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Sample records for actual nuclear decay

  1. Nuclear structure from radioactive decay

    SciTech Connect

    Wood, J.L.

    1991-09-30

    This report discusses nuclear structure from radioactive decay of the following: Neutron-Deficient Iridium Isotopes; Neutron-Deficient Platinum Isotopes; Neutron-Deficient Gold Isotopes; Neutron-Deficient Mercury Isotopes; Neutron-Deficient Thallium Isotopes; Neutron-Deficient Lead Isotopes; Neutron-Deficient Samarium Isotopes; Neutron-Deficient Promethium Isotopes; Neutron-Deficient Neodymium Isotopes; and Neutron-Deficient Praseodymium Isotopes. Also discussed are Nuclear Systematics and Models.

  2. Nuclear structure from radioactive decay

    SciTech Connect

    Wood, J.L.

    1990-09-30

    This report discusses the nuclear structure of the following isotopes as a result of radioactive decays: neutron-deficient iridium isotopes; neutron-deficient platinum isotopes; neutron-deficient gold isotopes; neutron-deficient mercury isotopes; neutron-deficient thallium isotopes; neutron-deficient lead isotopes; neutron-deficient promethium isotopes; and neutron-deficient samarium isotopes.

  3. Nuclear Data Compilation for Beta Decay Isotope

    NASA Astrophysics Data System (ADS)

    Olmsted, Susan; Kelley, John; Sheu, Grace

    2015-10-01

    The Triangle Universities Nuclear Laboratory nuclear data group works with the Nuclear Structure and Decay Data network to compile and evaluate data for use in nuclear physics research and applied technologies. Teams of data evaluators search through the literature and examine the experimental values for various nuclear structure parameters. The present activity focused on reviewing all available literature to determine the most accurate half-life values for beta unstable isotopes in the A = 3-20 range. This analysis will eventually be folded into the ENSDF (Evaluated Nuclear Structure Data File). By surveying an accumulated compilation of reference articles, we gathered all of the experimental half-life values for the beta decay nuclides. We then used the Visual Averaging Library, a data evaluation software package, to find half-life values using several different averaging techniques. Ultimately, we found recommended half-life values for most of the mentioned beta decay isotopes, and updated web pages on the TUNL webpage to reflect these evaluations. To summarize, we compiled and evaluated literature reports on experimentally determined half-lives. Our findings have been used to update information given on the TUNL Nuclear Data Evaluation group website. This was an REU project with Triangle Universities Nuclear Laboratory.

  4. Power spectrum analyses of nuclear decay rates

    NASA Astrophysics Data System (ADS)

    Javorsek, D.; Sturrock, P. A.; Lasenby, R. N.; Lasenby, A. N.; Buncher, J. B.; Fischbach, E.; Gruenwald, J. T.; Hoft, A. W.; Horan, T. J.; Jenkins, J. H.; Kerford, J. L.; Lee, R. H.; Longman, A.; Mattes, J. J.; Morreale, B. L.; Morris, D. B.; Mudry, R. N.; Newport, J. R.; O'Keefe, D.; Petrelli, M. A.; Silver, M. A.; Stewart, C. A.; Terry, B.

    2010-10-01

    We provide the results from a spectral analysis of nuclear decay data displaying annually varying periodic fluctuations. The analyzed data were obtained from three distinct data sets: 32Si and 36Cl decays reported by an experiment performed at the Brookhaven National Laboratory (BNL), 56Mn decay reported by the Children's Nutrition Research Center (CNRC), but also performed at BNL, and 226Ra decay reported by an experiment performed at the Physikalisch-Technische Bundesanstalt (PTB) in Germany. All three data sets exhibit the same primary frequency mode consisting of an annual period. Additional spectral comparisons of the data to local ambient temperature, atmospheric pressure, relative humidity, Earth-Sun distance, and their reciprocals were performed. No common phases were found between the factors investigated and those exhibited by the nuclear decay data. This suggests that either a combination of factors was responsible, or that, if it was a single factor, its effects on the decay rate experiments are not a direct synchronous modulation. We conclude that the annual periodicity in these data sets is a real effect, but that further study involving additional carefully controlled experiments will be needed to establish its origin.

  5. Decay heat studies for nuclear energy

    NASA Astrophysics Data System (ADS)

    Algora, A.; Jordan, D.; Taín, J. L.; Rubio, B.; Agramunt, J.; Caballero, L.; Nácher, E.; Perez-Cerdan, A. B.; Molina, F.; Estevez, E.; Valencia, E.; Krasznahorkay, A.; Hunyadi, M. D.; Gulyás, J.; Vitéz, A.; Csatlós, M.; Csige, L.; Eronen, T.; Rissanen, J.; Saastamoinen, A.; Moore, I. D.; Penttilä, H.; Kolhinen, V. S.; Burkard, K.; Hüller, W.; Batist, L.; Gelletly, W.; Nichols, A. L.; Yoshida, T.; Sonzogni, A. A.; Peräjärvi, K.

    2014-01-01

    The energy associated with the decay of fission products plays an important role in the estimation of the amount of heat released by nuclear fuel in reactors. In this article we present results of the study of the beta decay of some refractory isotopes that were considered important contributors to the decay heat in reactors. The measurements were performed at the IGISOL facility of the University of Jyväskylä, Finland. In these studies we have combined for the first time a Penning trap (JYFLTRAP), which was used as a high resolution isobaric separator, with a total absorption spectrometer. The results of the measurements as well as their consequences for decay heat summation calculations are discussed.

  6. Decay Data Evaluation Project: Evaluation of (52)Fe nuclear decay data.

    PubMed

    Luca, Aurelian

    2016-03-01

    Within the Decay Data Evaluation Project (DDEP) and the IAEA Coordinated Research Project no. F41029, the evaluation of the nuclear decay data of (52)Fe, a radionuclide of interest in nuclear medicine, was performed. The main nuclear decay data evaluated are: the half-life, decay energy, energies and probabilities of the electron capture and β(+) transitions, internal conversion coefficients and gamma-ray energies and emission intensities. This new evaluation, made using the DDEP methodology and tools, was included in the DDEP database NUCLEIDE.

  7. Imperfect World of beta beta-decay Nuclear Data Sets

    SciTech Connect

    Pritychenko, B.

    2015-01-03

    The precision of double-beta ββ-decay experimental half lives and their uncertainties is reanalyzed. The method of Benford's distributions has been applied to nuclear reaction, structure and decay data sets. First-digit distribution trend for ββ-decay T2v1/2 is consistent with large nuclear reaction and structure data sets and provides validation of experimental half-lives. A complementary analysis of the decay uncertainties indicates deficiencies due to small size of statistical samples, and incomplete collection of experimental information. Further experimental and theoretical efforts would lead toward more precise values of-decay half-lives and nuclear matrix elements.

  8. Nuclear structure notes on element 115 decay chains

    SciTech Connect

    Rudolph, D. Sarmiento, L. G.; Forsberg, U.

    2015-10-15

    Hitherto collected data on more than hundred α-decay chains stemming from element 115 are combined to probe some aspects of the underlying nuclear structure of the heaviest atomic nuclei yet created in the laboratory.

  9. Observation of the competitive double-gamma nuclear decay.

    PubMed

    Walz, C; Scheit, H; Pietralla, N; Aumann, T; Lefol, R; Ponomarev, V Yu

    2015-10-15

    The double-gamma (γγ)-decay of a quantum system in an excited state is a fundamental second-order process of quantum electrodynamics. In contrast to the well-known single-gamma (γ)-decay, the γγ-decay is characterized by the simultaneous emission of two γ quanta, each with a continuous energy spectrum. In nuclear physics, this exotic decay mode has only been observed for transitions between states with spin-parity quantum numbers J(π) = 0(+) (refs 1-3). Single-gamma decays-the main experimental obstacle to observing the γγ-decay-are strictly forbidden for these 0(+) → 0(+) transitions. Here we report the observation of the γγ-decay of an excited nuclear state (J(π) = 11/2(-)) that is directly competing with an allowed γ-decay (to ground state J(π) = 3/2(+)). The branching ratio of the competitive γγ-decay of the 11/2(-) isomer of (137)Ba to the ground state relative to its single γ-decay was determined to be (2.05 ± 0.37) × 10(-6). From the measured angular correlation and the shape of the energy spectra of the individual γ-rays, the contributing combinations of multipolarities of the γ radiation were determined. Transition matrix elements calculated using the quasiparticle-phonon model reproduce our measurements well. The γγ-decay rate gives access to so far unexplored important nuclear structure information, such as the generalized (off-diagonal) nuclear electric polarizabilities and magnetic susceptibilities.

  10. Observation of the competitive double-gamma nuclear decay.

    PubMed

    Walz, C; Scheit, H; Pietralla, N; Aumann, T; Lefol, R; Ponomarev, V Yu

    2015-10-15

    The double-gamma (γγ)-decay of a quantum system in an excited state is a fundamental second-order process of quantum electrodynamics. In contrast to the well-known single-gamma (γ)-decay, the γγ-decay is characterized by the simultaneous emission of two γ quanta, each with a continuous energy spectrum. In nuclear physics, this exotic decay mode has only been observed for transitions between states with spin-parity quantum numbers J(π) = 0(+) (refs 1-3). Single-gamma decays-the main experimental obstacle to observing the γγ-decay-are strictly forbidden for these 0(+) → 0(+) transitions. Here we report the observation of the γγ-decay of an excited nuclear state (J(π) = 11/2(-)) that is directly competing with an allowed γ-decay (to ground state J(π) = 3/2(+)). The branching ratio of the competitive γγ-decay of the 11/2(-) isomer of (137)Ba to the ground state relative to its single γ-decay was determined to be (2.05 ± 0.37) × 10(-6). From the measured angular correlation and the shape of the energy spectra of the individual γ-rays, the contributing combinations of multipolarities of the γ radiation were determined. Transition matrix elements calculated using the quasiparticle-phonon model reproduce our measurements well. The γγ-decay rate gives access to so far unexplored important nuclear structure information, such as the generalized (off-diagonal) nuclear electric polarizabilities and magnetic susceptibilities. PMID:26469051

  11. Investigation of Periodic Nuclear Decay Data with Spectral Analysis Techniques

    NASA Astrophysics Data System (ADS)

    Javorsek, D.; Sturrock, P.; Buncher, J.; Fischbach, E.; Gruenwald, T.; Hoft, A.; Horan, T.; Jenkins, J.; Kerford, J.; Lee, R.; Mattes, J.; Morris, D.; Mudry, R.; Newport, J.; Petrelli, M.; Silver, M.; Stewart, C.; Terry, B.; Willenberg, H.

    2009-12-01

    We provide the results from a spectral analysis of nuclear decay experiments displaying unexplained periodic fluctuations. The analyzed data was from 56Mn decay reported by the Children's Nutrition Research Center in Houston, 32Si decay reported by an experiment performed at the Brookhaven National Laboratory, and 226Ra decay reported by an experiment performed at the Physikalisch-Technische-Bundesanstalt in Germany. All three data sets possess the same primary frequency mode consisting of an annual period. Additionally a spectral comparison of the local ambient temperature, atmospheric pressure, relative humidity, Earth-Sun distance, and the plasma speed and latitude of the heliospheric current sheet (HCS) was performed. Following analysis of these six possible causal factors, their reciprocals, and their linear combinations, a possible link between nuclear decay rate fluctuations and the linear combination of the HCS latitude and 1/R motivates searching for a possible mechanism with such properties.

  12. Progress in Electromagnetic Alteration of Nuclear Decay Properties

    NASA Astrophysics Data System (ADS)

    Casperson, R. J.; Hughes, R. O.; Burke, J. T.; Scielzo, N. D.; Soufli, R.

    2014-03-01

    Significant alteration of nuclear decay properties would have important consequences, ranging from novel approaches to nuclear batteries and gamma-ray lasers, to improved viability for physics experiments with short-lived targets. Quantum systems that decay by photon emission must couple to the electromagnetic modes of the local environment, and by modifying these modes, one can manipulate the rate of spontaneous emission. The nuclear isomer 235mU is low-energy, long-lived, and is easily populated through 239Pu α-decay, which makes it an excellent benchmark for this effect. The decay rate of this isomer in a variety of environments is currently under investigation. Implications of this work will be discussed, and first results will be presented. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  13. Progress in Electromagnetic Alteration of Nuclear Decay Properties

    NASA Astrophysics Data System (ADS)

    Casperson, R. J.; Burke, J. T.; Hughes, R. O.; Scielzo, N. D.; Soufli, R.

    2013-10-01

    Significant alteration of nuclear decay properties would have important consequences, ranging from novel approaches to nuclear batteries and gamma-ray lasers, to improved viability for physics experiments with short-lived targets. Quantum systems that decay by photon emission must couple to the electromagnetic modes of the local environment, and by modifying these modes, one can manipulate the rate of spontaneous emission. The nuclear isomer 235mU is low-energy, long-lived, and is easily populated through 239Pu α-decay, which makes it an excellent benchmark for this effect. The decay rate of this isomer in a variety of environments is currently under investigation. Implications of this work will be discussed, and first results will be presented. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  14. Nuclear Decay Data Evaluations at IFIN-HH, Romania

    SciTech Connect

    Luca, A.

    2014-06-15

    An IAEA Coordinated Research Project (CRP) on Updated Decay Data Library for Actinides was implemented during the period 2005-2012. The author participated in the CRP, as a representative of the Horia Hulubei National Institute of Physics and Nuclear Engineering (IFIN-HH), the Radionuclide Metrology Laboratory. Decay data for five actinide nuclides were evaluated by the author, according to the procedures and rules of the international cooperation Decay Data Evaluation Project (DDEP): {sup 236}U, {sup 234}Th, {sup 228}Ra, {sup 211}Bi and {sup 211}Po. The most important results, conclusions and some recommendations of the evaluator are presented. The IFIN-HH involvement in several new international and national research projects in the field is briefly mentioned; new evaluations and experimental determination of some nuclear decay data (photon absolute emission probability, half-life) for nuclear medicine applications are foreseen.

  15. Nuclear Decay Data Evaluations at IFIN-HH, Romania

    NASA Astrophysics Data System (ADS)

    Luca, A.

    2014-06-01

    An IAEA Coordinated Research Project (CRP) on Updated Decay Data Library for Actinides was implemented during the period 2005-2012. The author participated in the CRP, as a representative of the Horia Hulubei National Institute of Physics and Nuclear Engineering (IFIN-HH), the Radionuclide Metrology Laboratory. Decay data for five actinide nuclides were evaluated by the author, according to the procedures and rules of the international cooperation Decay Data Evaluation Project (DDEP): 236U, 234Th, 228Ra, 211Bi and 211Po. The most important results, conclusions and some recommendations of the evaluator are presented. The IFIN-HH involvement in several new international and national research projects in the field is briefly mentioned; new evaluations and experimental determination of some nuclear decay data (photon absolute emission probability, half-life) for nuclear medicine applications are foreseen.

  16. Influences of the astrophysical environment on nuclear decay rates

    SciTech Connect

    Norman, E.B.

    1987-09-01

    In many astronomical environments, physical conditions are so extreme that nuclear decay rates can be significantly altered from their laboratory values. Such effects are relevant to a number of current problems in nuclear astrophysics. Experiments related to these problems are now being pursued, and will be described in this talk. 19 refs., 5 figs.

  17. Microscopic description of complex nuclear decay: Multimodal fission

    NASA Astrophysics Data System (ADS)

    Staszczak, A.; Baran, A.; Dobaczewski, J.; Nazarewicz, W.

    2009-07-01

    Our understanding of nuclear fission, a fundamental nuclear decay, is still incomplete due to the complexity of the process. In this paper, we describe a study of spontaneous fission using the symmetry-unrestricted nuclear density functional theory. Our results show that the observed bimodal fission can be explained in terms of pathways in multidimensional collective space corresponding to different geometries of fission products. We also predict a new phenomenon of trimodal spontaneous fission for some rutherfordium, seaborgium, and hassium isotopes.

  18. Microscopic description of complex nuclear decay: Multimodal fission

    SciTech Connect

    Staszczak, A.; Baran, A.; Dobaczewski, J.; Nazarewicz, W.

    2009-07-15

    Our understanding of nuclear fission, a fundamental nuclear decay, is still incomplete due to the complexity of the process. In this paper, we describe a study of spontaneous fission using the symmetry-unrestricted nuclear density functional theory. Our results show that the observed bimodal fission can be explained in terms of pathways in multidimensional collective space corresponding to different geometries of fission products. We also predict a new phenomenon of trimodal spontaneous fission for some rutherfordium, seaborgium, and hassium isotopes.

