WorldWideScience

Sample records for nuclear decay scheme

  1. Evaluation of β intensity data in nuclear decay schemes: comments on some pitfalls

    International Nuclear Information System (INIS)

    Reich, C.W.

    1986-01-01

    Some of the problems which arise in the evaluation of decay-schemes data to obtain values for the intensities of β transitions are discussed. As examples of these problems, the decay schemes of 87 Br and 233 Pa are examined. No specific solutions to these problems are offered; but by pointing them out to the participants in the International Nuclear Structure and Decay Data Evaluation Network, it is hoped that a general understanding of them can be gained, which may ultimately lead to a consistent means of dealing with them. 14 refs., 2 figs., 1 tab

  2. MIRD radionuclide data and decay schemes

    CERN Document Server

    Eckerman, Keith F

    2007-01-01

    For all physicians, scientists, and physicists working in the nuclear medicine field, the MIRD: Radionuclide Data and Decay Schemes updated edition is an essential sourcebook for radiation dosimetry and understanding the properties of radionuclides. Includes CD Table of Contents Decay schemes listed by atomic number Radioactive decay processes Serial decay schemes Decay schemes and decay tables This essential reference for nuclear medicine physicians, scientists and physicists also includes a CD with tabulations of the radionuclide data necessary for dosimetry calculations.

  3. Induced nuclear beta decay

    International Nuclear Information System (INIS)

    Reiss, H.R.

    1986-01-01

    Certain nuclear beta decay transitions normally inhibited by angular momentum or parity considerations can be induced to occur by the application of an electromagnetic field. Such decays can be useful in the controlled production of power, and in fission waste disposal

  4. Study of 228Ac decay scheme

    International Nuclear Information System (INIS)

    Pinto, H.V.

    1976-02-01

    Calibration in energy and efficiency of the system used. Obtainement of singles gamma ray spectra of low and high energy. Reduction of the data obtained in the spectrometer by means of computer: localization and determination of the areas of the peaks, also the analysis of the shape of the peaks for identification of doublets. Checking of the decay scheme [pt

  5. Single particle level scheme for alpha decay

    International Nuclear Information System (INIS)

    Mirea, M.

    1998-01-01

    The fine structure phenomenon in alpha decay was evidenced by Rosenblum. In this process the kinetic energy of the emitted particle has several determined values related to the structure of the parent and the daughter nucleus. The probability to find the daughter in a low lying state was considered strongly dependent on the spectroscopic factor defined as the square of overlap between the wave function of the parent in the ground state and the wave functions of the specific excited states of the daughter. This treatment provides a qualitative agreement with the experimental results if the variations of the penetrability between different excited states are neglected. Based on single particle structure during fission, a new formalism explained quantitatively the fine structure of the cluster decay. It was suggested that this formalism can be applied also to alpha decay. For this purpose, the first step is to construct the level scheme of this type of decay. Such a scheme, obtained with the super-asymmetric two-center potential, is plotted for the alpha decay of 223 Ra. It is interesting to note that, diabatically, the level with spin 3/2 emerging from 1i 11/2 (ground state of the parent) reaches an excited state of the daughter in agreement with the experiment. (author)

  6. Catalog of gamma-rays unplaced in radioactive decay schemes

    International Nuclear Information System (INIS)

    Narita, Tsutomu; Kitao, Kensuke.

    1991-03-01

    A catalog is made for gamma-rays emitted in decay of radioactive nuclides but not placed in their decay schemes. It consists of two tables. In Table 1, the number of these unplaced gamma-ray components by a nuclide is given together with the fraction of total intensity of these gamma-rays to that of all observed gamma-rays. In Table 2, the unplaced gamma-rays are arranged in order of increasing energy. Each line of this table contains the gamma-ray energy, intensity, nuclide identification, and energies and intensities of the most prominent gamma-rays from the decay of the radionuclides. This catalog is a compilation from Evaluated Nuclear Structure Data File (ENSDF) maintained by National Nuclear Data Center at Brookhaven National Laboratory, of at February 1990. (author)

  7. Complex beta-decay schemes: Pandemonium lost and paradise regained

    International Nuclear Information System (INIS)

    Firestone, R.B.

    1982-01-01

    The β-decay of 145 Gd has been studied in sufficient detail for comparison with the decay of its fictional analogue Pandemonium. It is shown that > 98% of the 145 Gd decay intensity was observed. This result casts doubt on the value of decay schemes determined solely by statistical techniques. (orig.)

  8. Nuclear double beta decay

    International Nuclear Information System (INIS)

    Hubert, P.; Mennrath, P.

    1985-01-01

    The processes of double beta decay with and without emission of neutrinos are briefly reviewed. After the definitions of the processes and implications for the neutrino properties, the present status of the experimental results is discussed. We conclude with a description of the Bordeaux-Zaragoza-Strasbourg experimental which will run in the Frejus tunnel

  9. Decay scheme of the U235

    International Nuclear Information System (INIS)

    Gaeta, R.

    1965-01-01

    A study of the Th 2 31 excited levels from the alpha decay of the U 2 35, is carried out. The alpha particle spectrum was measured by means of a semiconductor counter spectrometer with an effective resolution of 18 keV. Nineteen new lines were identified. The gamma-ray spectrum was measured with thin samples of U 2 35, free from decay products, and in such geometrical conditions, that most of the interference effects were eliminated. The gamma-gamma coincidence spectra have made easier a better knowledge of the transition between the several levels. (Author) 110 refs

  10. Nuclear Structure and Decay Data (NSDD) network

    International Nuclear Information System (INIS)

    Pronyaev, V.G.

    2001-02-01

    This report provides a brief description of the Nuclear Structure and Decay Data (NSDD) Network in response to a request from the Advisory Group Meeting on ''Co-ordination of the International Network of Nuclear Structure and Decay Data Evaluators'' (IAEA, Vienna, 14-17 December 1998, report IAEA(NDS)-399 (1999)). This report supersedes the special issue of the Nuclear Data Newsletter No. 20 published in November 1994. (author)

  11. Nuclear beta decay and the weak interaction

    International Nuclear Information System (INIS)

    Kean, D.C.

    1975-11-01

    Short notes are presented on various aspects of nuclear beta decay and weak interactions including: super-allowed transitions, parity violation, interaction strengths, coupling constants, and the current-current formalism of weak interaction. (R.L.)

  12. Nuclear structure and double beta decay

    International Nuclear Information System (INIS)

    Vogel, P.

    1988-01-01

    Double beta decay is a rare transition between two nuclei of the same mass number A involving a change of the nuclear charge Z by two units. It has long been recognized that the Oν mode of double beta decay, where two electrons and no neutrinos are emitted, is a powerful tool for the study of neutrino properties. Its observation would constitute a convincing proof that there exists a massive Majorana neutrino which couples to electrons. Double beta decay is a process involving an intricate mixture of particle physics and physics of the nucleus. The principal nuclear physics issues have to do with the evaluation of the nuclear matrix elements responsible for the decay. If the authors wish to arrive at quantitative answers for the neutrino properties the authors have no choice but to learn first how to understand the nuclear mechanisms. The authors describe first the calculation of the decay rate of the 2ν mode of double beta decay, in which two electrons and two antineutrinos are emitted

  13. Helicity and nuclear β decay correlations

    Science.gov (United States)

    Hong, Ran; Sternberg, Matthew G.; Garcia, Alejandro

    2017-01-01

    We present simple derivations of nuclear β-decay correlations with an emphasis on the special role of helicity. This topic provides a good opportunity to teach students about helicity and chirality in particle physics with exercises that use simple aspects of quantum mechanics. In addition, this paper serves as an introduction to nuclear β-decay correlations from both a theoretical and experimental perspective. This article can be used to introduce students to ongoing experiments searching for hints of new physics in the low-energy precision frontier.

  14. Nuclear decay data files of the Dosimetry Research Group

    International Nuclear Information System (INIS)

    Eckerman, K.F.; Westfall, R.J.; Ryman, J.C.; Cristy, M.

    1993-12-01

    This report documents the nuclear decay data files used by the Dosimetry Research Group at Oak Ridge National Laboratory and the utility DEXRAX which provides access to the files. The files are accessed, by nuclide, to extract information on the intensities and energies of the radiations associated with spontaneous nuclear transformation of the radionuclides. In addition, beta spectral data are available for all beta-emitting nuclides. Two collections of nuclear decay data are discussed. The larger collection contains data for 838 radionuclides, which includes the 825 radionuclides assembled during the preparation of Publications 30 and 38 of the International Commission on Radiological Protection (ICRP) and 13 additional nuclides evaluated in preparing a monograph for the Medical Internal Radiation Dose (MIRD) Committee of the Society of Nuclear Medicine. The second collection is composed of data from the MIRD monograph and contains information for 242 radionuclides. Abridged tabulations of these data have been published by the ICRP in Publication 38 and by the Society of Nuclear Medicine in a monograph entitled ''MIRD: Radionuclide Data and Decay Schemes.'' The beta spectral data reported here have not been published by either organization. Electronic copies of the files and the utility, along with this report, are available from the Radiation Shielding Information Center at Oak Ridge National Laboratory

  15. Schemes of radioactive decay, its interpretations in the scope of the radiological protection

    International Nuclear Information System (INIS)

    Mohamad, N.; Caro, R.A.; Bergoc, R.M.

    1998-01-01

    Full text: In our teaching experience we have verified that the interpretation of the symbols of radioactive decay schemes is one of the most difficult subject in the study of radioisotope methodologies for almost all professionals, and specially for those who have no solid background in mathematics or physics. The correct interpretation of decay schemes has fundamental importance for the proper election of measurement conditions and for performing the dosimetric and shielding calculations. Nuclides employed in Nuclear Medicine and Biomedicine are beta, gamma or beta/gamma emitters. Interpretation of decay schemes of beta emitters, by β + , β - or electronic capture are not difficult. In gamma emitting nuclides it is frequent that a particular level of energy is de-excited through more than one gamma transition of a given percentage and energy. On the other hand, it is also frequent that conversion electrons are emitted together with gamma photons, the proportion of which is usually given as the conversion factor, e/γ. The fraction of emitted photons is calculated as: 1 / [1+ (e/γ)], whereas the fraction of emitted conversion electrons is equal to: (e/γ) / [1+ (e/γ)]. Special attention should be given to the post-accommodation mechanism after disintegration in which orbital vacancies are produced: electron conversion or electron capture, in which the emission of X-rays and Auger electrons occur. All this information should be taken into account for the correct choice of measurement conditions, as well as internal and external dose calculations. In the present work we describe the analysis and interpretation of disintegration schemes in general and that of the most employed nuclides in Nuclear Medicine and Biomedicine. (author) [es

  16. Compilations and evaluations of nuclear structure and decay data

    International Nuclear Information System (INIS)

    Lorenz, A.

    1978-10-01

    This is the fourth issue of a report series on published and to-be-published compilations and evaluations of nuclear structure and decay (NSD) data. This compilation is published and distributed by the IAEA Nuclear Data Section every year. The material contained in this compilation is sorted according to eight subject categories: General compilations; basic isotopic properties; nuclear structure properties; nuclear decay processes, half-lives, energies and spectra; nuclear decay processes, gamma-rays; nuclear decay processes, fission products; nuclear decay processes (others); atomic processes

  17. Present and future nuclear power financing schemes

    International Nuclear Information System (INIS)

    Diel, R.

    1977-01-01

    The financial requirement for nuclear power plants in the Federal Republic of Germany for the period up until 1985 was estimated to run up to some DM 100 billion already in the Nuclear Energy Study published by the Dresdner Bank in 1974. This figure is not changed in any way by the reduction the nuclear power program has suffered in the meantime, because the lower requirement for investment capital is more than offset by the price increases that have occurred meanwhile. A capital requirement in the order of DM 100 billion raises major problems for the power producing industry and the banks which, however, are not going to hamper the further expansion of nuclear power, because new financing schemes have been specially developed for the nuclear field. They include financing by leasing, the use of funds from real estate credit institutions for long term financing, borrowing of long term funds in the Euro market, and financing through subsidiaries of the utilities. The new financing schemes also apply to the large financial requirement associated with the nuclear fuel cycle, waste management in particular. In this sector the utilities agree to bear the economic risk of the companies implementing the respective projects. Accordingly, financing will not entail any major difficulties. Another area of great importance is export financing. The German-Brazilian nuclear agreement is a model of this instrument. (orig.) [de

  18. Weak interaction studies from nuclear beta decay

    International Nuclear Information System (INIS)

    Morita, M.

    1981-01-01

    The studies performed at the theoretical nuclear physics division of the Laboratory of Nuclear Studies, Osaka University, are reported. Electron spin density and internal conversion process, nuclear excitation by electron transition, beta decay, weak charged current, and beta-ray angular distributions in oriented nuclei have been studied. The relative intensity of internal conversion electrons for the case in which the radial wave functions of orbital electrons are different for electron spin up and down was calculated. The calculated value was in good agreement with the experimental one. The nuclear excitation following the transition of orbital electrons was studied. The calculated probability of the nuclear excitation of Os 189 was 1.4 x 10 - 7 in conformity with the experimental value 1.7 x 10 - 7 . The second class current and other problems on beta-decay have been extensively studied, and described elsewhere. Concerning weak charged current, the effects of all induced terms, the time component of main axial vector, all partial waves of leptons, Coulomb correction for the electrons in finite size nuclei, and radiative correction were studied. The beta-ray angular distribution for the 1 + -- 0 + transition in oriented B 12 and N 12 was investigated. In this connection, investigation on the weak magnetism to include all higher order corrections for the evaluation of the spectral shape factors was performed. Other works carried out by the author and his collaborators are also explained. (Kato, T.)

  19. Enhanced nuclear level decay in hot dense plasmas

    International Nuclear Information System (INIS)

    Gosselin, G.; Morel, P.

    2004-01-01

    A model of nuclear level decay in a plasma environment is described. Nuclear excitation and decay by photon processes, nuclear excitation by electron capture, and decay by internal conversion are taken into account. The electrons in the plasma are described by a relativistic average atom model for the bound electrons and by a relativistic Thomas-Fermi-Dirac model for the free electrons. Nuclear decay of isomeric level may be enhanced through an intermediate level lying above the isomer. An enhanced nuclear decay rate may occur for temperatures far below the excitation energy of the transition to the intermediate level. In most cases, the enhancement factor may reach several decades

  20. Compilations and evaluations of nuclear structure and decay data

    International Nuclear Information System (INIS)

    Lorenz, A.

    1977-03-01

    This is the second issue of a report series on published and to-be-published compilations and evaluations of nuclear structure and decay (NSD) data. This compilation of compilations and evaluations is designed to keep the nuclear scientific community informed of the availability of compiled or evaluated NSD data, and contains references to laboratory reports, journal articles and books containing selected compilations and evaluations. It excludes references to ''mass-chain'' evaluations normally published in the ''Nuclear Data Sheets'' and ''Nuclear Physics''. The material contained in this compilation is sorted according to eight subject categories: general compilations; basic isotopic properties; nuclear structure properties; nuclear decay processes; half-lives, energies and spectra; nuclear decay processes: gamma-rays; nuclear decay processes: fission products; nuclear decay processes: (others); atomic processes

  1. Statistical view on nuclear multifragmentation: Primary decays

    International Nuclear Information System (INIS)

    Raduta, A.H.; Raduta, A.R.

    1997-01-01

    An overall view on the universe of primary decays appearing in the process of nuclear multifragmentation via a microcanonical Monte Carlo Metropolis type simulation is given. General characteristics like mass and charge distributions, relative probabilities of evaporation, fission, fragmentation and vaporization, average number of fragments and distributions of a number of intermediate mass fragments offer valuable information about the intimacy of the process. The capability of the model to describe unitary very different breakup regimes is pointed out. Predictions for charge distributions, isotopic yields, and fission mass distributions are compared with experimental data. copyright 1997 The American Physical Society

  2. Strong renormalization scheme dependence in τ-lepton decay: Fact or fiction?

    International Nuclear Information System (INIS)

    Chyla, J.

    1995-01-01

    The question of the renormalization scheme dependence of the τ semileptonic decay rate is examined in response to a recent criticism. Particular attention is payed to a distinction between a consistent quantitative description of this dependence and the actual selection of a subset of ''acceptable'' renormalization schemes. It is pointed out that this criticism is valid only within a particular definition of the ''strength'' of the renormalization scheme dependence and should not discourage further attempts to use the semileptonic τ decay rate for quantitative tests of perturbative QCD

  3. Retrieval program system of Chinese Evaluated (frequently useful) Nuclear Decay Database

    International Nuclear Information System (INIS)

    Huang Xiaolong; Zhou Chunmei

    1995-01-01

    The Chinese Evaluated (frequently useful) Nuclear Decay Database has been set up in MICRO-VAX-11 computer at Chinese Nuclear Data Center (CNDC). For users' convenience, the retrieval program system of the database is written. Retrieval can be carried out for one nucleus or multi-nucleus. The retrieved results can be displayed on terminal screen or output to M3081 printer and laser printer in ENSDF format, table report or scheme diagrams

  4. Statistical models for nuclear decay from evaporation to vaporization

    CERN Document Server

    Cole, A J

    2000-01-01

    Elements of equilibrium statistical mechanics: Introduction. Microstates and macrostates. Sub-systems and convolution. The Boltzmann distribution. Statistical mechanics and thermodynamics. The grand canonical ensemble. Equations of state for ideal and real gases. Pseudo-equilibrium. Statistical models of nuclear decay. Nuclear physics background: Introduction. Elements of the theory of nuclear reactions. Quantum mechanical description of scattering from a potential. Decay rates and widths. Level and state densities in atomic nuclei. Angular momentum in quantum mechanics. History of statistical

  5. Periodicities in Nuclear Decay Data: Systematic Effects or New Physics?

    International Nuclear Information System (INIS)

    Recent comparisons of independent and unrelated nuclear decay experiments have shown unexplained oscillations that appear to be common in frequency and phase. The most logical explanation for this fluctuation would be some common systematic or environmental factor. In this paper we provide detailed spectral analysis comparisons of several environmental factors with nuclear decay data from an experiment performed at the Brookhaven National Laboratory. We demonstrate that, although none of the environmental factors investigated can be causal, comparisons with ACRIM solar irradiance measurements provide good agreement with the nuclear decay data. This analysis provides the first direct evidence that the cause of the fluctuations has a possible solar origin.

  6. Nuclear structure and radioactive decay resources at the US National Nuclear Data Center

    International Nuclear Information System (INIS)

    Sonzogni, A.A.; Burrows, T.W.; Pritychenko, B.; Tuli, J.K.; Winchell, D.F.

    2008-01-01

    The National Nuclear Data Center has a long tradition of evaluating nuclear structure and decay data as well as offering tools to assist in nuclear science research and applications. With these tools, users can obtain recommended values for nuclear structure and radioactive decay observables as well as links to the relevant articles. The main databases or tools are ENSDF, NSR, NuDat and the new Endf decay data library. The Evaluated Nuclear Structure Data File (ENSDF) stores recommended nuclear structure and decay data for all nuclei. ENSDF deals with properties such as: -) nuclear level energies, spin and parity, half-life and decay modes, -) nuclear radiation energy and intensity for different types, -) nuclear decay modes and their probabilities. The Nuclear Science References (NSR) is a bibliographic database containing nearly 200.000 nuclear sciences articles indexed according to content. About 4000 are added each year covering 80 journals as well as conference proceedings and laboratory reports. NuDat is a software product with 2 main goals, to present nuclear structure and decay information from ENSDF in a user-friendly way and to allow users to execute complex search operations in the wealth of data contained in ENSDF. The recently released Endf-B7.0 contains a decay data sub-library which has been derived from ENSDF. The way all these databases and tools have been offered to the public has undergone a drastic improvement due to advancements in information technology

  7. Radioactive decays at limits of nuclear stability

    DEFF Research Database (Denmark)

    Pfützner, M.; Karny, M.; Grigorenko, L. V.

    2012-01-01

    The last decades brought impressive progress in synthesizing and studying properties of nuclides located very far from the beta stability line. Among the most fundamental properties of such exotic nuclides, the ones usually established first are the half-life, possible radioactive decay modes...... state. A review of the decay modes occurring close to the limits of stability is presented. The experimental methods used to produce, identify, and detect new species and their radiation are discussed. The current theoretical understanding of these decay processes is reviewed. The theoretical...... description of the most recently discovered and most complex radioactive process—the two-proton radioactivity—is discussed in more detail....

  8. Compilations and evaluations of nuclear structure and decay data

    International Nuclear Information System (INIS)

    Lorenz, A.

    1977-10-01

    This is the third issue of a report series on published and to-be-published compilations and evaluations of nuclear structure and decay (NSD) data. This compilation is published and distributed by the IAEA Nuclear Data Section approximately every six months. This compilation of compilations and evaluations is designed to keep the nuclear scientific community informed of the availability of compiled or evaluated NSD data, and contains references to laboratory reports, journal articles and books containing selected compilations and evaluations

  9. Double β-decay nuclear matrix elements and lepton conservation

    International Nuclear Information System (INIS)

    Vergados, J.D.

    1976-01-01

    The nuclear matrix elements involved in the double β-decay of 48 Ca, 130 Te, and 128 Te were calculated using realistic nuclear interactions and shell model nuclear wave functions. The double doorway state is not appreciably mixed in the ground state of the final nuclei. So the ground state transitions contain a small fraction of the sum rule. A lepton nonconservation parameter eta -4 was deduced

  10. Recruitment schemes in new nuclear projects

    International Nuclear Information System (INIS)

    Tielas, M.

    2012-01-01

    Contracting in New Nuclear Projects: A collaborative model between the Owner and the Supplier is described for building nuclear power plants, and is being implemented in the USA as well as in Europe to solve the problem of the risk in the initial investment as experienced in the past: widely exceeded budgets and construction schedules. (Author)

  11. Track reconstruction of normal muon decays in the LAMPF TPC: one working scheme

    International Nuclear Information System (INIS)

    McKee, R.J.

    1983-01-01

    A working scheme for track reconstruction of normal muon decays in the LAMPF TPC is here outlined. Muon tracks stopping in the TPC and helical electron tracks from muon decay are both identified and fitted for complete event reconstruction. Because of certain geometrical characteristics of the TPC, novel techniques are deployed to find the tracks. Normal road tracing methods do not work reliably; they are replaced by, among other things, a random search technique that locates the helix's planar projection and a carefully worked-out method for correctly putting each coordinate on its proper turn in the helix

  12. Nuclear Structure Aspects of Neutrinoless Double-β Decay

    Science.gov (United States)

    Brown, B. A.; Horoi, M.; Sen'kov, R. A.

    2014-12-01

    We decompose the neutrinoless double-β decay matrix elements into sums of products over the intermediate nucleus with two less nucleons. We find that the sum is dominated by the Jπ=0+ ground state of this intermediate nucleus for both the light and heavy neutrino decay processes. This provides a new theoretical tool for comparing and improving nuclear structure models. It also provides the connection to two-nucleon transfer experiments.

  13. Proton decay in a nucleus: Nonrelativistic treatment of nuclear effects

    International Nuclear Information System (INIS)

    Fernandez, L.A.; Alvarez-Estrada, R.F.; Sanchez-Gomez, J.L.

    1983-01-01

    In this paper, proton decay in a large nucleus is studied in the framework of SU(5) grand unification theory (GUT). By using a method based upon the Green's-function technique of many-body physics, nuclear effects on spectator and pole terms are computed. The decay width in the nucleus is found to be practically the same as in free space. However, nuclear effects are of considerable importance concerning the positron spectrum. A density-correlation expansion is introduced which is useful for carrying out a systematic study of nuclear effects in proton decay in a large nucleus. The method presented here can be easily extended to other GUT's or supersymmetric GUT's

  14. Nuclear structure of the transactinides – investigated by decay spectroscopy

    Directory of Open Access Journals (Sweden)

    Heßberger Fritz Peter

    2016-01-01

    Full Text Available Superheavy elements owe their stability due to a subtle balance between the disruptive Coulomb force and the attractive nuclear forces. Thus they represent an ideal laboratory to study basic interactions. The essential tools are detailed investigations of radioactive decay properties and nuclear structure of superheavy nuclei. The results of those studies will deliver valuable input to improve theoretical models. To fulfill this demand conclusive data of high quality are necessary, which is presently not so easy to meet due to small production cross sections and technical limitations (beam intensities, detection probabilities. Possibilities and problems concerning extraction of decay properties and nuclear structure information on the basis of a low number of observed decay events will be discussed for three illustrative examples, 257Rf, 257Lr, and 288Fl.

  15. Data processing in gamma spectrometry. Application to the decay schemes study

    International Nuclear Information System (INIS)

    Boulanger, J.P.

    1969-06-01

    The purpose of this thesis is the processing of the data issued from a gamma spectrometer, and its applications to the decay schemes study. The mathematical analysis of the full energy peaks, in connection with the very good resolution of semi-conductor detectors, leads to a very accurate determination of the energies. The resolution of complex spectra by the least squares method, completed by a spectra generating process, allows the calculation of branching ratios. Then, the handling of the two dimensional experiments permits the coincidence exam. For each of these methods, the calculation principle, then the systematics tests realized in order to prove their validity and to determine their application ranges as well as some experimental results appropriate to illustrate their possibilities, are presented. The energies of some nuclides, frequently used as standards have been thus measured and the decay schemes of 134 Cs and 110m Ag determined precisely. (author) [fr

  16. Nuclear beta decay induced by intense electromagnetic fields: Basic theory

    International Nuclear Information System (INIS)

    Reiss, H.R.

    1983-01-01

    A basic formalism is developed for the theory of the effect on nuclear beta decay of an intense, plane-wave electromagnetic field. Interactions of the field with both the nuclear particles and the decay electron are included. The formalism is developed from first principles, including a derivation of transition probabilities between explicitly time-dependent asymptotic states. Interaction of the field with the nucleus is analyzed in terms of separation of the nucleus into an inert core and a fragment. The field interacts with the fragment, consisting of the nucleons which are candidates for beta decay, plus any other nucleons angular-momentum coupled to them in initial or final states. A separation of variables in the dynamical equations for the nucleus into center-of-mass and relative coordinates for the core and fragment shows direct charge coupling even for a fragment consisting entirely of neutrons. The transition formalism involves specific intense-field wave functions both for the nucleus and for the beta particle. Complete results are presented for total transition probability per unit time for intense-field-coupled nuclear beta decay. A much simplified formalism is given for the special case of very high field intensity at very low frequency. The results then bear a formal resemblance to ordinary beta decay theory, but they contain specific field effects in the beta particle spectral function, and in the nuclear interaction matrix elements. This is the first of a series of papers on this subject

  17. A new MV bus transfer scheme for nuclear power plants

    Directory of Open Access Journals (Sweden)

    Chang Choong-Koo

    2015-01-01

    Full Text Available Fast bus transfer method is the most popular and residual voltage transfer method that is used as a backup in medium voltage buses in general. The use of the advanced technology like open circuit voltage prediction and digital signal processing algorithms can improve the reliability of fast transfer scheme. However, according to the survey results of the recent operation records in nuclear power plants, there were many instances where the fast transfer scheme has failed. To assure bus transfer in any conditions and circumstances, uninterruptible bus transfer scheme utilizing the state of the art medium voltage UPS is discussed and elaborated.

  18. Compilation of nuclear decay data used for dose calculation. Revised data for radionuclides listed in ICRP Publication 38

    International Nuclear Information System (INIS)

    Endo, Akira; Yamaguchi, Yasuhiro

    2001-03-01

    New nuclear decay data used for dose calculation have been compiled for 817 radionuclides that are listed in ICRP Publication 38 (Publ. 38) and for 6 additional isomers. The decay data were prepared using decay data sets from the Evaluated Nuclear Structure Data File (ENSDF), the latest version in August 1997. Basic nuclear properties in the decay data sets that are particularly important for calculating energies and intensities of emissions were examined and updated by referring to NUBASE, the database for nuclear and decay properties of nuclides. The reviewed and updated data were half-life, decay mode and its branching ratio, spin and parity of the ground and isomeric states, excitation energy of isomers, and Q value. In addition, possible revisions of partial and incomplete decay data sets were done for their format and syntax errors, level schemes, normalization records, and so on. After that, the decay data sets were processed by EDISTR in order to compute the energies and intensities of α particles, β particles, γ rays, internal conversion electrons, X rays, and Auger electrons emitted in nuclear transformation. For spontaneously fissioning nuclides, the average energies and intensities of neutrons, fission fragments, prompt γ rays, delayed γ rays, and β particles were also calculated. The compiled data were prepared in two different types of format: Publ. 38 and NUCDECAY formats. Comparison of the compiled decay data with those in Publ. 38 was also presented. The decay data will be widely used for internal and external dose calculations in radiation protection and will be beneficial to a future revision of ICRP Publ. 38. (author)

  19. Evidence against solar influence on nuclear decay constants

    Directory of Open Access Journals (Sweden)

    S. Pommé

    2016-10-01

    Full Text Available The hypothesis that proximity to the Sun causes variation of decay constants at permille level has been tested and disproved. Repeated activity measurements of mono-radionuclide sources were performed over periods from 200 days up to four decades at 14 laboratories across the globe. Residuals from the exponential nuclear decay curves were inspected for annual oscillations. Systematic deviations from a purely exponential decay curve differ from one data set to another and are attributable to instabilities in the instrumentation and measurement conditions. The most stable activity measurements of alpha, beta-minus, electron capture, and beta-plus decaying sources set an upper limit of 0.0006% to 0.008% to the amplitude of annual oscillations in the decay rate. Oscillations in phase with Earth's orbital distance to the Sun could not be observed within a 10−6 to 10−5 range of precision. There are also no apparent modulations over periods of weeks or months. Consequently, there is no indication of a natural impediment against sub-permille accuracy in half-life determinations, renormalisation of activity to a distant reference date, application of nuclear dating for archaeology, geo- and cosmochronology, nor in establishing the SI unit becquerel and seeking international equivalence of activity standards.

  20. Nuclear beta decay far from stability and astrophysics

    International Nuclear Information System (INIS)

    Klapdor, H.V.

    1988-01-01

    Beta decay data of nuclei far from stability are one of the most important nuclear physics input for the understanding of the element systhesis in the universe and determination of the age of the universe from cosmochronometers and by the latter have implications also for cosmology. The present status of theoretical predictions of beta decay far from stability will be reviewed and the impact on the above astrophysical questions will be outlined. First results of second generation microscopic calculations of β F half lives, which are at present in progress, will be presented. (orig.)

  1. Heavy particle decay studies using different versions of nuclear potentials

    Science.gov (United States)

    Santhosh, K. P.; Sukumaran, Indu

    2017-10-01

    The heavy particle decay from 212-240Pa , 219-245Np , 228-246Pu , 230-249Am , and 232-252Cm leading to doubly magic 208Pb and its neighboring nuclei have been studied using fourteen versions of nuclear potentials. The study has shown that the barrier penetrability as well as the decay half-lives are found to vary with the nuclear potential used. The investigated decay events of the emission of the clusters 22Ne , 24Ne , 26Mg , 28Mg , 32Si and 33Si are not experimentally detected yet but may be detectable in the future. As most of the half-lives predicted are found to lie within the experimental upper limit, T 1/2 parents with varying slopes and intercepts. Also, it is to be noted that the linearity of the GN plots is unaltered using different nuclear potentials. The universal curve studied ( log10 T 1/2 vs. -ln P for various clusters emitted from various parents shows a linear behavior with the same slope and intercept irrespective of the nuclear potential used.

  2. Nuclear data newsletter. No. 20. Nuclear structure and decay data network

    International Nuclear Information System (INIS)

    1994-11-01

    This special issue of the Nuclear Data Newsletter dated November 1994 gives information on the Nuclear Structure and Decay Data (NSDD) Network established in 1974 under the auspices of the IAEA and comprising 17 laboratories and universities in 10 countries. The procedures for online access to US National Nuclear Data Center, NEA Data Bank in Paris and IAEA Nuclear Data Section in Vienna are presented

  3. Alpha-decay within Feshbach theory of nuclear reactions

    International Nuclear Information System (INIS)

    Sandulescu, A.; Silisteanu, I.; Wunsch, R.

    1977-01-01

    In the frame of Feshbach theory of nuclear reactions the alpha-decay widths are determined by the alpha-daughter nucleus optical potential and by the formation factors. It is shown that the calculated absolute values of the alpha widths for Po light isotopes are in good agreement with experimental data, if the real part of the optical potential with the parameters fitted by the low energy α-scattering is used

  4. NUCLEAR STRUCTURE AND DECAY DATA: INTRODUCTION TO RELEVANT WEB PAGES

    International Nuclear Information System (INIS)

    BURROWS, T.W.; MCLAUGHLIN, P.D.; NICHOLS, A.L.

    2005-01-01

    A brief description is given of the nuclear data centres around the world able to provide access to those databases and programs of highest relevance to nuclear structure and decay data specialists. A number of Web-page addresses are also provided for the reader to inspect and investigate these data and codes for study, evaluation and calculation. These instructions are not meant to be comprehensive, but should provide the reader with a reasonable means of electronic access to the most important data sets and programs

  5. Clarification of nuclear risk recognition scheme through dialogue forum

    International Nuclear Information System (INIS)

    Yagi, Ekou; Takahashi, Makoto; Kitamura, Masaharu

    2007-01-01

    The design framework and operational guidelines for conducting repetitive dialogue between public and nuclear engineers are described in this paper. An action research project named repetitive dialogue forum has been conducted in two municipalities where nuclear facilities were sited. The qualitative evaluation by public participants indicated that the public trust in the nuclear experts, known as the crucial factor for meaningful communication, was successfully established through the dialogue forum. In addition, the expert showed a marked psychological change from distrust to trust in public. Through a detailed analysis of the comments of the participants raised during the forums, the nuclear risk recognition scheme of the public was clarified. The constituents of the risk recognition scheme about nuclear facilities were identified as follows. The first is related to the technical risk recognition factor including purely technical risk, organizational elements and regulatory elements. The second is the social risk recognition factor including economical and mental elements. The last is the communication factor including the influence of mass media, difficulty in frank communication in local community etc. It became clear that the information provision activities conducted by the government and the nuclear industry were lack of in-depth understanding of actual information needs in the public. Provision of information contents consistent with our observations is recommended for reestablishment of public trust in expert and for more informative dialogical interactions. (author)

  6. Application of stable adaptive schemes to nuclear reactor systems, (1)

    International Nuclear Information System (INIS)

    Fukuda, Toshio

    1978-01-01

    Parameter identification and adaptive control schemes are presented for a point reactor with internal feedbacks which lead to the nonlinearity of the overall system. Both are shown stable with new representation of the system, which corresponds to the nonminimal system representation, in the vein of the Model Reference Adaptive System (MRAS) via the Lyapunov's method. For the sake of the parameter identification, model parameters can be adjusted adaptively as soon as measurements start, while plant parameters can also adaptively be compensated through control input to reduce the output error between the model and the plant for the case of the adaptive control. In the case of the adaptive control, control schemes are presented for two cases, the case of the unknown decay constant of the delayed neutron and the case of the known constant. The adaptive control scheme for the latter case is shown extremely simpler than that for the former. Furthermore, when plant parameters vary slowly with time, computer simulations show that the proposed adaptive control scheme works satisfactorily enough to stabilize an unstable reactor and that it does even in the noise with small variance. (auth.)

  7. Nuclear decay data for radionuclides occurring in routine releases from nuclear fuel cycle facilities

    International Nuclear Information System (INIS)

    Kocher, D.C.

    1977-08-01

    This report gives tabulations of the atomic and nuclear radiations emitted by 240 radionuclides. Most of the radionuclides are those expected to occur in routine releases of effluents from nuclear fuel cycle facilities. For each radionuclide are given the half-life and recommended values for the energies, intensities, and equilibrium absorbed-dose constants for each of the atomic and nuclear radiations. Also given are the daughter radionuclides produced and recommended values for decay branching ratios, where applicable. The radioactivity decay chains and branching ratios are displayed in diagram form

  8. Nuclear decay data for radionuclides occurring in routine releases from nuclear fuel cycle facilities

    Energy Technology Data Exchange (ETDEWEB)

    Kocher, D.C.

    1977-08-01

    This report gives tabulations of the atomic and nuclear radiations emitted by 240 radionuclides. Most of the radionuclides are those expected to occur in routine releases of effluents from nuclear fuel cycle facilities. For each radionuclide are given the half-life and recommended values for the energies, intensities, and equilibrium absorbed-dose constants for each of the atomic and nuclear radiations. Also given are the daughter radionuclides produced and recommended values for decay branching ratios, where applicable. The radioactivity decay chains and branching ratios are displayed in diagram form.

  9. Nuclear structure and decay data evaluation in Europe

    Science.gov (United States)

    Negret, Alexandru; Balabanski, Dimiter; Dimitriou, Paraskevi; Elekes, Zoltan; Mertzimekis, Theo J.; Pascu, Sorin; Timar, Janos

    2017-09-01

    Nuclear Structure and Decay Data (NSDD) activities in Europe include mass-chain and individual nuclei evaluations as well as horizontal evaluations and compilations, data dissemination and educational activities. As such they are essential for a large range of applications from energy, environmental, and medical to basic research in nuclear structure and reactions, all of which are intensively pursued in Europe. Although the NSDD evaluation groups in Europe form part of the international network of NSDD evaluators, which is coordinated by the International Atomic Energy Agency, they are faced with some very distinct challenges. We shortly present the NSDD Data Centre at IFIN-HH, Bucharest and discuss possible actions to improve the situation for the entire European NSDD evaluation effort.

  10. Nuclear structure and decay data evaluation in Europe

    Directory of Open Access Journals (Sweden)

    Negret Alexandru

    2017-01-01

    Full Text Available Nuclear Structure and Decay Data (NSDD activities in Europe include mass-chain and individual nuclei evaluations as well as horizontal evaluations and compilations, data dissemination and educational activities. As such they are essential for a large range of applications from energy, environmental, and medical to basic research in nuclear structure and reactions, all of which are intensively pursued in Europe. Although the NSDD evaluation groups in Europe form part of the international network of NSDD evaluators, which is coordinated by the International Atomic Energy Agency, they are faced with some very distinct challenges. We shortly present the NSDD Data Centre at IFIN-HH, Bucharest and discuss possible actions to improve the situation for the entire European NSDD evaluation effort.

  11. Nuclear structure from radioactive decay: Annual progress report

    International Nuclear Information System (INIS)

    Wood, J.L.

    1987-01-01

    The primary focus this year has been studies of intruder states and shape coexistence in the neutron-deficient Z ∼ 82 region. Most notably, the existence and conditions for the occurrence of electric monopole (E0) transitions have been considerably clarified. This has been a topic of considerable confusion. On-line decay scheme spectroscopy of mass-separated isotopes at UNISOR (in a collaboration with LSU) has now completely resolved all points of disagreement. These studies are part of a larger program directed towards building a complete picture of shape coexistence. It is becoming evident that E0 transitions are a key signature to shape coexistence. Thus, their correct identification and location are crucial

  12. Decay of 132Cs and nuclear structure of 132Xe

    International Nuclear Information System (INIS)

    Cruz, M.T.F. da; Goldman, I.D.

    1989-02-01

    Gamma spectroscopy, coincidence and angular correlation experiments were performed, in an extensive study of 132 Cs decay. The population intensities of states in 132 Ba were measured, some upper limits were determined and the value of the transition to the 4 1 + state of 132 Ba has drastically changed. A new gamma transition of 688 KeV was detected and located in the level scheme of 132 Xe. The angular correlation measurements were performed with a Ge(Li)-NaI(Tl) spectrometer and helped in choosing the spin value for the 1804 KeV state of 132 Xe. Kumar-Baranger-type calculations were performed for the 132 Xe fairly good results. The resulting potential energy surface for 132 Xe is very different from that of Gneuss and Greiner model, suggesting the need for any quadrupole moment measurement for this nucleus. (author) [pt

  13. Novel scheme for making cheap electricity with nuclear energy

    International Nuclear Information System (INIS)

    Pettibone, J.A.

    1979-01-01

    Nuclear fuels should produce cheaper electricity than coal, considering their high specific energy and low cost. To exploit these properties, the scheme proposed here replaces the expensive reactor/steam-turbine system with an engine in which the expansion of a gas heated by a nuclear explosion raises a mass of liquid, thereby producing stored hydraulic energy. This energy could be converted to electricity by hydroelectric generation with water as the working fluid or by magnetohydrodynamic (MHD) generation with molten metal. A rough cost analysis suggests the hydroelectric system could reduce the present cost of electricity by two-thirds, and the MHD system by even more. Such cheap power would make feasible large-scale electrolysis to produce hydrogen and other fuels and chemical raw materials

  14. Nuclear parameters determination of the 127Te β - decay: a proposal for teaching nuclear physics

    International Nuclear Information System (INIS)

    Batista, Wagner Fonseca

    2011-01-01

    A study of the 127 Te β - decay was carried out by means of gamma spectroscopy measurements using high resolution HPGe detector, in the region from 30 keV to 1.0 MeV, aiming to get a better understanding of the 127 Te nuclear structure. The radioactive sources of 12 7Te were obtained from the 126 Te(n,γ) 1 '2 7 Te nuclear reaction produced in the IEA- R1 nuclear reactor at IPEN/CNEN-SP. Five gamma t ransitions previously attributed to this decay were confirmed with a better precision than previously. The half-life of 127 Te was also studied resulting in data with lower uncertainty. Using a set of data selected from gamma spectroscopy measurements was developed and applied a didactic proposal for high school students using the Excel software. (author)

  15. Neutrino induced decoherence and variation in nuclear decay rates

    International Nuclear Information System (INIS)

    Singleton, Douglas; Inan, Nader; Chiao, Raymond Y.

    2015-01-01

    Recent work has proposed that the interaction between ordinary matter and a stochastic gravitational background can lead to the decoherence of large aggregates of ordinary matter. In this work we point out that these arguments can be carried over to a stochastic neutrino background but with the Planck scale of the gravitational decoherence replaced by the weak scale. This implies that it might be possible to observe such neutrino induced decoherence on a small, microscopic system rather than a macroscopic system as is the case for gravitationally induced decoherence. In particular we suggest that neutrino decoherence could be linked with observed variations in the decay rates of certain nuclei. Finally we point out that this proposed neutrino induced decoherence can be considered the complement of the Mikheev–Smirnov–Wolfenstein (MSW) effect. - Highlights: • Review of decoherence arguments for matter moving in a stochastic gravitational background. • Application of these decoherence arguments to neutrinos and the weak interaction scale. • Suggestions of a connection between neutrino decoherence and variable nuclear decay rates. • Connection of neutron decoherence as the inverse of the MSW effect

  16. Performance demonstration of 4πβ(LS)-γ coincidence counting system for standardization of radionuclides with complex decay scheme.

    Science.gov (United States)

    Kulkarni, D B; Anuradha, R; Joseph, Leena; Kulkarni, M S; Tomar, B S

    2016-02-01

    A standardization of (134)Cs and (131)I was carried out in order to demonstrate the performance and applicability of the 4πβ(LS)-γ coincidence counting system for standardization of radionuclides with complex decay scheme. The coincidence analyzer, capable of analyzing coincidence between beta and two gamma windows simultaneously, was developed and used for the standardization. The use of this dual coincidence analyzer has reduced the total experimental time by half. The activity concentrations obtained using the 4πβ(LS)-γ coincidence counting system, a 4πβ(PC)-γ coincidence counting system, and the CIEMAT/NIST method are in excellent agreement with each other within uncertainty limits and hence demonstrates its performance for standardization of radionuclides decaying with complex decay scheme. Hence use of this 4πβ(LS)-γ coincidence counting system can be an alternative method suitable to standardize radionuclides with complex decay scheme with acceptable precision. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Radiative decays of ground-state qq-bar mesons in the U-tilde(12)-classification scheme of hadrons

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, Tomohito; Yamada, Kenji [Nihon University, Funabashi (Japan). Junior College Funabashi Campus. Dept.of Engineering Science; Oda, Masuho [Kokushikan University, Tokyo (Japan). Faculty of Engineering; Ishida, Shin [Nihon University, Tokyo (Japan). College of Science and Technology. Research Institute of Science and Technology

    2005-07-01

    The radiative transitions between ground-states of light qq-bar mesons are investigated in the U-tilde(12)-classification scheme. In this scheme the rich decay-spectra are offered even in transition between ground states due to the appearance of 'chiral states', out of the framework of non-relativistic quark model (NRQM) based on the SU(6)-symmetry, and it is shown that these states play an important role to improve our previous results, obtained without considering them. (author)

  18. Co-ordination of the international network of nuclear structure and decay data evaluators

    International Nuclear Information System (INIS)

    Schmidt, J.J.

    1988-10-01

    The IAEA Nuclear Data Section convened the eighth meeting of the international nuclear structure and decay data network at Ghent, Belgium, 16-20 May 1988. The meeting was attended by 21 scientists from 12 Member States and three international organizations, concerned with the compilation, evaluation, and dissemination of nuclear structure and decay data. This document contains a summary of the meeting, the proceedings of the meeting and in appendices status reports of activities in nuclear structure and decay data from the participating centers. Refs and tabs

  19. Co-ordination of the international network of nuclear structure and decay data evaluation

    International Nuclear Information System (INIS)

    Lemmel, H.D.

    1991-11-01

    The IAEA Nuclear Data Section convened the ninth meeting of the international nuclear structure and decay data network at Kuwait, 10-14 March 1990. The meeting was attended by 19 scientists from 9 Member States and two international organizations, concerned with the compilation, evaluation, and dissemination of nuclear structure and decay data. The document contains a summary and the proceedings of the meeting, and in annexes, status reports of activities in nuclear structure and decay data from the participating centers. A separate abstract was prepared for one of the scientific lectures related to the topics of the meeting which is reproduced in full length. Refs, figs and tabs

  20. Method and program for decay scheme reconstruction based on formal logical analysis of gamma-gamma coincidence matrix

    International Nuclear Information System (INIS)

    Adam, J.; Tsupko-Sitnikov, V.M.

    1996-01-01

    A new, rigorously substantiated approach to construction of decay schemes on the basis of γ-γ coincidence data is described. Complete decay modes (concrete cascades of transitions from excited to the ground-state of a nucleus excited in a decay or a reaction) and continuity regions in complete modes (regions of successive transitions) are isolated by logical operations with rows (columns) of a symmetrical coincidence matrix where rows (columns) correspond to energies of coinciding transitions and matrix elements are unities and zeros, depending on the presence or absence of the given coincidence. To reject false complete modes and continuity regions arising from incompleteness of the coincidence data and errors in them, energy selection is introduced for complete modes and continuity regions, which demands that total energy of their constituent transitions should be equal to total energy of some other complete modes and continuity regions and to the energies of singles. With the continuity regions found, it is possible to order transitions in the selected complete modes and to algorithmize matching of complete modes into a decay scheme. 10 refs., 3 figs

  1. The human nuclear poly(a-binding protein promotes RNA hyperadenylation and decay.

    Directory of Open Access Journals (Sweden)

    Stefan M Bresson

    Full Text Available Control of nuclear RNA stability is essential for proper gene expression, but the mechanisms governing RNA degradation in mammalian nuclei are poorly defined. In this study, we uncover a mammalian RNA decay pathway that depends on the nuclear poly(A-binding protein (PABPN1, the poly(A polymerases (PAPs, PAPα and PAPγ, and the exosome subunits RRP6 and DIS3. Using a targeted knockdown approach and nuclear RNA reporters, we show that PABPN1 and PAPα, redundantly with PAPγ, generate hyperadenylated decay substrates that are recognized by the exosome and degraded. Poly(A tail extension appears to be necessary for decay, as cordycepin treatment or point mutations in the PAP-stimulating domain of PABPN1 leads to the accumulation of stable transcripts with shorter poly(A tails than controls. Mechanistically, these data suggest that PABPN1-dependent promotion of PAP activity can stimulate nuclear RNA decay. Importantly, efficiently exported RNAs are unaffected by this decay pathway, supporting an mRNA quality control function for this pathway. Finally, analyses of both bulk poly(A tails and specific endogenous transcripts reveals that a subset of nuclear RNAs are hyperadenylated in a PABPN1-dependent fashion, and this hyperadenylation can be either uncoupled or coupled with decay. Our results highlight a complex relationship between PABPN1, PAPα/γ, and nuclear RNA decay, and we suggest that these activities may play broader roles in the regulation of human gene expression.

  2. New physics searches in nuclear and neutron $\\beta$ decay arXiv

    CERN Document Server

    Gonzalez-Alonso, Martin; Severijns, Nathal

    The status of tests of the standard electroweak model and of searches for new physics in allowed nuclear $\\beta$ decay and neutron decay is reviewed including both theoretical and experimental developments. The sensitivity and complementarity of recent and ongoing experiments are discussed with emphasis on their potential to look for new physics. Measurements are interpreted using a model-independent effective field theory approach enabling to recast the outcome of the analysis in many specific new physics models. Special attention is given to the connection that this approach establishes with high-energy physics. A new global fit of available $\\beta$-decay data is performed incorporating, for the first time in a consistent way, superallowed $0^+\\to 0^+$ transitions, neutron decay and nuclear decays. The constraints on exotic scalar and tensor couplings involving left- or right-handed neutrinos are determined while a constraint on the pseudoscalar coupling from neutron decay data is obtained for the first tim...

  3. Symmetry violations in nuclear and neutron beta decay

    NARCIS (Netherlands)

    Vos, K. K.; Wilschut, H. W.; Timmermans, R. G. E.

    2015-01-01

    The role of beta decay as a low-energy probe of physics beyond the standard model is reviewed. Traditional searches for deviations from the standard model structure of the weak interaction in beta decay are discussed in light of constraints from the Large Hadron Collider and the neutrino mass.

  4. A novel power amplification scheme for nuclear magnetic resonance/nuclear quadrupole resonance systems

    Science.gov (United States)

    Zhang, Xinwang; Schemm, Nathan; Balkır, Sina

    2011-03-01

    Nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR)-based chemical analysis systems have been widely utilized in various areas such as medicine, security, and academic research. In these applications, the power amplifier stage plays a key role in generating the required oscillating magnetic fields within a radio frequency coil that serves as the probe. However, the bulky size and relatively low efficiency of the traditional power amplification schemes employed present a bottleneck for the realization of compact sized and portable NMR and NQR systems. To address this problem, this work presents a class D voltage-switching power amplification scheme with novel fast-start and fast-stop functions that are suitable for generating ideal NMR and NQR excitation signals. Compared to the traditional analog power amplifiers (PAs), the proposed switched-mode PA can achieve significant improvement on the power efficiency as well as the physical volume. A PA circuit for portable NQR-based explosive detection systems has been designed and built using the proposed scheme with 1 kW possible maximum output power and 10 MHz maximum operating frequency. Test results show that the presented PA achieves more than 60% measured efficiency within a highly compact volume while sustaining fast start and stop of excitation signals in the order of microseconds.

  5. Isotensor Axial Polarizability and Lattice QCD Input for Nuclear Double-β Decay Phenomenology

    Science.gov (United States)

    Shanahan, Phiala E.; Tiburzi, Brian C.; Wagman, Michael L.; Winter, Frank; Chang, Emmanuel; Davoudi, Zohreh; Detmold, William; Orginos, Kostas; Savage, Martin J.; Nplqcd Collaboration

    2017-08-01

    The potential importance of short-distance nuclear effects in double-β decay is assessed using a lattice QCD calculation of the n n →p p transition and effective field theory methods. At the unphysical quark masses used in the numerical computation, these effects, encoded in the isotensor axial polarizability, are found to be of similar magnitude to the nuclear modification of the single axial current, which phenomenologically is the quenching of the axial charge used in nuclear many-body calculations. This finding suggests that nuclear models for neutrinoful and neutrinoless double-β decays should incorporate this previously neglected contribution if they are to provide reliable guidance for next-generation neutrinoless double-β decay searches. The prospects of constraining the isotensor axial polarizabilities of nuclei using lattice QCD input into nuclear many-body calculations are discussed.

  6. Decay scheme of the U{sup 2}35; Esquema de desintegracion del U-235

    Energy Technology Data Exchange (ETDEWEB)

    Gaeta, R.

    1965-07-01

    A study of the Th{sup 2}31 excited levels from the alpha decay of the U{sup 2}35, is carried out. The alpha particle spectrum was measured by means of a semiconductor counter spectrometer with an effective resolution of 18 keV. Nineteen new lines were identified. The gamma-ray spectrum was measured with thin samples of U{sup 2}35, free from decay products, and in such geometrical conditions, that most of the interference effects were eliminated. The gamma-gamma coincidence spectra have made easier a better knowledge of the transition between the several levels. (Author) 110 refs.

  7. Applications of Rajeval technique for the evaluation of discrepant nuclear decay data

    International Nuclear Information System (INIS)

    Rajput, M.U.

    2006-11-01

    There are 4 levels 95NB below the decay energy in the Adopted Levels of the 93 micro 08 evaluation that are not reported in this decay scheme: these are 730 6 (5/2+), 799 5 (3/2), 1011 8 (5/2), and 1088keV. These levels have only been reported in reaction studies and their lemma decay modes are not known the 730 level would be fed fed by and allowed beta decay, so this evaluator suggests it is actually the 724 level and the J* assignment is incorrect. The failure to observe decays to the possible 799 and 1011 levels is surprising since these would be 1st forbidden decays and from beta decay systematics (73Ra10) could have branches of several percent. Therefore, one must rely on the fact that other lemda rays have not been reported to support the completeness of this scheme. If one leaves the values of 65F102 in the data set, it is desirable to use either the RAJEVAL or Normalized Residual method to treat this discrepancy. The RAJEVAL method increase the uncertainty for the 65F102 value from 0.2 to 0.88 and gives the resulting value of 64.032(6) while the Normalized Residual method increase this uncertainty to 0.58 and give a result of 64.032(6). So, the adopted value is the same for each of these three methods. (author)

  8. Double beta decays and related subjects for particle and nuclear physics

    International Nuclear Information System (INIS)

    Ejiri, Hiroyasu

    1991-01-01

    Present status and some perspectives in 1990's are briefly given on double beta decays and related subjects. Subjects discussed are as follows I) Double beta decays without neutrinos, which require lepton number non-conservations and finite neutrino mass. II) Double beta decays followed by two neutrinos. III) Double weak processes with strangeness change ΔS = 2, leading to the H particle with 6 quarks of ss uu dd. IV) Charge non-conservation and electron decays. These are very rare nuclear processes studied by Ultra RAre-process NUclear Spectroscopy (URANUS). It is shown that URANUS is an important detector frontier of non-accelerator nuclear physics in 1990's. (orig.)

  9. MEASUREMENT OF THE CP-VIOLATION PARAMETER THE ABSOLUTE VALUE OF ETA SUB oo IN K(sub L) MESON DECAYS TO 2 NEUTRAL PIONS DECAY.

    Science.gov (United States)

    GRAAFF GENERATORS , MATRICES(MATHEMATICS), MONTE CARLO METHOD, TABLES(DATA), THESES...DECAY SCHEMES, *K MESONS), PIONS, MUONS, PROTONS, GAMMA RAYS, NUCLEAR SPINS, PARITY, INTERACTIONS, BETA DECAY, SPECTROMETERS, SYNCHROTRONS, VAN DE

  10. Coordination of the international network of nuclear structure and decay data evaluators

    International Nuclear Information System (INIS)

    Lorenz, A.

    1984-09-01

    This meeting of the International NSDD (Nuclear Structure and Decay Data) Network dealt with problems related to both the coordination of the NSDD network of centres and groups and to physics questions related to the evaluation of NSDD. The status of the mass-chain and nuclear structure data is reviewed and the planned activities are presented

  11. Co-ordination of the International Network of Nuclear Structure and Decay Data Evaluators

    Energy Technology Data Exchange (ETDEWEB)

    Ricard-McCutchan, E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Dimitriou, P. [Intl Atomic Energy Agency (IAEA), Vienna (Austria); Nichols, A. L. [Univ. of Surrey, Guildford (United Kingdom)

    2015-08-01

    The 21st meeting of the International Network of Nuclear Structure and Decay Data Evaluators was convened at the IAEA Headquarters, Vienna, from 20 to 24 April 2015 under the auspices of the IAEA Nuclear Data Section. This meeting was attended by 36 scientists from 15 Member States, plus IAEA staff, concerned with the compilation, evaluation and dissemination of nuclear structure and decay data. A summary of the meeting, data centre reports, various proposals considered, and actions agreed by the participants, as well as recommendations/conclusions are presented within this document.

  12. IAEA advisory group meeting on nuclear structure and decay data, Zeist, The Netherlands, 11-14 May 1982

    International Nuclear Information System (INIS)

    Lorenz, A.

    1982-08-01

    The IAEA Nuclear Data Section convened the fifth meeting of the international nuclear structure and decay data network at Zeist near Utrecht, in The Netherlands, 11-14 May 1982. The meeting was attended by 24 scientists from 11 Member States and 2 international organizations, concerned with the compilation, evaluation, and dissemination of nuclear structure and decay data. (author)

  13. IAEA advisory group meeting on nuclear structure and decay data. IAEA, Vienna 21-25 April 1980

    International Nuclear Information System (INIS)

    Lorenz, A.

