the IBR-2 pulsed reactor in Dubna the Fourier stress diffractometer (FSD) has been constructed to optimize the internal stress measurements. The FSD design satisfies the requirements of high luminosity, high resolution and specific sample environment. The collimator system guarantees a minimum gauge volume of 2x2x2 mm. A mechanical testing machine allows in-situ tension or compression measurements up to a load of 20 kN and sample temperatures up to 800 deg C. In the paper the current status of FSD is reported and potentialities are demonstrated with several examples of investigations performed

  17. Liquid argon pollution tests of ATLAS detector materials at the IBR-2 reactor in Dubna

    CERN Document Server

    Leroy, C; Golubyh, S M; Kukhtin, V; Merkulovm L; Minashkin, V F; Golikov, V V; Kulagin, E N; Luschikov, V; Golovanov, L B; Borzunov, Yu T; Chumakov, V; Tsvinev, A P; Shalyugin, A N

    2002-01-01

    aA cold irradiation test facility operated at the IBR-2 reactor of JINR, Dubna, is used to investigate the behaviour under neutron and gamma irradiations of samples of materials and equipments to be used in the ATLAS forward (FCAL) and the hadronic end cap (HEC) liquid argon calorimeters. The samples under study are immersed in a liquid argon cryostat and exposed to fast neutron (E/sub n/ >or= 100 keV) fluences of about 10/sup 16/ n cm/sup -2/ equivalent to the neutron fluence accumulated in FCAL during ten years of LHC operation. An alpha -cell is used to check for possible outgassing due to irradiation of the samples immersed in liquid argon and to monitor the liquid argon purity. The results of various irradiation tests performed at this facility are reported. (6 refs).

  18. Project of the new multifunctional reflectometer GRAINS with horizontal sample plane at the IBR-2M pulsed reactor in Dubna

    International Nuclear Information System (INIS)

    Avdeev, M V; Bodnarchuk, V I; Lauter-Pasyuk, V V; Lauter, H; Aksenov, V L; Yaradaikin, S P; Ulyanov, V A; Trounov, V A; Kalinin, S I

    2010-01-01

    The new multifunctional reflectometer GRAINS is under construction at the modernized high flux IBR-2 pulsed reactor (IBR-2M) of the FLNP JINR (Dubna, Russia). The principal feature of this reflectometer, the horizontal sample plane (or vertical scattering plane), enables the study of liquid-containing interfaces. The reflectometer will operate in the time-of-flight regime with constant sample illumination during measurements. The important advantage is the constant angular resolution with unvaried background. The additional modes of the GRAINS reflectometer comprise (1) off-specular scattering and GISANS, which are measured simultaneously in the TOF regime at a 2D position-sensitive detector; (2) angular encoding in the horizontal plane, which is provided by a Larmor precession region limited by current sheets in front of the sample; (3) 3D polarimetry in reflection, which is provided by a Larmor precession region around the sample position. The design of the reflectometer is optimised to take better advantage of an exceptionally broad wavelength band of the new cold moderator at the IBR-2M. The set-up will open up principally new possibilities for investigations in the field of interface nano-science at the IBR-2M reactor.

  19. Large-scale Samples Irradiation Facility at the IBR-2 Reactor in Dubna

    CERN Document Server

    Cheplakov, A P; Golubyh, S M; Kaskanov, G Ya; Kulagin, E N; Kukhtin, V V; Luschikov, V I; Shabalin, E P; León-Florián, E; Leroy, C

    1998-01-01

    The irradiation facility at the beam line no.3 of the IBR-2 reactor of the Frank Laboratory for Neutron Physics is described. The facility is aimed at irradiation studies of various objects with area up to 800 cm$^2$ both at cryogenic and ambient temperatures. The energy spectra of neutrons are reconstructed by the method of threshold detector activation. The neutron fluence and $\\gamma$ dose rates are measured by means of alanine and thermoluminescent dosimeters. The boron carbide and lead filters or $(n/\\gamma)$ converter provide beams of different ratio of doses induced by neutrons and photons. For the lead filter, the flux of fast neutrons with energy more than 0.1 MeV is $1.4 \\cdot 10^{10}$ \\fln and the neutron dose is about 96\\% of the total radiation dose. For the $(n/\\gamma)$ converter, the $\\gamma$ dose rate is $\\sim$500 Gy h$^{-1}$ which is about 85\\% of the total dose. The radiation hardness tests of GaAs electronics and materials for the ATLAS detector to be put into operation at the Large Hadron ...

  20. First experience with the new solid methane moderator at the IBR-2 reactor

    International Nuclear Information System (INIS)

    Beliakov, A.A.; Shabalin, E.P.; Tretyakov, I.T.

    2001-01-01

    In the 1999 Fall the solid methane moderator (CM) has been installed and tested at full power at the IBR-2 pulsed reactor. Its main features are a beryllium reflector and a light water premoderator. Radiation load on the methane was three times as much as that of IPNS facility, namely, 0.1 W/g. Effects of temperature, operation time, concentration of a hydrogen scavenger, and annealing procedure on both neutron and service performances were studied. Maximum operation time of a newly loaded portion of methane was 4 days. In this time around 30% of methane is transformed into hydrogen, ethane, and high molecular hydrocarbons, and yet no deterioration in cold neutron intensity was detected. Among new knowledge, the most important are two facts observed: two-fold decrease in hydrogen formation rate when methane is poisoned with 2.5% to 5% of ethylene, and low formation rate of solid, inremovable products of radiolysis - (1.5/3)10 -7 g/J, which means that after 10 years of operation the methane chamber will be filled with only 100 g of residue. Gain of factor 20 in cold neutron flux was obtained as compared to the routine grooved light water moderator. Presently, it is the highest among the intense pulsed neutron sources. (author)

  1. Investigation of the dynamics of pulse energy noise at the IBR-2M reactor in the fuel burnup

    International Nuclear Information System (INIS)

    Pepelyshev, Yu.N.; Tsogtsaikhan, Ts.

    2017-01-01

    In this paper, we present the results of a study on the pulse energy noise dynamics of the IBR-2M in the fuel burnup for a significant period of the reactor operation, starting from the date of its commissioning in 2011 and until the end of 2016. It is shown that the pulse energy noise during the operation of the IBR-2M with burnup to about ∼1100 MW·day changes significantly by both the spectral component and the level. The standard deviation of the random power fluctuations did not exceed 5% and was less than allowable. In addition, the low level of low-frequency noise (∼1,6%) indicates the absence of sign of vibrational instability of the reactor and a substantial margin of burnup until instability. [ru

  2. Measurement of cold neutron spectra at a model of cryogenic moderator of the IBR-2M reactor

    International Nuclear Information System (INIS)

    Kulikov, S.A.; Chernikov, A.N.; Shabalin, E.P.; Kalinin, I.V.; Morozov, V.M.; Novikov, A.G.; Puchkov, A.V.

    2010-01-01

    The article is dedicated to methods and results of experimental determination of cold neutron spectra from solid mesitylene at neutron moderator temperatures 10-50 K. Experiments were fulfilled at the DIN-2PI spectrometer of the IBR-2 reactor. The main goals of this work were to examine a system of constants for Monte Carlo calculation of cryogenic moderators of the IBR-2M reactor and to determine the temperature dependence of cold neutron intensity from the moderator. A reasonable agreement of experimental and calculation results for mesitylene at 20 K has been obtained. The cold neutron intensity at temperature of moderator 10 K is about 1.8 times higher than at T=50 K

  3. Perspectives and possibilities for solid state physcis investigations at thhe pulsed reactor IBR-2 of the JINR Dubna

    International Nuclear Information System (INIS)

    Feldmann, K.; Frauenheim, T.; Lauckner, J.; Weniger, J.; Muehle, E.

    1982-02-01

    Three time-of-flight spectrometers (spectrometer of high resolution NSWR, spectrometer of inverted geometry KDSOG and spectrometer of polarized neutrons SPN-1) are presented, which will be working at the pulsed IBR-2 reactor of the JINR Dubna. Considering the parameters and the special methods of measurement of these spectrometers, the possibilities of their applications for the investigations of structural, magnetic and electronic properties of solids by means of elastic, inelastic and quasielastic neutron scattering are discussed. (author)

  4. An experiment on the investigation of the possibilities of the detection of heated UCN at the IBR-2

    International Nuclear Information System (INIS)

    Kalchev, S.D.; Strelkov, A.V.

    1990-01-01

    An experiment on the investigation of the heating of ultracold neutrons (UCN) in the reactor IBR-2 is described. By measuring the flux of thermal neutrons (upscattered UCN heated on polyethylene) the UCN flux density in a neutron guide is estimated to be approx. 25 cm -2 s -1 . The paper reports on the analysis of the background of a counter of heated neutrons. 9 refs.; 5 figs

  5. The New Water Moderator of the IBR-2 Reactor with a Canyon on the Lateral Surface. Design and Physical Parameters

    CERN Document Server

    Korneev, D A; Bodnarchuk, V I; Peresedov, V F; Rogov, A D; Shabalin, E P; Yaradaikin, S P

    2003-01-01

    An element of the new cold methane moderator of the reactor IBR-2, the water premoderator, serves as a thermal moderator for the 9th and 1st channels. Neutron radiation in the direction of the 9th channel comes from the lateral surface of the moderator. A specific feature of the reflectometer REFLEX located on the 9th channel is that it only "sees" neutrons emitted from a limited region of the moderator surface. This region is a rectangular extended along a vertical with a horizontal dimension of about 7 mm. To increase the flux on the sample, a groove-like pocket (canyon) with a depth of 80 mm by the width 15 mm and height 200 mm was cut in the premoderator on its lateral surface. The design of the moderator and the results of measurements of the neutron flux distribution on the lateral surface of the moderator are presented.

  6. Automation system for neutron activation analysis at the reactor IBR-2, Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia.

    Science.gov (United States)

    Pavlov, Sergey S; Dmitriev, Andrey Yu; Frontasyeva, Marina V

    The present status of development of software packages and equipment designed for automation of NAA at the reactor IBR-2 of FLNP, JINR, Dubna, RF, is described. The NAA database, construction of sample changers and software for automation of spectra measurement and calculation of concentrations are presented. Automation of QC procedures is integrated in the software developed. Details of the design are shown.

  7. Study of the Possibility of Reducing the Slow Fluctuations of the Reactivity and Thermal Power of the IBR-2M Reactor

    Science.gov (United States)

    Pepelyshev, Yuri; Tsogtsaikhan, Tsolmon

    2018-02-01

    This paper presents an artificial neural network method for long-term prediction of the thermal dynamic parameters of the IBR-2M reactor. Attention is focused mainly on the prediction of the temperature and sodium flow at the entry into the core as well as the thermal power. It is shown that the prediction makes it possible to reduce by a factor of 3 the influence of slow fluctuations of reactivity on the power and thereby reduce the operational requirements for the automatic power stabilization system.

  8. Control system of executive mechanisms of a spectrometer on the IBR-2 reactor as a modern local network of controllers CAN

    International Nuclear Information System (INIS)

    Zhuravlev, V.V.; Kirillov, A.S.; Petukhova, T.B.; Sirotin, A.P.

    2007-01-01

    Controllers SMC-32 and SMC-32-CAN as elements of control systems of executive mechanisms of the IBR-2 spectrometers are submitted. The controllers provide management of executive mechanisms of spectrometers on the consecutive communication line RS232, RS422 (SMC-32, SMC-32-CAN), and on the local network CAN (SMC-32-CAN). The control systems of the executive mechanisms are easily modernized due to connection of additional elements of the local network CAN. Dynamic characteristics of the spectrometers' executive mechanisms are essentially improved. For example, it has been possible to increase the rotation frequency of the step motor DSHI-200 up to 10000 pps. (author)

  9. CsPb0.9Sn0.1IBr2Based All-Inorganic Perovskite Solar Cells with Exceptional Efficiency and Stability.

    Science.gov (United States)

    Liang, Jia; Zhao, Peiyang; Wang, Caixing; Wang, Yanrong; Hu, Yi; Zhu, Guoyin; Ma, Lianbo; Liu, Jie; Jin, Zhong

    2017-10-11

    The emergence of perovskite solar cells (PSCs) has generated enormous interest in the photovoltaic research community. Recently, cesium metal halides (CsMX 3 , M = Pb or Sn; X = I, Br, Cl or mixed halides) as a class of inorganic perovskites showed great promise for PSCs and other optoelectronic devices. However, CsMX 3 -based PSCs usually exhibit lower power conversion efficiencies (PCEs) than organic-inorganic hybrid PSCs, due to the unfavorable band gaps. Herein, a novel mixed-Pb/Sn mixed-halide inorganic perovskite, CsPb 0.9 Sn 0.1 IBr 2 , with a suitable band gap of 1.79 eV and an appropriate level of valence band maximum, was prepared in ambient atmosphere without a glovebox. After thoroughly eliminating labile organic components and noble metals, the all-inorganic PSCs based on CsPb 0.9 Sn 0.1 IBr 2 and carbon counter electrodes exhibit a high open-circuit voltage of 1.26 V and a remarkable PCE up to 11.33%, which is record-breaking among the existing CsMX 3 -based PSCs. Moreover, the all-inorganic PSCs show good long-term stability and improved endurance against heat and moisture. This study indicates a feasible way to design inorganic halide perovskites through energy-band engineering for the construction of high-performance all-inorganic PSCs.

  10. Automation system for measurement of gamma-ray spectra of induced activity for multi-element high-volume neutron activation analysis at the IBR-2 reactor of FLNP at JINR

    International Nuclear Information System (INIS)

    Pavlov, S.S.; Dmitriev, A.Yu.; Chepurchenko, I.A.; Frontas'eva, M.V.

    2014-01-01

    The automation system for measurement of induced activity of gamma-ray spectra for multi-element high-volume neutron activation analysis (NAA) was designed, developed and implemented at the IBR-2 reactor. The system consists of three devices of automatic sample changers for three Canberra HPGe detector-based gamma spectrometry systems. Each sample changer consists of two-axis linear positioning module M202A by DriveSet (DriveSet.de) company and disk with 45 slots for containers with samples. Control of automatic sample changer is performed by the Xemo S360U controller by Systec (systec.de) company. Positioning accuracy can reach 0.1 mm. Special software performs automatic changing of samples and measurement of gamma spectra at constant interaction with the NAA database. The system is unique and can be recommended for other laboratories as one of the possible ways of the NAA integrated automation

  11. Qualitative and quantitative analysis of arsenic and mercury in human remains of the XVI-XVII centuries from the Moscow Kremlin necropolises by neutron activation analysis at the IREN facility and the IBR-2 reactor of FLNP, JINR

    International Nuclear Information System (INIS)

    Panova, T.D.; Dmitriev, A.Yu.; Borzakov, S.B.; Khramko, K.

    2017-01-01

    The neutron activation analysis (NAA) of three samples of human remains of the XVI-XVII centuries from the necropolises of the Moscow Kremlin has been carried out at FLNP JINR. The samples were irradiated at two facilities: at the IREN source of resonance neutrons and at the IBR-2 reactor. Spectra of induced activity of the irradiated samples were measured by using the automatic measurement system developed at FLNP JINR. This system consists of a high-purity germanium detector with spectrometric electronics, a sample changer, and a control software. Mass fractions of arsenic, mercury and other elements were calculated by relative and absolute NAA methods. The obtained values confirmed the fact of an acute mercury poisoning of the first wife of Tsar Ivan Vasilievich the Terrible - Tsarina Anastasia Romanovna. Increased mercury content was detected in the bone remains of the son of Tsar Ivan the Terrible, Tsarevich Ivan Ivanovich, and Prince M. V. Skopin-Shuisky. The obtained results allow us to introduce into scientific circulation the exact values of mass fraction of mercury, arsenic and some other elements in the samples from the graves of Russian historical figures of the second half of XVI - early XVII centuries. [ru

  12. Analysis of arsenic and mercury content in human remains of the 16th and 17th centuries from Moscow Kremlin necropolises by neutron activation analysis at the IREN facility and the IBR-2 reactor FLNP JINR

    Science.gov (United States)

    Panova, T. D.; Dmitriev, A. Yu.; Borzakov, S. B.; Hramco, C.

    2018-01-01

    A neutron activation analysis (NAA) of three samples of human remains of the 16th and 17th centuries from the necropolises of the Moscow Kremlin has been carried out at FLNP JINR. The samples were irradiated at two facilities: the IREN source of resonance neutrons and the IBR-2 reactor. Spectra of the induced activity of the irradiated samples were measured by using the automatic measurement system developed at the Frank Laboratory of Neutron Physics (FLNP) of the Joint Institute for Nuclear Research (JINR). This system consists of a high-purity germanium detector with spectrometric electronics, a sample changer, and control software. Mass fraction of arsenic, mercury, and some other elements were calculated using two NAA methods—relative and absolute. The obtained values confirm the fact of acute mercury poisoning of Anastasia Romanovna, the first wife of Tsar Ivan Vasil'evich the Terrible, the first Russian Tsarina (died in 1560). High levels of mercury were detected in the bone remains of Tsarevich Ivan Ivanovich (died in 1581), the son of Tsar Ivan the Terrible, and Prince Mikhail Vasil'evich Skopin-Shuiskii (died in 1610). The results provide an opportunity to introduce into scientific circulation the exact values of mass fraction of mercury, arsenic, and other elements in the samples taken from the burials of the Russian historical figures of the second half of 16th-early 17th century.