  19. Possible Stimulation of Nuclear alpha Decay by Superfluid Helium

    SciTech Connect

    Barabanov, A. L.

    2009-08-28

    It is suggested that superfluid helium (condensate of {sup 4}He atoms) may stimulate nuclear alpha decay in a situation when an alpha emitter moves through superfluid helium with fine-tuned velocity, so that the backward-emitted alpha particle is at rest in the laboratory frame. It is shown that the probability of stimulated alpha decay in this case may be sizable enough to be detected.

  20. Possible stimulation of nuclear alpha decay by superfluid helium.

    PubMed

    Barabanov, A L

    2009-08-28

    It is suggested that superfluid helium (condensate of (4)He atoms) may stimulate nuclear alpha decay in a situation when an alpha emitter moves through superfluid helium with fine-tuned velocity, so that the backward-emitted alpha particle is at rest in the laboratory frame. It is shown that the probability of stimulated alpha decay in this case may be sizable enough to be detected.

  1. Evidence for a Solar Influence on Nuclear Decay Rates

    NASA Astrophysics Data System (ADS)

    Sturrock, Peter A.; Buncher, J. B.; Fischbach, E.; Gruenwald, J. T.; Javorsek, D., II; Jenkins, J. H.; Lee, R.; Mattes, J. T.; Newport, J. R.

    2010-05-01

    Analyses of data acquired during two experiments at the Brookhaven National Laboratory (BNL) and one at the Physikalisch-Technische Bundesanstalt in Germany have yielded strong evidence for an annual variation of some nuclear decay rates. Since the Sun-Earth distance has an annual period, it is possible that some radiation from the Sun plays a role. We here present evidence in support of this conjecture. The low-energy solar-neutrino flux as detected by the Homestake and GALLEX experiments, and the total solar irradiance as measured by the ACRIM experiment, both exhibit a periodicity of about 12 year-1. We infer that the solar core rotates at this synodic frequency, and that nuclear burning in the core is not spherically symmetric. If neutrinos influence some decay rates, the same periodicity may be manifested in decay measurements. We have for this reason carried out a power-spectrum analysis of measurements made at BNL over a 7-year interval of the decay rates of 32Si and 36Cl. This analysis yields strong evidence for a cluster of periodicities centered on 12 year-1, such as one might obtain from stochastic fluctuations of nuclear burning in a rotating core. These results imply that some nuclear decay rates are influenced either by solar neutrinos or by some other form of radiation that has its origin in the solar core. This work was supported by the NSF grant AST-0607572 and DOE grant DE-AC-02-76ER071428.

  2. Nuclear isospin asymmetry in α decay of heavy nuclei

    NASA Astrophysics Data System (ADS)

    Shin, Eunkyoung; Lim, Yeunhwan; Hyun, Chang Ho; Oh, Yongseok

    2016-08-01

    The effects of nuclear isospin asymmetry on α -decay lifetimes of heavy nuclei are investigated within various phenomenological models of the nuclear potential for the α particle. We consider the widely used simple square-well potential and Woods-Saxon potential and modify them by including an isospin asymmetry term. We then suggest a model for the potential of the α particle motivated by a microscopic phenomenological approach of the Skyrme force model, which naturally introduces the isospin-dependent form of the nuclear potential for the α particle. The empirical α -decay lifetime formula of Viola and Seaborg [J. Inorg. Nucl. Chem. 28, 741 (1966), 10.1016/0022-1902(66)80412-8] is also modified to include isospin asymmetry effects. The obtained α -decay half-lives are in good agreement with the experimental data, and we find that including the nuclear isospin effects somehow improves the theoretical results for α -decay half-lives. The implications of these results are discussed, and the predictions on the α -decay lifetimes of superheavy elements are also presented.

  3. Nuclear structure from radioactive decay. Annual progress report

    SciTech Connect

    Wood, J.L.

    1991-09-30

    This report discusses nuclear structure from radioactive decay of the following: Neutron-Deficient Iridium Isotopes; Neutron-Deficient Platinum Isotopes; Neutron-Deficient Gold Isotopes; Neutron-Deficient Mercury Isotopes; Neutron-Deficient Thallium Isotopes; Neutron-Deficient Lead Isotopes; Neutron-Deficient Samarium Isotopes; Neutron-Deficient Promethium Isotopes; Neutron-Deficient Neodymium Isotopes; and Neutron-Deficient Praseodymium Isotopes. Also discussed are Nuclear Systematics and Models.

  4. Nuclear matrix elements for double-β decay

    SciTech Connect

    Engel, Jonathan

    2015-07-15

    Recent progress in nuclear-structure theory has been dramatic. I describe applications in progress of ab inito calculations to double-beta decay, and discuss the recent and future application of generator-coordinate methods to the same problem. I also discuss the old and vexing problem of the renormalization of the weak nuclear axial-vector coupling constant “in medium” and plans to resolve it.

  5. Nudat: Nuclear Structure and Decay Data from the National Nuclear Data Center (NNDC)

    DOE Data Explorer

    NuDat allows users to search and plot nuclear structure and decay data interactively. NuDat was developed by the National Nuclear Data Center (NNDC)but utilizes contributions from physicists around the world. It provides an interface between web users and several databases containing nuclear structure, nuclear decay and some neutron-induced nuclear reaction information. Users can search for nuclear level properties (energy, half-life, spinparity), gamma-ray information (energy, intensity, multipolarity, coincidences), radiation information following nuclear decay (energy, intensity, dose), and neutron-induced reaction data from the BNL-325 book (thermal cross section and resonance integral). The information provided by NuDat 2 can be viewed in tables, level schemes and an interactive chart of nuclides.

  6. Nuclear decay data files of the Dosimetry Research Group

    SciTech Connect

    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.

  7. Evidence against solar influence on nuclear decay constants

    NASA Astrophysics Data System (ADS)

    Pommé, S.; Stroh, H.; Paepen, J.; Van Ammel, R.; Marouli, M.; Altzitzoglou, T.; Hult, M.; Kossert, K.; Nähle, O.; Schrader, H.; Juget, F.; Bailat, C.; Nedjadi, Y.; Bochud, F.; Buchillier, T.; Michotte, C.; Courte, S.; van Rooy, M. W.; van Staden, M. J.; Lubbe, J.; Simpson, B. R. S.; Fazio, A.; De Felice, P.; Jackson, T. W.; Van Wyngaardt, W. M.; Reinhard, M. I.; Golya, J.; Bourke, S.; Roy, T.; Galea, R.; Keightley, J. D.; Ferreira, K. M.; Collins, S. M.; Ceccatelli, A.; Unterweger, M.; Fitzgerald, R.; Bergeron, D. E.; Pibida, L.; Verheyen, L.; Bruggeman, M.; Vodenik, B.; Korun, M.; Chisté, V.; Amiot, M.-N.

    2016-10-01

    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.

  8. Nuclear Properties and Decay Data Chart of Nuclides.

    2008-04-04

    Version 00 NUCHART displays nuclear decay data graphically on a PC and, includes a search routine for assigning gamma-ray energies to radionuclides. The numerical data included in NUCHART were taken from the online database "NUDAT" Version of March 1994. The following information is presented: (1) Nuclide information: for each nuclide, abundance, mass excess, (main) decay mode, half-life and uncertainty, branching ratio, decay Q; (2) decay radiation: for each nuclide, tables of radiation energy, intensity andmore » equivalent dose for the 5 most intense decay radiations of beta+, beta-, conversion electrons, gammas, alphas and x-rays, including electron Augers; (3) adopted gammas: for each nuclide, table containing energy, relative intensity, energy level of the main gamma lines and year of publication in Nuclear Data Sheets; (4) search gamma energies: for a specified interval of gamma energies all know gamma lines and their nuclides are displayed; the database contains 132,000 gamma lines; (5) a search mode by specific nuclide is also available. For the latest data and online tools for viewing the data, see NuDat 2.4 on the NNDC and IAEA NDS websites: http://www.nndc.bnl.gov/ and http://www-nds.iaea.org/.« less

  9. Nuclear Properties and Decay Data Chart of Nuclides.

    SciTech Connect

    OSORIO, V. B.

    2008-04-04

    Version 00 NUCHART displays nuclear decay data graphically on a PC and, includes a search routine for assigning gamma-ray energies to radionuclides. The numerical data included in NUCHART were taken from the online database "NUDAT" Version of March 1994. The following information is presented: (1) Nuclide information: for each nuclide, abundance, mass excess, (main) decay mode, half-life and uncertainty, branching ratio, decay Q; (2) decay radiation: for each nuclide, tables of radiation energy, intensity and equivalent dose for the 5 most intense decay radiations of beta+, beta-, conversion electrons, gammas, alphas and x-rays, including electron Augers; (3) adopted gammas: for each nuclide, table containing energy, relative intensity, energy level of the main gamma lines and year of publication in Nuclear Data Sheets; (4) search gamma energies: for a specified interval of gamma energies all know gamma lines and their nuclides are displayed; the database contains 132,000 gamma lines; (5) a search mode by specific nuclide is also available. For the latest data and online tools for viewing the data, see NuDat 2.4 on the NNDC and IAEA NDS websites: http://www.nndc.bnl.gov/ and http://www-nds.iaea.org/.

  10. Total Absorption Study of Beta Decays Relevant for Nuclear Applications and Nuclear Structure

    SciTech Connect

    Algora, A.; Valencia, E.; Taín, J.L.; Jordan, M.D.; Agramunt, J.; Rubio, B.; Estevez, E.; Molina, F.; Montaner, A.; Guadilla, V.; Fallot, M.; Porta, A.; Zakari-Issoufou, A.-A.; Bui, V.M.; and others

    2014-06-15

    An overview is given of our activities related to the study of the beta decay of neutron rich nuclei relevant for nuclear applications. Recent results of the study of the beta decay of {sup 87,88}Br using a new segmented total absorption spectrometer are presented. The measurements were performed at the IGISOL facility using trap-assisted total absorption spectroscopy.

  11. Total Absorption Study of Beta Decays Relevant for Nuclear Applications and Nuclear Structure

    SciTech Connect

    Algora, A.; Valencia, E.; Tain, J. L.; Jordan, M. D.; Agramunt, J.; Rubio, B.; Estevez, E.; Molina, F.; Montaner, A.; Guadilla, V.; Fallot, M.; Podolyak, Zs.; Regan, P. H.; Gelletly, W.; Bowry, M.; Mason, P.; Farrelly, G. F.; Rissanen, J.; Eronen, T.; Moore, I.; Penttila, H.; Aysto, J.; Eloma, V.; Hakala, J.; Jokinen, A.; Kolkinen, V.; Reponen, M.; Sonnenschein, V.; Cano-Ott, D.; Martinez, T.; Mendoza, E.; Garcia, A. R.; Gomez-Hornillos, M. B.; Gorlychev, V.; Caballero-Folch, R.; Kondev, F. G.; Sonzogni, A. A.

    2014-06-01

    We present an overview of our activities related to the study of the beta decay of neutron rich nuclei relevant for nuclear applications. Recent results of the study of the beta decay of Br using a new segmented total absorption spectrometer are presented. Our measurements were performed at the IGISOL facility using trap-assisted total absorption spectroscopy.

  12. Total Absorption Study of Beta Decays Relevant for Nuclear Applications and Nuclear Structure

    NASA Astrophysics Data System (ADS)

    Algora, A.; Valencia, E.; Taín, J. L.; Jordan, M. D.; Agramunt, J.; Rubio, B.; Estevez, E.; Molina, F.; Montaner, A.; Guadilla, V.; Fallot, M.; Porta, A.; Zakari-Issoufou, A.-A.; Bui, V. M.; Rice, S.; Podolyák, Zs.; Regan, P. H.; Gelletly, W.; Bowry, M.; Mason, P.; Farrelly, G. F.; Rissanen, J.; Eronen, T.; Moore, I.; Penttilä, H.; Äystö, J.; Eloma, V.; Hakala, J.; Jokinen, A.; Kolkinen, V.; Reponen, M.; Sonnenschein, V.; Cano-Ott, D.; Martínez, T.; Mendoza, E.; Garcia, A. R.; Gomez-Hornillos, M. B.; Gorlychev, V.; Caballero-Folch, R.; Kondev, F. G.; Sonzogni, A. A.

    2014-06-01

    An overview is given of our activities related to the study of the beta decay of neutron rich nuclei relevant for nuclear applications. Recent results of the study of the beta decay of 87,88Br using a new segmented total absorption spectrometer are presented. The measurements were performed at the IGISOL facility using trap-assisted total absorption spectroscopy.

  13. Studies of Nuclear Structure and Decay Properties of Actinide Nuclei

    SciTech Connect

    Kondev, F. G.; Ahmad, I.; Carpenter, M. P.; Chiara, C. J.; Greene, J. P.; Janssens, R. V. F.; Khoo, T. L.; Lauritsen, T.; Lister, C. J.; Moore, E. F.; Seweryniak, D.; Zhu, S.; Kellett, M. A.; Nichols, A. L.

    2009-01-28

    The identification of single-particle states in heavy actinide nuclei by means of studying their decay schemes plays a seminal role in understanding the structure of the heaviest elements and testing the predictive power of modern theoretical models. The heaviest odd-mass nuclides available in sufficient quantity for detailed decay spectroscopic studies are 20-h {sup 255} Fm(for neutrons) and 20-d {sup 253}Es(for protons). Decay spectra of these isotopes, together with those for the odd-odd 276-d {sup 254}Es nuclide, were measured using a variety of {alpha}-particle and {gamma}-ray spectroscopy techniques. Well-defined decay data are also essential pre-requisites for the detection and accurate characterization of fissile radionuclides. The parameters of greatest relevance include actinide half-lives, branching fractions, and {alpha}-particle and {gamma}-ray energies and emission probabilities. Their quantification to good accuracy provides the means of monitoring their presence, behavior and transport in nuclear facilities as well as any clandestine movement and usage. As a consequence of recommendations made at recent IAEA research coordination meetings on 'Updated Decay Data Library for Actinides,' measurements were undertaken to determine specific decay data of the more inadequately defined radionuclides.

  14. Neutrinoless double-β decay and nuclear transition matrix elements

    SciTech Connect

    Rath, P. K.

    2015-10-28

    Within mechanisms involving the light Majorana neutrinos, squark-neutrino, Majorons, sterile neutrinos and heavy Majorana neutrino, nuclear transition matrix elements for the neutrinoless (β{sup −}β{sup −}){sub 0ν} decay of {sup 96}Zr, {sup 100}Mo, {sup 128,130}Te and {sup 150}Nd nuclei are calculated by employing the PHFB approach. Effects due to finite size of nucleons, higher order currents, short range correlations, and deformations of parent as well as daughter nuclei on the calculated matrix elements are estimated. Uncertainties in nuclear transition matrix elements within long-ranged mechanisms but for double Majoron accompanied (β{sup −}β{sup −}ϕϕ){sub 0ν} decay modes are 9%–15%. In the case of short ranged heavy Majorona neutrino exchange mechanism, the maximum uncertainty is about 35%. The maximum systematic error within the mechanism involving the exchange of light Majorana neutrino is about 46%.

  15. Evaluation of the 125Sb nuclear decay data

    NASA Astrophysics Data System (ADS)

    Lile, Liu; Xiaolong, Huang; Mengxiao, Kang; Guochang, Chen; Jimin, Wang; Liyang, Jiang

    2016-02-01

    Evaluation of the complete decay scheme and data for 125Sb/125mTe decay to nuclear levels in 125Te is presented in this report; literature data available up to June 2015 are included. The Limitation of Relative Statistical Weight Method (LRSW) was applied to average numbers throughout the evaluation. The uncertainty assigned to the average value was always greater than or equal to the smallest uncertainty of the values used to calculate the average. The half-life has been determined to be 1007.4±0.3 days. All known measured γ-ray absolute or relative intensities have been examined; the γ-ray emission probability of the reference γ-ray line of 427.874 keV is recommended to be 29.54±0.10%. The theoretical internal conversion coefficients and their uncertainties were used to obtain the complete decay scheme intensity balance. The values of other decay characteristics were calculated using the ENSDF analysis program. Finally the updated decay scheme for 125Sb is presented.