    1980-10-01

    The IAEA Nuclear Data Section convened the fourth meeting of the international nuclear structure and decay data network at IAEA Headquarters in Vienna, Austria, from 21-25 April 1980. The meeting was attended by 23 Scientists from 11 Member States and 2 international organizations, concerned with the compilation, evaluation, and dissemination of nuclear structure and decay data. (author)

  14. Nuclear Reactor Component Code CUPID-I: Numerical Scheme and Preliminary Assessment Results

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Hyoung Kyu; Jeong, Jae Jun; Park, Ik Kyu; Kim, Jong Tae; Yoon, Han Young

    2007-12-15

    A component scale thermal hydraulic analysis code, CUPID (Component Unstructured Program for Interfacial Dynamics), is being developed for the analysis of components of a nuclear reactor, such as reactor vessel, steam generator, containment, etc. It adopted three-dimensional, transient, two phase and three-field model. In order to develop the numerical schemes for the three-field model, various numerical schemes have been examined including the SMAC, semi-implicit ICE, SIMPLE, Row Scheme and so on. Among them, the ICE scheme for the three-field model was presented in the present report. The CUPID code is utilizing unstructured mesh for the simulation of complicated geometries of the nuclear reactor components. The conventional ICE scheme that was applied to RELAP5 and COBRA-TF, therefore, were modified for the application to the unstructured mesh. Preliminary calculations for the unstructured semi-implicit ICE scheme have been conducted for a verification of the numerical method from a qualitative point of view. The preliminary calculation results showed that the present numerical scheme is robust and efficient for the prediction of phase changes and flow transitions due to a boiling and a flashing. These calculation results also showed the strong coupling between the pressure and void fraction changes. Thus, it is believed that the semi-implicit ICE scheme can be utilized for transient two-phase flows in a component of a nuclear reactor.

  15. Nuclear Reactor Component Code CUPID-I: Numerical Scheme and Preliminary Assessment Results

    International Nuclear Information System (INIS)

    Cho, Hyoung Kyu; Jeong, Jae Jun; Park, Ik Kyu; Kim, Jong Tae; Yoon, Han Young

    2007-12-01

    A component scale thermal hydraulic analysis code, CUPID (Component Unstructured Program for Interfacial Dynamics), is being developed for the analysis of components of a nuclear reactor, such as reactor vessel, steam generator, containment, etc. It adopted three-dimensional, transient, two phase and three-field model. In order to develop the numerical schemes for the three-field model, various numerical schemes have been examined including the SMAC, semi-implicit ICE, SIMPLE, Row Scheme and so on. Among them, the ICE scheme for the three-field model was presented in the present report. The CUPID code is utilizing unstructured mesh for the simulation of complicated geometries of the nuclear reactor components. The conventional ICE scheme that was applied to RELAP5 and COBRA-TF, therefore, were modified for the application to the unstructured mesh. Preliminary calculations for the unstructured semi-implicit ICE scheme have been conducted for a verification of the numerical method from a qualitative point of view. The preliminary calculation results showed that the present numerical scheme is robust and efficient for the prediction of phase changes and flow transitions due to a boiling and a flashing. These calculation results also showed the strong coupling between the pressure and void fraction changes. Thus, it is believed that the semi-implicit ICE scheme can be utilized for transient two-phase flows in a component of a nuclear reactor

  16. Nuclear β decay with a massive neutrino in an external electromagnetic field

    International Nuclear Information System (INIS)

    Ternov, I.M.; Rodionov, V.N.; Zhulego, V.G.; Lobanov, A.E.; Pavlova, O.S.; Dorofeev, O.F.

    1986-01-01

    Beta decay in the presence of an external electromagnetic field is investigated, taking into account the non-zero neutrino rest mass. The spectrum of electrons and polarisation effects of different orientations of nuclear spin are considered. It is shown that the electromagnetic wave substantially modifies the boundaries of the spectrum of β electrons. The results, which include an analysis of the total decay probability in intense magnetic fields, may have various astrophysical implications. (author)

  17. ZZ NUCDECAYCALC, Nuclear Decay Data for Radiation Dosimetry Calculation for ICRP

    International Nuclear Information System (INIS)

    2002-01-01

    1 - Description or function: The Dosimetry Research Group (DRG) of the Health Sciences Research Division at ORNL has for several years maintained data bases of nuclear decay data for use in dosimetric calculations. The data on mean and unique energy plus intensity have been previously published, in abridged form, in Publication 38 of the International Commission on Radiological Protection (ICRP 1983). This data base was designed to address the needs in medical, environmental, and occupational radiation protection. DLC-172/NUCDECAY is required by the CCC-620/SEECAL program to calculate age-dependent specific effective energies. 2 - Methods: The unabridged data used in preparing ICRP Publication 38 are distributed in electronic form in this package. The collection consists of data on the energies and intensities of radiations emitted by the 825 radionuclides reported, although abridged, in ICRP Publication 38 plus an additional 13 radionuclides evaluated during preparation of a monograph for the Medical Internal Radiation Dose (MIRD) Committee of the Society of Nuclear Medicine. Each collection is contained in an ASCII file (INDEXR.DAT) which is a sorted list of the radionuclides containing the decay chain information. The utility code DecayCalc extracts the decay data from the library for radionuclide(s) specified by the user. It computes the activities of radionuclides present after decay and ingrowth over a user-specified time period from 1 minute to 50 years. Decay data for any decay chain may be displayed and printed either in tabular form or graphically. DecayCalc, in a slightly modified version, will be a part of CCC-553/Rascal v3. DecayCalc is a Windows application that runs under Microsoft Windows 95 or 98, or Microsoft Windows NT 4.0 or later. The Compac Fortran 77 compiler was used to compile the code. The full source for DecayCalc is not provided but will be distributed when Rascal V3 is released

  18. Signature scheme for the microscopic description of nuclear collective excitations

    International Nuclear Information System (INIS)

    Ogawa, K.

    1980-04-01

    The symmetries between the proton and neutron systems in a nucleus are described in terms of the signatures. Three kinds of signatures (i.e. the pn-, p anti n- and p anti p- (or n anti n-) signatures) are introduced and they are related to the appearance of various collective motions such as rotations or vibrations. It is shown that the pn-signature scheme provides a band-like structure of deformed nuclei, while the features associated with the quadrupole vibration are obtained in the p anti n- and p anti p-signature scheme. From the detail investigation of the p anti n-symmetric wave functions, it is concluded that the reguralities provided by the present shell model are more analogous to those of the γ-unstable surface vibration model (Wilets-Jean model) than to those of harmonic phonon model. (author)

  19. NuDat 2.0: Nuclear Structure and Decay Data on the Internet

    International Nuclear Information System (INIS)

    Sonzogni, A.A.

    2005-01-01

    NuDat 2.0 is a software product developed by the National Nuclear Data Center. It provides an interface between web users and several NNDC nuclear structure and decay databases. NuDat 2.0 can be used to search for ground and excited states level properties, gamma-ray information, and decay radiation information. In addition to the search capabilities, an interactive chart of nuclei is displayed. Different examples highlighting NuDat 2 search capabilities and display options are presented

  20. Recent status of the studies of nuclear masses and {beta}-decay

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Masami [Waseda Univ., Tokyo (Japan). Advanced Research Center for Science and Engineering

    1996-05-01

    The recent status of the above studies was explained, especially, nuclear masses were described from the aspect of probability theory and that of {beta}-decay suggested that the first forbidden transition was hindered between the ground states. We have to study various systematics in order to know the mass surface, Way-Yamada-Matumoto type systematics is better to check the experimental nuclear masses. The gross theory is very useful to understand the general aspect of {beta}-decay. The understanding method of mass surface, systematic check of mass and hindrance of the first forbidden transition at rank 1 were explained. (S.Y.)

  1. Development of Cyber Security Scheme for Nuclear Power Plant

    International Nuclear Information System (INIS)

    Hong, S. B.; Choi, Y. S.; Cho, J. W.

    2009-12-01

    Nuclear I and C system is considered to be safe on the cyber threat because of the use of exclusive communication network and operating system. But the trend of open architecture and standardization on the equipment of I and C system, it is not safe on the cyber threat such as hacking and cyber terror. It is needed to protect nuclear I and C systems by the cyber attack, Countermeasures of the cyber security is required a lot of time and endeavors because there are many factors on the environment of cyber security and cyber attack. For the nuclear cyber security, we should make structural framework and eliminate cyber vulnerabilities by the analysis of cyber environment. The framework for the cyber security includes planning, embodiment of security technologies, security audit, security management and security maintenance. In this report, we examined IT security technology and the trend of standard in the industrial I and C system, and proposed a method to construct cyber security for the nuclear power plant. We analysed the threat of cyber security, vulnerability and cyber risk, then we present a method for the cyber security structure and the countermeasures

  2. Phase-space exploration in nuclear giant resonance decay

    International Nuclear Information System (INIS)

    Drozdz, S.; Nishizaki, S.; Wambach, J.; Speth, J.

    1995-01-01

    The rate of phase-space exploration in the decay of isovector and isoscalar giant quadrupole resonances in 40 Ca is analyzed. The study is based on the time dependence of the survival probability and of the spectrum of generalized entropies evaluated in the space of one-particle--one-hole (1p-1h) and 2p-2h states. Three different cases for the level distribution of 2p-2h background states, corresponding to (a) high degeneracy, (b) classically regular motion, and (c) classically chaotic motion, are studied. In the latter case the isovector excitation evolves almost statistically while the isoscalar excitation remains largely localized, even though it penetrates the whole available phase space

  3. Very hot nuclear systems and their binary and multifragment decay

    Energy Technology Data Exchange (ETDEWEB)

    Moretto, L.G.; Blumenfeld, Y.; Delis, D.; Wozniak, G.J.

    1990-10-01

    Compound emission of complex fragments in the reaction {sup 63}Cu + {sup 12}C is used to determine the associated ridge-line potential. Compound binary emission of complex fragments at higher energies is illustrated for a variety of reactions. Complex fragment emission from 18, 26, 31, 35, 45 and 55 MeV/N {sup 139}La/{sup 129}Xe + {sup 12}C, {sup 27}Al, {sup 40}Ca, {sup 51}V, {sup nat}Cu and {sup 139}La reactions has been studied. Multifragment events from these reactions were assigned to sources characterized by their energy and mass through the incomplete-fusion-model kinematics. Excitation functions for the various multifragment channels appear to be nearly independent of the system and bombarding energy. Preliminary comparisons of the data with sequential-statistical-decay calculations are discussed. 16 refs., 9 figs.

  4. Studies on cluster decay from trans-lead nuclei using different versions of nuclear potentials

    Energy Technology Data Exchange (ETDEWEB)

    Santhosh, K.P.; Sukumaran, Indu [Kannur University, School of Pure and Applied Physics, Payyanur, Kerala (India)

    2017-06-15

    The cluster decays from various isotopes of trans-lead nuclei have been studied using 12 different nuclear potentials by evaluating decay half-lives and are then compared with the available experimental data. The study has shown that the barrier penetrability as well as the decay half-lives varies with the nuclear potential used. The standard deviation of the estimated half-lives is also calculated for these twelve nuclear potentials in comparison with the experimental data. The potential Bass 1980 is found to be the most appropriate potential for studying cluster radioactivity as the standard deviation obtained is least. Among the different proximity potential versions; proximity 1977, proximity 1988, proximity 2000, and modified proximity 2000, the minimum standard deviation is for proximity 1988. The Geiger-Nuttall (G-N) plots studied for different cluster emissions from various parents are observed to show linear behavior but with different slopes and intercepts. Again, the G-N plots obtained are linear with different slopes and intercepts when plotted for different nuclear potentials. So it is observed that with the inclusion of different nuclear potentials, the linearity of the G-N plot remains unaltered. Irrespective of the nuclear potential used, the universal curve (log{sub 10}T{sub 1/2} vs. -ln P) studied for various clusters emitted from various parents are obtained as linear with same slope and intercept. (orig.)

  5. Chemical Plant Accidents in a Nuclear Hydrogen Generation Scheme

    International Nuclear Information System (INIS)

    Brown, Nicholas R.; Revankar, Shripad T.

    2011-01-01

    A high temperature nuclear reactor (HTR) could be used to drive a steam reformation plant, a coal gasification facility, an electrolysis plant, or a thermochemical hydrogen production cycle. Most thermochemical cycles are purely thermodynamic, and thus achieve high thermodynamic efficiency. HTRs produce large amounts of heat at high temperature (1100 K). Helium-cooled HTRs have many passive, or inherent, safety characteristics. This inherent safety is due to the high design basis limit of the maximum fuel temperature. Due to the severity of a potential release, containment of fission products is the single most important safety issue in any nuclear reactor facility. A HTR coupled to a chemical plant presents a complex system, due primarily to the interactive nature of both plants. Since the chemical plant acts as the heat sink for the nuclear reactor, it important to understand the interaction and feedback between the two systems. Process heat plants and HTRs are generally very different. Some of the major differences include: time constants of plants, safety standards, failure probability, and transient response. While both the chemical plant and the HTR are at advanced stages of testing individually, no serious effort has been made to understand the operation of the integrated system, especially during accident events that are initiated in the chemical plant. There is a significant lack of knowledge base regarding scaling and system integration for large scale process heat plants coupled to HTRs. Consideration of feedback between the two plants during time-dependent scenarios is absent from literature. Additionally, no conceptual studies of the accidents that could occur in either plant and impact the entire coupled system are present in literature

  6. Nuclear transmutation of actinides other than fuel as a radioactive waste management scheme

    International Nuclear Information System (INIS)

    Cecille, L.; Hage, W.; Hettinger, H.; Mannone, F.; Mousty, F.; Schmidt, E.; Sola, A.; Huber, B.; Koch, L.

    1977-01-01

    The bulk of fission products in the high-level waste (HLW) decays to innocuous hazard levels within about 600 years. Actinide waste and a few fission products however represent a potential risk up to some hundreds of thousand of years. An alternative to the disposal of the whole HLW in geological formations is its fractionation, a nuclear transmutation of long-lived isotopes in fission reactors and a geological disposal of the other components. This solution would decrease the potential long-term risks of the geological waste disposal and would also accomodate to the demand of public opinion. The results of studies related to this management scheme are outlined with special reference to areas, where additional effort is required for realistic cost/benefit evaluations. Reactor physics calculations demonstrated the feasibility of actinide incineration in thermal and fast reactors. Obtained transmutation rates are sufficiently high to garantee acceptably small actinide inventories in the reactor in the case of self-generated actinide recycling. It appears that fast breeders could be used as transmutation devices without major additional reactor devlopment work. The thermal power rating of actinide fuel elements and the contribution of actinides and of minor amounts of lanthanide impurities to the neutron economy of the reactor has been evaluated. Sensitivity studies indicated that the results are dependent on the reactor operation mode and on the accuracy of the nuclear data. These calculations permitted the identification of isotopes for which cross section masurements and improved theoretical methods are required. The chemical separation of actinides from the HLW with the envisaged decontamination factors is being studied by solvent extraction and precipitation techniques using waste simulates and samples of high activity waste from European reprocessing plants. Up to now, the obtained results do not yet allow a definitive judgement on the feasibility of actinides

  7. Workshop on nuclear structure and decay data: Theory and evaluation, 2008

    International Nuclear Information System (INIS)

    Nichols, A.L.; McLaughlin, P.K.

    2008-06-01

    A two-week Workshop on Nuclear Structure and Decay Data under the auspices of the IAEA Nuclear Data Section was organised and held at the Abdus Salam International Centre for Theoretical Physics (ICTP) in Trieste, Italy from 28 April to 9 May 2008. This workshop constituted a further development of previous Nuclear Structure and Decay Data Workshops held in 2002, 2003, 2005 and 2006. The aims and contents of the 2008 workshop are summarized, along with the agenda, list of participants, comments and recommendations. All recent workshop material has been assembled in this INDC report, and is also freely available on CD-ROM (all relevant PowerPoint presentations and manuals along with appropriate computer codes). (author)

  8. Study of Nuclear Decay Data Contribution to Uncertainties in Heat Load Estimations for Spent Fuel Pools

    Science.gov (United States)

    Ferroukhi, H.; Leray, O.; Hursin, M.; Vasiliev, A.; Perret, G.; Pautz, A.

    2014-04-01

    At the Paul Scherrer Institut (PSI), a methodology for nuclear data uncertainty propagation in CASMO-5M (C5M) assembly calculations is under development. This paper presents a preliminary application of this methodology to C5M decay heat calculations. Applying a stochastic sampling method, nuclear decay data uncertainties are first propagated for the cooling phase only. Thereafter, the uncertainty propagation is enlarged to gradually account for cross-section as well as fission yield uncertainties during the depletion phase. On that basis, assembly heat load uncertainties as well as total uncertainty for the entire pool are quantified for cooling times up to one year. The relative contributions from the various types of nuclear data uncertainties are in this context also estimated.

  9. Advanced scheme for high-yield laser driven nuclear reactions

    Czech Academy of Sciences Publication Activity Database

    Margarone, Daniele; Picciotto, A.; Velyhan, Andriy; Krása, Josef; Kucharik, M.; Mangione, A.; Szydlowsky, A.; Malinowska, A.; Bertuccio, G.; Shi, Y.; Crivellari, M.; Ullschmied, Jiří; Bellutti, P.; Korn, Georg

    2015-01-01

    Roč. 57, č. 1 (2015), s. 014030 ISSN 0741-3335 R&D Projects: GA MŠk ED1.1.00/02.0061; GA MŠk EE2.3.20.0279 EU Projects: European Commission(XE) 284464 - LASERLAB-EUROPE Grant - others:ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061; LaserZdroj (OP VK 3)(XE) CZ.1.07/2.3.00/20.0279 Institutional research plan: CEZ:AV0Z2043910 Institutional support: RVO:68378271 ; RVO:61389021 Keywords : laser plasma * nuclear reaction * laser fusion Subject RIV: BL - Plasma and Gas Discharge Physics; BH - Optics, Masers, Lasers (UFP-V) Impact factor: 2.404, year: 2015

  10. Nuclear-decay studies of neutron-rich rare-earth nuclides

    International Nuclear Information System (INIS)

    Chasteler, R.M.

    1990-01-01

    Neutron-rich rare-earth nuclei were produced in multinucleon transfer reactions of 170 Er and 176 Yb projectiles on nat W targets at the Lawrence Berkeley Laboratory SuperHILAC and their radioactive decays properties studied at the on-line mass separation facility OASIS. Two unknown isotopes, 169 Dy (t 1/2 = 39 ± 8 s) and 174 Er(t 1/2 = 3.3 ± 0.2 m) were discovered and their decay characteristics determined. The decay schemes for two previously identified isotopes, 168 Dy (t 1/2 = 8.8 ± 0.3 m) and 171 Ho (t 1/2 = 55 ± 3 s), were characterized. Evidence for a new isomer of 3.0 m 168 Ho g , 168 Ho m (t 1/2 = 132 ± 4 s) which decays by isomeric transition (IT) is presented. Beta particle endpoint energies were determined for the decay of 168 Ho g , 169 Dy, 171 Ho, and 174 Er, the resulting Qβ-values are: 2.93 ± 0.03, 3.2 ± 0.3, 3.2 ± 0.6, and 1.8 ± 0.2 MeV, respectively. These values were compared with values calculated using recent atomic mass formulae. Comparisons of various target/ion source geometries used in the OASIS mass separator facility for these multinucleon transfer reactions were performed. 73 refs., 40 figs., 11 tabs

  11. Improvement of gross theory of beta-decay for application to nuclear data

    Directory of Open Access Journals (Sweden)

    Koura Hiroyuki

    2017-01-01

    Full Text Available A theoretical study of β decay and delayed neutron has been carried out with a global β-decay model, the gross theory. The gross theory is based on a consideration of the sum rule of the β-strength function, and gives reasonable results of β-decay rates and delayed neutron in the entire nuclear mass region. In a fissioning nucleus, neutrons are produced by β decay of neutron-rich fission fragments from actinides known as delayed neutrons. The average number of delayed neutrons is estimated based on the sum of the β-delayed neutron-emission probabilities multiplied by the cumulative fission yield for each nucleus. Such a behavior is important to manipulate nuclear reactors, and when we adopt some new high-burn-up reactors, properties of minor actinides will play an important roll in the system, but these data have not been sufficient. We re-analyze and improve the gross theory. For example, we considered the parity of neutrons and protons at the Fermi surface, and treat a suppression for the allowed transitions in the framework of the gross theory. By using the improved gross theory, underestimated half-lives in the neutron-rich indium isotopes and neighboring region increase, and consequently follow experimental trend. The ability of reproduction (and also prediction of the β-decay rates, delayed-neutron emission probabilities is discussed. With this work, we have described the development of a programming code of the gross theory of β-decay including the improved parts. After preparation finished, this code can be released for the nuclear data community.

  12. Shamir secret sharing scheme with dynamic access structure (SSSDAS). Case study on nuclear power plant

    International Nuclear Information System (INIS)

    Thiyagarajan, P.; Thandra, Prasanth Kumar; Rajan, J.; Satyamurthy, S.A.V.; Aghila, G.

    2015-01-01

    In recent years, due to the sophistication offered by the Internet, strategic organizations like nuclear power plants are linked to the outside world communication through the Internet. The entry of outside world communication into strategic organization (nuclear power plant) increases the hacker's attempts to crack its security and to trace any information which is being sent among the top level officials. Information security system in nuclear power plant is very crucial as even small loophole in the security system will lead to a major disaster. Recent cyber attacks in nuclear power plant provoked information security professionals to look deeply into the information security aspects of strategic organizations (nuclear power plant). In these lines, Shamir secret sharing scheme with dynamic access structure (SSSDAS) is proposed in the paper which provides enhanced security by providing dynamic access structure for each node in different hierarchies. The SSSDAS algorithm can be applied to any strategic organizations with hierarchical structures. In this paper the possible scenarios where SSSDAS algorithm can be applied to nuclear power plant is explained as a case study. The proposed SSSDAS scheme identifies the wrong shares, if any, used for reconstruction of the secret. The SSSDAS scheme also address the three major security parameters namely confidentiality, authentication and integrity.

  13. Shamir secret sharing scheme with dynamic access structure (SSSDAS). Case study on nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Thiyagarajan, P.; Thandra, Prasanth Kumar; Rajan, J.; Satyamurthy, S.A.V. [Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam (India). Computer Div.; Aghila, G. [National Institute of Technology, Karaikal (India). Dept. of Computer Science and Engineering

    2015-05-15

    In recent years, due to the sophistication offered by the Internet, strategic organizations like nuclear power plants are linked to the outside world communication through the Internet. The entry of outside world communication into strategic organization (nuclear power plant) increases the hacker's attempts to crack its security and to trace any information which is being sent among the top level officials. Information security system in nuclear power plant is very crucial as even small loophole in the security system will lead to a major disaster. Recent cyber attacks in nuclear power plant provoked information security professionals to look deeply into the information security aspects of strategic organizations (nuclear power plant). In these lines, Shamir secret sharing scheme with dynamic access structure (SSSDAS) is proposed in the paper which provides enhanced security by providing dynamic access structure for each node in different hierarchies. The SSSDAS algorithm can be applied to any strategic organizations with hierarchical structures. In this paper the possible scenarios where SSSDAS algorithm can be applied to nuclear power plant is explained as a case study. The proposed SSSDAS scheme identifies the wrong shares, if any, used for reconstruction of the secret. The SSSDAS scheme also address the three major security parameters namely confidentiality, authentication and integrity.

  14. Interfaces of nuclear structure studies-decay vs. in-beam experiments

    International Nuclear Information System (INIS)

    Grawe, H.; Gorska, M.; Hu, Z.; Roeckl, E.; Lipoglavsek, M.; Fahlander, C.; Rykaczewski, K.

    1999-05-01

    The common interface of β-decay and particle-decay experiments and in-beam studies following fusion, relativistic fission and projectile fragmentation is defined by the search for the best way to extract nuclear structure information. For a few examples selected from the exotic regions of nuclei around 100 Sn and between 68 Ni and 78 Ni it is demonstrated, that complementary spectroscopic data extracted by various methods lead to an understanding of the shell structure at these keypoints of the nuclidic chart. (orig.)

  15. Controversy and consensus nuclear beta decay 1911-1934

    CERN Document Server

    Jensen, Carsten

    2000-01-01

    In 1920s, a long-lasting controversy on the interpretation of nuclear beta spectrum arose between Lise Meitner and Charles Drummond Ellis. This controversy, and the reactions from the contending parties when it was settled, reflect clearly the difference between the scientific communities in Berlin and Cambridge at that time. The Meitner-Ellis controversy ended in 1929, and it left an anomaly that attracted leading theoretical physicists. A new dispute, this time between Niels Bohr and Wolfgang Pauli, broke out. It concerned the explanation of the continuity of the primary beta particles and dominated the discussions for the next five years. Pauli argued for a new particle, and Bohr for a new theory; both suggestions were radical steps, but they reflected two different ways of doing physics.

  16. Heat transfer in the decay pool of irradiated nuclear fuel

    International Nuclear Information System (INIS)

    Lorenzini, E.; Spiga, M.; Zerbini, D.

    1987-01-01

    Present work aims to analyze mono-dimensional, time dependent trends of the water temperature, assuming that there are no auxiliary cooling systems; this can simulate one of the worst hypothetical accidents which may occur in a nuclear plant. In fact the cooling of the spent fuel is provided only by natural convection; in this situation it is an interesting matter to valuate the time evolution of the water temperature and its maximum value. The accuracy of this method requires a very large computer time and makes it rather heavy and expensive. In this paper, a method to perform the mono-dimensional transient thermal hydraulic analysis of the storage pool is proposed. The pool is subdivided in horizontal isothermal segments; for every segment an enthalpy balance equation is deduced, taking account of a vertical mixing flow rate between adjacent segments, due to the convective fluid streams up and down

  17. Analysis of floor technology scheme in open-top construction of nuclear power project

    International Nuclear Information System (INIS)

    Zhang Shuxia; Lu Qinwu; Han Xiaoping

    2014-01-01

    Open-top construction is general technology in Ⅲ generation in nuclear power project. Because traditional floor structure and its form board upholding doesn't meet open-top construction, four floor scheme are presented, whose characters, advantages and disadvantages, and its application are summarized. The research results will help to the application of open-top construction. (authors)

  18. Measuring nuclear reaction cross sections to extract information on neutrinoless double beta decay

    Science.gov (United States)

    Cavallaro, M.; Cappuzzello, F.; Agodi, C.; Acosta, L.; Auerbach, N.; Bellone, J.; Bijker, R.; Bonanno, D.; Bongiovanni, D.; Borello-Lewin, T.; Boztosun, I.; Branchina, V.; Bussa, M. P.; Calabrese, S.; Calabretta, L.; Calanna, A.; Calvo, D.; Carbone, D.; Chávez Lomelí, E. R.; Coban, A.; Colonna, M.; D’Agostino, G.; De Geronimo, G.; Delaunay, F.; Deshmukh, N.; de Faria, P. N.; Ferraresi, C.; Ferreira, J. L.; Finocchiaro, P.; Fisichella, M.; Foti, A.; Gallo, G.; Garcia, U.; Giraudo, G.; Greco, V.; Hacisalihoglu, A.; Kotila, J.; Iazzi, F.; Introzzi, R.; Lanzalone, G.; Lavagno, A.; La Via, F.; Lay, J. A.; Lenske, H.; Linares, R.; Litrico, G.; Longhitano, F.; Lo Presti, D.; Lubian, J.; Medina, N.; Mendes, D. R.; Muoio, A.; Oliveira, J. R. B.; Pakou, A.; Pandola, L.; Petrascu, H.; Pinna, F.; Reito, S.; Rifuggiato, D.; Rodrigues, M. R. D.; Russo, A. D.; Russo, G.; Santagati, G.; Santopinto, E.; Sgouros, O.; Solakci, S. O.; Souliotis, G.; Soukeras, V.; Spatafora, A.; Torresi, D.; Tudisco, S.; Vsevolodovna, R. I. M.; Wheadon, R. J.; Yildirin, A.; Zagatto, V. A. B.

    2018-02-01

    Neutrinoless double beta decay (0vββ) is considered the best potential resource to access the absolute neutrino mass scale. Moreover, if observed, it will signal that neutrinos are their own anti-particles (Majorana particles). Presently, this physics case is one of the most important research “beyond Standard Model” and might guide the way towards a Grand Unified Theory of fundamental interactions. Since the 0vββ decay process involves nuclei, its analysis necessarily implies nuclear structure issues. In the NURE project, supported by a Starting Grant of the European Research Council (ERC), nuclear reactions of double charge-exchange (DCE) are used as a tool to extract information on the 0vββ Nuclear Matrix Elements. In DCE reactions and ββ decay indeed the initial and final nuclear states are the same and the transition operators have similar structure. Thus the measurement of the DCE absolute cross-sections can give crucial information on ββ matrix elements. In a wider view, the NUMEN international collaboration plans a major upgrade of the INFN-LNS facilities in the next years in order to increase the experimental production of nuclei of at least two orders of magnitude, thus making feasible a systematic study of all the cases of interest as candidates for 0vββ.

  19. Measuring Uranium Decay Rates for Advancement of Nuclear Forensics and Geochronology

    Energy Technology Data Exchange (ETDEWEB)

    Parsons-Davis, Tashi [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-10-31

    Radioisotopic dating techniques are highly valuable tools for understanding the history of physical and chemical processes in materials related to planetary sciences and nuclear forensics, and rely on accurate knowledge of decay constants and their uncertainties. The decay constants of U-238 and U-235 are particularly important to Earth science, and often the measured values with lowest reported uncertainties are applied, although they have not been independently verified with similar precision. New direct measurements of the decay constants of U-238, Th-234, U-235, and U-234 were completed, using a range of analytical approaches. An overarching goal of the project was to ensure the quality of results, including metrological traceability to facilitate implementation across diverse disciplines. This report presents preliminary results of these experiments, as a few final measurements and calculations are still in progress.

  20. Simulations of Radioactive Decays: an Application of Low-Energy Electromagnetic Packages for the Nuclear Medicine

    Directory of Open Access Journals (Sweden)

    Munkhbaatar Batmunkh

    2015-12-01

    Full Text Available Problems of the radiobiology and the nuclear medicine require clarifying the specifi cs of radionuclides interactions with unhealthy cells. In this work we aimed to simulate emitting particles tracks of radionuclides and their radioactive decays at DNA level inside the cell nucleus. Accordingly, using the Monte Carlo-based track structure simulation technique, we estimated the radial distribution of deposited energy and kinetic energy spectra of electrons produced by primary particles resulting from radioactive decays of diff erent radionuclides within cell nucleus. To address the possibility of DNA damage, we performed the cluster analysis of track structures of emitted particles inside the volumes corresponding to the size of the native double-stranded DNA. For this purpose, G4-RadioactiveDecay and low- energy electromagnetic packages form Geant4 Monte-Carlo toolkit were combined together. Besides, a comparative analysis was performed for various low-energy electromagnetic packages as G4-DNA and G4-Livermore

  1. EDISTR: a computer program to obtain a nuclear decay data base for radiation dosimetry

    International Nuclear Information System (INIS)

    Dillman, L.T.

    1980-01-01

    This report provides documentation for the computer program EDISTR. EDISTR uses basic radioactive decay data from the Evaluated Nuclear Structure Data File developed and maintained by the Nuclear Data Project at the Oak Ridge National Laboratory as input, and calculates the mean energies and absolute intensities of all principal radiations associated with the radioactive decay of a nuclide. The program is intended to provide a physical data base for internal dosimetry calculations. The principal calculations performed by EDISTR are the determination of (1) the average energy of beta particles in a beta transition, (2) the beta spectrum as function of energy, (3) the energies and intensities of x-rays and Auger electrons generated by radioactive decay processes, (4) the bremsstrahlung spectra accompanying beta decay and monoenergetic Auger and internal conversion electrons, and (5) the radiations accompanying spontaneous fission. This report discusses the theoretical and empirical methods used in EDISTR and also practical aspects of the computer implementation of the theory. Detailed instructions for preparing input data for the computer program are included, along with examples and discussion of the output data generated by EDISTR

  2. EDISTR: a computer program to obtain a nuclear decay data base for radiation dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Dillman, L.T.

    1980-01-01

    This report provides documentation for the computer program EDISTR. EDISTR uses basic radioactive decay data from the Evaluated Nuclear Structure Data File developed and maintained by the Nuclear Data Project at the Oak Ridge National Laboratory as input, and calculates the mean energies and absolute intensities of all principal radiations associated with the radioactive decay of a nuclide. The program is intended to provide a physical data base for internal dosimetry calculations. The principal calculations performed by EDISTR are the determination of (1) the average energy of beta particles in a beta transition, (2) the beta spectrum as function of energy, (3) the energies and intensities of x-rays and Auger electrons generated by radioactive decay processes, (4) the bremsstrahlung spectra accompanying beta decay and monoenergetic Auger and internal conversion electrons, and (5) the radiations accompanying spontaneous fission. This report discusses the theoretical and empirical methods used in EDISTR and also practical aspects of the computer implementation of the theory. Detailed instructions for preparing input data for the computer program are included, along with examples and discussion of the output data generated by EDISTR.

  3. Laser assisted nuclear decay spectroscopy: A new method for studying neutron-deficient francium

    CERN Document Server

    Lynch, Kara Marie

    2015-01-01

    Radioactive decay studies of rare isotopes produced at radioactive ion beam facilities have often been hindered by the presence of isobaric and isomeric contamination. The Collinear Resonance Ionization Spectroscopy (CRIS) experiment at ISOLDE, CERN uses laser radiation to stepwise excite and ionize an atomic beam in a particular isomeric state. Deflection of this selectively ionized beam of exotic nuclei, from the remaining neutral contaminants, allows ultra-sensitive detection of rare isotopes and nuclear structure measurements in background-free conditions.\

  4. Workshop on nuclear structure and decay data: Theory and evaluation manual - Pt. 1

    International Nuclear Information System (INIS)

    Nichols, A.L.; McLaughlin, P.K.; p.mclaughlin@iaea.org

    2004-11-01

    A two-week Workshop on Nuclear Structure and Decay Data: Theory and Evaluation was organized and administrated by the IAEA Nuclear Data Section, and hosted at the Abdus Salam International Centre for Theoretical Physics (ICTP) in Trieste, Italy from 17 to 28 November 2003. The aims and contents of this workshop are summarized, along with the agenda, list of participants, comments and recommendations. Workshop materials are also included that are freely available on CD-ROM (all relevant PowerPoint presentations and manuals along with appropriate computer codes). (author)

  5. Workshop on nuclear structure and decay data: Theory and evaluation manual - Pt. 2

    International Nuclear Information System (INIS)

    Nichols, A.L.; McLaughlin, P.K.; p.mclaughlin@iaea.org

    2004-11-01

    A two-week Workshop on Nuclear Structure and Decay Data: Theory and Evaluation was organized and administrated by the IAEA Nuclear Data Section, and hosted at the Abdus Salam International Centre for Theoretical Physics (ICTP) in Trieste, Italy from 17 to 28 November 2003. The aims and contents of this workshop are summarized, along with the agenda, list of participants, comments and recommendations. Workshop materials are also included that are freely available on CD-ROM (all relevant PowerPoint presentations and manuals along with appropriate computer codes). (author)

  6. Nuclear responses for double-beta decays by hadron, photon, and neutrino probes and MOON experiment

    International Nuclear Information System (INIS)

    Ejiri, H.

    2006-01-01

    Neutrino-less double-beta decays (0νββ) with the mass sensitivities of the solar and atmospheric ν masses are of great interest for studying the Majorana nature of neutrinos and the absolute mass spectrum as suggested by recent ν oscillation experiments. Here nuclear responses (nuclear matrix elements) for 0νββ are crucial. They are well studied experimentally by using charge-exchange, photo-nuclear and neutrino reactions. MOON(Mo Observatory Of Neutrinos) is a high sensitivity 0νββ experiment with the mass sensitivity of an order of 30 meV. Experimental studies of the nuclear responses and the present status of MOON are briefly discussed. (author)

  7. Canonical Poly(A Polymerase Activity Promotes the Decay of a Wide Variety of Mammalian Nuclear RNAs.

    Directory of Open Access Journals (Sweden)

    Stefan M Bresson

    2015-10-01

    Full Text Available The human nuclear poly(A-binding protein PABPN1 has been implicated in the decay of nuclear noncoding RNAs (ncRNAs. In addition, PABPN1 promotes hyperadenylation by stimulating poly(A-polymerases (PAPα/γ, but this activity has not previously been linked to the decay of endogenous transcripts. Moreover, the mechanisms underlying target specificity have remained elusive. Here, we inactivated PAP-dependent hyperadenylation in cells by two independent mechanisms and used an RNA-seq approach to identify endogenous targets. We observed the upregulation of various ncRNAs, including snoRNA host genes, primary miRNA transcripts, and promoter upstream antisense RNAs, confirming that hyperadenylation is broadly required for the degradation of PABPN1-targets. In addition, we found that mRNAs with retained introns are susceptible to PABPN1 and PAPα/γ-mediated decay (PPD. Transcripts are targeted for degradation due to inefficient export, which is a consequence of reduced intron number or incomplete splicing. Additional investigation showed that a genetically-encoded poly(A tail is sufficient to drive decay, suggesting that degradation occurs independently of the canonical cleavage and polyadenylation reaction. Surprisingly, treatment with transcription inhibitors uncouples polyadenylation from decay, leading to runaway hyperadenylation of nuclear decay targets. We conclude that PPD is an important mammalian nuclear RNA decay pathway for the removal of poorly spliced and nuclear-retained transcripts.

  8. Application of the Broad Energy Germanium detector: A technique for elucidating β-decay schemes which involve daughter nuclei with very low energy excited states

    Energy Technology Data Exchange (ETDEWEB)

    Venhart, M., E-mail: martin.venhart@savba.sk [Institute of Physics, Slovak Academy of Sciences, SK-84511 Bratislava (Slovakia); Wood, J.L. [Department of Physics, Georgia Institute of Technology, Atlanta GA 30332 (United States); Boston, A.J. [Institute of Physics, Slovak Academy of Sciences, SK-84511 Bratislava (Slovakia); Cocolios, T.E. [School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL (United Kingdom); KU Leuven, Instituut voor Kern, en Stralingsfysica, B-3001 Leuven (Belgium); Harkness-Brennan, L.J.; Herzberg, R.-D.; Joss, D.T.; Judson, D.S. [Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Kliman, J.; Matoušek, V. [Institute of Physics, Slovak Academy of Sciences, SK-84511 Bratislava (Slovakia); Motyčák, Š. [Faculty of Electrical Engineering and Information Technology, Slovak University of Technology, SK-812 19 Bratislava (Slovakia); Page, R.D.; Patel, A. [Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Petrík, K.; Sedlák, M.; Veselský, M. [Institute of Physics, Slovak Academy of Sciences, SK-84511 Bratislava (Slovakia)

    2017-03-21

    A technique for elucidating β-decay schemes of isotopes with a large density of states at low excitation energy has been developed, in which a Broad Energy Germanium (BEGe) detector is used in conjunction with coaxial hyper-pure germanium detectors. The power of this technique is demonstrated using the example of {sup 183}Hg decay. Mass-separated samples of {sup 183}Hg were produced by a deposition of the low-energy radioactive-ion beam delivered by the ISOLDE facility at CERN. The excellent energy resolution of the BEGe detector allowed γ-ray energies to be determined with a precision of a few tens of eV, which was sufficient for the analysis of the Rydberg-Ritz combinations (in conjunction with γ-γ coincidences) in the level scheme. The timestamped structure of the data was used for unambiguous separation of γ rays arising from the decay of {sup 183}Hg from those due to the daughter decays.

  9. Nuclear processes induced by muon decay at the K-orbit of muonic atom

    International Nuclear Information System (INIS)

    Sabirov, B.; Abazov, V.; Dem'yanov, A.

    2012-01-01

    Results are presented of an experimental study of processes taking place in the case of muons stopping in nuclei. The aim of the experiment consists in investigating the possibility of a nucleus being excited when a muon on the K-orbit decays. The uniqueness of this process is that the nucleus, happening to be in the electromagnetic field of the muon occupying the lowest atomic orbit of angular momentum l=0, is jolted, when the muon decay μ - → e - ν μ ν e tilde occurs, and it mainly undergoes monopole excitation. The experiment aimed at searching for nuclear excitation related to a bound muon is based on the registration of coincidences between electrons from μ decays and γ quanta from nuclear transitions. An experimental installation MEGA has been created, which involves a set of scintillation counters for identifying muons stopping in the target enriched with powder-like samarium dioxide Sm 2 O 3 , a Ge(Li) γ detector with a sensitive volume ∼ 50 cm 3 and a Cherenkov counter made of TF-1 lead glass. The experiment was carried out with the muon beam in the low-background hall of the Phasotron of the JINR Laboratory of Nuclear Problems. The total number of muons that stopped in the target permitted to determine the upper limit for E0 excitation in the 152 Sm nucleus to be ω(E0) -3 , which is inferior to the level of the theoretical estimate (≅ 3 · 10 -4 ). The isomeric shift of the 121.78 keV level in the nucleus has been measured in the presence of a muon on the K-orbit of a muonic atom: ΔE is = 820 ±40 eV. The search for monopole excitation of a nucleus related to the decay of a bound muon is to be continued with the use of improved equipment and muon beams of higher intensity

  10. New Decay Data Sub-library for Calculation of Nuclear Reactors Antineutrino Spectra

    Science.gov (United States)

    Sonzogni, Alejandro; McCutchan, Elizabeth; Johnson, Timothy

    2015-10-01

    The ENDF/B-VII.1 decay data sub-library contains up-to-date decay properties for all known nuclides and can be used in a wide variety of applications such as decay heat, delayed nu-bar and astrophysics. We have recently completed an upgrade to the ENDF/B-VII.1 decay data sub-library in order to better calculate antineutrino spectra from fission of actinide nuclides. This sub-library has been used to identify the main contributors to the antineutrino spectra as well as to derive a systematic behavior of the energy integrated spectra similar to that of the beta-delayed neutron multiplicities. The main improvements have been the use of the TAGS data from Algora et al and Greenwood et al, as well as some of the single beta spectrum data from Rudstam et al to obtain beta minus level feedings. Additionally, we have calculated the antineutrino spectra for neutron energies higher than thermal, needed for highly-enriched uranium cores, such as the HFIR in ORNL that will be used in the PROSPECT experiment. These calculations are relevant since the high precision beta spectra which are used in many antineutrino calculations were measured at thermal energies. The impact of the fission yield data on these calculations will be discussed. This work was sponsored by the Office of Nuclear Physics, Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-98CH10886.

  11. A study of the recombination scheme dependence of jet production rates and of. alpha. sub s (Msub(Z sub 0 )) in hadronic Z sup 0 decays

    Energy Technology Data Exchange (ETDEWEB)

    Akrawy, M.Z.; Alexander, G.; Allison, J.; Allport, P.P.; Anderson, K.J.; Armitage, J.C.; Arnison, G.T.J.; Ashton, P.; Azuelos, G.; Baines, J.T.M.; Ball, A.H.; Banks, J.; Barker, G.J.; Barlow, R.J.; Batley, J.R.; Beck, A.; Becker, J.; Behnke, T.; Bell, K.W.; Bella, G.; Bethke, S.; Biebel, O.; Binder, U.; Bloodworth, I.J.; Bock, P.; Breuker, H.; Brown, R.M.; Brun, R.; Buijs, A.; Burckhart, H.J.; Capiluppi, P.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, D.G.; Chrin, J.T.M.; Clarke, P.E.L.; Cohen, I.; Collins, W.J.; Conboy, J.E.; Couch, M.; Coupland, M.; Cuffiani, M.; Dado, S.; Dallavalle, G.M.; Debu, P.; Deninno, M.M.; Dieckmann, A.; Dittmar, M.; Dixit, M.S.; Duchovni, E.; Duerdoth, I.P.; Dumans, D.J.P.; Elcombe, P.A.; Estabrooks, P.G.; Etzion, E.; Fabbri, F.; Farthouat, P.; Fischer, H.M.; Fong, D.G.; French, M.T.; Fukunaga, C.; Gaidot, A.; Ganel, O.; Gary, J.W.; Gascon, J.; Geddes, N.I.; Gee, C.N.P.; Geich-Gimbel, C.; Gensler, S.W.; Gentit, F.X.; Giacomelli, G.; G; OPAL Collaboration

    1991-02-01

    Jet production rates in hadronic Z{sup 0} decays are studied using four different recombination schemes to define resolvable jets. The strong coupling constant {alpha}{sub s}(Msub(Z{sup 0})) is determined in fits of the corresponding O({alpha}{sub s}{sup 2}) QCD calculations to the differential 2-jet distributions D{sub 2}(y). Hadronisation corrections and renormalisation scale uncertainties are found to be different for each recombination scheme. Within their overall systematic uncertainties, the four schemes yield consistent values of {alpha}{sub s}(Msub(Z{sup 0})), leading to a final result of {alpha}{sub s}(Msub(Z{sup 0}))=0.118{plus minus}0.008. The error includes the experimental uncertainties ({plus minus}0.003), uncertainties of hadronisation corrections and of the degree of parton virtualities to which the data are corrected, as well as the uncertainty of choosing the renormalisation scale. (orig.).

  12. Neutrino nuclear responses for double beta decays and astro neutrinos by charge exchange reactions

    Science.gov (United States)

    Ejiri, Hiroyasu

    2014-09-01

    Neutrino nuclear responses are crucial for neutrino studies in nuclei. Charge exchange reactions (CER) are shown to be used to study charged current neutrino nuclear responses associated with double beta decays(DBD)and astro neutrino interactions. CERs to be used are high energy-resolution (He3 ,t) reactions at RCNP, photonuclear reactions via IAR at NewSUBARU and muon capture reactions at MUSIC RCNP and MLF J-PARC. The Gamow Teller (GT) strengths studied by CERs reproduce the observed 2 neutrino DBD matrix elements. The GT and spin dipole (SD) matrix elements are found to be reduced much due to the nucleon spin isospin correlations and the non-nucleonic (delta isobar) nuclear medium effects. Impacts of the reductions on the DBD matrix elements and astro neutrino interactions are discussed.

  13. Signals of Bose Einstein condensation and Fermi quenching in the decay of hot nuclear systems

    Energy Technology Data Exchange (ETDEWEB)

    Marini, P., E-mail: marini@cenbg.in2p3.fr [Grand Accélérateur National d' Ions Lourds, Bd. Henri Becquerel, BP 55027, 14076 Caen (France); Zheng, H. [Cyclotron Institute, Texas A& M University, College Station, TX-77843 (United States); Laboratori Nazionali del Sud, INFN, via Santa Sofia, 62, 95123 Catania (Italy); Boisjoli, M. [Grand Accélérateur National d' Ions Lourds, Bd. Henri Becquerel, BP 55027, 14076 Caen (France); Laboratoire de Physique Nucléaire, Université Laval, Québec, G1V 0A6 (Canada); Verde, G. [Institut de Physique Nucléaire, CNRS-IN2P3, Univ. Paris-Sud, Université Paris-Saclay, 91406 Orsay Cedex (France); INFN – Sezione di Catania, via Santa Sofia, 64, 95123 Catania (Italy); Chbihi, A. [Grand Accélérateur National d' Ions Lourds, Bd. Henri Becquerel, BP 55027, 14076 Caen (France); Napolitani, P.; Ademard, G. [Institut de Physique Nucléaire, CNRS-IN2P3, Univ. Paris-Sud, Université Paris-Saclay, 91406 Orsay Cedex (France); Augey, L. [Laboratoire de Physique Corpusculaire, ENSICAEN, Université de Caen Basse Normandie, CNRS/IN2P3, F-14050 Caen Cedex (France); Bhattacharya, C. [Variable Energy Cyclotron Center, Kolkata (India); Borderie, B. [Institut de Physique Nucléaire, CNRS-IN2P3, Univ. Paris-Sud, Université Paris-Saclay, 91406 Orsay Cedex (France); Bougault, R. [Laboratoire de Physique Corpusculaire, ENSICAEN, Université de Caen Basse Normandie, CNRS/IN2P3, F-14050 Caen Cedex (France); and others

    2016-05-10

    We report on first experimental observations of nuclear fermionic and bosonic components displaying different behaviours in the decay of hot Ca projectile-like sources produced in mid-peripheral collisions at sub-Fermi energies. The experimental setup, constituted by the coupling of the INDRA 4π detector array to the forward angle VAMOS magnetic spectrometer, allowed to reconstruct the mass, charge and excitation energy of the decaying hot projectile-like sources. By means of quantum-fluctuation analysis techniques, temperatures and local partial densities of bosons and fermions could be correlated to the excitation energy of the reconstructed system. The results are consistent with the production of dilute mixed systems of bosons and fermions, where bosons experience higher phase-space and energy density as compared to the surrounding fermionic gas. Our findings recall phenomena observed in the study of Bose condensates and Fermi gases in atomic traps despite the different scales.

  14. Signals of Bose Einstein condensation and Fermi quenching in the decay of hot nuclear systems

    Directory of Open Access Journals (Sweden)

    P. Marini

    2016-05-01

    Full Text Available We report on first experimental observations of nuclear fermionic and bosonic components displaying different behaviours in the decay of hot Ca projectile-like sources produced in mid-peripheral collisions at sub-Fermi energies. The experimental setup, constituted by the coupling of the INDRA 4π detector array to the forward angle VAMOS magnetic spectrometer, allowed to reconstruct the mass, charge and excitation energy of the decaying hot projectile-like sources. By means of quantum-fluctuation analysis techniques, temperatures and local partial densities of bosons and fermions could be correlated to the excitation energy of the reconstructed system. The results are consistent with the production of dilute mixed systems of bosons and fermions, where bosons experience higher phase-space and energy density as compared to the surrounding fermionic gas. Our findings recall phenomena observed in the study of Bose condensates and Fermi gases in atomic traps despite the different scales.

  15. Many-body correlations of QRPA in nuclear matrix elements of double-beta decay

    International Nuclear Information System (INIS)

    Terasaki, J.

    2015-01-01

    We present two new ideas on the quasiparticle random-phase approximation (QRPA) approach for calculating nuclear matrix elements of double-beta decay. First, it is necessary to calculate overlaps of the QRPA states obtained on the basis of the ground states of different nuclei. We calculate this overlap using quasiboson vacua as the QRPA ground states. Second, we show that two-particle transfer paths are possible to use for the calculation under the closure approximation. A calculation is shown for 150 Nd→ 150 Sm using these two new ideas, and their implication is discussed

  16. Conception and design data of decay units in nuclear medical wards

    International Nuclear Information System (INIS)

    Strueter, H.D.; Hermsdorf, H.C.

    1981-01-01

    Authorities, users, and planners of sanitary equipment are given an insight into the various viewpoints of releasing radioactive effluents from the nuclear medical activities. Furthermore, a guideline for a reasonable establishing of nuclide-specific active effluents is shown which takes into consideration the legal and clinical concerns. In the second point, a modern, cost-saving technical solution is introduced which is based on an integrated compact decay storage concept (vacuum-toilet-system) which includes saving and controlling measures for water consumption. (DG) [de

  17. Charged Higgs production from polarized top-quark decay in the 2HDM considering the general-mass variable-flavor-number scheme

    Science.gov (United States)

    Abbaspour, S.; Mohammad Moosavi Nejad, S.

    2018-05-01

    Charged Higgs bosons are predicted by some non-minimal Higgs scenarios, such as models containing Higgs triplets and two-Higgs-doublet models, so that the experimental observation of these bosons would indicate physics beyond the Standard Model. In the present work, we introduce a channel to indirect search for the charged Higgses through the hadronic decay of polarized top quarks where a top quark decays into a charged Higgs H+ and a bottom-flavored meson B via the hadronization process of the produced bottom quark, t (↑) →H+ + b (→ B + jet). To obtain the energy spectrum of produced B-mesons we present, for the first time, an analytical expression for the O (αs) corrections to the differential decay width of the process t →H+ b in presence of a massive b-quark in the General-Mass Variable-Flavor-Number (GM-VFN) scheme. We find that the most reliable predictions for the B-hadron energy spectrum are made in the GM-VFN scheme, specifically, when the Type-II 2HDM scenario is concerned.

  18. Nuclear Shell Structure and Beta Decay I. Odd A Nuclei II. Even A Nuclei

    Science.gov (United States)

    Mayer, M.G.; Moszkowski, S.A.; Nordheim, L.W.

    1951-05-01

    In Part I a systematics is given of all transitions for odd A nuclei for which sufficiently reliable data are available. The allowed or forbidden characters of the transitions are correlated with the positions of the initial and final odd nucleon groups in the nuclear shell scheme. The nuclear shells show definite characteristics with respect to parity of the ground states. The latter is the same as the one obtained from known spins and magnetic moments in a one-particle interpretation. In Part II a systematics of the beta transitions of even-A nuclei is given. An interpretation of the character of the transitions in terms of nuclear shell structure is achieved on the hypothesis that the odd nucleon groups have the same structure as in odd-A nuclei, together with a simple coupling rule between the neutron and proton groups in odd-odd nuclei.

  19. Coordination of the international network of nuclear structure and decay data evaluators. Summary report of an IAEA advisory group meeting

    International Nuclear Information System (INIS)

    Muir, D.W.; Pronyaev, V.G.

    1998-03-01

    The international network of nuclear structure and decay data (NSDD) evaluators aims at a complete and periodic nuclear structure and decay data evaluation of all nuclides, the continuous publication of these evaluations and their dissemination to the scientific community. The evaluated data resulting from this concerted international effort are introduced in the Evaluated Structure and Decay Data File (ENSDF) and published in the journals Nuclear Physics A and Nuclear Data Sheets. Periodic meetings of this network are held in order to maintain the coordination of all centres and groups participating in the compilation, evaluation and dissemination of NSDD, to maintain and improve the standards and rules governing NSDS evaluation, and to review the development and common use of the computerized systems and databases maintained specifically for this activity. This document is a summary report of the twelfth Meeting on the Coordination of the NSDD Evaluators held between 14-18 October 1996 in Budapest, Hungary

  20. Summary Report of a Specialized Workshop on Nuclear Structure and Decay Data (NSDD) Evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, Alan L. [Univ. of Surrey, Guildford (United Kingdom); Dimitrious, P. [IAEA Nuclear Data Section, Vienna (Austria); Kondev, F. G. [Argonne National Lab. (ANL), Argonne, IL (United States); Ricard-McCutchan, E. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-04-27

    A three-day specialised workshop on Nuclear Structure and Decay Data Evaluations was organised and held at the headquarters of the International Atomic Energy Agency in Vienna, Austria, from 27 to 29 April 2015. This workshop covered a wide range of important topics and issues addressed when evaluating and maintaining the Evaluated Nuclear Structure Data File (ENSDF). The primary aim was to improve evaluators’ abilities to identify and understand the most appropriate evaluation processes to adopt in the formulation of individual ENSDF data sets. Participants assessed and reviewed existing policies, procedures and codes, and round-table discussions included the debate and resolution of specific difficulties experienced by ENSDF evaluators (i.e., all workshop participants). The contents of this report constitute a record of this workshop, based on the presentations and subsequent discussions.

  1. Nuclear structure data from in beam and decay studies around 254No

    International Nuclear Information System (INIS)

    Jones, P.

    2005-01-01

    The study of trans-fermium nuclei, the heaviest nuclei for which in-beam spectroscopy studies are possible has provided over recent years a rich tapestry of data. These have enhanced the mean field theories important for the prediction of nuclear properties at the limits of the nuclear chart. Developments in spectrometer and data-acquisition techniques at the Department of Physics, University of Jyvaskyla have further enhanced the studies. Utilising the RITU gas-filled spectrometer, the GREAT focal plane spectrometer, the identification recoils and their subsequent decay modes (alpha-, fission-, and gamma-ray decay) have been studied. The JUROGAM gamma-ray array of 43 Compton-suppressed HPGe detectors has been employed in the in-beam spectroscopy of the trans-fermium region. In-beam gamma-ray spectroscopy studies of trans-fermium nuclei 253 No, 254 No, 250 Fm, 251 Md, 253 No and 255 Lr have been performed, as well as detailed focal plane spectroscopy. Selected highlights of the work will be presented

  2. Nuclear Matrix Elements for the $\\beta\\beta$ Decay of the $^{76}$Ge

    CERN Document Server

    Brown, B A; Horoi, M

    2015-01-01

    The nuclear matrix elements for two-neutrino double-beta (2 n$\\beta\\beta$ ) and zero-neutrino double-beta (0 n$\\beta\\beta$) decay of 76 Ge are evaluated in terms of the configuration interaction (CI), quasiparticle random phase approximation (QRPA) and interacting boson model (IBM) methods. We show that the decomposition of the matrix elements in terms of interemediate states in 74 Ge is dominated by ground state of this nucleus. We consider corrections to the CI results that arise from configurations admixtures involving orbitals out-side of the CI configuration space by using results from QRPA, many-body-perturbation theory, and the connections to related observables. The CI two-neutrino matrix element is reduced due to the inclusion of spin-orbit partners, and to many-body correlations connected with Gamow-Teller beta decay. The CI zero-neutrino matrix element for the heavy neutrino is enhanced due to particle-particle correlations that are connected with the odd-even oscillations in the nuclear masse...

  3. Structure of nuclei with masses 76 and 82 and nuclear matrix elements of neutrinoless double beta decay

    Science.gov (United States)

    Yoshinaga, N.; Yanase, K.; Higashiyama, K.; Teruya, E.; Taguchi, D.