  13. Solid methane cold moderator for the IBR-2 reactor

    International Nuclear Information System (INIS)

    Beliakov, A. A.; Tretiakov, I. T.; Shabalin, E. P.; Golikov, V. V.; Luschivkov, V I.

    1997-09-01

    The paper describes the research and design work carried out since 1986 at the Frank Laboratory of Neutron Physics of the Joint Institute for Nuclear Research in Dubna to create a cryogenic moderator for the IBR-22 reactor using solid methane as a moderating substance.

  14. Arrangement of remote control of spectrometers on IBR-2M reactor

    International Nuclear Information System (INIS)

    Kirilov, A.S.; Murashkevich, S.M.; Okulov, R.Yu.; Petukhova, T.B.; )

    2009-01-01

    The principles of arranging and design features of the WebSonix system consisting of the central web-site and interface equipment with spectrometers are considered. The system allows one to reflect the actual statuses of all spectrometer components, view the measurements protocols, display the accumulative spectra, and control the course of the experiment on the spectrometers under control of the Sonix+ software package (Windows XP operational system). The system does not depend on the spectrometer characteristics and permits simple changes of their structure and easy adaptation to special features of spectrometric data representation. The system is based on PHP and Python scripts. The GNU/Linux Debian operational system and Apache 2 web server are installed on the web-site computer [ru

  15. The Polarized Neutron Spectrometer REMUR at the Pulsed Reactor IBR-2

    CERN Document Server

    Aksenov, V L; Kozhevnikov, S V; Lauter, H; Lauter-Pasyuk, V; Nikitenko, Yu V; Petrenko, A V

    2004-01-01

    A new polarized neutron spectrometer REMUR has been constructed and commissioned. The spectrometer REMUR is dedicated to investigations of multilayers and surfaces by polarized neutron reflection and of the inhomogeneous state of solids by diffuse small-angle polarized neutron scattering. The spectrometer operates in the neutron wavelength interval 1\\div 10 A. In the reflectometry mode it allows one to complete polarization analysis and neutron position-sensitive detection within the solid angle of scattering 2.2\\cdot 10^{-4} rad. The spectrometer ensures good statistics of the reflectometric data in the scattering wave vector interval 3\\cdot 10^{-3}\\div 5\\cdot 10^{-1} A^{-1}. In the small-angle scattering mode the spectrometer allows the investigation of neutron scattering processes without spin-flip over the detector's neutron registration solid angle interval from 4\\cdot 1-^{-3} to 10^{-1} rad and the scattering wave vector interval from 0.006\\div 0.15 to 0.03\\div 0.7 A^{-1}, respectively.

  16. The polarized neutron spectrometer REMUR at the pulsed reactor IBR-2

    International Nuclear Information System (INIS)

    Aksenov, V.L.; Zhernenkov, K.N.; Kozhevnikov, S.V.; Nikitenko, Yu.V.; Petrenko, A.V.; Lauter, H.J.; Lauter-Pasyuk, V.

    2004-01-01

    At the Laboratory of Neutron Physics (JINR, Dubna) the new polarized neutron spectrometer REMUR has been constructed and commissioned. The spectrometer REMUR is dedicated to investigations of multilayers and surfaces by polarized neutron reflection and of the inhomogeneous state of solids by diffuse small-angle polarized neutron scattering. The spectrometer operates in the neutron wavelength interval 1-10 Angstroem. In the reflectometry mode it allows one to complete polarization analysis and neutron position-sensitive detection within the solid angle of scattering 2.2·10 -4 rad. The spectrometer ensures good statistics of the reflectometric data in the scattering wave vector interval 3·10 -3 - 5·10 -1 Angstroem -1 . In the small-angle scattering mode the spectrometer allows the investigation of neutron scattering processes without spin-flip over the detector's neutron registration solid angle interval from 4·10 -3 to 10 -1 rad and the scattering wave vector interval from 0.006-0.15 to 0.03-0.7 Angstroem -1 , respectively

  17. SANS contrast variation method applied in experiments on ferrofluids at MURN instrument of IBR-2 reactor

    Science.gov (United States)

    Balasoiu, Maria; Kuklin, Alexander

    2012-03-01

    Separate determination of the nuclear and magnetic contributions to the scattering intensity by means of a contrast variation method applied in a small angle neutron scattering experiment of nonpolarized neutrons in ferrofluids in early 90 's at the MURN instrument is reviewed. The nuclear scattering contribution gives the features of the colloidal particle dimensions, surfactant shell structure and the solvent degree penetration to the macromolecular layer. The magnetic scattering part is compatible to the models where is supposed that the particle surface has a nonmagnetic layer. Details on experimental "Grabcev method" in obtaining separate nuclear and magnetic contributions to the small angle neutron scattering intensity of unpolarized neutrons are emphasized for the case of a high quality ultrastabile benzene-based ferrofluid with magnetite nanoparticles.

  18. SANS contrast variation method applied in experiments on ferrofluids at MURN instrument of IBR-2 reactor

    International Nuclear Information System (INIS)

    Balasoiu, Maria; Kuklin, Alexander

    2012-01-01

    Separate determination of the nuclear and magnetic contributions to the scattering intensity by means of a contrast variation method applied in a small angle neutron scattering experiment of nonpolarized neutrons in ferrofluids in early 90 's at the MURN instrument is reviewed. The nuclear scattering contribution gives the features of the colloidal particle dimensions, surfactant shell structure and the solvent degree penetration to the macromolecular layer. The magnetic scattering part is compatible to the models where is supposed that the particle surface has a nonmagnetic layer. Details on experimental 'Grabcev method' in obtaining separate nuclear and magnetic contributions to the small angle neutron scattering intensity of unpolarized neutrons are emphasized for the case of a high quality ultrastabile benzene-based ferrofluid with magnetite nanoparticles.

  19. Investigation of internal mechanical stresses in materials and products using high-resolution Fourier-diffractometer at IBR-2 reactor

    International Nuclear Information System (INIS)

    Aksenov, V.L.; Balagurov, A.M.; Bokuchava, G.D.; Simkin, V.G.; Taran, Yu.V.; Shamsutdinov, N.R.; ); Bulkin, A.P.; Kudryashov, V.A.; Trunov, V.A.; Shrajber, Yu.

    1997-01-01

    A high resolution Fourier diffractometer was applied to study elastic properties of austenitic steel Kh6CrNiTi1810 under external uniaxial load and residual internal stresses, resulted from material fatigue, to determine residual stresses in two-layer tubes manufactured by weld-surfacing austenitic stainless steel with a ferritic one as well as to measure residual stresses in Al 2 O 3 /Al cermets. The data on stress distribution in the specimens investigated are presented. It is concluded about a good agreement between results of diffraction studies and mechanical tests [ru

  20. A fan analyzer of neutron beam polarization on the spectrometer REMUR at the pulsed reactor IBR-2

    International Nuclear Information System (INIS)

    Ul'yanov, V.A.; Pusenkov, V.M.; Pleshanov, N.K.

    2004-01-01

    The new spectrometer of polarized neutrons REMUR has been created and put in operation at the Frank Laboratory of Neutron Physics (JINR, Dubna). The spectrometer is dedicated to investigations of multilayer structures and surfaces by registering the reflection of polarized neutrons and of the inhomogeneous state of solid matter by measuring the small-angle scattering of polarized neutrons. The spectrometer's working range of neutron wavelengths is 1.5-10 Angstroem. The spectrometer is equipped with a linear position-sensitive detector and a focused supermirror polarization analyzer (the fan-like polarization analyzer) with a solid angle of polarized neutron detection of 2.2·10 -4 rad. This paper describes the design and the principle of operation of the fan analyzer of neutron polarization together with the results of the fan tests on a polarized neutron beam

  1. On the use of a composite moderator at the IBR-2 reactor: Advantages for the neutron-diffraction texture analysis of rocks

    Czech Academy of Sciences Publication Activity Database

    Bulavin, M. V.; Vasin, R.N.; Kulikov, S.A.; Lokajíček, Tomáš; Levin, D.M.

    2016-01-01

    Roč. 10, č. 4 (2016), s. 677-686 ISSN 1027-4510 Institutional support: RVO:67985831 Keywords : cold moderator * neutron-diffraction texture analysis * phase analysis * Rietveld method Subject RIV: DB - Geology ; Mineralogy

  2. Modern tendencies in development of small-angle neutron scattering in studying the structure of biological macromolecules

    International Nuclear Information System (INIS)

    Serdyuk, I.N.

    1997-01-01

    The paper presents a brief discussion of the tendencies in development of the theory and practical application of small-angle neutron scattering for studying the structure of biological macromolecules. Special attention is focused on the studies carried out in the Laboratory of Neutron Physics at the unique Ibr-2 pulse reactor in Dubna

  3. Automation of reactor neutron activation analysis

    International Nuclear Information System (INIS)

    Pavlov, S.S.; Dmitriev, A.Yu.; Frontasyeva, M.V.

    2013-01-01

    The present status of the development of a software package designed for automation of NAA at the IBR-2 reactor of FLNP, JINR, Dubna, is reported. Following decisions adopted at the CRP Meeting in Delft, August 27-31, 2012, the missing tool - a sample changer - will be installed for NAA in compliance with the peculiar features of the radioanalytical laboratory REGATA at the IBR-2 reactor. The details of the design are presented. The software for operation with the sample changer consists of two parts. The first part is a user interface and the second one is a program to control the sample changer. The second part will be developed after installing the tool.

  4. Particles and nuclei, letters

    International Nuclear Information System (INIS)

    2000-01-01

    The present collection of letters from JINR, Dubna, contains eight separate records on liquid argon pollution tests of the ATLAS detector materials at IBR-2 reactor in Dubna, irradiation tests of readout chain components of the ATLAS liquid argon calorimeters, study of neutron induced outgassing from tungsten alloy for ATLAS FCAL, yields of nuclear reaction products from a thick beryllium target bombarded by beams of 7 Li, 11 B and 15 N ions as well as on the mass surface and the properties of nuclides close to hypothetic doubly magic lead-164, the Web-site of information-diagnostic system of IBR-2 pulsed neutron source state, discovery of η-mesic nuclei and calculation of the ion angular distributions after the ionization in ion-atom collisions

  5. A 15-year forward look at neutron facilities in JINR

    International Nuclear Information System (INIS)

    Aksenov, V.L.

    2017-01-01

    The service life of the IBR-2 reactor, one of the leading pulse neutron sources in the world, is expected to end in 2032. Modern trends in sciences where neutrons are used, possible variants of a concept for a new neutron source and its potential position in the world neutron landscape are discussed. The flagship experiments for a new neutron source in the fields of condensed matter research, fundamental and nuclear physics are proposed. [ru

  6. Irradiation tests of readout chain components of the ATLAS liquid argon calorimeters

    International Nuclear Information System (INIS)

    Leroy, C.; Cheplakov, A.; Golikov, V.; Golubykh, S.; Kukhtin, V.; Kulagin, E.; Lushchikov, V.; Minashkin, V.; Shalyugin, A.

    2000-01-01

    Various readout chain components of the ATLAS liquid argon calorimeters have been exposed to high neutron fluences and γ doses at the irradiation test facility of the IBR-2 reactor of JINR, Dubna. Results of the capacitance and impedance measurements of coaxial cables are presented. Results of peeling tests of PC board samples (carton and copper strips) as a measure of the bonding agent irradiation hardness are also reported

  7. Reconciling Through Science Exhibition Science Bringing Nations Together

    CERN Multimedia

    2000-01-01

    Over 200 experiments are carried out now with the pulsed neutron reactor IBR-2. They involve physicists, biologists and chemists from the scientific centres of the JINR Member States and other countries. Major contributions are made by the physicists from Germany, Hungary, Poland, and Russia. During a visit to Dubna, Niels Bohr took an interest in a simple idea behind the periodic pulsed reactor and said: "I admire the courage of the people who ventured to build such a remarkable facility!"

  8. European Science Notes Information Bulletin Reports on Current European/ Middle Eastern Science

    Science.gov (United States)

    1988-07-01

    also be heptacarcinogenic, mutagenic and biodegradation of effluents and solid wastes. teratogenic . G. Llewellyn and coworkers (Virginia The...Less than a week old, the thallium compound TTF)2X, where X = 13, IBr2, or Cu(NCS)2, have very results were confirmed by several respected laboratories...to 108 K, and the J.M. Tarascon of Bellcore, Red Bank, New Jersey, (highly toxic) thallium -based compounds with Tc’s of 118 related success in using

  9. JINR-DUBNA an International center of Nuclear Research

    Science.gov (United States)

    Gudima, K.; Baznat, M.

    2015-04-01

    A short History of the Joint Institute of the Nuclear Research in Dubna (Russian Federation) has been given. The Facilities : The Synchrophasotron, the Nuclotron-M, the IBR-2 Reactor,The Heavy Ions Isochronous cyclotrons U-400 and U-400M, Phasotron, The impuls resonance neutronic device IREN has been described. A short history of collaboration between JINR and scientists from Moldova has been given. The main new tendencies in Science management has been outlined.

  10. Neutron Fourier Diffractometer FSD for Internal Stress Analysis First Results

    CERN Document Server

    Aksenov, V L; Bokuchava, G D; Zhuravlev, V V; Kuzmin, E S; Bulkin, A P; Kudryashov, V A; Trounov, V A

    2001-01-01

    At the IBR-2 pulsed reactor (FLNP, JINR) a specialised instrument - neutron Fourier diffractometer FSD - intended for internal stress measurements in bulk materials is under construction. Internal stress studies by neutron diffraction has been successfully developed last years in leading neutron centres, including Dubna and Gatchina, due to several important advantages of this method in comparison with other techniques. In current work the operation principles and construction of the diffractometer, basic parameters and outcomes of test experiments are presented.

  11. The Model of Temperature Dynamics of Pulsed Fuel Assembly

    CERN Document Server

    Bondarchenko, E A; Popov, A K

    2002-01-01

    Heat exchange process differential equations are considered for a subcritical fuel assembly with an injector. The equations are obtained by means of the use of the Hermit polynomial. The model is created for modelling of temperature transitional processes. The parameters and dynamics are estimated for hypothetical fuel assembly consisting of real mountings: the powerful proton accelerator and the reactor IBR-2 core at its subcritica l state.

  12. A study of formation of iron nanoparticles in aluminium matrix with helium pores

    Czech Academy of Sciences Publication Activity Database

    Kichanov, S.E.; Kozlenko, D. P.; Belushkin, A.V.; Reutov, V.F.; Samoilenko, S.O.; Jirák, Zdeněk; Savenko, B. N.; Bulavin, L. A.; Zubavichus, Y.V.

    2012-01-01

    Roč. 351, č. 1 (2012), "012013-1"-"012013-5" ISSN 1742-6588. [International Workshop on SANS-YuMO User Meeting at the Start-up of Scientific Experiments on the IBR-2M Reactor - Devoted to the 75th anniversary of Yu M Ostanevich's Birth /2./. Dubna, 27.05.2011-30.05.2011] Institutional research plan: CEZ:AV0Z10100521 Keywords : iron nanoparticles * aluminium matrix * helium pores Subject RIV: BM - Solid Matter Physics ; Magnetism

  13. Small-angle neutron scattering investigations of Co-doped iron oxide nanoparticles. Preliminary results

    Science.gov (United States)

    Creanga, Dorina; Balasoiu, Maria; Soloviov, Dmitro; Balasoiu-Gaina, Alexandra-Maria; Puscasu, Emil; Lupu, Nicoleta; Stan, Cristina

    2018-03-01

    Preliminary small-angle neutron scattering investigations on aqueous suspensions of several cobalt doped ferrites (CoxFe3-xO4, x=0; 0.5; 1) nanoparticles prepared by chemical co-precipitation method, are reported. The measurements were accomplished at the YuMO instrument in function at the IBR-2 reactor. Results of intermediary data treatment are presented and discussed.

  14. Time-resolved neutron diffraction investigation of effect of hydrogen on the high-Tc superconductor YBa2Cu3O7-δ

    International Nuclear Information System (INIS)

    Balagurov, A.M.; Mironova, G.M.; Rudnickij, L.A.; Galkin, V.Yu.

    1991-01-01

    We have undertaken a time-resolved neutron diffraction study of the process of effect of hydrogen on the YBa 2 Cu 3 O 7-δ in a wide region of d hkl . This method was developed at the pulsed reactor IBR-2 on the time-of-flight diffractometer DN-2 and recently reported. Such technique makes it possible to investigate the solid state chemical reactions in situ with a temporal resolution of several seconds. (orig./BUD)

  15. More recent swine vesicular disease virus isolates retain binding to coxsackie-adenovirus receptor, but have lost the ability to bind human decay-accelerating factor (CD55).