  16. Nuclear-structure aspects of double beta decay

    SciTech Connect

    Suhonen, Jouni

    2010-11-24

    Neutrinoless double beta (0{nu}{beta}{beta}) decay of nuclei is a process that requires the neutrino to be a massive Majorana particle and thus cannot proceed in the standard model of electro-weak interactions. Recent results of the neutrino-oscillation experiments have produced accurate information on the mixing of neutrinos and their squared mass differences. The 0{nu}{beta}{beta} decay takes place in atomic nuclei where it can be observed, at least in principle, by underground neutrino experiments. The need of nuclei in observation of the 0{nu}{beta}{beta} decay bears two facets: The nucleus serves as laboratory for detection but at the same time its complicated many-nucleon structure interferes strongly with the analysis of the experimental data. The information about the weak-interaction observables, like the neutrino mass, has to be filtered from the data through the nuclear matrix elements (NMEs). Hence, exact knowledge about the NMEs is of paramount importance in the analysis of the data provided by the expensive and time-consuming underground experiments.

  17. Shell model nuclear matrix elements for competing mechanisms contributing to double beta decay

    SciTech Connect

    Horoi, Mihai

    2013-12-30

    Recent progress in the shell model approach to the nuclear matrix elements for the double beta decay process are presented. This includes nuclear matrix elements for competing mechanisms to neutrionless double beta decay, a comparison between closure and non-closure approximation for {sup 48}Ca, and an updated shell model analysis of nuclear matrix elements for the double beta decay of {sup 136}Xe.

  18. Microscopic Description of Complex Nuclear Decay: Multimodal Fission

    SciTech Connect

    Staszczak, A.; Baran, A.; Dobaczewski, J.; Nazarewicz, Witold

    2009-01-01

    This year marks the 70th anniversary of the discovery of nuclear fission. While there is little question of the societal importance of fission (e.g., to current and future energy needs), our understanding of this process is still fairly rudimentary due to the intricacy of the problem. Theoretically, fission represents an extreme example of the large-amplitude collective motion: the tunneling of a large, self-bound, superfluid system of mutually interacting particles. In this work, we describe a study of spontaneous fission using the self-consistent nuclear density functional theory and state-of-the-art computational tools. We did not impose any symmetry on the mean field so that the nuclear densities were allowed to acquire arbitrary shapes characterized by elongation, reflection-asymmetry, triaxiality, necking, etc. Here we show that the observed half-lives of nuclei undergoing bimodal fission can be explained in terms of competing pathways corresponding to different geometries of fission products. This is an important step in providing a many-body description of fundamental nuclear decay.

  19. New studies of nuclear decay {gamma}-rays from novae

    SciTech Connect

    Starrfield, S.; Truran, J.W.; Wiescher, M.C.

    1997-11-01

    The cause of the nova outburst is a thermonuclear runaway (TNR) in hydrogen rich material transferred by a companion onto a white dwarf. Studies of this phenomenon have shown that the TNR produces large concentrations of the short lived positron unstable isotopes of the CNO nuclei which are transported to the surface by convection so that early in the outburst we expect significant numbers of radioactive decays to occur at the surface. The resulting {gamma}-ray emission may be detectable from nearby novae early in their outbursts. The TNR is also expected to produce substantial amounts of {sup 7}Be and {sup 22}Na. Their decays also yield potentially detectable levels of {gamma}-ray emission for relatively nearby novae. We are also interested in the role played by novae in the production of the {approximately}2M{circle_dot} of {sup 26}Al found in the galaxy. In order to improve our predictions of this phenomenon, we have performed a new set of calculations of TNR`s on ONeMg and CO white dwarfs with an updated nuclear reaction network and opacities.

  20. Nuclear Decay Data: On-going Studies to Address and Improve Radionuclide Decay Characteristics

    NASA Astrophysics Data System (ADS)

    Nichols, Alan L.

    2005-05-01

    Representative decay data studies are described and reviewed, ranging from various measurement programmes to the maintenance of evaluated decay-data libraries. Gross beta-decay measurements are essential to address the decay-data requirements for short-lived fission products, well-defined half-lives are required in assessments of the storage of long-lived radionuclides in waste depositories, and improved decay data continue to be demanded in safeguards, to improve detector-calibration standards, and for medical and analytical applications. Such needs require the measurement of good quality decay data, along with multinational evaluations of decay schemes by means of agreed procedures.

  1. A triggerless digital data acquisition system for nuclear decay experiments

    SciTech Connect

    Agramunt, J.; Tain, J. L.; Albiol, F.; Algora, A.; Estevez, E.; Giubrone, G.; Jordan, M. D.; Molina, F.; Rubio, B.; Valencia, E.

    2013-06-10

    In nuclear decay experiments an important goal of the Data Acquisition (DAQ) system is to allow the reconstruction of time correlations between signals registered in different detectors. Classically DAQ systems are based in a trigger that starts the event acquisition, and all data related with the event of that trigger are collected as one compact structure. New technologies and electronics developments offer new possibilities to nuclear experiments with the use of sampling ADC-s. This type of ADC-s is able to provide the pulse shape, height and a time stamp of the signal. This new feature (time stamp) allows new systems to run without an event trigger. Later, the event can be reconstructed using the time stamp information. In this work we present a new DAQ developed for {beta}-delayed neutron emission experiments. Due to the long moderation time of neutrons, we opted for a self-trigger DAQ based on commercial digitizers. With this DAQ a negligible acquisition dead time was achieved while keeping a maximum of event information and flexibility in time correlations.

  2. A triggerless digital data acquisition system for nuclear decay experiments

    NASA Astrophysics Data System (ADS)

    Agramunt, J.; Tain, J. L.; Albiol, F.; Algora, A.; Estevez, E.; Giubrone, G.; Jordan, M. D.; Molina, F.; Rubio, B.; Valencia, E.

    2013-06-01

    In nuclear decay experiments an important goal of the Data Acquisition (DAQ) system is to allow the reconstruction of time correlations between signals registered in different detectors. Classically DAQ systems are based in a trigger that starts the event acquisition, and all data related with the event of that trigger are collected as one compact structure. New technologies and electronics developments offer new possibilities to nuclear experiments with the use of sampling ADC-s. This type of ADC-s is able to provide the pulse shape, height and a time stamp of the signal. This new feature (time stamp) allows new systems to run without an event trigger. Later, the event can be reconstructed using the time stamp information. In this work we present a new DAQ developed for β-delayed neutron emission experiments. Due to the long moderation time of neutrons, we opted for a self-trigger DAQ based on commercial digitizers. With this DAQ a negligible acquisition dead time was achieved while keeping a maximum of event information and flexibility in time correlations.

  3. Nuclear Decay Data in the MIRD (Medical Internal Radiation Dose) Format

    DOE Data Explorer

    MIRD is a database of evaluated nuclear decay data for over 2,100 radioactive nuclei. Data are extracted from ENSDF, processed by the program RadList, and used for medical internal radiation dose calculations. When using the MIRD interface, tables of nuclear and atomic radiations from nuclear decay and decay scheme drawings will be produced in the MIRD format from the Evaluated Nuclear Structure Data File (ENSDF) for the specified nuclide. Output may be either HTML-formatted tables and JPEG drawings, PostScript tables and drawings, or PDF tables and drawings.

  4. Decay data of radionuclides along the valley of nuclear stability for astrophysical applications.

    PubMed

    Chechev, Valery P; Huang, Xiaolong

    2015-11-01

    Several directions of the demand for decay data in nuclear astrophysics are discussed for radionuclides near the valley of nuclear stability. The current half-life and gamma-ray intensity evaluation results are presented for some radionuclides of astrophysical interest. An extended list of such nuclides is offered for their nuclear characteristics to be further evaluated by the Decay Data Evaluation Project collaboration participants. PMID:26275948

  5. Inhomogeneous dynamic nuclear polarization and suppression of electron polarization decay in a quantum dot

    NASA Astrophysics Data System (ADS)

    Wu, Na; Ding, Wenkui; Shi, Anqi; Zhang, Wenxian

    2016-08-01

    We investigate the dynamic nuclear polarization in a quantum dot. Due to the suppression of direct dipolar and indirect electron-mediated nuclear spin interactions by frequently injected electron spins, our analytical results under independent spin approximation agree well with quantum numerical simulations for a small number of nuclear spins. We find that the acquired nuclear polarization is highly inhomogeneous, proportional to the square of the local electron-nuclear hyperfine interaction constant. Starting from the inhomogeneously polarized nuclear spins, we further show that the electron polarization decay time can be extended 100 times even at a relatively low nuclear polarization.

  6. Double-β decay nuclear structure via electron capture on ^116In

    NASA Astrophysics Data System (ADS)

    Wrede, C.; Sjue, S. K. L.; García, A. A.; Swanson, H. E.; Ahmad, I.; Algora, A.; Elomaa, V.-V.; Eronen, T.; Hakala, J.; Jokinen, A.; Kolhinen, V. S.; Moore, I. D.; Penttilä, H.; Reponen, M.; Rissanen, J.; Saastamoinen, A.; Äystö, J.

    2013-04-01

    The small electron-capture decay branch of ^116In has been measured using Penning trap assisted decay spectroscopy. The deduced Gamow-Teller transition strength helps to resolve longstanding differences between scattered charge-exchange reaction values and a previous electron-capture decay value that was less statistically significant than the present one. We argue that this transition can now be used as a reliable benchmark for nuclear-structure calculations of the matrix element for the neutrinoless double-β decay of ^116Cd and other nuclides.

  7. Influence of Pairing on the Nuclear Matrix Elements of the Neutrinoless {beta}{beta} Decays

    SciTech Connect

    Caurier, E.; Nowacki, F.

    2008-02-08

    We study in this Letter the neutrinoless double beta decay nuclear matrix elements (NME's) in the framework of the interacting shell model. We analyze them in terms of the total angular momentum of the decaying neutron pair and as a function of the seniority truncations in the nuclear wave functions. This point of view turns out to be very adequate to gauge the accuracy of the NME's predicted by different nuclear models. In addition, it gives back the protagonist role in this process to the pairing interaction, the one which is responsible for the very existence of double beta decay emitters. We show that low seniority approximations, comparable to those implicit in the quasiparticle RPA in a spherical basis, tend to overestimate the NME's in several decays.

  8. Shell-model analysis of the 136Xe double beta decay nuclear matrix elements.

    PubMed

    Horoi, M; Brown, B A

    2013-05-31

    Neutrinoless double beta decay, if observed, could distinguish whether the neutrino is a Dirac or a Majorana particle, and it could be used to determine the absolute scale of the neutrino masses. 136Xe is one of the most promising candidates for observing this rare event. However, until recently there were no positive results for the allowed and less rare two-neutrino double beta decay mode. The small nuclear matrix element associated with the long half-life represents a challenge for nuclear structure models used for its calculation. We report a new shell-model analysis of the two-neutrino double beta decay of 136Xe, which takes into account all relevant nuclear orbitals necessary to fully describe the associated Gamow-Teller strength. We further use the new model to analyze the main contributions to the neutrinoless double beta decay matrix element, and show that they are also diminished.

  9. Modeling Nuclear Decay: A Point of Integration between Chemistry and Mathematics.

    ERIC Educational Resources Information Center

    Crippen, Kent J.; Curtright, Robert D.

    1998-01-01

    Describes four activities that use graphing calculators to model nuclear-decay phenomena. Students ultimately develop a notion about the radioactive waste produced by nuclear fission. These activities are in line with national educational standards and allow for the integration of science and mathematics. Contains 13 references. (Author/WRM)

  10. Development of the NPL gamma-ray spectrometer NANA for traceable nuclear decay and structure studies.

    PubMed

    Lorusso, G; Shearman, R; Regan, P H; Judge, S M; Bell, S; Collins, S M; Larijani, C; Ivanov, P; Jerome, S M; Keightley, J D; Lalkovski, S; Pearce, A K; Podolyak, Zs

    2016-03-01

    We present a brief report on the progress towards the construction of the National Nuclear Array (NANA), a gamma-ray coincidence spectrometer for discrete-line nuclear structure and decay measurements. The proposed spectrometer will combine a gamma-ray energy resolution of approximately 3% at 1MeV with sub-nanosecond timing discrimination between successive gamma rays in mutually coincident decay cascades. We also review a number of recent measurements using coincidence fast-timing gamma-ray spectroscopy for nuclear structure studies, which have helped to inform the design criteria for the NANA spectrometer.

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

    SciTech Connect

    Ricard-McCutchan, E.; Dimitriou, P.; Nichols, A. L.

    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. Study of Analytic Statistical Model for Decay of Light and Medium Mass Nuclei in Nuclear Fragmentation

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Wilson, John W.

    1996-01-01

    The angular momentum independent statistical decay model is often applied using a Monte-Carlo simulation to describe the decay of prefragment nuclei in heavy ion reactions. This paper presents an analytical approach to the decay problem of nuclei with mass number less than 60, which is important for galactic cosmic ray (GCR) studies. This decay problem of nuclei with mass number less than 60 incorporates well-known levels of the lightest nuclei (A less than 11) to improve convergence and accuracy. A sensitivity study of the model level density function is used to determine the impact on mass and charge distributions in nuclear fragmentation. This angular momentum independent statistical decay model also describes the momentum and energy distribution of emitted particles (n, p, d, t, h, and a) from a prefragment nucleus.

  13. Sub-Barrier Fusion in the HI + 208Pb Systems and Nuclear Potentials for Cluster Decay

    SciTech Connect

    Sagaidak, R.N.; Tretyakova, S.P.; Khlebnikov, S.V.; Ogloblin, A.A.; Rowley, N.

    2005-11-21

    Near-barrier fusion excitation functions for the 12,14C, 16,18O + 208Pb reactions have been analyzed in the framework of the barrier-passing model using different forms of the nuclear potential and the phenomenology of a fluctuating barrier. The best-fit fusion potentials were used to estimate cluster decay probabilities from the corresponding ground states of Ra and Th, i.e., for the inverse decay process. The analysis supports the 'alpha-decay-like' scenario for carbon and oxygen emission from these nuclei.

  14. Correlation measurements in nuclear {beta}-decay using traps and polarized low energy beams

    SciTech Connect

    Naviliat-Cuncic, Oscar

    2013-05-06

    Precision measurements in nuclear {beta}-decay provide sensitive means to test discrete symmetries in the weak interaction and to determine some of the fundamental constants in semi-leptonic decays, like the coupling of the lightest quarks to charged weak bosons. The main motivation of such measurements is to find deviations from Standard Model predictions as possible indications of new physics. In this contribution I will focus on two topics related to precision measurements in nuclear {beta}-decay: i) the determination of the V{sub ud} element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix from nuclear mirror transitions and ii) the search for exotic scalar or tensor contributions from {beta}{nu} angular correlations. The purpose is to underline the role being played by experimental techniques based on the confinement of radioactive species with atom and ion traps as well as the plans to use low energy polarized beams.

  15. Neutrino propagation in nuclear medium and neutrinoless double-β decay.

    PubMed

    Kovalenko, S; Krivoruchenko, M I; Simkovic, F

    2014-04-11

    We discuss a novel effect in neutrinoless double-β (0νββ) decay related with the fact that its underlying mechanisms take place in the nuclear matter environment. We study the neutrino exchange mechanism and demonstrate the possible impact of nuclear medium via lepton-number-violating (LNV) four-fermion interactions of neutrinos with quarks from a decaying nucleus. The net effect of these interactions is the generation of an effective in-medium Majorana neutrino mass matrix. The enhanced rate of the 0νββ decay can lead to the apparent incompatibility of observations of the 0νββ decay with the value of the neutrino mass determined or restricted by the β-decay and cosmological data. The effective neutrino masses and mixing are calculated for the complete set of the relevant four-fermion neutrino-quark operators. Using experimental data on the 0νββ decay in combination with the β-decay and cosmological data, we evaluate the characteristic scales of these operators: ΛLNV≥2.4  TeV. PMID:24765948

  16. The Nuclear and Particle Physics of Neutrinoless Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Haxton, Wick

    2014-03-01

    Fortuitous properties of nuclei allow us to isolate and study the rare second-order weak process of double beta decay. In particular, the decay channel in which a final state of two electrons and no neutrinos is produced - neutrinoless double beta decay - provides our best test of lepton number conservation and the Majorana mass of the electron neutrino. I will describe the connections between this process and the charge conjugation properties of the neutrino, including the possibility that the presence of both Dirac and Majorana masses accounts for the anomalous scale of neutrino masses. The extraordinary progress made over the past two decades has prepared the way for next-generation experiments that will probe Majorana masses at levels where nonzero rates may be found, given what we now know about neutrino mass splittings. I will describe some of the heroic efforts underway to develop detectors of unprecedented size, radiopurity, depth, and thus sensitivity. Work supported by the Office of Science, US DOE.

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

    SciTech Connect

    Sonzogni, A.A.

    2005-05-24

    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.