    2018-02-01

    Nuclear shell-model calculations are carried out for isobaric nuclei with masses 76 and 82. Energy spectra and electromagnetic transition rates are compared with the experimental data. Using the wavefunctions thus obtained, nuclear matrix elements for the neutrinoless double beta decay are estimated. In order to investigate the model dependence on the nuclear matrix elements, pair-truncated shell-model calculations are also performed. By comparing the results with those in other models, the nuclear matrix elements are found to be sensitive to the ground-state correlations. In particular, nuclear matrix elements have strong correlations with pairing gaps.

  4. Papers presented at the IAEA specialists' meeting on the development of an international nuclear decay data and cross-section database

    International Nuclear Information System (INIS)

    Lemmel, H.D.

    1994-12-01

    The present report contains 20 papers presented at the IAEA meeting on the Development of an International Nuclear Decay Data and Cross-Section Database, Vienna, 24-28 October 1994, covering the following topics: Wall-charts of nuclides, PC systems presenting nuclear data, nuclear decay-data and uncertainties, nuclear spectroscopy, thermal neutron cross-sections and resonance-integrals, reactor-neutron activation analysis, nuclear data standards. (author). Refs, figs and tabs

  5. $\\beta$-asymmetry measurements in nuclear $\\beta$-decay as a probe for non-standard model physics

    CERN Multimedia

    Roccia, S

    2002-01-01

    We propose to perform a series of measurements of the $\\beta$-asymmetry parameter in the decay of selected nuclei, in order to investigate the presence of possible time reversal invariant tensor contributions to the weak interaction. The measurements have the potential to improve by a factor of about four on the present limits for such non-standard model contributions in nuclear $\\beta$-decay.

  6. Fuel management scheme on 18 months refueling for Tianwan nuclear power station

    International Nuclear Information System (INIS)

    Li Youyi; Yang Xiaoqiang; Yao Jinguo; Wang Han; Dong Chao; Li Baoku

    2014-01-01

    To realize long period refueling for Tianwan Nuclear Power Station (TNPS) units 1 and 2, the fuel management scheme on transition to 18 months refueling was worked out. Referring to management experience in Russian nuclear power station, the long period refueling project shall adopt the new type fuel assembly TVS-2M. Before formal transition to long period fuel cycle, the mixed core compatibility was verified by the operation of pilot TVS-2M fuel assemblies. TVS-2M fuel assemblies replaced AFA fuel assemblies in two steps, namely, TVS-2M with blanket was loaded in the first two transition cycles, and TVS-2M without blanket was loaded in the subsequent cycles. The two TNPS units are scheduled to gradually increase operation length and finally reach 480 effective full-power day (EFPD) in four transition fuel cycles. Transition fuel cycles and equilibrium fuel cycles were all designed to adopt the part-low-leakage core fuel loading, which can reduce neutron irradiation to reactor pressure vessel. Fuel management schemes on 18 months refueling for TNPS enhance units capacity factor and economy, and have flexible cycle length. (authors)

  7. The possible test of the calculations of nuclear matrix elements of the (ββ)0ν-decay

    International Nuclear Information System (INIS)

    Bilenky, S.M.; Grifols, J.A.

    2002-01-01

    The existing calculations of the nuclear matrix elements of the neutrinoless double β-decay differ by about a factor three. This uncertainty prevents quantitative interpretation of the results of experiments searching for this process. We suggest here that the observation of the neutrinoless double β-decay of several nuclei could allow to test calculations of the nuclear matrix elements through the comparison of the ratios of the calculated lifetimes with experimental data. It is shown that the ratio of the lifetimes is very sensitive to different models

  8. Uncertainty of decay heat calculations originating from errors in the nuclear data and the yields of individual fission products

    International Nuclear Information System (INIS)

    Rudstam, G.

    1979-01-01

    The calculation of the abundance pattern of the fission products with due account taken of feeding from the fission of 235 U, 238 U, and 239 Pu, from the decay of parent nuclei, from neutron capture, and from delayed-neutron emission is described. By means of the abundances and the average beta and gamma energies the decay heat in nuclear fuel is evaluated along with its error derived from the uncertainties of fission yields and nuclear properties of the inddividual fission products. (author)

  9. No evidence for a decrease of nuclear decay rates with increasing heliocentric distance based on radiochronology of meteorites

    Science.gov (United States)

    Meier, Matthias M. M.; Wieler, Rainer

    2014-03-01

    It has been argued that the decay rates of several radioactive nuclides are slightly lower at Earth's aphelion than at perihelion, and that this effect might depend on heliocentric distance. It might then be expected that nuclear decay rates be considerably lower at larger distances from the sun, e.g., in the asteroid belt at 2-3 AU from where most meteorites originate. If so, ages of meteorites obtained by analyses of radioactive nuclides and their stable daughter isotopes might be in error, since these ages are based on decay rates determined on Earth. Here we evaluate whether the large data base on nuclear cosmochronology offers any hint for discrepancies which might be due to radially variable decay rates. Chlorine-36 (t1/2 = 301,000 a) is produced in meteorites by interactions with cosmic rays and is the nuclide for which a decay rate dependence from heliocentric distance has been proposed, which, in principle, can be tested with our approach and the current data base. We show that compilations of 36Cl concentrations measured in meteorites offer no support for a spatially variable 36Cl decay rate. For very short-lived cosmic-ray produced radionuclides (half-lives uranium decay rates in different meteorite parent bodies in the asteroid belt. Moreover, the oldest U-Pb ages of meteorites agree with the main-sequence age of the sun derived from helioseismology within the formal ˜1% uncertainty of the latter. Meteorite ages also provide no evidence for a decrease of decay rates with heliocentric distance for nuclides such as 87Rb (decay mode β-) 40K (β- and electron capture), and 147Sm (α).

  10. Potential for α -induced nuclear scattering, reaction and decay, and a resonance-pole-decay model with exact explicit analytical solutions

    Science.gov (United States)

    Sahu, Basudeb; Bhoi, Swagatika

    2017-10-01

    The decay of α particle from a nucleus is viewed as a quantum resonance state of a two-body scattering process of the α +daughter nucleus pair governed by a novel nucleus-nucleus potential in squared Woods-Saxon form. By the application of the rigorous optical model (OM) potential scattering (S -matrix) theory the genuineness of the potential for the system is established by giving a good explanation of the elastic scattering and reaction cross sections data of the α +nucleus pair. From the pole position in the complex momentum (k ) plane of the S matrix of the real part of the OM potential defined above, the energy and width of the resonance state akin to the decaying state of emission of α particle are extracted and from this width, the result of the α -decay half-life is derived to account for the experimental result of the half-life in the cases of a large number of α emitters including heavy and superheavy nuclei. The S matrix of the real OM potential is replaced by an analytical function expressed in terms of exact Schrödinger solutions of a global potential that closely represents the real Coulomb-nuclear interaction in the interior and the pure Coulomb wave functions outside, and the resonant poles of this S matrix in the complex momentum plane are used to give satisfactory results of decay half-lives of α coming out from varieties of nuclei.

  11. The Re-evaluation of 84Rb decay data

    International Nuclear Information System (INIS)

    Huang Xiaolong; Zhou Chunmei

    1996-01-01

    The 84 Rb is an important radionuclide and its decay data are fundamental data in nuclear applications. The decay data for 84 Rb were re-evaluated. The energies and intensities of γ rays and their internal conversion coefficients, energies and intensities of Auger electrons, conversion electrons and x-rays, were recommended. The decay scheme was also given. The balance of radiation rays intensities and energies was checked. (9 tabs., 2 figs.)

  12. A proposal of new nuclear communication scheme based on qualitative research

    International Nuclear Information System (INIS)

    Yagi, Ekou; Takahashi, Makoto; Kitamura, Masaharu

    2007-01-01

    An action research project called dialogue forum has been conducted in this study. The essential constituent of the project is a series of repetitive dialogue sessions carried out by lay citizens, nuclear experts, and a facilitator. One important feature of the project is that the study has been conducted based on the qualitative research methodology. The changes in opinions and attitude of the dialogue participants have been analyzed by an ethno-methodological approach. The observations are summarized as follows. The opinions of the citizen participants showed a significant shift from emotional to practical representations along with the progression of the dialogue sessions. Meanwhile, their attitude showed a marked tendency from problem-statement-oriented to problem-solving-oriented representation. On the other hand, the statements of the expert participants showed a significant shift from expert-based to citizen-based risk recognition and description, and their attitude showed a clear tendency from teaching-oriented to colearning-oriented thinking. These changes of opinions and attitude have been interpreted as a coevolving rather than a single process. It can be stressed that this type of change is most important for the reestablishment of mutual trust between the citizens and the nuclear experts. In this regard The Process Model of Coevolution of Risk Recognition' has been proposed as a guideline for developing a new scheme of public communication concerning nuclear technology. The proposed process model of coevolution of risk recognition is regarded to be essential for appropriate relationship management between nuclear technology and society in the near future. (author)

  13. The limits of the nuclear chart set by fission and alpha decay

    Directory of Open Access Journals (Sweden)

    Möller Peter

    2016-01-01

    Full Text Available I will review how our picture of heavy-element nuclear structure has evolved through remarkably simple ideas and related models. It is well known that the Bethe-Weizsäcker semi-empirical mass model had an important role in unraveling radioactive decay and element transmutation in the heavy-element region in the 1930s. A remarkable aspect is that this model could immediately after the discovery of fission be generalized to explain this phenomenon through the consideration of deformation of a charged liquid drop. Bethe and Bacher already raised the possibility that shell structure (by them calculated in terms of a single-particle oscillator potential could give rise to noticeable deviations between results of the macroscopic mass model and experiment but limited data prevented firm conclusions. In the 1950s the single-particle models took a realistic form and also included deformation. The possibility of the existence of a relatively stable “island” of superheavy elements was raised already then. But it was not until the work by Strutinsky in the mid 1960s that a quantitative model for the nuclear potential-energy emerged in the form of the macroscopic-microscopic model. Although new elements have been discovered at an almost steady pace since 1940, theory indicates that we are close to the end of this era: repulsive Coulomb effects will set the limit of observable elements to near Z = 120.

  14. Evaluation procedures for experimental decay data

    International Nuclear Information System (INIS)

    Bunting, R.L.; Reich, C.W.

    1981-01-01

    The file of radioactive-nuclide decay data included in ENDF/B is intended to provide a commonly available base of evaluated decay data relevant to reactor research and technology and to nuclear-power applications. Consequently, the types of data it contains have been carefully chosen to permit their application to a wide variety of reactor-related problems while still retaining a relatively compact size. The history and purpose of the decay-data evaluations for ENDF/B are reviewed together with the sources and types of experimental data considered. The importance of the generic relationships of the radiations emitted following nuclear decay is discussed and their treatment in ENDF/B is illustrated. For purposes of illustration, an example of an experimental decay-data evaluation is presented. The procedures for accounting for the various atomic processes associated with nuclear decay are presented. The increasing availability of data from the study of the complex decay schemes of nuclides with large decay energies (e.g., short-lived fission products) presents a special challenge for reactor-related decay-data evaluations. The unique problems posed by inherent limitations in these data are pointed out. The need for new data types and expermental techniques specially tailored to prodice the information required for reactor-technology applications is indicated. The potential relevance of existing beta-strength-function measurements as one means of addressing these problems is discussed

  15. A scheme for the audit of scientific and technological standards in clinical nuclear medicine

    International Nuclear Information System (INIS)

    Perkins, A.C.; Jarritt, P.H.

    2002-01-01

    Aim: Audit is the process whereby the quality of a service is monitored and optimised. It forms an essential component of the quality assurance process, whether by self-assessment or by external peer review. In the UK the British Nuclear Medicine Society (BNMS) has undertaken external organisational audit of departments providing clinical nuclear medicine services. This work aimed to develop a more thorough and service specific process for the audit of scientific and technological standards in nuclear medicine. Materials and Methods: The audit process has been implemented using written audit documents to facilitate the audit procedure. A questionnaire forms part of the formal documentation for audit of the scientific and technical standards of a clinical service. Scientific and technical standards were derived from a number of sources including legal requirements, regulatory obligations, notes for guidance, peer reviewed publications and accepted good clinical practice (GCP). Results: The audit process graded the standards of an individual department according to legal or safety requirements (Grade A), good practice (Grade B) and desirable aspects of service delivery (Grade C). The standards have been allocated into eight main categories. These are: Instrumentation; Software and data protection; Electrical Safety; Mechanical Safety; Workstation Safety; The Control of Substances Hazardous to Health (COSHH); Radiation Protection; Scientific and Technical staffing levels. During the audit visit a detailed inspection of clinical and laboratory areas and department written documentation is also necessary to validate the data obtained. Conclusion: The printed scheme now provides a means for external audit or self-assessment. There should be evidence of a well-organised and safe environment for both patients and staff. Health and Safety legislation requires written local rules and these records should be available to demonstrate the standard of service provision. Other

  16. A control volume scheme for three-dimensional transport: buffer and matrix effect on a decay chain transport in the repository

    International Nuclear Information System (INIS)

    Lee, Y. M.; Hwang, Y. S.; Kim, S. G.; Kang, C. H.

    2002-01-01

    Using a three-dimensional numerical code, B3R developed for nuclide transport of an arbitrary length of decay chain in the buffer between the canister and adjacent rock in a high-level radioactive waste repository by adopting a finite difference method utilizing the control-volume scheme, some illustrative calculations have been done. A linear sorption isotherm, nuclide transport due to diffusion in the buffer and the rock matrix, and advection and dispersion along thin rigid parallel fractures existing in a saturated porous rock matrix as well as diffusion through the fracture wall into the matrix is assumed. In such kind of repository, buffer and rock matrix are known to be important physico-chemical barriers in nuclide retardation. To show effects of buffer and rock matrix on nuclide transport in HLW repository and also to demonstrate usefulness of B3R, several cases of breakthrough curves as well as three-dimensional plots of concentration isopleths associated with these two barriers are introduced for a typical case of decay chain of 234 U→ 230 Th→ 226 Ra, which is the most important chain as far as the human environment is concerned

  17. Influence of the nuclear electric field on processes of annihilation of positrons emitted at β+-decay

    Directory of Open Access Journals (Sweden)

    S. N. Fedotkin

    2014-12-01

    Full Text Available The process of atomic shell ionization during annihilation of positron, emitted at β+-decay, with K-electron of daughter's atom is considered. The role of nuclear Coulomb field at calculation of the probability of this process is investigated. It is shown that the correct account of the influence of this factor on the states of electron and posi-tron changes the probability of atomic ionization appreciably. The ratio of the probabilities of processes of atom-ic ionization and usual β+- decay is notably changed.

  18. Co-ordination of the international network of nuclear structure and decay data evaluators. Summary report of an IAEA advisory group meeting

    International Nuclear Information System (INIS)

    Pronyaev, V.G.

    2001-02-01

    The IAEA Nuclear Data Section convened the fourteenth meeting of the International Nuclear Structure and Decay Data Evaluators Network at IAEA Headquarters, Vienna, 4-7 December 2000. The meeting was attended by 22 scientists from 7 Member States and 1 international organization concerned with compilation, evaluation, and dissemination of nuclear structure and decay data. The present document contains a meeting summary, the recommendations, the data center reports and proposals considered by the participants. (author)

  19. Co-ordination of the International Network of Nuclear Structure and Decay Data Evaluators. Summary report of an IAEA Technical Meeting

    International Nuclear Information System (INIS)

    Nichols, A.L.; Tuli, J.K.

    2007-09-01

    The IAEA Nuclear Data Section convened the 17th meeting of the International Network of Nuclear Structure and Decay Data Evaluators in St. Petersburg, Russian Federation, 11-15 June 2007. This meeting was attended by 27 scientists from 13 Member States concerned with the compilation, evaluation and dissemination of nuclear structure and decay data. A summary of the meeting, recommendations/conclusions, data centre reports, and various proposals considered, modified and agreed by the participants are contained within this document. (author)

  20. Co-ordination of the international network of nuclear structure and decay data evaluators. Summary report of an IAEA advisory group meeting

    International Nuclear Information System (INIS)

    Pronyaev, V.G.

    1999-03-01

    The IAEA Nuclear Data Section convened the thirteenth meeting of the International Nuclear Structure and Decay Data Evaluators Network at the IAEA Headquarters, Vienna, 14-17 December 1998. The meeting was attended by 30 scientists from 10 Member States and 2 international organizations concerned with compilation, evaluation, and dissemination of nuclear structure and decay data. The present document contains a meeting summary, the conclusions and recommendations, the data center reports and proposals considered by the participants. (author)

  1. Development of a new electron-RI colliding scheme for study of unstable nuclear structure

    International Nuclear Information System (INIS)

    Wakasugi, M.; Emoto, T.; Ishihara, M.; Koseki, T.; Ohnishi, T.; Suda, T.; Takeda, H.; Yano, Y.; Kurita, K.

    2004-01-01

    A new method of electron scattering experiment for unstable nuclei is proposed. In this method, the low energy ion beam is injected into the electron storage ring where the transverse potential well made by electron beam exists. The ion beam is three-dimensionally confined by applying longitudinal static mirror potential externally. The ion beam confined on the electron beam axis is regarded as the Self-Confining Radioactive Ion Target (SCRIPT). This idea originally comes from the ion trap phenomenon of the electron storage ring. For the electron scattering experiment, luminosity higher than 10 26 s -1 cm -2 is required for heavy nuclei. In order to test this idea, computer simulation is performed. Limit of the storage of positive charges, change of the ion valences caused by the collisions with the electrons, nuclear decays and capture of residual gas, other interactions and the luminosity are investigated. Demonstration of this idea is under way at the KSR storage ring of Kyoto University with the SCRIPT instrument equipped with forty built-in electrodes. It is expected that the number of ions accumulated and the luminosity of the collisions are about 10 6 and 2x10 25 s -1 cm -2 , respectively, at the electron beam energy of 100 MeV and current of 100 mA(max). (S. Funahashi)

  2. Spectroscopy of element 115 decay chains.

    Science.gov (United States)

    Rudolph, D; Forsberg, U; Golubev, P; Sarmiento, L G; Yakushev, A; Andersson, L-L; Di Nitto, A; Düllmann, Ch E; Gates, J M; Gregorich, K E; Gross, C J; Heßberger, F P; Herzberg, R-D; Khuyagbaatar, J; Kratz, J V; Rykaczewski, K; Schädel, M; Åberg, S; Ackermann, D; Block, M; Brand, H; Carlsson, B G; Cox, D; Derkx, X; Eberhardt, K; Even, J; Fahlander, C; Gerl, J; Jäger, E; Kindler, B; Krier, J; Kojouharov, I; Kurz, N; Lommel, B; Mistry, A; Mokry, C; Nitsche, H; Omtvedt, J P; Papadakis, P; Ragnarsson, I; Runke, J; Schaffner, H; Schausten, B; Thörle-Pospiech, P; Torres, T; Traut, T; Trautmann, N; Türler, A; Ward, A; Ward, D E; Wiehl, N

    2013-09-13

    A high-resolution α, x-ray, and γ-ray coincidence spectroscopy experiment was conducted at the GSI Helmholtzzentrum für Schwerionenforschung. Thirty correlated α-decay chains were detected following the fusion-evaporation reaction 48Ca + 243Am. The observations are consistent with previous assignments of similar decay chains to originate from element Z=115. For the first time, precise spectroscopy allows the derivation of excitation schemes of isotopes along the decay chains starting with elements Z>112. Comprehensive Monte Carlo simulations accompany the data analysis. Nuclear structure models provide a first level interpretation.

  3. Neutrinoless ββ decay mediated by the exchange of light and heavy neutrinos: the role of nuclear structure correlations

    Science.gov (United States)

    Menéndez, J.

    2018-01-01

    Neutrinoless β β decay nuclear matrix elements calculated with the shell model and energy-density functional theory typically disagree by more than a factor of two in the standard scenario of light-neutrino exchange. In contrast, for a decay mediated by sterile heavy neutrinos the deviations are reduced to about 50%, an uncertainty similar to the one due to short-range effects. We compare matrix elements in the light- and heavy-neutrino-exchange channels, exploring the radial, momentum transfer and angular momentum-parity matrix element distributions, and considering transitions that involve correlated and uncorrelated nuclear states. We argue that the shorter-range heavy-neutrino exchange is less sensitive to collective nuclear correlations, and that discrepancies in matrix elements are mostly due to the treatment of long-range correlations in many-body calculations. Our analysis supports previous studies suggesting that isoscalar pairing correlations, which affect mostly the longer-range part of the neutrinoless β β decay operator, are partially responsible for the differences between nuclear matrix elements in the standard light-neutrino-exchange mechanism.

  4. Dynamic aspects of the nuclear decay: from the fission to the multifragmentation

    International Nuclear Information System (INIS)

    Gruyer, Diego

    2014-01-01

    In this work we study the evolution and nature of reaction and decay mechanisms of hot nuclei produced in heavy ion collisions from E = 8 to 25 MeV/A measured with INDRA. In central Xe+Sn collisions from E = 8 to 25 MeV/A, three-fragment events present a significant cross section without the underlying production mechanism being clearly established. We have shown that fragments arise from two successive binary splittings. The time interval between these two splittings decreases with increasing incident energy, becoming compatible with a simultaneous three-body break-up above E = 20 MeV/A, which was interpreted as the signature of the onset of multifragmentation. Then we have investigated the nature of the multifragmentation process. A statistical analysis of the largest fragment charge (Zmax) distribution produced in central Xe+Sn collisions at E = 25-50 MeV/A allowed us to establish that multifragmentation is a dynamical aggregation process. It also demonstrates the effects of collective radial expansion on multifragmentation partitions through the link between the timescale of the process and the shape of the Zmax distribution. The comparison of fragmentation patterns of comparable size systems produced in symmetric (Xe+Sn) and asymmetric (Ta+Zn) central collisions, which are supposed to follow different trajectories in the nuclear phase diagram, confirm the link between collective radial expansion and fragment partitions in multifragmentation. (author) [fr

  5. A new scanning system for alpha decay events as calibration sources for range-energy relation in nuclear emulsion

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, J., E-mail: jyoshida@gifu-u.ac.jp; Kinbara, S.; Mishina, A.; Nakazawa, K.; Soe, M.K.; Theint, A.M.M.; Tint, K.T.

    2017-03-01

    A new scanning system named “Vertex picker” has been developed to rapid collect alpha decay events, which are calibration sources for the range-energy relation in nuclear emulsion. A computer-controlled optical microscope scans emulsion layers exhaustively, and a high-speed and high-resolution camera takes their micrographs. A dedicated image processing picks out vertex-like shapes. Practical operations of alpha decay search were demonstrated by emulsion sheets of the KEK-PS E373 experiment. Alpha decays of nearly 28 events were detected in eye-check work on a PC monitor per hour. This yield is nearly 20 times more effective than that by the conventional eye-scan method. The speed and quality is acceptable for the coming new experiment, J-PARC E07.

  6. A new scanning system for alpha decay events as calibration sources for range-energy relation in nuclear emulsion

    International Nuclear Information System (INIS)

    Yoshida, J.; Kinbara, S.; Mishina, A.; Nakazawa, K.; Soe, M.K.; Theint, A.M.M.; Tint, K.T.

    2017-01-01

    A new scanning system named “Vertex picker” has been developed to rapid collect alpha decay events, which are calibration sources for the range-energy relation in nuclear emulsion. A computer-controlled optical microscope scans emulsion layers exhaustively, and a high-speed and high-resolution camera takes their micrographs. A dedicated image processing picks out vertex-like shapes. Practical operations of alpha decay search were demonstrated by emulsion sheets of the KEK-PS E373 experiment. Alpha decays of nearly 28 events were detected in eye-check work on a PC monitor per hour. This yield is nearly 20 times more effective than that by the conventional eye-scan method. The speed and quality is acceptable for the coming new experiment, J-PARC E07.

  7. Conformational and nuclear dynamics effects in molecular Auger spectra: fluorine core-hole decay in CF4

    Science.gov (United States)

    Arion, T.; Takahashi, O.; Püttner, R.; Ulrich, V.; Barth, S.; Lischke, T.; Bradshaw, A. M.; Förstel, M.; Hergenhahn, U.

    2014-06-01

    In a molecular Auger spectrum information on the decaying state is implicitly ensemble-averaged. For a repulsive core-ionized state, for example, contributions from all parts of its potential curve are superimposed in the Auger spectrum. Using carbon tetrafluoride (CF4, tetrafluoromethane), we demonstrate for the first time that these contributions can be disentangled by recording photoelectron-Auger electron coincidence spectra with high energy resolution. For the F K-VV spectrum of CF4, there are significant differences in the Auger decay at different intermediate state (single core hole) geometries. With the help of calculations, we show that these differences result primarily from zero-point fluctuations in the neutral molecular ground state, but are amplified by the nuclear dynamics during Auger decay.

  8. Conformational and nuclear dynamics effects in molecular Auger spectra: fluorine core-hole decay in CF4

    International Nuclear Information System (INIS)

    Arion, T; Ulrich, V; Barth, S; Lischke, T; Bradshaw, A M; Takahashi, O; Püttner, R; Förstel, M; Hergenhahn, U

    2014-01-01

    In a molecular Auger spectrum information on the decaying state is implicitly ensemble-averaged. For a repulsive core-ionized state, for example, contributions from all parts of its potential curve are superimposed in the Auger spectrum. Using carbon tetrafluoride (CF 4 , tetrafluoromethane), we demonstrate for the first time that these contributions can be disentangled by recording photoelectron–Auger electron coincidence spectra with high energy resolution. For the F K-VV spectrum of CF 4 , there are significant differences in the Auger decay at different intermediate state (single core hole) geometries. With the help of calculations, we show that these differences result primarily from zero-point fluctuations in the neutral molecular ground state, but are amplified by the nuclear dynamics during Auger decay. (paper)

  9. Data processing in gamma spectrometry. Application to the decay schemes study; Traitement des informations en spectrometrie gamma application a l'etude de schemas de desintegration

    Energy Technology Data Exchange (ETDEWEB)

    Boulanger, J.P. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires, departement d' electronique generale, service d' instrumentation nucleaire

    1968-06-01

    The purpose of this thesis is the processing of the data issued from a gamma spectrometer, and its applications to the decay schemes study. The mathematical analysis of the full energy peaks, in connection with the very good resolution of semi-conductor detectors, leads to a very accurate determination of the energies. The resolution of complex spectra by the least squares method, completed by a spectra generating process, allows the calculation of branching ratios. Then, the handling of the two dimensional experiments permits the coincidence exam. For each of these methods, the calculation principle, then the systematics tests realized in order to prove their validity and to determine their application ranges as well as some experimental results appropriate to illustrate their possibilities, are presented. The energies of some nuclides, frequently used as standards have been thus measured and the decay schemes of {sup 134}Cs and {sup 110m}Ag determined precisely. (author) [French] Cette these est consacree aux methodes de traitement des informations issues d'un spectrometre {gamma}, et a leur application a l'etude des schemas de desintegration: l'analyse mathematique des pics d'absorption totale, conjuguee avec l'excellent pouvoir de resolution des detecteurs semi-conducteurs, conduit a une determination tres precise des energies. La decomposition des spectres complexes par la methode des moindres carres, completee par un procede de generation de spectres, autorise le calcul des rapports de branchement. Enfin le depouillement des experiences biparametriques permet l'examen des coincidences. Pour chacune de ces methodes, on expose le principe des calculs et les essais systematiques effectues afin d'eprouver leur validite et de definir leurs domaines d'application, ainsi que quelques resultats experimentaux propres a illustrer leurs possibilites. Les energies de quelques isotopes utilises couramment comme etalons ont ainsi ete

  10. Reaction theory for analysis of nuclear giant resonances production and decay processes

    International Nuclear Information System (INIS)

    Foglia, G.A.

    1991-01-01

    The existence of mixing parameters connected to the different decay forms of the giant resonances was theoretically justified, and their energy dependence determined as well using a reaction theory which treats in a consistent manner the giant multipolar resonances formation and their different decay modes. (L.C.J.A.)

  11. Comparison of the lattice Boltzmann equation and discrete unified gas-kinetic scheme methods for direct numerical simulation of decaying turbulent flows.

    Science.gov (United States)

    Wang, Peng; Wang, Lian-Ping; Guo, Zhaoli

    2016-10-01

    The main objective of this work is to perform a detailed comparison of the lattice Boltzmann equation (LBE) and the recently developed discrete unified gas-kinetic scheme (DUGKS) methods for direct numerical simulation (DNS) of the decaying homogeneous isotropic turbulence and the Kida vortex flow in a periodic box. The flow fields and key statistical quantities computed by both methods are compared with those from the pseudospectral method at both low and moderate Reynolds numbers. The results show that the LBE is more accurate and efficient than the DUGKS, but the latter has a superior numerical stability, particularly for high Reynolds number flows. In addition, we conclude that the DUGKS can adequately resolve the flow when the minimum spatial resolution parameter k_{max}η>3, where k_{max} is the maximum resolved wave number and η is the flow Kolmogorov length. This resolution requirement can be contrasted with the requirements of k_{max}η>1 for the pseudospectral method and k_{max}η>2 for the LBE. It should be emphasized that although more validations should be conducted before the DUGKS can be called a viable tool for DNS of turbulent flows, the present work contributes to the overall assessment of the DUGKS, and it provides a basis for further applications of DUGKS in studying the physics of turbulent flows.

  12. Role of proper response schemes, legislation and regional cooperation in combating illicit trafficking of nuclear materials in developing countries

    International Nuclear Information System (INIS)

    Sterzov, A.

    2002-01-01

    proper model scheme for the developing countries is important for starting the initial process of preventing and combating the illicit traffic of nuclear materials. There is a need of reinforcing strategy to control the existing stockpiles of fissile material and to lower the future production and use of such materials. The illicit traffic of nuclear materials is a new threat, which requires rapid implementation of comprehensive, mutually measures and efforts, new approaches, coordination of services and institutions and even new legislation. IV. Action Scheme for illicit radioactive or nuclear material It was felt that the application of a new model scheme would allow better and quicker response of Bulgarian capabilities for combating illicit nuclear trafficking. First Step 1. Health physics analysis (gamma and neutron dose) 2. Preservation of evidence (proper protocols adopted by the law enforcement forces) Second Step 1. NDA analysis to categorize the radioactive material on site: radioactive, non-fissile material; nuclear fuel ( 235 U content less 20 %); Pu and/or enriched U ( 235 U content higher 20 %) 2. Ge(Li) high Resolution Gamma Spectroscopy 3. Passive Neutron interrogation for Pu Third Step 1. In-Depth Analysis by Specialized laboratory: Analysis of the matrix, of packaging material; element composition of nuclear material; impurities, traces etc. V. Setting up a Legal and Administrative Frame. The creation and proposition of a model scheme procedure for the developing countries is important for starting the initial process of preventing and combating the illicit traffic of nuclear materials. The proposition of a model procedure will allow better and quicker upgrade of developing countries capabilities for combating illicit nuclear trafficking. It is also important to initiate the contacts between neighbouring countries by regional collaboration of law enforcement authorities, customs, analytical laboratories etc. which will make combating illicit trafficking

  13. Isotensor Axial Polarizability and Lattice QCD Input for Nuclear Double- β Decay Phenomenology

    Energy Technology Data Exchange (ETDEWEB)

    Shanahan, Phiala E.; Tiburzi, Brian C.; Wagman, Michael L.; Winter, Frank; Chang, Emmanuel; Davoudi, Zohreh; Detmold, William; Orginos, Kostas; Savage, Martin J.

    2017-08-01

    The potential importance of short-distance nuclear effects in double-$\\beta$ decay is assessed using a lattice QCD calculation of the $nn\\rightarrow pp$ transition and effective field theory methods. At the unphysical quark masses used in the numerical computation, these effects, encoded in the isotensor axial polarisability, are found to be of similar magnitude to the nuclear modification of the single axial current, which phenomenologically is the quenching of the axial charge used in nuclear many-body calculations. This finding suggests that nuclear models for neutrinoful and neutrinoless double-$\\beta$ decays should incorporate this previously neglected contribution if they are to provide reliable guidance for next-generation neutrinoless double-$\\beta$ decay searches. The prospects of constraining the isotensor axial polarisabilities of nuclei using lattice QCD input into nuclear many-body calculations are discussed.

  14. Nuclear fragmentation with secondary decay in the context of conventional percolation model

    International Nuclear Information System (INIS)

    Santiago, A.J.

    1989-09-01

    Mass and energy spectra arising from proton-nucleus collisions at energies between 80 and 350 GeV were studied, using the conventional percolation model coupled with secondary decay of the clusters. (L.C.J.A.)

  15. Double beta decay, neutrino physics, nuclear structure and isospin and spin-isospin symmetries

    International Nuclear Information System (INIS)

    Krmpotic, F.

    1989-12-01

    Prominent features of the double beta decay processes are reviewed. Emphasis is placed on the neutrino masses and the quasiparticle random phase approximation (GRPA). The suppression mechanism for the ββ-decay transition rates, proposed by Vogel and Zirnbauer, is found to be closely related to the restoration of SU(4) symmetry. It is suggested that the extreme sensitivity of the ββ-decay amplitude on the proton-neutron coupling is a consequence of the explicit violation of the SU(4) symmetry and therefore an artifact of the model. A prescription is given for fixing this interaction strength within the GRPA itself, which in this way acquires predicting power on both single and double β-decay lifetimes. (author) [pt

  16. Concerning the variability of nuclear decay rates: Rebuttal of an article by Pomme et al. [1

    Science.gov (United States)

    Sturrock, P. A.; Steinitz, G.; Fischbach, E.

    2018-03-01

    Pomme et al. have recently analyzed one year of GSI (Geological Survey of Israel) radon data, and claimed that "GSI radon measurements are unsuited for studying the variability of decay constants because the data are strongly influenced by environmental conditions such as solar irradiance and rainfall" [1]. They also claim that "the existence of cyclic variations in the decay constant is refuted." We find that these claims are not supported by analysis of GSI data.

  17. Reply to ''Comment on enhancement of forbidden nuclear beta decay by high-intensity radio-frequency fields''

    International Nuclear Information System (INIS)

    Reiss, H.R.

    1984-01-01

    The negative conclusion in the Comment of Becker, Schlicher, and Scully about electromagnetic enhancement of beta decay is shown to be faulty. They have found an algebraic oversight in my paper, but correction of that oversight yields results strongly resembling the original. Becker, Schlicher, and Scully fail to find this. They then conduct an analysis which is highly implicit and incomplete. In attempting to analyze their very complicated expressions they claim not to find significant electromagnetic effects. Yet they also lose completely the electron retardation term of conventional forbidden beta decay. When they attempt to explain the difference between their results and mine, they misconstrue the momentum-translation technique and end up in a logical contradiction. They attempt also to apply a ''no-go'' theorem applicable only to plane-wave particles to my theory, which is built around the use of bound-state nuclear wave functions. This makes the no-go theorem inapplicable

  18. Co-ordination of the International Network of Nuclear Structure and Decay Data Evaluators; Summary Report of an IAEA Technical Meeting

    Energy Technology Data Exchange (ETDEWEB)

    Abriola, D.; Tuli, J.

    2009-03-23

    The IAEA Nuclear Data Section convened the 18th meeting of the International Network of Nuclear Structure and Decay Data Evaluators at the IAEA Headquarters, Vienna, 23 to 27 March 2009. This meeting was attended by 22 scientists from 14 Member States, plus IAEA staff, concerned with the compilation, evaluation and dissemination of nuclear structure and decay data. A summary of the meeting, recommendations/conclusions, data centre reports, and various proposals considered, modified and agreed by the participants are contained within this document. The International Network of Nuclear Structure and Decay Data (NSDD) Evaluators holds biennial meetings under the auspices of the IAEA, and consists of evaluation groups and data service centres in several countries. This network has the objective of providing up-to-date nuclear structure and decay data for all known nuclides by evaluating all existing experimental data. Data resulting from this international evaluation collaboration is included in the Evaluated Nuclear Structure Data File (ENSDF) and published in the journals Nuclear Physics A and Nuclear Data Sheets (NDS).

  19. Development of an international nuclear decay data and cross-section database. Summary report of an IAEA specialists' meeting, Vienna, 24-28 October 1994

    International Nuclear Information System (INIS)

    Lemmel, H.D.

    1994-12-01

    An IAEA Specialists' Meeting proposes procedures describing how an internationally accepted database of high-priority nuclear decay data and thermal neutron cross-sections can be developed through a network of experts coordinated by the IAEA Nuclear Data Section. (author)

  20. Comparisons of experimental beta-ray spectra important to decay heat predictions with ENSDF (Evaluated Nuclear Structure Data File) evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Dickens, J.K.

    1990-03-01

    Graphical comparisons of recently obtained experimental beta-ray spectra with predicted beta-ray spectra based on the Evaluated Nuclear Structure Data File are exhibited for 77 fission products having masses 79--99 and 130--146 and lifetimes between 0.17 and 23650 sec. The comparisons range from very poor to excellent. For beta decay of 47 nuclides, estimates are made of ground-state transition intensities. For 14 cases the value in ENSDF gives results in very good agreement with the experimental data. 12 refs., 77 figs., 1 tab.

  1. Comparisons of experimental beta-ray spectra important to decay heat predictions with ENSDF [Evaluated Nuclear Structure Data File] evaluations

    International Nuclear Information System (INIS)

    Dickens, J.K.

    1990-03-01

    Graphical comparisons of recently obtained experimental beta-ray spectra with predicted beta-ray spectra based on the Evaluated Nuclear Structure Data File are exhibited for 77 fission products having masses 79--99 and 130--146 and lifetimes between 0.17 and 23650 sec. The comparisons range from very poor to excellent. For beta decay of 47 nuclides, estimates are made of ground-state transition intensities. For 14 cases the value in ENSDF gives results in very good agreement with the experimental data. 12 refs., 77 figs., 1 tab

  2. The nuclear matrix elements of 0νββ decay and the NUMEN project at INFN-LNS

    Directory of Open Access Journals (Sweden)

    Cappuzzello F.

    2016-01-01

    Full Text Available An innovative technique to access the nuclear matrix elements entering the expression of the life time of the double beta decay by relevant cross sections measurements of double charge exchange reactions is proposed. A key aspect of the project is the use of the MAGNEX large acceptance magnetic spectrometer, for the detection of the ejectiles, and of the LNS K800 Superconducting Cyclotron (CS, for the acceleration of the required high resolution and low emittance heavyion beams, already in operation at INFN Laboratory Nazionali del Sud in Catania (Italy.

  3. Nuclear structure of tellurium 133 via beta decay and shell model calculations in the doubly magic tin 132 region

    International Nuclear Information System (INIS)

    Lane, S.M.

    1979-08-01

    An experimental investigation of the level structure of 133 Te was performed by spectroscopy of gamma-rays following the beta-decay of 2.7 min 133 Sb. Multiscaled gamma-ray singles spectra and 2.5 x 10 7 gamma-gamma coincidence events were used in the assignment of 105 of the approximately 400 observed gamma-rays to 133 Sb decay and in the construction of the 133 Te level scheme with 29 excited levels. One hundred twenty-two gamma-rays were identified as originating in the decay of other isotopes of Sb or their daughter products. The remaining gamma-rays were associated with the decay of impurity atoms or have as yet not been identified. A new computer program based on the Lanczos tridiagonalization algorithm using an uncoupled m-scheme basis and vector manipulations was written. It was used to calculate energy levels, parities, spins, model wavefunctions, neutron and proton separation energies, and some electromagnetic transition probabilities for the following nuclei in the 132 Sn region: 128 Sn, 129 Sn, 130 Sn, 131 Sn, 130 Sb, 131 Sb, 132 Sb, 133 Sb, 132 Te, 133 Te, 134 Te, 134 I, 135 I, 135 Xe, and 136 Xe. The results are compared with experiment and the agreement is generally good. For non-magic nuclei: the lg/sub 7/2/, 2d/sub 5/2/, 2d/sub 3/2/, 1h/sub 11/2/, and 3s/sub 1/2/ orbitals are available to valence protons and the 2d/sub 5/2/, 2d/sub 3/2/, 1h/sub 11/2/, and 3s/sub 1/2/ orbitals are available to valence neutron holes. The present CDC7600 computer code can accommodate 59 single particle states and vectors comprised of 30,000 Slater determinants. The effective interaction used was that of Petrovich, McManus, and Madsen, a modification of the Kallio-Kolltveit realistic force. Single particle energies, effective charges and effective g-factors were determined from experimental data for nuclei in the 132 Sn region. 116 references

  4. Summary Report of an IAEA Technical Meeting on Co-ordination of the International Network of Nuclear Structure and Decay Data Evaluators

    International Nuclear Information System (INIS)

    Abriola, D.; Nichols, A.L.; Tuli, J.K.

    2011-10-01

    The 19th meeting of the International Network of Nuclear Structure and Decay Data Evaluators was convened at the IAEA Headquarters, Vienna, from 4 to 8 April 2011, by the staff members of IAEA, Nuclear Data Section. This meeting was attended by 35 scientists from 20 Member States, plus IAEA staff, concerned with the compilation, evaluation and dissemination of nuclear structure and decay data. A summary of the meeting, data centre reports, various proposals considered, modified and agreed by the participants, and recommendations/conclusions are presented within this document. (author)

  5. Co-ordination of the International Network of Nuclear Structure and Decay Data Evaluators. Summary report of an IAEA technical meeting

    International Nuclear Information System (INIS)

    Abriola, D.; Tuli, J.K.

    2009-10-01

    The IAEA Nuclear Data Section convened the 18th meeting of the International Network of Nuclear Structure and Decay Data Evaluators at the IAEA Headquarters, Vienna, 23 to 27 March 2009. This meeting was attended by 22 scientists from 14 Member States, plus IAEA staff, concerned with the compilation, evaluation and dissemination of nuclear structure and decay data. A summary of the meeting, recommendations/conclusions, data centre reports, and various proposals considered, modified and agreed by the participants are contained within this document. (author)

  6. Nuclear structure effects in the exotic decay of $^{225}$Ac via $^{14}$C emission

    CERN Document Server

    Bonetti, R; Guglielmetti, A; Matheoud, R; Migliorino, C; Pasinetti, A L; Ravn, H L

    1993-01-01

    By using a $^{225}$Ac source produced at the electromagnetic separator Isolde we collected on our track-recording glass detectors 305 $^{14}$C events from the radioactive decays of $^{225}$Ac and its daughter $^{221}$Fr and obtained, for $^{225}$Ac, a branching ratio B($^{14}$C/$\\alpha$)=(6.0 $\\pm$ 1.3) x 10$^{-12}$. Our result suggests that such a decay from an odd proton nucleus is dominated by transition to the ground or to the first excited state of daughter nucleus.

  7. Estimation of delayed neutron emission probability by using the gross theory of nuclear β-decay

    International Nuclear Information System (INIS)

    Tachibana, Takahiro

    1999-01-01

    The delayed neutron emission probabilities (P n -values) of fission products are necessary in the study of reactor physics; e.g. in the calculation of total delayed neutron yields and in the summation calculation of decay heat. In this report, the P n -values estimated by the gross theory for some fission products are compared with experiment, and it is found that, on the average, the semi-gross theory somewhat underestimates the experimental P n -values. A modification of the β-decay strength function is briefly discussed to get more reasonable P n -values. (author)

  8. 0νββ-decay nuclear matrix elements with self-consistent short-range correlations

    International Nuclear Information System (INIS)

    Simkovic, Fedor; Faessler, Amand; Muether, Herbert; Rodin, Vadim; Stauf, Markus

    2009-01-01

    A self-consistent calculation of nuclear matrix elements of the neutrinoless double-beta decays (0νββ) of 76 Ge, 82 Se, 96 Zr, 100 Mo, 116 Cd, 128 Te, 130 Te, and 136 Xe is presented in the framework of the renormalized quasiparticle random phase approximation (RQRPA) and the standard QRPA. The pairing and residual interactions as well as the two-nucleon short-range correlations are for the first time derived from the same modern realistic nucleon-nucleon potentials, namely, from the charge-dependent Bonn potential (CD-Bonn) and the Argonne V18 potential. In a comparison with the traditional approach of using the Miller-Spencer Jastrow correlations, matrix elements for the 0νββ decay are obtained that are larger in magnitude. We analyze the differences among various two-nucleon correlations including those of the unitary correlation operator method (UCOM) and quantify the uncertainties in the calculated 0νββ-decay matrix elements.

  9. Nuclear Structure Effects in the Exotic Decay of $^{225}$Ac via $^{14}$C Emission

    CERN Multimedia

    2002-01-01

    % IS323 \\\\ \\\\ We propose to build at Isolde a high intensity $^{225}$Ac source by $\\beta$-decay of $^{225}$(Ra+Fr) beam, to be used at the superconducting spectrometer SOLENO of IPN-Orsay in order to study a possible fine structure in the spectrum of $^{14}$C ions spontaneously emitted by $^{225}$Ac.

  10. Scheme of fault tectonic and tectonic activity manifestation in the region of the Crimea nuclear power plant construction

    International Nuclear Information System (INIS)

    Pasynkov, A.L.

    1989-01-01

    Characteristic of fault tectonics and tectonic activity manifestation in the region of the Crimea nuclear power plant construction is presented. Mosaic-block structure of the area, predetermined by the development of diagonal systems of activated tectonic dislocations with different displacement amplitudes and different stratigraphic ranges of manifestation, was established. Strained-stressed state of the region is determined by the presence of the South-Azov zone of deep fault and Krasnogorsk-Samarlinks fault system. The presented scheme can be used as tectonic basis of seismogenic activity of the region

  11. Summary report of the technical meeting on intermediate-term nuclear data needs for medical applications: cross sections and decay data

    International Nuclear Information System (INIS)

    Nichols, Alan L.; Qaim, Syed M.; Noy, Roberto Capote

    2011-09-01

    A summary is given of a Technical Meeting on 'Intermediate-term Nuclear Data Needs for Medical Applications: Cross Sections and Decay Data'. Participants assessed and reviewed cross-section and decay data for an extensive number of radionuclides deemed as potentially suitable for application in nuclear medicine and radiotherapy. Technical discussions are described in this report, along with comprehensive listings and detailed recommendations for future work. Recommendations focused on cross-section studies for a reasonably wide range of targets and projectiles, along with decay data measurements for specific radionuclides. Cross-section and decay-data evaluations are also merited to ensure the necessary quality and consistency of the data to be assembled in an appropriate IAEA-NDS database. (author)

  12. Between atomic and nuclear physics: radioactive decays of highly-charged ions

    International Nuclear Information System (INIS)

    Atanasov, Dinko; Bosch, Fritz; Brandau, Carsten; Chen, Xiangcheng; Dillmann, Iris; Gao, Bingshui; Geissel, Hans; Hagmann, Siegbert; Hillenbrand, Pierre-Michel; Kozhuharov, Christophor; Litvinov, Sergey A; Litvinov, Yuri A; Münzenberg, Gottfried; Blaum, Klaus; Bühler, Paul; Faestermann, Thomas; Gernhäuser, Roman; Izumikawa, Takuji; Kurcewicz, Jan; Ma, Xinwen

    2015-01-01

    Highly charged radioactive ions can be stored for extended periods of time in storage rings which allows for precision measurements of their decay modes. The straightforward motivation for performing such studies is that fully ionised nuclei or few-electron ions can be viewed as clean quantum-mechanical systems, in which the interactions of the many electrons can be either excluded or treated precisely. Thus, the influence of the electron shell on the decay probability can be investigated. Another important motivation is stellar nucleosynthesis, which proceeds at high temperatures and the involved atoms are therefore highly ionised. Presented here is a compact review of the relevant experiments conducted at heavy-ion storage rings. Furthermore, we outline the perspectives for future experiments at new-generation storage-ring facilities. (paper)

  13. Evidence for the emission of a massive neutrino in nuclear beta decay

    International Nuclear Information System (INIS)

    Norman, E.B.; Sur, B.; Lesko, K.T.; Larimer, R.M.; Witort, J.T.; Haller, E.E.; California Univ., Berkeley, CA

    1990-10-01

    We have studied the β-spectrum of 14 C using a germanium detector containing a crystal with 14 C dissolved in it. We find a feature in the β-spectrum 17 keV below the endpoint which can be explained by the hypothesis that there is a heavy neutrino emitted in the β-decay of 14 C with a mass of 17 ± 2 keV and an emission probability of 1.40 ± 0.45%. In addition, we have studied the inner bremsstrahlung spectrum of 55 Fe and also find indications of the emission of a ∼ 17-keV neutrino. These results are consistent with observations of similar anomalies in the β-decays of 3 H and 35 S. 29 refs., 7 figs

  14. Fission yields data generation and benchmarks of decay heat estimation of a nuclear fuel

    Directory of Open Access Journals (Sweden)

    Gil Choong-Sup

    2017-01-01

    Full Text Available Fission yields data with the ENDF-6 format of 235U, 239Pu, and several actinides dependent on incident neutron energies have been generated using the GEF code. In addition, fission yields data libraries of ORIGEN-S, -ARP modules in the SCALE code, have been generated with the new data. The decay heats by ORIGEN-S using the new fission yields data have been calculated and compared with the measured data for validation in this study. The fission yields data ORIGEN-S libraries based on ENDF/B-VII.1, JEFF-3.1.1, and JENDL/FPY-2011 have also been generated, and decay heats were calculated using the ORIGEN-S libraries for analyses and comparisons.

  15. Search for non Standard Model physics in nuclear-$\\beta$ decay with the WITCH experiment

    CERN Document Server

    Coeck, Sam

    In this work the WITCH experiment, which primarily aims for precision measurements of the beta-neutrino-angular correlation coefficient, is presented in detail. First a theoretical description of the beta-decay process is presented and it was shown how measurements of correlation coefficients can reveal the exact nature of the weak interaction. Although many experiments have already been conducted in this field, there is still considerable room for additional phenomena that are not included in the Standard Model. At WITCH the beta-neutrino-angular correlation coefficient will be obtained from precision measurements of the energy spectrum of the nuclei that recoil after beta-decay, thus avoiding the need to observe the neutrino. To enable a measurement of the recoiling ions, the setup uses a combination of two electromagnetic Penning traps and a retardation spectrometer. This allows one to construct the scattering free radioactive source that is needed as the recoiling ions have only a very small kinetic energ...

  16. NESSY, a relational PC database for nuclear structure and decay data

    International Nuclear Information System (INIS)

    Boboshin, I.N.; Varlamov, V.V.; Trukhanov, S.K.

    1994-11-01

    The universal relational database NESSY (New ENSDF Search SYstem) based on the international ENSDF system (Evaluated Nuclear Structure Data File) is described. NESSY, which was developed for IBM compatible PC, provides high efficiency processing of ENSDF information for searches and retrievals of nuclear physics data. The principle of the database development and examples of applications are presented. (author)

  17. The place of a nuclear manpower policy in an overall training scheme

    International Nuclear Information System (INIS)

    Bauer, Et.

    1980-01-01

    Any country starting out on a nuclear power programme will have to make a considerable effort in terms of teaching. A policy properly pursued will gear the whole of the technical education system to nuclear requirements, thereby benefiting the national industry as a whole. Emphasis should be given to the training and social-financial status of technicians who, as opposed to engineers and research workers, can only be trained abroad with great difficulty. One of the major benefits of a nuclear power industry will be that it appreciably raises the technical level of the country concerned. (author)

  18. Nuclear Security Education in “non-Nuclear” Countries – Inseparable Component of Global Nuclear Security Scheme. Example of Montenegro

    International Nuclear Information System (INIS)

    Jovanovic, S.

    2014-01-01

    • Global regime of nuclear security cannot be complete and functional if all countries are not involved; • Apart from the fact that developed nuclear countries are crucial in this sense (and determining the system), due attention should be paid to small, developing, “nonnuclear” ones; • Small problems in big countries are often big problems in small countries – so it is with HRD in nuclear related fields; • Everything is based on competence, with education being fundamental for building it up; • To that aim, the role of universities is of utmost importance, while networking is another corner stone; • Experience of Montenegro, perhaps exemplary in the above context, is discussed. (author)

  19. Retrieval transmutation and decay process of nuclides using nuclear reaction database on internet

    International Nuclear Information System (INIS)

    Fujita, Mitsutane; Utsumi, Misako; Noda, Tetsuji

    1999-01-01

    In the data system for alloy design and selection of materials used in various nuclear reactors, huge material databases and several kinds of tools for data analysis or simulation code of the phenomena under neutron irradiation are required. A nuclear reaction database system based on the data of FENDL-II on the Internet has been developed in NRIM site of Data-Free-Way'. The user interface in this database was made for the retrieval of the necessary data and for the expression of the graph of the relation between the nuclear energy spectrum of neutron and neutron capture cross section. It is indicated that using the database, the possibility of chemical compositional change and radioactivity in a material caused by nuclear reactions can be easily retrieved, though the evaluation is qualitatively. (author)

  20. Moessbauer study on the aftereffects of nuclear decay in sulphate hydrates

    International Nuclear Information System (INIS)

    Kobayashi, Takayuki

    1987-01-01

    The anomalous states produced by the electron capture decay of 57 Co in FeSO 4 .H 2 O, FeSO 4 .7H 2 O, CoSO 4 .7H 2 O, MgSO 4 .H 2 O, MgSO 4 .7H 2 O and ZnSO 4 .7H 2 O are observed using Moessbauer emission spectroscopy. The characteristic aspects of the Moessbauer spectra are described in terms of the difference in ionic radius and of the structure and properties of the sample crystals. (orig.)

  1. Integrated scheme of long-term for spent fuel management of power nuclear reactors

    International Nuclear Information System (INIS)

    Ramirez S, J. R.; Palacios H, J. C.; Martinez C, E.

    2015-09-01

    After of irradiation of the nuclear fuel in the reactor core, is necessary to store it for their cooling in the fuel pools of the reactor. This is the first step in a processes series before the fuel can reach its final destination. Until now there are two options that are most commonly accepted for the end of the nuclear fuel cycle, one is the open nuclear fuel cycle, requiring a deep geological repository for the fuel final disposal. The other option is the fuel reprocessing to extract the plutonium and uranium as valuable materials that remaining in the spent fuel. In this study the alternatives for the final part of the fuel cycle, which involves the recycling of plutonium and the minor actinides in the same reactor that generated them are shown. The results shown that this is possible in a thermal reactor and that there are significant reductions in actinides if they are recycled into reactor fuel. (Author)

  2. Study of nuclear dependence of production and decay of $\\phi$ meson in 12-GeV p+A interaction

    CERN Document Server

    Yokkaichi, S

    2000-01-01

    We have observed phi mesons in the phi to K/sup +/K/sup -/ decay mode in 12-GeV p+A interaction with the newly constructed spectrometer at the primary beam line in the KEK Proton Synchrotron. The kinematical region of the observed phi mesons covers 1 to 3 in beta /sub gamma lab/ where modification of phi meson in nuclear matter is expected to be visible. The shape of the invariant mass spectra of the observed phi mesons are consistent with that observed in free space within the experimental errors. The mass number dependence of the production cross section follows A/sup a/ ( alpha =0.98+or-0.10) between carbon and lead nuclei. No significant p/sub T/ dependence has been observed on the alpha parameter. (27 refs).

  3. Report on the IAEA coordinated research program on the measurement and evaluation of transactinium isotope nuclear decay data

    International Nuclear Information System (INIS)

    Reich, C.W.