    Science.gov (United States)

    Jimenez-Clavero, Miguel A; Escribano-Romero, Estela; Ley, Victoria; Spiller, O Brad

    2005-05-01

    Swine vesicular disease virus (SVDV) evolved from coxsackie B virus serotype 5 (CVB5) in the recent past, crossing the species barrier from humans to pigs. Here, SVDV isolates from early and recent outbreaks have been compared for their capacity to utilize the progenitor virus receptors coxsackie-adenovirus receptor (CAR) and decay-accelerating factor (DAF; CD55). Virus titre of CVB5 and SVDV isolates It'66 and UK'72 on human HeLa cells was reduced by pre-incubation with either anti-DAF or anti-CAR antibodies; however, recent SVDV isolates R1072, R1120 and SPA'93 did not infect HeLa cells lytically. CVB5 and SVDV infection of the pig cell line IB-RS-2 was inhibited completely by anti-CAR antibodies for all isolates, and no reduction was observed following pre-incubation of cells with anti-pig DAF antibodies. Expression of human DAF in the pig cell line IB-RS-2 enhanced the virus titre of early SVDV isolates by 25-fold, but had no effect on recent SVDV isolate titre. Binding of radiolabelled CVB5 to IB-RS-2 cells was increased seven- to eightfold by expression of human DAF and binding of early SVDV isolates was increased 1.2-1.3-fold, whereas no increase in binding by recent SVDV isolates was mediated by human DAF expression. Addition of soluble hDAF-Fc inhibited CVB5, but not SVDV, infection of pig cells. Pre-incubation of all viruses with soluble hCAR-Fc blocked infection of IB-RS-2 pig cells completely; titration of the amount of soluble hCAR-Fc required to block infection revealed that early isolate UK'72 was the least susceptible to inhibition, and the most recent isolate, SPA'93, was the most susceptible.

  16. Russia: Overview of activities on Neutron Imaging (NI) and Cultural Heritage (CH) studies

    International Nuclear Information System (INIS)

    Kozlenko, Denis

    2012-01-01

    The development of neutron imaging techniques as a tool for non-destructive analysis of the internal structure, defects and processes in industrial products, functional materials, objects of cultural heritage attracts considerable attention at the present time. The dedicated instruments are available at the many neutron sources. The IBR-2M high flux pulsed reactor is one of the most powerful pulsed neutron sources in the world with the average power 2 MW, power per neutron pulse 1850 MW and neutron flux in pulse of 5·10 15 n/cm 2 /s. During the period December 2006 – December 2010 the reactor was on modernization for replacement of the reactor vessel and fuel elements. During 2011, the successful physical and power start-up of IBR-2M were performed. Now reactor is operational and can be used for research and development activities using neutron scattering techniques in next 25 years prospective. However, no instruments dedicated for neutron imaging is installed at IBR-2M so far. Moreover, in Russian Federation there is no dedicated neutron imaging facility for cultural heritage research at the moment

  17. Clustering methods and visualization algorithms to aid nuclear reactor operative diagnostics

    International Nuclear Information System (INIS)

    Pepelyshev, Yu.N.; Dzwinel, W.

    1990-01-01

    The software system developed plays the role of the aid to an operator for nuclear reactor diagnostics. The noise analysis of the reactor parameters such as power, temperature and coolant flow rate constitutes the basis of the system. Combination of data acquisition, data preprocessing, clustering and cluster visualization algorithms with heuristic techniques of results analysis, determine the way of its implementation. Two regimes are available. The first one - extended - is recommended for a long term investigations and the second - suppressed for the aid to the reactor operation monitoring. The system has been tested and developed at the JINR IBR-2 pulsed reactor. 13 refs.; 4 figs.; 2 tabs

  18. DN-12 time of flight neutron spectrometer for investigation of structure and dynamics of microsamples

    International Nuclear Information System (INIS)

    Savenko, B.N.; Aksenov, V.L.; Balagurov, A.M.; Kozlenko, D.P.; Sheptyakov, D.V.

    1999-01-01

    DN-12 time of flight neutron spectrometer operating at IBR-2 high flux pulsed reactor at FLNP JINR, Dubna, Russia is described. It is designed for experiments with microsamples in wide range of temperatures and pressures. DN-12 allows to perform neutron diffraction experiments at temperatures down to 15 K and pressures up to 7 Gpa and inelastic incoherent scattering experiments (with samples which have large incoherent neutron scattering cross section) at pressures up to 5 GPa with sapphire anvil high pressure cells. The parameters of the spectrometer, recent results and future prospects are reviewed. (author)

  19. Numerical generalized vibration density of states evaluation for inelastic neutron scattering in solid matter

    CERN Document Server

    Kazmianec, V; Aranghel, D

    2002-01-01

    A computational method for improved evaluation of the generalized vibration density of states (GVDS) is proposed. It is based on Fast Fourier Transform (FPT) technique and gives the possibility for more precise analyses of the neutron double differential scattering cross section. The method was applied to zirconium hydride investigation. The results were presented for ZrH sub 1 sub . sub 6 U sub 0 sub . sub 3 sub 2 sample at various temperatures on time-of-flight (TOF) Spectrometry at IBR-2 reactor of JINR-Dubna and were compared to GVDS values obtained by traditional single-phonon approximation method

  20. Determination of the origin of the medieval glass bracelets discovered in Dubna (Moscow Region, Russia), using the neutron activation analysis

    International Nuclear Information System (INIS)

    Dmitrieva, S.O.; Frontas'eva, M.V.; Dmitriev, A.Yu.; Dmitriev, A.A.

    2016-01-01

    The work is dedicated to the determination of the origin of archaeological finds from medieval glass using the method of neutron activation analysis (NAA). Among such objects we can discover things not only produced in ancient Russian glassmaking workshops but also brought from Byzantium. The authors substantiate the ancient Russian origin of the medieval glass bracelets of pre-Mongol period, found on the ancient Dubna settlement. The conclusions are based on the data about the glass chemical composition obtained as a result of NAA of ten fragments of bracelets at the IBR-2 reactor, FLNP, JINR. [ru

  1. Independent multi-channel analyzer with the color display and microcomputer in the CAMAC standard

    International Nuclear Information System (INIS)

    Gyunter, Z.; Elizarov, O.I.; Zhukov, G.P.; Mikhaehlis, B.; Shul'tts, K.Kh.

    1983-01-01

    An independent multi-channel time-of-flight analyzer developed for a spectrometer of polarised neutrons and used in experiments with the IBR-2 pulse reactor is described. Different cyclic modes of measuring are realized in the analyzer, 4 kwords of analyzer momory being assigned for each mode. The spectra are displayed on a colour screen during measurements. Simultaneous displaying of up to 8 spectra is possible. A microcomputer transfers the spectra from the buffer analyzer memory to the microcomputer memory. The accumulated information is transferred to the PDP-11/70 central computer

  2. Gamma-irradiation and neutron effect on DNA-membrane complexes of mammalian cells

    International Nuclear Information System (INIS)

    Lapidus, I.L.; Nazarov, V.M.; Ehrtsgreber, G.

    1984-01-01

    The first results of radiobiological investigations in the biophysical channel of the JINR reactor IBR-2 are presented. Sedimentation behaviour of DNA-membrane complexes has been studied at irradiation of the Chinese hamster cells (VT9-4) in a wide dose range of 137 Cs γ-irradiation and neutrons. An earlier assumption of the authors on the role of DNA double-strand breaks in changing the relative sedimentation velocity of complexes at irradiation of cells with doses over 50 Gy has been confirmed

  3. Study of residual stresses in CT test specimens welded by electron beam

    Science.gov (United States)

    Papushkin, I. V.; Kaisheva, D.; Bokuchava, G. D.; Angelov, V.; Petrov, P.

    2018-03-01

    The paper reports result of residual stress distribution studies in CT specimens reconstituted by electron beam welding (EBW). The main aim of the study is evaluation of the applicability of the welding technique for CT specimens’ reconstitution. Thus, the temperature distribution during electron beam welding of a CT specimen was calculated using Green’s functions and the residual stress distribution was determined experimentally using neutron diffraction. Time-of-flight neutron diffraction experiments were performed on a Fourier stress diffractometer at the IBR-2 fast pulsed reactor in FLNP JINR (Dubna, Russia). The neutron diffraction data estimates yielded a maximal stress level of ±180 MPa in the welded joint.

  4. Neutron scattering for analysis of processes in lithium-ion batteries

    Science.gov (United States)

    Balagurov, A. M.; Bobrikov, I. A.; Samoylova, N. Yu; Drozhzhin, O. A.; Antipov, E. V.

    2014-12-01

    The review is concerned with analysis and generalization of information on application of neutron scattering for elucidation of the structure of materials for rechargeable energy sources (mainly lithium-ion batteries) and on structural rearrangements in these materials occurring in the course of electrochemical processes. Applications of the main methods including neutron diffraction, small-angle neutron scattering, inelastic neutron scattering, neutron reflectometry and neutron introscopy are considered. Information on advanced neutron sources is presented and a number of typical experiments are outlined. The results of some studies of lithium-containing materials for lithium-ion batteries, carried out at IBR-2 pulsed reactor, are discussed. The bibliography includes 50 references.

  5. The behavior of a type-II superconductor Nb in a magnetic field as investigated in polarized-neutron transmission experiments

    International Nuclear Information System (INIS)

    Aksenov, V.L.; Dokukin, E.B.; Kozhevnikov, S.V.; Nikitenko, Yu.V.; Petrenko, A.V.

    1995-01-01

    The type-II superconducting polycrystal Nb was investigated on the SPN-1 polarized-neutron spectrometer at the high-intensity pulsed reactor IBR-2 at Dubna. In polarized-neutron transmission experiments the magnetic-field dependence of the neutron beam polarization was measured. Experiments were performed over a wide magnetic-field range from 0 to H c2 at a temperature of 4.8 K. A quasiperiodic variation of the neutron depolarization as a function of magnetic-field strength was observed. (orig.)

  6. A multisectional annular thermal-neutron detector for the study of diffraction on microsamples in axial geometry

    Science.gov (United States)

    Belushkin, A. V.; Bogdzel', A. A.; Buzdavin, A. P.; Veleshki, S. I.; Zhuravlev, A. I.; Zhuravlev, V. V.; Kichanov, S. E.; Kozlenko, D. P.; Kulikov, S. A.; Levchanovskii, F. V.; Lukin, E. V.; Milkov, V. M.; Murashkevich, S. M.; Panteleev, Ts. Ts.; Prikhod'ko, V. I.; Savenko, B. N.; Tsankov, L. T.

    2013-09-01

    A new gaseous annular sectional thermal-neutron detector for the new neutron diffractometer at the IBR-2 reactor has been designed and manufactured at the Frank Laboratory of Neutron Physics of the Joint Institute for Nuclear Research (JINR). The detector is designed to study small-volume samples at high pressure and consists of 16 sections, each one of which is divided into six independent detector elements. We present the main design features of the detector, detecting electronics, data-acquisition and visualization software, and software system for experiment management. The results of the first neutronographic experiments that were carried out with the use of the detector are also presented.

  7. Condensed medium neutron-diffraction study in JINR

    International Nuclear Information System (INIS)

    Balagurov, A.M.; Natkanets, I.; Ostanevich, Yu.M.

    1986-01-01

    A brief review of development of neutron diffraction investigations into condensed media in JINR is given. Structural neutron diffraction and dynamics of condensed media are considered. Commissioning of the IBR-2 reactor allowed one to investigate segnetoelectric and segnetoelastic crystals, conduct first experiments on neutron diffraction, using a monocrystal of myoglobin muscle protein. Texture neutron diffraction method is being developed. Simultaneously with the start-up activities, development of methods for experiments on the neutron inelastic scattering has begun. Two different experimental problems were solved: elementary excitation spectrum investigation and search for Bose-condensate. The growth of the JINR science and technology potential is accompanied by a rapid expansion of international cooperation

  8. Activation analysis of coal with the help of a microtron

    International Nuclear Information System (INIS)

    Sodnom, N.; Gehrbish, Sh.

    1989-01-01

    Activation analysis techniques using microtron bremsstrahlung and photoneutrons have been developed for the multielemental analysis of coal. Analysis data for coals from 17 mines of Mongolia are presented. The chlorine content of coal and the distribution of elements in coal burning products are determined. Control experiments were performed at the reactors IBR-2 and ARGUS. The results of the gamma activation analysis are compared with neutron activation and X-ray fluorescence analyses data. It is shown that the microtron irradiation techniques employed provide a satisfactory multielemental basis for the analysis of coal. (author)

  9. The dynamic method for time-of-flight measurement of thermal neutron spectra from pulsed sources

    International Nuclear Information System (INIS)

    Pepyolyshev, Yu.N.; Chuklyaev, S.V.; Tulaev, A.B.; Bobrakov, V.F.

    1995-01-01

    A time-of-flight method for measurement of thermal neutron spectra in pulsed neutron sources with an efficiency more than 10 5 times higher than the standard method is described. The main problems associated with the electric current technique for time-of-flight spectra measurement are examined. The methodical errors, problems of special neutron detector design and other questions are discussed. Some experimental results for spectra from the surfaces of water and solid methane moderators obtained at the IBR-2 pulsed reactor (Dubna, Russia) are presented. (orig.)

  10. Análise paramétrica de um reator anelar pulsado

    OpenAIRE

    Muniz da Silva, Helmut

    2006-01-01

    Um conceito de reator pulsado denominado VICHFPR (Very Intense Continuous Flux Pulsed Reactor) foi apresentado em 1997 como uma possível extensão do reator periodicamente pulsado russo IBR-2. O núcleo desse reator tem geometria anelar e é percorrido por um modulador de reatividade que é responsável pelo surgimento de um pulso rotativo no fluxo neutrônico no reator. Enquanto a maior parte do núcleo opera na subcriticalidade (kef1+β), gerando um fluxo máximo bem maior do que o fluxo médio....

  11. System of common usage on the base of external memory devices and the SM-3 computer

    International Nuclear Information System (INIS)

    Baluka, G.; Vasin, A.Yu.; Ermakov, V.A.; Zhukov, G.P.; Zimin, G.N.; Namsraj, Yu.; Ostrovnoj, A.I.; Savvateev, A.S.; Salamatin, I.M.; Yanovskij, G.Ya.

    1980-01-01

    An easily modified system of common usage on the base of external memories and a SM-3 minicomputer replacing some pulse analysers is described. The system has merits of PA and is more advantageous with regard to effectiveness of equipment using, the possibility of changing configuration and functions, the data protection against losses due to user errors and some failures, price of one registration channel, place occupied. The system of common usage is intended for the IBR-2 pulse reactor computing centre. It is designed using the SANPO system means for SM-3 computer [ru

  12. Determination of the origin of the medieval glass bracelets discovered in Dubna, Moscow Region, Russia, using the neutron activation analysis

    International Nuclear Information System (INIS)

    Dmitrieva, S.O.; Frontasyeva, M.V.; Dmitriev, A.Yu.; Dmitriev, A.A.

    2017-01-01

    The work is dedicated to the determination of the origin of archaeological finds from medieval glass using the method of neutron activation analysis (NAA). Among such objects we can discover things not only produced in ancient Russian glassmaking workshops but also imported from Byzantium. The authors substantiate the ancient Russian origin of the medieval glass bracelets of pre-Mongol period, found on the ancient Dubna settlement. The conclusions are based on data on the glass chemical composition obtained as a result of NAA of 10 fragments of bracelets at the IBR-2 reactor, FLNP, JINR.

  13. Neutron activation of building materials used in the reactor shield

    International Nuclear Information System (INIS)

    Hernandez, A.T.; Perez, G.; D'Alessandro, K.

    1993-01-01

    Cuban concretes and their main components (mineral aggregates and cement) were investigated through long-lived activation products induced by neutrons from a reactor. The multielemental content in the materials studied was obtained by neutron activation analysis in an IBR-2 reactor and gamma activation analysis in an MT-25 microtron from Join Institute of Nuclear Research of Dubna. After irradiation of building materials for 30 years by a neutron flow of unitary density, induced radioactivity was calculated according to experimental data. The comparative evaluation of different concretes aggregates and two types of cement related to the activation properties is discussed

  14. A new species of Western Atlantic sea lily in the family Bathycrinidae (Echinodermata: Crinoidea), with a discussion of relationships between crinoids with xenomorphic stalks.

    Science.gov (United States)

    Mironov, Alexandr N; Pawson, David L

    2014-10-16

    A new species in the family Bathycrinidae is described from abyssal depths from the Bahamas. It is referred to the recently established genus Discolocrinus, which formerly comprised a single species D. thieli Mironov, 2008 from the Eastern Pacific. Discolocrinus iselini n. sp. is characterized by large body size, high tegmen with tube-like upper region, extremely elongated IBr1 and IBr2, large knobby processes on primibrachials, and overgrowth of soft tissue on the pinnules, the tissue containing numerous perforated or imperforate ossicles of varying size and form. Differences between Discolocrinus and other bathycrinids may seem to be of taxonomic importance at the family level, but knowledge of the morphology and variability of both species of Discolocrinus is incomplete and, until a richer material becomes available, the genus should remain in family Bathycrinidae. Representatives of five families with xenomorphic stalks were examined to characterize the genera on the basis of number or form of knobby processes. These processes occur in two families with differing external morphology: ten-armed Bathycrinidae and five-armed Bourgueticrinidae. They also occur in the comatulid family Atelecrinidae. This similarity might seem to indicate a close relationship between the three families. However, morphological analysis supports the separation of the families Caledonicrinidae and Septocrinidae from Bathycrinidae despite the fact that they share a xenomorphic stalk and IBr2ax. These conclusions are in agreement with results of recent molecular studies.