  18. Testing JEFF-3.1.1 and ENDF/B-VII.1 Decay and Fission Yield Nuclear Data Libraries with Fission Pulse Neutron Emission and Decay Heat Experiments

    NASA Astrophysics Data System (ADS)

    Cabellos, O.; de Fusco, V.; Diez de la Obra, C. J.; Martinez, J. S.; Gonzalez, E.; Cano-Ott, D.; Alvarez-Velarde, F.

    2014-04-01

    The aim of this work is to test the present status of Evaluated Nuclear Decay and Fission Yield Data Libraries to predict decay heat and delayed neutron emission rate, average neutron energy and neutron delayed spectra after a neutron fission pulse. Calculations are performed with JEFF-3.1.1 and ENDF/B-VII.1, and these are compared with experimental values. An uncertainty propagation assessment of the current nuclear data uncertainties is performed.

  19. Nuclear beta-decay, Atomic Parity Violation, and New Physics

    SciTech Connect

    Michael Ramsey-Musolf

    2000-08-01

    Determinations of vuds with super-allowed Fermi beta-decay in nuclei and of the weak charge of the cesium in atomic parity-violation deviate from the Standard Model predictions by 2 sigma or more. In both cases, the Standard Model over-predicts the magnitudes of the relevant observables. I discuss the implications of these results for R-parity violating (RPV) extensions of the minimal supersymmetric Standard Model. I also explore the possible consequences for RPV supersymmetry of prospective future low-energy electroweak measurements.

  20. Radiotoxicity and decay heat power of spent nuclear fuel of VVER type reactors at long-term storage.

    PubMed

    Bergelson, B R; Gerasimov, A S; Tikhomirov, G V

    2005-01-01

    Radiotoxicity and decay heat power of the spent nuclear fuel of VVER-1000 type reactors are calculated during storage time up to 300,000 y. Decay heat power of radioactive waste (radwaste) determines parameters of the heat removal system for the safe storage of spent nuclear fuel. Radiotoxicity determines the radiological hazard of radwaste after its leakage and penetration into the environment.

  1. Nuclear structure relevant to neutrinoless double beta decay candidate {sup 130}Te and other recent results

    SciTech Connect

    Kay, B. P.

    2013-12-30

    We have undertaken a series of single-nucleon and pair transfer reaction measurements to help constrain calculations of the nuclear matrix elements for neutrinoless double beta decay. In this talk, a short overview of measurements relevant to the {sup 130}Te→{sup 130}Xe system is given. Brief mention is made of other recent and forthcoming results.

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Study of nuclear decays during a solar eclipse: Thule Greenland 2008

    NASA Astrophysics Data System (ADS)

    Javorsek, D.; Brewer, M. C.; Buncher, J. B.; Fischbach, E.; Gruenwald, J. T.; Heim, J.; Hoft, A. W.; Horan, T. J.; Kerford, J. L.; Kohler, M.; Lau, J. J.; Longman, A.; Mattes, J. J.; Mohsinally, T.; Newport, J. R.; Petrelli, M. A.; Stewart, C. A.; Jenkins, J. H.; Lee, R. H.; Morreale, B.; Morris, D. B.; Mudry, R.; O'Keefe, D.; Terry, B.; Silver, M. A.; Sturrock, P. A.

    2012-11-01

    Recent efforts to determine the cause of anomalous experimental nuclear decay fluctuations suggests a possible solar influence. Here we report on the results from several nuclear decay experiments performed at Thule Air Base in Greenland during the solar eclipse on 1 August 2008. Thule was ideal for this experiment due to its proximity to the magnetic north pole which amplified changes in the charged particle flux and provided relatively stabilized conditions for nearly all environmental factors. An exhaustive list of relevant factors were monitored during the eclipse to help rule out possible systematic effects in the event of unexpected results. We included measurements of temperature, pressure, and humidity as well as power supply outputs, neutron count rates, and the Earth's local electric and magnetic fields. Nuclear decay measurements of 14C, 90Sr, 99Tc, 210Bi, 234Pa, and 241Am were made using Geiger-Müller (GM) ionization chambers. Although our data exhibit no evidence for a statistically significant change in the decay rate of any nuclide measured during the 1 August 2008 solar eclipse, small anomalies remain to be understood.

  4. Shape and pairing fluctuation effects on neutrinoless double beta decay nuclear matrix elements.

    PubMed

    López Vaquero, Nuria; Rodríguez, Tomás R; Egido, J Luis

    2013-10-01

    Nuclear matrix elements (NME) for the most promising candidates to detect neutrinoless double beta decay have been computed with energy density functional methods including deformation and pairing fluctuations explicitly on the same footing. The method preserves particle number and angular momentum symmetries and can be applied to any decay without additional fine tunings. The finite range density dependent Gogny force is used in the calculations. An increase of 10%-40% in the NME with respect to the ones found without the inclusion of pairing fluctuations is obtained, reducing the predicted half-lives of these isotopes.

  5. Search for rare nuclear decays with HPGe detectors at the STELLA facility of the LNGS

    SciTech Connect

    Belli, P.; Di Marco, A.; Bernabei, R.; D'Angelo, S.; Cappella, F.; D'Angelo, A.; Incicchitti, A.; Cerulli, R.; Di Vacri, M. L.; Laubenstein, M.; Nisi, S.; Danevich, F. A.; Kobychev, V. V.; Poda, D. V.; Tretyak, V. I.; Kovtun, G. P.; Kovtun, N. G.; Shcherban, A. P.; Solopikhin, D. A.; Polischuk, O. G.; and others

    2013-12-30

    Results on the search for rare nuclear decays with the ultra low background facility STELLA at the LNGS using gamma ray spectrometry are presented. In particular, the best T{sub 1/2} limits were obtained for double beta processes in {sup 96}Ru and {sup 104}Ru. Several isotopes, which potentially decay through different 2β channels, including also possible resonant double electron captures, were investigated for the first time ({sup 156}Dy, {sup 158}Dy, {sup 184}Os, {sup 192}Os, {sup 190}Pt, {sup 198}Pt). Search for resonant absorption of solar {sup 7}Li axions in a LiF crystal gave the best limit for the mass of {sup 7}Li axions (< 8.6 keV). Rare alpha decay of {sup 190}Pt to the first excited level of {sup 186}Os(E{sub exc} = 137.2keV) was observed for the first time.

  6. Impact of nuclear dynamics on interatomic Coulombic decay in a He dimer

    SciTech Connect

    Sisourat, Nicolas; Kryzhevoi, Nikolai V.; Cederbaum, Lorenz S.; Kolorenc, Premysl; Scheit, Simona

    2010-11-15

    After simultaneous ionization and excitation of one helium atom within the giant weakly bound helium dimer, the excited ion can relax via interatomic Coulombic decay (ICD) and the excess energy is transferred to ionize the neighboring helium atom. We showed [Sisourat et al. Nature Phys. 6, 508 (2010)] that the distributions of the kinetic energy released by the two ions reflect the nodal structures of the ICD-involved vibrational wave functions. We also demonstrated that energy transfer via ICD between the two helium atoms can take place over more than 14 A. We report here a more detailed analysis of the ICD process and of the impact of the nuclear dynamics on the electronic decay. Nonadiabatic effects during the ICD process and the accuracy of the potential energy curve of helium dimer and of the computed decay rates are also investigated.

  7. Preliminary Results from Nuclear Decay Experiments Performed During the Solar Eclipse of August 1, 2008

    SciTech Connect

    Javorsek, D. II; Kerford, J. L.; Stewart, C. A.; Hoft, A. W.; Horan, T. J.; Buncher, J. B.; Fischbach, E.; Gruenwald, J. T.; Heim, J.; Kohler, M.; Longman, A.; Mattes, J. J.; Mohsinally, T.; Newport, J. R.; Jenkins, J. H.; Lee, R. H.; Morreale, B.; Morris, D. B.; O'Keefe, D.; Terry, B.

    2010-08-04

    Recent developments in efforts to determine the cause of anomalous experimental nuclear decay fluctuations suggest a possible solar influence. Here we report on the preliminary results from several nuclear decay experiments performed at Thule Air Base in Greenland during the Solar Eclipse that took place on 1 August 2008. Because of the high northern latitude and time of year, the Sun never set and thereby provided relatively stabilized conditions for nearly all environmental factors. An exhaustive list of relevant factors were monitored during the eclipse to help rule out possible systematic effects due to external influences. In addition to the normal temperature, pressure, humidity, and cloud cover associated with the outside ambient observations, we included similar measurements within the laboratory along with monitoring of the power supply output, local neutron count rates, and the Earth's local magnetic and electric fields.

  8. Calculation Of Two Neutrino Double Beta Decay Nuclear Matrix Elements For 128,130Te

    SciTech Connect

    Uenlue, S.; Salamov, D. I.; Babacan, T.; Kuecuekbursa, A.

    2006-04-26

    Based on Pyatov-Salamov method, spin-isospin (Gamow-Teller) effective interaction strength parameter has been found self-consistently. Then, the problem has been solved within the framework of QRPA. Gamow-Teller matrix elements for both {beta}- and {beta}+ transitions and two neutrino double beta decay nuclear matrix elements have been calculated for 128,130Te{yields}128,130Xe transitions. The obtained results have been compared with the corresponding experimental data and other theoretical results.

  9. THE AIMS AND ACTIVITIES OF THE INTERNATIONAL NETWORK OF NUCLEAR STRUCTURE AND DECAY DATA EVALUATORS.

    SciTech Connect

    NICHOLS,A.L.; TULI, J.K.

    2007-04-22

    International Network of Nuclear Structure and Decay Data (NSDD) Evaluators consists of a number of evaluation groups and data service centers in several countries that appreciate the merits of working together to maintain and ensure the quality and comprehensive content of the ENSDF database (Evaluated Nuclear Structure Data File). Biennial meetings of the network are held under the auspices of the International Atomic Energy Agency (IAEA) to assign evaluation responsibilities, monitor progress, discuss improvements and emerging difficulties, and agree on actions to be undertaken by individual members. The evaluated data and bibliographic details are made available to users via various media, such as the journals ''Nuclear Physics A'' and ''Nuclear Data Sheets'', the World Wide Web, on CD-ROM, wall charts of the nuclides and ''Nuclear Wallet Cards''. While the ENSDF master database is maintained by the US National Nuclear Data Center at the Brookhaven National Laboratory, these data are also available from other nuclear data centers including the IAEA Nuclear Data Section. The Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy, in cooperation with the IAEA, organizes workshops on NSDD at regular intervals. The primary aims of these particular workshops are to provide hands-on training in the data evaluation processes, and to encourage new evaluators to participate in NSDD activities. The technical contents of these NSDD workshops are described, along with the rationale for the inclusion of various topics.

  10. Nuclear reaction uncertainties, massive gravitino decays and the cosmological lithium problem

    SciTech Connect

    Cyburt, Richard H.; Ellis, John; Fields, Brian D.; Luo, Feng; Olive, Keith A.; Spanos, Vassilis C. E-mail: john.ellis@cern.ch E-mail: fluo@physics.umn.edu E-mail: spanos@physics.umn.edu

    2010-10-01

    We consider the effects of uncertainties in nuclear reaction rates on the cosmological constraints on the decays of unstable particles during or after Big-Bang nucleosynthesis (BBN). We identify the nuclear reactions due to non-thermal hadrons that are the most important in perturbing standard BBN, then quantify the uncertainties in these reactions and in the resulting light-element abundances. These results also indicate the key nuclear processes for which improved cross section data would allow different light-element abundances to be determined more accurately, thereby making possible more precise probes of BBN and evaluations of the cosmological constraints on unstable particles. Applying this analysis to models with unstable gravitinos decaying into neutralinos, we calculate the likelihood function for the light-element abundances measured currently, taking into account the current experimental errors in the determinations of the relevant nuclear reaction rates. We find a region of the gravitino mass and abundance in which the abundances of deuterium, {sup 4}He and {sup 7}Li may be fit with χ{sup 2} = 5.5, compared with χ{sup 2} = 31.7 if the effects of gravitino decays are unimportant. The best-fit solution is improved to χ{sup 2} ∼ 2.0 when the lithium abundance is taken from globular cluster data. Some such re-evaluation of the observed light-element abundances and/or nuclear reaction rates would be needed if this region of gravitino parameters is to provide a complete solution to the cosmological {sup 7}Li problem.

  11. New limits for the 2 νββ decay of 96Zr to excited nuclear states of 96Mo

    NASA Astrophysics Data System (ADS)

    Finch, Sean; Tornow, Werner

    2015-10-01

    The final results from our search for the 2 νββ decay of 96Zr to excited 0+ and 2+ states of 96Mo are presented. Such measurements provide valuable test cases for 2 νββ -decay nuclear matrix element calculations, which in turn are used to tune 0 νββ -decay nuclear matrix element calculations. After undergoing double- β decay to an excited state, the excited daughter nucleus decays to the ground state, emitting two coincident γ rays. These two γ rays are detected in coincidence by two HPGe detectors sandwiching the 96Zr sample, with a NaI veto in anti-coincidence. This experimental apparatus, located at the Kimballton Underground Research Facility (KURF), has previously measured the 2 νββ decay of 100Mo and 150Nd to excited nuclear states. Experimental limits on the T1 / 2 and corresponding nuclear matrix element are presented for each of these decays. As a byproduct of this experiment, limits were also set on the single- β decay of 96Zr. Supported by DOE Grant: DE-FG02-97ER41033.

  12. Radiotoxicity and decay heat power of spent nuclear fuel of VVER type reactors at long-term storage.

    PubMed

    Bergelson, B R; Gerasimov, A S; Tikhomirov, G V

    2005-01-01

    Radiotoxicity and decay heat power of the spent nuclear fuel of VVER-1000 type reactors are calculated during storage time up to 300,000 y. Decay heat power of radioactive waste (radwaste) determines parameters of the heat removal system for the safe storage of spent nuclear fuel. Radiotoxicity determines the radiological hazard of radwaste after its leakage and penetration into the environment. PMID:16381764

  13. Contribution of Neutron Beta Decay to Radiation Belt Pumping from High Altitude Nuclear Explosion

    SciTech Connect

    Marrs, R

    2002-11-13

    In 1962, several satellites were lost following high altitude nuclear tests by the United States and the Soviet Union. These satellite failures were caused by energetic electrons injected into the earth's radiation belts from the beta decay of bomb produced fission fragments and neutrons. It has been 40 years since the last high altitude nuclear test; there are now many more satellites in orbit, and it is important to understand their vulnerability to radiation belt pumping from nuclear explosions at high altitude or in space. This report presents the results of a calculation of the contribution of neutron beta decay to artificial belt pumping. For most high altitude nuclear explosions, neutrons are expected to make a smaller contribution than fission products to the total trapped electron inventory, and their contribution is usually neglected. However, the neutron contribution may dominate in cases where the fission product contribution is suppressed due to the altitude or geomagnetic latitude of the nuclear explosion, and for regions of the radiation belts with field lines far from the detonation point. In any case, an accurate model of belt pumping from high altitude nuclear explosions, and a self-consistent explanation of the 1962 data, require inclusion of the neutron contribution. One recent analysis of satellite measurements of electron flux from the 1962 tests found that a better fit to the data is obtained if the neutron contribution to the trapped electron inventory was larger than that of the fission products [l]. Belt pumping from high altitude nuclear explosions is a complicated process. Fission fragments are dispersed as part of the ionized bomb debris, which is constrained and guided by the earth's magnetic field. Those fission products that beta decay before being lost to the earth's atmosphere can contribute trapped energetic electrons to the earth's radiation belts. There has been a large effort to develop computer models for the contribution of

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

    NASA Astrophysics Data System (ADS)

    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.

  15. Uncertainties in nuclear transition matrix elements of neutrinoless ββ decay

    SciTech Connect

    Rath, P. K.

    2013-12-30

    To estimate the uncertainties associated with the nuclear transition matrix elements M{sup (K)} (K=0ν/0N) for the 0{sup +} → 0{sup +} transitions of electron and positron emitting modes of the neutrinoless ββ decay, a statistical analysis has been performed by calculating sets of eight (twelve) different nuclear transition matrix elements M{sup (K)} in the PHFB model by employing four different parameterizations of a Hamiltonian with pairing plus multipolar effective two-body interaction and two (three) different parameterizations of Jastrow short range correlations. The averages in conjunction with their standard deviations provide an estimate of the uncertainties associated the nuclear transition matrix elements M{sup (K)} calculated within the PHFB model, the maximum of which turn out to be 13% and 19% owing to the exchange of light and heavy Majorana neutrinos, respectively.