    1979-01-01

    As one result of the First IAEA Advisory Group Meeting on Transactinium Isotope Nuclear Data, held in November 1975 at Karlsruhe, an IAEA Coordinated Research Program was set up to address certain identified actinide-isotope decay-data needs in reactor technology. At present, laboratories from five nations are involved in this effort. This paper gives an overview of this program, including its origin and the present status of the measurements being carried out. The current status of the actinide-nuclide half-life, spontaneous-fission branching ratio, α-intensity and γ-intensity data of concern to the Coordinated Research Program is presented and briefly discussed. 3 figures, 9 tables

  4. The Decay of Communism: Managing Spent Nuclear Fuel in the Soviet Union, 1937-1991

    International Nuclear Information System (INIS)

    Hoegselius, Per

    2010-09-01

    The historical evolution of spent nuclear fuel (SNF) decision-making in Western Europe and North America is already fairly well-known. For the former socialist countries of Eastern Europe, and in particular the Soviet Union, we know less. There have recently been several good studies of Soviet nuclear power history (e.g. Schmid 2004, 2006, Josephson 2005), but none of them has gone into any depth when it comes to SNF, but rather focused on nuclear power reactors, public acceptance, the role of the media, etc. There are also several good overviews available that problematize the radioactive legacy of the Soviet Union, including the SNF and waste issue, but these studies do not address the historical dynamics and evolution of SNF management over a longer period of time; in other words, they fail to explain how and why the present state of affairs have actually come into being. The aim of this paper is to provide historical insight into the dynamics of SNF decision-making in the Soviet Union, from the origins of nuclear engineering in the 1930s to the collapse of the country in 1991. The nuclear fuel system can be described as a large technical system with a variety of interrelated components. The system is 'large' both because it involves key links between geographically disperse activities, and because it involves a variety of technologies, organizations and people that influence the dynamics and evolution of the system. Soviet SNF history is of particular interest in this context, with a nuclear fuel system that was the most complex in the world. The USSR was a pioneer within nuclear power and developed a variety of reactor designs and technologies for uranium mining, conversion and enrichment, as well as for transport, treatment, storage and reprocessing of spent nuclear fuel. It explored both military and civil uses of the atom, and an enormous amount of people and organizations were involved in realizing highly ambitious nuclear programmes. The USSR is of

  5. The Decay of Communism: Managing Spent Nuclear Fuel in the Soviet Union, 1937-1991

    Energy Technology Data Exchange (ETDEWEB)

    Hoegselius, Per (History of Science and Technology, Royal Inst. of Technology, Stockholm (Sweden)), e-mail: perho@kth.se

    2010-09-15

    The historical evolution of spent nuclear fuel (SNF) decision-making in Western Europe and North America is already fairly well-known. For the former socialist countries of Eastern Europe, and in particular the Soviet Union, we know less. There have recently been several good studies of Soviet nuclear power history (e.g. Schmid 2004, 2006, Josephson 2005), but none of them has gone into any depth when it comes to SNF, but rather focused on nuclear power reactors, public acceptance, the role of the media, etc. There are also several good overviews available that problematize the radioactive legacy of the Soviet Union, including the SNF and waste issue, but these studies do not address the historical dynamics and evolution of SNF management over a longer period of time; in other words, they fail to explain how and why the present state of affairs have actually come into being. The aim of this paper is to provide historical insight into the dynamics of SNF decision-making in the Soviet Union, from the origins of nuclear engineering in the 1930s to the collapse of the country in 1991. The nuclear fuel system can be described as a large technical system with a variety of interrelated components. The system is 'large' both because it involves key links between geographically disperse activities, and because it involves a variety of technologies, organizations and people that influence the dynamics and evolution of the system. Soviet SNF history is of particular interest in this context, with a nuclear fuel system that was the most complex in the world. The USSR was a pioneer within nuclear power and developed a variety of reactor designs and technologies for uranium mining, conversion and enrichment, as well as for transport, treatment, storage and reprocessing of spent nuclear fuel. It explored both military and civil uses of the atom, and an enormous amount of people and organizations were involved in realizing highly ambitious nuclear programmes. The USSR is

  6. ENDF/B-VII.1 Nuclear Data for Science and Technology: Cross Sections, Covariances, Fission Product Yields and Decay Data

    Energy Technology Data Exchange (ETDEWEB)

    Chadwick, M.B.; Herman, M.; Author(s): Chadwick,M.B.; Herman,M.; Oblozinsky,P.; Dunn,M.E.; Danon,Y.; Kahler,A.C.; Smith,D.L.; Pritychenko,B.; Arbanas,G.; Arcilla,R.; Brewer,R.; Brown,D.A.; Capote,R.; Carlson,A.D.; Cho,Y.S.; Derrien,H.; Guber,K.; Hale,G.M.; Hoblit,S.; Holloway,S.: Johnson,T.D.; Kawano,T.; Kiedrowski,B.C.; Kim,H.; Kunieda,S.; Larson,N.M.; Leal,L.; Lestone,J.P.; Little,R.C.; McCutchan,E.A.; MacFarlane,R.E.; MacInnes,M.; Mattoon,C.M.; McKnight,R.D.; Mughabghab,S.F.; Nobre,G.P.A.; Palmiotti,G.; Palumbo,A.; Pigni,M.T.; Pronyaev,V.G.; Sayer,R.O.; Sonzogni,A.A.; Summers,N.C.; Talou,P.; Thompson,I.J.; Trkov,A.; Vogt,R.L.; van der Marck,S.C.; Wallner,A.; White,M.C.; Wiarda,D.; Young,P.G.

    2011-12-01

    The ENDF/B-VII.1 library is our latest recommended evaluated nuclear data file for use in nuclear science and technology applications, and incorporates advances made in the five years since the release of ENDF/B-VII.0. These advances focus on neutron cross sections, covariances, fission product yields and decay data, and represent work by the US Cross Section Evaluation Working Group (CSEWG) in nuclear data evaluation that utilizes developments in nuclear theory, modeling, simulation, and experiment. The principal advances in the new library are: (1) An increase in the breadth of neutron reaction cross section coverage, extending from 393 nuclides to 423 nuclides; (2) Covariance uncertainty data for 190 of the most important nuclides, as documented in companion papers in this edition; (3) R-matrix analyses of neutron reactions on light nuclei, including isotopes of He, Li, and Be; (4) Resonance parameter analyses at lower energies and statistical high energy reactions for isotopes of Cl, K, Ti, V, Mn, Cr, Ni, Zr and W; (5) Modifications to thermal neutron reactions on fission products (isotopes of Mo, Tc, Rh, Ag, Cs, Nd, Sm, Eu) and neutron absorber materials (Cd, Gd); (6) Improved minor actinide evaluations for isotopes of U, Np, Pu, and Am (we are not making changes to the major actinides {sup 235,238}U and {sup 239}Pu at this point, except for delayed neutron data and covariances, and instead we intend to update them after a further period of research in experiment and theory), and our adoption of JENDL-4.0 evaluations for isotopes of Cm, Bk, Cf, Es, Fm, and some other minor actinides; (7) Fission energy release evaluations; (8) Fission product yield advances for fission-spectrum neutrons and 14 MeV neutrons incident on {sup 239}Pu; and (9) A new decay data sublibrary. Integral validation testing of the ENDF/B-VII.1 library is provided for a variety of quantities: For nuclear criticality, the VII.1 library maintains the generally-good performance seen for VII.0

  7. Method and device to remove the decay heat produced in the core of a nuclear reactor

    International Nuclear Information System (INIS)

    Loimann, E.; Reutler, H.

    1977-01-01

    For decay haet removal of the HTGR the heat absorbed by the top reflector is discharged by means of heat exchangers. For this purpose the heat exchangers are arranged between the top bricks consisting of graphite blocks. By convection or forced circulation with the aid of pumps the liquid coolant is flowing in a cycle between the individual heat exchangers connected in parallel and a heat sink arranged outside the containment. The distributing and collection pipes are mounted between the upper and lower thermal shield. The heat exchanger compartments themselves consist of double-walled hollow bodies with a disc-shaped section and a columnar part extending from there to one side respectively. (RW) [de

  8. Complex fragment emission in binary and multifragment decay of very hot nuclear systems

    Energy Technology Data Exchange (ETDEWEB)

    Moretto, L.G.; Blumenfeld, Y.; Delis, D.; Wozniak, G.J.

    1990-07-01

    Low-energy compound nucleus emission of complex fragments in the reaction {sup 63}Cu + {sup 12}C is used to infer the associated ridge-line potential. Compound binary emission of complex fragments at higher energies is illustrated for a variety of reactions. Complex fragment emission from 35 and 40 MeV/N {sup 139}La + {sup 12}C, {sup 27}Al, {sup 40}Ca and {sup 51}V reactions has been studied. Multifragment events from these reactions were assigned to sources characterized by their energy and mass through the incomplete-fusion-model kinematics. Excitation functions for the various multifragment channels appear to be nearly independent of the system and bombarding energy. Preliminary comparisons of the data with sequential-statistical-decay calculations are discussed.

  9. Exact calculations of nuclear-recoil energies from prompt gamma decays resulting from neutron capture

    Energy Technology Data Exchange (ETDEWEB)

    Kinney, J.H.

    1981-07-20

    The results of an accurate determination of the recoil spectrum from (n, ..gamma..) reactions in molybdenum are presented. The recoil spectrum has been calculated from nuclear level structure data and measured branching ratios. Angular correlations between successive gammas have been accounted for using the standard theoretical techniques of Racah algebra and the density matrix formalism.

  10. Measurements of observables in the pion-nucleon system, nuclear a- dependence of heavy quark production and rare decays of D and B mesons

    International Nuclear Information System (INIS)

    Sadler, M.E.; Isenhower, L.D.

    1992-01-01

    This report discusses research on the following topics: pion-nucleon interactions; detector tomography facility; nuclear dependence of charm and beauty quark production and a study of two-prong decays of neutral D and B mesons; N* collaboration at CEBAF; and pilac experiments

  11. Measurements of observables in the pion-nucleon system, nuclear a- dependence of heavy quark production and rare decays of D and B mesons

    Energy Technology Data Exchange (ETDEWEB)

    Sadler, M.E.; Isenhower, L.D.

    1992-02-15

    This report discusses research on the following topics: pion-nucleon interactions; detector tomography facility; nuclear dependence of charm and beauty quark production and a study of two-prong decays of neutral D and B mesons; N* collaboration at CEBAF; and pilac experiments. (LSP)

  12. Nuclear Data Sheets for A=213

    International Nuclear Information System (INIS)

    Basunia, M.S.

    2007-01-01

    Evaluated spectroscopic data and level schemes from radioactive decay and nuclear reaction studies are presented for all nuclei with mass number A=213. This evaluation for A=213 supersedes the earlier one by Y. A. Akovali (1992Ak01), published in Nuclear Data Sheets 66, 237 (1992)

  13. Nuclear Data Sheets for A=213

    Energy Technology Data Exchange (ETDEWEB)

    Basunia, M. S.

    2007-03-01

    Evaluated spectroscopic data and level schemes from radioactive decay and nuclear reaction studies are presented for all nuclei with mass number A=213. This evaluation for A=213 supersedes the earlier one by Y. A. Akovali (1992Ak01), published in Nuclear Data Sheets 66, 237 (1992).

  14. Role of various Dirac covariants in the BS wave functions in decay constant calculations of pseudoscalar mesons using a power counting scheme

    International Nuclear Information System (INIS)

    Bhatnagar, S.; Mahecha, J.

    2008-09-01

    We have employed the framework of Bethe-Salpeter equation under Covariant Instantaneous Ansatz to calculate the leptonic decay constants of unequal mass pseudoscalar mesons. In the Dirac structure of BS wave function, the covariants are incorporated from their complete set in accordance with a recently proposed power counting rule, order-by-order in powers of inverse of meson mass. The decay constants are calculated incorporating both Leading Order (LO) as well as Next-to-leading Order (NLO) Dirac covariants. The contribution of both LO as well as NLO covariants to decay constants are studied in detail in this paper. The results are found to improve dramatically, and hence validating the power counting rule which also provides a practical means of incorporating Dirac covariants in the BS wave function of a hadron. (author)

  15. Effects of alpha decays on nuclear waste glasses, simulation through atomistic models

    International Nuclear Information System (INIS)

    Ghaleb, D.; Delaye, J.M.

    1997-01-01

    In a simplified (SiO 2 , B 2 O 3 , Na 2 O 3 , Al 2 O 3 , ZrO 2 ) nuclear glass we have simulated, by Molecular Dynamics simulations, the effects of displacement cascades created by the slowing-down of the recoil nucleus. The methodology employed to construct and validate the used Molecular Dynamics model representing the basis matrix of the 'light-water' French nuclear glass (R77) and the manner which are simulated atomic displacements are described. Although the energies given to recoil nucleus were relatively low (≤ 1/10 of actual energies) the study has yielded a number of interesting results. Notably we have: - identified the main mechanisms responsible for the depolymerization of the network; - observed, at the atomic level, the kinetic of the structure evolution; - detailed the behavior and displacement mechanisms of every atomic species during the cascade sequences; - made a link with the experimentation through the calculation of some physical properties. (authors)

  16. Beta decays of 126Cd and 126In to levels in 126In and 126Sn

    International Nuclear Information System (INIS)

    Gartner, M.L.

    1979-01-01

    A study of the beta decays of 126 Cd and 126 In using the TRISTAN on-line isotope separator facility is reported. Gamma-ray singles measurements were made for both decays usng Ge(Li) and LEPS (low energy photon spectrometer) detectors. In addition, gamma--gamma coincidence measurements and gamma multiscale measurements were made for both decays using Ge(Li) detectors. The half-life for 126 Cd was determined to be 0.506 +- 0.015 sec., and the half-lives for the low- and high-spin 126 In isomers were determined to be 1.83 +- 0.11 sec. and 1.96 +- 0.10 sec., respectively. A total of 11 gamma rays were observed in the decay of 126 Cd, and all but one were placed in a level scheme for 126 In. A total of 48 gamma rays were observed in the decay of the low- and high-spin 126 In isomers and all were placed in a level scheme for 126 Sn. Spin and parity assignments were deduced, whenever possible, on the basis of logft values and gamma decay selection rules. The 126 In decay schemes (one has been proposed for each isomer) are compared with earlier decay studies and with results from 124 Sn(t,p) 126 Sn reaction experiments. The systematics associated with the level schemes are discussed and a comparison is made with the nuclear shell model. 49 references

  17. Build-up and decay of fuel actinides in the fuel cycle of nuclear reactors

    International Nuclear Information System (INIS)

    Tasaka, Kanji; Kikuchi, Yasuyuki; Shindo, Ryuichi; Yoshida, Hiroyuki; Yasukawa, Shigeru

    1976-05-01

    For boiling water reactors, pressurized light-water reactors, pressure-tube-type heavy water reactors, high-temperature gas-cooled reactors, and sodium-cooled fast breeder reactors, uranium fueled and mixed-oxide fueled, each of 1000 MWe, the following have been studied: (1) quantities of plutonium and other fuel actinides built up in the reactor, (2) cooling behaviors of activities of plutonium and other fuel actinides in the spent fuels, and (3) activities of plutonium and other fuel actinides in the high-level reprocessing wastes as a function of storage time. The neutron cross section and decay data of respective actinide nuclides are presented, with their evaluations. For effective utilization of the uranium resources and easy reprocessing and high-level waste management, a thermal reactor must be fueled with uranium; the plutonium produced in a thermal reactor should be used in a fast reactor; and the plutonium produced in the blanket of a fast reactor is more appropriate for a fast reactor than that from a thermal reactor. (auth.)

  18. A laboratory scale investigation scheme to prognosticate corrosion characteristics of nuclear power plant systems

    International Nuclear Information System (INIS)

    Szabo, I.

    1983-01-01

    To determine the corrosion properties of system components in primary and secondary circuits of nuclear power plants long-term investigations are needed and experimental loops are required containing all the construction materials of the real system with operation parameters matching that of the power station as close as possible. A different approach should be looked for when response time of some days or weeks can not be exceeded. Comparative investigations were carried out to evaluate a fast method to determine corrosion characteristics of multi-component systems using the model samples representing typical components of a nuclear power plant. In the usual way corrosion rates were determined in experimental runs of several weeks in primary coolant solutions at the nominal operational temperature of 90-100 deg. C in the presence and in the absence of oxygen. On the other hand electrode potentials were measured in the coolant, while variations in surface and ''near surface'' elemental composition of the model samples during corrosion as well as the corrosion rate was measured in diluted decontamination solution. Comparing the results it could be established, that the proposed method can not offer absolute values of the corrosion rate but it can be used to determine the relative corrosion resistance of the system components and to prognosticate possible corrosion-incompatibility, and this can be done within a couple of hours. (author)

  19. Development and validation of calculation schemes dedicated to the interpretation of small reactivity effects for nuclear data improvement

    International Nuclear Information System (INIS)

    Gruel, A.

    2011-01-01

    Reactivity measurements by the oscillation technique, as those performed in the Minerve reactor, enable to access various neutronic parameters on materials, fuels or specific isotopes. Usually, expected reactivity effects are small, about ten pcm at maximum. Then, the modeling of these experiments should be very precise, to obtain reliable feedback on the pointed parameters. Especially, calculation biases should be precisely identified, quantified and reduced to get precise information on nuclear data. The goal of this thesis is to develop a reference calculation scheme, with well quantified uncertainties, for in-pile oscillation experiments. In this work are presented several small reactivity calculation methods, based on deterministic and/or stochastic calculation codes. Those method are compared thanks to a numerical benchmark, against a reference calculation. Three applications of these methods are presented here: a purely deterministic calculation with exact perturbation theory formalism is used for the experimental validation of fission product cross sections, in the frame of reactivity loss studies for irradiated fuel; an hybrid method, based on a stochastic calculation and the exact perturbation theory is used for the readjustment of nuclear data, here 241 Am; and a third method, based on a perturbative Monte Carlo calculation, is used in a conception study. (author) [fr

  20. Auxiliary System Load Schemes in Large Thermal and Nuclear Power Plants

    International Nuclear Information System (INIS)

    Kuzle, I.; Bosnjak, D.; Pandzic, H.

    2010-01-01

    Uninterrupted auxiliary system power supply in large power plants is a key factor for normal operation, transient states, start-ups and shutdowns and particularly during fault conditions. Therefore, there are many challenges in designing the main electrical system as well as the auxiliary systems power supply. Depending upon the type of fuel used and the environmental control system required, a thermal power plant may consume as much as 10% of its total generation for auxiliary power, while a nuclear power plant may require only 4 - 6% auxiliaries. In general, the larger the power generating plant, the higher the voltage selected for the AC auxiliary electric system. Most stations in the 75 to 500 MW range utilize 4,2 kV as the base auxiliary system voltage. Large generating stations 500 - 1000 MW and more use voltage levels of 6,9 kV and more. Some single dedicated loads such as electric driven boiler feed pumps are supplied ba a 13,8 kV bus. While designing the auxiliary electric system, the following areas must be considered: motor starting requirements, voltage regulation requirements, short-circuit duty requirements, economic considerations, reliability and alternate sources. Auxiliary power supply can't be completely generalized and each situation should be studied on its own merits to determine the optimal solution. Naturally, nuclear power plants have more reliability requirements and safety design criteria. Main coolant-pump power supply and continuity of service to other vital loads deserve special attention. This paper presents an overview of some up-to-date power plant auxiliary load system concepts. The main types of auxiliary loads are described and the electric diagrams of the modern auxiliary system supply concepts are given. Various alternative sources of auxiliary electrical supply are considered, the advantages and disadvantages of these are compared and proposals are made for high voltage distribution systems around the thermal and nuclear plant

  1. Brief of the joint research with universities, etc. for 2002. Except the research by the JNC cooperative research scheme on the nuclear fuel cycle

    International Nuclear Information System (INIS)

    2003-09-01

    The Japan Nuclear Cycle Development Institute (JNC) promote the basic and fundamental research in relation to the research and development projects of JNC through collaboration with universities and other research institutes (referred to as 'universities, etc.' below). This report includes a summary of the results of the research carried out in fiscal year 2002 on 15 joint researches with universities, etc. In addition, this report removes the research by the JNC Cooperative Research Scheme on the Nuclear Fuel Cycle. (author)

  2. ENDF/B-VII.1 Nuclear Data for Science and Technology: Cross Sections, Covariances, Fission Product Yields and Decay Data

    Energy Technology Data Exchange (ETDEWEB)

    Chadwick, M. B. [Los Alamos National Laboratory (LANL); Herman, Micheal W [Brookhaven National Laboratory (BNL); Oblozinsky, Pavel [Brookhaven National Laboratory (BNL); Dunn, Michael E [ORNL; Danon, Y. [Rensselaer Polytechnic Institute (RPI); Kahler, A. [Los Alamos National Laboratory (LANL); Smith, Donald L. [Argonne National Laboratory (ANL); Pritychenko, B [Brookhaven National Laboratory (BNL); Arbanas, Goran [ORNL; Arcilla, r [Brookhaven National Laboratory (BNL); Brewer, R [Los Alamos National Laboratory (LANL); Brown, D A [Brookhaven National Laboratory (BNL); Capote, R. [International Atomic Energy Agency (IAEA); Carlson, A. D. [National Institute of Standards and Technology (NIST); Cho, Y S [Korea Atomic Energy Research Institute; Derrien, Herve [ORNL; Guber, Klaus H [ORNL; Hale, G. M. [Los Alamos National Laboratory (LANL); Hoblit, S [Brookhaven National Laboratory (BNL); Holloway, Shannon T. [Los Alamos National Laboratory (LANL); Johnson, T D [Brookhaven National Laboratory (BNL); Kawano, T. [Los Alamos National Laboratory (LANL); Kiedrowski, B C [Los Alamos National Laboratory (LANL); Kim, H [Korea Atomic Energy Research Institute; Kunieda, S [Los Alamos National Laboratory (LANL); Larson, Nancy M [ORNL; Leal, Luiz C [ORNL; Lestone, J P [Los Alamos National Laboratory (LANL); Little, R C [Los Alamos National Laboratory (LANL); Mccutchan, E A [Brookhaven National Laboratory (BNL); Macfarlane, R E [Los Alamos National Laboratory (LANL); MacInnes, M [Los Alamos National Laboratory (LANL); Matton, C M [Lawrence Livermore National Laboratory (LLNL); Mcknight, R D [Argonne National Laboratory (ANL); Mughabghab, S F [Brookhaven National Laboratory (BNL); Nobre, G P [Brookhaven National Laboratory (BNL); Palmiotti, G [Idaho National Laboratory (INL); Palumbo, A [Brookhaven National Laboratory (BNL); Pigni, Marco T [ORNL; Pronyaev, V. G. [Institute of Physics and Power Engineering (IPPE), Obninsk, Russia; Sayer, Royce O [ORNL; Sonzogni, A A [Brookhaven National Laboratory (BNL); Summers, N C [Lawrence Livermore National Laboratory (LLNL); Talou, P [Los Alamos National Laboratory (LANL); Thompson, I J [Lawrence Livermore National Laboratory (LLNL); Trkov, A. [Jozef Stefan Institute, Slovenia; Vogt, R L [Lawrence Livermore National Laboratory (LLNL); Van der Marck, S S [Nucl Res & Consultancy Grp, Petten, Netherlands; Wallner, A [University of Vienna, Austria; White, M C [Los Alamos National Laboratory (LANL); Wiarda, Dorothea [ORNL; Young, P C [Los Alamos National Laboratory (LANL)

    2011-01-01

    The ENDF/B-VII.1 library is our latest recommended evaluated nuclear data file for use in nuclear science and technology applications, and incorporates advances made in the five years since the release of ENDF/B-VII.0. These advances focus on neutron cross sections, covariances, fission product yields and decay data, and represent work by the US Cross Section Evaluation Working Group (CSEWG) in nuclear data evaluation that utilizes developments in nuclear theory, modeling, simulation, and experiment. The principal advances in the new library are: (1) An increase in the breadth of neutron reaction cross section coverage, extending from 393 nuclides to 423 nuclides; (2) Covariance uncertainty data for 190 of the most important nuclides, as documented in companion papers in this edition; (3) R-matrix analyses of neutron reactions on light nuclei, including isotopes of He; Li, and Be; (4) Resonance parameter analyses at lower energies and statistical high energy reactions for isotopes of Cl; K; Ti, V, Mn, Cr, Ni, Zr and W; (5) Modifications to thermal neutron reactions on fission products (isotopes of Mo, Tc, Rh, Ag, Cs, Nd, Sm, Eu) and neutron absorber materials (Cd, Gd); (6) Improved minor actinide evaluations for isotopes of U, Np, Pu, and Am (we are not making changes to the major actinides (235,238)U and (239)Pu at this point, except for delayed neutron data and covariances, and instead we intend to update them after a further period of research in experiment and theory), and our adoption of JENDL-4.0 evaluations for isotopes of Cm, Bk, Cf, Es; Fm; and some other minor actinides; (7) Fission energy release evaluations; (8) Fission product yield advances for fission-spectrum neutrons and 14 MeV neutrons incident on (239)Pu; and (9) A new decay data sublibrary. Integral validation testing of the ENDF/B-VII.1 library is provided for a variety of quantities: For nuclear criticality, the VII.1 library maintains the generally-good performance seen for VII.0 for a wide

  3. Structure and reconstitution of yeast Mpp6-nuclear exosome complexes reveals that Mpp6 stimulates RNA decay and recruits the Mtr4 helicase

    Energy Technology Data Exchange (ETDEWEB)

    Wasmuth, Elizabeth V. [Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, United States; Zinder, John C. [Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, United States; Tri-Institutional Training Program in Chemical Biology, Memorial Sloan Kettering Cancer Center, New York, United States; Zattas, Dimitrios [Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, United States; Das, Mom [Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, United States; Lima, Christopher D. [Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, United States; Howard Hughes Medical Institute, Memorial Sloan Kettering Cancer Center, New York, United States

    2017-07-25

    Nuclear RNA exosomes catalyze a range of RNA processing and decay activities that are coordinated in part by cofactors, including Mpp6, Rrp47, and the Mtr4 RNA helicase. Mpp6 interacts with the nine-subunit exosome core, while Rrp47 stabilizes the exoribonuclease Rrp6 and recruits Mtr4, but it is less clear if these cofactors work together. Using biochemistry with Saccharomyces cerevisiae proteins, we show that Rrp47 and Mpp6 stimulate exosome-mediated RNA decay, albeit with unique dependencies on elements within the nuclear exosome. Mpp6-exosomes can recruit Mtr4, while Mpp6 and Rrp47 each contribute to Mtr4-dependent RNA decay, with maximal Mtr4-dependent decay observed with both cofactors. The 3.3 Å structure of a twelve-subunit nuclear Mpp6 exosome bound to RNA shows the central region of Mpp6 bound to the exosome core, positioning its Mtr4 recruitment domain next to Rrp6 and the exosome central channel. Genetic analysis reveals interactions that are largely consistent with our model.

  4. ORYX-E: ORIGEN yields and cross sections, nuclear transmutation and decay data from ENDF/B. [In FORTRAN IV for IBM 360

    Energy Technology Data Exchange (ETDEWEB)

    1976-01-01

    ORYX-E increases the versatility of CCC-217/ORIGEN, the isotope generation and depletion code package, by providing basic cross section and decay information for light element, fission-product, and actinide nuclides. This data library package results from data compiled for ORNL Chemical Technology Division's work with ORIGEN and from a 2-year effort of the Cross Section Evaluation Working Group (CSEWG) Fission Product Task Force. The data are generated from ENDF/B-IV, and are formated for input to the ORIGEN (CCC-217) code. Applications include calculations for waste projection, decay heat, nuclear safeguards, and fuel cycle economics. (RWR)

  5. ENSL and CDRL: Evaluated nuclear structure libraries

    International Nuclear Information System (INIS)

    Howerton, R.J.

    1981-01-01

    Two files of nuclear structure data derived largely from the seventh edition of the Table of Isotopes are described. The files are computer oriented, and have been constructed to so that every decay can be traced either to an eventual ground state of to a positive flag that indicates nothing is known about further decay. The ENSL file contains level schemes derived from decay data, and the CDRL file contains the level schemes derived from particle-induced reaction data that have been merged into the ENSL file. (author)

  6. Extensions to COGEND for ENDF/B-V output of spontaneous fission decay data

    International Nuclear Information System (INIS)

    Tobias, A.

    1978-06-01

    The computer code COGEND, used to produce ENDF/B-IV or -V format nuclear decay scheme data, has been modified in order to extend its range of application. Details are given of the additional facilities which permit the handling of spontaneous fission decay data including any associated continuous spectra. In order to accommodate these additional features it is necessary to increase the core region by 4 kilobytes. (author)

  7. Gamma decay and nuclear reactions in a field of an intensive electromagnetic wave

    International Nuclear Information System (INIS)

    Dobrynin, Yu.L.; Zaretskij, D.F.; Lomonosov, V.V.

    1979-01-01

    The effect of a laser radiation field on the value of nuclear reaction cross sections is investigated. In the dipole nonrelativistic approximation considered is the interaction of an electromagnetic field with an ion, in the nucleus of which γ transition occurs from one energy level to another. The expression for the probability of γ transition in the laser field has been obtained. Resonance neutron scattering on the isolated level of a compound nucleus is considered. The conclusion has been done, that in strong electromagnetic fields the amplitudes of inelastic neutron scattering at the excited level of the compound nucleus obtain additional satellites, which are away the value, equal to +-ω (approximately 0.12 eV energy of CO 2 laser) from the main pole. It is shown, that in the field of a strong electromagnetic wave a nonrecoil emission of γ quanta is possible in laser plasma resulted from the stimulated emission (absorption) of quanta of an electromagnetic field by an ion. Considered is the effect of a strong electromagnetic wave on the value of the cross sections of inelastic neutron interaction with nucleus near the level of the compound nucleus. Laser parameters, which is necessary for the observation of the effects considered, are estimated

  8. Decay heat power of spent nuclear fuel of power reactors with high burnup at long-term storage

    Science.gov (United States)

    Ternovykh, Mikhail; Tikhomirov, Georgy; Saldikov, Ivan; Gerasimov, Alexander

    2017-09-01

    Decay heat power of actinides and fission products from spent nuclear fuel of power VVER-1000 type reactors at long-term storage is calculated. Two modes of storage are considered: mode in which single portion of actinides or fission products is loaded in storage facility, and mode in which actinides or fission products from spent fuel of one VVER reactor are added every year in storage facility during 30 years and then accumulated nuclides are stored without addition new nuclides. Two values of fuel burnup 40 and 70 MW·d/kg are considered for the mode of storage of single fuel unloading. For the mode of accumulation of spent fuel with subsequent storage, one value of burnup of 70 MW·d/kg is considered. Very long time of storage 105 years accepted in calculations allows to simulate final geological disposal of radioactive wastes. Heat power of fission products decreases quickly after 50-100 years of storage. The power of actinides decreases very slow. In passing from 40 to 70 MW·d/kg, power of actinides increases due to accumulation of higher fraction of 244Cm. These data are important in the back end of fuel cycle when improved cooling system of the storage facility will be required along with stronger radiation protection during storage, transportation and processing.

  9. Decay heat power of spent nuclear fuel of power reactors with high burnup at long-term storage

    Directory of Open Access Journals (Sweden)

    Ternovykh Mikhail

    2017-01-01

    Full Text Available Decay heat power of actinides and fission products from spent nuclear fuel of power VVER-1000 type reactors at long-term storage is calculated. Two modes of storage are considered: mode in which single portion of actinides or fission products is loaded in storage facility, and mode in which actinides or fission products from spent fuel of one VVER reactor are added every year in storage facility during 30 years and then accumulated nuclides are stored without addition new nuclides. Two values of fuel burnup 40 and 70 MW·d/kg are considered for the mode of storage of single fuel unloading. For the mode of accumulation of spent fuel with subsequent storage, one value of burnup of 70 MW·d/kg is considered. Very long time of storage 105 years accepted in calculations allows to simulate final geological disposal of radioactive wastes. Heat power of fission products decreases quickly after 50-100 years of storage. The power of actinides decreases very slow. In passing from 40 to 70 MW·d/kg, power of actinides increases due to accumulation of higher fraction of 244Cm. These data are important in the back end of fuel cycle when improved cooling system of the storage facility will be required along with stronger radiation protection during storage, transportation and processing.

  10. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    2012-10-06

    Oct 6, 2012 ... nuclear decay of neutrinoless double beta decay typically leading to sub-eV values as well. (Z, A) → (Z + 2, A) + 2e .... Here again energy resolution matters, because of the continuous spectrum of the 2νββ- decay mode, its high .... The benefit of using Te is its high natural abundance. This experiment is in ...

  11. Application of atomic mutations included in nuclear reactions, 40Ar(γ, p)39Cl(β decay)39Ar, to surface study

    International Nuclear Information System (INIS)

    Ohkuma, Juzo

    1987-01-01

    It has been found that the nuclear transformation processes which are initiated by photonuclear reactions can be used for studying the adsorption and chemical reactions taking place on solid surfaces. Chemically reactive 39 Cl was produced by irradiating 40 Ar with high-energy bremsstrahlung, and its blow was directed onto several material surfaces. The amount of chlorine adsorption was ascertained by detecting its radioactivity. Desorption without heating the adsorber samples inevitably occurred owing to the nuclear decay of 39 Cl. The adsorption and desorption rates were compared for several elements. A fast growth of oxide islands on sample surfaces was observed during the adsorption-desorption process. (author)

  12. Fuzzy optimization approach for the reliability of various schemes and fuzzy identification of weights in multicriteria optimization in control systems of nuclear reactors and power plants

    International Nuclear Information System (INIS)

    Zhuchkov, A.A.; Al'masri, Kh.F.

    2015-01-01

    An implementation of fuzzy optimization in the reliability of multicriteria selections in control schemes of nuclear reactors and power plants has been presented. In particular, optimization based on the theory of fuzzy sets has been proposed for the majority schemes, taking into account various reasons of failures. Set of fuzzy algorithms has been suggested as a basic technology for ranking process according to standard criterion, which includes steps of construction of the rules, initial estimation, fuzzification, and defuzzification. Software implementations have been presented for the fuzzy approach using the MatLab package [ru

  13. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    Abstract. The physics potential of neutrinoless double beta decay is discussed. Furthermore, experimental considerations as well as the current status of experiments are presented. Finally, an outlook towards the future, work on nuclear matrix elements and alternative processes is given.

  14. Nuclear deformation and searches of neutrinoless double-beta decay (0 νββ) : A case study of 76Ge

    Science.gov (United States)

    Janssens, Robert V. F.; Ayangeakaa, Akaa Daniel; ANL Collaboration; LLNL Collaboration; LLBL Collaboration; Maryland Collaboration

    2017-09-01

    Observation of neutrinoless double-beta decay (0 νββ) would both demonstrate the Majorana nature of the neutrino and provide experimental access to its absolute mass scale. Over the last decade, wavefunction contributions for leading (0 νββ) candidates have been probed in a campaign of experiments utilizing transfer reactions to determine nucleon occupancies in a consistent way. While these studies have provided a great deal of information for comparison with theory, especially on contributions to the nuclear wavefunctions from competing orbitals, they lack sensitivity to the collective degrees of freedom which have been shown to be relevant in describing these nuclei. In this talk, we present results of a high-precision Coulomb excitation measurement of 76Ge, performed at Argonne National Laboratory using GRETINA and CHICO2. The results are compared with state-of-the-art shell model calculations and recently obtained (n , n ` γ) data, with emphasis on demonstrating the importance of nuclear deformation in determining the nuclear decay matrix elements. This work is supported by the DOE, Office of Science, Office of Nuclear Physics under Contract Number DE-AC02-06CH11357, and Grant No. DE-FG02-94ER40834 and DE-FG02-08ER41556.

  15. Decay of 83Sr

    International Nuclear Information System (INIS)

    Yu Xiaohan; Shi Shuanghui; Gu Jiahui

    1997-01-01

    The decay of 83 Sr was reinvestigated using γ singles and γ-γ-t coincidence measurement. A new level scheme of Rb, which contains 41 excited levels and about 180 transitions, is constructed. 19 new levels were added to the old level scheme and 8 formerly adopted levels were denied. A new data set of branching ratio, log(ft) value and spin parity was obtained

  16. Decay Rate of the Nuclear Isomer Th 229 (3 /2+,7.8 eV ) in a Dielectric Sphere, Thin Film, and Metal Cavity

    Science.gov (United States)

    Tkalya, E. V.

    2018-03-01

    The main decay channels of the anomalous low-energy 3 /2+(7.8 ±0.5 eV ) isomeric level of the Th 229 nucleus, namely the γ emission and internal conversion, inside a dielectric sphere, dielectric thin film, and conducting spherical microcavity are investigated theoretically, taking into account the effect of media interfaces. It is shown that (1) the γ decay rate of the nuclear isomer inside a dielectric thin film and dielectric microsphere placed in a vacuum or in a metal cavity can decrease (increase) in dozen of times, (2) the γ activity of the distributed source as a function of time can be nonexponential, and (3) the metal cavity, whose size is of the order of the radiation wavelength, does not affect the probability of the internal conversion in Th 229 , because the virtual photon attenuates at much shorter distances and the reflected wave is very weak.

  17. Comparisons between a new point kernel-based scheme and the infinite plane source assumption method for radiation calculation of deposited airborne radionuclides from nuclear power plants.

    Science.gov (United States)

    Zhang, Xiaole; Efthimiou, George; Wang, Yan; Huang, Meng

    2018-04-01

    Radiation from the deposited radionuclides is indispensable information for environmental impact assessment of nuclear power plants and emergency management during nuclear accidents. Ground shine estimation is related to multiple physical processes, including atmospheric dispersion, deposition, soil and air radiation shielding. It still remains unclear that whether the normally adopted "infinite plane" source assumption for the ground shine calculation is accurate enough, especially for the area with highly heterogeneous deposition distribution near the release point. In this study, a new ground shine calculation scheme, which accounts for both the spatial deposition distribution and the properties of air and soil layers, is developed based on point kernel method. Two sets of "detector-centered" grids are proposed and optimized for both the deposition and radiation calculations to better simulate the results measured by the detectors, which will be beneficial for the applications such as source term estimation. The evaluation against the available data of Monte Carlo methods in the literature indicates that the errors of the new scheme are within 5% for the key radionuclides in nuclear accidents. The comparisons between the new scheme and "infinite plane" assumption indicate that the assumption is tenable (relative errors within 20%) for the area located 1 km away from the release source. Within 1 km range, the assumption mainly causes errors for wet deposition and the errors are independent of rain intensities. The results suggest that the new scheme should be adopted if the detectors are within 1 km from the source under the stable atmosphere (classes E and F), or the detectors are within 500 m under slightly unstable (class C) or neutral (class D) atmosphere. Otherwise, the infinite plane assumption is reasonable since the relative errors induced by this assumption are within 20%. The results here are only based on theoretical investigations. They should

  18. Teleportation via decay

    Indian Academy of Sciences (India)

    Abstract. We present a rare example of a decay mechanism playing a constructive role in quantum information processing. We show how the state of an atom trapped in a cavity can be teleported to a second atom trapped in a distant cavity by the joint detection of photon leakage from the cavities. The scheme, which is ...

  19. Teleportation via decay

    Indian Academy of Sciences (India)

    2015-11-27

    Nov 27, 2015 ... We present a rare example of a decay mechanism playing a constructive role in quantum information processing. We show how the state of an atom trapped in a cavity can be teleported to a second atom trapped in a distant cavity by the joint detection of photon leakage from the cavities. The scheme, which ...

  20. Summary Report of an IAEA Technical Meeting on Co-ordination of the International Network of Nuclear Structure and Decay Data Evaluators

    International Nuclear Information System (INIS)

    Abriola, D.; Dimitriou, P.; Ricard-McCutchan, E.; Tuli, J.K.

    2013-08-01

    Biennial meetings of the International Network of Nuclear Structure and Decay Data (NSDD) evaluators are held under the auspices of the IAEA. The Network consists of evaluation groups and data service centres in several countries. This Network has the objective of providing up-to-date nuclear structure and decay data for all known nuclides by evaluating all existing experimental data. Data resulting from this international evaluation collaboration are included in the Evaluated Nuclear Structure Data File (ENSDF) and published in the journals Nuclear Physics A and Nuclear Data Sheets (NDS). The results represent the recommended 'best values' for the various nuclear structure and decay data properties. These data and bibliographic details are also available through the World Wide Web, CD-ROM, wall charts of the nuclides, Nuclear Wallet Cards and other such media. The US efforts are coordinated by the Coordinating Committee of the US Nuclear Data Program. The ENSDF master database is maintained by the US National Nuclear Data Centre at Brookhaven National Laboratory, and these data are also available from other distribution centres including the IAEA Nuclear Data Section. Biennial meetings of the Network are sponsored by the IAEA Nuclear Data Section, and have the following objectives: (a) coordination of the work of all centres and groups participating in the compilation, evaluation and dissemination of NSDD; (b) maintenance of and improvements to the standards and rules governing NSDD evaluations; (c) review of the development and common use of computerized systems and databases maintained specifically for this activity. In those meetings detailed studies and discussions are undertaken over a five-day period. This document represents a summary of the Network meeting held at the Kuwait Foundation for the Advancement of Sciences (KFAS), Safat, Kuwait, from 27 to 31 January 2013. Thirty-six nuclear data specialists from seventeen countries attended this meeting to

  1. Muon capture reaction on 100Mo to study the nuclear response for double-β decay and neutrinos of astrophysics origin

    Science.gov (United States)

    Hashim, I. H.; Ejiri, H.; Shima, T.; Takahisa, K.; Sato, A.; Kuno, Y.; Ninomiya, K.; Kawamura, N.; Miyake, Y.

    2018-01-01

    Ordinary muon capture (OMC) on enriched 100Mo isotopes was studied for the first time to investigate neutrino nuclear responses for neutrinoless double-β decays and supernova neutrino nuclear interactions. Muon capture on 100Mo proceeds mainly as 100Mo(μ ,x n )Nb-x100 with x being the number of neutrons emitted from negative muon capture. The Nb isotope mass distribution was obtained by measuring delayed γ rays from radioactive Nb-x100. By using the neutron emission model after the muon capture, the neutrino response (the strength distribution) for OMC was derived. The OMC strength distribution shows a giant resonance (GR) at the peak energy around 11-14 MeV, suggesting the concentration of the OMC strength at the muon GR region.

  2. "Alpha decays" of Be-10(Lambda) and B-10(Lambda) hypernuclei: Phenomenological analysis and role of nuclear structure

    Czech Academy of Sciences Publication Activity Database

    Majling, Lubomír; Kuzmin, V. A.; Tetereva, T. V.

    2004-01-01

    Roč. 67, č. 10 (2004), s. 1804-1809 ISSN 1063-7788 R&D Projects: GA ČR GA202/02/0930 Institutional research plan: CEZ:AV0Z1048901 Keywords : nonmesonic weak decay * Lambda-hypernuclei * shell Subject RIV: BE - Theoretical Physics Impact factor: 0.781, year: 2004

  3. Elemental activation analysis with decay and prompt gamma ray techniques, using isotopic neutron sources and a nuclear research reactor. Part of a coordinated programme on nuclear-based techniques in geology and mineral prospecting

    International Nuclear Information System (INIS)

    El-Kady, A.A.

    1979-05-01

    This is to review the research activities carried out through the IAEA research Project 1697/RB ''Elemental activation analysis with decay and prompt gamma ray techniques, using isotopic neutron sources and the nuclear research reactor. The programme of work includes: a) Development of decay and prompt gamma ray activation techniques for mineral exploration. b) Development of epithermal NAA in addition to thermal NAA especially for gold ore. c) Development of non-destructive insitu elemental analysis with decay and prompt gamma ray techniques using isotopic neutron sources. A joint programme has been established with the Egyptian Geological Surrey and Mining Authority for using nuclear techniques in evaluating gold prospects of several ancient gold mines and investigating several tin-tantalum deposits, which were discovered over the last few years. Two sources of neutrons were used for irradiation, one of the dry channels of the two megawatts research reactor, ET-RR-1 for laboratory studies, and a Pu-Be neutron source in paraffin assembly for possible insitu work

  4. New Decay Studies of 66Ga

    Science.gov (United States)

    Kumar, Suresh; Ahmad, I.; Carpenter, M. P.; Chen, J.; Greene, J. P.; Kondev, F. G.; Zhu, S.

    2014-03-01

    High-energy γ rays with energies up to 5.0 MeV are emitted in the radioactive decay of 66Ga (T1/2 = 9.49 h). Thus, this radionuclide appears to be a suitable candidate for energy and efficiency calibrations of high-resolution, γ-ray spectrometers that are employed in studies of very neutron-rich nuclei which have large Qβ values. In addition, accurate emission probabilities of this isotope are of interest to medical imaging applications, owing to the existence of large β+ decay branches, which need to be characterized with better accuracy. Decay studies of 66Ga were initiated using the γ-ray spectroscopy technique. The source was produced by means of the 66Zn(p,n) reaction at a beam energy of 12 MeV. Singles and γ - γ coincidences measurements were carried out using a single Ge detector and Gammasphere, respectively. The previously known 66Ga decay scheme was extended and many new γ rays were placed in the daughter nuclide 66Zn. The work at ANL was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357. S. Kumar acknowledges support from the Indo-US Science and Technology Forum for the award of a Research Fellowship.

  5. Positron-neutrino correlations in 32Ar and 33Ar decays: Probes of scalar weak currents and nuclear isospin mixing

    International Nuclear Information System (INIS)

    Garcia, A.; Adelberger, E.G.; Ortiz, C.; Swanson, H.E.; Beck, M.; Tengblad, O.; Borge, M.J.G.; Martel, I.; Bichsel, H.

    2000-01-01

    The positron-neutrino correlation in the 0 +→ 0 + β-decay of 32 Ar was measured at ISOLDE by analyzing the effect of lepton recoil on the shape of the narrow proton group following the super-allowed decay. Our result is consistent with the standard model prediction;for vanishing Fierz interference we find a=0.9989±0.0052±0.0039. Our result leads to improved constraints on scalar weak interactions. The positron-neutrino correlation in 33 Ar decay was measured in the same experiment;for vanishing Fierz interference we find a=0.944±0.002±0.003. The 32 Ar and 33 Ar correlations, in combination with precision measurements of the half-lives, super-allowed branching ratios and beta endpoint energies, will determine the isospin impurities of the super-allowed transitions. These will provide useful tests of isospin-violation corrections used in deducing vertical bar V ud vertical bar which currently indicates non-unitarity of the KM matrix

  6. Radioactive Decay

    Science.gov (United States)

    Radioactive decay is the emission of energy in the form of ionizing radiation. Example decay chains illustrate how radioactive atoms can go through many transformations as they become stable and no longer radioactive.

  7. Weak decays

    International Nuclear Information System (INIS)

    Wojcicki, S.

    1978-11-01

    Lectures are given on weak decays from a phenomenological point of view, emphasizing new results and ideas and the relation of recent results to the new standard theoretical model. The general framework within which the weak decay is viewed and relevant fundamental questions, weak decays of noncharmed hadrons, decays of muons and the tau, and the decays of charmed particles are covered. Limitation is made to the discussion of those topics that either have received recent experimental attention or are relevant to the new physics. (JFP) 178 references

  8. An analytical method for estimating the 14N nuclear quadrupole resonance parameters of organic compounds with complex free induction decays for radiation effects studies

    International Nuclear Information System (INIS)

    Iselin, L.H.

    1992-01-01

    The use of 14 N nuclear quadrupole resonance (NQR) as a radiation dosimetry tool has only recently been explored. An analytical method for analyzing 14 N NQR complex free induction decays is presented with the background necessary to conduct pulsed NQR experiments. The 14 N NQR energy levels and possible transitions are derived in step-by-step detail. The components of a pulsed NQR spectrometer are discussed along with the experimental techniques for conducting radiation effects experiments using the spectrometer. Three data analysis techniques -- the power spectral density Fourier transform, state space singular value decomposition (HSVD), and nonlinear curve fitting (using the downhill simplex method of global optimization and the Levenberg-Marquart method) -- are explained. These three techniques are integrated into an analytical method which uses these numerical techniques in this order to determine the physical NQR parameters. Sample data sets of urea and guanidine sulfate data are used to demonstrate how these methods can be employed to analyze both simple and complex free induction decays. By determining baseline values for biologically significant organics, radiation effects on the NQR parameters can be studied to provide a link between current radiation dosimetry techniques and the biological effects of radiation

  9. Nuclear transparency and double beta decay of molybdenum 100. Annual progress report, February 1, 1994--January 31, 1995

    International Nuclear Information System (INIS)

    Nicholson, H.W.

    1994-07-01

    During the past year, work has been nearly completed on a Physical Review paper with final results of a search for neutrinoless double-β decay of molybdenum 100 with collaborators from LBL, the University of New Mexico, and the Idaho Engineering Laboratory. Major part of this work was to carry out an extensive statistical analysis of the data. During the spring of 1994, Sean Sutton spent the majority of this time at Orsay, France working on NEMO 3, a next generation double-β decay experiment involving molybdenum 100 and other isotopes. Nicholson and Sutton have designed and built a scintillating fiber hadoscope used in the May--July AGS high energy physics run at BNL in AGS experiment 850 to measure color transparency. Professor Nicholson has had primary responsibility for the design, construction, and installation of this hodoscope and for overseeing the construction and installation of two scintillating counter upstream hodoscopes. To date, the fiber hodoscope had handled total beam rates exceeding 20 MHz with beam rates as high as 10 MHz on a single fiber. Light intensification and readout electronics to be used in the CsI(Tl) calorimeter in the SLAC B factory has just begun this summer

  10. 37-Active rods fuel element for Atucha 1 nuclear power plant. Effects of this change in design over the neutronic behavior, decay power and radioactive inventory

    International Nuclear Information System (INIS)

    Villar, Javier E.

    1999-01-01

    The influence of the use of 37-rods fuel element on the behavior of the Atucha 1 nuclear power plant homogeneous core with slightly enriched fuel to 0.85 w % were studied through representative parameters such as average discharge burnup, channel powers, reactivity coefficients, kinetic parameters, radioactive inventory and decay power. In general, the values of mentioned parameters are similar to those corresponding to a core with the 36-rods fuel element actually in use, although it must be emphasized a decrease both in linear power and, in minor degree, in the efficiency of shut-off and control rods and a slight increase in the discharge burnup. The fuel management strategy developed for a core with 36-rods elements can be maintained. (author)

  11. Investigation of parity admixtures in nuclear states by measuring the β-γ directional correlation of the 203Hg → 203Tl decay

    International Nuclear Information System (INIS)

    Dydak, F.

    1972-01-01

    As a consequence of a weak nucleon-nucleon interaction parity admixtures in nuclear states give rise to a small forward-backward asymmetry of γ-quanta with respect to the direction of β-particle emission. A highly accurate arrangement using four β- and two γ-detectors has been developed to determine the odd Legendre term A cos(theta) in the β-γ directional correlation of the cascade decay 203 Hg→ 203 Tl as well as a control value which should be zero. The electronic equipment is a specially designed nanosecond system. The sources were prepared by means of a mass separator. Possible systematic distortions of the experimental data were carefully examined. A generalized least squares fit method symmetric in all variables was deduced for a correct data evaluation. The measurements yielded the coefficient A 1 = -(2,7+-0,7).10 -4 and the control value +(0,7+-0,8).10 -4 . (author)

  12. Review of log ft values in β decay

    International Nuclear Information System (INIS)

    Singh, B.; Rodriguez, J.L.; Wong, S.S.M.; Tuli, J.K.

    1998-01-01

    The log ft values for all β decay branches (β-, β+, ε) have been retrieved from the Evaluated Nuclear Structure Data File (ENSDF--August 1997 version) and reviewed. Only those cases where the β transition occurs between levels of firmly assigned Jπ values (consistent with strong rules for Jπ assignments as given in policies of Nuclear Data Sheets), have been considered in this review. Weak β branches (≤1%) in complex decay schemes have been omitted. Some new values from recent literature have also been added. Out of a total of about 20,000 β transitions reported in ENSDF, about 3,900 are presented in this review. A similar complete review was last done by 63G1ZZ where about 900 transitions were considered, which included weak transitions as well as those between levels of tentative jπ assignments. The ft values in β decay, spanning about 21 orders of magnitude, have been classified into allowed and forbidden categories according to the classification scheme of Konopinski (43Ko08). Centroid, width, minimum and maximum values for each category have been calculated here. Lower limits for first and second forbidden transitions in the present review have been compared to those given in the review by Raman and Gove (73Ra10) which contained about 160 selected log ft values

  13. Decay ring status / studies

    CERN Document Server

    Chance, A

    2008-01-01

    The aim of "beta-beams" is to produce highly energetic pure electron neutrino and anti-neutrino beams coming from β-decay of radioactive ions. In CERN baseline, after accelerating, the ions 6He2+ and 18Ne10+ are stored in a racetrack-shaped-decay ring until they are lost [1]. Consequently, the injection compensates the losses which occurred between two cycles. Two main loss sources were identified: the β decay and the injection scheme. After giving the optics, we will see how to protect the magnetic elements from the decay products. The injections scheme will be then detailed with its implications. We will see that the injection process makes a collimation section in energy necessary. Since the magnetic elements are not perfect, we will take into account the magnet misalignment and the multipole defects in the dipoles. We will talk then about the closed orbit distortion due to misalignment defects and about the long-term transverse stability with the dynamic aperture.

  14. Measurements of observables in the pion-nucleon system, nuclear a- dependence of heavy quark production and rare decays of D and B mesons. Progress report, 1 December, 1990--15 February, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Sadler, M.E.; Isenhower, L.D.

    1992-02-15

    This report discusses research on the following topics: pion-nucleon interactions; detector tomography facility; nuclear dependence of charm and beauty quark production and a study of two-prong decays of neutral D and B mesons; N* collaboration at CEBAF; and pilac experiments. (LSP)

  15. 238Pu - Comments on Evaluation of Decay Data

    International Nuclear Information System (INIS)

    Chechev, V. P.

    2013-01-01

    This evaluation was done originally in March 2003, corrected in June 2004, and then updated in June 2009 with a literature cut-off by the same date. Decay Scheme: The decay scheme is based on 2007Br04. Some expected weak gamma-ray transitions were not observed directly in 238 Pu α-decay but have been adopted from decay of 234 Pa and 234 Np

  16. Radioactive decay and nuclear structure studies: Progress report, covering the period October 1, 1985 through September 30, 1986

    International Nuclear Information System (INIS)

    Walters, W.B.

    1986-01-01

    The results of a series of studies of nuclear structure performed at the on-line mass separator facility TRISTAN located at the High-Flux Beam Reactor at Brookhaven National Laboratory are reported. New data and interpretations are reported for the structure of /sup 130,131,132/Sb, /sup 139,141,143/Cs, 145 Ba, /sup 139,141,143/La, and 145 Pr. 22 refs., 23 figs., 1 tab

  17. Column: Factors Affecting Data Decay

    Directory of Open Access Journals (Sweden)

    Kevin Fairbanks

    2012-06-01

    Full Text Available In nuclear physics, the phrase decay rate is used to denote the rate that atoms and other particles spontaneously decompose. Uranium-235 famously decays into a variety of daughter isotopes including Thorium and Neptunium, which themselves decay to others. Decay rates are widely observed and wildly different depending on many factors, both internal and external. U-235 has a half-life of 703,800,000 years, for example, while free neutrons have a half-life of 611 seconds and neutrons in an atomic nucleus are stable.We posit that data in computer systems also experiences some kind of statistical decay process and thus also has a discernible decay rate. Like atomic decay, data decay fluctuates wildly. But unlike atomic decay, data decay rates are the result of so many different interplaying processes that we currently do not understand them well enough to come up with quantifiable numbers. Nevertheless, we believe that it is useful to discuss some of the factors that impact the data decay rate, for these factors frequently determine whether useful data about a subject can be recovered by forensic investigation.(see PDF for full column

  18. Evaluation of the Safety Issue Concerning the Potential for Loss of Decay Heat Removal Function due to Crude Oil Spill in the Ultimate Heat Sink of Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Jong Chull; Roh, Kyung Wan; Yune, Young Gill; Kang, Dong Gu; Kim, Hho Jhung [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2008-05-15

    A barge crashed into a moored oil tanker at about 7:15 a.m., Dec. 12, 2007, dumping around 10,500 tons of crude oil into the sea in Korea. The incident took place about 15 kilometers northwest of Manripo beach in South Chungcheong where is Korea's west coast in the Yellow Sea. In a few days, the oil slicks spread to the northern and southern tips of the Taean Peninsula by strong winds and tides. As time went the spilled oil floating on the surface of sea water was volatilized to become tar-balls and lumps and drifted far away in the southern direction. 13 days after the incident, some of oil slicks and tar lumps were observed to flow in the service water intake at the Younggwang nuclear power plants (NPPs) operating 6 reactors, which are over 150 km away from the incident spot in the southeastern direction. According to the report by the Younggwang NPPs, a total weight 83 kg of tar lumps was removed for about 3 days. Oil spills in the sea can happen in any country or anytime due to human errors or mistakes, wars, terrors, intentional dumping of waste oils, and natural disasters like typhoon and tsunami. In fact, there have been 7 major oil spills over 10,000 tons that have occurred around the world since 1983. As such serious oil spill incidents may happen near the operating power plants using the sea water as ultimate heat sink. To ensure the safe operation of nuclear reactors it is required to evaluate the potential for loss of decay heat removal function of nuclear reactors due to the spilled oils flowing in the service water intake, from which the service water is pumped. Thus, Korea Institute of Nuclear Safety identified this problem as one of the important safety. When an incident of crude oil spill from an oil carrier occurs in the sea near the nuclear power plants, the spilled oil can be transported to the intake pit, where all service water pumps locate, by sea current and wind drift (induced) current. The essential service water pumps take the

  19. Study of numerical schemes for two-phase flow in porous media for any meshes: application to storage of nuclear waste

    International Nuclear Information System (INIS)

    Angelini, O.

    2010-01-01

    The two-phase flow in porous media is a complex phenomenon and which relate to many industrial problems. EDF works on the feasibility and the safety of a storage in deep geologic layer of nuclear waste. In this domain the simulation of the two-phase flow in porous media is particularly important in at least three domains: first of all during the phase of ventilation of the galleries of the storage which could de-saturate the rock and so modify its properties, but also during the phase of re-saturation of the materials and finally during the arrival of the water on the metal parts contained in the storage which will then involve phenomena of corrosion and a hydrogen release. In this context, EDF wishes to obtain robust numerical methods without restrictive condition on the mesh. This work is dedicated at first to the development of the finite volume scheme SUSHI (Scheme Using Stabilization and Hybrid Interfaces) in the code of mechanics of EDF, Code Aster in order to simulate the two-phase flow in porous media. This scheme was developed in 2D and in 3D. At the same time a new formulation which allows to simulate in a uniform way the flows in saturated and unsaturated porous media for miscible and immiscible problems is proposed. Various studies simulating difficulties related to the problems of the storage of nuclear waste in deep geological layers were study. We can quote the study of a bi-material which advances the capillary re-balancing of a material by an other one possessing properties and initial very heterogeneous conditions in saturation. We will also quote the study of the injection of hydrogen in an porous media initially saturated in pure water which is proposed by the benchmark 'two-phase Flow' proposed by the GNR MOMAS. This study had for objective to bring to light the good treatment of the appearance of a phase in a saturated porous media and thus the relevance of our new formulation to study with a way unified a problem of saturated flow and a

  20. Nuclear structure around Z=28 and N=40 investigated by the beta decay of Fe, Co and Ni isotopes.

    OpenAIRE

    Pauwels, Dieter

    2009-01-01

    Introduction Nuclei near the Z=28 closed shell gap and the N=40 closed subshell gap d raw considerable interest in current nuclear-structure investigations. A ccording to the shell model, a pronounced shell closure exists at Z=28. At N=40, a rather large energy gap exists between the p1/2 and g9/2 orbi tals, but less pronounced than the gap at Z=28. One speaks of a subshell closure at N=40. At the crossing of Z=28 and N=40 lies 68Ni, which exhibits features char acteristic for double-ma...