  15. Stability of the Hall sensors performance under neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Duran, I.; Hron, M.; Stockel, J. [Institute of Plasma Physics, Association EURATOM/IPP.CR, Praha (Czech Republic); Viererbl, L.; Vsolak, R.; Cerva, V. [Nuclear Research Institute plc (Czech Republic); Bolshakova, I.; Holyaka, R. [Lviv Polytechnic National Univ. (Ukraine); Vayakis, G. [ITER International Team, Naka Joint Work Site, Naka, Ibaraki (Japan)

    2004-07-01

    A principally new diagnostic method must be developed for magnetic measurements in steady state regime of operation of fusion reactor. One of the options is the use of transducers based on Hall effect. The use of Hall sensors in ITER is presently limited by their questionable radiation and thermal stability. Issues of reliable operation in ITER like radiation and thermal environment are addressed in the paper. The results of irradiation tests of candidate Hall sensors in LVR-15 and IBR-2 experimental fission reactors are presented. Stable operation (deterioration of sensitivity below one percent) of the specially prepared sensors was demonstrated during irradiation by the total fluence of 3.10{sup 16} n/cm{sup 2} in IBR-2 reactor. Increasing the total neutron fluence up to 3.10{sup 17} n/cm{sup 2} resulted in deterioration of the best sensor's output still below 10% as demonstrated during irradiation in LVR-15 fission reactor. This level of neutron is already higher than the expected ITER life time neutron fluence for a sensor location just outside the ITER vessel. (authors)

  16. Atmospheric deposition of trace elements around Ulan Bator city studied by moss and lichen biomonitoring technique and INAA

    International Nuclear Information System (INIS)

    Ganbold, G.; Gehrbish, Sh.; Tsehndehehkhuu, Ts.; Gundorina, S.F.; Frontas'eva, M.V.; Ostrovnaya, T.M.; Pavlov, S.S.

    2005-01-01

    For the first time the moss and lichen biomonitoring technique has been applied to air pollution in Mongolia (Ulan-Bator, the capital city). INAA at the IBR-2 reactor has made it possible to determine the content of 35 elements in moss and lichen biomonitors. Samples collected at sites located 10-15 km from the center of Ulan-Bator were analyzed by Instrumental Neutron Activation Analysis (INAA) using epithermal neutrons. The mosses (Rhytidium rugosum, Thuidium abietinum, Entodon concinnus) and lichens (Cladonia stellaris, Parmelia separata) were used to study the atmospheric deposition of trace elements. It was shown that the suggested types of mosses could be used as suitable biomonitors to estimate the concentration levels of heavy metals and trace elements in Ulan-Bator atmospheric deposition. The results are compared to the data of atmospheric deposition of some European countries

  17. Influence of neutron irradiation on magnetic field sensors

    CERN Document Server

    Karpukhin, A V; Makoveev, V K; Zamiatin, N I; Bolshakova, I A; Bolshakov, M M; Matkovski, A O; Moskovets, T A

    2000-01-01

    Parameters of modern experimental set-ups depend on the precision of the magnetic field monitoring under real experimental conditions. As a rule, the conditions of modern experiments (ATLAS, CMS, ALICE, LHC- B) have their special requirements to radiation hardness of the magnetometric apparatus. Specialized magnetic-calibration stands have been manufactured to investigate magnetic field sensors for radiation hardness at the Joint Institute for Nuclear Research (JINR) and at the State University "Lviv Politechnic" (SULP). Characteristics of different magnetic field sensors were studied before and after exposure. The sensors were irradiated at the IBR-2 reactor, JINR, by fast neutrons with the mean energy =1.35 MeV up to the fluence of 10/sup 19/ n/m/sup 2/. (3 refs).

  18. Temperature dependence of the lattice parameter and Debye-Waller factor of a high-chromium pressure-vessel steel

    Science.gov (United States)

    Sumin, V. V.; Simkin, V. G.; Sheverev, S. G.; Leont'eva-Smirnova, M. V.; Chernov, V. M.

    2009-12-01

    The method of thermal neutron diffraction has been used to study samples of the EK-181 steel at temperatures of 15 to 973 K in an IBR-2 reactor (Joint Institute for Nuclear Research (JINR)). Temperature dependences of the lattice parameter, internal textural stresses (of the third kind), and the Debye-Waller factor of this steel have been calculated from diffraction spectra by the Rietveld method. It has been found that at low temperatures the temperature dependence of the lattice parameter in the EK-181 steel (RUSFER EK-181) differs from the corresponding dependence in pure iron and binary iron-chromium alloys containing 12 and 16% Cr. Also, a broadening of the ( 200) reflection has been observed in the diffraction spectra of the EK-181 steel and the Fe-12Cr alloy, while it is not detected in the spectra of Fe-16Cr and pure iron.

  19. X – ray and neutron diffraction of TiAl alloys

    International Nuclear Information System (INIS)

    Valkov, Stefan; Petrov, Peter; Neov, Dimitar; Beskrovny, Anatoly; Kozlenko, Denis

    2015-01-01

    TiAl alloys were prepared by electron beam hybrid method. Composite Ti-Al film, from composite target, was deposited on Ti substrate by electron beam evaporation, followed by electron beam treatment with scanning electron beam. Experiments were made using Leybold Heraus (EWS 300/ 15 - 60) with the following technological parameters : accelerating voltage U = 60kV; beam current I=40 mA, speed of movement of specimens V=5 cm/s, current of the focusing lens If =512mA, specimen distance D0 = 38cm. X- ray and neutron diffraction methods were used to determine the phase composition on the surface and at the volume, respectively. Time of flight neutron diffraction study of TiAl specimens was performed on DN-2 diffractometer at fast pulsed IBR-2 reactor in FLNP JINR (Dubna, Russia).We found that intermetallic TiAl phases were successfully obtained on the surface, as well as in the volume.

  20. Pattern recognition, neural networks, genetic algorithms and high performance computing in nuclear reactor diagnostics. Results and perspectives

    International Nuclear Information System (INIS)

    Dzwinel, W.; Pepyolyshev, N.

    1996-01-01

    The main goal of this paper is the presentation of our experience in development of the diagnostic system for the IBR-2 (Russia - Dubna) nuclear reactor. The authors show the principal results of the system modifications to make it work more reliable and much faster. The former needs the adaptation of new techniques of data processing, the latter, implementation of the newest computational facilities. The results of application of the clustering techniques and a method of visualization of the multi-dimensional information directly on the operator display are presented. The experiences with neural nets, used for prediction of the reactor operation, are discussed. The genetic algorithms were also tested, to reduce the quantity of data nd extracting the most informative components of the analyzed spectra. (authors)

  1. Prompt fission neutron investigation in 235U(nth,f) reaction

    Science.gov (United States)

    Zeynalov, Shakir; Sedyshev, Pavel; Shvetsov, Valery; Sidorova, Olga

    2017-09-01

    The prompt neutron emission in thermal neutron induced fission of 235U has been investigated applying digital signal electronics. The goal was to compare the results of this digital data acquisition and digital signal processing analysis to the results of the pioneering work of Apalin et al. Using a twin Frisch grid ionization chamber for the fission fragment detection and a NE213 equivalent neutron detector in total about 106 neutron coincidences have been registered. The fission fragment kinetic energy, mass and angular distribution has been investigated along with prompt neutron time of flight and pulse shape using a six channel synchronous waveform digitizer with sampling frequency of 250 MHz and 12 bit resolution. The signals have been analyzed using digital pulse processing algorithms, developed by authors. The thermal neutron beam was transported from the IBR-2 reactor to the target with bent mirror neutron guide.

  2. Prompt fission neutron investigation in 235U(nth,f reaction

    Directory of Open Access Journals (Sweden)

    Zeynalov Shakir

    2017-01-01

    Full Text Available The prompt neutron emission in thermal neutron induced fission of 235U has been investigated applying digital signal electronics. The goal was to compare the results of this digital data acquisition and digital signal processing analysis to the results of the pioneering work of Apalin et al. Using a twin Frisch grid ionization chamber for the fission fragment detection and a NE213 equivalent neutron detector in total about 106 neutron coincidences have been registered. The fission fragment kinetic energy, mass and angular distribution has been investigated along with prompt neutron time of flight and pulse shape using a six channel synchronous waveform digitizer with sampling frequency of 250 MHz and 12 bit resolution. The signals have been analyzed using digital pulse processing algorithms, developed by authors. The thermal neutron beam was transported from the IBR-2 reactor to the target with bent mirror neutron guide.

  3. Detector for the FSD Fourier-Diffractometer Based on ZnS(Ag)/^{6}LiF Scintillation Screen and Wavelength Shifting Fibers Readout

    CERN Document Server

    Kuzmin, E S; Bokuchava, G D; Zhuk, V V; Kudryashov, V A; Buklin, A P; Trounov, V A

    2001-01-01

    At the IBR-2 pulsed reactor (FLNP, JINR, Dubna), a specialized time-of-flight instrument Fourier-Stress-Diffractometer (FSD) intended for the measurement of internal steresses in bulk samples by using high-resolution neutron diffraction is under construction. One of the main components of the diffractometer is a new-type detector with combined electronic - geometrical focusing uniting a large solid angle and a small geometry contribution to the instrumental resolution. The first two modules of the detector, based on scintillation screen ZnS(Ag)/^{6}LiF with wavelength shifting fibers readout have been developed and tested. The design of the detector and associated electronics are described. The method of time focusing surface approximation, using the screen flexibility is proposed. Characteristics of tested modules in comparison with a detector of previous generation are presented and advantages of new detector design for high-resolution diffractometry are discussed.

  4. New results from air pollution studies in Bulgaria (moss survey 2000-2001)

    International Nuclear Information System (INIS)

    Stamenov, J.; Jovchev, M.; Vachev, B.

    2002-01-01

    New results of moss survey 2000 of systematic study of air pollution with heavy metals and other toxic elements in Bulgaria are reported. The moss samples collected at 103 sites in Bulgaria, along the borders with Yugoslavia, Macedonia, Greece and Turkey were analyzed by instrumental activation analysis using epithermal neutrons (ENAA) at the IBR-2 pulsed fast reactor for a wide set of elements including heavy metals and rare earth elements (Na, Mg, Al, Cl, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Br, Rb, Sr, Mo, Sb, I, Cs, Ba, La, Sm, Tb, Yb, Hf, Ta, W, Au, Th, and U). The results obtained are consistent with the mean European values for most of elements. The principle component analysis is applied to distinguish heavy and light crust elements and vegetation ones from those of anthropogenic origin

  5. Metal Hall sensors for the new generation fusion reactors of DEMO scale

    Science.gov (United States)

    Bolshakova, I.; Bulavin, M.; Kargin, N.; Kost, Ya.; Kuech, T.; Kulikov, S.; Radishevskiy, M.; Shurygin, F.; Strikhanov, M.; Vasil'evskii, I.; Vasyliev, A.

    2017-11-01

    For the first time, the results of on-line testing of metal Hall sensors based on nano-thickness (50-70) nm gold films, which was conducted under irradiation by high-energy neutrons up to the high fluences of 1 · 1024 n · m-2, are presented. The testing has been carried out in the IBR-2 fast pulsed reactor in the neutron flux with the intensity of 1.5 · 1017 n · m-2 · s-1 at the Joint Institute for Nuclear Research. The energy spectrum of neutron flux was very close to that expected for the ex-vessel sensors locations in the ITER experimental reactor. The magnetic field sensitivity of the gold sensors was stable within the whole fluence range under research. Also, sensitivity values at the start and at the end of irradiation session were equal within the measurement error (fusion reactors of DEMO scale.

  6. Neutron diffraction investigation of an in-plane biaxial fatigued stainless steel sample of cruciform geometry

    Science.gov (United States)

    Taran, Yu V.; Balagurov, A. M.; Sheverev, S. G.; Schreiber, J.; Korsunsky, A. M.; Vorster, W. J. J.; Bomas, H.; Stoeberl, C.

    2008-03-01

    Fatigue and fracture under multiaxial stresses are among the most important current research topics aimed at ensuring improved reliability of industrial components. An ex situ in-plane biaxial low cycle fatigued sample of cruciform geometry from austenitic stainless steel AISI 321 H was investigated on the FSD stress-diffractometer at the IBR-2 pulsed nuclear reactor by using the neutron strain scanner and the uniaxial stress rig. The phase composition of fatigued material was determined and the residual macrostresses and phase microstresses were measured. To the best of our knowledge, no neutron diffraction investigations of materials subjected to biaxial loading have been previously carried out. The first results of the neutron diffraction experiment are presented and discussed.

  7. Relation between sedimentation behaviour of DNA-membrane complexes and DNA single- and double-strand breaks after irradiation with gamma-rays, pulse neutrons and 12C ions

    International Nuclear Information System (INIS)

    Erzgraber, G.; Lapidus, I.L.

    1985-01-01

    The experimental data on sedimentation behaviour of DNA-membrane complexes at radiation of the Chinese hamster cells (V79-4) in a wide dose range of 127 Cs γ-rays, pulse neutrons (reactor IBR-2, Laboratory of Neutron Physics, JINR, Dubna) are accelerated 12 C ions (cyclotron U-200, Laboratory of Nuclear Reactions, JINR, Dubna) are presented An assumption on the role of DNA single- and double-strend breaks in changing the sedimentation properties of DNA-membrane complexes has been confirmed by the experiments with radiation of different quality. The possibility of estimating induction and repair of DNA breaks on the basis of dependence of the relative sedimentation velocity of complexes on the irradiation does is discussed

  8. A New approach for the data acquisition system of the cairo fourier diffractometer

    International Nuclear Information System (INIS)

    Maayouf, R.M.A.; Khalil, M.I.

    2000-01-01

    The present work deals with a new approach for the reverse time of flight (RTOF) analysis of the diffraction spectra. The approach is based on the same RTOF concept used for the design of a separate RTOF analyzer and applies, for data acquisition, a special interface card and software program installed in a PC computer, to perform the cross-correlation functions between the three signals received from the chopper decoder, detector and the pulsed neutron source respectively. The new approach have been realized for use with a Fourier diffractometer facility based on the RTOF concept. It has been found from test measurements performed with the high resolution Fourier diffractometer (HRFD) at the IBR-2 reactor (JINR, Dubna) that the new approach can successfully replace the RTOF analyzer

  9. High-temperature investigation of the dynamics and thermodynamics of ZrH-U system by neutron scattering

    International Nuclear Information System (INIS)

    Padureanu, I.; Rapeanu, S.N.; Radulescu, A.; Kozlov, Zh.A.; Semenov, V.A.

    2001-01-01

    Inelastic neutron scattering (INS) measurements of the vibrational frequencies in δ-Zr hydride containing uranium, ZrH 1.6 U 0.32 , have been performed in the range of high temperatures (between 293 and 973 K) at the DIN-2PI time-of-flight spectrometer at the IBR-2 pulsed reactor of JINR, Dubna. From the temperature dependence of the generalized vibrational density of states (GVDS), information on the H potential has been obtained. Also the high frequency limit of lattice vibrations as well as the frequency of optical vibrations have been studied as functions of temperature. Starting from basic properties, the main thermodynamic functions, the characteristic Debye and Einstein temperatures and the total specific heat have been derived. (orig.)

  10. High Temperature Investigation of the Dynamics and the Thermodynamics of ZrH-U System by Neutron Scattering

    CERN Document Server

    Padureanu, I; Rotarescu, C; Semenov, V A; Radulescu A

    2000-01-01

    Inelastic neutron scattering (INS) measurements of the vabrational frequencies in delta-Zr hydride containing uranium, ZrH_{1.6}U_{0.32}, have been performed in the range of high temperatures, between 293 and 973 K, at DIN-2PI time-of-flight spectrometer, IBR-2 pulsed reactor of JINR-Dubna. From the temperature dependence of the generalized vibrational density of states (GVDS), information about the H potential have been obtained and also high frequency limit of the lattice vibrations and frequency of optical vabrations have been studied as functions of temperature. Starting from the basic properties, the main thermodynamic functions, the characteristic Debye and Einstein temperatures and the total specific heat have been derived.

  11. High temperature investigation of the dynamics and the thermodynamics of ZrH-U system by neutron scattering

    International Nuclear Information System (INIS)

    Padureanu, I.; Rotarescu, Ch.; Radulescu, A.; Kozlov, Zh.A.; Semenov, V.A.

    2000-01-01

    Inelastic neutron scattering (INS) measurements of the vibrational frequencies in δ - Zr hydride containing uranium, ZrH 1.6 U 0.32 , have been performed in the range of high temperatures, between 293 and 973 K, at DIN-2PI time-of-flight spectrometer, IBR-2 pulsed reactor of JINR-Dubna. From the temperature dependence of the generalized vibrational density of states (GVDS), information about the H potential has been obtained and also high frequency limit of the lattice vibrations and frequency of optical vibrations have been studied as functions of temperature. Starting from the basic properties, the main thermodynamic functions, the characteristic Debye and Einstein temperatures and the total specific heat have been derived

  12. Neutron diffraction investigation of an in-plane biaxial fatigued stainless steel sample of cruciform geometry

    International Nuclear Information System (INIS)

    Taran, Yu V; Balagurov, A M; Sheverev, S G; Schreiber, J; Korsunsky, A M; Vorster, W J J; Bomas, H; Stoeberl, C

    2008-01-01

    Fatigue and fracture under multiaxial stresses are among the most important current research topics aimed at ensuring improved reliability of industrial components. An ex situ in-plane biaxial low cycle fatigued sample of cruciform geometry from austenitic stainless steel AISI 321 H was investigated on the FSD stress-diffractometer at the IBR-2 pulsed nuclear reactor by using the neutron strain scanner and the uniaxial stress rig. The phase composition of fatigued material was determined and the residual macrostresses and phase microstresses were measured. To the best of our knowledge, no neutron diffraction investigations of materials subjected to biaxial loading have been previously carried out. The first results of the neutron diffraction experiment are presented and discussed

  13. Investigation of rail wheel steel crystallographic texture changes due to modification and thermomechanical treatment

    Science.gov (United States)

    Lychagina, T.; Nikolayev, D.; Sanin, A.; Tatarko, J.; Ullemeyer, K.