  16. Theoretical uncertainties in the nuclear matrix elements of neutrinoless double beta decay: The transition operator

    SciTech Connect

    Menéndez, Javier

    2013-12-30

    We explore the theoretical uncertainties related to the transition operator of neutrinoless double-beta (0νββ) decay. The transition operator used in standard calculations is a product of one-body currents, that can be obtained phenomenologically as in Tomoda [1] or Šimkovic et al. [2]. However, corrections to the operator are hard to obtain in the phenomenological approach. Instead, we calculate the 0νββ decay operator in the framework of chiral effective theory (EFT), which gives a systematic order-by-order expansion of the transition currents. At leading orders in chiral EFT we reproduce the standard one-body currents of Refs. [1] and [2]. Corrections appear as two-body (2b) currents predicted by chiral EFT. We compute the effects of the leading 2b currents to the nuclear matrix elements of 0νββ decay for several transition candidates. The 2b current contributions are related to the quenching of Gamow-Teller transitions found in nuclear structure calculations.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    Marini, P.; Zheng, H.; Boisjoli, M.; Verde, G.; Chbihi, A.; Napolitani, P.; Ademard, G.; Augey, L.; Bhattacharya, C.; Borderie, B.; Bougault, R.; Frankland, J. D.; Fable, Q.; Galichet, E.; Gruyer, D.; Kundu, S.; La Commara, M.; Lombardo, I.; Lopez, O.; Mukherjee, G.; Parlog, M.; Rivet, M. F.; Rosato, E.; Roy, R.; Spadaccini, G.; Vigilante, M.; Wigg, P. C.; Bonasera, A.

    2016-05-01

    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.

  19. Passive decay heat removal system for water-cooled nuclear reactors

    DOEpatents

    Forsberg, Charles W.

    1991-01-01

    A passive decay-heat removal system for a water-cooled nuclear reactor employs a closed heat transfer loop having heat-exchanging coils inside an open-topped, insulated box located inside the reactor vessel, below its normal water level, in communication with a condenser located outside of containment and exposed to the atmosphere. The heat transfer loop is located such that the evaporator is in a position where, when the water level drops in the reactor, it will become exposed to steam. Vapor produced in the evaporator passes upward to the condenser above the normal water level. In operation, condensation in the condenser removes heat from the system, and the condensed liquid is returned to the evaporator. The system is disposed such that during normal reactor operations where the water level is at its usual position, very little heat will be removed from the system, but during emergency, low water level conditions, substantial amounts of decay heat will be removed.

  20. Time-Dependent Nuclear Decay Parameters: New Evidence for New Forces?

    NASA Astrophysics Data System (ADS)

    Fischbach, E.; Buncher, J. B.; Gruenwald, J. T.; Jenkins, J. H.; Krause, D. E.; Mattes, J. J.; Newport, J. R.

    2009-07-01

    This paper presents an overview of recent research dealing with the question of whether nuclear decay rates (or half-lives) are time-independent constants of nature, as opposed to being parameters which can be altered by an external perturbation. If the latter is the case, this may imply the existence of some new interaction(s) which would be responsible for any observed time variation. Interest in this question has been renewed recently by evidence for a correlation between nuclear decay rates and Earth-Sun distance, and by the observation of a dip in the decay rate for 54Mn coincident in time with the solar flare of 2006 December 13. We discuss these observations in detail, along with other hints in the literature for time-varying decay parameters, in the framework of a general phenomenology that we develop. One consequence of this phenomenology is that it is possible for different experimental groups to infer discrepant (yet technically correct) results for a half-life depending on where and how their data were taken and analyzed. A considerable amount of attention is devoted to possible mechanisms which might give rise to the reported effects, including fluctuations in the flux of solar neutrinos, and possible variations in the magnitudes of fundamental parameters, such as the fine structure constant and the electron-to-proton mass ratio. We also discuss ongoing and future experiments, along with some implications of our work for cancer treatments, 14C dating, and for the possibility of detecting the relic neutrino background.

  1. Degeneracies of particle and nuclear physics uncertainties in neutrinoless β β decay

    NASA Astrophysics Data System (ADS)

    Lisi, E.; Rotunno, A. M.; Šimkovic, F.

    2015-11-01

    Theoretical estimates for the half-life of neutrinoless double beta decay (0 ν β β ) in candidate nuclei are affected by both particle and nuclear physics uncertainties, which may complicate the interpretation of decay signals or limits. We study such uncertainties and their degeneracies in the following context: three 0 ν β β nuclei of great interest for large-scale experiments (Ge 76 , Te 130 , Xe 136 ), two representative particle physics mechanisms (light and heavy Majorana neutrino exchange), and a large set of nuclear matrix elements (NME), computed within the quasiparticle random phase approximation (QRPA). It turns out that the main theoretical uncertainties, associated with the effective axial coupling gA and with the nucleon-nucleon potential, can be parametrized in terms of NME rescaling factors, up to small residuals. From this parametrization, the following QRPA features emerge: (1) the NME dependence on gA is milder than quadratic, (2) in each of the two mechanisms, the relevant lepton number violating parameter is largely degenerate with the NME rescaling factors, and (3) the light and heavy neutrino exchange mechanisms are basically degenerate in the above three nuclei. We comment on the challenging theoretical and experimental improvements required to reduce such particle and nuclear physics uncertainties and their degeneracies.

  2. Nuclear-Structure Data Relevant to Neutinoless-Double-Beta-Decay Matrix Elements

    NASA Astrophysics Data System (ADS)

    Kay, Benjamin

    2015-10-01

    An observation of neutrinoless double beta decay is one of the most exciting prospects in contemporary physics. It follows that calculations of the nuclear matrix elements for this process are of high priority. The change in the wave functions between the initial and final states of the neutrinoless-double-beta-decay candidates 76Ge-->76Se, 100Mo-->100Ru, 130Te-->130Xe, and 136Xe-->136Ba have been studied with transfer reactions. The data are focused on the change in the occupancies of the valence orbitals in the ground states as two neutrons decay into two protons. The results set a strict constraint on any theoretical calculations describing this rearrangement and thus on the magnitude of the nuclear matrix elements for this process, which currently exhibit uncertainties at the factor of 2-4 level. Prior to these measurements there were limited experimental data were available A = 76 and 100 systems, and very limited data for the A = 130 and 136 systems, in a large part due to the gaseous Xe isotopes involved. The uncertainties on most of these data are estimated to range from 0.1-0.3 nucleons. The program started with the A = 76 system, with subsequent calculations, modified to reproduce the experimental occupancies, exhibiting a significant reduction in the discrepancy between various models. New data are available for the A = 100 , 130, and 136 systems. I review the program, making detailed comparisons between the latest theoretical calculations and the experimental data where available. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Contract Number DE-AC02-06CH11357.

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

    SciTech Connect

    Terasaki, J.

    2015-10-28

    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 {sup 150}Nd→{sup 150}Sm using these two new ideas, and their implication is discussed.

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

    SciTech Connect

    Nichols, Alan L.; Dimitrious, P.; Kondev, F. G.; Ricard-McCutchan, E.

    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.

  5. Systematic and Statistical Errors Associated with Nuclear Decay Constant Measurements Using the Counting Technique

    NASA Astrophysics Data System (ADS)

    Koltick, David; Wang, Haoyu; Liu, Shih-Chieh; Heim, Jordan; Nistor, Jonathan

    2016-03-01

    Typical nuclear decay constants are measured at the accuracy level of 10-2. There are numerous reasons: tests of unconventional theories, dating of materials, and long term inventory evolution which require decay constants accuracy at a level of 10-4 to 10-5. The statistical and systematic errors associated with precision measurements of decays using the counting technique are presented. Precision requires high count rates, which introduces time dependent dead time and pile-up corrections. An approach to overcome these issues is presented by continuous recording of the detector current. Other systematic corrections include, the time dependent dead time due to background radiation, control of target motion and radiation flight path variation due to environmental conditions, and the time dependent effects caused by scattered events are presented. The incorporation of blind experimental techniques can help make measurement independent of past results. A spectrometer design and data analysis is reviewed that can accomplish these goals. The author would like to thank TechSource, Inc. and Advanced Physics Technologies, LLC. for their support in this work.

  6. Superallowed Beta Decay Studies at TRIUMF --- Nuclear Structure and Fundamental Symmetries

    NASA Astrophysics Data System (ADS)

    Zganjar, E. F.; Achtzehn, T.; Albers, D.; Andreoiu, C.; Andreyev, A. N.; Austin, R. A. E.; Ball, G. C.; Behr, J. A.; Biosvert, G. C.; Bricault, P.; Bishop, S.; Chakrawarthy, R. S.; Churchman, R.; Cross, D.; Cunningham, E.; D'Auria, J. M.; Dombsky, M.; Finlay, P.; Garrett, P. E.; Grinyer, G. F.; Hackman, G.; Hanemaayer, V.; Hardy, J. C.; Hodgson, D. F.; Hyland, B.; Iacob, V.; Klages, P.; Koopmans, K. A.; Kulp, W. D.; Lassen, J.; Lavoie, J. P.; Leslie, J. R.; Linder, T.; MacDonald, J. A.; Mak, H.-B.; Melconian, D.; Morton, A. C.; Ormand, W. E.; Osborne, C. J.; Pearson, C. J.; Pearson, M. R.; Phillips, A. A.; Piechaczek, A.; Ressler, J.; Sarazin, F.; Savard, G.; Schumaker, M. A.; Scraggs, H. C.; Svensson, C. E.; Valiente-Dobon, J. J.; Towner, I. S.; Waddington, J. C.; Walker, P. M.; Wendt, K.; Wood, J. L.

    2007-04-01

    Precision measurement of the beta -decay half-life, Q-value, and branching ratio between nuclear analog states of Jpi = 0+ and T=1 can provide critical and fundamental tests of the Standard Model's description of electroweak interactions. A program has been initiated at TRIUMF-ISAC to measure the ft values of these superallowed beta transitions. Two Tz = 0, A > 60 cases, 74Rb and 62Ga, are presented. These are particularly relevant because they can provide critical tests of the calculated nuclear structure and isospin-symmetry breaking corrections that are predicted to be larger for heavier nuclei, and because they demonstrate the advance in the experimental precision on ft at TRIUMF-ISAC from 0.26% for 74Rb in 2002 to 0.05% for 62Ga in 2006. The high precision world data on experimental ft and corrected Ft values are discussed and shown to be consistent with CVC at the 10-4 level, yielding an average Ft = 3073.70(74) s. This Ft leads to Vud = 0.9737(4) for the up-down element of the Standard Model's CKM matrix. With this value and the Particle Data Group's 2006 values for Vus and Vub, the unitarity condition for the CKM matrix is met. Additional measurements and calculations are needed, however, to reduce the uncertainties in that evaluation. That objective is the focus of the continuing program on superallowed-beta decay at TRIUMF-ISAC.

  7. Precise test of the unitarity of the CKM matrix via superallowed nuclear beta decay

    NASA Astrophysics Data System (ADS)

    Park, Hyo-In

    2016-03-01

    Superallowed 0+ --> 0+ nuclear beta decay between isospin T = 1 analogue states is a sensitive probe for studying the fundamental properties of the weak interaction. Today, the most precise measurements of the decay strengths (or ft values) of fourteen superallowed transitions, ranging from 10C to 74Rb, provide a direct determination of the vector coupling constant GV, and lead to the most precise value of Vud, the up-down quark-mixing element of the Cabbibo-Kobayashi-Maskawa (CKM) matrix. When Vud is combined with the other top-row elements, Vus and Vub, the sum of squares of the top-row elements of the CKM matrix satisfies the unitarity condition at the level of +/-0.06%. The impact of this result on searches for new physics beyond the Standard Model motivates further work to improve even further the precision of the CKM-matrix unitarity sum. Our current focus is on measurements to constrain the uncertainty in calculations of the isospin-symmetry-breaking corrections needed to determine Vud from the experimental data. This can be achieved with high-precision comparisons of the ft values from four pairs of accessible mirror superallowed decays with A <= 42 . This presentation reports our results for the mass-38 pair, 38Ca --> 38mK and 38mK --> 38Ar, and our progress on measuring 42Ti decay. The measured ratio of the mirror ft values for A = 38 agrees well with the corrections currently used, and points the way to even tighter constraints on the unitarity of the CKM matrix. If the three mirror pairs, with A = 26 , A = 34 and A = 42 confirm and strengthen our present conclusion, it will become possible to shrink the systematic uncertainty on Vud, reduce the uncertainty on the CKM-matrix unitarity sum, and further constrain the scope for possible extensions to the Standard Model.

  8. Experimental studies of nuclear matrix elements for neutrino-less ββ decays

    SciTech Connect

    Ejiri, H.

    2013-12-30

    Nuclear matrix elements M{sup 0ν} for neutrino less double beta decays (0νββ) are crucial for neutrino studies in 0νββ experiments. The neutrino mass to be studied is sensitive to M{sup 0ν}, while theoretical calculations for M{sup 0ν} are hard. Thus experimental studies of nuclear structures and single β matrix elements M{sub β} associated with 0νββ are useful to confirm and help the theoretical calculations. This reports briefly experimental methods and recent charge exchange reaction studies for M{sub β}. The single β elements for M{sup ±}(2{sup −}) associated with M{sup 0ν}(2{sup −}), which is the major component of M{sup 0ν}, are found to be reduced (quenched) much by the spin isospin correlation and the nuclear medium (non-nucleonic isobar) effect. The present result suggests that the spin isospin components of M{sup 0ν} is fairly reduced (quenched)

  9. The evaluation of half-lives and other decay data used in nuclear astrophysics and cosmochronology

    SciTech Connect

    Chechev, V. P.

    2011-12-15

    The current status of some decay data used in nuclear astrophysics and cosmochronology is presented. The half-life of {sup 79}Se has been evaluated as 3.6(3) Multiplication-Sign 10{sup 5} yr. The total energy of non-neutrino radiation released in act of {sup 37}Ar decay has been obtained being 2.709 (16) keV per disintegration. The recommended half-life values of the long-lived radionuclides (T{sub 1/2} Greater-Than-Or-Equivalent-To 10{sup 6} yr) of {sup 26}Al, {sup 40}K, {sup 53}Mn, {sup 60}Fe, {sup 87}Rb, {sup 93}Zr, {sup 98}Tc, {sup 107}Pd, {sup 129}I, {sup 135}Cs, {sup 146}Sm, {sup 176}Lu, {sup 182}Hf, {sup 187}Re, {sup 205}Pb, {sup 232}Th, {sup 235}U, {sup 238}U, {sup 244}Pu, and {sup 247}Cm are given based on the evaluations published until 2010.

  10. Nuclear β --decay half-lives for {fp} and {fpg} shell nuclei

    NASA Astrophysics Data System (ADS)

    Kumar, Vikas; Srivastava, P. C.; Li, Hantao

    2016-10-01

    In the present work we calculate the allowed {β }--decay half-lives of nuclei with Z=20-30 and N ≤slant 50 systematically under the framework of the nuclear shell model. A recent study shows that some nuclei in this region belong to the island of inversion. We perform calculation for fp shell nuclei using the KB3G effective interaction. In the case of Ni, Cu, and Zn, we used the JUN45 effective interaction. Theoretical results of Q values, half-lives, excitation energies, logft values, and branching fractions are discussed and compared with the experimental data. In the Ni region, we also compared our calculated results with recent experimental data (Xu et al 2014 Phys. Rev. Lett. 113 032505). The present results agree with the experimental data of half-lives in comparison to QRPA.

  11. Spin dipole nuclear matrix elements for double beta decay nuclei by charge-exchange reactions

    NASA Astrophysics Data System (ADS)

    Ejiri, H.; Frekers, D.

    2016-11-01

    Spin dipole (SD) strengths for double beta-decay (DBD) nuclei were studied experimentally for the first time by using measured cross sections of (3He, t) charge-exchange reactions (CERs). Then SD nuclear matrix elements (NMEs) {M}α ({{SD}}) for low-lying 2‑ states were derived from the experimental SD strengths by referring to the experimental α = GT (Gamow–Teller) and α = F (Fermi) strengths. They are consistent with the empirical NMEs M({{SD}}) based on the quasi-particle model with the empirical effective SD coupling constant. The CERs are used to evaluate the SD NME, which is associated with one of the major components of the neutrino-less DBD NME.

  12. Exotic nuclear decay of /sup 223/Ra by emission of /sup 14/C nuclei

    SciTech Connect

    Gales, S.; Hourani, E.; Hussonnois, M.; Schapira, J.P.; Stab, L.; Vergnes, M.