  1. Beta and muon decays

    Energy Technology Data Exchange (ETDEWEB)

    Galindo, A.; Pascual, P.

    1967-07-01

    These notes represent a series of lectures delivered by the authors in the Junta de Energia Nuclear, during the Spring term of 1965. They were devoted to graduate students interested in the Theory of Elementary Particles. Special emphasis was focussed into the computational problems. Chapter I is a review of basic principles (Dirac equation, transition probabilities, final state interactions.) which will be needed later. In Chapter II the four-fermion punctual Interaction is discussed, Chapter III is devoted to the study of beta-decay; the main emphasis is given to the deduction of the formulae corresponding to electron-antineutrino correlation, electron energy spectrum, lifetimes, asymmetry of electrons emitted from polarized nuclei, electron and neutrino polarization and time reversal invariance in beta decay. In Chapter IV we deal with the decay of polarized muons with radiative corrections. Chapter V is devoted to an introduction to C.V.C. theory. (Author)

  2. Constraining neutrinoless double beta decay

    International Nuclear Information System (INIS)

    Dorame, L.; Meloni, D.; Morisi, S.; Peinado, E.; Valle, J.W.F.

    2012-01-01

    A class of discrete flavor-symmetry-based models predicts constrained neutrino mass matrix schemes that lead to specific neutrino mass sum-rules (MSR). We show how these theories may constrain the absolute scale of neutrino mass, leading in most of the cases to a lower bound on the neutrinoless double beta decay effective amplitude.

  3. Gamow-Teller decay and nuclear deformation: implementing of a new total absorption spectrometer, study of isotopes N {approx_equal} Z krypton and strontium; Decroissance Gamow-Teller et deformation nucleaire: mise en oeuvre d'un nouveau spectrometre a absorption totale, etude d'isotopes N {approx_equal} Z de krypton et strontium

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, E

    2002-12-01

    Nuclei with A {approx} 70 along the N=Z line are known to be the scene of phenomena closely related to the nuclear deformation and are of particular interest since theoretical mean field calculations predict that a large part of the Gamow-Teller resonance might be located below the ground state of the mother nucleus and then be accessible through {beta}-decay studies. These results have shown the effect of the shape of the ground state on the intensity of the Gamow-Teller strength. Thus, the experimental determination, through {delta}-decay, of the Gamow-Teller strength distribution and the comparison to the theoretical predictions allow to pin down the quadrupolar deformation parameter of the ground state of the parent nucleus. In order to study the neutron deficient isotopes of krypton (A=72,73,74,75) and strontium (A=76,77,78) and to establish the {beta}-strength on the full energy range, a new total absorption spectrometer (TAgS) has been built in the frame of an international collaboration and installed at the (SOLDE/CERN mass separator. For the data analysis, the response function R of the spectrometer has been calculated by means of Monte-Carlo simulations, based on the GEANT4 code, and of a statistical description of the level scheme in the daughter nucleus. The {beta}-feeding distribution has been obtained from experimental spectra through a method based on Bayes theorem and then converted into Gamow-Teller strength. The results coming from the {sup 74}Kr decay analysis allow to describe the ground state of such a nucleus as the coexistence of an oblate shape and of a prolate shape. In the case of {sup 76}Sr, the experimental Gamow-Teller strength distribution strongly indicates a prolate deformation. (author)

  4. Colour schemes

    DEFF Research Database (Denmark)

    van Leeuwen, Theo

    2013-01-01

    This chapter presents a framework for analysing colour schemes based on a parametric approach that includes not only hue, value and saturation, but also purity, transparency, luminosity, luminescence, lustre, modulation and differentiation.......This chapter presents a framework for analysing colour schemes based on a parametric approach that includes not only hue, value and saturation, but also purity, transparency, luminosity, luminescence, lustre, modulation and differentiation....

  5. Radioactive decay data tables

    Energy Technology Data Exchange (ETDEWEB)

    Kocher, D.C.

    1981-01-01

    The estimation of radiation dose to man from either external or internal exposure to radionuclides requires a knowledge of the energies and intensities of the atomic and nuclear radiations emitted during the radioactive decay process. The availability of evaluated decay data for the large number of radionuclides of interest is thus of fundamental importance for radiation dosimetry. This handbook contains a compilation of decay data for approximately 500 radionuclides. These data constitute an evaluated data file constructed for use in the radiological assessment activities of the Technology Assessments Section of the Health and Safety Research Division at Oak Ridge National Laboratory. The radionuclides selected for this handbook include those occurring naturally in the environment, those of potential importance in routine or accidental releases from the nuclear fuel cycle, those of current interest in nuclear medicine and fusion reactor technology, and some of those of interest to Committee 2 of the International Commission on Radiological Protection for the estimation of annual limits on intake via inhalation and ingestion for occupationally exposed individuals.

  6. Beta decay and strength distributions

    International Nuclear Information System (INIS)

    Hardy, J.C.

    1980-01-01

    With the increasing accessibility of nuclei far from stability, experimenters find themselves faced more and more often with complex β-decay schemes: nuclei with over 5 MeV of β-decay energy, exhibiting hundreds and perhaps thousands of transitions. A detailed level-by-level exposition of such schemes - for example, by studying β-delayed γ-rays - is at best prohibitively time consuming, and at worst actually impossible with current techniques. Furthermore, even if reliable schemes are obtained experimentally, their confrontation with theory is severely limited by the absence of theories sufficiently complete to account for such complex spectra. At best, it is the details of the first few excited states and the general features of the rest that are useful for comparison. From both points of view, experimental and theoretical, there is strong motivation to find a broader perspective, emphasizing these general features without being overwhelmed by a proliferation of detail

  7. The development of a speech act coding scheme to characterize communication patterns under an off-normal situation in nuclear power plants

    International Nuclear Information System (INIS)

    Kim, Seung Hwan; Park, Jin Kyun

    2009-01-01

    Since communication is an important means to exchange information between individuals/teams or auxiliary means to share resources and information given in the team and group activity, effective communication is the prerequisite for construct powerful teamwork by a sharing mental model. Therefore, unless communication is performed efficiently, the quality of task and performance of team lower. Furthermore, since communication is highly related to situation awareness during team activities, inappropriate communication causes a lack of situation awareness and tension and stress are intensified and errors are increased. According to lesson learned from several accidents that have actually occurred in nuclear power plant (NPP), consequence of accident leads most critical results and is more dangerous than those of other industries. In order to improve operator's cope ability and operation ability through simulation training with various off-normal condition, the operation groups are trained regularly every 6 months in the training center of reference NPP. The objective of this study is to suggest modified speech act coding scheme and to elucidate the communication pattern characteristics of an operator's conversation during an abnormal situation in NPP

  8. A,B,C's of nuclear science

    International Nuclear Information System (INIS)

    Noto, V.A.; Norman, E.B.; Chan, Yuen-Dat; Dairiki, J.; Matis, H.S.; McMahan, M.A.; Otto, R.

    1995-01-01

    This introductory level presentation contains information on nuclear structure, radioactivity, alpha decay, beta decay, gamma decay, half-life, nuclear reactions, fusion, fission, cosmic rays, and radiation protection. Nine experiments with procedures and test questions are included

  9. Detailed nuclear structure studies far from stability

    International Nuclear Information System (INIS)

    Wood, J.L.; Schwarzenberg, J.; Zganjar, E.F.; Rupnik, D.

    1991-01-01

    State-of--the-art spectroscopy of nuclei far from stability has achieved an extraordinary level of sophistication and detail in the last ten years. In principle, if a state can be populated, it can be characterized by its energy, spin, parity, and major decay paths. Sometimes its lifetime can be measured. In practice, one is confronted with enormous complexity. To convert raw spectroscopic data into nuclear structure data involves a complex process of disentangling gamma rays and conversion electrons into decay schemes. Specifically, coincidence techniques, especially coincidence intensities, play a crucial role in this process. Recent examples and methods from work done at UNISOR are presented

  10. JENDL FP decay data file 2000

    Energy Technology Data Exchange (ETDEWEB)

    Katakura, Jun-ichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Yoshida, Tadashi [Musashi Inst. of Tech., Tokyo (Japan); Oyamatsu, Kazuhiro [Aichi Shukutoku Univ., Nagakute, Aichi (Japan); Tachibana, Takahiro [Waseda Univ., Tokyo (Japan)

    2001-07-01

    A decay data file of fission product (FP) nuclides has been developed for the use in nuclear technology field as one of special purpose files of JENDL (Japanese Evaluated Nuclear Data Library) in the format of ENDF/B and it is called JENDL FP Decay Data File 2000. The file includes the decay data for 1229 fission product nuclides: 142 stable and 1087 unstable nuclides. The data included for a nuclide are decay modes, their Q values and branching ratios, average decay energy values of beta-rays, gamma-rays and alpha-particles and their spectral data. The primary source of the decay data is ENSDF (Evaluated Nuclear Structure Data File), which is the internationally recognized data file of nuclear structure properties. The data in ENSDF, however, cover only measured ones. The data of the short-lived nuclides needed for the application fields such as decay heat prediction are often incomplete or not measured because of their short half-lives. For such nuclides a theoretical model calculation is applied to derive the needed data such as average decay energies and spectral data. The data in JENDL FP Decay Data File 2000 have been tested by summation calculation comparing its results with measured data of decay heat values and aggregate fission product spectra of various fissioning nuclei. The comparison showed good agreement between the calculated results and the measured values. (author)

  11. B decays

    CERN Document Server

    Stone, Sheldon

    1994-01-01

    This book reviews the study of b quarks and also looks at the implications of future studies. The most important observations thus far - including measurement of the ""B"" lifetime and observations of b -> u transitions - as well as the more mundane results of hadronic and semileptonic transitions are described in detail by experimentalists who have been closely involved with the measurements. Theoretical progress in understanding b quark decays, including the mechanisms of hadronic and semileptonic decays, are described. Synthesizing the experimental and theoretical information, the authors d

  12. B decays

    CERN Document Server

    Stone, Sheldon

    1992-01-01

    The study of b quarks has now reached a stage where it is useful to review what has been learned so far and also to look at the implications of future studies. The most important observations thus far - measurement of the "B" lifetime, B 0 - B 0 mixing, and the observation of b? u transitions, as well as more mundane results on hadronic and semileptonic transitions - are described in detail by experimentalists who have been closely involved with the measurements. Theoretical progress in understanding b quark decays, including the mechanisms of hadronic and semileptonic decays, are described. S

  13. Refinement of the gross theory of nuclear {beta}-decay, and hindrance of the first-forbidden transition of rank 1

    Energy Technology Data Exchange (ETDEWEB)

    Nakata, Hidehiko [Waseda Univ., Tokyo (Japan). Dept. of Physics; Tachibana, Takahiro; Yamada, Masami

    1997-03-01

    Recently the gross theory of nuclear {beta}-decay was refined for odd-odd nuclei. In this refinement, the effect of the selection rule of {beta}-transitions from the ground states of odd-odd nuclei to those of even-even nuclei was taken into account based on a statistical consideration. The transitions to the first 2{sup +} excited states in even-even nuclei were also taken into account according to the selection rule approximately. In that study, it was found that the transitions between 1{sup -} ground states of the odd-odd nuclei and 0{sup +} ground states of even-even nuclei, belonging to the first-forbidden transitions of rank 1, are strongly hindered. A reduction factor was introduced for the transitions to the ground states of even-even nuclei to take into account this hindrance. It was also found that the strength functions of the Gamow-Teller transitions obtained from the conventional gross theory are underestimated by a factor of about 3. In order to improve this underestimation, the Lorentz-type function was adopted for the one-particle strength function in the model instead of the hyperbolic-secant-type function. In the present study we have newly analyzed the experimental ft-values of odd-A nuclei, and found that the first-forbidden transitions of rank 1 are also considerably hindered between the ground states. Following the above refinement we have calculated the {beta}-ray spectra of some odd-odd short-lived fission products with the use of the refined gross theory. These results are compared not only with the experiments by Rudstam et al. but also with the conventional gross theory. (author)

  14. Search for $^{73}$Rb and Investigation of Nuclear Decay Modes Near the Z=N Line in the Border Region of the Astrophysical RP-Process Path

    CERN Multimedia

    2002-01-01

    % IS351 \\\\ \\\\ Following a test experiment on the production rates of $^{73}$Rb and $^{74}$Rb and the negative result concerning the existence of $^{73}$Rb, we have studied the mirror $\\beta$- decay of $^{71}$Kr and observed for the first time the $\\beta$- decay of $^{70}$Kr. The $\\beta$- decay study of $^{71}$Kr extends the systematics of mirror decays to an upper $fp$-shell. The observation of the $\\beta$- decay of $^{70}$Kr resulted in the first half-life measurement of this nucleus. Our result disagrees with the value used in the recent rp-process calculations. The new half-life value may increase the effective two proton capture rate of $^{68}$Se by a factor of 6.5.

  15. Tradable schemes

    NARCIS (Netherlands)

    J.K. Hoogland (Jiri); C.D.D. Neumann

    2000-01-01

    textabstractIn this article we present a new approach to the numerical valuation of derivative securities. The method is based on our previous work where we formulated the theory of pricing in terms of tradables. The basic idea is to fit a finite difference scheme to exact solutions of the pricing

  16. Communication dated 30 May 2007 from the Permanent Mission of the United Kingdom of Great Britain and Northern Ireland to the IAEA concerning enrichment bonds - A voluntary scheme for reliable access to nuclear fuel

    International Nuclear Information System (INIS)

    2007-01-01

    The Secretariat has received a letter dated 30 May 2007 from the Permanent Mission of the United Kingdom of Great Britain and Northern Ireland to the IAEA attaching a UK Non-paper entitled 'Food for Thought: Enrichment Bonds - A Voluntary Scheme for Reliable Access to Nuclear Fuel'. As requested in that letter, the letter and the attachment is now being circulated for the information of all Member States

  17. Simulation of decay processes and radiation transport times in radioactivity measurements

    Science.gov (United States)

    García-Toraño, E.; Peyres, V.; Bé, M.-M.; Dulieu, C.; Lépy, M.-C.; Salvat, F.

    2017-04-01

    The Fortran subroutine package PENNUC, which simulates random decay pathways of radioactive nuclides, is described. The decay scheme of the active nuclide is obtained from the NUCLEIDE database, whose web application has been complemented with the option of exporting nuclear decay data (possible nuclear transitions, branching ratios, type and energy of emitted particles) in a format that is readable by the simulation subroutines. In the case of beta emitters, the initial energy of the electron or positron is sampled from the theoretical Fermi spectrum. De-excitation of the atomic electron cloud following electron capture and internal conversion is described using transition probabilities from the LLNL Evaluated Atomic Data Library and empirical or calculated energies of released X rays and Auger electrons. The time evolution of radiation showers is determined by considering the lifetimes of nuclear and atomic levels, as well as radiation propagation times. Although PENNUC is designed to operate independently, here it is used in conjunction with the electron-photon transport code PENELOPE, and both together allow the simulation of experiments with radioactive sources in complex material structures consisting of homogeneous bodies limited by quadric surfaces. The reliability of these simulation tools is demonstrated through comparisons of simulated and measured energy spectra from radionuclides with complex multi-gamma spectra, nuclides with metastable levels in their decay pathways, nuclides with two daughters, and beta plus emitters.

  18. EC/β+ decay of 161Er

    International Nuclear Information System (INIS)

    Kalinnikov, V.G.; Ibraheem, Y.S.; Stegailov, V.I.

    2004-01-01

    Full text: The study of odd-proton nuclei in rare-earth region has been performed to get more information on the nuclear structure of these nuclei. In the framework of a program at the ISOL complex of YASNAPP-2 at JINR to study the decay of odd-nuclei, 161 Er has been investigated. The experiments have been focused on the 161 Ho level scheme populated in the EC/β + decay of 161 Er for which a few results have been previously reported [1,2]. Spectra of single γ-ray, γ-γ coincidence and internal conversion electrons were measured. There are appreciable disagreements between results of some γ-ray intensities obtained by us and in [2]. The greatest difference was for relative γ-ray intensity of the 11.28 keV, which has reported value I γ ∼ 10 (I γ 211 =1000) in [2], but this leads to an overpopulation of the 211 keV level by 14% of the decay [3]. The relative intensities of transitions with Eγ γ211 =1000). Inaccuracy of Iγ in [2] is probably due to a sudden change in the efficiency curve of their Ge(Li) detector in the low energy region while our HPGe detector feature a much smoother variation in the efficiency curve in this γ-ray energy region. Besides, the levels earlier introduced by us in [4], three new levels in 161 Ho were proposed from γ-γ coincidences at energies 693.2 keV, 859.6 keV, and 957.97 keV. Spins, parities and Nilsson quantum characteristics of some 161 Ho levels were established

  19. β-decay properties in the Cs decay chain

    Science.gov (United States)

    Benzoni, G.; Lică, R.; Borge, M. J. G.; Fraile, L. M.; IDS collaboration

    2018-02-01

    The study of the decay of neutron-rich Cs isotopes has two main objectives: on one side β decay is a perfect tool to access the low-spin structures in the daughter Ba nuclei, where the evolution of octupole deformed shapes can be followed, while, on the other hand, the study of the gross properties of these decays, in terms of decay rates and branching to delayed-neutron emission, are fundamental inputs for the modelling of the r-process in the Rare-Earth Elements peak. Results obtained at CERN-ISOLDE are discussed within this framework and compared to existing data and predictions from state-of-the-art nuclear models.

  20. Decay spectroscopy of $^{178}$Au

    CERN Document Server

    Whitmore, B

    In this thesis, the neutron-deficient nucleus $^{178}$Au is investigated through decay spectroscopy. Si and HPGe detectors were used to analyse the decay radiation of $^{178}$Au and its daughter nuclei. Previous studies have been unable to distinguish decay radiation from different isomeric states of this nucleus. This thesis represents the first time such isomeric discrimination has been achieved, and presents tentative spin assignments of both the ground state and an isomer. The neutron-deficient gold isotopes are an area of interest for the study of shape coexistence. This is the phenomenon exhibited by nuclei able to exist at a number of close lying energy minima, each reflecting a distinct type of deformation. It is hoped that studies such as this can help identify the evolution of nuclear deformation in this region of the nuclear chart.

  1. Status of decay data evaluations for 233U and 229Th

    International Nuclear Information System (INIS)

    Mukherjee, G.

    2009-01-01

    Details of the evaluation of 233 U were described, which is now almost complete following the review process. Many experimental measurements have been made for this radionuclide, which undergoes effectively 100% α decay to 229 Th, with very minor spontaneous fission and cluster branches. A consistent set of measurements for the total half-life allow a weighted mean with a reduced 2 of 0.39 to be calculated, whereas for the spontaneous fission branch only a lower limit has been consistently measured. A complex decay scheme has been produced containing fifty-three levels in the 229 Th daughter, with 267 γ rays and thirty-one α-particle transitions. An energy value of 7.6(5) eV has been determined for the very low-lying level in 229 Th following work published in 2007 (2007Be16). A good Q-value balance is obtained from the decay scheme that compares well with the recommended value of Audi et al. Work on the decay of 229 Th is in the early stages, with the literature survey complete and an initial set of nuclear levels formulated. Work will also be undertaken with F.G. Kondev on 209 Tl and 209 Pb in conjunction with his ENSDF mass chain evaluation for A = 209

  2. Primary retention following nuclear recoil in β-decay: Proposed synthesis of a metastable rare gas oxide ((38)ArO4) from ((38)ClO4(-)) and the evolution of chemical bonding over the nuclear transmutation reaction path.

    Science.gov (United States)

    Timm, Matthew J; Matta, Chérif F

    2014-12-01

    Argon tetroxide (ArO4) is the last member of the N=50 e(-) isoelectronic and isosteric series of ions: SiO4(4-), PO4(3-), SO4(2-), and ClO4(-). A high level computational study demonstrated that while ArO4 is kinetically stable it has a considerable positive enthalpy of formation (of ~298kcal/mol) (Lindh et al., 1999. J. Phys. Chem. A 103, pp. 8295-8302) confirming earlier predictions by Pyykkö (1990. Phys. Scr. 33, pp. 52-53). ArO4 can be expected to be difficult to synthesize by traditional chemistry due to its metastability and has not yet been synthesized at the time of writing. A computational investigation of the changes in the chemical bonding of chlorate (ClO4(-)) when the central chlorine atom undergoes a nuclear transmutation from the unstable artificial chlorine isotope (38)Cl to the stable rare argon isotope (38)Ar through β-decay, hence potentially leading to the formation of ArO4, is reported. A mathematical model is presented that allows for the prediction of yields following the recoil of a nucleus upon ejecting a β-electron. It is demonstrated that below a critical angle between the ejected β-electron and that of the accompanying antineutrino their respective linear momentums can cancel to such an extent as imparting a recoil to the daughter atom insufficient for breaking the Ar-O bond. As a result, a primary retention yield of ~1% of ArO4 is predicted following the nuclear disintegration. The study is conducted at the quadratic configuration interaction with single and double excitations [QCISD/6-311+G(3df)] level of theory followed by an analysis of the electron density by the quantum theory of atoms in molecules (QTAIM). Crossed potential energy surfaces (PES) were used to construct a PES from the metastable ArO4 ground singlet state to the Ar-O bond dissociation product ArO3+O((3)P) from which the predicted barrier to dissociation is ca. 22kcal/mol and the exothermic reaction energy is ca. 28kcal/mol [(U)MP2/6-311+G(d)]. Copyright © 2014

  3. An introduction to nuclear waste immobilisation

    International Nuclear Information System (INIS)

    Ojovan, M.I.; Lee, W.E.

    2005-08-01

    Safety and environmental impact is of uppermost concern when dealing with the movement and storage of nuclear waste. The 20 chapters in this book cover all important aspects of immobilisation, from nuclear decay, to regulations, to new technologies and methods. Significant focus is given to the analysis of the various matrices used in transport: cement, bitumen and glass, with the greatest attention being given to glass. The last chapter concentrates on the performance assessment of each matrix, and on new developments of ceramics and glass composite materials, thermochemical methods and in-situ metal matrix immobilisation. The book thoroughly covers all issues surrounding nuclear waste: from where to locate nuclear waste in the environment, through nuclear waste generation and sources, treatment schemes and technologies, immobilisation technologies and waste forms, disposal and long term behaviour. Particular attention is paid to internationally approved and worldwide-applied approaches and technologies

  4. Safety characteristics of decay heat removal systems

    International Nuclear Information System (INIS)

    Hofmann, F.

    1991-01-01

    Safety features of the decay heat removal systems including power sunply and final heat sink are described. A rather high reliability and an utmost degree of independence from energy supply are goals to be attained in the design of the European Fast Reactor (EFR) decay heat removal scheme. Natural circulation is an ambitious design goal for EFR. All the considerations are performed within the frame of risk minimization

  5. Novel efficient hybrid‐DEM collision integration scheme

    OpenAIRE

    Buist, Kay A.; Seelen, Luuk J.H.; Deen, Niels G.; Padding, Johan T.; Kuipers, Hans J.A.M.

    2017-01-01

    A hybrid collision integration scheme is introduced, benefiting from the efficient handling of binary collisions in the hard sphere scheme and the robust time scaling of the soft sphere scheme. In typical dynamic dense granular flow, simulated with the soft sphere scheme, the amount of collisions involving more than two particles are limited, and necessarily so because of loss of energy decay otherwise. Because most collisions are binary, these collisions can be handled within one time step w...

  6. The Nucleus 59Cu. Complex Structure, Shape Evolution, Exotic Decay Modes

    International Nuclear Information System (INIS)

    Andreoiu, Corina

    2002-08-01

    High-spin states in the mass A∼60 region were populated using the state-of-art γ-ray spectrometers Gammasphere, Euroball, and GASP in conjunction with dedicated ancillary detectors. In particular, the 59 Cu nucleus was studied in several experiments, and a very extensive level scheme was determined. It comprises more than 320 transitions connecting about 150 excited states. Relative to mass, it is the most extensive level scheme known to date. Next to the spherical states at low excitation energy eight regular sequences of high-energy γ-ray transitions have been observed. They form rotational bands with various degree of deformation, which are interpreted in the light of the shell model and the configuration-dependent Cranked Nilsson-Strutinsky approach. One of the experiments was dedicated to the study of prompt particle decays. It revealed five prompt proton decays connecting five deformed states in three of the rotational bands in 59 Cu with three spherical states in the daughter nucleus 58 Ni. It is the first observation of the fine structure of the newly discovered prompt proton decay mode. The proton decays compete with the γ decay-out from the second minimum of the nuclear potential into the low-spin spherical states in the first minimum of the potential. The discrete γ decay-out mechanism of the yrast superdeformed band is investigated in detail. The nucleus 59 Zn, the mirror partner of 59 Cu, was identified for the first time, and the mirror symmetry of the T=1/2 A=59 pair is discussed

  7. Nuclear physics

    International Nuclear Information System (INIS)

    Kamal, Anwar

    2014-01-01

    Explains the concepts in detail and in depth. Provides step-by-step derivations. Contains numerous tables and diagrams. Supports learning and teaching with numerous worked examples, questions and problems with answers. Sketches also the historical development of the subject. This textbook explains the experimental basics, effects and theory of nuclear physics. It supports learning and teaching with numerous worked examples, questions and problems with answers. Numerous tables and diagrams help to better understand the explanations. A better feeling to the subject of the book is given with sketches about the historical development of nuclear physics. The main topics of this book include the phenomena associated with passage of charged particles and radiation through matter which are related to nuclear resonance fluorescence and the Moessbauer effect., Gamov's theory of alpha decay, Fermi theory of beta decay, electron capture and gamma decay. The discussion of general properties of nuclei covers nuclear sizes and nuclear force, nuclear spin, magnetic dipole moment and electric quadrupole moment. Nuclear instability against various modes of decay and Yukawa theory are explained. Nuclear models such as Fermi Gas Model, Shell Model, Liquid Drop Model, Collective Model and Optical Model are outlined to explain various experimental facts related to nuclear structure. Heavy ion reactions, including nuclear fusion, are explained. Nuclear fission and fusion power production is treated elaborately.

  8. Decay heat uncertainty quantification of MYRRHA

    Science.gov (United States)

    Fiorito, Luca; Buss, Oliver; Hoefer, Axel; Stankovskiy, Alexey; Eynde, Gert Van den

    2017-09-01

    MYRRHA is a lead-bismuth cooled MOX-fueled accelerator driven system (ADS) currently in the design phase at SCK·CEN in Belgium. The correct evaluation of the decay heat and of its uncertainty level is very important for the safety demonstration of the reactor. In the first part of this work we assessed the decay heat released by the MYRRHA core using the ALEPH-2 burnup code. The second part of the study focused on the nuclear data uncertainty and covariance propagation to the MYRRHA decay heat. Radioactive decay data, independent fission yield and cross section uncertainties/covariances were propagated using two nuclear data sampling codes, namely NUDUNA and SANDY. According to the results, 238U cross sections and fission yield data are the largest contributors to the MYRRHA decay heat uncertainty. The calculated uncertainty values are deemed acceptable from the safety point of view as they are well within the available regulatory limits.

  9. Decay heat uncertainty quantification of MYRRHA

    Directory of Open Access Journals (Sweden)

    Fiorito Luca

    2017-01-01

    Full Text Available MYRRHA is a lead-bismuth cooled MOX-fueled accelerator driven system (ADS currently in the design phase at SCK·CEN in Belgium. The correct evaluation of the decay heat and of its uncertainty level is very important for the safety demonstration of the reactor. In the first part of this work we assessed the decay heat released by the MYRRHA core using the ALEPH-2 burnup code. The second part of the study focused on the nuclear data uncertainty and covariance propagation to the MYRRHA decay heat. Radioactive decay data, independent fission yield and cross section uncertainties/covariances were propagated using two nuclear data sampling codes, namely NUDUNA and SANDY. According to the results, 238U cross sections and fission yield data are the largest contributors to the MYRRHA decay heat uncertainty. The calculated uncertainty values are deemed acceptable from the safety point of view as they are well within the available regulatory limits.

  10. Nuclear data online at the NNDC. Revision

    International Nuclear Information System (INIS)

    McLane, V.

    1998-01-01

    The National Nuclear Data Center provides information on nuclear reactions, nuclear structure, and decay data, and is a part of the Nuclear Data Center Network, established to coordinate the compilation and dissemination of nuclear data on an international scale

  11. Scheme Program Documentation Tools

    DEFF Research Database (Denmark)

    Nørmark, Kurt

    2004-01-01

    This paper describes and discusses two different Scheme documentation tools. The first is SchemeDoc, which is intended for documentation of the interfaces of Scheme libraries (APIs). The second is the Scheme Elucidator, which is for internal documentation of Scheme programs. Although the tools...... as named functions in Scheme. Finally, the Scheme Elucidator is able to integrate SchemeDoc resources as part of an internal documentation resource....

  12. Biological protection against nuclear radiation

    International Nuclear Information System (INIS)

    Mateescu, Silvia; Stanciu, Marcela

    2001-01-01

    the non-homogeneities in biological shields at nuclear reactors and several methods for calculating non-homogeneous shields are presented. Chapter 10 describes the principal materials used as biological shielding against nuclear radiations, such as steel, lead, light water, concrete, etc. as well as, their behaviour in radiation fields. In the chapter 11 several examples of evaluating the dose rates and designing biological shieldings are given. Finally, chapter 12 gives definition of nuclear safety, events and nuclear accidents. Here also aspects of the Chernobyl accident are presented. Six appendices are added containing data of general use such as level and decay schemes, attenuation coefficients, data referring to U-235 fission products, etc. The work represents a compact and coherent synthesis of the main shielding calculation methods offering at the same time the necessary numerical data. An up-date comprehensive reference list completes this monograph

  13. Additive operator-difference schemes splitting schemes

    CERN Document Server

    Vabishchevich, Petr N

    2013-01-01

    Applied mathematical modeling isconcerned with solving unsteady problems. This bookshows how toconstruct additive difference schemes to solve approximately unsteady multi-dimensional problems for PDEs. Two classes of schemes are highlighted: methods of splitting with respect to spatial variables (alternating direction methods) and schemes of splitting into physical processes. Also regionally additive schemes (domain decomposition methods)and unconditionally stable additive schemes of multi-component splitting are considered for evolutionary equations of first and second order as well as for sy

  14. Nuclear Decay Data for the International Reactor Dosimetry Library for Fission and Fusion (IRDFF: Updated Evaluations of the Half-Lives and Gamma Ray Intensities

    Directory of Open Access Journals (Sweden)

    Chechev Valery P.

    2016-01-01

    Full Text Available Updated evaluations of the half-lives and prominent gamma ray intensities have been presented for 20 radionuclides – dosimetry reaction residuals. The new values of these decay characteristics recommended for the IRDFF library were obtained using the approaches and methodology adopted by the working group of the Decay Data Evaluation Project (DDEP cooperation. The experimental data published up to 2014 were taken into account in updated evaluations. The list of radionuclides includes 3H, 18F, 22Na, 24Na, 46Sc, 51Cr, 54Mn, 59Fe, 57Co, 60Co, 57Ni, 64Cu, 88Y, 132Te, 131I, 140Ba, 140La, 141Ce, 182Ta, 198Au.

  15. $\\beta$-decay study of neutron-rich Tl and Pb isotopes

    CERN Multimedia

    It is proposed to study the structure of neutron-rich nuclei beyond $^{208}$Pb. The one-proton hole $^{211-215}$Tl and the semi magic $^{213}$Pb will be produced and studied via nuclear and atomic spectroscopy searching for long-lived isomers and investigating the $\\beta$-delayed $\\gamma$- emission to build level schemes. Information on the single particle structure in $^{211-215}$Pb, especially the position of the g$_{9/2}$ and i$_{11/2}$ neutron orbitals, will be extracted along with lifetimes. The $\\beta$-decay will be complemented with the higher spin selectivity that can be obtained by resonant laser ionization to single-out the decay properties of long-living isomers in $^{211,213}$Tl and $^{213}$Pb.

  16. Measurements of hyperon semileptonic decays at the CERN Super Proton Synchrotron

    International Nuclear Information System (INIS)

    Bourquin, M.; Chatelus, Y.; Brown, R.M.

    1983-06-01

    Results on five different hyperon semileptonic decays from the WA2 experiment, performed in the CERN SPS charged hyperon beam, have been analysed within the framework of the Cabibbo model. For the first time, the inconsistencies, which inevitably occur when the results from different experiments are combined, have been avoided in these comprehensive fits to high statistics data from a single hyperon decay experiment. Excellent agreement with the basic Cabibbo model has been obtained using the WA2 data either alone or together with neutron lifetime measurements. These results contrast strongly with other recent Cabibbo analyses which have indicated the presence of SU(3) breaking effects. Using additional information on ft values for superallowed nuclear Fermi transitions, an upper limit on the mixing parameter sintheta 3 in the Kobayashi-Maskawa six quark scheme has been obtained. (author)

  17. Superallowed 0+→0+ nuclear β decays: A critical survey with tests of the conserved vector current hypothesis and the standard model

    International Nuclear Information System (INIS)

    Hardy, J.C.; Towner, I.S.

    2005-01-01

    A complete and critical survey is presented of all half-life, decay-energy, and branching-ratio measurements related to 20 superallowed 0 + →0 + decays; no measurements are ignored, although some are rejected for cause and others updated. A new calculation of the statistical rate function f is described and experimental ft values determined. The associated theoretical corrections needed to convert these results into 'corrected' Ft values are discussed, and careful attention is paid to the origin and magnitude of their uncertainties. As an exacting confirmation of the conserved vector current hypothesis, the corrected Ft values are seen to be constant to three parts in 10 4 . These data are also used to set a new limit on any possible scalar interaction (assuming maximum parity violation) of C S /C V =-(0.00005±0.00130). The average Ft value obtained from the survey, when combined with the muon lifetime, yields the up-down quark-mixing element of the Cabibbo-Kobayashi-Maskawa (CKM) matrix, V ud =0.9738±0.0004, and the unitarity test on the top row of the matrix becomes vertical bar V ud vertical bar 2 + vertical bar V us vertical bar 2 + vertical bar V ub vertical bar 2 =0.9966±0.0014 using the Particle Data Group's currently recommended values for V us and V ub . If V us comes instead from two recent results on K e3 decay, the unitarity sum becomes 0.9996(11). Either result can be expressed in terms of the possible existence of right-hand currents. Finally, we discuss the priorities for future theoretical and experimental work with the goal of making the CKM unitarity test more definitive

  18. Study of the decay of hot nuclear systems formed in Au-induced reactions at E/A=60 MeV

    International Nuclear Information System (INIS)

    Delis, D.N.; Colonna, N.; Sui, Q.; Tso, K.

    1993-01-01

    Multifragment production was measured for the 197 Au + 12 C, 27 Al, 51 V, 63 Cu and 197 Au reactions at E/A= 60 MeV. Comparison of experimental observables to calculations with a dynamical code coupled to a statistical model indicates agreement with some features of the experimental data. Furthermore the logarithms of the branching ratios for binary, ternary, quaternary, and quinary decays plotted as a function of E -1/2 show a linear dependence that ,strongly suggests a statistical competition between the various multifraigment channels. Finally, by utilizing the momentum tensor, the shape of the most central events in momentum space has been determined

  19. Recent nuclear data work in China

    International Nuclear Information System (INIS)

    Ge Zhigang

    2015-01-01

    A brief of introduction about China nuclear activities will be introduced in this presentation, which including the view of nuclear data measurement, evaluation activity system of China and the progress of the nuclear data measurements and evaluations during recently years. As the main output of China Nuclear Data Center, The scheme of the new Chinese Evaluated Nuclear Data Library (CENDL) will be introduced also in this article. The new version of CENDL is general purpose evaluated nuclear data file which consists of the neutron reaction sub-library, the activation sub-library, decay data sub-library and fission yield sub-library. CENDL-3.2 can be used for the nuclear engineering, nuclear medicine and nuclear science etc. fields. The CENDL-3.2 is based on the previous version of CENDL and other special purpose libraries established by CNDC, the updated experimental information and new nuclear data evaluation methodologies. The progress of the evaluation methodologies during recently years in China will be introduced in this presentation. (author)

  20. beta decay of (78)Sr

    OpenAIRE

    Pérez-Cerdán, Ana Belén; Rubio, Berta; Gelletly, W.; Algora, Alejandro; Agramunt, Jorge; Burkard, K.; Huller W.; Nácher, Enrique; Sarriguren, Pedro; Caballero Ontanaya, Luis; Molina Palacios, Francisco Gabriel; Fraile, Luis M.; Reillo, E.; García Borge, María José; Dessagne, Ph.

    2011-01-01

    The gamma rays and conversion electrons emitted in the beta decay of (78)Sr to levels in (78)Rb have been studied using Ge detectors and a mini-orange spectrometer. A reliable level scheme based on the results of these experiments has been established. The properties of the levels in (78)Rb have been compared with calculations based on deformed Hartree-Fock with Skyrme interactions and pairing correlations in the BCS approximation. This has allowed an interpretation of the nature of the obser...

  1. Baryonic B decays

    Energy Technology Data Exchange (ETDEWEB)

    Kichimi, H. [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan). Institute of Particle and Nuclear Studies

    2005-07-01

    We present recent results of Baryonic B decays from Belle, which contain charmed and charmless baryonic decays into two to four body final states. We report the branching fractions, including new observations of the baryonic decays into two charmed baryons in the final states, and the charmless baryonic decay proceeding through b {yields} s{gamma} transition, and the low di-baryon mass enhancement structures observed in the three-body decays, based on 357 fb{sup -1} data. (author)

  2. Search for X-Ray Induced Acceleration of the Decay of the 31-yr Isomer 178Hf Using Synchrotron Radiation

    CERN Document Server

    Ahmad, I; Becker, J A; Gemmell, D S; Krämer, A; Mashayekhi, A; McNabb, D P; Miller, G G; Moore, E F; Pangault, L N; Rundberg, R S; Schiffer, J P; Shastri, S D; Wang, T F; Wilhelmy, J B

    2002-01-01

    Releasing the energy stored in an isomeric nuclear state in a controlled way with an atomic or electromagnetic trigger is an attractive speculation: the energy gain may be on the order of the ratio of nuclear/atomic energies - MeV/keV. (Nuclear isomers are loosely defined as excited nuclear states with lifetimes longer than 10 sup - sup 9 s.) Nuclear isomers, therefore, represent an opportunity for a stand-alone energy source if suitable schemes for trigger and control of the energy release can be found. Potential applications include space drive, as well as very bright gamma-ray sources. The nucleus sup 1 sup 7 sup 8 Hf has a nuclear isomer with excitation energy E sub x = 2.447 MeV. The 2.447-MeV isomeric state decays slowly (t sub 1 sub / sub 2 = 31 y) to the nearby state at 2.433 MeV. The J suppi = 13 sup - state loses energy in a rapid (t approx 10 sup - sup 1 sup 2 s) gamma-ray cascade ending at the 8 sup - rotational band head which in turn decays via the ground-state rotational band cascade. The gamma...

  3. In-trap decay spectroscopy for {beta}{beta} decays

    Energy Technology Data Exchange (ETDEWEB)

    Brunner, Thomas

    2011-01-18

    The presented work describes the implementation of a new technique to measure electron-capture (EC) branching ratios (BRs) of intermediate nuclei in {beta}{beta} decays. This technique has been developed at TRIUMF in Vancouver, Canada. It facilitates one of TRIUMF's Ion Traps for Atomic and Nuclear science (TITAN), the Electron Beam Ion Trap (EBIT) that is used as a spectroscopy Penning trap. Radioactive ions, produced at the radioactive isotope facility ISAC, are injected and stored in the spectroscopy Penning trap while their decays are observed. A key feature of this technique is the use of a strong magnetic field, required for trapping. It radially confines electrons from {beta} decays along the trap axis while X-rays, following an EC, are emitted isotropically. This provides spatial separation of X-ray and {beta} detection with almost no {beta}-induced background at the X-ray detector, allowing weak EC branches to be measured. Furthermore, the combination of several traps allows one to isobarically clean the sample prior to the in-trap decay spectroscopy measurement. This technique has been developed to measure ECBRs of transition nuclei in {beta}{beta} decays. Detailed knowledge of these electron capture branches is crucial for a better understanding of the underlying nuclear physics in {beta}{beta} decays. These branches are typically of the order of 10{sup -5} and therefore difficult to measure. Conventional measurements suffer from isobaric contamination and a dominating {beta} background at theX-ray detector. Additionally, X-rays are attenuated by the material where the radioactive sample is implanted. To overcome these limitations, the technique of in-trap decay spectroscopy has been developed. In this work, the EBIT was connected to the TITAN beam line and has been commissioned. Using the developed beam diagnostics, ions were injected into the Penning trap and systematic studies on injection and storage optimization were performed. Furthermore, Ge

  4. Progress on Chinese evaluated nuclear parameters library (CENPL). Pt. 3

    International Nuclear Information System (INIS)

    Su Zongdi; Ge Zhigang; Zhou Chunmei

    1994-01-01

    The progress on Chinese evaluated nuclear parameters library (CENPL) is introduced. The setting up work of each sub-library of CENPL has got some new progresses at the past period. These sub-libraries are atomic mass and characteristic constant for nuclear ground state sub-library, discrete level scheme and batch ratio of γ decay sub-library, level density parameter sub-library, giant dipole resonance parameter for γ-ray strength function sub-library and optical model parameter sub-library

  5. [Estimation of cost-saving for reducing radioactive waste from nuclear medicine facilities by implementing decay in storage (DIS) in Japan].

    Science.gov (United States)

    Kida, Tetsuo; Hiraki, Hitoshi; Yamaguchi, Ichirou; Fujibuchi, Toshioh; Watanabe, Hiroshi

    2012-01-01

    DIS has not yet been implemented in Japan as of 2011. Therefore, even if risk was negligible, medical institutions have to entrust radioactive temporal waste disposal to Japan Radio Isotopes Association (JRIA) in the current situation. To decide whether DIS should be implemented in Japan or not, cost-saving effect of DIS was estimated by comparing the cost that nuclear medical facilities pay. By implementing DIS, the total annual cost for all nuclear medical facilities in Japan is estimated to be decreased to 30 million yen or less from 710 million yen. DIS would save 680 million yen (96%) per year.

  6. The decay of /sup 185/Hg low-spin states in /sup 185/Au as a probe of the nuclear models

    CERN Document Server

    Bourgeois, C; Kilcher, P; Roussière, B; Sauvage-Letessier, J

    1981-01-01

    The /sup 185/Au has been studied from the beta /sup +//EC decay of /sup 185m+g/Hg using the ISOCELE facility. Conversion electron measurements have been performed by means of a semi-circular magnetic spectrograph: new low-energy transitions have been observed. A 330 keV very converted transition has also been found. Its existence is discussed. In addition to the usual states observed in heavier gold isotopes, numerous negative-parity low-spin states have been located. The experimental states corresponding to a prolate shaped nucleus are compared with those extracted from an 'axial rotor+quasi-particle' coupling model. They could be identified with two state families, the first one arising from the h9/2+f5/2 sub-shells, the second from the p3/2+f7/2 sub-shells. (12 refs).

  7. Study of the decay of hot nuclear systems formed in Au-induced reactions at E/A=60 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Delis, D.N.; Colonna, N.; Sui, Q.; Tso, K. [Lawrence Berkeley Laboratory, CA (United States)] [and others

    1993-10-01

    Multifragment production was measured for the {sup 197}Au +{sup 12}C, {sup 27}Al, {sup 51}V, {sup 63}Cu and {sup 197}Au reactions at E/A= 60 MeV. Comparison of experimental observables to calculations with a dynamical code coupled to a statistical model indicates agreement with some features of the experimental data. Furthermore the logarithms of the branching ratios for binary, ternary, quaternary, and quinary decays plotted as a function of E{sup -{1/2}} show a linear dependence that ,strongly suggests a statistical competition between the various multifraigment channels. Finally, by utilizing the momentum tensor, the shape of the most central events in momentum space has been determined.

  8. Study of the Production Mechanisms and Decay Properties of Charmed Particles Observed in Nuclear Emulsions Coupled to the NA14 Spectrometer

    CERN Multimedia

    2002-01-01

    The aims of this test experiment are: \\item a)~~~~to check the expected improvement in scanning speed and efficiency, due to the use of the microstrip vertex detector of the NA14 set-up and to the help of automated microscopes; \\item b)~~~~to evaluate the enrichment factor in the charmed event content of the sample to be searched, due to the particle identification power and the vertex detector of NA14; \\item c)~~~~to collect some 100 pairs of charmed particles, produced and decaying in emulsion, which would allow a comparison with the results from the WA58 experiment, in particular about the possible energy dependence of the production mechanism of associated @L^c|+~$\\bar{D}$. \\end{enumerate} The incident beam will consist of tagged photons between 70 and 150-200~GeV.

  9. Levels of 250Cf populated in the decay of 250Bk

    International Nuclear Information System (INIS)

    Uecke, J.W.

    1975-06-01

    The nuclide 250 Bk undergoes β-decay with a half-life of 3.2 h to 13.1 y 250 Cf. A study is undertaken of the excited states in 250 Cf populated by 250 Bk decay which results from the α-decay of 276d 254 Es. The general features of published level schemes for these nuclei are consistent with predictions of the Nilsson and collective models; however, there remain many undiscovered transitions and ambiguous or uncertain level assignments. In an attempt to confirm predictions of current theoretical models which account for nuclear level assignments in this nucleus, these gamma transitions and their levels have been studied. Twenty-eight new γ-rays were determined. The decay of 250 Bk is investigated primarily by high resolution gamma-ray singles spectrometry and supported in part by two-parameter gamma-gamma coincidence spectrometry. The equipment, comprised of a Ge(HP) and a large volume Ge(Li) detector, a 4096-channel two-parameter analyzer, and a PDP-8/e computer system, permitted significant improvement in sensitivity and accuracy over previous investigations on this nucleus. (11 figures, 2 tables) (U.S.)

  10. Nuclear Data Sheets for A=164

    Science.gov (United States)

    Singh, Balraj; Chen, Jun

    2018-01-01

    Experimental nuclear structure data for the known A=164 isobaric nuclides (Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir) have been evaluated, and presented together with Adopted properties of level energies, and associated γ rays. The decay data for these nuclides have also been evaluated, providing Adopted values of γ and β radiations, and log ft values. No excited states are known in 164Eu, 164Tb, and 164Ir. Information for 164Gd, 164Re and 164Os is limited due to insufficient experimental data. For radioactive nuclides, decay schemes of 164Sm, 164Gd and 164Re are not known, and those of 164W, 164Tb, 164Lu, 164Hf, 164Ta and 164W are incomplete. The decay schemes of 164Ho and the two activities of 164Tm seem fairly complete. The decay scheme of 164Yb presents a major problem that the Q(ε) value of 887 keV 29 recommended in 2017Wa10 is in disagreement with the population of levels at 928, 952 and 1060 keV in the daughter nucleus. This decay scheme, which so far has been mainly reported in a secondary reference (1982AdZZ) needs further investigation. Also the masses of 164Yb and 164Tm need either new measurements or a re-evaluation to resolve discrepancy of about 220 keV in the Q value of 164Yb decay to 164Tm. The reactions and decays for which no new experimental information has become available since the 2001 update have undergone revisions to incorporate conversion coefficients from BrIcc code, and evaluated Q values from 2017Wa10, but the essential content of such datasets may have remained the same as in previous evaluations. In this respect the present work greatly benefited from all the previous NDS evaluations (2001Si27,1992Sh07, 1986Sh03,1974Bu30), but at the same time data presented herein supersede all the previous published evaluations.

  11. Decay heat uncertainty quantification of MYRRHA

    OpenAIRE

    Fiorito Luca; Buss Oliver; Hoefer Axel; Stankovskiy Alexey; Eynde Gert Van den

    2017-01-01

    MYRRHA is a lead-bismuth cooled MOX-fueled accelerator driven system (ADS) currently in the design phase at SCK·CEN in Belgium. The correct evaluation of the decay heat and of its uncertainty level is very important for the safety demonstration of the reactor. In the first part of this work we assessed the decay heat released by the MYRRHA core using the ALEPH-2 burnup code. The second part of the study focused on the nuclear data uncertainty and covariance propagation to the MYRRHA decay hea...

  12. Numerical schemes for explosion hazards

    International Nuclear Information System (INIS)

    Therme, Nicolas

    2015-01-01

    In nuclear facilities, internal or external explosions can cause confinement breaches and radioactive materials release in the environment. Hence, modeling such phenomena is crucial for safety matters. Blast waves resulting from explosions are modeled by the system of Euler equations for compressible flows, whereas Navier-Stokes equations with reactive source terms and level set techniques are used to simulate the propagation of flame front during the deflagration phase. The purpose of this thesis is to contribute to the creation of efficient numerical schemes to solve these complex models. The work presented here focuses on two major aspects: first, the development of consistent schemes for the Euler equations, then the buildup of reliable schemes for the front propagation. In both cases, explicit in time schemes are used, but we also introduce a pressure correction scheme for the Euler equations. Staggered discretization is used in space. It is based on the internal energy formulation of the Euler system, which insures its positivity and avoids tedious discretization of the total energy over staggered grids. A discrete kinetic energy balance is derived from the scheme and a source term is added in the discrete internal energy balance equation to preserve the exact total energy balance at the limit. High order methods of MUSCL type are used in the discrete convective operators, based solely on material velocity. They lead to positivity of density and internal energy under CFL conditions. This ensures that the total energy cannot grow and we can furthermore derive a discrete entropy inequality. Under stability assumptions of the discrete L8 and BV norms of the scheme's solutions one can prove that a sequence of converging discrete solutions necessarily converges towards the weak solution of the Euler system. Besides it satisfies a weak entropy inequality at the limit. Concerning the front propagation, we transform the flame front evolution equation (the so

  13. Search for solar axion emission from $^7$Li and D(p,$\\gamma)^3$He nuclear decays with the CAST $\\gamma$-ray calorimeter

    CERN Document Server

    Andriamonje, S.; Autiero, D.; Barth, K.; Belov, A.; Beltran, B.; Brauninger, H.; Carmona, J.M.; Cebrian, S.; Collar, J.I.; Dafni, T.; Davenport, M.; Di Lella, L.; Eleftheriadis, C.; Englhauser, J.; Fanourakis, G.; Ferrer-Ribas, E.; Fischer, H.; Franz, J.; Friedrich, P.; Geralis, T.; Giomataris, I.; Gninenko, S.; Gomez, H.; Hasinoff, M.; Heinsius, F.H.; Hoffmann, D.H.H.; Irastorza, I.G.; Jacoby, J.; Jakovcic, K.; Kang, D.; Konigsmann, K.; Kotthaus, R.; Krcmar, M.; Kousouris, K.; Kuster, M.; Lakic, B.; Lasseur, C.; Liolios, A.; Ljubicic, A.; Lutz, G.; Luzon, G.; Miller, D.W.; Morales, J.; Ortiz, A.; Papaevangelou, T.; Placci, A.; Raffelt, G.; Riege, H.; Rodriguez, A.; Ruz, J.; Savvidis, I.; Semertzidis, Y.; Serpico, P.; Stewart, L.; Vieira, J.D.; Villar, J.; Vogel, J.; Walckiers, L.; Zioutas, K.

    2010-01-01

    We present the results of a search for a high-energy axion emission signal from 7Li (0.478 MeV) and D(p,gamma)3He (5.5 MeV) nuclear transitions using a low-background gamma-ray calorimeter during Phase I of the CAST experiment. These so-called "hadronic axions" could provide a solution to the long-standing strong-CP problem and can be emitted from the solar core from nuclear M1 transitions. This is the first such search for high-energy pseudoscalar bosons with couplings to nucleons conducted using a helioscope approach. No excess signal above background was found.

  14. Excitation of the isomeric states 1h sub 1 sub 1 sub / sub 2 in the nuclear reactions with gamma-quanta, neutrons and at beta decay

    CERN Document Server

    Belov, A G; Melnikova, L M; Ponomarev, V Yu; Tsoneva, N; Stoyanov, C; Balabanov, N P; Tonchev, A P

    2001-01-01

    The isomeric ratios (IR) were measured in the isotones with N = 81 ( sup 1 sup 3 sup 5 Xe, sup 1 sup 3 sup 7 Ba, sup 1 sup 3 sup 9 Ce, sup 1 sup 4 sup 1 Nd, and sup 1 sup 4 sup 3 Sm). Isomers with J suppi 11/2 sup - were excited in the reactions (n, gamma), (gamma, n), and beta sup + decay of sup 1 sup 3 sup 9 Pr and sup 1 sup 4 sup 1 Pm. The activation methods of gamma-spectrum measurement of reaction products was used. The marked difference of IR was observed in the isotones with the different atomic numbers Z but in the same reactions. The calculations of IR using low-level spectrum of final nuclei and probability of radiation transitions on the base of the quasiparticle phonon model were performed. The satisfactory agreement of the measured and calculated IR was obtained for all studied isotopes. The dependence of IR on Z is explained by the different energy of reaction and different probability levels population of the activation

  15. Gluon fragmentation in T(1S) decays

    International Nuclear Information System (INIS)

    Bienlein, J.K.

    1983-05-01

    In T(1S) decays most observables (sphericity, charged multiplicity, photonic energy fraction, inclusive spectra) can be understood assuming that gluons fragment like quarks. New results from LENA use the (axis-independent) Fox-Wolfram moments for the photonic energy deposition. Continuum reactions show 'standard' Field-Feynman fragmentation. T(1S) decays show a significant difference in the photonic energy topology. It is more isotropic than with the Field-Feynman fragmentation scheme. Gluon fragmentation into isoscalar mesons (a la Peterson and Walsh) is excluded. But if one forces the leading particle to be isoscalar, one gets good agreement with the data. (orig.)

  16. Proceedings of the 13. Workshop on Nuclear Physics in Brazil

    International Nuclear Information System (INIS)

    1990-01-01

    Theoretical and experimental studies on nuclear structure, nuclear matter, scattering, nuclear reactions, radioactive decay, nuclear properties and nuclear models are presented. Studies on radiation protection, radiation detectors, spectroscopy and elementary particles area also presented. (M.C.K.)

  17. MODEL RADIOACTIVE RADON DECAY

    Directory of Open Access Journals (Sweden)

    R.I. Parovik

    2012-06-01

    Full Text Available In a model of radioactive decay of radon in the sample (222Rn. The model assumes that the probability of the decay of radon and its half-life depends on the fractal properties of the geological environment. The dependencies of the decay parameters of the fractal dimension of the medium.

  18. On-line nuclear orientation

    International Nuclear Information System (INIS)

    Krane, K.S.

    1990-01-01

    This grant has as its overall goal the pursuit of on-line nuclear orientation experiments for the purpose of eliciting details of nuclear structure from the decays of neutron-deficient nuclei, such as those produced by the Holifield Heavy-Ion Research Facility at Oak Ridge and extracted by the UNISOR Isotope Separator. This paper discusses: refrigerator development; the decay of 184 Au; the decay of 191 Hg to 191 Au; the decay of 189 Pt to 189 Ir; the decays of 109,111 Pd; the decay of 172 Er; and solid angle corrections

  19. Nuclear Reaction Data Centers

    International Nuclear Information System (INIS)

    McLane, V.; Nordborg, C.; Lemmel, H.D.; Manokhin, V.N.

    1988-01-01

    The cooperating Nuclear Reaction Data Centers are involved in the compilation and exchange of nuclear reaction data for incident neutrons, charged particles and photons. Individual centers may also have services in other areas, e.g., evaluated data, nuclear structure and decay data, reactor physics, nuclear safety; some of this information may also be exchanged between interested centers. 20 refs., 1 tab

  20. Nuclear theory progress report

    International Nuclear Information System (INIS)

    1991-01-01

    This report discusses research performed at University of Washington in nuclear theory. Some of the topics discussed are: nuclear astrophysics; symmetry; time reversal invariance; quark matter; superallowed beta decay; exclusive reactions; nuclear probes; soliton model; relativistic heavy ion collisions; supernova explosions; neutrino processes in dense matter; field theories; weak interaction physics; and nuclear structure

  1. Decay modes of high-lying excitations in nuclei

    International Nuclear Information System (INIS)

    Gales, S.