    2015-04-01

    In this work crystallographic texture for a set of rail wheel steel samples with different regimes of thermo-mechanical treatment and with and without modification by system Al-Mg-Si- Fe-C-Ca-Ti-Ce was measured by neutron diffraction. The texture measurements were carried out by using time-of-flight technique at SKAT diffractometer situated at IBR-2 reactor (Dubna, JINR, Russia). The three complete pole figures (110), (200), (211) of α-Fe phase in 5°×5°grid were extracted from a set of 1368 spectra measured for each sample. The samples were cut from rail wheel rim and from transitional zone (between rail wheel hub and wheel disk). It was concluded that the steel modification and some changes in the heat treatment modes of the rail wheels from the experimental (modified) and the conventional (non-modified) steel lead to reorientation of texture component.

  14. Neutron diffraction studies of laser welding residual stresses

    Science.gov (United States)

    Petrov, Peter I.; Bokuchava, Gizo D.; Papushkin, Igor V.; Genchev, Gancho; Doynov, Nikolay; Michailov, Vesselin G.; Ormanova, Maria A.

    2016-01-01

    The residual stress and microstrain distribution induced by laser beam welding of the low-alloyed C45 steel plate was investigated using high-resolution time-of-flight (TOF) neutron diffraction. The neutron diffraction experiments were performed on FSD diffractometer at the IBR-2 pulsed reactor in FLNP JINR (Dubna, Russia). The experiments have shown that the residual stress distribution across weld seam exhibit typical alternating sign character as it was observed in our previous studies. The residual stress level is varying in the range from -60 MPa to 450 MPa. At the same time, the microstrain level exhibits sharp maxima at weld seam position with maximal level of 4.8·10-3. The obtained experimental results are in good agreement with FEM calculations according to the STAAZ model. The provided numerical model validated with measured data enables to study the influence of different conditions and process parameters on the development of residual welding stresses.

  15. New Results from Air Pollution Studies in Bulgaria (Moss Survey 2000-2001)

    CERN Document Server

    Stamenov, J N; Vachev, B; Gueleva, E; Yurukova, L; Ganeva, A; Mitrikov, M; Antonov, A; Srentz, A; Varbanov, Z; Batov, I V; Damov, K; Marinova, E; Frontasyeva, M V; Pavlov, S S; Strelkova, L P

    2002-01-01

    New results of moss survey 2000 of systematic study of air pollution with heavy metals and other toxic elements in Bulgaria are reported. The moss samples collected at 103 sites in Bulgaria, along the borders with Yugoslavia, Macedonia, Greece and Turkey were analyzed by instrumental activation analysis using epithermal neutrons (ENAA) at the IBR-2 pulsed fast reactor for a wide set of elements including heavy metals and rare earth elements (Na, Mg, Al, Cl, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Br, Rb, Sr, Mo, Sb, I, Cs, Ba, La, Sm, Tb, Yb, Hf, Ta, W, Au, Th, and U). The results obtained are consistent with the mean European values for most of elements. The principle component analysis is applied to distinguish heavy and light crust elements and vegetation ones from those of anthropogenic origin.

  16. Neutron Diffraction Study of the High-Tc Superconductor HgBa2CaCu2O6.3 under High Pressure

    International Nuclear Information System (INIS)

    Aksenov, V.L.; Balagurov, A.M.; Savenko, B.N.; Capponi, J.J.; Glazkov, V.P.; Goncharenko, I.N.; Somenkov, V.A.

    1994-01-01

    The pressure dependence of the crystal structure of a powder sample of HgBa 2 CaCu 2 O 6.3 (T c =123 K) was studied in the pressure range of 0 to 3.6 GPa, using the DN-12 time-of-flight diffractometer at the IBR-2 pulsed reactor and a sapphire anvil cell chamber. At P=0 the results are in a good accordance with the published data. At P=3.0 and 3.6 GPa the best fit of the experimental data was achieved using the structural model with apical oxygen disordered in the (a,b) plane. The compressibility values of the lattice constants and selected bonds were calculated from the structural data. The highest absolute value of compressibility was found for the distance between the O atom layers. 12 refs., 6 figs., 3 tabs

  17. Experimental study of swelling of irradiated solid methane during annealing

    International Nuclear Information System (INIS)

    Shabalin, E.; Fedorov, A.; Kulagin, E.; Kulikov, S.; Melikhov, V.; Shabalin, D.

    2008-01-01

    Solid methane is still widely in use at pulsed neutron sources due to its excellent neutronic performance (IPNS, KENS, Second Target Station at ISIS), notwithstanding poor radiation properties. One of the specific problems is radiolytic hydrogen gas pressure on the walls of a methane chamber during annealing of methane. In this paper results of an experimental study of this phenomenon under fast neutron irradiation with the help of a specially made low temperature irradiation rig at the IBR-2 pulsed reactor are presented. The peak pressure on the wall of the experimental capsule during heating of a sample irradiated at 23-35 K appears to have a maximum of 2.7 MPa at an absorbed dose 20 MGy and then falls down with higher doses. The pressure always reached its peak value at the temperature range 72-79 K. Generally, three phases of methane swelling during heating can be distinguished, each characterized by a proper rate and intensity.

  18. Description of the structural evolution of a hydrating portland cement paste by SANS

    International Nuclear Information System (INIS)

    Haeussler, F.; Eichhorn, F.; Baumbach, H.

    1994-01-01

    On the spectrometer MURN at the pulsed reactor IBR-2 dry Portland cement, silica fume, and a hydrating Portland cement paste were studied by small-angle neutron scattering (SANS). By using the TOF-method a momentum transfer from 0.07 nm -1 to 7 nm -1 is detectable. Every component (dry cement powder, clinker minerals, hydrating cement pastes) shows a different scattering behaviour. In the measured Q-region the hardening cement paste does not show a Porod-like behaviour of SANS-curves. In contrast the Porod's potential law holds for dry powder samples of clinker minerals and silica fume. In experiments carried out to observe the hydration progress within the first 321 days the characteristics of the scattering curves (potential behaviour, the radius of gyration, and the macroscopic scattering cross section at Q = 0 nm -1 were measured. Some evolution of the inner structure of the hardened cement paste was noted. (orig.)

  19. Atmospheric Deposition of Trace Elements Around Ulan-Bator City Studied by Moss and Lichen Biomonitoring Technique and INAA

    CERN Document Server

    Ganbold, G; Gundorina, S F; Frontasyeva, M V; Ostrovnaya, T M; Pavlov, S S; Tsendeekhuu, T

    2005-01-01

    For the first time the moss and lichen biomonitoring technique has been applied to air pollution in Mongolia (Ulan-Bator, the capital city). INAA at the IBR-2 reactor has made it possible to determine the content of 35 elements in moss and lichen biomonitors. Samples collected at sites located 10-15 km from the center of Ulan-Bator were analyzed by Instrumental Neutron Activation Analysis (INAA) using epithermal neutrons. The mosses (\\textit{Rhytidium rugosum}, \\textit{Thuidium abietinum}, \\textit{Entodon concinnus}) and lichens (\\textit{Cladonia stellaris}, \\textit{Parmelia separata}) were used to study the atmospheric deposition of trace elements. It was shown that the suggested types of mosses could be used as suitable biomonitors to estimate the concentration levels of heavy metals and trace elements in Ulan-Bator atmospheric deposition. The results are compared to the data of atmospheric deposition of some European countries.

  20. Concentration of elements in atmospheric aerosol in Bratislava

    International Nuclear Information System (INIS)

    Meresova, J.; Florek, M.; Holy, K.; Sykora, I.; Frontasyeva, M.V.; Pavlov, S.S.

    2006-01-01

    The concentrations of 41 chemical elements (heavy metals, rare earths, and actinides) were determined in atmospheric aerosol using nuclear and related analytical techniques. The sampling location in Bratislava (Slovak Republic). The main goal of this study is the quantification of the atmospheric pollution and its trend. The elemental content in filters was measured using instrumental neutron activation analysis at IBR-2 reactor in JINR Dubna and by atomic absorption spectrometry in Bratislava. The obtained results confirm the decreasing trend of pollution by most of the heavy metals in Bratislava atmosphere, and they are compared with the contents of pollutants in atmosphere of other cities. We determined also the composition of clear filter materials. (Authors)

  1. Mechanistic aspects of the reaction between Br2 and chalcogenone donors (LE; E=S, Se): competitive formation of 10-E-3, T-shaped 1:1 molecular adducts, charge-transfer adducts, and [ (LE)2]2+ dications.

    Science.gov (United States)

    Aragoni, M C; Arca, M; Demartin, F; Devillanova, F A; Garau, A; Isaia, F; Lelj, F; Lippolis, V; Verani, G

    2001-07-16

    parallel planes; this gives rise to a graphite-like stacking. The new crystalline modification of 10, obtained from acetonitrile solution, confirms the importance of short intermolecular contacts in determining the asymmetry of Br-E-Br (E = S, Se) and I-Se-I groups in hypervalent 10-E-3 compounds. The analogies in the conductometric and spectrophotometric titrations of 1 and 2-4 with Br2, together with the similarity of the vibrational spectra of 11-14, also imply a T-shaped nature for 11. The vibrational properties of the Br-E-Br (E = S, Se) systems resemble those of the Br3- and IBr2- anions: the Raman spectrum of a symmetric Br-E-Br group shows only one peak near 160 cm(-1), as found for symmetric Br3- and IBr2- anions, while asymmetric Br-E-Br groups also show an antisymmetric Br-E-Br mode at around 190 cm(-1), as observed for asymmetric Br3- and IBr2- ions. Therefore, simple IR and Raman measurements provide a useful tool for distinguishing between symmetric and asymmetric Br-E-Br groups, and hence allow predictions about the crystal packing of these hypervalent chalcogen compounds to be made when crystals of good quality are not available.

  2. Methods and instrumentation for investigating Hall sensors during their irradiation in nuclear research reactors

    International Nuclear Information System (INIS)

    Bolshakova, I.; Holyaka, R.; Makido, E.; Marusenkov, A.; Shurygin, F.; Yerashok, V.; Moreau, P. J.; Vayakis, G.; Duran, I.; Stockel, J.; Chekanov, V.; Konopleva, R.; Nazarkin, I.; Kulikov, S.; Leroy, C.

    2009-01-01

    Present work discusses the issues of creating the instrumentation for testing the semiconductor magnetic field sensors during their irradiation with neutrons in nuclear reactors up to fluences similar to neutron fluences in steady-state sensor locations in ITER. The novelty of the work consists in Hall sensor parameters being investigated: first, directly during the irradiation (in real time), and, second, at high irradiation levels (fast neutron fluence > 10 18 n/cm 2 ). Developed instrumentation has been successfully tested and applied in the research experiments on radiation stability of magnetic sensors in IBR-2 (JINR, Dubna) and VVR-M (PNPI, Saint-Petersburg) reactors. The 'Remote-Rad' bench consists of 2 heads (head 1 and head 2) bearing investigated sensors put in a ceramic setting, of electronic unit, of personal computer and of signal lines. Each head contains 6 Hall sensors and a coil for generating test magnetic field. Moreover head 1 contains thermocouples for temperature measurement while the temperature of head 2 is measured by thermo-resistive method. The heads are placed in the reactor channel

  3. Atmospheric depositions of rare earth elements in Albania studied by the moss biomonitoring technique, neutron activation analysis and GIS technology

    International Nuclear Information System (INIS)

    Allajbeu, Sh.; Lazo, P.; Yushin, N.S.; Frontasyeva, M.V.; Qarri, F.; Duliu, O.G.

    2015-01-01

    Rare earth elements (REE) are conservative elements, scarcely derived from anthropogenic sources. The mobilization of REE in the environment requires their monitoring in environmental matrices, where they are mainly present at trace levels. The results on determination of the content of 11 elements by epithermal neutron activation analysis (ENAA) at the IBR-2 reactor in Dubna in carpet-forming moss species Hypnum cupressiforme collected from 44 sampling sites over the whole Albanian territory are presented and discussed. The paper is focused on Sc and lanthanides, as well as Fe and Th, the last ones showing correlations with the investigated REE. With the exception of Fe, all other elements were never determined in the air deposition of Albania. The STATISTICA TM 10 software was used for data analysis. The median values for the content of elements under investigation were compared to those in Bulgaria, Macedonia, Romania and Serbia, as well as Norway selected as a pristine area. Therefore, it was shown that the accumulation of REE in mosses is associated with the wind blown metal-enriched soils that are pointed out as the main emitting factor. [ru

  4. An accurate redetermination of the sup 1 sup 1 sup 8 Sn binding energy

    CERN Document Server

    Borzakov, S B; Faikow-Stanczyk, H; Grigoriev, Y V; Panteleev, T; Pospísil, S; Smotritsky, L M; Telezhnikov, S A

    2002-01-01

    The energy of well-known strong gamma line from sup 1 sup 9 sup 8 Au, the 'gold standard', has been modified in the light of new adjustments in the fundamental constants and the value of 411.80176(12) keV was determined, which is 0.29 eV lower than the latest 1999 value. An energy calibration procedure for determining the neutron binding energy, B sub n , from complicated (n, gamma) spectra has been developed. A mathematically simple minimization function consisting only of terms having as parameters the coefficients of the energy calibration curve (polynomial) is used. A priori information about the relationships among the energies of different peaks on the spectrum is taken into account by a Monte-Carlo simulation. The procedure was used in obtaining B sub n for sup 1 sup 1 sup 8 Sn. The gamma-ray spectrum from thermal neutron radiative capture by sup 1 sup 1 sup 7 Sn has been measured on the IBR-2 pulsed reactor. gamma-rays were detected by a 72 cm sup 3 HPGe detector. For a better determination of B sub n...

  5. An Accurate Redetermination of the $^{118}Sn$ Binding Energy

    CERN Document Server

    Borzakov, S B; Faikow-Stanczyk, H; Grigoriev, Yu V; Panteleev, T; Pospísil, S; Smotritsky, L M; Telezhnikov, S A

    2001-01-01

    The energy of well-known strong {gamma}-line from {{^198}Au}, the "gold standard", has been modified in the light of new adjustments in the fundamental constants and the value of 411.80176(12) keV was determined which is 0.29 eV lower than the latest 1999 value. An energy calibration procedure for determining the neutron binding energy, {B_n}, from complicated {(n , gamma)}-spectra has been developed. A mathematically simple minimization function consisting only of terms having as parameters the coefficients of the energy calibration curve (polynomial) is used. A priori information about the relationships among the energies of different peaks on the spectrum is taking into account by a Monte Carlo simulation. The procedure was used in obtaining of {B_n} for {{^118}Sn} and {{^64}Cu}. The {gamma}-ray spectrum from thermal neutron radiative capture by {{^117}Sn} has been measured on the IBR-2 pulsed reactor. {gamma}-rays were detected by a 72 cm^3 HPGe-detector. {B_n} for {{^64}Cu} was obtained from two {gamma}-...

  6. Atmospheric deposition of rare earth elements in Albania studied by the moss biomonitoring technique, neutron activation analysis and GIS technology.

    Science.gov (United States)

    Allajbeu, Sh; Yushin, N S; Qarri, F; Duliu, O G; Lazo, P; Frontasyeva, M V

    2016-07-01

    Rare earth elements (REEs) are typically conservative elements that are scarcely derived from anthropogenic sources. The mobilization of REEs in the environment requires the monitoring of these elements in environmental matrices, in which they are present at trace level. The determination of 11 REEs in carpet-forming moss species (Hypnum cupressiforme) collected from 44 sampling sites over the whole territory of the country were done by using epithermal neutron activation analysis (ENAA) at IBR-2 fast pulsed reactor in Dubna. This paper is focused on REEs (lanthanides) and Sc. Fe as typical consistent element and Th that appeared good correlations between the elements of lanthanides are included in this paper. Th, Sc, and REEs were never previously determined in the air deposition of Albania. Descriptive statistics were used for data treatment using MINITAB 17 software package. The median values of the elements under investigation were compared with those of the neighboring countries such as Bulgaria, Macedonia, Romania, and Serbia, as well as Norway which is selected as a clean area. Geographical distribution maps of the elements over the sampled territory were constructed using geographic information system (GIS) technology. Geochemical behavior of REEs in moss samples has been studied by using the ternary diagram of Sc-La-Th, Spider diagrams and multivariate analysis. It was revealed that the accumulation of REEs in current mosses is associated with the wind-blowing metal-enriched soils that is pointed out as the main emitting factor of the elements under investigation.

  7. Modernization and reconstruction of ageing Russian research reactors as the method to extend their operational life

    International Nuclear Information System (INIS)

    Khmelshchikov, V.V.; Tretjakov, I.T.; Portnov, A.A.; Vinogradov, A.V.