    1984-08-20

    The exotic nuclear decay of /sup 223/Ra by emission of /sup 14/C nuclei has been investigated by use of an intense radioactive /sup 227/Ac source and a magnetic spectrometer with a large solid angle. After a run of 5 d, a group of eleven events was observed at the expected location of /sup 14/C in a ..delta..E-E telescope calibrated with a /sup 14/C beam. A branching ratio of (5.5 +- 2.0) x 10/sup -10/ was measured for the emission of /sup 14/C nuclei relative to ..cap alpha.. particles from /sup 223/Ra in agreement with the previously reported ratio of (8.5 +- 2.5) x 10/sup -10/. .AE

  13. Disordered nuclear pasta, magnetic field decay, and crust cooling in neutron stars

    NASA Astrophysics Data System (ADS)

    Horowitz, C. J.; Berry, D. K.; Briggs, C. M.; Caplan, M. E.; Cumming, A.; Schneider, A. S.

    2015-04-01

    Nuclear pasta, with non-spherical shapes, is expected near the base of the crust in neutron stars. Large scale molecular dynamics simulations of pasta show long lived topological defects that could increase electron scattering and reduce both the thermal and electrical conductivities. We model a possible low conductivity pasta layer by increasing an impurity parameter Qimp. Predictions of light curves for the low mass X-ray binary MXB 1659-29, assuming a large Qimp, find continued late time cooling that is consistent with Chandra observations. The electrical and thermal conductivities are likely related. Therefore observations of late time crust cooling can provide insight on the electrical conductivity and the possible decay of neutron star magnetic fields (assuming these are supported by currents in the crust). This research was supported in part by DOE Grants DE-FG02-87ER40365 (Indiana University) and DE-SC0008808 (NUCLEI SciDAC Collaboration).

  14. Disordered Nuclear Pasta, Magnetic Field Decay, and Crust Cooling in Neutron Stars

    NASA Astrophysics Data System (ADS)

    Horowitz, C. J.; Berry, D. K.; Briggs, C. M.; Caplan, M. E.; Cumming, A.; Schneider, A. S.

    2015-01-01

    Nuclear pasta, with nonspherical shapes, is expected near the base of the crust in neutron stars. Large-scale molecular dynamics simulations of pasta show long lived topological defects that could increase electron scattering and reduce both the thermal and electrical conductivities. We model a possible low-conductivity pasta layer by increasing an impurity parameter Qimp . Predictions of light curves for the low-mass x-ray binary MXB 1659-29, assuming a large Qimp, find continued late time cooling that is consistent with Chandra observations. The electrical and thermal conductivities are likely related. Therefore, observations of late time crust cooling can provide insight on the electrical conductivity and the possible decay of neutron star magnetic fields (assuming these are supported by currents in the crust).

  15. Disordered nuclear pasta, magnetic field decay, and crust cooling in neutron stars.

    PubMed

    Horowitz, C J; Berry, D K; Briggs, C M; Caplan, M E; Cumming, A; Schneider, A S

    2015-01-23

    Nuclear pasta, with nonspherical shapes, is expected near the base of the crust in neutron stars. Large-scale molecular dynamics simulations of pasta show long lived topological defects that could increase electron scattering and reduce both the thermal and electrical conductivities. We model a possible low-conductivity pasta layer by increasing an impurity parameter Q_{imp}. Predictions of light curves for the low-mass x-ray binary MXB 1659-29, assuming a large Q_{imp}, find continued late time cooling that is consistent with Chandra observations. The electrical and thermal conductivities are likely related. Therefore, observations of late time crust cooling can provide insight on the electrical conductivity and the possible decay of neutron star magnetic fields (assuming these are supported by currents in the crust).

  16. Nuclear matrix elements for 0{nu}{beta}{beta} decay with improved short-range correlations

    SciTech Connect

    Kortelainen, M.; Suhonen, J.

    2007-10-12

    Nuclear matrix elements for the neutrinoless double beta minus (0{nu}{beta}{sup -}{beta}{sup -}) decays of all interesting (nearly) spherical nuclei are calculated for the light-neutrino exchange mechanism by using the proton-neutron quasiparticle random-phase approximation (pnQRPA) with a realistic nucleon-nucleon force. The finite size of a nucleon, the higher-order terms of nucleonic weak currents, and the nucleon-nucleon short-range correlations (s.r.c) are taken into account. The s.r.c. are computed by the use of the unitary correlation operator method (UCOM), superior to the traditional Jastrow method. The UCOM computed matrix elements turn out to be considerably larger than the Jastrow computed ones.

  17. Channel-Coupling Contribution to the Widths of Decay Nuclear States and to Their Wave Functions

    SciTech Connect

    Kadmensky, S.G.

    2004-12-01

    By using the formalism of the quantum theory of fission, the amplitudes of partial decay widths and the asymptotic behavior of the wave function for a decaying nucleus are found with allowance for open-decay-channel coupling not only for fission, but also for the binary decays of nuclei through protonic, alpha-particle, cluster, and other channels.

  18. Impact of the new nuclear decay data of ICRP publication 107 on inhalation dose coefficients for workers

    SciTech Connect

    Manabe, K.; Endo, Akira; Eckerman, Keith F

    2010-03-01

    The impact a revision of nuclear decay data had on dose coefficients was studied using data newly published in ICRP Publication 107 (ICRP 107) and existing data from ICRP Publication 38 (ICRP 38). Committed effective dose coefficients for occupational inhalation of radionuclides were calculated using two sets of decay data with the dose and risk calculation software DCAL for 90 elements, 774 nuclides and 1572 cases. The dose coefficients based on ICRP 107 increased by over 10 % compared with those based on ICRP 38 in 98 cases, and decreased by over 10 % in 54 cases. It was found that the differences in dose coefficients mainly originated from changes in the radiation energy emitted per nuclear transformation. In addition, revisions of the half-lives, radiation types and decay modes also resulted in changes in the dose coefficients.

  19. Impact of the new nuclear decay data of ICRP publication 107 on inhalation dose coefficients for workers.

    PubMed

    Manabe, K; Endo, A; Eckerman, K F

    2010-03-01

    The impact a revision of nuclear decay data had on dose coefficients was studied using data newly published in ICRP Publication 107 (ICRP 107) and existing data from ICRP Publication 38 (ICRP 38). Committed effective dose coefficients for occupational inhalation of radionuclides were calculated using two sets of decay data with the dose and risk calculation software DCAL for 90 elements, 774 nuclides and 1572 cases. The dose coefficients based on ICRP 107 increased by over 10 % compared with those based on ICRP 38 in 98 cases, and decreased by over 10 % in 54 cases. It was found that the differences in dose coefficients mainly originated from changes in the radiation energy emitted per nuclear transformation. In addition, revisions of the half-lives, radiation types and decay modes also resulted in changes in the dose coefficients.

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

    NASA Astrophysics Data System (ADS)

    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 < 10-100 days), the concentration should be different for meteorites hitting the Earth on the incoming vs. outgoing part of their orbit. However, the current data base of very short-lived radionuclides in freshly fallen meteorites is far from sufficient to deduce solid constraints. Constraints on the age of the Earth and the oldest meteorite phases obtained by the U-Pb dating technique give no hints for radially variable decay rates of the α-decaying nuclides 235U or 238U. Similarly, some of the oldest phases in meteorites have U-Pb ages whose differences agree almost perfectly with respective age differences obtained with "short-lived" radionuclides present in the early solar system, again indicating no variability of uranium decay rates in different meteorite parent bodies in the asteroid belt

  1. T-odd correlations in Z{sup 0} decay into three jets and in nuclear beta decay

    SciTech Connect

    Conzett, H.E.

    1997-05-01

    The naive time-reversal (T{sub N}) operation reverses momenta and spins {ital without} the interchange of initial and final states that is included in the time-reversal (T) operation. In a recent report of the measurement of the transverse analyzing-power A{sub y} in the three-jet decay of polarized Z{sup 0} bosons, A{sub y} was considered to be a T{sub N}-odd, but not T-odd, observable. This leads to an incorrect conclusion. In this paper it is shown that the T{sub N} operation is an incomplete substitute for the combined conditions that T symmetry and hermiticity impose on the transition amplitudes in first-order electromagnetic or weak processes. Other misconceptions concerning relationships between T-odd operators and (so called) T-odd observables are discussed. {copyright} {ital 1997 American Institute of Physics.}

  2. T-odd correlations in Z{sup 0} decay into three jets and in nuclear beta decay

    SciTech Connect

    Conzett, H. E.

    1997-05-20

    The naive time-reversal (T{sub N}) operation reverses momenta and spins without the interchange of initial and final states that is included in the time-reversal (T) operation. In a recent report of the measurement of the transverse analyzing-power A{sub y} in the three-jet decay of polarized Z{sup 0} bosons, A{sub y} was considered to be a T{sub N}-odd, but not T-odd, observable. This leads to an incorrect conclusion. In this paper it is shown that the T{sub N} operation is an incomplete substitute for the combined conditions that T symmetry and hermiticity impose on the transition amplitudes in first-order electromagnetic or weak processes. Other misconceptions concerning relationships between T-odd operators and (so called) T-odd observables are discussed.

  3. Radioactive decay.

    PubMed

    Groch, M W

    1998-01-01

    When a parent radionuclide decays to its daughter radionuclide by means of alpha, beta, or isomeric transition, the decay follows an exponential form, which is characterized by the decay constant lambda. The decay constant represents the probability per unit time that a single radioatom will decay. The decay equation can be used to provide a useful expression for radionuclide decay, the half-life, the time when 50% of the radioatoms present will have decayed. Radiotracer half-life has direct implications in nuclear imaging, radiation therapy, and radiation safety because radionuclide half-life affects the ability to evaluate tracer kinetics and create appropriate nuclear images and also affects organ, tumor, and whole-body radiation dose. The number of radioatoms present in a sample is equal to the activity, defined as the number of transitions per unit time, divided by the decay constant; the mass of radioatoms present in a sample can be calculated to determine the specific activity (activity per unit mass). The dynamic relationship between the number of parent and daughter atoms present over time may lead to radioactive equilibrium, which takes two forms--secular and transient--and has direct relevance to generator-produced radionuclides.

  4. Inferring Nuclear Structure Trends of r-PROCESS Nuclei from β-DECAY Measurements

    NASA Astrophysics Data System (ADS)

    Pereira, J.

    2013-03-01

    The present paper reports on several r-process motivated β-decay experiments undertaken at the National Superconducting Cyclotron Laboratory. β-decay half-lives and β-delayed neutron-emission probabilities were measured for neutron-rich nuclei in the region A=80-110. The data are discussed on the basis of quasi-random phase approximation calculations. The emphasis is made on the impact of these data upon calculations of r-process abundances.

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

    SciTech Connect

    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).

  6. On the possibility to measure 0{nu}{beta}{beta}-decay nuclear matrix element for {sup 48}Ca

    SciTech Connect

    Rodin, Vadim

    2011-12-16

    As shown in Ref. [2], the Fermi part M{sub F}{sup 0{nu}} of the total 0{nu}{beta}{beta}-decay nuclear matrix element M{sup 0{nu}} can be related to the single Fermi transition matrix element between the isobaric analog state (IAS) of the ground state of the initial nucleus and the ground state of the final nucleus. The latter matrix element could be measured in charge-exchange reactions. Here we discuss a possibility of such a measurement for {sup 48}Ca and estimate the cross-section of the reaction {sup 48}Ti(n,p){sup 48}Sc(IAS).

  7. Nuclear structure and decay properties of even-even nuclei in Z = 70-80 drip-line region

    NASA Astrophysics Data System (ADS)

    Mahapatro, S.; Lahiri, C.; Kumar, Bharat; Mishra, R. N.; Patra, S. K.

    2016-08-01

    We study nuclear structure properties for various isotopes of Ytterbium (Yb), Hafnium(Hf), Tungsten(W), Osmium(Os), Platinum(Pt) and Mercury(Hg) in Z = 70-80 drip-line region starting from N = 80 to N = 170 within the formalism of relativistic mean field (RMF) theory. The pairing correlation is taken care by using BCS approach. We compared our results with finite range droplet model(FRDM) and experimental data and found that the calculated results are in good agreement. Neutron shell closure is obtained at N = 82 and 126 in this region. We have also studied probable decay mechanisms of these elements.

  8. Nuclear β-decay half-lives in the relativistic point-coupling model

    NASA Astrophysics Data System (ADS)

    Wang, Z. Y.; Niu, Y. F.; Niu, Z. M.; Guo, J. Y.

    2016-08-01

    The self-consistent proton-neutron quasiparticle random phase approximation approach is employed to calculate β-decay half-lives of neutron-rich even-even nuclei with 8≤slant Z≤slant 30. A newly proposed nonlinear point-coupling effective interaction PC-PK1 is used in the calculations. It is found that the isoscalar proton-neutron pairing interaction can significantly reduce β-decay half-lives. With an isospin-dependent isoscalar proton-neutron pairing strength, our results well reproduce the experimental β-decay half-lives, although the pairing strength is not adjusted using the half-lives calculated in this study.

  9. Observation of the acceleration by an electromagnetic field of nuclear beta decay

    NASA Astrophysics Data System (ADS)

    Reiss, H. R.

    2008-02-01

    Measurements are reported of the acceleration of the first-forbidden beta decay of 137Cs by exposure to intense, low-frequency electromagnetic fields. Two separate experiments were done: one in a coaxial cavity, and the other in a coaxial transmission line. The first showed an increase in the beta decay rate of (6.8±3.2)×10-4 relative to the natural rate, and the other resulted in an increase of (6.5±2.0)×10- 4. In addition, a Fourier analysis of the rate of 662 keV gamma emission following from the beta decay in the standing-wave experiment showed a clear indication of the frequency with which the external field was switched on and off. A simultaneously detected gamma emission from a placebo nucleus showed no such peak.

  10. Nuclear Structure Investigations Of Heavy Nuclei And The Decay Of SHE

    SciTech Connect

    Kuusiniemi, P.

    2005-04-05

    Within the framework of our studies of proton rich nuclei around the N 126 and N = 152 neutron shells we have performed a series of {alpha}-{gamma}-coincidence studies. The nuclei of interest were separated in-flight by the velocity filter SHIP and implanted into a position sensitive 16-strip PIPS-detector where their arrival and subsequent {alpha}-decays were registered. Associated {gamma}-rays were detected by a Ge-Clover-detector. In the present work recent results concerning 216Th and {alpha}-decay chains of 251No and 257Db are given together with brief discussion.

  11. 0{nu}{beta}{beta}-decay nuclear matrix elements with self-consistent short-range correlations

    SciTech Connect

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

    2009-05-15

    A self-consistent calculation of nuclear matrix elements of the neutrinoless double-beta decays (0{nu}{beta}{beta}) of {sup 76}Ge, {sup 82}Se, {sup 96}Zr, {sup 100}Mo, {sup 116}Cd, {sup 128}Te, {sup 130}Te, and {sup 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 0{nu}{beta}{beta} 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 0{nu}{beta}{beta}-decay matrix elements.

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

    SciTech Connect

    Chasteler, R.M. . Dept. of Chemistry Lawrence Berkeley Lab., CA )

    1990-04-26

    Neutron-rich rare-earth nuclei were produced in multinucleon transfer reactions of {sup 170}Er and {sup 176}Yb projectiles on {sup 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, {sup 169}Dy (t {sub 1/2} {equals} 39 {plus minus} 8 s) and {sup 174}Er(t{sub 1/2} {equals} 3.3 {plus minus} 0.2 m) were discovered and their decay characteristics determined. The decay schemes for two previously identified isotopes, {sup 168}Dy (t{sub 1/2} {equals} 8.8 {plus minus} 0.3 m) and {sup 171}Ho (t{sub 1/2} {equals} 55 {plus minus} 3 s), were characterized. Evidence for a new isomer of 3.0 m {sup 168}Ho{sup g}, {sup 168}Ho{sup m} (t{sub 1/2} {equals} 132 {plus minus} 4 s) which decays by isomeric transition (IT) is presented. Beta particle endpoint energies were determined for the decay of {sup 168}Ho{sup g}, {sup 169}Dy, {sup 171}Ho, and {sup 174}Er, the resulting Q{beta}-values are: 2.93 {plus minus} 0.03, 3.2 {plus minus} 0.3, 3.2 {plus minus} 0.6, and 1.8 {plus minus} 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.

  13. Very Low Energy Protons From the Beta Decay of Proton Rich Nuclei For Nuclear Astrophysics

    SciTech Connect

    Simmons, E.; Trache, L.; Banu, A.; McCleskey, M.; Roeder, B.; Spiridon, A.; Tribble, R. E.; Saastamoinen, A.; Aysto, J.; Davinson, T.; Woods, P. J.; Lotay, G. J.