    1993-01-01

    Inelastic, charge-exchange and transfer reactions induced by hadronic probes at intermediate energies have revealed a rich spectrum of new high-lying modes embedded in the nuclear continuum. The investigation of their decay properties is believed to be a severe test of their microscopic structure as predicted by nuclear models. In addition the degree of damping of these simple modes in the nuclear continuum can be obtained by means of the measured branching ratios to the various decay channels as compared to statistical model calculations. As illustrative examples the decay modes of high-spin single-particle states and isovector resonances are discussed. (author) 23 refs.; 14 figs

  2. Integrated scheme of long-term for spent fuel management of power nuclear reactors; Esquema integrado de largo plazo para la administracion de combustible gastado de reactores nucleares de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez S, J. R.; Palacios H, J. C.; Martinez C, E., E-mail: ramon-ramirez@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2015-09-15

    After of irradiation of the nuclear fuel in the reactor core, is necessary to store it for their cooling in the fuel pools of the reactor. This is the first step in a processes series before the fuel can reach its final destination. Until now there are two options that are most commonly accepted for the end of the nuclear fuel cycle, one is the open nuclear fuel cycle, requiring a deep geological repository for the fuel final disposal. The other option is the fuel reprocessing to extract the plutonium and uranium as valuable materials that remaining in the spent fuel. In this study the alternatives for the final part of the fuel cycle, which involves the recycling of plutonium and the minor actinides in the same reactor that generated them are shown. The results shown that this is possible in a thermal reactor and that there are significant reductions in actinides if they are recycled into reactor fuel. (Author)

  3. Study on the aligned uranium-235 nuclear decay in the neutron energy range of 1.7 eV - 2.15 keV

    International Nuclear Information System (INIS)

    Danelyan, L.S.; Zakharov, Yu.V.; Zykov, V.M.; Mostovoj, V.I.; Stolyarov, V.A.; Biryukov, S.A.; Zysina, N.Yu.; Osochnikov, A.A.; Svettsov, A.V.

    1983-01-01

    Using a time-of-flight neutron spectrometer comparative measurements of intensity of fission reaction on the aligned and non-oriented uranium-235 nuclei have been performed in order to identify the resonances caused by p-neutron capture as well as to determine the p-neutron contribution to the fission cross section in the region of unresolved resonances. In some isolated resonances differences in cross sections on aligned and non-oriented nuclei of about 10% have been observed which can permit to assi.on them to p-resonances. In the region of unresolved resonances in the 0.15-2.15 keV neutron energy range to the accuracy +-1% no changes in the fission cross section during the nuclear alignment have been observ

  4. Comparative efficacy of ways of long-term usage of start-up boilers in the scheme of nuclear power plant

    Science.gov (United States)

    Khroustalev, V. A.; Simonyan, A. A.

    2017-11-01

    There was carried out an analysis of technical characteristics of boiler houses in a number of Russian NPPs. We justified the possibility of their usage for autonomous generation of electrical energy and improvement of maneuvering properties of power complexes as a single object of regulation, as well as the possibility of increasing the total generation capacity of NPP power units during peak hours. Then the selection of the main equipment of house boiler for its autonomous work was done. There were composed basic thermal diagrams of the power complex on the basis of NPP start-up boiler (SUB) and the satellite turbine. The article also considers some options of reconstruction of SUB into the heat-recovery boiler. The developed power complexes are designed to be used on the basis of the two-loop NPP with pressurized power reactors (PWR). They can be applied with serial and projected domestic NPP units with the aim of getting more power, improving the plant capacity factor (PCF), as well as with the aim of NPP participation in the regulation of the load curve above the nominal value with partial replacement of new construction. The power complexes can be a relevant solution in the light of the energy strategy of the Russian Federation, which is aimed at, firstly, further improvement of efficiency and safety at the NPP, and, secondly, solving the problem of adequate maneuverability and ensuring the adjustment range limits in power systems with high share of nuclear power plants. Implementation of new hybrid thermal diagrams allows simultaneous increase in the safety of NPP, and usage of nuclear power plants emergency frequency control in power systems by fast load drop and rise by -4÷+2 % of the nominal value. Due to the usage of different fuels in power complexes, uranium loading in the core of reactor facilities and gas in SUB, there was proposed and formalized the criterion of “thermoeconomic index”. This criterion represents the ratio of the gross receipt

  5. (EC+β+) decay of 130Ce

    International Nuclear Information System (INIS)

    Xu Shuwei; Zhang Tianmei; Xie Yuanxiang; Ma Ruichang; Ge Yuanxiu; Guo Yingxiang; Wang Chunfang; Li Zhankui; Guo Bing; Xing Jianping; Guo Tianrui; Zhu Shaofei; Xu Wang; Du Jinzhou

    1996-01-01

    The nuclide 130 Ce was produced by a ( 16 O, 4n) reaction on an enriched 118 Sn target. Reaction products were transported to a shielded location by using a helium-jet tape transport system. A 22.9 min activity in chemically separated cerium sample was identified as 130 Ce. The (EC+β + ) decay scheme of 130 Ce was proposed for the first time. This scheme includes 108 γ-lines, 107 γ-lines among them being new. More than 13 1 + low-lying states of 130 La are populated in the decay of 130 Ce. Two new isomers with half-life of 77±10 ns and 17±5 ns were observed by means of delayed γ-γ coincidence measurements. (orig.). With 5 figs., 3 tabs

  6. β decay studies of n-rich Cs isotopes with the ISOLDE Decay Station

    Science.gov (United States)

    Lică, R.; Benzoni, G.; Morales, A. I.; Borge, M. J. G.; Fraile, L. M.; Mach, H.; Madurga, M.; Sotty, C.; Vedia, V.; De Witte, H.; Benito, J.; Berry, T.; Blasi, N.; Bracco, A.; Camera, F.; Ceruti, S.; Charviakova, V.; Cieplicka-Oryńczak, N.; Costache, C.; Crespi, F. C. L.; Creswell, J.; Fernández-Martínez, G.; Fynbo, H.; Greenlees, P.; Homm, I.; Huyse, M.; Jolie, J.; Karayonchev, V.; Köster, U.; Konki, J.; Kröll, T.; Kurcewicz, J.; Kurtukian-Nieto, T.; Lazarus, I.; Leoni, S.; Lund, M.; Marginean, N.; Marginean, R.; Mihai, C.; Mihai, R.; Negret, A.; Orduz, A.; Patyk, Z.; Pascu, S.; Pucknell, V.; Rahkila, P.; Regis, J. M.; Rotaru, F.; Saed-Sami, N.; Sánchez-Tembleque, V.; Stanoiu, M.; Tengblad, O.; Thuerauf, M.; Turturica, A.; Van Duppen, P.; Warr, N.

    2017-05-01

    Neutron-rich Ba isotopes are expected to exhibit octupolar correlations, reaching their maximum in isotopes around mass A = 146. The odd-A neutron-rich members of this isotopic chain show typical patterns related to non-axially symmetric shapes, which are however less marked compared to even-A ones, pointing to a major contribution from vibrations. In the present paper we present results from a recent study focused on 148-150Cs β-decay performed at the ISOLDE Decay Station equipped with fast-timing detectors. A detailed analysis of the measured decay half-lives and decay scheme of 149Ba is presented, giving a first insight in the structure of this neutron-rich nucleus.

  7. Theoretical calculation of decay data of short-lived nuclides for JNDC FP decay data file

    International Nuclear Information System (INIS)

    Yoshida, Tadashi

    1983-08-01

    It is one of unique features of the JNDC FP Decay Data File that theoretical values of E-bar sub(β) and E-bar sub(γ), average beta- and gamma-ray energies, are fully adopted for short-lived nuclides. Here, details of the theoretical estimation method of E-bar sub(β) and E-bar sub(γ) based on 'gross theory' of beta-decay are described and the numerical tables of the estimated decay data for short-lived nuclides are presented. Further, discussion is made for justification of adoption of the theoretical values instead of values derived from decay schemes from the viewpoint of the energy profile of the beta-strength function. (author)

  8. Cluster aspects of alpha decay of heavy spherical nuclei

    International Nuclear Information System (INIS)

    Kadmenskij, S.G.; Furman, V.I.; Kholan, S.; Khlebostroev, V.G.

    1975-01-01

    On the basis of the non-R-Matrix approach to the α-decay theory the surface α-cluster model of α-decay is introduced. In the frame of this model evidence is obtained about an important contribution of the peripherical region of parent nuclei for the absolute α-decay widths. A classification of the α-transitions following the values of experimental probabilities for the existence of α-particles at the nuclear surface is performed

  9. Development of limiting decay heat values

    International Nuclear Information System (INIS)

    Khotylev, V.A.; Thompson, J.W.; Gibb, R.A.

    1999-01-01

    A number of tools are used in the assessment of decay heat during an outage of the CANDU-6. Currently, the technical basis for all of these tools is 'CANDU Channel Decay Power', Reference 1. The methods used in that document were limited to channel decay powers. However, for most outage support analysis, decay heat limits are based on bundle heats. Since the production of that document in 1977, new versions of codes, and updates of general-purpose and CANDU-specific libraries have become available. These tools and libraries have both a more formal technical basis than Reference 1, and also a more formal validation base. Using these tools it is now possible to derive decay heat with more specific input parameters, such as fuel composition, heat per unit of fuel, and irradiation history, and to assign systematically derived uncertainty allowances to such decay heat values. In particular, we sought to examine a broad range of likely bundle histories, and thus establish a set of limiting bundle decay beat values, that could serve as a bounding envelope for use in Nuclear Safety Analysis. (author)

  10. Beta decay of /sup 39/Cl

    International Nuclear Information System (INIS)

    Wang, G.; Warburton, E.K.; Alburger, D.E.

    1987-01-01

    The β decay of /sup 39/Cl, produced in the /sup 37/Cl(t,p)/sup 39/Cl reaction at E/sub t/ = 3.1 MeV, has been investigated with a Ge-NaI(Tl) Compton-suppression γ-ray spectrometer. Nineteen γ-ray transitions were observed, including 10 previously known. Precision energy measurements were carried out on six of the strongest lines. In the proposed decay scheme a weak new β-ray branch is established to the 2950-keV level of /sup 39/Ar, and the populations of /sup 39/Ar levels at 2093 and 2433 keV are accounted for by γ-ray decays from higher excited states. Spin-parity assignments are given

  11. Improved limits on beta(-) and beta(-) decays of Ca-48

    Czech Academy of Sciences Publication Activity Database

    Bakalyarov, A.; Balysh, A.; Barabash, AS.; Beneš, P.; Briancon, C.; Brudanin, V. B.; Čermák, P.; Egorov, V.; Hubert, F.; Hubert, P.; Korolev, NA.; Kosjakov, VN.; Kovalík, Alojz; Lebedev, NA.; Novgorodov, A. F.; Rukhadze, NI.; Štekl, NI.; Timkin, VV.; Veleshko, IE.; Vylov, T.; Umatov, VI.

    2002-01-01

    Roč. 76, č. 9 (2002), s. 545-547 ISSN 0021-3640 Institutional research plan: CEZ:AV0Z1048901 Keywords : beta decay * double beta decay * Ca-48 Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.483, year: 2002

  12. Decay heat predictions using JEF1

    International Nuclear Information System (INIS)

    Tobias, A.

    1986-11-01

    The first Joint Evaluated File (JEF1) of data for reactor calculations has been constructed under the auspices of the NEA Data Bank. The data available within JEF1 for the calculation of decay heat due to direct fission products has been examined and the evaluation procedures used to produce these data are described. Decay heat predictions using the JEF1 data have been compared with corresponding values obtained with the UK data files. Differences of up to a few percent are observed in the predictions for a fission pulse. These occur mainly at short cooling times and can be attributed to revised fission yield data. For practical applications the differences in integral predictions using JEF1 and UK data are shown to be much smaller. UK and JEF1 total decay heat predictions have also been compared with results of a least squares fit to measured data for both U235 and Pu239 and directly with results of measurements for U238 and Pu241. The principal decay heat nuclides at a cooling time of 1000 s were identified and it was found that, for a number of them, the decay characteristics had been determined from relatively few measurements. It was also shown that the decay data for these nuclides, present in both UK and JEF1 data libraries, offered scope for revision which would permit improvement in the agreement between measurement and prediction. As plans for JEF2 are prepared, consideration should be given to improve decay heat predictions. It has been shown that while there is a general requirement for further data on short lived nuclides there is also a specific need to re-examine experimentally the decay schemes of a number of fission products with effective half lives of around 1000 s. (author)

  13. Finite-volume scheme for anisotropic diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Es, Bram van, E-mail: bramiozo@gmail.com [Centrum Wiskunde & Informatica, P.O. Box 94079, 1090GB Amsterdam (Netherlands); FOM Institute DIFFER, Dutch Institute for Fundamental Energy Research, The Netherlands" 1 (Netherlands); Koren, Barry [Eindhoven University of Technology (Netherlands); Blank, Hugo J. de [FOM Institute DIFFER, Dutch Institute for Fundamental Energy Research, The Netherlands" 1 (Netherlands)

    2016-02-01

    In this paper, we apply a special finite-volume scheme, limited to smooth temperature distributions and Cartesian grids, to test the importance of connectivity of the finite volumes. The area of application is nuclear fusion plasma with field line aligned temperature gradients and extreme anisotropy. We apply the scheme to the anisotropic heat-conduction equation, and compare its results with those of existing finite-volume schemes for anisotropic diffusion. Also, we introduce a general model adaptation of the steady diffusion equation for extremely anisotropic diffusion problems with closed field lines.

  14. Rare Decays at LHCb

    Science.gov (United States)

    Hall, Sam

    2014-04-01

    Rare decays of beauty and charm hadrons provide an effective method of testing the Standard Model and probing possible new physics scenarios. The LHCb experiment has published a variety of interesting results in this field, some of which are presented here. In particular the measurements of the branching fractions of B(s)0 → μ+μ- which, in combination with CMS, resulted in the first observation of the Bs0 → μ+μ- decay. Other topics include searches for the rare decay D0 → μ+μ-, the lepton flavour violating decays B(s)0 → e±μ∓, and the observation of the ψ(4160) resonance in the region of low recoil in B+ → K+μ+μ- decay. New results on the angular analysis of the decay B0 → K*0μ+μ- with form factor independent observables are also shown.

  15. Status of μ decays

    International Nuclear Information System (INIS)

    Kinnison, W.W.

    1983-01-01

    A short theoretical review of the weak interaction is presented with particular emphasis on the implications to normal and rare muon decay processes. This review addresses the standard theory, left-right symmetry theories, theories with horizontal symmetries, and composite models. A survey of experiments currently in progress to study both rare and normal muon decays is then presented with particular emphasis on the Los Alamos high statistics muon decay experiment and its implications for left-right symmetric theories. 16 references

  16. Effective Majorana neutrino decay

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, Lucia [Instituto de Fisica, Facultad de Ingenieria,Universidad de la Republica, Montevideo (Uruguay); Romero, Ismael; Peressutti, Javier; Sampayo, Oscar A. [Universidad Nacional de Mar del Plata, Departamento de Fisica, Instituto de Investigaciones Fisicas de Mar del Plata (IFIMAR) CONICET, UNMDP, Mar del Plata (Argentina)

    2016-08-15

    We study the decay of heavy sterile Majorana neutrinos according to the interactions obtained from an effective general theory. We describe the two- and three-body decays for a wide range of neutrino masses. The results obtained and presented in this work could be useful for the study of the production and detection of these particles in a variety of high energy physics experiments and astrophysical observations. We show in different figures the dominant branching ratios and the total decay width. (orig.)

  17. Axigluon decays of toponium

    International Nuclear Information System (INIS)

    Faustov, R.N.; Vasilevskaya, I.G.

    1990-01-01

    Chiral-colour model predicts the existence of axigluons which is an octet of massive axial-vector gauge bosons. In this respect toponium decays into axigluons and gluons are of interest. The following toponium decays are considered: θ → Ag, θ → AAg, θ → ggg → AAg. The width of toponium S-state decays is calculated under various possible values of axigluon mass

  18. Establishment and Analysis of Nuclear Structure Data DB for Nuclear Safety Regulation Technique Applications

    International Nuclear Information System (INIS)

    Lee, Young Ouk; Yoo, Jae Kwon; Gil, Choong; Cho, Young Sik; Kim, Hyung Il; Kim, Jong Woon; Kwon, Duk Hee; Lee, Jong Hwa

    2013-10-01

    The contents of the project consisting of four research fields carried out are: Ο Installation of DB with nuclear structure/decay datasets - Setup a computer system for production of nuclear structure/decay data in ENSDF format - Production of nuclear structure/decay data in ENSDF format( 211 , 215 Po, 136 Cs) and setup a data converting system from ENSDF format to ENDF-6 format. Ο Computer simulation of nuclear decay and burnup using the ENSDF DB - Calculation of decay heats of the several radioactive nuclides with Geant4 - Burnup calculation with full decay chain using Monte Carlo method Ο Comparison and analysis of nuclear structure/decay and fission product yields data. - Acquisitions and Analyses of decay and fission yields data in ENDF-6 format - Research for theoretical evaluation method of fission product yields data. Ο Analysis of SCALE(ORIGEN-s, -ARP) libraries - Analysis of ORIGEN library structure of nuclear decay/yields data. - Methodological studies to improve nuclear decay/yield ORIGEN libraries by use of nuclear structure/yield data in ENDF-6 format. The results of this project will be a basis to establish the nuclear decay and fission yield data DB in Korea. Additionally, new decay and yield data can be immediately served for the users to utilize those data for nuclear research and/or development

  19. Nuclear fuels

    International Nuclear Information System (INIS)

    Gangwani, Saloni; Chakrabortty, Sumita

    2011-01-01

    Nuclear fuel is a material that can be consumed to derive nuclear energy, by analogy to chemical fuel that is burned for energy. Nuclear fuels are the most dense sources of energy available. Nuclear fuel in a nuclear fuel cycle can refer to the fuel itself, or to physical objects (for example bundles composed of fuel rods) composed of the fuel material, mixed with structural, neutron moderating, or neutron reflecting materials. Long-lived radioactive waste from the back end of the fuel cycle is especially relevant when designing a complete waste management plan for SNF. When looking at long-term radioactive decay, the actinides in the SNF have a significant influence due to their characteristically long half-lives. Depending on what a nuclear reactor is fueled with, the actinide composition in the SNF will be different. The following paper will also include the uses. advancements, advantages, disadvantages, various processes and behavior of nuclear fuels

  20. Nuclear chemistry

    International Nuclear Information System (INIS)

    Vertes, A.; Kiss, I.

    1987-01-01

    This book is an introduction to the application of nuclear science in modern chemistry. The first group of chapters discuss the basic phenomena and concepts of nuclear physics with emphasis on their relation to chemical problems, including the main properties and the composition of atomic nuclei, nuclear reactions, radioactive decay and interactions of radiation with matter. These chapters provide the basis for understanding the following chapters which encompass the wide scope of nuclear chemistry. The methods of the investigation of chemical structure based on the interaction of nuclear radiation with matter including positronium chemistry and other exotic atoms is elaborated in particular detail. Separate chapters are devoted to the use of radioactive tracers, the chemical consequences of nuclear processes (i.e. hot atom chemistry), radiation chemistry, isotope effects and their applications, and the operation of nuclear reactors. (Auth.)

  1. Nuclear chemistry

    International Nuclear Information System (INIS)

    Vertes, A.; Kiss, I.

    1987-01-01

    This book is an introduction to the application of nuclear science in modern chemistry. The first group of chapters discuss the basic phenomena and concepts of nuclear physics with emphasis on their relation to chemical problems, including the main properties and the composition of atomic nuclei, nuclear reactions, radioactive decay and interactions of radiation with matter. These chapters provide the basis for understanding the following chapters which encompass the wide scope of nuclear chemistry. The methods of the investigation of chemical structure based on the interaction of nuclear radiation with matter including positronium chemistry and other exotic atoms is elaborated in particular detail. Separate chapters are devoted to the use of radioactive tracers, the chemical consequences of nuclear processes (i.e. hot atom chemistry), radiation chemistry, isotope effects and their applications, and the operation of nuclear reactors

  2. Rare Kaon Decays

    International Nuclear Information System (INIS)

    Kudenko, Y.

    1999-01-01

    The past few years have seen an evolution in the study of rare K decays from a concentration on explicitly Standard Model (SM) violating decays such as K L 0 → μe, to one on SM-allowed but suppressed decays such as K → πν| ν, in which short-distance interactions are dominant. There are also a number of recent experimental and theoretical studies of long-distance-dominated decays, but they do not have space to cover these, with the exception of those that are needed in the discussion of the short-distance-dominated processes

  3. Deviations from exponential decay

    Science.gov (United States)

    Petridis, Athanasios; Staunton, Lawrence; Luban, Marshall; Vermedahl, Jon

    2003-10-01

    We study deviations from exponetial decay in cases when the initial wavefunction is set in a potential well and is not an eigenstate of this potential. We numerically solve the time-dependent Schroedinger equation and observe a decaying but oscillatory behavior of the survival probability. Analytical calculations have been performed proving that even in the case of a simple finite square-well potential deviations from exponential decay persist for large times. Possible explanations for the limiting exponential decay for many-particle systems are developed.

  4. Dense detector for baryon decay

    International Nuclear Information System (INIS)

    Courant, H.; Heller, K.; Marshak, M.L.; Peterson, E.A.; Ruddick, K.; Shupe, M.

    1981-01-01

    Our studies indicate that the dense detector represents a potentially powerful means to search for baryon decay and to study this process, if it occurs. The detector has good angular resolution and particle identification properties for both showering and non-showering events. Its energy resolution is particularly good for muons, but pion, electron and photon energies can also be measured with resolutions of at least 25 percent (standard deviation). The dense detector has strong logistical advantages over other proposed schemes. These advantages imply not only a lower cost but also faster construction and higher reliability. A particular advantage is that the dense detector can be prototyped in order to optimize its characteristics prior to the construction of a large module. Subsequent modules can also be added easily, while the initial detector continues operation

  5. Influence of pairing in double beta decay of 48Ca

    Indian Academy of Sciences (India)

    is the natural calculation scheme for this nucleus without truncation. Recently proposed GXPF1A two-body effective interaction has been successfully tested for the fp shell [31–33] to perform 2νββ decay calculations for 48Ca. Recently, Horoi. [30] gave the 2νββ decay matrix elements and half-lives of 48Ca using full fp shell.

  6. Decay studies of neutron deficient astatine isotopes, ch. 3

    International Nuclear Information System (INIS)

    Lingeman, E.W.A.

    1975-01-01

    The neutron deficient astatine isotopes were produced using 209 Bi( 3 He, xn) reactions; excitation functions were measured. Singles gamma-ray measurements and level schemes are presented for 207 At, 208 At and 209 At. Energies and relative intensities of gamma-rays belong to decays to Po isotopes are also reported. A special investigation on 206 Po decay was performed. (V.J.C.)

  7. Overview of nuclear data

    International Nuclear Information System (INIS)

    Firestone, R.B.

    2003-01-01

    For many years, nuclear structure and decay data have been compiled and disseminated by an International Network of Nuclear Structure and Decay Data (NSDD) evaluators under the auspices of the International Nuclear Data Committee (INDC) of the International Atomic Energy Agency (IAEA). In this lecture I will discuss the kinds of data that are available and describe various ways to obtain this information. We will learn about some of the publications that are available and Internet sources of nuclear data. You will be introduced to Isotope Explorer software for retrieving and displaying nuclear structure and radioactive decay data. The on-line resources Table of Radioactive Isotopes, PGAA Database Viewer, Nuclear Science Reference Search, Table of Isotopes Educational Website, and other information sources will be discussed. Exercises will be provided to increase your ability to understand, access, and use nuclear data

  8. Overview of nuclear data

    Energy Technology Data Exchange (ETDEWEB)

    Firestone, R.B.

    2003-06-30

    For many years, nuclear structure and decay data have been compiled and disseminated by an International Network of Nuclear Structure and Decay Data (NSDD) evaluators under the auspices of the International Nuclear Data Committee (INDC) of the International Atomic Energy Agency (IAEA). In this lecture I will discuss the kinds of data that are available and describe various ways to obtain this information. We will learn about some of the publications that are available and Internet sources of nuclear data. You will be introduced to Isotope Explorer software for retrieving and displaying nuclear structure and radioactive decay data. The on-line resources Table of Radioactive Isotopes, PGAA Database Viewer, Nuclear Science Reference Search, Table of Isotopes Educational Website, and other information sources will be discussed. Exercises will be provided to increase your ability to understand, access, and use nuclear data.

  9. Neutron β Decay: Status and Future of the Asymmetry Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Takeyasu M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2007-04-04

    With more intense sources of cold and ultracold neutrons becoming available and with improved experimental techniques being developed, determination of ΙVud l from neutron β decay with a similar precision to that from from superallowed β decays is within reach. Determination of IVud l from neutron β decay, free from nuclear corrections, holds the most promise for a further improvement of the determination of IVud l· The current and future neutron β decay correlation experiments including the UCNA experiment at Los Alamos National Laboratory are reviewed.

  10. Radioactive-nuclide decay data in science and technology

    International Nuclear Information System (INIS)

    Reich, C.W.; Helmer, R.G.

    1975-01-01

    The scope of ENDF/B has recently been expanded to include radioactive-nuclide decay data. In this paper, the content and organization of the decay data which are included in ENDF/B are presented and discussed. The application of decay data in a wide variety of nuclear-related activities is illustrated by a number of examples. Two items pointed up by the ENDF/B decay-data compilation effort are treated: the identification of deficiencies in the data; and the importance of a radioactive-nuclide metrology effort oriented toward supplying these needs in a systematic fashion. (3 figures, 1 table)

  11. Radioactive-nuclide decay data in science and technology

    International Nuclear Information System (INIS)

    Reich, C.W.; Helmer, R.G.

    1975-01-01

    The scope of ENDF/B has recently been expanded to include radioactive-nuclide decay data. In this paper, the content and organization of the decay data which are included in ENDF/B are presented and discussed. The application of decay data in a wide variety of nuclear-related activities is illustrated by a number of examples. Two items pointed up by the ENDF/B decay-data compilation effort are treated: the identification of deficiencies in the data; and the importance of a radioactive-nuclide metrology effort oriented toward supplying these needs in a systematic fashion. 3 figures, 2 tables

  12. Rare decays at LHCb

    CERN Document Server

    Adrover Pacheco, Cosme

    2012-01-01

    Rare decays are excellent tests to infer the presence of physics beyond the Standard Model (BSM), as they occur through processes prohibited at tree level in the SM. Any deviation from the SM prediction in branching fraction or angular distributions of such decays can lead to indications of new physics.

  13. Aspects of B decays

    International Nuclear Information System (INIS)

    Faller, Sven

    2011-01-01

    B-meson decays are a good probe for testing the flavour sector of the standard model of particle physics. The standard model describes at present all experimental data satisfactorily, although some ''tensions'' exist, i.e. two to three sigma deviations from the predictions, in particular in B decays. The arguments against the standard model are thus purely theoretical. These tensions between experimental data and theoretical predictions provide an extension of the standard model by new physics contributions. Within the flavour sector main theoretical uncertainties are related to the hadronic matrix elements. For exclusive semileptonic anti B → D (*) l anti ν decays QCD sum rule techniques, which are suitable for studying hadronic matrix elements, however, with substantial, but estimable hadronic uncertainties, are used. The exploration of new physics effects in B-meson decays is done in an twofold way. In exclusive semileptonic anti B → D (*) l anti ν decays the effect of additional right-handed vector as well as left- and right-handed scalar and tensor hadronic current structures in the decay rates and the form factors are studied at the non-recoil point. As a second approach one studied the non-leptonic B 0 s →J/ψφ and B 0 →J/ψK S,L decays discussing CP violating effects in the time-dependent decay amplitudes by considering new physics phase in the B 0 - anti B 0 mixing phase. (orig.)

  14. Multiple preequilibrium decay processes

    International Nuclear Information System (INIS)

    Blann, M.

    1987-11-01

    Several treatments of multiple preequilibrium decay are reviewed with emphasis on the exciton and hybrid models. We show the expected behavior of this decay mode as a function of incident nucleon energy. The algorithms used in the hybrid model treatment are reviewed, and comparisons are made between predictions of the hybrid model and a broad range of experimental results. 24 refs., 20 figs

  15. B decays to baryons

    Indian Academy of Sciences (India)

    We note that two-body decays to baryons are suppressed relative to three- and four-body decays. In most of these analyses, the invariant baryon–antibaryon mass shows an enhancement near the threshold. We propose a phenomenological interpretation of this quite common feature of hadronization to baryons.

  16. Chapter 3: Wood Decay

    Science.gov (United States)

    Dan Cullen

    2014-01-01

    A significant portion of global carbon is sequestered in forest systems. Specialized fungi have evolved to efficiently deconstruct woody plant cell walls. These important decay processes generate litter, soil bound humic substances, or carbon dioxide and water. This chapter reviews the enzymology and molecular genetics of wood decay fungi, most of which are members of...

  17. Cavities/Tooth Decay

    Science.gov (United States)

    ... a process that occurs over time. Here's how tooth decay develops: Plaque forms. Dental plaque is a clear sticky film that coats ... by a lack of saliva, which helps prevent tooth decay by washing away food and plaque from your teeth. Substances found in saliva also help counter the ...

  18. Nuclear Data Sheets for A = 93

    International Nuclear Information System (INIS)

    Baglin, Coral M.

    2011-01-01

    Nuclear structure data pertaining to all nuclei with mass number A=93 (Se, Br, Kr, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag) have been compiled and evaluated and incorporated into the ENSDF data file. This publication for A=93 supersedes the previous publication by C.M. Baglin, Nuclear Data Sheets80, 1 (1997) (literature cutoff date November 1996) and subsequent revisions by C.M. Baglin of the ENSDF files for 93Br and 93 Kr (literature cutoff 26 February 2001) and for 93 Rh (literature cutoff 27 February 2001); it includes all data available prior to 15 December 2010. Significant changes since prior evaluations include the following: 2010Hw03 identified several high-spin states in 93 Kr in 252 Cf SF decay; in addition to the many low-spin levels already known in 93 Rb from β - decay, several higher-spin states have now been identified in a 252 Cf SF decay study (2009Hw03); this SF decay has also been used to identify additional states in 93 Sr (2003Hw01) and the 238 U( 82 Se,Xγ) reaction (2007Bu35) has provided new information on 93 Y. (HI,xnγ) reaction studies have expanded our knowledge of the structure of 93 Zr (2002Fo03, 2005Pa48), 93 Nb (2007Wa45), 93 Mo (2005Fu01), 93 Tc (2003Ha22) and 93 Pd (2004So04,2004Ru02). Considerable information on 93 Nb was provided by a (p,2nγ) study (2010Or01, 2006Or09, 2007Or01). The level schemes of 93 Ru, 93 Rh and 93 Pd have undergone the most extensive revision thanks to studies of 93 Rh ε decay (2004De40), 94 Ag εp decay (2004Mu30) and 94 Ag p decay (2005Mu15, 2005Mu30), respectively. The half-life of the Zr member of this chain is of particular interest because of 93 Zr's large contribution to long-term activity of nuclear reactor waste and also due to its potential as a supernova chronometer. During 2010, two new well-documented measurements of T 1/2 ( 93 Zr) were published (2010Ya01 and 2010Ca01); one agrees well with an earlier, undocumented measurement but, unfortunately, the other is many standard deviations

  19. Decay of hypernuclei

    International Nuclear Information System (INIS)

    Bando, H.

    1985-01-01

    The pionic and non-mesonic decays of hypernuclei are discussed. In the first part, various decay processes which could be useful to obtain information of hypernuclear structure are discussed. The experimental data concerning the pionic and non-mesonic decays are discussed in the second part. As the experimental data, there are only few lifetime data and some crude data on the non-mesonic to π decay ratio. In the third and the fourth parts, some theoretical analyses are made on the pionic and the nonmesonic decays. DDHF calculation was performed for Λ and N systems by using Skyrme type ΛN and NN effective interactions. A suppression factor of the order of 10 -3 for A nearly equal 100 was obtained. (Aoki, K.)

  20. Tests of the standard electroweak model in beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Severijns, N.; Beck, M. [Universite Catholique de Louvain (UCL), Louvain-la-Neuve (Belgium); Naviliat-Cuncic, O. [Caen Univ., CNRS-ENSI, 14 (France). Lab. de Physique Corpusculaire

    2006-05-15

    We review the current status of precision measurements in allowed nuclear beta decay, including neutron decay, with emphasis on their potential to look for new physics beyond the standard electroweak model. The experimental results are interpreted in the framework of phenomenological model-independent descriptions of nuclear beta decay as well as in some specific extensions of the standard model. The values of the standard couplings and the constraints on the exotic couplings of the general beta decay Hamiltonian are updated. For the ratio between the axial and the vector couplings we obtain C{sub A},/C{sub V} = -1.26992(69) under the standard model assumptions. Particular attention is devoted to the discussion of the sensitivity and complementarity of different precision experiments in direct beta decay. The prospects and the impact of recent developments of precision tools and of high intensity low energy beams are also addressed. (author)

  1. Monopole excitation of nucleus in the bound muon decay

    International Nuclear Information System (INIS)

    Sabirov, B.M.; Abazov, V.M.; Kutuzov, S.A.

    1987-01-01

    The work is aimed at theoretical and experimental investigation into the possibility of nucleus excitation under the muon decay on mesic atom K-shell. The process of mesic atom formation is briefly considered. The stage of muon presence in the mesic atom orbit is completed by mesoatomic cascade, muon decay or muon nuclear capture. Recording of electron coincidences from decay of muon with nuclear transition γ-quanta makes up the base of experiment on the search for the nucleus excitation under the bound muon decay. Muon 158 Sm atom is considered in detail. The experimental data obtained allow one to ascertain the upper limit of probability of the first 152 SmO + level excitation under the bound muon decay W -3

  2. An attempt for revision of JNDC FP decay data file

    International Nuclear Information System (INIS)

    Katakura, Jun-ichi; Matsumoto, Zyun-itiro; Akiyama, Masatsugu; Yoshida, Tadashi; Nakasima, Ryozo.

    1984-06-01

    Some improvement of JNDC FP Decay Data File is tried by reexamining the decay scheme for several nuclides, since slight discrepancies are seen in detailed comparison of decay powers. As a results, it is found that the average beta- and gamma-energies should be modified for 88 Rb and 143 La among the nuclides reexamined in the present study. The JNDC file modified in 88 Rb and 143 La gives better agreement in most cases with experiments than the original JNDC file for cooling times longer than a few thousands seconds. However, the discrepancy for cooling times from a few hundreds to about 1500 seconds still remains. (author)

  3. Simulated progress in double-beta decay

    International Nuclear Information System (INIS)

    Miley, H.S.; Arthur, R.J.; Avignone, F.T.

    1993-09-01

    A Monte Carlo code has been developed to accurately simulate double-beta decay measurements. Coincident gamma rays, beta spectra, and angular correlations have been added to adequately simulate a complete 100 Mo nuclear decay and provide corrections to experimentally determined detector efficiencies. This code has been used to strip certain low-background spectra obtained in the Homestake gold mine in Lead, SD, for the purpose of extremely sensitive materials assay for the construction of new, large, enriched germanium detectors. Assays as low as 9 μBq/g of 210 Pb in lead shielding were obtained

  4. The Mawala irrigation scheme

    OpenAIRE

    de Bont, Chris

    2018-01-01

    This booklet was written to share research results with farmers and practitioners in Tanzania. It gives a summary of the empirical material collected during three months of field work in the Mawala irrigation scheme (Kilimanjaro Region), and includes maps, tables and photos. It describes the history of the irrigation scheme, as well current irrigation and farming practices. It especially focuses on the different kinds of infrastructural improvement in the scheme (by farmers and the government...

  5. Ionization by nuclear transitions

    International Nuclear Information System (INIS)

    Freedman, M.S.

    1975-01-01

    A phenomenological description of ionization events is given that applies to both shaking transitions of the composite nucleus-atom system and the process in which the charged particles emitted in a nuclear decay transfer energy by a relatively slow ''direct collision'' final state interaction with atomic electrons. Specific areas covered include shakeoff in internal conversion, shakeoff in electron capture, shakeoff in beta decay, and inner electron ejection in alpha decay. (5 figs., 1 table)

  6. Charm Decays at BABAR

    International Nuclear Information System (INIS)

    Charles, M.

    2004-01-01

    The results of several studies of charmed mesons and baryons at BABAR are presented. First, searches for the rare decays D 0 → l + l - are presented and new upper limits on these processes are established. Second, a measurement of the branching fraction of the isospin-violating hadronic decay D* s (2112) + → D s + π 0 relative to the radiative decay D* s (2112) + → D s + γ is made. Third, the decays of D* sJ (2317) + and D sJ (2460) + mesons are studied and ratios of branching fractions are measured. Fourth, Cabibbo-suppressed decays of the Λ c + are examined and their branching fractions measured relative to Cabibbo-allowed modes. Fifth, the Χ c 0 is studied through its decays to Χ - π + and (Omega) - K + ; in addition to measuring the ratio of branching fractions for Χ c 0 produced from the c(bar c) continuum, the uncorrected momentum spectrum is measured, providing clear confirmation of Χ c 0 production in B decays

  7. Isospin Mixing in Nuclei Around N ∼ Z and the Superallowed β-Decay

    International Nuclear Information System (INIS)

    Satula, W.; Dobaczewski, J.; Nazarewicz, W.; Rafalski, M.

    2011-01-01

    Theoretical approaches that use one-body densities as dynamical variables, such as Hartree-Fock or the density functional theory (DFT), break isospin symmetry both explicitly, by virtue of charge-dependent interactions, and spontaneously. To restore the spontaneously broken isospin symmetry, we implemented the isospin-projection scheme on top of the Skyrme-DFT approach. This development allows for consistent treatment of isospin mixing in both ground and exited nuclear states. In this study, we apply this method to evaluate the isospin impurities in ground states of even-even and odd-odd N ∼ Z nuclei. By including simultaneous isospin and angular-momentum projection, we compute the isospin-breaking corrections to the 0 + → 0 + superallowed β-decay. (authors)

  8. SYMPOSIUM: Rare decays

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    Late last year, a symposium entitled 'Rare Decays' attracted 115 participants to a hotel in Vancouver, Canada. These participants were particle physicists interested in checking conventional selection rules to look for clues of possible new behaviour outside today's accepted 'Standard Model'. For physicists, 'rare decays' include processes that have so far not been seen, explicitly forbidden by the rules of the Standard Model, or processes highly suppressed because the decay is dominated by an easier route, or includes processes resulting from multiple transitions

  9. Weak radiative hyperon decays

    International Nuclear Information System (INIS)

    Roberts, B.L.; Booth, E.C.; Gall, K.P.; McIntyre, E.K.; Miller, J.P.; Whitehouse, D.A.; Bassalleck, B.; Hall, J.R.; Larson, K.D.; Wolfe, D.M.; Fickinger, W.J.; Robinson, D.K.; Hallin, A.L.; Hasinoff, M.D.; Measday, D.F.; Noble, A.J.; Waltham, C.E.; Hessey, N.P.; Lowe, J.; Horvath, D.; Salomon, M.

    1990-01-01

    New measurements of the Σ + and Λ weak radiative decays are discussed. The hyperons were produced at rest by the reaction K - p → Yπ where Y = Σ + or Λ. The monoenergetic pion was used to tag the hyperon production, and the branching ratios were determined from the relative amplitudes of Σ + → pγ to Σ + → pπ 0 and Λ → nγ to Λ → nπ 0 . The photons from weak radiative decays and from π 0 decays were detected with modular NaI arrays. (orig.)

  10. Non-leptonic decays of beauty decays

    CERN Document Server

    Bigi, Ikaros I; Shifman, M; Uraltsev, N; Vainshtein, A I

    1994-01-01

    "Anyone who keeps the ability to see beauty never grows old" (Franz Kafka). In the last few years considerable progress has been achieved in our understanding of the decays of heavy flavour hadrons. One can now calculate inclusive transition rates in QCD proper through an expansion in inverse powers of the heavy flavour quark mass without recourse to phenomenological assumptions. The non-perturbative contributions are treated systematically in this way; they are found to produce corrections of order a few percent in beauty decays, i.e. typically somewhat smaller than the perturbative corrections. One finds, among other things: (a) The lifetime of $B^-$ mesons is predicted to be longer than that of $B^0$ mesons by several percent. (b) The QCD prediction for the semileptonic branching ratio of $B$ mesons appears to exceed present experimental values.

  11. Succesful labelling schemes

    DEFF Research Database (Denmark)

    Juhl, Hans Jørn; Stacey, Julia

    2001-01-01

    to carry out a campaign targeted at this segment. The awareness percentage is already 92 % and 67% of the respondents believe they know the meaning of the scheme. But it stands to reason to study whether the respondents actually know what the labelling scheme stands for or if they just think they do...

  12. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... leaving the nuclear medicine facility. Through the natural process of radioactive decay, the small amount of radiotracer ... possible charges you will incur. Web page review process: This Web page is reviewed regularly by a ...

  13. Measurement of nuclear moments and radii by collinear laser spectroscopy

    CERN Multimedia

    Geithner, W R; Lievens, P; Kotrotsios, G; Silverans, R; Kappertz, S

    2002-01-01

    %IS304 %title\\\\ \\\\Collinear laser spectroscopy on a fast beam has proven to be a widely applicable and very efficient tool for measurements of changes in mean square nuclear charge radii, nuclear spins, magnetic dipole and electric quadrupole moments. Recent developments of extremely sensitive non-optical detection schemes enabled for some elements the extension of the measurements towards the very short-lived isotopes in the far wings of the ISOLDE production curves. The gain in sensitivity opens up new perspectives, particularly for measurements on lighter nuclei whose ground-state properties can be interpreted by large scale microscopic calculations instead of the more phenomenologic models used for heavier nuclei.\\\\ \\\\ For the sequence of argon isotopes $^{32-40}$Ar and $^{46}$Ar isotope shifts and nuclear moments were measured by optical pumping followed by state selective collisional ionization and detection of the $\\beta$-decay. Similarly, the low-background $\\alpha$-detection was used to extend earlie...

  14. Adaptive protection scheme

    Directory of Open Access Journals (Sweden)

    R. Sitharthan

    2016-09-01

    Full Text Available This paper aims at modelling an electronically coupled distributed energy resource with an adaptive protection scheme. The electronically coupled distributed energy resource is a microgrid framework formed by coupling the renewable energy source electronically. Further, the proposed adaptive protection scheme provides a suitable protection to the microgrid for various fault conditions irrespective of the operating mode of the microgrid: namely, grid connected mode and islanded mode. The outstanding aspect of the developed adaptive protection scheme is that it monitors the microgrid and instantly updates relay fault current according to the variations that occur in the system. The proposed adaptive protection scheme also employs auto reclosures, through which the proposed adaptive protection scheme recovers faster from the fault and thereby increases the consistency of the microgrid. The effectiveness of the proposed adaptive protection is studied through the time domain simulations carried out in the PSCAD⧹EMTDC software environment.

  15. Decay ring design

    CERN Document Server

    Chancé, A; Bouquerel, E; Hancock, S; Jensen, E

    The study of the neutrino oscillation between its different flavours needs pureand very intense fluxes of high energy, well collimated neutrinos with a welldetermined energy spectrum. A dedicated machine seems to be necessarynowadays to reach the required flux. A new concept based on the β-decayof radioactive ions which were accelerated in an accelerator chain was thenproposed. After ion production, stripping, bunching and acceleration, the unstableions are then stored in a racetrack-shaped superconducting decay ring.Finally, the ions are accumulated in the decay ring until being lost. The incomingbeam is merged to the stored beam by using a specific RF system, whichwill be presented here.We propose here to study some aspects of the decay ring, such as its opticalproperties, its RF system or the management of the losses which occur in thering (mainly by decay or by collimation).

  16. Inflaton decay in supergravity

    International Nuclear Information System (INIS)

    Endo, M.; Takahashi, F.; Yanagida, T.T.; Tokyo Univ.

    2007-06-01

    We discuss inflaton decay in supergravity, taking account of the gravitational effects. It is shown that, if the inflaton has a nonzero vacuum expectation value, it generically couples to any matter fields that appear in the superpotential at the tree level, and to any gauge sectors through anomalies in the supergravity. Through these processes, the inflaton generically decays into the supersymmetry breaking sector, producing many gravitinos. The inflaton also directly decays into a pair of the gravitinos. We derive constraints on both inflation models and supersymmetry breaking scenarios for avoiding overproduction of the gravitinos. Furthermore, the inflaton naturally decays into the visible sector via the top Yukawa coupling and SU(3) C gauge interactions. (orig.)

  17. Streamer chamber: pion decay

    CERN Multimedia

    1992-01-01

    The real particles produced in the decay of a positive pion can be seen in this image from a streamer chamber. Streamer chambers consist of a gas chamber through which a strong pulsed electric field is passed, creating sparks as a charged particle passes through it. A magnetic field is added to cause the decay products to follow curved paths so that their charge and momentum can be measured.

  18. Aspects of B decays

    Energy Technology Data Exchange (ETDEWEB)

    Faller, Sven

    2011-03-04

    B-meson decays are a good probe for testing the flavour sector of the standard model of particle physics. The standard model describes at present all experimental data satisfactorily, although some ''tensions'' exist, i.e. two to three sigma deviations from the predictions, in particular in B decays. The arguments against the standard model are thus purely theoretical. These tensions between experimental data and theoretical predictions provide an extension of the standard model by new physics contributions. Within the flavour sector main theoretical uncertainties are related to the hadronic matrix elements. For exclusive semileptonic anti B {yields} D{sup (*)}l anti {nu} decays QCD sum rule techniques, which are suitable for studying hadronic matrix elements, however, with substantial, but estimable hadronic uncertainties, are used. The exploration of new physics effects in B-meson decays is done in an twofold way. In exclusive semileptonic anti B {yields} D{sup (*)}l anti {nu} decays the effect of additional right-handed vector as well as left- and right-handed scalar and tensor hadronic current structures in the decay rates and the form factors are studied at the non-recoil point. As a second approach one studied the non-leptonic B{sup 0}{sub s}{yields}J/{psi}{phi} and B{sup 0}{yields}J/{psi}K{sub S,L} decays discussing CP violating effects in the time-dependent decay amplitudes by considering new physics phase in the B{sup 0}- anti B{sup 0} mixing phase. (orig.)

  19. Tau decays into kaons

    International Nuclear Information System (INIS)

    Finkemeier, M.; Mirkes, E.

    1995-04-01

    Predictions for semi-leptonic decay rates of the τ lepton into two meson final states and three meson final states are derived. The hadronic matrix elements are expressed in terms of form factors, which can be predicted by chiral Lagrangians supplemented by informations about all possible low-lying resonances in the different channels. Isospin symmetry relations among the different final states are carefully taken into account. The calculated brancing ratios are compared with measured decay rates where data are available

  20. A decay heat removal methodology for reuseable orbital transfer vehicles

    Science.gov (United States)

    McDaniel, Patrick J.; Perkins, David R.

    1992-07-01

    Operation of a nuclear thermal rocket(NTR) as the propulsion system for a reusable orbital transfer vehicle has been considered. This application is the most demanding in terms of designing a multiple restart capability for an NTR. The requirements on a NTR cooling system associated with the nuclear decay heat stored during operation have been evaluated, specifically for a Particle Bed Reactor(PBR) configuration. A three mode method of operation has been identified as required to adequately remove the nuclear decay heat.

  1. Nuclear data newsletter. No. 33

    International Nuclear Information System (INIS)

    2002-03-01

    This issue announces the online and offline news concerning a workshop on nuclear structure and decay data evaluation, INDC reports, updated databases and libraries on CD-ROM. In includes announcements on development activities of IAEA in the field of nuclear data collections and relevant computer codes and lists selected reports and documents on nuclear data as well as cooperating nuclear data service centres

  2. Nuclear data newsletter. No. 7

    International Nuclear Information System (INIS)

    1984-12-01

    This issue lists new nuclear data libraries received by the IAEA Nuclear Data Section: JENDL-2; EXFOR-V; Atomic mass tables; ENDF/B-5; the ENDF/B processing codes; and nuclear data handbooks. The libraries are concerned with recommended heavy element radionuclide decay data; nuclear theory for applications; and charts of nuclides. A selection of new relevant documents is also listed

  3. Analysis of urban decay from low resolution satellite remote sensing ...

    African Journals Online (AJOL)

    This paper analyzed the spatial and temporal pattern of urban decay in different parts of a traditional organic city through data extracted from satellite remote sensing images. It analyzed temporal differences in urban quality in the city using uniform parameter of urban blight measurement. It presented a classification scheme ...

  4. LHCb: Search for CP violation in $D^+ \\to K^-K^+\\pi^+$ decays at LHCb

    CERN Multimedia

    Gordon, Hamish

    2012-01-01

    A model-independent search for direct CP violation in the Cabibbo suppressed decay $D^+ \\to K^-K^+\\pi^+$ in a sample of approximately 370,000 decays is described. The normalized Dalitz plot distributions for $D^+$ and $D^-$ are compared using four different binning schemes that are sensitive to different manifestations of CP violation. No evidence for CP asymmetry is found.

  5. Fundamentals of nuclear science and engineering

    CERN Document Server

    Shultis, J Kenneth

    2007-01-01

    FUNDAMENTAL CONCEPTS Modern Units The Atom Chart of Nuclides MODERN PHYSICS CONCEPTS The Special Theory of Relativity Radiation as Waves and Particles Quantum Mechanics Derivation of Some Special Relativity Results Solutions to Schrodinger's Wave Equation ATOMIC/NUCLEAR MODELS Development of the Modern Atom Model Models of the Nucleus NUCLEAR ENERGETICS Binding Energy Nucleon Separation Energy Nuclear Reactions Examples of Binary Nuclear Reactions Q-Value for a Reaction Conservation of Charge and the Calculation of Q-values Q-Value for reactions Producing Excited Nuclei RADIOACTIVITY Overview Types of Radioactive Decay Radioactive Decay Diagrams Energetics of Radioactive Decay Characteristics of Radioactive Decay Decay Dynamics Naturally Occurring Radionuclides Radiodating Radioactive Decay Data BINARY NUCLEAR REACTIONS Types of Binary Reactions Kinematics of Binary Two-Product Nuclear Reactions Reaction Threshold Energy Applications of Binary Kinematics Reactions...

  6. β decays on the rotational levels of the 5/2+[642] 169Yb band

    International Nuclear Information System (INIS)

    Dzhelepov, B.S.; Zhukovskij, N.N.; Shestopalova, S.A.

    1993-01-01

    Competing 169 Lu β decays into rotational levels of 5/2 + [642] 169 Yb band are considered. Schemes of resolved β decay into 3 levels of deformed nucleus rotational bands, γ transitions linked with excitation and discharge of 169 Yb 5/2, 7/2, 9/2, 5/2 + [642] levels are presented. Matrix elements of axial-vector decay are determined. Data on 12 γ transitions in 169 Lu are presented

  7. Beta decay of highly charged ions

    International Nuclear Information System (INIS)

    Litvinov, Yuri A; Bosch, Fritz

    2011-01-01

    Beta decay of highly charged ions has attracted much attention in recent years. An obvious motivation for this research is that stellar nucleosynthesis proceeds at high temperatures where the involved atoms are highly ionized. Another important reason is addressing decays of well-defined quantum-mechanical systems, such as one-electron ions where all interactions with other electrons are excluded. The largest modifications of nuclear half-lives with respect to neutral atoms have been observed in beta decay of highly charged ions. These studies can be performed solely at ion storage rings and ion traps, because there high atomic charge states can be preserved for extended periods of time (up to several hours). Currently, all experimental results available in this field originate from experiments at the heavy-ion complex GSI in Darmstadt. There, the fragment separator facility FRS allows the production and separation of exotic, highly charged nuclides, which can then be stored and investigated in the storage ring facility ESR. In this review, we present and discuss in particular two-body beta decays, namely bound-state beta decay and orbital electron capture. Although we focus on experiments conducted at GSI, we will also attempt to provide general requirements common to any other experiment in this context. Finally, we address challenging but not yet performed experiments and we give prospects for the new radioactive beam facilities, such as FAIR in Darmstadt, IMP in Lanzhou and RIKEN in Wako.

  8. Uncertainties in fission-product decay-heat calculations

    Energy Technology Data Exchange (ETDEWEB)

    Oyamatsu, K.; Ohta, H.; Miyazono, T.; Tasaka, K. [Nagoya Univ. (Japan)

    1997-03-01

    The present precision of the aggregate decay heat calculations is studied quantitatively for 50 fissioning systems. In this evaluation, nuclear data and their uncertainty data are taken from ENDF/B-VI nuclear data library and those which are not available in this library are supplemented by a theoretical consideration. An approximate method is proposed to simplify the evaluation of the uncertainties in the aggregate decay heat calculations so that we can point out easily nuclei which cause large uncertainties in the calculated decay heat values. In this paper, we attempt to clarify the justification of the approximation which was not very clear at the early stage of the study. We find that the aggregate decay heat uncertainties for minor actinides such as Am and Cm isotopes are 3-5 times as large as those for {sup 235}U and {sup 239}Pu. The recommended values by Atomic Energy Society of Japan (AESJ) were given for 3 major fissioning systems, {sup 235}U(t), {sup 239}Pu(t) and {sup 238}U(f). The present results are consistent with the AESJ values for these systems although the two evaluations used different nuclear data libraries and approximations. Therefore, the present results can also be considered to supplement the uncertainty values for the remaining 17 fissioning systems in JNDC2, which were not treated in the AESJ evaluation. Furthermore, we attempt to list nuclear data which cause large uncertainties in decay heat calculations for the future revision of decay and yield data libraries. (author)

  9. Threshold Signature Schemes Application

    Directory of Open Access Journals (Sweden)

    Anastasiya Victorovna Beresneva

    2015-10-01

    Full Text Available This work is devoted to an investigation of threshold signature schemes. The systematization of the threshold signature schemes was done, cryptographic constructions based on interpolation Lagrange polynomial, elliptic curves and bilinear pairings were examined. Different methods of generation and verification of threshold signatures were explored, the availability of practical usage of threshold schemes in mobile agents, Internet banking and e-currency was shown. The topics of further investigation were given and it could reduce a level of counterfeit electronic documents signed by a group of users.

  10. Flavor-changing Z0 decay

    International Nuclear Information System (INIS)

    Axelrod, A.

    1982-10-01

    Chapter I reviews the phenomenological situation. Simple estimates of various rates are also provided in order to convey the physical intuition necessary to guide one through the equations and numbers that follow. Chapter II presents technical aspects of the general flavor changing Z 0 decay calculation, with emphasis on the integration scheme used. Chapter III describes a number of nontrivial checks on the calculation that were performed. Chapter IV contains the entire general algebraic result for the decay rate. Chapter V describes numerical aspects of the computer evaluation, and discusses the parameter values used and the results for the three generation case. A similar presentation for the four generation case is given in Chapter VI. Chapter VII describes what experimentalists should look for in a semiquantitative way. Some possibilities for rate enhancement, and some related processes are mentioned in Chapter VIII

  11. Double beta decays and neutrino masses

    International Nuclear Information System (INIS)

    Ejiri, Hiro

    2006-01-01

    Neutrino-less double beta decays(0νββ) are of great interest for studying the Majorana nature of ν's and the absolute ν-mass scale. The present report is a brief review of the 0νββ studies with emphasis on future experiments with the mass sensitivity of an order of 25∼100 meV and on experimental probes for investigating 0νββ nuclear matrix elements

  12. Nuclear analytical chemistry

    International Nuclear Information System (INIS)

    Brune, D.; Forkman, B.; Persson, B.

    1984-01-01

    This book covers the general theories and techniques of nuclear chemical analysis, directed at applications in analytical chemistry, nuclear medicine, radiophysics, agriculture, environmental sciences, geological exploration, industrial process control, etc. The main principles of nuclear physics and nuclear detection on which the analysis is based are briefly outlined. An attempt is made to emphasise the fundamentals of activation analysis, detection and activation methods, as well as their applications. The book provides guidance in analytical chemistry, agriculture, environmental and biomedical sciences, etc. The contents include: the nuclear periodic system; nuclear decay; nuclear reactions; nuclear radiation sources; interaction of radiation with matter; principles of radiation detectors; nuclear electronics; statistical methods and spectral analysis; methods of radiation detection; neutron activation analysis; charged particle activation analysis; photon activation analysis; sample preparation and chemical separation; nuclear chemical analysis in biological and medical research; the use of nuclear chemical analysis in the field of criminology; nuclear chemical analysis in environmental sciences, geology and mineral exploration; and radiation protection

  13. Strength loss in decayed wood

    Science.gov (United States)

    Rebecca E. Ibach; Patricia K. Lebow

    2014-01-01

    Wood is a durable engineering material when used in an appropriate manner, but it is susceptible to biological decay when a log, sawn product, or final product is not stored, handled, or designed properly. Even before the biological decay of wood becomes visually apparent, the decay can cause the wood to become structurally unsound. The progression of decay to that...

  14. CP violation in B decay

    OpenAIRE

    Yamamoto, Hitoshi

    2001-01-01

    We review the physics of CP violation in B decays. After introducing the CKM matrix and how it causes CP violation, we cover three types of CP violation that can occur in B decays: CP violation in mixing, CP violation by mixing-decay interference, and CP violation in decay.

  15. Exchange effects in double beta decay

    International Nuclear Information System (INIS)

    Stephenson, G.J. Jr.; Goldman, T.; Maltman, K.R.; Schmidt, K.E.

    1988-01-01

    The motivation underlying the resurgence of interest in double beta decay is the hope that the observation of or limits on the 0-neutrino mode will provide information about the nature of the neutrino. This clearly requires confidence in the nuclear matrix elements involved in the transition. The shell model calculations do not agree well with the geochemical values for 130 Te, which has lead to a spate of papers offering specific fixes for the problem. In this contribution we shall not comment on any of the specific nuclear calculations, rather we make some remarks which should be relevant to any model calculation

  16. Neutrinos in Nuclear Physics

    Energy Technology Data Exchange (ETDEWEB)

    McKeown, Bob [bmck@jlab.org

    2015-06-01

    Since the discovery of nuclear beta decay, nuclear physicists have studied the weak interaction and the nature of neutrinos. Many recent and current experiments have been focused on the elucidation of neutrino oscillations and neutrino mass. The quest for the absolute value of neutrino mass continues with higher precision studies of the tritium beta decay spectrum near the endpoint. Neutrino oscillations are studied through measurements of reactor neutrinos as a function of baseline and energy. And experiments searching for neutrinoless double beta decay seek to discover violation of lepton number and establish the Majorana nature of neutrino masses.