    2000-01-01

    The common situation in Russian atomic industry exhibits a tendency to steady aging of research reactor (RR) facilities and extremely limited financial means for constructing new equipment instead of old. Modernization and reconstruction of operating RR after their designed resources exhausted are the most optimum strategic prospects in nearest 10 years. With respect to modernization strategy the following positive factors are of great importance: (a) additional lands are not occupied for construction site; (b) the exploitation of reactor building and a considerable part of technological system equipment is in progress. Their operational life is longer than of in-reactor devices (subjected to irradiation and heating) as a rule, and lasts no less than 50-60 years; (c) experimental base, which may be improved to carry out new tasks, is retained; (d) skilled personnel is preserved, since it can be employed in resembling works during the reactor shutdown; (e) the main strategic object is to retain research and experimental base with minimum financial and temporal expenses. Two Russian RR IRT and IBR-2 can cite an example of general and concrete approach to the issues including safety enhancement and development of the reactor engineering with reconstruction and modernization of aging facilities. (author)

  8. The influence of neutron radiation damage on the optical properties of plastic scintillator UPS 923A

    Science.gov (United States)

    Mthembu, Skhathisomusa; Davydov, Yuri; Baranov, Vladimir; Mellado Garcia, Bruce; Mdhluli, Joyful; Sideras-Haddad, Elias

    2017-09-01

    Plastic scintillators are vital in the reconstruction of hadronic particle energy and tracks resulting from the collision of high energy particles in the Large Hadron Collider (LHC) at CERN. These plastic scintillators are exposed to harsh radiation environments and are susceptible to radiation damage. The effects of radiation damage on the transmittance, luminescence and light yield of Ukraine polystyrene-based scintillator UPS 923A were studied. Samples were irradiated with fast neutrons, of varying energies and fluences, using the IBR-2 reactor FLNP (Frank Laboratory for Nuclear Problems) at the Joint Institute for Nuclear Research. Results show a small change in the transmittance of the higher energy visible spectrum, and a noticeable change in the light yield of the samples as a result of the damage. There is no change observed on the luminescence as a result of radiation damage at studied fluences. The doses and uences of the neutrons shall be increased and changes in optical properties as a result of the radiation shall be further studied.

  9. Preparation of FMD type A87/IRN inactivated vaccine by gamma irradiation and the immune response on guinea pig

    International Nuclear Information System (INIS)

    Sedeh, Farahnaz Motamedi; Shafaee, Kamal; Fatolahi, Hadi; Arbabi, Kourosh; Khorasani, Akbar

    2008-01-01

    FMD is one of the most economically damaging diseases that affect livestock animals. In this study FMD Virus type A87/IRN was multiplied on BHK21 cells. The virus was titrated by TCID50 method, it was 10 7.5 /ml. The FMD virus samples were inactivated by gamma ray from 60 Co source at -20 deg C. Safety test was done by IBRS2 monolayer cell culture method, also antigenicity of irradiated and un-irradiated virus samples were studied by Complement Fixation Test. The dose/survival curve for irradiated FMD Virus was drawn, the optimum dose range for inactivation of FMDV type A87/IRN and unaltered antigenicity was obtained 40-44 kGy. The inactivated virus samples by irradiation and ethyleneimine (EI) were formulated respectively as vaccine with Al(OH) 3 gel and other substances. The vaccines were inoculated to Guinea pigs and the results of Serum Neutralization Test for the normal vaccine and radio-vaccine showed protective titer after 8 months. The potency test of the inactivated vaccines was done, PD50 Value of the vaccines were calculated 7.06 and 5.6 for inactivated vaccine by EI and gamma irradiation respectively. (author)

  10. FMD virus type Asia-1 irradiated vaccine and evaluation of immune response on guinea-pig model

    Directory of Open Access Journals (Sweden)

    Farahnaz Motamedi-Sedeh

    2017-09-01

    Full Text Available Introduction: Foot and Mouth Disease (FMD is the most contagious disease in cloven-hoofed animals which causes a lot of economical losses. FMD virus belongs to Picornaviridae family and Aphthovirus genus. The aim of the study is evaluation of humoral and cellular immune responses triggered by a Gamma-irradiated FMD vaccine in the guinea-pig model. Materials and Methods: FMD virus type Asia-1 was multiplied on BHK21 cell line and irradiated by gamma ray in different doses. According  to dose/survival curve, D10 value and optimum dose of virus inactivation were calculated 7.69 and 50 kGy, respectively. Antigenic characteristic of irradiated and un-irradiated virus samples were evaluated by complement fixation test (CF test and safety test was done by four blind passages cell culture on IBRS2 cell line. The inactivated virus sample was formulated as Radio- vaccine and immune responses were evaluated in three groups of ginea-pigs; the first group Radio-vaccine, the second group conventional vaccine and the last one was negative control. Results: The results of neutralizing antibody titration for two vaccinated groups were significant (P

  11. Aggregation study in mixture surfactant system TX-100+SDS in heavy water solutions by SANS method

    Science.gov (United States)

    Rajewska, A.; Islamov, A. Kh.; Bakeeva, R. F.

    2018-03-01

    The mixing of amphiphiles in water may lead to the formation of mixed micelles which often present new properties with respect to the pure component solutions [1,2]. The mixture system of classic surfactants SDS (sodium dodecyl sulfate)+TX-100(p-(1,1,3,3- tetramethyl) poly(oxyethylene) (anionic + non-ionic) in heavy water solutions was investigated at temperatures 30°, 50°, 70°C for compositions 1:1, 2:1, 3:1 by the small-angle neutron scattering(SANS) method on spectrometer (‘YuMO’) at the IBR-2 pulsed neutron source at FLNP, JINR in Dubna (Russia). Measurements have covered Q range from 8x10-3 to 0.4 Å-1. From the measured dependence of the scattered intensity on the scattering angle, we derived the size, shape of micelles, aggregation number at various compositions and temperatures. The size of mixed micelle is a weak function of the mixing ratio between the two components.

  12. Determination of the structure factor of interparticle interactions in the ferrofluid by small-angle neutron scattering

    Directory of Open Access Journals (Sweden)

    A. V. Nagornyi

    2014-03-01

    Full Text Available Results of the structure and interparticle interaction investigations of polar magnetic fluid with different con-tent of magnetite, which are obtained by small-angle neutron scattering (SANS are presented in the work. The experiment was performed on small-angle scattering spectrometer YuMO at the Pulsed Reactor IBR-2 in the Joint Institute for Nuclear Research (Dubna, Russia. Polar ferrofluid magnetite/oleic and dodecyl-benzenesulfonic acid/isobutanol was considered. It is shown that the experimental SANS curves are well described by form-factor for polydisperse spherical particles only for ferrofluids with magnetite concentration of about 0.5 vol. %. Signifi-cant effect of structural factors on the SANS spectra was observed for respectively large concentrations of mag-netic material in the volume of ferrofluid. Aggregation of magnetic particles and the molecules of the stabilizer do not occur in the considered concentration range of magnetic material. Experimentally obtained dependences of the effective structure factor as well as the comparison with the theoretical curve calculated for the hard sphere potential in polydisperse approximation are presented in the work.

  13. SANS method study of surfactant mixture system TX-100+C16TAB in heavy water solutions

    Science.gov (United States)

    Rajewska, A.; Islamov, A. Kh; Bakeeva, R. F.

    2017-05-01

    The mixture system of two classic surfactants cationic and non-ionic - C16TAB (hexadecyltrimethylammonium bromide)+TX-100(p-(1,1,3,3-tetramethyl) poly(oxyethylene) in heavy water solutions was investigated at temperatures 30o, 50o, 70o for compositions 1:1, 2:1, 3:1 by the small-angle neutron scattering(SANS) method on spectrometer (‘YuMO’) at the IBR-2 pulsed neutron source at FLNP, JINR in Dubna (Russia). Measurements have covered Q range from 7x10-3 to 0.4 Å-1. The SANS measurements of aqueous solutions of nonionic / cationic surfactants have shown that the mixed micelles are formed [1-2]. From the measured dependence of the scattered intensity on the scattering angle, we derived the size, shape of micelles, aggregation number at various compositions and temperatures. The size of mixed micelle is a weak function of the mixing ratio between the two components.

  14. Ways of providing radiation resistance of magnetic field semiconductor sensors

    CERN Document Server

    Bolshakova, I A; Holyaka, R; Matkovskii, A; Moroz, A

    2001-01-01

    Hall magnetic field sensors resistant to hard ionizing irradiation are being developed for operation under the radiation conditions of space and in charged particle accelerators. Radiation resistance of the sensors is first determined by the properties of semiconductor materials of sensitive elements; we have used microcrystals and thin layers of III-V semiconductors. Applying complex doping by rare-earth elements and isovalent impurities in certain proportions, we have obtained magnetic field sensors resistant to irradiation by fast neutrons and gamma-quanta. Tests of their radiation resistance were carried out at IBR-2 at the Joint Institute for Nuclear Research (Dubna). When exposed to neutrons with E=0.1-13 MeV and intensity of 10 sup 1 sup 0 n cm sup - sup 2 s sup - sup 1 , the main parameter of the sensors - their sensitivity to magnetic fields - changes by no more than 0.1% up to fluences of 10 sup 1 sup 4 n cm sup - sup 2. Further improvement of radiation resistance of sensor materials is expected by ...

  15. Anisotropic mobility and carrier dynamics in the β-type BEDT-TTF salts as studied by inter-layer transverse magnetoresistance

    Directory of Open Access Journals (Sweden)

    Shigeharu Sugawara and Masafumi Tamura

    2013-01-01

    Full Text Available A new method to estimate an in-plane conduction anisotropy in a quasi-two-dimensional (q2D layered conductor by measuring the inter-layer transverse magnetoresistance is proposed. We applied this method to layered organic conductors β-(BEDT-TTF2X (BEDT-TTF = bis(ethylenedithiotetrathiafulvalene, C10H8S8; X = IBr2, I2Br by applying magnetic field rotating within the basal plane at 4.2 K. We found the anisotropic behaviour of carrier mobility μ. From this, anomalous distribution of carrier lifetime τ on the Fermi surface is derived, by the use of Fermi surface data reported for the materials. Calculations of the non-uniform susceptibility χ0(q suggest that carrier scattering is enhanced at specific k-points related to partial nesting of the Fermi surface. The present method is thus demonstrated to be an efficient experimental tool to elucidate anisotropic carrier dynamics in q2D conductors.

  16. Application Of NAA And AAS In Environmental Research In Slovakia

    International Nuclear Information System (INIS)

    Florek, M.; Holy, K.; Meresova, J.; Sykora, I.; Frontasveva, M. V.; Ermakova, E.E.; Pavlov, S.S.; Mankovska, B.

    2007-01-01

    The concentrations of 41 chemical elements (heavy metals, rare earths, and actinides) were determined in atmospheric aerosol using nuclear and related analytical techniques. The sampling location was in Bratislava (Slovak Republic). The main goal of this study is the quantification of the atmospheric pollution and its trend. The elemental content in filters was measured using instrumental neutron activation analysis (NAA) at IBR-2 reactor in JINR Dubna and by atomic absorption spectrometry (AAS) in Bratislava. The obtained results confirm the decreasing trend of pollution by most of the heavy metals in Bratislava atmosphere, and they are compared with the contents of pollutants in atmosphere of other cities, including Cairo. We determined also the composition of clear filter materials. Results on atmospheric deposition of heavy metals and other trace elements in the whole territory Slovakia using the moss bio monitoring technique are presented, too. The level of the elements found in the bryophytes reflects the relative atmospheric deposition loads of the elements at the investigated sites. Factor analysis was applied to determine possible sources of trace element deposition in the Slovakian moss. The marginal hot spots were revealed near nonferrous ores processing and factories and dumps of stone chips. The trans-boundary contamination by Hg through dry and wet deposition from Czech Republic and Polish is evident in the bordering territory in the north-west part of Slovakia (The Small Black Triangle), known for metallurgical works, coal processing and chemical industries

  17. Neutron induced radiation damage of plastic scintillators for the upgrade of the Tile Calorimeter of the ATLAS detector.

    Science.gov (United States)

    Mdhluli, J. E.; Jivan, H.; Erasmus, R.; Davydov, Yu I.; Baranov, V.; Mthembu, S.; Mellado, B.; Sideras-Haddad, E.; Solovyanov, O.; Sandrock, C.; Peter, G.; Tlou, S.; Khanye, N.; Tjale, B.

    2017-07-01

    With the prediction that the plastic scintillators in the gap region of the Tile Calorimeter will sustain a significantly large amount of radiation damage during the HL-LHC run time, the current plastic scintillators will need to be replaced during the phase 2 upgrade in 2018. The scintillators in the gap region were exposed to a radiation environment of up to 10 kGy/year during the first run of data taking and with the luminosity being increased by a factor of 10, the radiation environment will be extremely harsh. We report on the radiation damage to the optical properties of plastic scintillators following irradiation using a neutron beam of the IBR-2 pulsed reactor in Joint Institute for Nuclear Research (JINR), Dubna. A comparison is drawn between polyvinyl toluene based commercial scintillators EJ200, EJ208 and EJ260 as well as polystyrene based scintillator from Kharkov. The samples were subjected to irradiation with high energy neutrons and a flux density range of 1 × 106-7.7 × 106. Light transmission, Raman spectroscopy, fluorescence spectroscopy and light yield testing was performed to characterize the damage induced in the samples. Preliminary results from the tests done indicate a minute change in the optical properties of the scintillators with further studies underway to gain a better understanding of the interaction between neutrons with plastic scintillators.

  18. Time-resolved neutron diffraction investigation of effect of hydrogen on the high-Tc superconductor YBa2Cu3O7-δ

    International Nuclear Information System (INIS)

    Balagurov, A.M.; Galkin, V.Yu.; Rudnickij, L.A.

    1990-01-01

    The results of time-resolved neutron diffraction investigation of the interaction of hydrogen flow with the high-T c superconductor YBa 2 Cu 3 O 7-δ are presented. The experiment was carried out on the TOF diffractometer DN-2 at the reactor IBR-2 in Dubna. Hydrogenation was performed on small pieces of 1-2-3 ceramics which were enclosed inside a quartz tube. The sample was heated up to 350 C with a constant rate of 5 deg./min. Diffraction patterns were collected every 3 min within the d nkl -interval of 1-20 A. Up to 220 C the refinement yielded the well known orthorhombic phase of the 1-2-3 structure without any remarkable reduction of the (b-a)/(a+b) ratio. Below this temperature the only change in the specimen was a gradual increase of the incoherent background which occurred even at room temperature. Once the temperature 220 C was reached the sample degradation took place as evidenced by precipitation of metallic copper, drastic increase of background and widening of diffraction peaks. Simultaneously, the occupancy of 04+05 sites fell down to 0.6 No evidence was found for the formation of solid solution of hydrogen in 1-2-3 structure. 9 refs.; 6 figs

  19. Study of α-crystallin structure by small-angle neutron scattering with contrast variation

    International Nuclear Information System (INIS)

    Krivandin, A.V.; Muranov, K.O.; Polyanskij, N.B.; Ostrovskij, M.A.; Murugova, T.N.; Kuklin, A.I.; Aksenov, V.L.

    2010-01-01

    The structure of the oligomeric protein α-crystallin from the bovine eye lens has been investigated by small-angle neutron scattering (SANS) by the contrast variation method (volume fraction of D 2 O was 0, 23, 68 and 90%). Experiments were carried out on YuMO spectrometer (IBR-2 reactor, JINR). From the SANS curves the match point for α-crystallin (43% D 2 O) and its average scattering length density at this point (2.4·10 10 cm -2 ) have been obtained. The radius of gyration and distance distribution functions for α-crystallin have been calculated as well. On the basis of these calculations it was concluded that α-crystallin has a homogeneous distribution of the scattering density in domains inaccessible for water penetration and all parts of this protein undergo a uniform deuteration. The latter indicates that all α-crystallin subunits have an equal accessibility for water and presumably for some other low molecular weight substances. These conclusions on the α-crystallin structure (a homogeneous distribution of the scattering density and an equal accessibility of all subunits for low molecular weight substances) should be taken into account in the time of elaboration of α-crystallin quaternary structure models

  20. Heavy Metals and Trace Elements Atmospheric Deposition Studies in Tula Region Using Moss Biomonitors Technique

    CERN Document Server

    Ermakova, E V; Steinnes, E

    2002-01-01

    For the first time the moss biomonitors technique was used in air pollution studies in Tula Region (Central Russia), applying NAA, AAS. Moss samples were collected at 83 sites in accordance with the sampling strategy adopted in European projects on biomonitoring atmospheric deposition. A wide set of trace elements in mosses was determined. The method of epithermal neutron activation at IBR-2 reactor of FLNP JINR has made it possible to identify 33 elements (Na, Mg, Al, Cl, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Zn, As, Br, Rb, Sr, Mo, Sb, I, Cs, Ba, La, Ce, Sm, Tb, Yb, Hf, Ta, W, Th, U) in the large-scale concentration range - from 10000 ppm for K to 0,001 ppm for Tb and Ta. Cu, Cd and Pb were determined by the flame AAS in the Norwegian Institute of Science and Technology. Using the graphical technique and principal component analysis allowed to separate plant, crustal and general pollution components in the moss. The obtained data will be used for constructing coloured maps of the distribution of elements over t...