    2010-03-01

    We have developed a new experimental technique to measure very low energy protons from beta-delayed p-decay of proton-rich nuclei produced and separated with the MARS recoil spectrometer at TAMU. Recently we have investigated the beta-delayed p-decays of {sup 23}Al and {sup 31}Cl and obtained information on the resonances in the reactions {sup 22}Na(p,gamma){sup 23}Mg and {sup 30}P(p,gamma){sup 31}S, respectively. These reactions are important in explosive H-burning in Novae. A simple setup consisting of a telescope made of a thin double sided Si strip detector (p-detector) backed or sandwiched between two thick Si detectors (beta-detectors) was designed. We studied two different p-detectors and found that the thinner detectors with a small cell size are best to measure proton energies as low as 2-300 keV.

  14. Report on the workshop "Decay spectroscopy at CARIBU: advanced fuel cycle applications, nuclear structure and astrophysics". 14-16 April 2011, Argonne National Laboratory, USA.

    SciTech Connect

    Kondev, F.; Carpenter, M.P.; Chowdhury, P.; Clark, J.A.; Lister, C.J.; Nichols, A.L.; Swewryniak, D.

    2011-10-06

    A workshop on 'Decay Spectroscopy at CARIBU: Advanced Fuel Cycle Applications, Nuclear Structure and Astrophysics' will be held at Argonne National Laboratory on April 14-16, 2011. The aim of the workshop is to discuss opportunities for decay studies at the Californium Rare Isotope Breeder Upgrade (CARIBU) of the ATLAS facility with emphasis on advanced fuel cycle (AFC) applications, nuclear structure and astrophysics research. The workshop will consist of review and contributed talks. Presentations by members of the local groups, outlining the status of relevant in-house projects and availabile equipment, will also be organized. time will also be set aside to discuss and develop working collaborations for future decay studies at CARIBU. Topics of interest include: (1) Decay data of relevance to AFC applications with emphasis on reactor decay heat; (2) Discrete high-resolution gamma-ray spectroscopy following radioactive decya and related topics; (3) Calorimetric studies of neutron-rich fission framgents using Total ABsorption Gamma-Ray Spectrometry (TAGS) technique; (4) Beta-delayed neutron emissions and related topics; and (5) Decay data needs for nuclear astrophysics.

  15. Abrupt changes in alpha-decay systematics as a manifestation of collective nuclear modes

    SciTech Connect

    Qi, C.; Liotta, R. J.; Wyss, R. A.; Andreyev, A. N.; Huyse, M.; Van Duppen, P.

    2010-06-15

    An abrupt change in alpha-decay systematics around the N=126 neutron shell closure is discussed. It is explained as a sudden hindrance of the clustering of the nucleons that eventually form the alpha particle. This is because the clustering induced by the pairing mode acting upon the four nucleons is inhibited if the configuration space does not allow a proper manifestation of the pairing collectivity.

  16. Evidence against correlations between nuclear decay rates and Earth-Sun distance

    SciTech Connect

    Norman, Eric B.; Browne, Edgardo; Shugart, Howard A.; Joshi, Tenzing H.; Firestone, Richard B.

    2008-12-08

    We have reexamined our previously published data to search for evidence of correlations between the rates for the alpha, beta-minus, beta-plus, and electron capture decays of 22Na, 44Ti, 108Agm, 121Snm, 133Ba, and 241Am and the Earth?Sun distance. We find no evidence for such correlations and set limits on the possible amplitudes of such correlations substantially smaller than those observed in previous experiments.

  17. Nuclear potentials for sub-barrier fusion and cluster decay in {sup 14}C, {sup 18}O+{sup 208}Pb systems

    SciTech Connect

    Sagaidak, R. N.; Tretyakova, S. P.; Khlebnikov, S. V.; Ogloblin, A. A.; Rowley, N.; Trzaska, W. H.

    2007-09-15

    Near-barrier fusion excitation functions for the {sup 14}C and {sup 18}O+{sup 208}Pb reactions have been analyzed in the framework of the barrier-passing model using different forms of the nuclear potential and the phenomenology of a fluctuating barrier. The best-fit fusion potentials were used to estimate cluster decay probabilities from the corresponding ground states of Ra and Th (i.e., for the inverse decay process). The analysis supports the ''{alpha}-decay-like'' scenario for carbon and oxygen emission from these nuclei.

  18. New Nuclear Structure and Decay Results in the {sup 76}Ge–{sup 76}As System

    SciTech Connect

    Domula, A.R.; Gehre, D.; Zuber, K.; Drohé, J.C.; Nankov, N.; Plompen, A.J.M.; Rouki, C.; Stanoiu, M.; Klix, A.; Buffler, A.; Geduld, D.; Smit, F.D.; Vermeulen, C.; Maleka, P.; Newman, R.T.; Nolte, R.; Wallner, A.

    2014-06-15

    The process of neutrinoless double beta decay (0νββ) plays a key role in modern neutrino physics. Experiments on {sup 76}Ge 0νββ-decay using germanium semiconductors are at the forefront in this field. Due to the extremely low count rates expected for this rare decay, any kind of background event in the detector, especially at energies close to Qββ=2039.006 keV must be avoided. Therefore, a careful investigation on the neutron-induced background was carried out. In this scope experiments investigating the inelastic neutron excitation of the lower lying and the 69{sup th} excited level of {sup 76}Ge have been performed. The existence of a 2040.7 keV gamma-ray, that occurs by the de-excitation of the 69{sup th} excited level, was confirmed. Interfering background from {sup 68}Ge was studied via cross-section measurements of the {sup nat}Ge(n,jn){sup 68}Ge reaction using quasi-monoenergetic neutrons and accelerator mass specrometry for {sup 68}Ge detection. In order to explore the matrix element for the transition between the {sup 76}Ge-{sup 76}As ground states, the electron–capture of {sup 76}As has been measured for the first time.

  19. Nuclear Structure Relevant to Double-beta Decay: Studies of 76Ge and 76Se using Inelastic Neutron Scattering

    NASA Astrophysics Data System (ADS)

    Crider, Benjamin P.

    While neutrino oscillations indicate that neutrino flavors mix and that neutrinos have mass, they do not supply information on the absolute mass scale of the three flavors of neutrinos. Currently, the only viable way to determine this mass scale is through the observation of the theoretically predicted process of neutrinoless double-beta decay (0nubetabeta). This yet-to-be-observed decay process is speculated to occur in a handful of nuclei and has predicted half-lives greater than 1025 years. Observation of 0nubetabeta is the goal of several large-scale, multinational efforts and consists of detecting a sharp peak in the summed energies at the Q-value of the reaction. An exceptional candidate for the observation of 0nubetabeta is 76Ge, which offers an excellent combination of capabilities and sensitivities, and two such collaborations, MAJORANA and GERDA, propose tonne-scale experiments that have already begun initial phases using a fraction of the material. The absolute scale of the neutrino masses hinges on a matrix element, which depends on the ground-state wave functions for both the parent (76Ge) and daughter (76Se) nuclei in the 0nubetabeta decay and can only be calculated from nuclear structure models. Efforts to provide information on the applicability of these models have been undertaken at the University of Kentucky Accelerator Laboratory using gamma-ray spectroscopy following inelastic scattering reactions with monoenergetic, accelerator-produced fast neutrons. Information on new energy levels and transitions, spin and parity assignments, lifetimes, multipole mixing ratios, and transition probabilities have been determined for 76Se, the daughter of 76Ge 0nubetabeta, up to 3.0 MeV. Additionally, inaccuracies in the accepted level schemes have been addressed. Observation of 0nubetabeta requires precise knowledge of potential contributors to background within the region of interest, i.e., approximately 2039 keV for 76Ge. In addition to backgrounds

  20. Nuclear transition matrix elements for Majoron-accompanied neutrinoless double-β decay within a projected-Hartree-Fock-Bogoliubov model

    NASA Astrophysics Data System (ADS)

    Rath, P. K.; Chandra, R.; Chaturvedi, K.; Lohani, P.; Raina, P. K.

    2016-02-01

    The model-dependent uncertainties in the nuclear transition matrix elements for the Majoron-accompanied neutrinoless double-β decay (0+→0+transition) of Zr,9694, 100Mo, Te,130128, and 150Nd isotopes are calculated by employing the projected-Hartree-Fock-Bogoliubov formalism with four different parametrizations of the pairing plus multipolar two-body interactions and three different parametrizations of the Jastrow short-range correlations. Uncertainties in the nuclear transition matrix elements turn out to be less than 15% and 21% for decays involving the emission of single and double Majorons, respectively.

  1. Search for the electromagnetic decay of {Delta}(1232) resonance in nuclear matter

    SciTech Connect

    Badala, A.; Barbera, R.; Gulino, M.; Palmeri, A.; Pappalardo, G.S.; Riggi, F.; Russo, A.C.; Russo, G.; Turrisi, R.; Barbera, R.; Gulino, M.; Riggi, F.; Russo, G.; Turrisi, R.; Bonasera, A.

    1998-01-01

    In order to inquire into the existence and significance of non-nucleonic degrees of freedom in the intermediate-energy regime, the production of protons and high-energy photons (E{sub {gamma}}{gt}30 MeV) emitted in the reaction {sup 36}Ar+{sup 27}Al at 95 MeV/nucleon has been studied. The quantitative analysis of the ({gamma}-p) invariant-mass and relative-angle distributions shows evidences of {Delta}(1232)-resonance excitation and {Delta}{r_arrow}N{gamma} decay. Experimental data are in agreement with microscopic theoretical calculations. {copyright} {ital 1998} {ital The American Physical Society}

  2. Evidence Against Correlations Between Nuclear Decay Rates and Earth-Sun Distance

    SciTech Connect

    Norman, E B; Browne, E; Shugart, H A; Joshi, T H; Firestone, R B

    2008-10-21

    We have reexamined our previously published data to search for evidence of correlations between the rates for the alpha, beta-minus, beta-plus, and electron-capture decays of {sup 22}Na, {sup 44}Ti, {sup 108}Ag{sup m}, {sup 121}Sn{sup m}, {sup 133}Ba, and {sup 241}Am and the Earth-Sun distance. We find no evidence for such correlations and set limits on the possible amplitudes of such correlations substantially smaller than those observed in previous experiments.

  3. Ground state proton radioactivity from 121Pr: when was this exotic nuclear decay mode first discovered?

    PubMed

    Robinson, A P; Woods, P J; Seweryniak, D; Davids, C N; Carpenter, M P; Hecht, A A; Peterson, D; Sinha, S; Walters, W B; Zhu, S

    2005-07-15

    Ground-state proton radioactivity has been identified from 121Pr. A transition with a proton energy of E(p)=882(10) keV [Q(p)=900(10) keV] and half-life t(1/2)=10(+6)(-3) ms has been observed and is assigned to the decay of a highly prolate deformed 3/2(+) or 3/2(-) Nilsson state. The present result is found to be incompatible with a previously reported observation of ground-state proton radioactivity from 121Pr, which would have represented the discovery of this phenomenon.

  4. Dynamics of Nuclear Receptor Helix-12 Switch of Transcription Activation by Modeling Time-Resolved Fluorescence Anisotropy Decays

    PubMed Central

    Batista, Mariana R.B.; Martínez, Leandro

    2013-01-01

    Nuclear hormone receptors (NRs) are major targets for pharmaceutical development. Many experiments demonstrate that their C-terminal Helix (H12) is more flexible in the ligand-binding domains (LBDs) without ligand, this increased mobility being correlated with transcription repression and human diseases. Crystal structures have been obtained in which the H12 is extended, suggesting the possibility of large amplitude H12 motions in solution. However, these structures were interpreted as possible crystallographic artifacts, and thus the microscopic nature of H12 movements is not well known. To bridge the gap between experiments and molecular models and provide a definitive picture of H12 motions in solution, extensive molecular dynamics simulations of the peroxisome proliferator-activated receptor-γ LBD, in which the H12 was bound to a fluorescent probe, were performed. A direct comparison of the modeled anisotropy decays to time-resolved fluorescence anisotropy experiments was obtained. It is shown that the decay rates are dependent on the interactions of the probe with the surface of the protein, and display little correlation with the flexibility of the H12. Nevertheless, for the probe to interact with the surface of the LBD, the H12 must be folded over the body of the LBD. Therefore, the molecular mobility of the H12 should preserve the globularity of the LBD, so that ligand binding and dissociation occur by diffusion through the surface of a compact receptor. These results advance the comprehension of both ligand-bound and ligand-free receptor structures in solution, and also guide the interpretation of time-resolved anisotropy decays from a molecular perspective, particularly by the use of simulations. PMID:24094408

  5. Activity determination of (227)Ac and (223)Ra by means of liquid scintillation counting and determination of nuclear decay data.

    PubMed

    Kossert, Karsten; Bokeloh, Karen; Dersch, Rainer; Nähle, Ole

    2014-10-23

    The activity concentrations of solutions containing (227)Ac and (223)Ra in equilibrium with their progenies, respectively, were measured by means of liquid scintillation counting. The counting efficiencies were determined with the aid of a free parameter model. The corresponding calculations comprise the computation of several alpha, beta and beta/gamma branches. For short-lived progenies like (215)Po the counting efficiency depends on the counter dead time. Measurements were made in custom-built triple-to-double coincidence ratio (TDCR) systems and various dead-time adjustments were used. In addition, two commercial counters were used to apply the CIEMAT/NIST efficiency tracing technique using (3)H as a tracer. For the (227)Ac solution, the overall relative standard uncertainty of the activity concentration was found to be 0.93%. The dominant uncertainty components are assigned to the efficiency computation of the low-energy beta transitions of (227)Ac. We have identified a need for improved (227)Ac decay data to achieve a significant reduction in the overall uncertainty. In the case of (223)Ra, the activity concentrations were determined with relative standard uncertainties below 0.3%. Hence, PTB is prepared to provide calibration services for (223)Ra, which is an isotope of increasing interest in nuclear medicine. The TDCR measurements were also used to determine the half-life of (223)Ra. The decay was followed for about 58 days and a half-life T1/2=11.4362(50)d was obtained.

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

    NASA Astrophysics Data System (ADS)

    Cappuzzello, F.; Agodi, C.; Aciksoz, E.; Acosta, L.; Aslanouglou, X.; Auerbach, N.; Bijker, R.; Bonanno, D.; Bongiovanni, D.; Borello, T.; Boudhaim, S.; Bouhssa, M. L.; Boztosun, I.; Calabretta, L.; Calanna, A.; Carbone, D.; Cavallaro, M.; Calvo, D.; Chávez Lomelí, E. R.; Colonna, M.; D'Agostino, G.; Deshmukh, N.; de Faria, P. N.; Ferrero, A.; Foti, A.; Finocchiaro, P.; Gomes, P. R. S.; Greco, V.; Hacisalihoglu, A.; Housni, Z.; Khouaja, A.; Inchaou, J.; Lanzalone, G.; La Via, F.; Lay, J. A.; Lenske, H.; Linares, R.; Lubian, J.; Iazzi, F.; Introzzi, R.; Lavagno, A.; Lo Presti, D.; Medina, N.; Mendes, D. R.; Muoio, A.; Oliveira, J. R. B.; Pakou, A.; Pandola, L.; Rifuggiato, D.; Rodrigues, M. R. D.; Santagati, G.; Santopinto, E.; Scaltrito, L.; Sgouros, O.; Solakcı, S. O.; Soukeras, V.; Tudisco, S.; Vsevolodovna, R. I. M.; Zagatto, V.

    2016-07-01

    An innovative technique to access the nuclear matrix elements entering the expression of the life time of the double beta decay by relevant cross section 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 heavy-ion beams, already in operation at INFN Laboratory Nazionali del Sud in Catania (Italy). However, a major upgrade is foreseen for the INFN-LNS research infrastructure to cope with beam currents as high as several ppA required by the project.

  7. Occupancies of individual orbits, and the nuclear matrix element of the {sup 76}Ge neutrinoless {beta}{beta} decay

    SciTech Connect

    Menendez, J.; Poves, A.

    2009-10-15

    We discuss the variation of the nuclear matrix element (NME) for the neutrinoless double beta (0{nu}{beta}{beta}) decay of {sup 76}Ge when the wave functions are constrained to reproduce the experimental occupancies of the two nuclei involved in the transition. In the interacting shell model description the value of the NME is enhanced about 15% compared to previous calculations, whereas in the QRPA the NME's are reduced by 20%-30%. This diminishes the discrepancies between both approaches. In addition, we discuss the effect of the short-range correlations on the NME in light of the recently proposed parametrizations based on a consistent renormalization of the 0{nu}{beta}{beta} transition operator.