  17. Tabled Execution in Scheme

    Energy Technology Data Exchange (ETDEWEB)

    Willcock, J J; Lumsdaine, A; Quinlan, D J

    2008-08-19

    Tabled execution is a generalization of memorization developed by the logic programming community. It not only saves results from tabled predicates, but also stores the set of currently active calls to them; tabled execution can thus provide meaningful semantics for programs that seemingly contain infinite recursions with the same arguments. In logic programming, tabled execution is used for many purposes, both for improving the efficiency of programs, and making tasks simpler and more direct to express than with normal logic programs. However, tabled execution is only infrequently applied in mainstream functional languages such as Scheme. We demonstrate an elegant implementation of tabled execution in Scheme, using a mix of continuation-passing style and mutable data. We also show the use of tabled execution in Scheme for a problem in formal language and automata theory, demonstrating that tabled execution can be a valuable tool for Scheme users.

  18. Verification of an objective analysis scheme

    International Nuclear Information System (INIS)

    Cats, G.J.; Haan, B.J. de; Hafkenscheid, L.M.

    1987-01-01

    An intermittent data assimilation scheme has been used to produce wind and precipitation fields during the 10 days after the explosion at the Chernobyl nuclear power plant on 25 April 1986. The wind fields are analyses, the precipitation fields have been generated by the forecast model part of the scheme. The precipitation fields are of fair quality. The quality of the wind fields has been monitored by the ensuing trajectories. These were found to describe the arrival times of radioactive air in good agreement with most observational data, taken all over Europe. The wind analyses are therefore considered to be reliable. 25 refs.; 13 figs

  19. Beta decay is 151Pr into levels in 151Nd

    International Nuclear Information System (INIS)

    Shibata, Michihiro; Ikuta, Tomohiko; Taniguchi, Akihiro

    1994-01-01

    The β-decay of 59 151 Pr 92 to the levels in 60 151 Nd 91 has been studied from the fission products of 235 U using an on-line isotope separator (KUR-ISOL). Gamma-rays and conversion electrons have been measured. Conversion coefficients have been determined for the first time. The precise decay scheme is proposed up to 2430 keV. The newly observed 65 γ-rays and 16 levels are incorporated in it. The deduced level scheme of 151 Nd was compared to the calculated level scheme on the basis of the rotation-vibration coupling model with a Nilsson potential. Low-lying levels were well reproduced by this model. (author)

  20. Measurements of α-decay half-lives at GSI

    Science.gov (United States)

    Nociforo, C.; Farinon, F.; Musumarra, A.; Bosch, F.; Boutin, D.; Del Zoppo, A.; Figuera, P.; Fisichella, M.; Geissel, H.; Knöbel, R.; Kojouharov, I.; Kozhuharov, C.; Kuboki, T.; Kurcewicz, J.; Litvinov, Yu A.; Mazzocco, M.; Motizuki, Y.; Nolden, F.; Ohstubo, T.; Ohkuma, Y.; Patyk, Z.; Pellegriti, M. G.; Pietri, S.; Podolyak, Z.; Prochazka, A.; Sanjari, M. S.; Scheidenberger, C.; Scuderi, V.; Sun, B.; Suzuki, T.; Torresi, D.; Weick, H.; Winfield, J. S.; Winckler, N.; Winkler, M.; Wollersheim, H. J.; Yamaguchi, T.

    2012-10-01

    One of the major problems in nuclear astrophysics concerns the estimation of electron screening effects on nuclear reaction rates. We have proposed investigating the electron screening effects of nuclear systems which decay via α-particles, using fragmented beams at relativistic energies produced at the present GSI FRS-ESR facility. By looking at the modification of the half-lives and Qα-value of highly charged emitters, we expect to estimate the electron screening energies.

  1. Measurements of α-decay half-lives at GSI

    International Nuclear Information System (INIS)

    Nociforo, C; Farinon, F; Bosch, F; Boutin, D; Geissel, H; Knöbel, R; Kojouharov, I; Kozhuharov, C; Kurcewicz, J; Litvinov, Yu A; Nolden, F; Musumarra, A; Del Zoppo, A; Figuera, P; Fisichella, M; Kuboki, T; Mazzocco, M; Motizuki, Y; Ohstubo, T; Ohkuma, Y

    2012-01-01

    One of the major problems in nuclear astrophysics concerns the estimation of electron screening effects on nuclear reaction rates. We have proposed investigating the electron screening effects of nuclear systems which decay via α-particles, using fragmented beams at relativistic energies produced at the present GSI FRS-ESR facility. By looking at the modification of the half-lives and Q α -value of highly charged emitters, we expect to estimate the electron screening energies.

  2. Scheme of energy utilities

    International Nuclear Information System (INIS)

    2002-04-01

    This scheme defines the objectives relative to the renewable energies and the rational use of the energy in the framework of the national energy policy. It evaluates the needs and the potentialities of the regions and preconizes the actions between the government and the territorial organizations. The document is presented in four parts: the situation, the stakes and forecasts; the possible actions for new measures; the scheme management and the regional contributions analysis. (A.L.B.)

  3. Future directions in nuclear data publication

    International Nuclear Information System (INIS)

    Firestone, R.B.; Chu, S.Y.F.; Ekstroem, L.P.; Nordberg, H.

    1997-01-01

    Rapid advances in computer based technologies provide enormous opportunities and great challenges to the way nuclear data is disseminated. Simple text databases and linear, command driven software are giving way to more complex, indexed databases and object-oriented, menu-driven applications. The Internet will clearly dominate dissemination of nuclear data in for foreseeable future, and CD-ROM technology (or similar high-density media) will replace hard-copy publication. The Isotopes Project has released Version 1.0 of VuENSDF, a versatile, 32-bit, C ++ , Internet enabled application for disseminating nuclear data. VuENSDF can automatically retrieve data over Internet; display decay scheme drawings, level tables, and references; and perform limited database searching of nuclear bands, transition coincidences, and reference authors. Version 2.0 of VuENSDF is being developed and will offer more complete database searches, plotting, and data entry utilities. The Isotopes Project has established a series of home pages on the WWW to provide data for various topics of nuclear physics. The group has also published a CD-ROM version of the Table of Isotopes using Adobe Acrobat software. Updated, Internet versions of the Table of Isotopes are planned. (author)

  4. Teaching nuclear science: A cosmological approach

    International Nuclear Information System (INIS)

    Viola, V.E.

    1994-01-01

    Theories of the origin of the chemical elements can be used effectively to provide a unifying theme in teaching nuclear phenomena to chemistry students. By tracing the element-producing steps that are thought to characterize the chemical evolution of the universe, one can introduce the basic principles of nuclear nomenclature, structure, reactions, energetics, and decay kinetics in a self-consistent context. This approach has the additional advantage of giving the student a feeling for the origin of the elements and their relative abundances in the solar system. Further, one can logically introduce all of the basic forces and particles of nature, as well as the many analogies between nuclear and atomic systems. The subjects of heavy-element synthesis, dating, and the practical applications of nuclear phenomena fit naturally in this scheme. Within the nucleosynthesis framework it is possible to modify the presentation of nuclear behavior to suit the audience--ranging from an emphasis on description for the beginning student to a quantitative theoretical approach for graduate students. The subject matter is flexible in that the basic principles can be condensed into a few lecture as part of a more general course of expanded into an entire course. The following sections describe this approach, with primary emphasis on teaching at the elementary level

  5. SMAFS, Steady-state analysis Model for Advanced Fuel cycle Schemes

    International Nuclear Information System (INIS)

    LEE, Kwang-Seok

    2006-01-01

    1 - Description of program or function: The model was developed as a part of the study, 'Advanced Fuel Cycles and Waste Management', which was performed during 2003-2005 by an ad-hoc expert group under the Nuclear Development Committee in the OECD/NEA. The model was designed for an efficient conduct of nuclear fuel cycle scheme cost analyses. It is simple, transparent and offers users the capability to track down the cost analysis results. All the fuel cycle schemes considered in the model are represented in a graphic format and all values related to a fuel cycle step are shown in the graphic interface, i.e., there are no hidden values embedded in the calculations. All data on the fuel cycle schemes considered in the study including mass flows, waste generation, cost data, and other data such as activities, decay heat and neutron sources of spent fuel and high-level waste along time are included in the model and can be displayed. The user can modify easily the values of mass flows and/or cost parameters and see the corresponding changes in the results. The model calculates: front-end fuel cycle mass flows such as requirements of enrichment and conversion services and natural uranium; mass of waste based on the waste generation parameters and the mass flow; and all costs. It performs Monte Carlo simulations with changing the values of all unit costs within their respective ranges (from lower to upper bounds). 2 - Methods: In Monte Carlo simulation, it is assumed that all unit costs follow a triangular probability distribution function, i.e., the probability that the unit cost has a value increases linearly from its lower bound to the nominal value and then decreases linearly to its upper bound. 3 - Restrictions on the complexity of the problem: The limit for the Monte Carlo iterations is the one of an Excel worksheet, i.e. 65,536

  6. Detailed source term estimation of the atmospheric release for the Fukushima Daiichi Nuclear Power Station accident by coupling simulations of an atmospheric dispersion model with an improved deposition scheme and oceanic dispersion model

    International Nuclear Information System (INIS)

    Katata, G.; Chino, M.; Kobayashi, T.

    2015-01-01

    Temporal variations in the amount of radionuclides released into the atmosphere during the Fukushima Daiichi Nuclear Power Station (FNPS1) accident and their atmospheric and marine dispersion are essential to evaluate the environmental impacts and resultant radiological doses to the public. In this paper, we estimate the detailed atmospheric releases during the accident using a reverse estimation method which calculates the release rates of radionuclides by comparing measurements of air concentration of a radionuclide or its dose rate in the environment with the ones calculated by atmospheric and oceanic transport, dispersion and deposition models. The atmospheric and oceanic models used are WSPEEDI-II (Worldwide version of System for Prediction of Environmental Emergency Dose Information) and SEA-GEARN-FDM (Finite difference oceanic dispersion model), both developed by the authors. A sophisticated deposition scheme, which deals with dry and fog-water depositions, cloud condensation nuclei (CCN) activation, and subsequent wet scavenging due to mixed-phase cloud microphysics (in-cloud scavenging) for radioactive iodine gas (I 2 and CH 3 I) and other particles (CsI, Cs, and Te), was incorporated into WSPEEDI-II to improve the surface deposition calculations. The results revealed that the major releases of radionuclides due to the FNPS1 accident occurred in the following periods during March 2011: the afternoon of 12 March due to the wet venting and hydrogen explosion at Unit 1, midnight of 14 March when the SRV (safety relief valve) was opened three times at Unit 2, the morning and night of 15 March, and the morning of 16 March. According to the simulation results, the highest radioactive contamination areas around FNPS1 were created from 15 to 16 March by complicated interactions among rainfall, plume movements, and the temporal variation of release rates. The simulation by WSPEEDI-II using the new source term reproduced the local and regional patterns of cumulative

  7. Detailed source term estimation of the atmospheric release for the Fukushima Daiichi Nuclear Power Station accident by coupling simulations of an atmospheric dispersion model with an improved deposition scheme and oceanic dispersion model

    Energy Technology Data Exchange (ETDEWEB)

    Katata, G.; Chino, M.; Kobayashi, T. [Japan Atomic Energy Agency (JAEA), Ibaraki (Japan); and others

    2015-07-01

    Temporal variations in the amount of radionuclides released into the atmosphere during the Fukushima Daiichi Nuclear Power Station (FNPS1) accident and their atmospheric and marine dispersion are essential to evaluate the environmental impacts and resultant radiological doses to the public. In this paper, we estimate the detailed atmospheric releases during the accident using a reverse estimation method which calculates the release rates of radionuclides by comparing measurements of air concentration of a radionuclide or its dose rate in the environment with the ones calculated by atmospheric and oceanic transport, dispersion and deposition models. The atmospheric and oceanic models used are WSPEEDI-II (Worldwide version of System for Prediction of Environmental Emergency Dose Information) and SEA-GEARN-FDM (Finite difference oceanic dispersion model), both developed by the authors. A sophisticated deposition scheme, which deals with dry and fog-water depositions, cloud condensation nuclei (CCN) activation, and subsequent wet scavenging due to mixed-phase cloud microphysics (in-cloud scavenging) for radioactive iodine gas (I{sub 2} and CH{sub 3}I) and other particles (CsI, Cs, and Te), was incorporated into WSPEEDI-II to improve the surface deposition calculations. The results revealed that the major releases of radionuclides due to the FNPS1 accident occurred in the following periods during March 2011: the afternoon of 12 March due to the wet venting and hydrogen explosion at Unit 1, midnight of 14 March when the SRV (safety relief valve) was opened three times at Unit 2, the morning and night of 15 March, and the morning of 16 March. According to the simulation results, the highest radioactive contamination areas around FNPS1 were created from 15 to 16 March by complicated interactions among rainfall, plume movements, and the temporal variation of release rates. The simulation by WSPEEDI-II using the new source term reproduced the local and regional patterns of

  8. Detailed source term estimation of the atmospheric release for the Fukushima Daiichi Nuclear Power Station accident by coupling simulations of an atmospheric dispersion model with an improved deposition scheme and oceanic dispersion model

    Science.gov (United States)

    Katata, G.; Chino, M.; Kobayashi, T.; Terada, H.; Ota, M.; Nagai, H.; Kajino, M.; Draxler, R.; Hort, M. C.; Malo, A.; Torii, T.; Sanada, Y.

    2015-01-01

    Temporal variations in the amount of radionuclides released into the atmosphere during the Fukushima Daiichi Nuclear Power Station (FNPS1) accident and their atmospheric and marine dispersion are essential to evaluate the environmental impacts and resultant radiological doses to the public. In this paper, we estimate the detailed atmospheric releases during the accident using a reverse estimation method which calculates the release rates of radionuclides by comparing measurements of air concentration of a radionuclide or its dose rate in the environment with the ones calculated by atmospheric and oceanic transport, dispersion and deposition models. The atmospheric and oceanic models used are WSPEEDI-II (Worldwide version of System for Prediction of Environmental Emergency Dose Information) and SEA-GEARN-FDM (Finite difference oceanic dispersion model), both developed by the authors. A sophisticated deposition scheme, which deals with dry and fog-water depositions, cloud condensation nuclei (CCN) activation, and subsequent wet scavenging due to mixed-phase cloud microphysics (in-cloud scavenging) for radioactive iodine gas (I2 and CH3I) and other particles (CsI, Cs, and Te), was incorporated into WSPEEDI-II to improve the surface deposition calculations. The results revealed that the major releases of radionuclides due to the FNPS1 accident occurred in the following periods during March 2011: the afternoon of 12 March due to the wet venting and hydrogen explosion at Unit 1, midnight of 14 March when the SRV (safety relief valve) was opened three times at Unit 2, the morning and night of 15 March, and the morning of 16 March. According to the simulation results, the highest radioactive contamination areas around FNPS1 were created from 15 to 16 March by complicated interactions among rainfall, plume movements, and the temporal variation of release rates. The simulation by WSPEEDI-II using the new source term reproduced the local and regional patterns of cumulative

  9. Decay of 49Cr

    International Nuclear Information System (INIS)

    Jackson, S.V.; Henry, E.A.; Meyer, R.A.

    1975-01-01

    For the decay of 49 Cr the intensities of the 1361-, 1423-, 1508-, 1514-, and 1570-keV γ rays are found to be 0.85, 0.19, 0.15, 0.49, and 0.37, respectively, relative to I/sub gamma/ = 1000 for the 90-keV γ ray. Four other previously reported γ rays are shown to be sum peaks or contaminants. The recalculated β-decay branches and logft values (in parentheses) for 49 Cr decay are ground state (5.51), 90.639- (4.94), 152.928- (4.74), 1514.5- (5.71), 1661.1- (6.06), 2181.7- (7.0), 2236- (6.6), and 2310-keV (7.1). The known 3/2 + level at 748 keV was not observed to be populated and a limit of logft > 9 was found for that level

  10. Suppressed Charmed B Decay

    Energy Technology Data Exchange (ETDEWEB)

    Snoek, Hella Leonie [Vrije Univ., Amsterdam (Netherlands)

    2009-06-02

    This thesis describes the measurement of the branching fractions of the suppressed charmed B0 → D*- a0+ decays and the non-resonant B0 → D*- ηπ+ decays in approximately 230 million Υ(4S) → B$\\bar{B}$ events. The data have been collected with the BABAR detector at the PEP-II B factory at the Stanford Linear Accelerator Center in California. Theoretical predictions of the branching fraction of the B0 → D*- a{sub 0}+ decays show large QCD model dependent uncertainties. Non-factorizing terms, in the naive factorization model, that can be calculated by QCD factorizing models have a large impact on the branching fraction of these decay modes. The predictions of the branching fractions are of the order of 10-6. The measurement of the branching fraction gives more insight into the theoretical models. In general a better understanding of QCD models will be necessary to conduct weak interaction physics at the next level. The presence of CP violation in electroweak interactions allows the differentiation between matter and antimatter in the laws of physics. In the Standard Model, CP violation is incorporated in the CKM matrix that describes the weak interaction between quarks. Relations amongst the CKM matrix elements are used to present the two relevant parameters as the apex of a triangle (Unitarity Triangle) in a complex plane. The over-constraining of the CKM triangle by experimental measurements is an important test of the Standard Model. At this moment no stringent direct measurements of the CKM angle γ, one of the interior angles of the Unitarity Triangle, are available. The measurement of the angle γ can be performed using the decays of neutral B mesons. The B0 → D*- a0+ decay is sensitive to the angle γ and, in comparison to the current decays that are being employed, could significantly

  11. Decay of superdeformed bands

    International Nuclear Information System (INIS)

    Carpenter, M.P.; Khoo, T.L.; Lauritsen, T.

    1995-01-01

    One of the major challenges in the study of superdeformation is to directly connect the large number of superdeformed bands now known to the yrast states. In this way, excitation energies, spins and parities can be assigned to the levels in the second well which is essential to establish the collective and single-particle components of these bands. This paper will review some of the progress which has been made to understand the decay of superdeformed bands using the new arrays including the measurement of the total decay spectrum and the establishment of direct one-step decays from the superdeformed band to the yrast line in 194 Hg. 42 refs., 5 figs

  12. Weak interactions: muon decay

    International Nuclear Information System (INIS)

    Sachs, A.M.; Sirlin, A.

    1975-01-01

    The traditional theory of the dominant mode of muon decay is presented, a survey of the experiments which have measured the observable features of the decay is given, and those things which can be learned about the parameters and nature of the theory from the experimental results are indicated. The following aspects of the theory of muon decay are presented first: general four-fermion theory, two-component theory of the neutrino, V--A theory, two-component and V--A theories vs general four-fermion theory, intermediate-boson hypothesis, radiative corrections, radiative corrections in the intermediate-boson theory, and endpoint singularities and corrections of order α 2 . Experiments on muon lifetime, isotropic electron spectrum, total asymmetry and energy dependence of asymmetry of electrons from polarized muons, and electron polarization are described, and a summary of experimental results is given. 7 figures, 2 tables, 109 references

  13. Nuclear Data Sheets for A=217

    Energy Technology Data Exchange (ETDEWEB)

    Kondev, F. G.; McCutchan, E. A.; Singh, B.; Banerjee, K.; Bhattacharya, S.; Chakraborty, A.; Garg, S.; Jovancevic, N.; Kumar, S.; Rathi, S. K.; Roy, T.; Lee, J.; Shearman, R.

    2018-01-01

    The evaluated spectroscopic data are presented for 12 known nuclides with A=217 (Tl, Pb, Bi, Po, At, Rn, Fr, Ra, Ac, Th, Pa, U). For Tl-217, Pb-217, Pa-217, and U-217 nuclei, only information on the ground state is available. Levels in Bi-217 are known only from isomer decay following fragmentation reaction and those in At-217 and Rn-217 only from the a decay of Fr-221 and Ra-221, respectively. High spin levels in Ra-217 are mainly from 1987SuZY and 2011MuZZ which are a lab report and thesis, respectively. Due to differences between these studies, further experimental study is needed to firmly establish the level scheme.This evaluation was carried out as part of a joint IAEA-ICTP workshop for Nuclear Structure and Decay Data, organized and hosted by the IAEA, Vienna and ICTP, Trieste, Aug 22 to Sept 2 2016. The evaluation work was coordinated by E.A. McCutchan (BNL). This work supersedes the previous previous A=217 evaluation (2003Ak06) by Y.A. Akovali.

  14. Nuclear structure research. Annual progress report

    International Nuclear Information System (INIS)

    Wood, J.L.

    1995-01-01

    The most significant development this year has been the realization of a method for estimating EO transition strength in nuclei and the prediction that the de-excitation (draining) of superdeformed bands must take place, at least in some cases, by strong EO transitions. A considerable effort has been devoted to planning the nuclear structure physics that will be pursued using the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge. A significant effort has been devoted to HRIBF target development. This is a critical component of the HRIBF project. Exhaustive literature searches have been made for a variety of target materials with emphasis on thermodynamic properties. Vapor pressure measurements have been carried out. Experimental data sets for radioactive decays in the very neutron-deficient Pr-Eu and Ir-Tl regions have been under analysis. These decay schemes constitute parts of student Ph.D. theses. These studies are aimed at elucidating the onset of deformation in the Pr-Sm region and the characteristics of shape coexistence in the Ir-Bi region. Further experiments on shape coexistence in the neutron-deficient Ir-Bi region are planned using α decay studies at the FMA at ATLAS. The first experiment is scheduled for later this year

  15. Nuclear Data Sheets for A=217

    Science.gov (United States)

    Kondev, F. G.; McCutchan, E. A.; Singh, B.; Banerjee, K.; Bhattacharya, S.; Chakraborty, A.; Garg, S.; Jovancevic, N.; Kumar, S.; Rathi, S. K.; Roy, T.; Lee, J.; Shearman, R.

    2018-01-01

    The evaluated spectroscopic data are presented for 12 known nuclides with A=217 (Tl, Pb, Bi, Po, At, Rn, Fr, Ra, Ac, Th, Pa, U). For 217Tl, 217Pb, 217Pa, and 217U nuclei, only information on the ground state is available. Levels in 217Bi are known only from isomer decay following fragmentation reaction and those in 217At and 217Rn only from the α decay of 221Fr and 221Ra, respectively. High spin levels in 217Ra are mainly from 1987SuZY and 2011MuZZ which are a lab report and thesis, respectively. Due to differences between these studies, further experimental study is needed to firmly establish the level scheme. This evaluation was carried out as part of a joint IAEA-ICTP workshop for Nuclear Structure and Decay Data, organized and hosted by the IAEA, Vienna and ICTP, Trieste, Aug 22 to Sept 2 2016. The evaluation work was coordinated by E.A. McCutchan (BNL). This work supersedes the previous previous A=217 evaluation (2003Ak06) by Y.A. Akovali.

  16. Evaluation of the separation and purification of 227Th from its decay progeny by anion exchange and extraction chromatography

    International Nuclear Information System (INIS)

    Ivanov, P.I.; Collins, S.M.; Es, E.M. van; García-Miranda, M.; Jerome, S.M.; Russell, B.C.

    2017-01-01

    Thorium-227 is currently undergoing evaluation as a potential radionuclide for targeted cancer therapy, and as such a high chemical purity of the material is required. To establish a reliable procedure for radiochemical isolation of 227 Th from the parent 227 Ac and decay progeny, which includes the radiotherapeutic 223 Ra, the performance of three different separation schemes based on ion-exchange and extraction chromatography have been evaluated. The results suggest that both ion exchange and extraction chromatographic techniques can be successfully used for the separation of 227 Th from its decay progeny, however extraction chromatographic resins demonstrate favourable performance in terms of Th recovery and purification from radionuclide impurities. - Highlights: • Development of a radiochemical separation of 227 Th from residual 227Ac as well as from decay progeny. • Evaluation of ion-exchange and extraction chromatography techniques. • TEVA resin demonstrates favourable performance in terms of Th recovery and purification. • Developed method is applicable to both nuclear medicine and environmental analysis.

  17. Do protons decay

    International Nuclear Information System (INIS)

    Litchfield, P.J.

    1984-09-01

    The experimental status of proton decay is reviewed after the Leipzig International conference, July 1984. A brief comparative description of the currently active experiments is given. From the overall samples of contained events it can be concluded that the experiments are working well and broadly agree with each other. The candidates for proton decay from each experiment are examined. Although several experiments report candidates at a higher rate than expected from background calculations, the validity of these calculations is still open to doubt. (author)

  18. BEH fermionic decays

    CERN Document Server

    Dell'Asta, Lidia; The ATLAS collaboration

    2016-01-01

    Since the discovery of a Higgs-like boson by the ATLAS and CMS experiments at the LHC, the emphasis has shifted towards measurements of its properties and the search in the less sensitive channels in order to determine whether the new particle is the Standard Model (SM) Higgs boson. Of particular importance is the direct observation of the coupling of the Higgs boson to fermions. In this presentation a review of ATLAS and CMS results in the search for the Higgs boson in muon, tau-lepton, b-quark pair decay channels will be given. Moreover, the searches for lepton flavor violating decays will be presented.

  19. The Decay Data Evaluation Project (DDEP) and the JEFF-3.3 radioactive decay data library: Combining international collaborative efforts on evaluated decay data

    Science.gov (United States)

    Kellett, Mark A.; Bersillon, Olivier

    2017-09-01

    The Decay Data Evaluation Project (DDEP), is an international collaboration of decay data evaluators formed with groups from France, Germany, USA, China, Romania, Russia, Spain and the UK, mainly from the metrology community. DDEP members have evaluated over 220 radionuclides, following an agreed upon methodology, including a peer review. Evaluations include all relevant parameters relating to the nuclear decay and the associated atomic processes. An important output of these evaluations are recommendations for new measurements, which can serve as a basis for future measurement programmes. Recently evaluated radionuclides include: 18F, 59Fe, 82Rb, 82Sr, 88Y, 90Y, 89Zr, 94mTc, 109Cd, 133Ba, 140Ba, 140La, 151Sm and 169Er. The DDEP recommended data have recently been incorporated into the JEFF-3.3 Radioactive Decay Data Library. Other sources of nuclear data include 900 or so radionuclides converted from the Evaluated Nuclear Structure Data File (ENSDF), 500 from two UK libraries (UKPADD6.12 and UKHEDD2.6), the IAEA Actinide Decay Data Library, with the remainder converted from the NUBASE evaluation of nuclear properties. Mean decay energies for a number of radionuclides determined from total absorption gamma-ray spectroscopy (TAGS) have also been included, as well as more recent European results from TAGS measurements performed at the University of Jyväskylä by groups from the University of Valencia, Spain and SUBATECH, the University of Nantes, France. The current status of the DDEP collaboration and the JEFF Radioactive Decay Data Library will be presented. Note to the reader: the pdf file has been changed on September 22, 2017.

  20. Neutrinoless double beta decay in chiral effective field theory: lepton number violation at dimension seven

    Science.gov (United States)

    Cirigliano, V.; Dekens, W.; de Vries, J.; Graesser, M. L.; Mereghetti, E.

    2017-12-01

    We analyze neutrinoless double beta decay (0 νββ) within the framework of the Standard Model Effective Field Theory. Apart from the dimension-five Weinberg operator, the first contributions appear at dimension seven. We classify the operators and evolve them to the electroweak scale, where we match them to effective dimension-six, -seven, and -nine operators. In the next step, after renormalization group evolution to the QCD scale, we construct the chiral Lagrangian arising from these operators. We develop a power-counting scheme and derive the two-nucleon 0 νββ currents up to leading order in the power counting for each lepton-number-violating operator. We argue that the leading-order contribution to the decay rate depends on a relatively small number of nuclear matrix elements. We test our power counting by comparing nuclear matrix elements obtained by various methods and by different groups. We find that the power counting works well for nuclear matrix elements calculated from a specific method, while, as in the case of light Majorana neutrino exchange, the overall magnitude of the matrix elements can differ by factors of two to three between methods. We calculate the constraints that can be set on dimension-seven lepton-number-violating operators from 0 νββ experiments and study the interplay between dimension-five and -seven operators, discussing how dimension-seven contributions affect the interpretation of 0 νββ in terms of the effective Majorana mass m ββ .

  1. Meson exchange currents and two neutrino double beta decay

    International Nuclear Information System (INIS)

    Simkovic, F.

    1995-01-01

    By using a field theory approach a detailed analysis of the two neutrino double beta decay amplitude has been performed. We have shown that the summation over the intermediate nuclear states in the present two neutrino double beta decay studies corresponds to a summation over a class of meson exchange diagrams. We offer some arguments showing that the two nucleon mechanism considered at present does not provide the main contribution to the two neutrino double beta decay amplitude. A new electron-gamma exchange mechanism for this process is suggested. 31 refs., 1 fig

  2. Sensitivity and uncertainty analysis for fission product decay heat calculations

    International Nuclear Information System (INIS)

    Rebah, J.; Lee, Y.K.; Nimal, J.C.; Nimal, B.; Luneville, L.; Duchemin, B.

    1994-01-01

    The calculated uncertainty in decay heat due to the uncertainty in basic nuclear data given in the CEA86 Library, is presented. Uncertainties in summation calculation arise from several sources: fission product yields, half-lives and average decay energies. The correlation between basic data is taken into account. The uncertainty analysis were obtained for thermal-neutron-induced fission of U235 and Pu239 in the case of burst fission and irradiation time. The calculated decay heat in this study is compared with experimental results and with new calculation using the JEF2 Library. (from authors) 6 figs., 19 refs

  3. Introduction to nuclear physics

    International Nuclear Information System (INIS)

    Lee, Young Sun

    1987-03-01

    This book deals with nuclear physics with basic introduction, like atomic theory of material, movement theory of material, an atom, natural radioactivity, nuclear atom, electromagnetic waves, X rays, the quantum theory, special commercial theory, wavelength and particle, spectrum and hydrogen atom, meaning of wavelength driven, optics spectrum and electronic distribution, microstructure and Zeeman's effect, X rays spectrum and atom structure, an atomic nucleus, conversion rule of a radioactive element, properties of radiation and interaction with material, artificial nuclear decay and artificial radioactivity, acceleration of electric charge particle, neutron physics, nuclear fission, nuclear fission reactor and a thermonuclear reaction and nuclear fusion.

  4. Studying radiative B decays with the Atlas detector

    International Nuclear Information System (INIS)

    Viret, S.

    2004-09-01

    This thesis is dedicated to the study of radiative B decays with the ATLAS detector at the LHC (large hadron collider). Radiative decays belong to the rare decays family. Rare decays transitions involve flavor changing neutral currents (for example b → sγ), which are forbidden at the lowest order in the Standard Model. Therefore these processes occur only at the next order, thus involving penguin or box diagrams, which are very sensitive to 'new physics' contributions. The main goal of our study is to show that it would be possible to develop an online selection strategy for radiative B decays with the ATLAS detector. To this end, we have studied the treatment of low energy photons by the ATLAS electromagnetic calorimeter (ECal). Our analysis shows that ATLAS ECal will be efficient with these particles. This property is extensively used in the next section, where a selection strategy for radiative B decays is proposed. Indeed, we look for a low energy region of interest in the ECal as soon as the level 1 of the trigger. Then, photon identification cuts are performed in this region at level 2. However, a large part of the proposed selection scheme is also based on the inner detector, particularly at level 2. The final results show that large amounts of signal events could be collected in only one year by ATLAS. A preliminary significance (S/√B) estimation is also presented. Encouraging results concerning the observability of exclusive radiative B decays are obtained. (author)

  5. Upsilon family decays

    Energy Technology Data Exchange (ETDEWEB)

    Coyne, D.G.

    1984-10-01

    Selected topics in the investigations of decays of members of the Upsilon family are examined; the confrontation of theory with experiment is not yet adequate. The current evidence regarding the zeta(8322 MeV) is reviewed and future directions of study are indicated. 15 references.

  6. Unparticles and muon decay

    International Nuclear Information System (INIS)

    Choudhury, Debajyoti; Ghosh, Dilip Kumar; Mamta

    2008-01-01

    Recently Georgi has discussed the possible existence of 'Unparticles' describable by operators having non-integral scaling dimensions. With the interaction of these with the Standard Model particles being constrained only by gauge and Lorentz symmetries, it affords a new source for lepton flavour violation. Current and future muon decay experiments are shown to be very sensitive to such scenarios

  7. Unparticles and muon decay

    Energy Technology Data Exchange (ETDEWEB)

    Choudhury, Debajyoti [Department of Physics and Astrophysics, University of Delhi, Delhi 110 007 (India); Ghosh, Dilip Kumar [Department of Physics and Astrophysics, University of Delhi, Delhi 110 007 (India)], E-mail: dkghosh@physics.du.ac.in; Mamta [Department of Physics, S.G.T.B. Khalsa College, University of Delhi, Delhi 110 007 (India)

    2008-01-03

    Recently Georgi has discussed the possible existence of 'Unparticles' describable by operators having non-integral scaling dimensions. With the interaction of these with the Standard Model particles being constrained only by gauge and Lorentz symmetries, it affords a new source for lepton flavour violation. Current and future muon decay experiments are shown to be very sensitive to such scenarios.

  8. On the proton decay

    International Nuclear Information System (INIS)

    Fonda, L.; Ghirardi, G.C.; Weber, T.

    1983-07-01

    The problem of the proton decay is considered taking into account that in actual experiments there is an interaction of the proton with its environment which could imply an increase of its theoretical lifetime. It is seen that, by application of the time-energy uncertainty relation, no prolongation of the lifetime is obtained in this case. (author)

  9. B decays and supersymmetry

    Indian Academy of Sciences (India)

    be quantified later. All SUSY models available in the market can be divided into two broad categories: R- .... β. ¼ =β +φSUSY, α. ¼ =α φSUSY. (2) so that their sum remains unchanged. γ measured from Bs decays will also be changed by a different amount, and hence the unitarity triangle (UT) will not close: this is the signal.

  10. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    2012-10-06

    Oct 6, 2012 ... 2003 [13], the measured averaged 2νββ-decay half-lives as recommended in [14] plus the recent measurement of 136Xe [15,24]. The last column shows the experiments addressing the measurement of the corresponding isotope. For some experiments, only the 'default' isotope is mentioned as they have ...

  11. B decays to baryons

    Indian Academy of Sciences (India)

    2012-11-10

    Nov 10, 2012 ... Figure 3. Effective Feynman diagrams for the initial meson–meson configuration. Figure 4. Effective Feynman diagrams for the initial diquark–antidiquark configuration. explain the absence of a threshold enhancement in B decays to baryons. There, all con- tributing Feynman diagrams are divided into two ...

  12. Herman Feshbach Prize in Theoretical Nuclear Physics Xiangdong Ji, University of Maryland PandaX-III: high-pressure gas TPC for Xe136 neutrinoless double beta decay at CJPL

    Science.gov (United States)

    Ji, Xiangdong; PandaX-III Collaboration

    2016-03-01

    The PandaX-III in China's Jinping Underground Lab is a new neutrinoless double beta decay experiment using Xe136 high-pressure gas TPC. The first phase of the experiment uses a 4 m3 gas detector with symmetric Micromegas charge readout planes. The gas TPC allows full reconstruction of the event topology, capable of distinguishing the two electron events from gamma background with high confidence level. The energy resolution can reach about 3% FWHM at the beta decay Q-value. The detector construction and the experimental lab is currently under active development. In this talk, the current status and future plan are reported.

  13. Compact Spreader Schemes

    Energy Technology Data Exchange (ETDEWEB)

    Placidi, M.; Jung, J. -Y.; Ratti, A.; Sun, C.

    2014-07-25

    This paper describes beam distribution schemes adopting a novel implementation based on low amplitude vertical deflections combined with horizontal ones generated by Lambertson-type septum magnets. This scheme offers substantial compactness in the longitudinal layouts of the beam lines and increased flexibility for beam delivery of multiple beam lines on a shot-to-shot basis. Fast kickers (FK) or transverse electric field RF Deflectors (RFD) provide the low amplitude deflections. Initially proposed at the Stanford Linear Accelerator Center (SLAC) as tools for beam diagnostics and more recently adopted for multiline beam pattern schemes, RFDs offer repetition capabilities and a likely better amplitude reproducibility when compared to FKs, which, in turn, offer more modest financial involvements both in construction and operation. Both solutions represent an ideal approach for the design of compact beam distribution systems resulting in space and cost savings while preserving flexibility and beam quality.

  14. Compact spreader schemes

    Energy Technology Data Exchange (ETDEWEB)

    Placidi, M.; Jung, J.-Y.; Ratti, A.; Sun, C., E-mail: csun@lbl.gov

    2014-12-21

    This paper describes beam distribution schemes adopting a novel implementation based on low amplitude vertical deflections combined with horizontal ones generated by Lambertson-type septum magnets. This scheme offers substantial compactness in the longitudinal layouts of the beam lines and increased flexibility for beam delivery of multiple beam lines on a shot-to-shot basis. Fast kickers (FK) or transverse electric field RF Deflectors (RFD) provide the low amplitude deflections. Initially proposed at the Stanford Linear Accelerator Center (SLAC) as tools for beam diagnostics and more recently adopted for multiline beam pattern schemes, RFDs offer repetition capabilities and a likely better amplitude reproducibility when compared to FKs, which, in turn, offer more modest financial involvements both in construction and operation. Both solutions represent an ideal approach for the design of compact beam distribution systems resulting in space and cost savings while preserving flexibility and beam quality.

  15. Classification of decays involving variable decay chains with convolutional architectures

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    Vidyo contribution We present a technique to perform classification of decays that exhibit decay chains involving a variable number of particles, which include a broad class of $B$ meson decays sensitive to new physics. The utility of such decays as a probe of the Standard Model is dependent upon accurate determination of the decay rate, which is challenged by the combinatorial background arising in high-multiplicity decay modes. In our model, each particle in the decay event is represented as a fixed-dimensional vector of feature attributes, forming an $n \\times k$ representation of the event, where $n$ is the number of particles in the event and $k$ is the dimensionality of the feature vector. A convolutional architecture is used to capture dependencies between the embedded particle representations and perform the final classification. The proposed model performs outperforms standard machine learning approaches based on Monte Carlo studies across a range of variable final-state decays with the Belle II det...

  16. Total Absorption Spectroscopy study of the 152Yb decay

    International Nuclear Information System (INIS)

    Estevez, M.E.; Algora, A.; Rubio, B.; Bernabeu, J.; Nacher, E.; Gadea, A.; Tain, J.L.; Cano, D.; Batist, L.; Burkard, K.

    2008-01-01

    Complete text of publication follows. The study of neutrino oscillation phenomena, which could open the possibility for Charge Conjugation-Parity violation in the lepton sector, is one of the most exciting problems in physics. In the appearance probability for neutrino oscillations, the CP-even terms and the CP-odd terms have different energy dependence, so the control of the neutrino beam energy has an added value. To study these topics, the construction of a monochromatic neutrino beam facility has been proposed recently. As a source for this beam, accelerated nuclei that decay through electron capture (EC) in a storage ring with long straight sections could be used. In a recent annual report, a preliminary study of the candidate nucleus 152 Yb was discussed. In this report we present the results of the Total Absorption Spectroscopy (TAS) analysis of these data. In the analysis, a coincidence between the X ray of 152 Tm (produced in the EC process) and the TAS spectrum is required. In the gated TAS spectrum the peaks are identified with levels fed in the decay, but it can also have contributions from contaminants and background, and it is modified by the detector response. The relation between the gated TAS spectrum and the feeding is: di = Σ j=1 jmax R ij f j , where d i is the number of counts in channel i of the measured spectrum, f j is the feeding to level j, and R ij is the probability that feeding to E j , gives counts on channel i of the measured spectrum. R is called the 'Response Function' of the detector, and depends on the decay scheme and on the detector. It was calculated by means of Montecarlo simulations. The problem of finding the feedings is reduced to solve this equation, for which the 'Expectation- Maximization Method' was used. It was shown that this algorithm is a very effective way to solve the TAS inverse problem. It is known that in some cases, the high resolution (HR) technique assigns incorrectly more feeding to low lying energy levels

  17. A classification scheme for LWR fuel assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Moore, R.S.; Williamson, D.A.; Notz, K.J.

    1988-11-01

    With over 100 light water nuclear reactors operating nationwide, representing designs by four primary vendors, and with reload fuel manufactured by these vendors and additional suppliers, a wide variety of fuel assembly types are in existence. At Oak Ridge National Laboratory, both the Systems Integration Program and the Characteristics Data Base project required a classification scheme for these fuels. This scheme can be applied to other areas and is expected to be of value to many Office of Civilian Radioactive Waste Management programs. To develop the classification scheme, extensive information on the fuel assemblies that have been and are being manufactured by the various nuclear fuel vendors was compiled, reviewed, and evaluated. It was determined that it is possible to characterize assemblies in a systematic manner, using a combination of physical factors. A two-stage scheme was developed consisting of 79 assembly types, which are grouped into 22 assembly classes. The assembly classes are determined by the general design of the reactor cores in which the assemblies are, or were, used. The general BWR and PWR classes are divided differently but both are based on reactor core configuration. 2 refs., 15 tabs.

  18. Complete correlation studies of two-proton decays: 6Be and 45Fe

    International Nuclear Information System (INIS)

    Grigorenko, L.; Wiser, T.D.; Miernik, K.; Charity, R.J.; Pfutzner, M.; Banu, A.; Bingham, C.R.; Cwiok, Mikolaj; Darby, Iain; Dominik, W.; Elson, J.M.; Ginter, T.N.; Grzywacz, R.; Janas, Z.; Karny, M.; Korgul, A.; Liddick, Sean; Mercurio, K.; Rajabali, Mustafa; Rykaczewski, Krzysztof Piotr; Shane, R.; Sobotka, L.G.; Stolz, A.; Trache, L.; Tribble, R.E.; Wuosmaa, A.H.; Zhukov, M.V.

    2009-01-01

    The complete three-body correlation pictures are experimentally reconstructed for the two-proton decays of the 6Be and 45Fe ground states. We are able to see qualitative similarities and differences between these decays. They demonstrate very good agreement with the predictions of a theoretical three-body cluster model. Validity of the theoretical methods for treatment of the three-body Coulombic decays of this class is thus established by the broad range of lifetimes and nuclear masses spanned by these cases. Implementations for decay dynamics and nuclear structure of 2p emitters are discussed.

  19. Charmless Hadronic Beauty Decays at LHCb

    Science.gov (United States)

    Williams, Timothy

    2017-10-01

    A summary of six LHCb results on the topic of charmless hadronic b-hadron decays is presented. These are comprised of: a search for the decay and updated branching fraction measurements of decays (h=K,π) [1]; the first observation of the decays and strong evidence for the decay [2]; the first observation of the decay [3]; a search for the decay [4]; the first observation of the decay [5] and evidence for CP-violation in decays [6].

  20. Selected topics in nuclear structure

    International Nuclear Information System (INIS)

    Solov'ev, V.G.; Gromov, K.Ya.; Malov, L.A.; Shilov, V.M.

    1994-01-01

    The Fourth International Conference on selected topics in nuclear structure was held at Dubna in July 1994 on recent experimental and theoretical investigations in nuclear structure. Topics discussed were the following: nuclear structure at low-energy excitations (collective quasiparticle phenomena, proton-neutron interactions, microscopic and phenomenological theories of nuclear structure; nuclear structure studies with charged particles. heavy ions, neutrons and photons; nuclei at high angular momenta and superdeformation, structure and decay properties of giant resonances, charge-exchange resonances and β-decay; semiclassical approach of large amplitude collective motion and structure of hot nuclei

  1. Diabatic orbitals in nuclear structure

    International Nuclear Information System (INIS)

    Bengtsson, Tord.

    1989-09-01

    The importance of wavefunctions in detailed nuclear structure calculations is emphasized. A scheme to enable studies of the development of wavefunctions as the hamiltonian gradually changes is presented. By using this scheme, nuclear structure properties can be calculated with great detail. (author)

  2. Reconstruction of B hadron decays at DELPHI

    CERN Document Server

    Salmi, Laura Tiina Maria

    2006-01-01

    This thesis describes three analyses related to heavy quarks. The analysis with the largest impact is the extraction of parameters of heavy quark decays using the lepton energy spectrum and the hadronic mass spectrum in semileptonic B decays. The extraction of the parameters allows to test the framework used to theoretically describe the decay of heavy mesons, and more accurate knowledge of the parameter values results in greater accuracy in the determination of the element |Vcb| of the Cabibbo-Kobayashi-Maskawa (CKM) quark mixing matrix. The determination described in this thesis is important, since it is so far the only one where the full lepton energy spectrum has been used. The other determinations are based on using only a part of the spectrum. The first extraction of the parameters in the kinetic mass scheme was based on the statistical moments of the lepton energy spectrum and hadronic mass spectrum measured using the data collected at delphi. In the second analysis, the angular distribution of fragmen...

  3. Weak transitions in the {sup 152}Sm from {sup 152} Eu decay

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Ruy M. [Centro Tecnico Aeroespacial (IEAv/CTA), Sao Jose dos Campos, SP (Brazil). Inst. de Estudos Avancados; Vanin, Vito R.; Pascholati, Paulo R.; Maidana, Nora L. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica

    2010-07-01

    Full text: Few years ago, we reported (R.M. Castro, V.R. Vanin, P.R. Pascholati, N.L. Maidana and M.S. Dias and M.F.Koskinas, Appl. Rad. Isot. 60, 283, 2004) a gamma-gamma coincidence experiment performed to check the gamma-ray transitions following {sup 152}Eu{sup g} 13-year decay and their placement in the decay scheme for metrological purposes. The main results were the observation of weak transitions, in the range 10{sup -4} to 10{sup -5} gamma-rays per decay, and the exclusion of a relatively intense unplaced line from the list of transitions following {sup 152}Eu{sup g} decay. A new paper (W. D. Kulp, J. L. Wood, J. M. Allmond, J. Eimer, D. Furse, K. S. Krane, J. Loats, P. Schmelzenbach, C. J. Stapels, R.-M. Larimer, E. B. Norman, and A. Piechaczek, Phys. Rev. C 76, 034319, 2007), published in 2007, which investigates the {sup 152}Sm nuclear structure, also reported the observation of many weak gamma-ray transitions by coincidence spectroscopy. Despite important differences in the coincidence detector systems, the total number of coincidence events is similar, and the accuracy and the detection threshold are about the same. Thus, all the 27 new transitions reported by Castro et al. in the {sup 152}Sm decay scheme were conformed by Kulp et al. The measured energies form a consistent dataset, with chi-square equal to 38 (8% probability of being exceeded); however, the intensities form a discrepant data set, with chi-square per degree of freedom equal to 3.6, suggesting that the uncertainties are underestimated by a factor of 2. Besides that, Kulp et al. found some transitions not reported previously. So we decided to check our gamma - gamma coincidence spectrum for the presence of these lines. In this new analysis, we did not observe gamma-ray transitions with energies 137.56 and 1050.1 keV, with upper intensity limits well below the intensities given in Kulp et al. The 210.95 keV transition was observed, but with intensity significantly smaller than that

  4. 4. Payment Schemes

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 2. Electronic Commerce - Payment Schemes. V Rajaraman. Series Article Volume 6 Issue 2 February 2001 pp 6-13. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/006/02/0006-0013 ...

  5. Link Monotonic Allocation Schemes

    NARCIS (Netherlands)

    Slikker, M.

    1999-01-01

    A network is a graph where the nodes represent players and the links represent bilateral interaction between the players. A reward game assigns a value to every network on a fixed set of players. An allocation scheme specifies how to distribute the worth of every network among the players. This

  6. Alternative health insurance schemes

    DEFF Research Database (Denmark)

    Keiding, Hans; Hansen, Bodil O.

    2002-01-01

    In this paper, we present a simple model of health insurance with asymmetric information, where we compare two alternative ways of organizing the insurance market. Either as a competitive insurance market, where some risks remain uninsured, or as a compulsory scheme, where however, the level...... competitive insurance; this situation turns out to be at least as good as either of the alternatives...

  7. 4. Payment Schemes

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 2. Electronic Commerce - Payment Schemes. V Rajaraman. Series Article Volume 6 Issue 2 February 2001 pp 6-13 ... Author Affiliations. V Rajaraman1. IBM Professor of Information Technology JNCASR Bangalore 560 064, India.

  8. CSR schemes in agribusiness

    DEFF Research Database (Denmark)

    Pötz, Katharina Anna; Haas, Rainer; Balzarova, Michaela

    2013-01-01

    of schemes that can be categorized on focus areas, scales, mechanisms, origins, types and commitment levels. Research limitations/implications – The findings contribute to conceptual and empirical research on existing models to compare and analyse CSR standards. Sampling technique and depth of analysis limit...

  9. Simple monotonic interpolation scheme

    International Nuclear Information System (INIS)

    Greene, N.M.

    1980-01-01

    A procedure for presenting tabular data, such as are contained in the ENDF/B files, that is simpler, more general, and potentially much more compact than the present schemes used with ENDF/B is presented. The method has been successfully used for Bondarenko interpolation in a module of the AMPX system. 1 figure, 1 table

  10. Nuclear data newsletter. No. 6

    International Nuclear Information System (INIS)

    1984-03-01

    This issue announces the handbook on 'Nuclear Data Standards for Nuclear Measurements', published in the IAEA Technical Reports Series No. 227 (1983) and a meeting on 'Nuclear Standard Reference Data' to be held in November 1984. It lists nuclear data libraries received by the IAEA Nuclear Data Section: EXFOR; INDL/A-83; KEDAK-4; Radioactive decay gammas (GSIGAM-82) and the ENDF/B processing codes. It also lists a selection of new relevant documents

  11. Visible neutrino decay at DUNE

    Energy Technology Data Exchange (ETDEWEB)

    Coloma, Pilar [Fermilab; Peres, Orlando G. [ICTP, Trieste

    2017-05-09

    If the heaviest neutrino mass eigenstate is unstable, its decay modes could include lighter neutrino eigenstates. In this case part of the decay products could be visible, as they would interact at neutrino detectors via mixing. At neutrino oscillation experiments, a characteristic signature of such \\emph{visible neutrino decay} would be an apparent excess of events at low energies. We focus on a simple phenomenological model in which the heaviest neutrino decays as $\

  12. JNDC FP decay data file

    International Nuclear Information System (INIS)

    Yamamoto, Tohru; Akiyama, Masatsugu

    1981-02-01

    The decay data file for fission product nuclides (FP DECAY DATA FILE) has been prepared for summation calculation of the decay heat of fission products. The average energies released in β- and γ-transitions have been calculated with computer code PROFP. The calculated results and necessary information have been arranged in tabular form together with the estimated results for 470 nuclides of which decay data are not available experimentally. (author)

  13. Sum rules for inclusive decays of charmed hadrons

    International Nuclear Information System (INIS)

    Das, T.; Gupta, V.

    1977-01-01

    Inclusive nonleptonic and semileptonic weak decays of the type c → h + anything and c → h + l + + anything are considered, where c is a charmed hadron and h is an ordinary hadron belonging to the 3* and 8 representation of SU(3), respectively. The SU(3) relations for the inclusive decay rates are presented. These would provide tests of the isospin and SU(3) transformation properties of the weak charm-changing current and ΔC = ΔS nonleptonic interaction Hamiltonian in the Glashow-Iliopoulos-Maiani scheme. We also point out that it may be possible to check these relations in the near future

  14. Detailed source term estimation of the atmospheric release for the Fukushima Daiichi Nuclear Power Station accident by coupling simulations of atmospheric dispersion model with improved deposition scheme and oceanic dispersion model

    Science.gov (United States)

    Katata, G.; Chino, M.; Kobayashi, T.; Terada, H.; Ota, M.; Nagai, H.; Kajino, M.; Draxler, R.; Hort, M. C.; Malo, A.; Torii, T.; Sanada, Y.

    2014-06-01

    Temporal variations in the amount of radionuclides released into the atmosphere during the Fukushima Dai-ichi Nuclear Power Station (FNPS1) accident and their atmospheric and marine dispersion are essential to evaluate the environmental impacts and resultant radiological doses to the public. In this paper, we estimate a detailed time trend of atmospheric releases during the accident by combining environmental monitoring data with atmospheric model simulations from WSPEEDI-II (Worldwide version of System for Prediction of Environmental Emergency Dose Information), and simulations from the oceanic dispersion model SEA-GEARN-FDM, both developed by the authors. A sophisticated deposition scheme, which deals with dry and fogwater depositions, cloud condensation nuclei (CCN) activation and subsequent wet scavenging due to mixed-phase cloud microphysics (in-cloud scavenging) for radioactive iodine gas (I2 and CH3I) and other particles (CsI, Cs, and Te), was incorporated into WSPEEDI-II to improve the surface deposition calculations. The fallout to the ocean surface calculated by WSPEEDI-II was used as input data for the SEA-GEARN-FDM calculations. Reverse and inverse source-term estimation methods based on coupling the simulations from both models was adopted using air dose rates and concentrations, and sea surface concentrations. The results revealed that the major releases of radionuclides due to FNPS1 accident occurred in the following periods during March 2011: the afternoon of 12 March due to the wet venting and hydrogen explosion at Unit 1, the morning of 13 March after the venting event at Unit 3, midnight of 14 March when the SRV (Safely Relief Valve) at Unit 2 was opened three times, the morning and night of 15 March, and the morning of 16 March. According to the simulation results, the highest radioactive contamination areas around FNPS1 were created from 15 to 16 March by complicated interactions among rainfall, plume movements, and the temporal variation of

  15. Searching for exotic tau decays

    CERN Document Server

    Alemany, R; González-Garciá, M Concepción; Valle, José W F

    1993-01-01

    We discuss the potential of $\\tau$-charm and B factories for the search of new physics through the study of rare $\\tau$ decays. We consider decays that involve the violation of lepton flavour conservation. Such decays bear a close relationship to the physics of neutrino mass and the properties of the lepton sector of the electroweak theory.

  16. Relativistic pn-QRPA to the double beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Conti, Claudio de [Universidade Estadual Paulista (UNESP), Itapeva, SP (Brazil). Campus Experimental de Itapeva; Krmpotic, F. [Universidad Nacional de La Plata (Argentina). Facultad de Ciencias Astronomicas y Geofisicas; Carlson, Brett Vern [Centro Tecnico Aeroespacial (CTA/ITA), Sao Jose dos Campos, SP (Brazil). Inst. Tecnologico de Aeronautica. Dept. de Fisica

    2010-07-01

    Full text: In nature there are about 50 nuclear systems where the single beta-decay is energetically forbidden, and double- beta decay turns out to be only possible mode of disintegration. It is the nuclear pairing force which causes such an 'anomaly', by making the mass of the odd-odd isobar, (N - 1;Z + 1), to be greater than the masses of its even-even neighbors, (N;Z) and (N - 2;Z +2). The modes by which the double-beta decay can take place are connected with the neutrino and antineutrino distinction. In case the lepton number is strictly conserved the neutrino is a Dirac fermion and the two-neutrino mode is the only possible mode of disintegration. On the other hand, if this conservation is violated, the neutrino is a Majorana particle and neutrinoless double-beta decay also can occur. Both two-neutrino and neutrinoless double-beta decay processes have attracted much attention, because a comparison between experiment and theory for the first, provides a measure of confidence one may have in the nuclear wave function employed for extracting the unknown parameters from neutrinoless lifetime measurements. The proton-neutron (pn) quasiparticle random phase approximation (QRPA) has turned out be the most simple model for calculating the nuclear wave function involved in the double-beta decay transitions. In this work the transition matrix elements for 0{sup +} -> 0{sup +} double-beta decay are calculated for {sup 48}Ca, {sup 76}Ge, {sup 82}Se, {sup 100}Mo, {sup 128}Te and {sup 130}Te nuclei, using a relativistic pn-QRPA based on Hartree-Bogoliubov approximation to the single-particle motion. (author)

  17. Nuclear physics present and future

    CERN Document Server

    2015-01-01

    State-of-the-art survey of topics in nuclear physics by leading practitioners in the field. Major foci are superheavy nuclei and neutron-rich exotic nuclei. In addition new developments in nuclear fission and nuclear cluster decay are shown. Finally developments in relativistic heavy ion collisions and the physics of supercritical fields are detailed.

  18. Decay of 57Ni

    International Nuclear Information System (INIS)

    Santos Scardino, A.M. dos.