  1. New Results from Air Pollution Studies in Romania

    CERN Document Server

    Stan, O A; Frontasyeva, M V; Steinnes, E

    2000-01-01

    Results from the next stage of the project "Atmospheric Deposition of Heavy Metals in Rural and Urban Areas of Romania Studied by the Moss Biomonitoring Technique Employing Nuclear and Related Analytical Techniques", carried out under the auspieces of the International Atomic Energy Agency, Vienna, are reported. A total of 70 moss samples (Hypnum Cupressiforme) were collected from highly polluted areas in the north-eastern part of Transylvania during the summer of 1999. The samples were analyzed by epithermal neutron activation analysis at the pulsed fast reactor IBR-2 at JINR, Dubna, for a wide range of elements including heavy metals and rare earths (Na, Mg, Al, Cl, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni ((n,p) reaction), Cu, Zn, As, Se, Br, Rb, Sr, Zr, Mo, Ag, Sn, Sb, I, Cs, Ba, La, Ce, Nb, Sm, Eu, Gd, Tb, Hf, Ta, W, Au, Th, and U). IAEA certified reference materials were used to ensure the quality of the measurements. The regional extent of pollution patterns of specific metals was determined. Like another stro...

  2. Air Pollution Studies in Central Russia (Tula Region) Using Moss Biomonitoring Technique, NAA and AAS

    CERN Document Server

    Ermakova, E V; Steinnes, E

    2002-01-01

    For the first time the moss biomonitoring technique has been applied to air pollution monitoring in Central Russia (Tula Region). Moss samples were collected from 83 sites in accordance with the sampling strategy of European projects on biomonitoring of atmospheric deposition. Neutron activation analysis (NAA) at the IBR-2 reactor has made it possible to determine the concentration of 33 elements (Na, Mg, Al, Cl, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Zn, As, Br, Rb, Sr, Mo, Sb, I, Cs, Ba, La, Ce, Sm, Tb, Yb, Hf, Ta, W, Th, U) over a large concentration range (from 10000 mg/kg for K to 0.001 mg/kg for Tb and Ta). In addition to NAA, flame AAS (atomic absorption spectrometry) was applied to determine the concentration of Cd, Cu and Pb. Factor analysis was applied to determine possible sources of elements detected in the investigated mosses. Eight factors were identified. The geographical distribution of factor scores is presented. The interpretation of the factor analysis findings points to natural as well as anthr...

  3. Testing an ionization chamber with gaseous samples and measurements of the (n, alpha) reaction cross sections

    CERN Document Server

    Gledenov, Yu M; Salatskii, V I; Sedyshev, P V; Andrzejewski, J; Szalanski, P

    1999-01-01

    A new ionization chamber with gaseous samples (GIC) has been designed and tested on the thermal and resonance neutron beams of FLNP's neutron sources. The exposed gas volume serves as a target for neutrons. The obtained thermal cross sections for the sup 1 sup 7 O(n, alpha) sup 1 sup 4 C, sup 2 sup 1 Ne(n, alpha) sup 1 sup 8 O and sup 3 sup 6 Ar(n, alpha) sup 3 sup 3 S reactions are (233+-12) mb, (0.18+-0.09) mb and (5.43+-0.27) mb, respectively. These measurements have been performed on a pure beam of thermal neutrons from the high flux reactor IBR-2; and they demonstrated high efficiency and reliability of the method. Compared to samples on substrates, the application of gaseous samples makes the beam background essentially lower, and what is more important, the background component is totally absent due to the absence of Li and B microimpurities in gaseous samples while they do present in the samples on substrates. The method is also applicable to measurements with resonance neutrons. The recovery capabili...

  4. Active moss biomonitoring applied to an industrial area in Romania: variation of element contents with the height of exposure site

    International Nuclear Information System (INIS)

    Culicov, O.; Yurukova, L.; Mocanu, R.; Frontasyeva, V.; Sarbu, C.

    2007-01-01

    Neutron activation analysis and the moss-bag transplant technique were used to investigate the variation of element contents with the height of the exposure site of Sphagnum girgensohnii samples in the strongly polluted town of Baia Mare, Romania, according to a novel sampling design. Moss collected from the background area in Moscow region, Russia, was hanged in bags at 3 locations spread within an area of one square kilometre, and analyzed after 4 months of exposure. At each location a number of 15 samples were suspended at 6 different levels above the ground: 6, 12, 18, 24 and 30 m. A total of 35 elements were determined by NAA at IBR-2 reactor in Dubna, Russia. Discriminant Analysis allowed depicting the differences between the accumulation patterns of moss at different levels of exposure and at various locations. The concentration of only twenty four and twenty five elements of thirty five provided sufficient information to enable classification rules to be developed for identifying moss samples according with their height of exposure and location, respectively. The most discriminant elements have the F values (indicating the statistical significance in the discrimination between groups) descending in the following order: K, Rb, Sb, Cs, Zn, Cl for the location model and Ca, Cd, As, Sr, Ba, Cl for the height model. A good agreement have been observed between the groups obtained by applying Discriminant Analysis and the origin of the samples. A small number of elements are significant for the separation of moss-bags by height in individual locations. The parameter ?variation in concentration by height? is less significant than the parameter ? variation in concentration by location?

  5. Life sciences research at JINR, Dubna, Russia

    International Nuclear Information System (INIS)

    Frontasyeva, M.V.

    2007-01-01

    Within the broad spectrum of activities in the Life Sciences at JINR such as nuclear medicine and pharmacy, radiation biology, radioecology, radioisotope production radioanalytical investigations play a special role due to the long-term experience in multi-element instrumental neutron activation analysis (INAA) at the reactor IBR-2 of FLNP, JINR. INAA is presently being used in several projects on air pollution studies using bio monitors (moss, lichens, tree bark). The results for some selected areas of Central Russia, South Urals, and countries of Europe (Bulgaria, Poland, Romania, Bosnia and Herzegovina, Serbia and Montenegro, Macedonia, Slovakia, Western Ukraine) are reported to the European Atlas of Heavy Metal Atmospheric Deposition edited under the auspices of the Environmental Commission of the United Nations. Battering-ram studies using NAA were initiated also in Turkey, China and South Korea. Applied to the analysis of air filters, INAA is successfully used in assessing quality of London underground air, Sahara desert impact on the Greater Cairo Area. Epithermal activation analysis in combination with atomic absorption spectrometry and energy-disperse X-ray fluorescence allowed source evaluation of metals in soil from some industrial and metropolitan areas of Russia (South Urals, Cola Peninsula) and the USA (Minneapolis). The analytical possibilities of NAA are favorably used in biotechnology, (i) for investigation of bacterial leaching of metals, including uranium and thorium from low-grade ores, rocks and industrial wastes; (i i) in the development of new pharmaceuticals based on the blue-green alga Spirulina platensis. Occupational health studies are carried out at several fertilizer plants in Russia, Uzbekistan, Poland, Romania, Denmark and the Netherlands in the framework of the 5th Programme Copernicus. The quality of foodstuffs grown in some contaminated areas of Russia is investigated in the framework of IAEA Coordinated Research Programme. In

  6. Small-Angle Neutron Scattering investigations of ferrofluids with different carrier liquids

    International Nuclear Information System (INIS)

    Balasoiu, M.; Avdeev, M. V.; Hasegan, D.; Ghenescu, V.; Ghenescu, M.; Bica, D.; Vekas, L.

    2004-01-01

    The aim of this paper is to present a method to investigate the properties of magnetic fluids by means of small angle neutron scattering (SANS). Ferrofluids are dispersions of small, single-domain magnetic particles suspended in a fluid carrier. The neutron scattering methods have been largely used the last two decades for the determination of structural properties of magnetic liquids at microscopic level. There can be investigated the structure of the particle, the aggregation phenomena, the magnetic liquid dynamics, particle-surfactant interaction, surfactant liquid-base interaction and structure and magnetic behavior of the samples. SANS is often used in structural studies of ferrofluids exploring two specific features of neutrons, the possibility of wide contrast variation using protonated/deuterated components and high magnetic scattering from ferromagnetics. This method can be effectively used for determination of the structural parameters of ferrofluids at the scale interval of 1-100 nm. In previous SANS experiments with ferrofluids of the same type it was shown that the nuclear scattering is described well by the spherical core-shell model (magnetite core plus surfactant shell) in a wide interval of momentum transfer (0.05 - 5 nm -1 ) and no significant effects of aggregation and interparticle interaction were observed in this interval for the magnetite concentration up to 5 vol. %. Experiments on small angle neutron scattering were carried out on SANS instrument YuMO in function at IBR-2 high pulsed reactor at the Frank Laboratory of Neutron Physics, Joint Institute of Nuclear Research, Dubna, Russia. (authors)

  7. Neutron, gamma and Roentgen fluorescent activation analysis of hair of children suffering from bronchial asthma

    Energy Technology Data Exchange (ETDEWEB)

    Alekseeva, O.A.; Belov, A.G.; Frontasyeva, M.V.; Gundorina, S.F.; Gustova, M.V.; Kusmenko, L.G.; Perelygin, V.P. E-mail: pergam@cv.jinr.ru; Zaverioukha, O.S

    2001-06-01

    The aim of present study was the multiparametric study of dangerous microelements content in the hair of children under school and primary school age which included 12 children ill with bronchial asthma and 11 control group persons in the town of Troitsk, Moscow Region. The hair specimens with weight 15-220 mg were analysed with the application of epithermal neutron activation analysis conducted at experimental installation REGATA and neutron source-unique Pulsed Fast Reactor IBR-2, with the application of combined gamma-neutron irradiation at Microtron MT-25 and with Roentgen Fluorescence Analysis device of JINR. The data of elements content in hair were obtained with solid state track detectors and semiconductor electronic spectrometers. The solid state track detectors provide the determination of U, Th, Bi and Be elements at the level of sensitivity up to 10{sup -8}-10{sup -9} g/g. These data were compared with more representative information about dangerous microelements concentration obtained with NAA and RFA analyses. The obtained concentrations of most elements vary in a wide range, but in agreement with the known data. The highest degree of element dispersion was observed for U, Th, Pb, I, Br, Sb, Co, K and Be (the radiation coefficient was higher than 100-200%). The presented analysis of results shows that in the clinical picture there is some proved correlation between an increased content of some element in hair and symptoms of their accumulation in the organism of ill children, the revelation of which is the basic idea of our examination.

  8. Epithermal Neutron Activation Analysis of the Asian Herbal Plants

    Science.gov (United States)

    Baljinnyam, N.; Jugder, B.; Norov, N.; Frontasyeva, M. V.; Ostrovnaya, T. M.; Pavlov, S. S.

    2011-06-01

    Asian medicinal herbs Chrysanthemum (Spiraea aquilegifolia Pall.) and Red Sandalwood (Pterocarpus Santalinus) are widely used in folk and Ayurvedic medicine for healing and preventing some diseases. The modern medical science has proved that the Chrysanthemum (Spiraea aquilegifolia Pall.) possesses the following functions: reducing blood press, dispelling cancer cell, coronary artery's expanding and bacteriostating and Red Sandalwood (Pterocarpus Santalinus) is recommended against headache, toothache, skin diseases, vomiting and sometimes it is taken for treatment of diabetes. Species of Chrysanthemums were collected in the north-eastern and central Mongolia, and the Red Sandalwood powder was imported from India. Samples of Chrysanthemums (branches, flowers and leaves) (0.5 g) and red sandalwood powder (0.5 g) were subjected to the multi-element instrumental neutron activation analysis using epithermal neutrons (ENAA) at the IBR-2 reactor, Frank Laboratory of Neutron Physics (FLNP) JINR, Dubna. A total of 41 elements (Na, Mg, Al, Cl, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Br, Rb, Sr, Zr, Mo, Cd, Cs, Ba, La, Hf, Ta, W, Sb, Au, Hg, Ce, Nd, Sm, Eu, Tb, Dy, Yb, Th, U, Lu) were determined. For the first time such a large group of elements was determined in the herbal plants used in Mongolia. The quality control of the analytical results was provided by using certified reference material Bowen Cabbage. The results obtained are compared to the "Reference plant» data (B. Markert, 1992) and interpreted in terms of excess of such elements as Se, Cr, Ca, Fe, Ni, Mo, and rare earth elements.

  9. Epithermal Neutron Activation Analysis of the Asian Herbal Plants

    International Nuclear Information System (INIS)

    Baljinnyam, N.; Frontasyeva, M. V.; Ostrovnaya, T. M.; Pavlov, S. S.; Jugder, B.; Norov, N.

    2011-01-01

    Asian medicinal herbs Chrysanthemum (Spiraea aquilegifolia Pall.) and Red Sandalwood (Pterocarpus Santalinus) are widely used in folk and Ayurvedic medicine for healing and preventing some diseases. The modern medical science has proved that the Chrysanthemum (Spiraea aquilegifolia Pall.) possesses the following functions: reducing blood press, dispelling cancer cell, coronary artery's expanding and bacteriostating and Red Sandalwood (Pterocarpus Santalinus) is recommended against headache, toothache, skin diseases, vomiting and sometimes it is taken for treatment of diabetes. Species of Chrysanthemums were collected in the north-eastern and central Mongolia, and the Red Sandalwood powder was imported from India. Samples of Chrysanthemums (branches, flowers and leaves)(0.5 g) and red sandalwood powder (0.5 g) were subjected to the multi-element instrumental neutron activation analysis using epithermal neutrons (ENAA) at the IBR-2 reactor, Frank Laboratory of Neutron Physics (FLNP) JINR, Dubna. A total of 41 elements (Na, Mg, Al, Cl, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Br, Rb, Sr, Zr, Mo, Cd, Cs, Ba, La, Hf, Ta, W, Sb, Au, Hg, Ce, Nd, Sm, Eu, Tb, Dy, Yb, Th, U, Lu) were determined. For the first time such a large group of elements was determined in the herbal plants used in Mongolia. The quality control of the analytical results was provided by using certified reference material Bowen Cabbage. The results obtained are compared to the ''Reference plant? data (B. Markert, 1992) and interpreted in terms of excess of such elements as Se, Cr, Ca, Fe, Ni, Mo, and rare earth elements.

  10. Biomonitoring air pollution in Chelyabinsk region (Ural mountains, Russia) through trace-elements and radionuclides: Temporal and spatial trends

    International Nuclear Information System (INIS)

    Cherchintsev, V.D.; Frontasyeva, M.V.; Lyapunov, S.M.; Smirnov, L.I.

    1999-01-01

    This report contains the first results on the analysis of the moss species Hylocomium splendens and Pleurozium schreberi which were used to study heavy metal atmospheric deposition in the vicinity of Magnitogorsk, the center of the iron steel industry of Russia. Moss samples were collected along Bannoe Lake, located 30 km north-west of Magnitogorsk, and were analyzed by instrumental neutron activation analysis using epithernal neutrons (ENAA) at the IBR-2 pulsed fast reactor in Dubna, and by atomic absorption spectroscopy (AAS) at the Geological Institute of RAS, Moscow. Results for a total of 38 elements were obtained, including Pb, Cd, and Cu determined by AAS. The element concentrations in moss samples from this area were compared with those available for the so-called 'Black Triangle' (the territory bordering Poland, Czechia and Slovakia), obtained by the same moss biomonitoring technique. The level of the concentrations of Fe, Cr, and V in the vicinity of Magnitogorsk was found to be 2-2.5 times higher than that of the mean values determined for the 'Black Triangle'; the level of Ni and Cd is of the same order as in the most polluted area of Europe. The concentrations of Zn and Cu tend to be higher in the 'Black Triangle'. The level of As is about 3 times higher in the Urals, whereas concentration of Pb is higher in Europe by a factor of 5. It appeared that concentration of Sb in the examined area has the highest ever published for levels in mosses from atmospheric deposition. The scanning electron microscope adjacent to the XRF analyzer (SEM-XRF) was used to examine the surface of the moss samples. Photographs of identified iron spherulas along with other aerosol particles were made at magnification of 3,500 to 5,000 times. Information on fieldwork in the northern part of the Chelyabinsk region in July, 1998 is reported. (author)

  11. Neutron, gamma and Roentgen fluorescent activation analysis of hair of children suffering from bronchial asthma

    International Nuclear Information System (INIS)

    Alekseeva, O.A.; Belov, A.G.; Frontasyeva, M.V.; Gundorina, S.F.; Gustova, M.V.; Kusmenko, L.G.; Perelygin, V.P.; Zaverioukha, O.S.