    1987-01-01

    The decay of 57 Ni to 57 Co was studied by gamma ray spectroscopy using both singles and coincidence spectra. The sources were obtained with the 58 Ni (Y,n) 57 Ni reaction. Natural metallic nickel was irradiated in the bremsstrahluhng beam of the linear accelerator of the Instituto de Fisica da Universidade de Sao Paulo with 30 MeV electrons. The singles espectra were taken with 104 cc HPGe detector and the coincidences espectra with 27 and 53cc Ge(Li) and 104 cc. HPGe detectors. The energies of transitions that follow the 57 Ni decay were measured using 56 Co as standard (which was obtained by (Y,np) reaction in 58 Ni) and taking into account the cascade cross-over relations. (author) [pt

  19. Electroweak penguin B decays

    CERN Document Server

    Nikodem, Thomas

    2016-01-01

    Flavour Changing Neutral Currents (FCNC) are sensitive probes for physics beyond the Standard Model (SM), so-called New Physics. An example of a FCNC is the $b \\to s$ quark transition described by the electroweak penguin Feynman diagram shown in Figure 1. In the SM such FCNC are only allowed with a loop structure (as e:g: shown in the figure) and not by tree level processes. In the loops heavy particles appear virtually and do not need to be on shell. Therefore also not yet discovered heavy particles with up to a mass $\\mathcal{O}$(TeV) could virtually contribute significantly to observables. Several recent measurements of electroweak penguin B decays exhibit interesting tensions with SM predictions, most prominently in the angular observable $P'_5$ 5 of the decay $B^0 \\to K^{*0} \\mu^+ \\mu^1$[1], which triggered a lot of discussion in the theory community [2]-[14].

  20. Some neutrino decays

    International Nuclear Information System (INIS)

    Levy, J.M.

    1984-01-01

    Massive neutrinos mixing with weak interaction eigenstates are expected to decay into various channels depending on their masses and their mixing pattern. The author reviews some of these decay modes in the simpliest possible frame (νsub(H) → e - e + νsub(e), νsub(n) → γνsub(e), νsub(n) → γγνsub(e) and considers only the addition of right handed neutrino fields to the spectrum of the standard Glashow-Salam-Weinberg theory of weak interactions, thereby allowing for the existence of Dirac masses generated through the coupling of these fields and their left handed mates with the usual Higgs doublet and its charge conjugate, as is the case for quarks

  1. Observation and investigation of the new proton-unbound nuclei {sup 30}Ar and {sup 29}Cl with in-flight decay spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xiaodong

    2016-06-30

    , respectively. The ground state of {sup 30}Ar was found to be 2.45{sup +0.05}{sub -0.10} MeV above the 2p emission threshold. Due to a strong Thomas-Ehrman shift, the lowest states in {sup 30}Ar and {sup 29}Cl point to a violation of isobaric mirror symmetry in the structure of these unbound nuclei. Detailed theoretical calculations of the correlations between 2p decay products followed by the Monte Carlo simulations of the detector response to the 2p decay were performed in order to investigate the decay mechanism of the {sup 30}Ar ground state. Its decay is located in a transition region between simultaneous 2p decay and sequential emission of protons. Such an interplay between the true three-body and the sequential two-body decay mechanisms is the first-time observation in a nuclear ground state. The theoretical investigations of the transition dynamics demonstrated a surprisingly strong sensitivity of the decay correlation patterns to the 2p decay energy of the {sup 30}Ar ground state and the one-proton decay energy as well as the one-proton decay width of the {sup 29}Cl ground state. The first hint on so-called fine structure in the decay of {sup 30}Ar*(2{sup +}) was obtained by detecting two decay branches into both ground state and first excited state of {sup 28}S. The comparison of the experimental {sup 28}S-proton angular correlations with those resulting from the Monte Carlo simulations of the detector response illustrates that other observed {sup 30}Ar excited states decay by sequential emission of protons via intermediate resonances in {sup 29}Cl. The decay schemes of the observed states in {sup 30}Ar and {sup 29}Cl were constructed.

  2. Decay data of the transactinium nuclides

    International Nuclear Information System (INIS)

    1986-01-01

    The report presents the results of the work undertaken from 1978 until 1985 by the participants in the IAEA Co-ordinated Research Programme (CRP) on the Measurement and Evaluation of Transactinium Isotope Nuclear Decay Data. They are given in the form of data tabulations with specific reference to the measurements and evaluations performed by the CRP participants and the data which they recommend for half-lives and branching fractions, gamma ray transition energies and emission probabilities and alpha radiation energies and emission probabilities. A complete set of recommended decay data for heavy nuclei, including data that originate from sources other than the CRP, is given in the last part of the report

  3. Ndos: nuclear data online services

    International Nuclear Information System (INIS)

    Fan, T.S.; Guo, Z.Y.; Ye, W.G.; Liu, W.L.; Feng, Y.Q.; Song, X.X.; Huang, G.; Liu, T.J.; Hong, Y.J.; Liu, C.; Chen, J.X.; Tang, G.Y.; Shi, Z.M.; Huang, X.L.; Chen, J.E.

    2004-01-01

    A Nuclear Data Online Services, Ndos software, has been developed to extract and present nuclear data from various available libraries. Using relational databases the present web-based software offers online data services of a centralized repository of data including eight major international nuclear data libraries for nuclear reaction data, nuclear structure and decay data. A data plotting software package, NDVS (Nuclear Data Viewing Software), which is included in NDOS, facilitates the visualization and manipulation of nuclear data. The NDOS is developed on the Linux implementation of PHP and the MySQL software. The relational nuclear databases and data services are platform independent in a wide sense

  4. Statistical and direct decay of high-lying single-particle excitations

    International Nuclear Information System (INIS)

    Gales, S.

    1993-01-01

    Transfer reactions induced by hadronic probes at intermediate energies have revealed a rich spectrum of high-lying excitations embedded in the nuclear continuum. The investigation of their decay properties is believed to be a severe test of their microscopic structure as predicted by microscopic nuclear models. In addition the degree of damping of these simple modes in the nuclear continuum can be obtained by means of the measured particle (n,p) decay branching ratios. The neutron and proton decay studies of high-lying single-particle states in heavy nuclei are presented. (author). 13 refs., 9 figs

  5. MULTIFLUID MAGNETOHYDRODYNAMIC TURBULENT DECAY

    International Nuclear Information System (INIS)

    Downes, T. P.; O'Sullivan, S.

    2011-01-01

    It is generally believed that turbulence has a significant impact on the dynamics and evolution of molecular clouds and the star formation that occurs within them. Non-ideal magnetohydrodynamic (MHD) effects are known to influence the nature of this turbulence. We present the results of a suite of 512 3 resolution simulations of the decay of initially super-Alfvenic and supersonic fully multifluid MHD turbulence. We find that ambipolar diffusion increases the rate of decay of the turbulence while the Hall effect has virtually no impact. The decay of the kinetic energy can be fitted as a power law in time and the exponent is found to be -1.34 for fully multifluid MHD turbulence. The power spectra of density, velocity, and magnetic field are all steepened significantly by the inclusion of non-ideal terms. The dominant reason for this steepening is ambipolar diffusion with the Hall effect again playing a minimal role except at short length scales where it creates extra structure in the magnetic field. Interestingly we find that, at least at these resolutions, the majority of the physics of multifluid turbulence can be captured by simply introducing fixed (in time and space) resistive terms into the induction equation without the need for a full multifluid MHD treatment. The velocity dispersion is also examined and, in common with previously published results, it is found not to be power law in nature.

  6. Use of systematics in the interpretation of nuclear structure far from the beta-stable region

    International Nuclear Information System (INIS)

    Wood, J.L.

    1979-01-01

    The use of systematics in the interpretation of nuclear structure far from the beta-stable region is discussed. In particular, a set of rules for the use of systematics is presented together with some experimental criteria that need to be fulfilled for radioactive decay scheme studies in order that all states up to a given spin-parity and energy are located. Illustrative examples are taken from the region 180 < A < 210, with particular emphasis on the odd-mass Au and Hg nuclei. 6 figures

  7. Modeling Radionuclide Decay Chain Migration Using HYDROGEOCHEM

    Science.gov (United States)

    Lin, T. C.; Tsai, C. H.; Lai, K. H.; Chen, J. S.

    2014-12-01

    Nuclear technology has been employed for energy production for several decades. Although people receive many benefits from nuclear energy, there are inevitably environmental pollutions as well as human health threats posed by the radioactive materials releases from nuclear waste disposed in geological repositories or accidental releases of radionuclides from nuclear facilities. Theoretical studies have been undertaken to understand the transport of radionuclides in subsurface environments because that the radionuclide transport in groundwater is one of the main pathway in exposure scenarios for the intake of radionuclides. The radionuclide transport in groundwater can be predicted using analytical solution as well as numerical models. In this study, we simulate the transport of the radionuclide decay chain using HYDROGEOCHEM. The simulated results are verified against the analytical solution available in the literature. Excellent agreements between the numerical simulation and the analytical are observed for a wide spectrum of concentration. HYDROGECHEM is a useful tool assessing the ecological and environmental impact of the accidental radionuclide releases such as the Fukushima nuclear disaster where multiple radionuclides leaked through the reactor, subsequently contaminating the local groundwater and ocean seawater in the vicinity of the nuclear plant.

  8. Study of {sup 193}Os beta{sup -} decay; Estudo do decaimento beta{sup -} do {sup 193}Os

    Energy Technology Data Exchange (ETDEWEB)

    Zahn, Guilherme Soares

    2006-07-01

    In this work, the excited levels of {sup 193}Ir populated by the beta{sup -} decay of {sup 193}Os (T{sub 1/2} {approx} 30h) were investigated. For that purpose, {approx} 5 mg samples of 99%-enriched {sup 192}Os were irradiated under a thermal neutron flux of {approx} 10{sup 12} s{sup -1} and then analysed both using single gamma spectroscopy and a 4-detector multi parametric acquisition facility, which provided data for both a gamma gamma coincidence analysis and a directional angular correlation gamma gamma ({theta} ) study. From these data, 28 transitions were added to this decay scheme, 11 of which were previously known from nuclear reactions and 17 observed for the first time. Eight excited levels were also added to the decay scheme, 3 of which were known from nuclear reaction studies - the remaining 5 are suggested for the first time. Moreover, it was possible to confirm suspicions found in reference that the levels at 848.93 keV and 849.093 keV are indeed the same; it was also possible to confirm the existence of an excited level at 806.9 keV, which had been inferred, but not experimentally confirmed in beta decay studies to date. The angular correlation analysis allowed for the definition of the spin of the excited level at 874 keV as 5/2{sup +;} moreover, the results showed a 79% probability that the spin of the 1078 keV level is 5/2/'-, and also restricted the spin possibilities for the new excited level at 960 keV to two values (1/2 or 3/2). It was also possible to measure the multipolarity mixing ratio ({delta}{sub Ln+1}/L{sub n}) for 43 transitions - 19 of them for the first time and most of the others with a better precision than previously known. Finally, an attempt was made to understand the low-lying levels structure for this nucleus using a theoretical model, which reproduced the ground state and the two lowest-lying excited levels in {sup 193}Ir. (author)

  9. Nuclear power plant V-1, V-2

    International Nuclear Information System (INIS)

    2000-01-01

    In this leaflet the principal scheme of the Bohunice V-1 and V-2 nuclear power plants is presented. Thermal scheme of WWER 440-type NPP (primary circuit, secondary circuit, and cooling water circuit) is described

  10. HAGRID/ VANDLE spectroscopy of Rb decays

    Science.gov (United States)

    King, Thomas; Grzywacz, Robert; Taylor, Steven; Paulauskas, Stanley; Smith, Karl; Vandle Collaboration

    2017-09-01

    Many neutron-rich isotopes that contribute in both decay heat production and r-process nucleosynthesis have substantial beta-delayed neutron branching ratios. Beta-delayed neutron emission is a relatively complicated mechanism which can leave the daughter in an gamma-emitting excited state. A comprehensive understanding of their energy output and decay strength, S_beta, therefore requires the detection of both neutrons and gamma rays in coincidence. A series of measurements of delayed neutron precursors were performed at the On-Line Test Facility (OLTF) at the Oak Ridge National Laboratories using chemically selective ion sources and an enhanced VANDLE array. The main goal of this experiment was to revisit the decays of IAEA-marked priority precursors, including bromine, rubidium, cesium, and iodine, that are required to model the global properties in the fission of 238U.The unique data set, with neutron and gamma ray coincidences, benefited from the addition of a high-efficiency gamma-ray array, consisting of 16 LaBr3 crystals (HAGRiD), and a set of large volume NaI detectors to the VANDLE array. Characterization of and preliminary results from the new gamma-ray array for the decays of 94Rb and 97Rb will be presented. National Nuclear Security Administration under the Stewardship Science Academic Alliances program through DOE Award No. DE-NA0002132 and the Office of Nuclear Physics, U.S. Department of Energy under Award No. DE-FG02-96ER40983.

  11. The development of the nuclear physics in Latvia

    International Nuclear Information System (INIS)

    Ulmanis, U.

    2003-01-01

    The history of the nuclear physics (NP) in Latvia begun in the 50-ies of the past century and is associated with the Institute of Physics (IP) Latvian Academy of Science. The plan of 1952 has contained theoretical works about interaction of elementary particles (P.Kunin and I.Taksar), the use of radioactive isotopes as 'labelled atoms' in industry (the marketing of steel tapes) and other topics. During 1952-1955 in the IP as the leader of NP works has been Arshavir Karamyan, scientific worker of D.Mendeleev All-Union Research Institute of Metrology in St.Petersburg (then Leningrad). He has been also scientific supervisors of the IP scientist Peteris Prokofjevs post-graduate studies in St.Petersburg on 1952-1956. The theme of this thesis was related with the construction of magnetic gamma-spectrometer. During the period 195-1957 the practical use of radioisotopes as labelled atoms and sources of ionising radiation has been developed in laboratory of radioactive methods in automation (leader V.Janushkovskii). At that time different apparatus with radioisotopes for counting of things, regulation of temperature, current, voltage, measure of different liquid levels etc. have been well known in the world (exhibitions, international conferences). The other, isotope laboratory (leader J.Chudars) was connected with research in nuclear spectroscopy and interaction of radiation with matter problems: construction of gamma- and beta spectrometers, gamma-gamma and gamma-beta coincidence schemes, measure of decay schemes of different radioisotopes (L. Pelekis, J.Chudars, I.Taure, L.Bambe) measure of periods of half-decay (V.Breslav) and the gamma-ray scattering in materials (U.Ulmanis and N.Dubinska). The next stage of the development of nuclear physics in Latvia is connected with the research nuclear reactor in Salaspils. (author)

  12. Charmless b decays at CDF

    Energy Technology Data Exchange (ETDEWEB)

    Donega, Mauro; /Geneva U.

    2005-07-01

    The authors report on the charmless B decays measurements performed on 180 pb{sup -1} of data collected with the CDF II detector at the Fermilab Tevatron collider. This paper describes: the first observation of the decay mode B{sub s} {yields} K{sup +}K{sup -} and the measurement of the direct Cp asymmetry in the ({bar B}){sub d} {yields} K{sup {+-}}{pi}{sup {-+}} decay; the first evidence of the decay mode B{sub s} {yields} {phi}{phi} and the branching ratio and Cp asymmetry for the B{sup {+-}} {yields} {phi}K{sup {+-}} decay.

  13. Nuclear data services of the Nuclear Data Centers Network available at the National Nuclear Data Center

    International Nuclear Information System (INIS)

    McLane, V.

    1997-01-01

    The Nuclear Data Centers Network provides low and medium energy nuclear reaction data to users around the world. Online retrievals are available through the U.S. National Nuclear Data Center, the Nuclear Energy Agency Data Bank, and the IAEA Nuclear Data Section from these extensive bibliographic, experimental data, and evaluated data files. In addition to nuclear reaction data, the various databases also provide nuclear structure and decay data, and other information of interest to users. The WorldWideWeb sites at the National Nuclear Data Center and the NEA Data Bank provide access to some of the Centers' files. (orig.)

  14. On Converting Secret Sharing Scheme to Visual Secret Sharing Scheme

    Directory of Open Access Journals (Sweden)

    Wang Daoshun

    2010-01-01

    Full Text Available Abstract Traditional Secret Sharing (SS schemes reconstruct secret exactly the same as the original one but involve complex computation. Visual Secret Sharing (VSS schemes decode the secret without computation, but each share is m times as big as the original and the quality of the reconstructed secret image is reduced. Probabilistic visual secret sharing (Prob.VSS schemes for a binary image use only one subpixel to share the secret image; however the probability of white pixels in a white area is higher than that in a black area in the reconstructed secret image. SS schemes, VSS schemes, and Prob. VSS schemes have various construction methods and advantages. This paper first presents an approach to convert (transform a -SS scheme to a -VSS scheme for greyscale images. The generation of the shadow images (shares is based on Boolean XOR operation. The secret image can be reconstructed directly by performing Boolean OR operation, as in most conventional VSS schemes. Its pixel expansion is significantly smaller than that of VSS schemes. The quality of the reconstructed images, measured by average contrast, is the same as VSS schemes. Then a novel matrix-concatenation approach is used to extend the greyscale -SS scheme to a more general case of greyscale -VSS scheme.

  15. Decays of 116Sb isomers to levels in 116Sn

    International Nuclear Information System (INIS)

    Gacsi, Z.; Raman, S.

    1994-01-01

    The excited states of 116 Sn were studied by means of the decays of the 15.8-min, 3 + 116 Sb ground state, and the 60.3-min, 8 - 116 Sb isomer. Over 50 γ rays were observed; these were incorporated into a level scheme consisting of 32 excited states. Except for one new level proposed at 3.986 MeV, the current study fully supports an exhaustive study of levels in 116 Sn reported earlier. The previous study was an attempt to develop a nearly ''complete'' level scheme of 116 Sn up to an excitation energy of 4.3 MeV

  16. Unexpected high-energy γ emission from decaying exotic nuclei

    Directory of Open Access Journals (Sweden)

    A. Gottardo

    2017-09-01

    Full Text Available The N=52 Ga83 β decay was studied at ALTO. The radioactive 83Ga beam was produced through the ISOL photofission technique and collected on a movable tape for the measurement of γ-ray emission following β decay. While β-delayed neutron emission has been measured to be 56–85% of the decay path, in this experiment an unexpected high-energy 5–9 MeV γ-ray yield of 16(4% was observed, coming from states several MeVs above the neutron separation threshold. This result is compared with cutting-edge QRPA calculations, which show that when neutrons deeply bound in the core of the nucleus decay into protons via a Gamow–Teller transition, they give rise to a dipolar oscillation of nuclear matter in the nucleus. This leads to large electromagnetic transition probabilities which can compete with neutron emission, thus affecting the β-decay path. This process is enhanced by an excess of neutrons on the nuclear surface and may thus be a common feature for very neutron-rich isotopes, challenging the present understanding of decay properties of exotic nuclei.

  17. Double beta decay in gauge theories

    International Nuclear Information System (INIS)

    Vergados, J.D.

    2002-01-01

    Neutrinoless double beta decay is a very important process both from the particle and nuclear physics point of view. From the elementary particle point of view it pops up in almost every model, giving rise among others to the following mechanisms: a) The traditional contributions like the light neutrino mass mechanism as well as the j L - j R leptonic interference (λ and η terms). b) The exotic R-parity violating supersymmetric (SUSY) contributions. From the nuclear physics point of view it is challenging, because: 1) The nuclei, which can undergo double beta decay, have complicated nuclear structure. 2) The energetically allowed transitions are suppressed (exhaust a small part of all the strength). 3) Since in some mechanisms the intermediate particles are very heavy one must cope with the short distance behavior of the transition operators. 4) The intermediate momenta involved are quite high and one has to consider momentum dependent terms of the nucleon current. Taking the above effects into account from the experimental limits on the interesting nuclei A=76, 82, 96, 100, 116, 128, 130, 136 and 150, we have extracted new limits on the various lepton violating parameters. In particular we get a stringent limit on the R-parity violating parameter λ' 111 -4 . (author)

  18. Nuclear Data Sheets for A = 26

    Energy Technology Data Exchange (ETDEWEB)

    Basunia, M.S.; Hurst, A.M.

    2016-05-15

    Evaluated spectroscopic data and level schemes from radioactive decay and nuclear reaction studies are presented for {sup 26}O, {sup 26}F, {sup 26}Ne, {sup 26}Na, {sup 26}Mg, {sup 26}Al, {sup 26}Si, {sup 26}P, and {sup 26}S. This evaluation for A = 26 supersedes the earlier one by P. M. Endt (1998En04) and updates for some nuclides in ENSDF. Highlights of this evaluation are the following: This evaluation includes search results for {sup 26}S nuclide and its proton–decay mode (2011Fo08). An isomeric state (2.2 ms) in {sup 26}F has been discovered by 2013Le03. The state is proposed at 643.4 keV 1 from γ–ray measurements. Internal-transition and beta-decay branches for the state are also determined. New excited levels in {sup 26}Ne have been identified from {sup 26}F β{sup −} decay (2.2 ms). For some {sup 26}Si resonance states conflicting spin-parity assignments exist in the literature. These are identified by footnotes. 2015Do07 ({sup 3}He,nγ) propose the first 0+ state above proton separation energy at an excitation energy of 5890 keV and suggested for additional independent measurements to confirm or refute the existence of 5946 keV 4. 2016Ch09 consider 5946 keV level as a distinct excited state in their reanalysis of the literature data with possible spin-parity assignment of 0+ or 4+ This evaluation also includes discovery of an isomeric state, at 164.1 keV 1, in {sup 26}P by 2014NiZZ.

  19. Nuclear Data Sheets for A = 26

    Science.gov (United States)

    Basunia, M. S.; Hurst, A. M.

    2016-05-01

    Evaluated spectroscopic data and level schemes from radioactive decay and nuclear reaction studies are presented for 26O, 26F, 26Ne, 26Na, 26Mg, 26Al, 26Si, 26P, and 26S. This evaluation for A = 26 supersedes the earlier one by P. M. Endt (1998En04) and updates for some nuclides in ENSDF. Highlights of this evaluation are the following: This evaluation includes search results for 26S nuclide and its proton-decay mode (2011Fo08). An isomeric state (2.2 ms) in 26F has been discovered by 2013Le03. The state is proposed at 643.4 keV 1 from γ-ray measurements. Internal-transition and beta-decay branches for the state are also determined. New excited levels in 26Ne have been identified from 26F β- decay (2.2 ms). For some 26Si resonance states conflicting spin-parity assignments exist in the literature. These are identified by footnotes. 2015Do07 (3He,nγ) propose the first 0+ state above proton separation energy at an excitation energy of 5890 keV and suggested for additional independent measurements to confirm or refute the existence of 5946 keV 4. 2016Ch09 consider 5946 keV level as a distinct excited state in their reanalysis of the literature data with possible spin-parity assignment of 0+ or 4+ This evaluation also includes discovery of an isomeric state, at 164.1 keV 1, in 26P by 2014NiZZ.

  20. Proton capture reactions and nuclear structure

    International Nuclear Information System (INIS)

    Kikstra, S.W.

    1989-01-01

    Experimental studies are described of the structure of 40 Ca and 42 Sc with measurements at proton-capture of (p, gamma) reactions. Where possible, an attempt has been made to interpret the results of the measurements in termsof existing models. The 40 Ca and 42 Sc nuclides were excited by bombarding 39 K and 41 Ca targets, respectively with low energy protons (E p = 0.3-3.0 MeV), that were produced by the Utrecht 3MV van de Graaff accelerator. From the measured energy and intensity of the gamma-rays created in the subsequent decay of the cuclei, information was obtained on the existence and properties of their excited states. In addition properties of two T = 3/2 levels at high excitation energy of the 9 Be nucleus were investigated. These levels were excited by the resonant absorption of gamma-rays from the 11 B(p, gamma) 12 C reaction. The results of the measurements are interpreted by a comparison to the analoque β-decay of 9 Li and to shell model calculations. The total decay energy of the superallowed O + → O + transition between the ground states of 42 Sc and 42 Ca was determined by measurements in Utrecht of the proton separation energy S p of 42 Sc and in Oak Ridge of S n of 42 Sc and 42 Ca. The results were used for verification of the conserved vector current hypothesis, which implies that the ft values of all superallowed O + → O + β-decays are the same. An attempt was made to describe properties of odd-parity states of A = 37-41 nuclei with a variant of the Warburton, Becker, Millener and Brown (WBMB) interaction.Finally a new method for the assignment of nuclear spins by a simple statistical analysis of spectroscopic information is proposed. (author). 169 refs.; 22 figs.; 24 schemes; 29 tabs

  1. Rare B decays at LHCb

    CERN Document Server

    Puig Navarro, Albert

    2017-01-01

    Rare decays are flavour changing neutral current processes that allow sensitive searches for phenomena beyond the Standard Model (SM). In the SM, rare decays are loop-suppressed and new particles in SM extensions can give significant contributions. The very rare decay $B^0_s\\to\\mu^+\\mu^-$ in addition helicity suppressed and constitutes a powerful probe for new (pseudo) scalar particles. Of particular interest are furthermore tests of lepton universality in rare $b\\to s\\ell^+\\ell^-$ decays. The LHCb experiment is designed for the study of b-hadron decays and ideally suited for the analysis of rare decays due to its high trigger efficiency, as well as excellent tracking and particle identification performance. Recent results from the LHCb experiment in the area of rare decays are presented, including tests of lepton universality and searches for lepton flavour violation.

  2. Beyond Scheme F

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, C.J.; Fisher, H.; Pepin, J. [Los Alamos National Lab., NM (United States); Gillmann, R. [Federal Highway Administration, Washington, DC (United States)

    1996-07-01

    Traffic classification techniques were evaluated using data from a 1993 investigation of the traffic flow patterns on I-20 in Georgia. First we improved the data by sifting through the data base, checking against the original video for questionable events and removing and/or repairing questionable events. We used this data base to critique the performance quantitatively of a classification method known as Scheme F. As a context for improving the approach, we show in this paper that scheme F can be represented as a McCullogh-Pitts neural network, oar as an equivalent decomposition of the plane. We found that Scheme F, among other things, severely misrepresents the number of vehicles in Class 3 by labeling them as Class 2. After discussing the basic classification problem in terms of what is measured, and what is the desired prediction goal, we set forth desirable characteristics of the classification scheme and describe a recurrent neural network system that partitions the high dimensional space up into bins for each axle separation. the collection of bin numbers, one for each of the axle separations, specifies a region in the axle space called a hyper-bin. All the vehicles counted that have the same set of in numbers are in the same hyper-bin. The probability of the occurrence of a particular class in that hyper- bin is the relative frequency with which that class occurs in that set of bin numbers. This type of algorithm produces classification results that are much more balanced and uniform with respect to Classes 2 and 3 and Class 10. In particular, the cancellation of errors of classification that occurs is for many applications the ideal classification scenario. The neural network results are presented in the form of a primary classification network and a reclassification network, the performance matrices for which are presented.

  3. Nuclear data online

    International Nuclear Information System (INIS)

    McLane, V.

    1997-01-01

    The National Nuclear Data Center (NNDC) Online Data Service, available since 1986, is continually being upgraded and expanded. Most files are now available for access through the World Wide Web. Bibliographic, experimental, and evaluated data files are available containing information no neutron, charged-particle, and photon-induced nuclear reaction data, as well as nuclear decay and nuclear structure information. An effort is being made through the world-wide Nuclear Reaction Data Centers collaboration to make the charged-particle reaction data libraries as complete as possible. The data may be downloaded or viewed both as plots or as tabulated data. A variety of output formats are available for most files

  4. Scalable Nonlinear Compact Schemes

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Debojyoti [Argonne National Lab. (ANL), Argonne, IL (United States); Constantinescu, Emil M. [Univ. of Chicago, IL (United States); Brown, Jed [Univ. of Colorado, Boulder, CO (United States)

    2014-04-01

    In this work, we focus on compact schemes resulting in tridiagonal systems of equations, specifically the fifth-order CRWENO scheme. We propose a scalable implementation of the nonlinear compact schemes by implementing a parallel tridiagonal solver based on the partitioning/substructuring approach. We use an iterative solver for the reduced system of equations; however, we solve this system to machine zero accuracy to ensure that no parallelization errors are introduced. It is possible to achieve machine-zero convergence with few iterations because of the diagonal dominance of the system. The number of iterations is specified a priori instead of a norm-based exit criterion, and collective communications are avoided. The overall algorithm thus involves only point-to-point communication between neighboring processors. Our implementation of the tridiagonal solver differs from and avoids the drawbacks of past efforts in the following ways: it introduces no parallelization-related approximations (multiprocessor solutions are exactly identical to uniprocessor ones), it involves minimal communication, the mathematical complexity is similar to that of the Thomas algorithm on a single processor, and it does not require any communication and computation scheduling.

  5. $\\alpha$-decay study of $^{182,184}$Tl

    CERN Document Server

    Van Beveren, C; Barzakh, A E; Cocolios, T E; de Groote, R P; Fedorov, D; Fedosseev, V N; Ferrer, R; Ghys, L; Huyse, M; Köster, U; Lane, J; Liberati, V; Lynch, K M; Marsh, B A; Molkanov, P L; Procter, T J; Rapisarda, E; Sandhu, K; Seliverstov, M D; Van Duppen, P; Venhart, M; Veselský, M

    2016-01-01

    α -decay spectroscopy of 182,184 Tl has been performed at the CERN isotope separator on-line ( ISOLDE ) facility. New fi ne-structure α decays have been observed for both isotopes. α -decay branching ratios of 0.089 ( 19 ) %, 0.047 ( 6 ) % and 1.22 ( 30 ) % have been deduced for the ( 10 − ) , ( 7 + ) and ( 2 − ) states respectively in 184 Tl and a lower limit of 0.49% for the α -decay branching ratio of 182 Tl. A new half-life of 9.5 ( 2 ) s for the ( 2 − ) state in 184 Tl and 1.9 ( 1 ) s for the low-spin state in 182 Tl has been deduced. Using α – γ coincidence analysis, multiple γ rays were observed de-exciting levels in 178,18 0 Au fed by 182,184 Tl α decays. The γ transitions connecting these low-lying states in 178,18 0 Au are essential to sort the data and possibly identify bands from in- beam studies in these isotopes. Owing to the complex fi ne-structure α decays and limited knowledge about the structure of the daughter nuclei, only partial level schemes could be constructed for bot...

  6. Quantum identification schemes with entanglements

    International Nuclear Information System (INIS)

    Mihara, Takashi

    2002-01-01

    We need secure identification schemes because many situations exist in which a person must be identified. In this paper, we propose three quantum identification schemes with entanglements. First, we propose a quantum one-time pad password scheme. In this scheme, entanglements play the role of a one-time pad password. Next, we propose a quantum identification scheme that requires a trusted authority. Finally, we propose a quantum message authentication scheme that is constructed by combining a different quantum cryptosystem with an ordinary authentication tag

  7. Nuclear astrophysics

    Science.gov (United States)

    Penionzhkevich, Yu. E.

    2010-08-01

    The International Year of Astronomy 2009 (IYA2009) was declared by the 62nd General Assembly of the United Nations and was also endorsed by UNESCO. Investigations in the realms of particle and nuclear physicsmake a large contribution in the development of our ideas of the properties of the Universe. The present article discusses some problems of the evolution of the Universe, nucleosyntheses, and cosmochronology from the point of view of nuclear and particle physics. Processes occurring in the Universe are compared with the mechanisms of the production and decay of nuclei, as well as with the mechanisms of their interaction at high energies. Examples that demonstrate the potential of nuclearphysics methods for studying cosmic objects and the properties of the Universe are given. The results that come from investigations into nuclear reactions induced by beams of radioactive nuclei and which make it possible to take a fresh look at the nucleosynthesis scenario in the range at light nuclei are presented.

  8. Unstable decay and state selection

    International Nuclear Information System (INIS)

    McKane, Alan; Tarlie, Martin

    2001-01-01

    The decay of unstable states when several metastable states are available for occupation is investigated using path-integral techniques. Specifically, a method is described that enables the probabilities with which the metastable states are occupied to be calculated by finding optimal paths, and fluctuations about them, in the weak-noise limit. The method is illustrated on a system described by two coupled Langevin equations, which are found in the study of instabilities in fluid dynamics and superconductivity. The problem involves a subtle interplay between nonlinearities and noise, and a naive approximation scheme that does not take this into account is shown to be unsatisfactory. The use of optimal paths is briefly reviewed and then applied to finding the conditional probability of ending up in one of the metastable states, having begun in the unstable state. There are several aspects of the calculation that distinguish it from most others involving optimal paths: (i) the paths do not begin and end on an attractor, and moreover, the final point is to a large extent arbitrary, (ii) the interplay between the fluctuations and the leading-order contribution are at the heart of the method, and (iii) the final result involves quantities that are not exponentially small in the noise strength. This final result, which gives the probability of a particular state being selected in terms of the parameters of the dynamics, is remarkably simple and agrees well with the results of numerical simulations. The method should be applicable to similar problems in a number of other areas, such as state selection in lasers, activationless chemical reactions, and population dynamics in fluctuating environments

  9. NUCLEAR DATA RESOURCES FOR ADVANCED ANALYSIS AND SIMULATION.

    Energy Technology Data Exchange (ETDEWEB)

    PRITYCHENKO, B.

    2006-06-05

    The mission of the National Nuclear Data Center (NNDC) includes collection, evaluation, and dissemination of nuclear physics data for basic nuclear research and applied nuclear technologies. In 2004, to answer the needs of nuclear data users, NNDC completed a project to modernize storage and management of its databases and began offering new nuclear data Web services. Examples of nuclear reaction, nuclear structure and decay database applications along with a number of nuclear science codes are also presented.

  10. Radioactive decay data tables: A handbook of decay data for application to radiation dosimetry and radiological assessments

    Science.gov (United States)

    Kocher, D. C.; Smith, J. S.

    Decay data are presented for approximately 500 radionuclides including those occurring naturally in the environment, those of potential importance in routine or accidental releases from the nuclear fuel cycle, those of current interest in nuclear medicine and fusion reactor technology, and some of those of interest to Committee 2 of the International Commission on Radiological Protection for the estimation of annual limits on intake via inhalation and ingestion for occupationally exposed individuals. Physical processes involved in radioactive decay which produce the different types of radiation observed, methods used to prepare the decay data sets for each radionuclide in the format of the computerized evaluated nuclear structure data file, the tables of radioactive decay data, and the computer code MEDLIST used to produce the tables are described. Applications of the data to problems of interest in radiation dosimetry and radiological assessments are considered as well as the calculations of the activity of a daughter radionuclide relative to the activity of its parent in a radioactive decay chain.

  11. An application program for fission product decay heat calculations

    International Nuclear Information System (INIS)

    Pham, Ngoc Son; Katakura, Jun-ichi

    2007-10-01

    The precise knowledge of decay heat is one of the most important factors in safety design and operation of nuclear power facilities. Furthermore, decay heat data also play an important role in design of fuel discharges, fuel storage and transport flasks, and in spent fuel management and processing. In this study, a new application program, called DHP (Decay Heat Power program), has been developed for exact decay heat summation calculations, uncertainty analysis, and for determination of the individual contribution of each fission product. The analytical methods were applied in the program without any simplification or approximation, in which all of linear and non-linear decay chains, and 12 decay modes, including ground state and meta-stable states, are automatically identified, and processed by using a decay data library and a fission yield data file, both in ENDF/B-VI format. The window interface of the program is designed with optional properties which is very easy for users to run the code. (author)

  12. Decay properties of some neutron-rich praseodymium isotopes

    International Nuclear Information System (INIS)

    Skarnemark, G.; Aronsson, P.O.; Stender, E.; Trautmann, N.; Kaffrell, N.; Bjoernstad, T.; Kvale, E.; Skarestad, M.

    1976-01-01

    Neutron-rich Pr isotopes produced in the thermal neutron-induced fission of 235 U have been investigated by means of γ-γ coincidence experiments. The nuclides have been separated from the fission product mixture, using the fast chemical separation system SISAK in connection with a gas jet recoil transport system. The results include assignments of several new γ-ray energies and partial decay schemes for 147 Pr, 148 Pr, 149 Pr and 150 Pr. (orig.) [de

  13. b → s+H0 decay in sypersymmetric theories

    International Nuclear Information System (INIS)

    Iogansen, A.A.; Ural'tsev, N.G.; Khoze, V.A.

    1989-01-01

    The H 0 production probability in decays of B mesons is calculated in the framework of the supersymmetric models which naturally allow the existence of the light H 0 boson. The quantity Br(b→s+H) is shown to be strongly suppressed compared to the standard model prediction. The major compensation of the standard contribution comes from the H ± -boson exchange. The Higgsino-vino role is less important. Contributions from neutral superparticles including gluino turn out to be negligible. Due to the smallness of the b→s+H 0 amplitude, the available experimental data on B meson decays cannot exclude the existence of the light H 0 boson of supersymmetric schemes. At the same time, the probabilities of radiative decays of quarkonia like Υ → H 0 +γ remain the same as in the standard model

  14. Cluster decay analysis and related structure effects of fissionable ...

    Indian Academy of Sciences (India)

    2015-08-01

    Aug 1, 2015 ... formed under extreme conditions of temperature, angular momentum, etc., exhibit differ- ent decay mechanisms which are helpful in providing furtherance to understand numerous nuclear properties and associated dynamical aspects. It has been observed that depending on its mass (ACN), the equilibrated ...

  15. Nuclear Data Section status report

    International Nuclear Information System (INIS)

    Muir, D.; Pronyaev, V.G.

    2001-01-01

    This report summarises the Nuclear Structure and Decay Data (NSDD) related activity of the IAEA Nuclear Data Section (NDS) for the period October 1998 to September 2000. It covers both online NSDD user service either Telnet or Web services, and offline NSDD service. The NSDD development programs and projects are related to NDS contribution to the IAEA Analytical Quality Control Services program, Coordinated Research Project on nuclear model parameter testing for nuclear data evaluation, Coordinated Research Project on updating of x-ray and gamma-ray decay data standards for detector calibration, and Coordinated Research Project on development of database for prompt gamma-neutron activation analysis

  16. Theory of neutrinoless double beta decay

    CERN Document Server

    Vergados, J.D.; Simkovic, F.

    2012-01-01

    Neutrinoless double beta decay, which is a very old and yet elusive process, is reviewed. Its observation will signal that lepton number is not conserved and the neutrinos are Majorana particles. More importantly it is our best hope for determining the absolute neutrino mass scale at the level of a few tens of meV. To achieve the last goal certain hurdles have to be overcome involving particle, nuclear and experimental physics. Nuclear physics is important for extracting the useful information from the data. One must accurately evaluate the relevant nuclear matrix elements, a formidable task. To this end, we review the sophisticated nuclear structure approaches recently been developed, which give confidence that the needed nuclear matrix elements can be reliably calculated. From an experimental point of view it is challenging, since the life times are long and one has to fight against formidable backgrounds. If a signal is found, it will be a tremendous accomplishment. Then, of course, the real task is going ...

  17. Beta decay and magnetic moments as tools to probe nuclear structure. Study of neutron-rich nuclei around N=40; Decroissance beta et moments magnetiques comme outils pour sonder la structure nucleaire. Etude des noyaux riches en neutrons autour de N=40

    Energy Technology Data Exchange (ETDEWEB)

    Matea, I

    2003-12-01

    The evolution of nuclear structure in nuclei far from the {beta} stability line is one of the 'hot topics' in modern experimental and theoretical nuclear physics. The present thesis is devoted to the study of structure of neutron-rich nuclei around N=40. The evolution of the neutron g9/2 orbital with increasing number of neutrons is one of the key points defining the structure of these nuclei at low excitation energy. We used for this investigation as experimental tools the magnetic dipole moments measurements and the {beta} decay spectroscopy. For the measurement of the gyromagnetic factor of the 9/2{sup +} isomeric state in Fe{sup 61} we have applied the TDPAD method. This method (like most of measurements of nuclear moments) requires an oriented ensemble of nuclei. The orientation of Fe{sup 61m} was achieved via the fragmentation of Ni{sup 64} at 55 MeV/u and the selection of the fragment momentum with the LISE spectrometer at GANIL. The experimental device was specially conceived to preserve the alignment up to the implantation point. The measured value of the g factor was compared with large-scale shell model and Hartree-Fock-Bogoliubov model predictions. The nuclei studied via {beta} decay were produced by the fragmentation of Kr{sup 86} at 58 MeV/u. For the selection of reaction products we used for the first time the LISE2000 spectrometer and for the detection of {gamma} rays four EXOGAM clover detectors. We measured 5 new lifetimes and 4 lifetimes with a higher precision. From the prompt {beta}{gamma} coincidences we identified new states in the daughter nuclei, as it is the case of the first 2{sup +} excited states in Fe{sup 68} and Ni{sup 72}. The results were compared with the predictions of the large-scale shell model. Other transitions were observed for the first time in {beta}{gamma} decay of Ti{sup 60}, Fe{sup 70} and Co{sup 71,73}. (author)

  18. ESCAP mobile training scheme.

    Science.gov (United States)

    Yasas, F M

    1977-01-01

    In response to a United Nations resolution, the Mobile Training Scheme (MTS) was set up to provide training to the trainers of national cadres engaged in frontline and supervisory tasks in social welfare and rural development. The training is innovative in its being based on an analysis of field realities. The MTS team consisted of a leader, an expert on teaching methods and materials, and an expert on action research and evaluation. The country's trainers from different departments were sent to villages to work for a short period and to report their problems in fulfilling their roles. From these grass roots experiences, they made an analysis of the job, determining what knowledge, attitude and skills it required. Analysis of daily incidents and problems were used to produce indigenous teaching materials drawn from actual field practice. How to consider the problems encountered through government structures for policy making and decisions was also learned. Tasks of the students were to identify the skills needed for role performance by job analysis, daily diaries and project histories; to analyze the particular community by village profiles; to produce indigenous teaching materials; and to practice the role skills by actual role performance. The MTS scheme was tried in Nepal in 1974-75; 3 training programs trained 25 trainers and 51 frontline workers; indigenous teaching materials were created; technical papers written; and consultations were provided. In Afghanistan the scheme was used in 1975-76; 45 participants completed the training; seminars were held; and an ongoing Council was created. It is hoped that the training program will be expanded to other countries.

  19. Bonus Schemes and Trading Activity

    NARCIS (Netherlands)

    Pikulina, E.S.; Renneboog, L.D.R.; Ter Horst, J.R.; Tobler, P.N.

    2013-01-01

    Abstract: Little is known about how different bonus schemes affect traders’ propensity to trade and which bonus schemes improve traders’ performance. We study the effects of linear versus threshold (convex) bonus schemes on traders’ behavior. Traders purchase and sell shares in an experimental stock

  20. Scheme of stepmotor control

    International Nuclear Information System (INIS)

    Grashilin, V.A.; Karyshev, Yu.Ya.

    1982-01-01

    A 6-cycle scheme of step motor is described. The block-diagram and the basic circuit of the step motor control are presented. The step motor control comprises a pulse shaper, electronic commutator and power amplifiers. The step motor supply from 6-cycle electronic commutator provides for higher reliability and accuracy than from 3-cycle commutator. The control of step motor work is realised by the program given by the external source of control signals. Time-dependent diagrams for step motor control are presented. The specifications of the step-motor is given

  1. Generalization of the event-based Carnevale-Hines integration scheme for integrate-and-fire models

    NARCIS (Netherlands)

    van Elburg, R.A.J.; van Ooyen, A.

    2009-01-01

    An event-based integration scheme for an integrate-and-fire neuron model with exponentially decaying excitatory synaptic currents and double exponential inhibitory synaptic currents has been introduced by Carnevale and Hines. However, the integration scheme imposes nonphysiological constraints on

  2. Nuclear data and related services

    International Nuclear Information System (INIS)

    Tuli, J.K.

    1985-01-01

    National Nuclear Data Center (NNDC) maintains a number of data bases containing bibliographic information and evaluated as well as experimental nuclear properties. An evaluated computer file maintained by the NNDC, called the Evaluated Nuclear Structure Data File (ENSDF), contains nuclear structure information for all known nuclides. The ENSDF is the source for the journal Nuclear Data Sheets which is produced and edited by NNDC. The Evaluated Nuclear Data File (ENDF), on the other hand is designed for storage and retrieval of such evaluated nuclear data as are used in neutronic, photonic, and decay heat calculations in a large variety of applications. The NNDC maintains three bibliographic files: NSR - for nuclear structure and decay data related references, CINDA - a bibliographic file for neutron induced reactions, and CPBIB - for charged particle reactions. Selected retrievals from evaluated data and bibliographic files are possible on-line or on request from NNDC

  3. Rare beauty and charm decays

    Science.gov (United States)

    Blake, T.; LHCb Collaboration

    2017-07-01

    Rare beauty and charm decays can provide powerful probes of physics beyond the Standard Model. These proceedings summarise the latest measurements of rare beauty and charm decays from the LHCb experiment at the end of Run 1 of the LHC. Whilst the majority of the measurements are consistent with SM predictions, small differences are seen in the rate and angular distribution of ℓ- decay processes.

  4. Decay and fission of the oriented nuclei

    CERN Document Server

    Kadmenskij, S G

    2002-01-01

    The fragment angular distributions for binary decay of oriented spherical and deformed nuclei with taking into account the correct transformational properties of wave functions under time inversion have been investigated. It has been shown that for description of fragment angular distributions the adiabatic approximation for collective rotational nuclear degrees of freedom is not correct. It has been demonstrated that this approximation is valid for description of spontaneous and induced low-energy nuclear fission. The dependence of partial fission widths on the orientation of the internal axes spins, projections of spins, and relative angular moments of fission fragments has been analyzed. It has been shown that the adiabatic approximation results in coherent interference of wave functions of fragments relative movement. This interference forms fragments the universal angular distributions of fission fragments for oriented nuclei. For these distributions the deviations from A. Bohr's formula have been invest...

  5. Weak decays of heavy quarks

    International Nuclear Information System (INIS)

    Gaillard, M.K.

    1978-08-01

    The properties that may help to identify the two additional quark flavors that are expected to be discovered. These properties are lifetime, branching ratios, selection rules, and lepton decay spectra. It is also noted that CP violation may manifest itself more strongly in heavy particle decays than elsewhere providing a new probe of its origin. The theoretical progress in the understanding of nonleptonic transitions among lighter quarks, nonleptonic K and hyperon decay amplitudes, omega minus and charmed particle decay predictions, and lastly the Kobayashi--Maskawa model for the weak coupling of heavy quarks together with the details of its implications for topology and bottomology are treated. 48 references

  6. Charm meson decays at CESR

    International Nuclear Information System (INIS)

    Yamamoto, H.

    1994-01-01

    The author discusses a number of different topics. First is the question of where CESR will be in the year 2000, in terms of luminosity and its detector, and the impact of this on charm physics. Also what has been learned of semileptonic decays of D 0 , D + , D s , and Cabbibo-favored/suppressed decays. Studies of hadronic decays, Cabbibo-favored/suppressed, rare decays, mixing, and CP invariance. What role can a Tau Charm Factory play in this type of physics, and what can it tell us beyond what we can reach at present

  7. Packet reversed packet combining scheme

    International Nuclear Information System (INIS)

    Bhunia, C.T.

    2006-07-01

    The packet combining scheme is a well defined simple error correction scheme with erroneous copies at the receiver. It offers higher throughput combined with ARQ protocols in networks than that of basic ARQ protocols. But packet combining scheme fails to correct errors when the errors occur in the same bit locations of two erroneous copies. In the present work, we propose a scheme that will correct error if the errors occur at the same bit location of the erroneous copies. The proposed scheme when combined with ARQ protocol will offer higher throughput. (author)

  8. Nuclear-chemistry research and spectroscopy with radioactive sources. Eighteenth annual progress report

    International Nuclear Information System (INIS)

    Fink, R.W.

    1982-01-01

    Progress is reported on nuclear spectroscopy studies including lifetimes of the g/sub 7/2/ shell-model intruder states in 107 109 Ag, lifetime of the new /sup 187m/Au isomer, the decay of 187 Au - 187 Pt, decay of /sup 201m,g/Po, 203 At, and 125 Ba, and L-shell orbital EC probability and decay energy in 207 Bi decay. Also progress on nuclear model calculations of nuclear structure is reported

  9. Charm-conserving strangeness-changing two body hadronic decays of charmed baryons

    International Nuclear Information System (INIS)

    Khanna, M.P.

    1993-10-01

    The charm-conserving strangeness-changing two body hadronic decays of charmed baryons are examined in the SU(4) symmetry scheme. In addition to the 20''-Hamiltonian, we consider a 15-piece of the weak Hamiltonian which may arise due to SU(4) breaking or due to some non-conventional dynamics. The numerical estimates for decay widths of some of the modes are presented. (author). 15 refs, 3 tabs

  10. Quark-mixing renormalization effects on the W-boson partial decay widths

    International Nuclear Information System (INIS)

    Almasy, A.A.; Kniehl, B.A.; Sirlin, A.

    2008-10-01

    We briefly review existing proposals for the renormalization of the Cabibbo- Kobayashi-Maskawa matrix and study their numerical effects on the W-boson partial decay widths. The differences between the decay widths predicted by the various renormalization schemes are generally negligible, while their deviations from the MS results are very small, except for W + → u anti b and W + →c anti b, where they reach approximately 4%. (orig.)

  11. Electron Screening Effects on α-decay

    Science.gov (United States)

    Musumarra, A.; Farinon, F.; Nociforo, C.; Geissel, H.; Baur, G.; Behr, K.-H.; Bonasera, A.; Bosch, F.; Boutin, D.; Brünle, A.; Chen, L.; Del Zoppo, A.; Dimopoulou, C.; Di Pietro, A.; Faestermann, T.; Figuera, P.; Hagino, K.; Janik, R.; Karagiannis, C.; Kienle, P.; Kimura, S.; Knöbel, R.; Kojouharov, I.; Kozhuharov, C.; Kuboki, T.; Kurcewicz, J.; Kurz, N.; Langanke, K.; Lattuada, M.; Litvinov, S. A.; Litvinov, Yu. A.; Martinez-Pinedo, G.; Mazzocco, M.; Montes, F.; Motizuki, Y.; Nolden, F.; Ohtsubo, T.; Okuma, Y.; Patyk, Z.; Pellegriti, M. G.; Plaß, W.; Pietri, S.; Podolyak, Z.; Prochazka, A.; Scheidenberger, C.; Scuderi, V.; Sitar, B.; Steck, M.; Strmen, P.; Sun, B.; Suzuki, T.; Szarka, I.; Torresi, D.; Weick, H.; Winfield, J. S.; Winkler, M.; Wollersheim, H. J.; Yamaguchi, T.

    2009-08-01

    An open problem in Nuclear Astrophysics concerns the understanding of electron-screening effects on nuclear reaction rates at stellar energies. In this framework, we have proposed to investigate the influence of the electron cloud on α-decay by measuring Q-values and α-decay half-lives of fully stripped, H-like and He-like ions. These kinds of measurements have been feasible just recently for highly-charged radioactive nuclides by fragmentation of 238U at relativistic energies at the FRS-ESR facility at GSI. In this way it is possible to produce, efficiently separate and store highly-charged α-emitters. Candidates for the proposed investigation were carefully selected and will be studied by using the Schottky Mass Spectroscopy technique. In order to establish a solid reference data set, lifetimes and Qα-value measurements of the corresponding neutrals have been performed directly at the FRS, by implanting the separated ions into an active Silicon stopper.

  12. Nuclear fuel accounting

    International Nuclear Information System (INIS)

    Aisch, D.E.

    1977-01-01

    After a nuclear power plant has started commercial operation the actual nuclear fuel costs have to be demonstrated in the rate making procedure. For this purpose an accounting system has to be developed which comprises the following features: 1) All costs associated with nuclear fuel shall be correctly recorded; 2) it shall be sufficiently flexible to cover also deviations from proposed core loading patterns; 3) it shall be applicable to different fuel cycle schemes. (orig./RW) [de

  13. Tritium decay helium-3 effects in tungsten

    Directory of Open Access Journals (Sweden)

    M. Shimada

    2017-08-01

    Full Text Available Tritium (T implanted by plasmas diffuses into bulk material, especially rapidly at elevated temperatures, and becomes trapped in neutron radiation-induced defects in materials that act as trapping sites for the tritium. The trapped tritium atoms will decay to produce helium-3 (3He atoms at a half-life of 12.3 years. 3He has a large cross section for absorbing thermal neutrons, which after absorbing a neutron produces hydrogen (H and tritium ions with a combined kinetic energy of 0.76 MeV through the 3He(n,HT nuclear reaction. The purpose of this paper is to quantify the 3He produced in tungsten by tritium decay compared to the neutron-induced helium-4 (4He produced in tungsten. This is important given the fact that helium in materials not only creates microstructural damage in the bulk of the material but alters surface morphology of the material effecting plasma-surface interaction process (e.g. material evolution, erosion and tritium behavior of plasma-facing component materials. Effects of tritium decay 3He in tungsten are investigated here with a simple model that predicts quantity of 3He produced in a fusion DEMO FW based on a neutron energy spectrum found in literature. This study reveals that: (1 helium-3 concentration was equilibrated to ∼6% of initial/trapped tritium concentration, (2 tritium concentration remained approximately constant (94% of initial tritium concentration, and (3 displacement damage from 3He(n,HT nuclear reaction became >1 dpa/year in DEMO FW.

  14. Exotic nuclei: α-decay, direct reactions and structure

    International Nuclear Information System (INIS)

    Jain, Arun K.

    2003-01-01

    With input parameters from the microscopic studies of stable nuclei and their variations with respect to energy, density, asymmetry etc. one expects to describe the decay of unstable nuclei, their microscopic structure and various scattering and reaction cross sections. The exotic nuclei, both in the lower-mass region as well as in the super-heavy region also should be accessible for predictions and verification. Somehow the direct nuclear reactions of the transfer and knockout type, employed to investigate quantitatively the microscopic behaviour of nuclei, have been only marginally successful. Successful resolution of some of the striking gross disagreements between theory and observations has been achieved now. The manner in which information of the microscopic structure and the effective nuclear interaction affect the predictive power of the direct reactions is found to be remarkable. In the α-decay of heavy nuclei also the microscopic structure information of the target and residual nuclei play decisive role in the values of decay energy and half-life. The interior and surface parts of the α-particle residual nucleus effective interaction, control the energy and decay rates. Fitting the observations with microscopic model values lead to the required predictive power for decay properties of super-heavy nuclei. In a similar manner the analysis of scattering and reactions involving light exotic-nuclei gives information about their microscopic structure. (author)

  15. Global analysis of inclusive B decays

    International Nuclear Information System (INIS)

    Bauer, Christian W.; Ligeti, Zoltan; Luke, Michael; Manohar, Aneesh; Trott, Michael

    2004-01-01

    In light of the large amount of new experimental data, we revisit the determination of |V cb | and m b from inclusive semileptonic and radiative B decays. We study shape variables to order Λ QCD 3 /m b 3 and α s 2 β 0 , and include the order α s Λ QCD /m b correction to the hadron mass spectrum in semileptonic decay, which improves the agreement with the data. We focus on the 1S and kinetic mass schemes for the b quark, with and without expanding m b -m c in HQET. We perform fits to all available data from BABAR, BELLE, CDF, CLEO, and DELPHI, discuss the theoretical uncertainties, and compare with earlier results. We find |V cb | = (41.9 ± 0.6 ± 0.1 τB ) x 10 -3 and m b 1S = 4.68 ± 0.04GeV, including our estimate of the theoretical uncertainty in the fit

  16. Nuclear transitions induced by atomic excitations

    International Nuclear Information System (INIS)

    Dyer, P.L.; Bounds, J.A.; Haight, R.C.; Luk, T.S.

    1988-01-01

    In the two-step pumping scheme for a gamma-ray laser, an essential step is that of exciting the nucleus from a long-lived storage isomer to a nearby short-lived state that then decays to the upper lasing level. An experiment is in progress to induce this transfer by first exciting the atomic electrons with uv photons. The incident photons couple well to the electrons, which then couple via a virtual photon to the nucleus. As a test case, excitation of the 235 U nucleus is being sought, using a high-brightness uv laser. The excited nuclear state, having a 26-minute half-life, decays by internal converison, resulting in emission of an atomic electron. A pulsed infrared laser produces an atomic beam of 235 U which is then bombarded by the uv laser beam. Ions are collected, and conversion electrons are detected by a channel elctron multiplier. In preliminary experiments, an upper limit of 7 x 10 -5 has been obtained for the probability of exciting a 235 U atom in the uv beam for one picosecond at an intensity of about 10 15 W/cm 2 . Experiments with higher sensitivities and at higher uv beam intensities are underway. 6 refs., 1 fig

  17. Lepton asymmetry in B decays

    International Nuclear Information System (INIS)

    Wolfenstein, L.

    1998-01-01

    An estimate of the possible magnitude of the lepton asymmetry in B d decay is given in terms of observables. The asymmetry in B s decays is also discussed. It is concluded that the lepton asymmetry is not useful for detecting new physics in B-bar B mixing. copyright 1998 The American Physical Society

  18. Tau decays: A theoretical perspective

    International Nuclear Information System (INIS)

    Marciano, W.J.

    1992-11-01

    Theoretical predictions for various tau decay rates are reviewed. Effects of electroweak radiative corrections are described. Implications for precision tests of the standard model and ''new physics'' searches are discussed. A perspective on the tau decay puzzle and 1-prong problem is given

  19. Beauty hadron decays at LHCb

    CERN Document Server

    Poluektov, Anton

    2016-01-01

    In these proceedings, I will report the recent results on properties, production and decays of beauty baryons, as well as measurements of B + c meson decays, based on data collected by the LHCb collaboration at the LHC collider in 2011–2012.

  20. Status of rare decay experiments

    Energy Technology Data Exchange (ETDEWEB)

    Littenberg, L.S.

    1984-01-01

    Some results are given for rare muon decay experiments currently running. Also, plans are discussed for rare kaon decay experiments. Some of the events sought come from processes which violate lepton flavor conservation. Several apparatuses used in the search are described. 35 references. (LEW)