    2001-01-01

    The aim of present study was the multiparametric study of dangerous microelements content in the hair of children under school and primary school age which included 12 children ill with bronchial asthma and 11 control group persons in the town of Troitsk, Moscow Region. The hair specimens with weight 15-220 mg were analysed with the application of epithermal neutron activation analysis conducted at experimental installation REGATA and neutron source-unique Pulsed Fast Reactor IBR-2, with the application of combined gamma-neutron irradiation at Microtron MT-25 and with Roentgen Fluorescence Analysis device of JINR. The data of elements content in hair were obtained with solid state track detectors and semiconductor electronic spectrometers. The solid state track detectors provide the determination of U, Th, Bi and Be elements at the level of sensitivity up to 10 -8 -10 -9 g/g. These data were compared with more representative information about dangerous microelements concentration obtained with NAA and RFA analyses. The obtained concentrations of most elements vary in a wide range, but in agreement with the known data. The highest degree of element dispersion was observed for U, Th, Pb, I, Br, Sb, Co, K and Be (the radiation coefficient was higher than 100-200%). The presented analysis of results shows that in the clinical picture there is some proved correlation between an increased content of some element in hair and symptoms of their accumulation in the organism of ill children, the revelation of which is the basic idea of our examination

  12. Selected Abstracts of the 2nd Congress of joint European Neonatal Societies (jENS 2017; Venice (Italy; October 31-November 4, 2017; Session "Neonatal Hematology and Bilirubin"

    Directory of Open Access Journals (Sweden)

    --- Various Authors

    2017-10-01

    Full Text Available Selected Abstracts of the 2nd Congress of joint European Neonatal Societies (jENS 2017; Venice (Italy; October 31-November 4, 201758th ESPR Annual Meeting, 7th International Congress of UENPS, 3rd International Congress of EFCNIORGANIZING INSTITUTIONSEuropean Society for Paediatric Research (ESPR, European Society for Neonatology (ESN, Union of European Neonatal & Perinatal Societies (UENPS, European Foundation for the Care of Newborn Infants (EFCNIORGANIZING COMMITTEELuc Zimmermann (President of ESPR, Morten Breindahl (President of ESN, Manuel Sánchez Luna (President of UENPS, Silke Mader (Chairwoman of the Executive Board and Co-Founder of EFCNISCIENTIFIC COMMITTEEVirgilio P. Carnielli (Congress President Chair, Pierre Gressens (Past Scientific President, Umberto Simeoni, Manon Benders, Neil Marlow, Ola D. Saugstad, Petra Hüppi, Agnes van den HoogenSession "Neonatal Hematology and Bilirubin"ABS 1. PROLONGED JAUNDICE SCREENING: FULL BLOOD COUNT (FBC OR NO FBC! • N. Storring, R. Doherty, V. PonnusamyABS 2. EFFECT OF PROBIOTIC SUPPLEMENTATION ON BREAST MILK JAUNDICE • N. Koksal, O. Bagcı, H. Ozkan, I. Varal, P. DoganABS 3. LABORATORY FINDINGS, DIAGNOSIS AND TREATMENT OF THE NEWBORN ADMITTED DUE TO HEMATEMESIS OR BLOODY STOOL IN 11 YEARS • I. Hokuto, Y. Ito, T. Mori, S. KomachiABS 4. AN UNUSUAL CAUSE OF CYANOSIS: SEVERE METHEMOGLOBINEMIA IN A PRETERM INFANT WITH SEPSIS • F. Bakar, M. BerberABS 5. THE INFLUENCE OF INTRAUTERINE TRANSFUSION ON THE OUTCOMES OF NEWBORNS WITH SEVERE HEMOLYTIC DISEASE • E. Balashova, O. Bystrykh, T. Fedorova, O. Ionov, A. Kirtbaya, D. Sharafutdinova, V. Zubkov, D. Degtyarev, O. Horoshkeeva, N. Fedorova, N. Tetruashvili, K. Kostukov, N. KaretnikovaABS 6. PATCHED SKIN BILIRUBIN ASSAY TO MONITOR EXTREMELY PRETERM NEONATES UNDERGOING PHOTOTHERAPY • D. De Luca, V. Dell’OrtoABS 7. A PRETERM MODEL OF HYPERBILIRUBINEMIA-INDUCED CEREBELLAR DYSFUNCTION • C.F. Bearer, M. He, J.F. Watchko, J.M. Simard, N. Tang

  13. ICANS-XIV. The fourteenth meeting of the international collaboration on advanced neutron sources

    International Nuclear Information System (INIS)

    Carpenter, J. M.; Tobin, C. A.

    1999-01-01

    The meeting began with a reception on Sunday evening. Monday's plenary sessions included status reports on the four operating spallation neutron sources, IPNS, ISIS, KENS, and the Lujan Center; on the INR source under construction at Troitsk; on the IBR-2 pulsed reactor at Dubna; and on proposals for five new installations. We also heard reports on spin-off activities: the ASTE tests (liquid mercury target tests at the AGS accelerator at Brookhaven), the ACoM activities (developments aimed to provide cold moderators suitable for high-power pulsed sources), and the International Workshop on Cold Moderators for Pulsed Neutron Sources, held in September 1997 at Argonne. Jose Alonso and Bob Macek delivered enlightening invited talks overviewing linear accelerators and rings for spallation neutron sources. The rest of the meeting was devoted to targets and moderators and to instrumentation in a normal rotation of ICANS topics. There were altogether 84 oral reports and 23 poster presentations. On Tuesday and on Wednesday morning, we divided into separate series of sessions on Instrumentation and on Targets and Moderators. In the first, we had reports and discussions on instrumentation and techniques, on computer software, on instrument suites, and on new instruments and equipment. In the second series were sessions on liquid target systems, on solid target systems, on neutron production and target physics, on moderator physics and performance, and on target and moderator neutronics. The Tuesday evening meetings went on until 10:00, making for a 14-hour working day. That everyone willingly endured the long hours is a credit to the dedication of the attendees. On Wednesday afternoon, we boarded buses for the 1-hour trip to Argonne, where attendees toured IPNS and the Advanced Photon Source. Returning to Starved Rock, we enjoyed boat rides on the Illinois River and then a barbecue banquet dinner at the Lodge. All day Thursday and Friday morning, the attendees, in small

  14. High temperature facility TS-3000 K

    International Nuclear Information System (INIS)

    Ion, M.; Padureanu, I.; Mateescu, G.; Radulescu, G.

    1998-01-01

    The high temperature facility TS-3000 K is designed for inelastic and quasielastic slow neutron scattering and neutron diffraction experiments in condensed matter studies over a very large temperature range. A large class of materials is proposed for such kind of investigations: 1. Investigation of oxygen disorder, thermal parameters, lattice vibrations and elastic constants of nuclear fuel oxides as UO 2 , ThO 2 , PuO 2 at temperatures up to 3000 K; 2. Large and small angle neutron scattering experiments on disordered materials; 3. Investigation of the fast ion conductor lattice dynamics (superionic) using neutron scattering techniques; 4. Structure and dynamics of the liquid metals and alloys both in high purity state and with various impurities; 5. Investigation of the materials for fusion reactors at temperatures up to 3000 K; 6. Neutron - dynamics studies of the carbon lattice, its modifications, as well as fullerenes, at high temperature; 7. High temperature mass spectrometric measurements; 8. High purity materials. The facility TS-3000 is running under high internal vacuum conditions (under 10 -6 mbar), water cooled, automatically controlled and stabilized within a very large temperature range (Tmax = 3000 K) for samples of 80 x 80 mm size for inelastic neutron scattering or of a smaller size for diffraction investigation. The temperature is measured either by a wolfram - 5% Rh thermocouple or by direct viewing IR electronic thermometer. First investigations are planned at high intensity and resolution spectrometric complex DIN-2PI setup at the fast pulsed reactor IBR-2 of the Joint Institute for Nuclear Research, Dubna. The main parts of the TS-3000 K facility are: - The furnace with tungsten heater, tungsten, niobium or tantalum shields positioned in an accurate geometry depending of the temperature range and neutron optics (Tmax=3000 K); - The power supply assembly, data acquisition and storage, automatic or manual control; - The power three

  15. Control of Induced and Residual Crystal-Scale Strains on Tensile Failure in Pure Quartzite and Marble

    Science.gov (United States)

    Voigtlaender, A.; Leith, K.; Mueller, B.; Scheffzuek, C.; Schilling, F. R.; Krautblatter, M.

    2016-12-01

    Near surface fracture development in rocks is controlled by a) mineralogical composition, b) applied external loads and environmental chemistry and c) pre-existing microstructure e.g. crystallographic preferred orientation (CPO) and locked-in residual strains. To better understand how some of these factors influence brittle failure of rocks, we undertake staged Brazilian tests under unique in situ conditions at the neutron time-of-flight (TOF) strain diffractometer EPSILON, at the IBR-2M, Dubna, Russia. We measure elastic strains by high resolution TOF diffraction within three cylindrical samples (Ø= 30 mm, l= 22 mm) of pure quartzite (> 98 vol% SiO2, Dalsland quartzite) and two samples of pure marble (> 98 vol% CaCO3, Carrara marble), brought to failure under staged indirect tensile loading. Initial states are measured without load to determine the load-free lattice parameters. Load is increased in three to four stages of approximately 15%, 33%, 66%, and 75-80% of the ultimate intact rock strength, and maintained during diffraction measurements ( 12 hours each). Each load step is ensued by a load-free state. Deviatoric strain in both σ1 and σ3, as well as residual strain, with reference to a strain-free state of powdered samples are calculated for whole diffraction patterns and single Bragg diffraction peaks. Our results provide insight into the mechanical behavior and intra-crystalline strain state of two metamorphic rocks under indirect tensile loading. Both the pre-test quartzite and marble exhibit residual lattice strains of several MPa, reflecting the regional stress field during their formation and exhumation. Superposition of residual strain is already observed following the first load stage in both materials. During subsequent loading stages, inelastic strains accumulate due to grain boundary glides, micro-plasticity and eventually microcracks, promoting the progressive failure of the rock. These results provide insight into the behaviour of rock during

  16. Current tendencies and perspectives of development research reactors of Russia

    International Nuclear Information System (INIS)

    Gabaraev, B.A.; Kchmelschikov, V.V.

    2004-01-01

    Full text: During more than fifty years many Research Reactors were constructed under Russian projects, and that is a considerable contribution to the world reactor building. The designs of Research Reactors, constructed under Russian projects, appeared to be so successful, that permitted to raise capacity and widen the range of their application. The majority of Russian Research Reactors being middle-aged are far from having their designed resources exhausted and are kept on the intensive run still. In 2000 'Strategy of nuclear power development in Russia in the first half of XXI century' was elaborated and approved. The national nuclear power requirements and possible ways of its development determined in this document demanded to analyze the state of the research reactors base. The analysis results are presented in this report. The main conclusion consists in the following statement: on the one hand quantity and experimental potentialities of domestic Research Reactors are sufficient for the solution of reactor materials science tasks, and on the other hand the reconstruction and modernization appears to be the most preferable way of research reactors development for the near-term outlook. At present time the modernization and reconstruction works and works on extension of operational life of high-powered multipurpose MIR-M1, SM-3, IRV-1M, BOR-60, IVV-2M and others are conducted. There is support for the development of Research Reactors, intended for carrying out the fundamental investigations on the neutron beams. Toward this end the Government of Russia gives financial and professional support with a view to complete the reactor PIK construction in PINPh and the reactor IBR-2 modernization in JINR. In future prospect Research Reactors branch in Russia is to acquire the following trends: - limited number of existent scientific centers, based on the construction sites, with high flux materials testing research reactors, equipped with experimental facilities

  17. Current status and prospects of research reactors

    International Nuclear Information System (INIS)

    Gabaraev, A.B.; Cherepnin, Yu.S.; Tretyakov, I.T.; Khmelshikov, V.V.; Dollezhal, N.A.

    2009-01-01

    Full text: The first nuclear research reactors (RR) appeared in the 1940s. Their initial purpose was to provide knowledge of the main processes associated with neutron-induced nuclear reactions. Later, the rang of problems addressed expanded substantially. Besides fundamental research in the properties of matter, such reactors are successfully used for dealing with problems in the fields of materials science, nuclear engineering, medicine, isotope production, education, etc. Over the whole period of RR fleet growth, more than six hundred nuclear research facilities were built in 70 countries of the world. As of the end of 2008, the number of Russian research reactors in service was about 20% of the globally operating RR fleet. This paper discusses the current status of the world's RR fleet and describes the capabilities of the experimental reactor facilities existing in Russia. In the 21st century, research reactors will remain in demand to solve scientific and technological problems for innovative development of society. The emerging renaissance of nuclear power, the expanding RR uses for production of isotopes and other applications, the increase in the number of countries willing to use nuclear technologies in energy production, industry and science - all contribute to a rebirth of interest in research reactors. One of the ways to improve the experimental capabilities lies in radical upgrading of the reactor facilities with qualitative changes in the main neutronic characteristics of the core. The associated design approaches are illustrated with the example of the IBR-2M reactor at the JNRI in Dubna. The imperative need restricting the spread of nuclear threat leads us to give up using highly enriched uranium in most research reactors. Development of RR fuel with reduced enrichment in uranium has been one of the priority objectives of NIKIET for many years. This paper presents the latest results obtained along these lines, as applied to pool-type research

  18. Current trends in and prospects for development of Russian research reactors

    International Nuclear Information System (INIS)

    Arkhangelsky, N.V.; Cherepnin, Yu.S.; Gabaraev, B.A.; Khmelshchikov, V.V.; Tretiyakov, I.T.

    2004-01-01

    Over more than fifty years, many research reactors were built to Russian designs both at home and abroad, which is a considerable contribution to the world reactor engineering. Russian research reactors proved to be successful to an extent that it was found possible to raise capacity and to extend the range of their application. Though having a fairly long operating record, the majority of Russian research reactors are far from the end of their service life and are still in active use. In 2000, the 'Strategy of nuclear power development in Russia in the first half of the 21 st century' was elaborated and approved. The requirements of national nuclear power and the possible ways of its development identified in this document called for assessing the existing research capabilities. The findings of such assessment are presented in this report. The main conclusion lies in the following. On the one hand, the number and experimental capabilities of domestic research reactors are sufficient for coping with the objectives of research in, and on the other hand, retrofitting and upgrading appear to be the most expedient way of managing the operation of research reactors in the near term. Activities are under way to upgrade and extend the service life of multipurpose reactors, such as MIR-M1, SM-3, IRV-1M, BOR-60, IVV-2M, and others. The Federal Agency of the Russian Federation for Atomic Energy (Rosatom) supports the development of reactors intended for fundamental research with the use of neutron beams. To this end, Rosatom renders financial and professional support with a view to complete the PIK reactor construction at PIYaF and the IBR-2 reactor upgrades at JINR. In a longer term, the development of research reactors in Russia is expected to have the following pattern: - a small number of high-flux testing reactors with up-to-date experimental facilities located on the sites of the existing research centers; - PIK reactor, catering to domestic and foreign needs for beam

  19. III International Conference on Small Angle Neutron Scattering dedicated to the 80 anniversary of Yu.M. Ostanevich

    International Nuclear Information System (INIS)

    2017-01-01

    Preface “Among the many well-known fundamental and applied consequences of neutron discovery, one of the first was the emergence of structural neutron diffraction - one of the methods for studying the spatial structure of condensed matter at the atomic level. Investigating the dynamics of biological macromolecules by neutron diffraction methods is an area that is almost untouched. We believe that also in this direction one should expect rapid progress.” Yu.M.Ostanevich and I.N.Serdyuk Uspekhi Fizicheskih Nauk (1982) More than 30 years after Ostanevich and Serdyuk reviewed the then 50 years from the neutron discovery, we are happy to support their statement and prediction by reporting on the further progress in the field of neutron scattering research. Frank Laboratory of Neutron Physics has organized the III International Conference on Small Angle Neutron Scattering (YuMO2016) that was – not coincidently – dedicated to the 80th anniversary of Ostanevich. Yuriy Mechislavovich Ostanevich (1936–1992) has had a determinative and crucial contribution to the construction of spectrometers at the pulsed reactor IBR in Dubna, Russia. He contributed in particular to the development of time-of-flight small-angle neutron scattering (SANS) technique, and the selection of advanced scientific areas for its application. The SANS instrument at the IBR-2 reactor is called YuMO in his honour. The Ostanevich’s leadership and outstanding scientific achievements in SANS studies of polyelectrolytes, small molecules, fractals, metallic glasses, macromolecules, polymers, etc., were recognized also by a number of awards including the State Prize of the Russian Federation in 2000. To this end of course, we should not forget mentioning the contribution of close collaborators of Ostanevich: Laszlo Cser, Josef Plestil as well as Alexander Kunchenko, Vadim Bezzabotnov and Nikolay Gorski. The YuMO2016 conference focused on providing opportunities to discuss various possibilities of

  20. Department of Structural Research - Overview

    International Nuclear Information System (INIS)

    Wasiutynski, T.

    2002-01-01

    at the Dubna IBR-2 reactor. As a part of a larger project undertaken with Institute for Energietekknik (Kjeller, Norway) the low energy excitations have been studied in a glass and in two crystalline phases of the glass-forming triphenyl phosphite. Results of investigations of the dynamics of the methyl groups in the crystalline phase of 1,3,5,-(CH 3 ) 3 C 6 H 3 have been used during a testing procedure of computer simulation of the molecular dynamics based on the quantum chemistry methods. Neutron scattering is also used to investigate properties of polymers: polymer electrolytes and blends. Deep inelastic (''Compton'') scattering was applied to find the relation between stretching of the samples and kinetic energy of particular nuclei (the method capable of detecting potential anharmonicity). Structural factors affecting polymer miscibility were further studied by polarized neutron scattering techniques. In this research we cooperate with the Open University, Oxford, UK. Our theoretical studies concern phase transitions in molecular crystals as well as general dynamical properties of anharmonic surfaces and other structural defects. For an isomorphous phase transitions in the mixture of the fullerenes C 70(1-x) C 60x the highly anisotropic pseudospin model has been proposed, which turned out to be equivalent to the Ising model with two states of different statistical weights. The prediction of a disordered low temperature crystal has been confirmed by the dilatometric data. Delayed differential equantions governing the propagation of waves through an anharmonic defect have been solved with the use of an analogous electric circuit. Similar equations have been proposed to explain the deviation of the Curie constants from their mean field approximation values due to anharmonic effects in the temperature range close to the phase transition. Magnetic investigations have been performed for a wide scope of materials. For ternary 4f - 4d, 5d intermetallic compounds