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

    DOE R&D Accomplishments Database

    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.

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

    SciTech Connect

    Chadwick, M.B.; Herman, M.; Author : 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

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

    NASA Astrophysics Data System (ADS)

    Chadwick, M. B.; Herman, M.; Obložinský, 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 235,238U and 239Pu 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 239Pu; 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 range

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

    SciTech Connect

    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.

  12. Additional experimental evidence for a solar influence on nuclear decay rates

    NASA Astrophysics Data System (ADS)

    Jenkins, Jere H.; Herminghuysen, Kevin R.; Blue, Thomas E.; Fischbach, Ephraim; Javorsek, Daniel; Kauffman, Andrew C.; Mundy, Daniel W.; Sturrock, Peter A.; Talnagi, Joseph W.

    2012-09-01

    Additional experimental evidence is presented in support of the recent hypothesis that a possible solar influence could explain fluctuations observed in the measured decay rates of some isotopes. These data were obtained during routine weekly calibrations of an instrument used for radiological safety at The Ohio State University Research Reactor using 36Cl. The detector system used was based on a Geiger-Müller gas detector, which is a robust detector system with very low susceptibility to environmental changes. A clear annual variation is evident in the data, with a maximum relative count rate observed in January/February, and a minimum relative count rate observed in July/August, for seven successive years from July 2005 to June 2011. This annual variation is not likely to have arisen from changes in the detector surroundings, as we show here.

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

    SciTech Connect

    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)

  14. Biased distributions and decay of long interspersed nuclear elements in the chicken genome.

    PubMed

    Abrusán, György; Krambeck, Hans-Jürgen; Junier, Thomas; Giordano, Joti; Warburton, Peter E

    2008-01-01

    The genomes of birds are much smaller than mammalian genomes, and transposable elements (TEs) make up only 10% of the chicken genome, compared with the 45% of the human genome. To study the mechanisms that constrain the copy numbers of TEs, and as a consequence the genome size of birds, we analyzed the distributions of LINEs (CR1's) and SINEs (MIRs) on the chicken autosomes and Z chromosome. We show that (1) CR1 repeats are longest on the Z chromosome and their length is negatively correlated with the local GC content; (2) the decay of CR1 elements is highly biased, and the 5'-ends of the insertions are lost much faster than their 3'-ends; (3) the GC distribution of CR1 repeats shows a bimodal pattern with repeats enriched in both AT-rich and GC-rich regions of the genome, but the CR1 families show large differences in their GC distribution; and (4) the few MIRs in the chicken are most abundant in regions with intermediate GC content. Our results indicate that the primary mechanism that removes repeats from the chicken genome is ectopic exchange and that the low abundance of repeats in avian genomes is likely to be the consequence of their high recombination rates.

  15. Change of nuclear configurations in the neutrinoless double-β decay of 130Te →130Be and 136Xe136Ba

    NASA Astrophysics Data System (ADS)

    Entwisle, J. P.; Kay, B. P.; Tamii, A.; Adachi, S.; Aoi, N.; Clark, J. A.; Freeman, S. J.; Fujita, H.; Fujita, Y.; Furuno, T.; Hashimoto, T.; Hoffman, C. R.; Ideguchi, E.; Ito, T.; Iwamoto, C.; Kawabata, T.; Liu, B.; Miura, M.; Ong, H. J.; Schiffer, J. P.; Sharp, D. K.; Süsoy, G.; Suzuki, T.; Szwec, S. V.; Takaki, M.; Tsumura, M.; Yamamoto, T.

    2016-06-01

    The change in the configuration of valence protons between the initial and final states in the neutrinoless double-β decay of 130Te → 130Be and of 136Xe136Ba has been determined by measuring the cross sections of the (d ,3He) reaction with 101-MeV deuterons. Together with our recent determination of the relevant neutron configurations involved in the process, a quantitative comparison with the latest shell-model and interacting-boson-model calculations reveals significant discrepancies. These are the same calculations used to determine the nuclear matrix elements governing the rate of neutrinoless double-β decay in these systems.

  16. Nuclear matrix elements for 0νβ{sup −}β{sup −} decays: Comparative analysis of the QRPA, shell model and IBM predictions

    SciTech Connect

    Civitarese, Osvaldo; Suhonen, Jouni

    2013-12-30

    In this work we report on general properties of the nuclear matrix elements involved in the neutrinoless double β{sup −} decays (0νβ{sup −}β{sup −} decays) of several nuclei. A summary of the values of the NMEs calculated along the years by the Jyväskylä-La Plata collaboration is presented. These NMEs, calculated in the framework of the quasiparticle random phase approximation (QRPA), are compared with those of the other available calculations, like the Shell Model (ISM) and the interacting boson model (IBA-2)

  17. Fermi to Gamow-Teller Mixing Ratios in the Nuclear Beta Decays of COBALT-58 and COBALT-56.

    NASA Astrophysics Data System (ADS)

    Lee, Wen-Piao

    1981-06-01

    The Fermi to Gamow-Teller mixing ratios, y = C(,V)M(,F)/C(,A)M(,GT), in the isospin-hindered beta decays ((DELTA)J=0, T=('(+OR -))1) of ('58)Co and ('56)Co have been accurately determined from extensive and detailed studies of the directional distributions of beta rays and gamma rays emitted from oriented ('58)Co and ('56)Co nuclei. The cobalt nuclei were oriented in a thin foil of permendur (49%Co, 49%Fe, and 2%V) magnetically saturated at ultralow temperatures (10('-2o)K). The nuclear orientation system employed has the distinguished features of excellent long-term temperature stability and of allowing beta rays be measured at almost any desired angle with respect to the nuclear orientation axis with very little deflections from their original trajectories by the applied magnetizing fields. Beta-ray and gamma-ray spectra were measured, with a Si(Li) detector and a Ge(Li) detector respectively, at four different angles with respect to the nuclear orientation axis. The gamma-ray background in the beta-ray spectra is removed by means of a mechanical shutter. The beta -ray asymmetries and the gamma-ray anisotropies were determined independently at each angle by normalizing the cold ((TURNEQ)10(' -2o)K) spectra by the corresponding warm (4.2(DEGREES)K) spectra taken at the same angle. Necessary corrections made on the beta-ray spectra due to the various experimental effects are described in detail. The experimental beta -ray asymmetries after the proper corrections were found to be in very good agreement with the theoretical expectations over a wide energy region. Including all estimated systematic errors, the beta-ray asymmetry parameters, A(,(beta)), were determined to be A(,(beta))('58) = 0.341 (+OR-) 0.020 for ('58)Co and A('56) = 0.352 (+OR-) 0.015 for ('56)Co. The Fermi to Gamov-Teller mixing ratios y corresponding to these A(,(beta))'s are y('58) = -0.005 (+OR-) 0.012 for ('58)Co and y('56) = -0.086 (+OR-) 0.008 for ('56)Co. The obtained result of y('56) is in

  18. Experimental investigations on decay heat removal in advanced nuclear reactors using single heater rod test facility: Air alone in the annular gap

    SciTech Connect

    Bopche, Santosh B.; Sridharan, Arunkumar

    2010-11-15

    During a loss of coolant accident in nuclear reactors, radiation heat transfer accounts for a significant amount of the total heat transfer in the fuel bundle. In case of heavy water moderator nuclear reactors, the decay heat of a fuel bundle enclosed in the pressure tube and outer concentric calandria tube can be transferred to the moderator. Radiation heat transfer plays a significant role in removal of decay heat from the fuel rods to the moderator, which is available outside the calandria tube. A single heater rod test facility is designed and fabricated as a part of preliminary investigations. The objective is to anticipate the capability of moderator to remove decay heat, from the reactor core, generated after shut down. The present paper focuses mainly on the role of moderator in removal of decay heat, for situation with air alone in the annular gap of pressure tube and calandria tube. It is seen that the naturally aspirated air is capable of removing the heat generated in the system compared to the standstill air or stagnant water situations. It is also seen that the flowing moderator is capable of removing a greater fraction of heat generated by the heater rod compared to a stagnant pool of boiling moderator. (author)

  19. Nuclear-structure dependence of O (. alpha. ) corrections to Fermi decays and the value of the Kobayashi-Maskawa matrix element V sub ud

    SciTech Connect

    Jaus, W.; Rasche, G. )

    1990-01-01

    We calculate nuclear-structure corrections to the {ital ft} values of the eight accurately measured superallowed {beta}{sup +} decays. The statistical fit for the average {ital ft} value is very good. The resulting new value for the matrix element of the Kobayashi-Maskawa (KM) matrix is {vert bar}{ital V}{sub {ital ud}}{vert bar}=0.9735(5). The error in {vert bar}{ital V}{sub {ital ud}}{vert bar} has thus been reduced by 50%. Combining this value for {vert bar}{ital V}{sub {ital ud}}{vert bar} with the presently accepted results from kaon-, hyperon-, and {ital B}-decay constraints, the unitarity of the KM matrix for three generations of quarks seems to be violated.

  20. Decay Data Evaluation Project (DDEP): evaluation of the main 233Pa decay characteristics.

    PubMed

    Chechev, Valery P; Kuzmenko, Nikolay K

    2006-01-01

    The results of a decay data evaluation are presented for 233Pa (beta-) decay to nuclear levels in 233U. These evaluated data have been obtained within the Decay Data Evaluation Project using information published up to 2005.

  1. Decay Data Evaluation Project (DDEP): evaluation of the main 233Pa decay characteristics.

    PubMed

    Chechev, Valery P; Kuzmenko, Nikolay K

    2006-01-01

    The results of a decay data evaluation are presented for 233Pa (beta-) decay to nuclear levels in 233U. These evaluated data have been obtained within the Decay Data Evaluation Project using information published up to 2005. PMID:16574422

  2. α versus non-α cluster decays of the excited compound nucleus *124Ce using various formulations of the nuclear proximity potential

    NASA Astrophysics Data System (ADS)

    Kaur, Arshdeep; Chopra, Sahila; Gupta, Raj K.

    2015-06-01

    The earlier study of *124Ce formed in the 32S+92Mo reaction at an above barrier beam energy of 150 MeV, using the pocket formula of Blocki et al. for the nuclear proximity potential in the dynamical cluster-decay model (DCM), is extended to the use of other nuclear interaction potentials derived from the Skyrme energy density functional (SEDF) based on the semiclassical extended Thomas Fermi (ETF) approach under the frozen density approximation. The Skyrme forces used are the old SII, SIII, SIV, SKa, SkM, and SLy4 and new GSkI and KDE0(v1), given for both normal and isospin-rich nuclei. It is found that the α -nucleus structure, over the non-α nucleus structure, is preferred for only two Skyrme forces, the SIII and KDE0(v1). An extended intermediate mass fragments (IMFs) window, along with the new decay region of heavy mass fragments (HMFs) and the near-symmetric and symmetric fission fragments which, on adding the complementary heavy fragments, corresponds to (A /2 )±12 mass region of the fusion-fission (ff) process, are predicted by considering cross sections of orders observed in the experiment under study. For the predicted (total) fusion cross section, the survival probability Psurv of the compound nucleus (CN) against fission is shown to be very small because of the very large predicted ff component. On the other hand, the CN formation probability PCN is found to be nearly equal to 1, and hence the decay under study is a pure CN decay for all the nuclear potentials considered, since the estimated noncompound nucleus (nCN) content is almost negligible. We have also applied the extended-Wong model of Gupta and collaborators, and find that the ℓmax values and total fusion cross sections are of the same order as for the DCM. Thus, the extended-Wong model, which describes only the total fusion cross section in terms of the barrier characteristics of the entrance channel nuclei, could be useful for initial experimental studies to be fully treated using the DCM

  3. Characterization of Nuclear Recoils in High Pressure Xenon Gas: Towards a Simultaneous Search for WIMP Dark Matter and Neutrinoless Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Renner, J.; Gehman, V. M.; Goldschmidt, A.; Oliveira, C. A. B.; Nygren, D.

    Xenon has recently been the medium of choice in several large scale detectors searching for WIMP dark matter and neutrinoless double beta decay. Though present-day large scale experiments use liquid xenon, the gas phase o_ers advantages favorable to both types of searches such as improved intrinsic energy resolution and fewer fluctuations in the partition of deposited energy between scintillation and ionization channels. We recently constructed a high pressure xenon gas TPC as a prototype for the NEXT (Neutrino Experiment with a Xenon TPC) neutrinoless double beta decay experiment and have demonstrated the feasibility of 0.5% FWHM energy resolution at the 136Xe double beta Q-value with 3-D tracking capabilities. We now present results from this prototype on the simultaneous observation of scintillation and ionization produced by nuclear recoils at approximately 14 bar pressure. The recoils were produced by neutrons of approximately 2-6 MeV emitted from a radioisotope plutonium-beryllium source, and primary scintillation (S1) and electroluminescent photons produced by ionization (S2) were observed. We discuss the potential of gaseous xenon to distinguish between electron and nuclear recoils through the ratio of these two signals S2/S1. From these results combined with the possibility of using columnar recombination to sense nuclear recoil directionality at high pressures we envision a dual-purpose, ton-scale gaseous xenon detector capable of a combined search for WIMP dark matter and neutrinoless double beta decay. This work has been performed within the context of the NEXT collaboration.

  4. Characterization of Nuclear Recoils in High Pressure Xenon Gas: Towards a Simultaneous Search for WIMP Dark Matter and Neutrinoless Double Beta Decay

    DOE PAGES

    Renner, J.; Gehman, V. M.; Goldschmidt, A.; Oliveira, C. A.B.; Nygren, D.

    2015-03-24

    Xenon has recently been the medium of choice in several large scale detectors searching for WIMP dark matter and neutrinoless double beta decay. Though present-day large scale experiments use liquid xenon, the gas phase offers advantages favorable to both types of searches such as improved intrinsic energy resolution and fewer fluctuations in the partition of deposited energy between scintillation and ionization channels. We recently constructed a high pressure xenon gas TPC as a prototype for the NEXT (Neutrino Experiment with a Xenon TPC) neutrinoless double beta decay experiment and have demonstrated the feasibility of 0.5% FWHM energy resolution at themore » 136Xe double beta Q-value with 3-D tracking capabilities. We now present results from this prototype on the simultaneous observation of scintillation and ionization produced by nuclear recoils at approximately 14 bar pressure. The recoils were produced by neutrons of approximately 2-6 MeV emitted from a radioisotope plutonium-beryllium source, and primary scintillation (S1) and electroluminescent photons produced by ionization (S2) were observed. We discuss the potential of gaseous xenon to distinguish between electron and nuclear recoils through the ratio of these two signals S2/S1. From these results combined with the possibility of using columnar recombination to sense nuclear recoil directionality at high pressures we envision a dual-purpose, ton-scale gaseous xenon detector capable of a combined search for WIMP dark matter and neutrinoless double beta decay. This work has been performed within the context of the NEXT collaboration.« less

  5. Characterization of Nuclear Recoils in High Pressure Xenon Gas: Towards a Simultaneous Search for WIMP Dark Matter and Neutrinoless Double Beta Decay

    SciTech Connect

    Renner, J.; Gehman, V. M.; Goldschmidt, A.; Oliveira, C. A.B.; Nygren, D.

    2015-03-24

    Xenon has recently been the medium of choice in several large scale detectors searching for WIMP dark matter and neutrinoless double beta decay. Though present-day large scale experiments use liquid xenon, the gas phase offers advantages favorable to both types of searches such as improved intrinsic energy resolution and fewer fluctuations in the partition of deposited energy between scintillation and ionization channels. We recently constructed a high pressure xenon gas TPC as a prototype for the NEXT (Neutrino Experiment with a Xenon TPC) neutrinoless double beta decay experiment and have demonstrated the feasibility of 0.5% FWHM energy resolution at the 136Xe double beta Q-value with 3-D tracking capabilities. We now present results from this prototype on the simultaneous observation of scintillation and ionization produced by nuclear recoils at approximately 14 bar pressure. The recoils were produced by neutrons of approximately 2-6 MeV emitted from a radioisotope plutonium-beryllium source, and primary scintillation (S1) and electroluminescent photons produced by ionization (S2) were observed. We discuss the potential of gaseous xenon to distinguish between electron and nuclear recoils through the ratio of these two signals S2/S1. From these results combined with the possibility of using columnar recombination to sense nuclear recoil directionality at high pressures we envision a dual-purpose, ton-scale gaseous xenon detector capable of a combined search for WIMP dark matter and neutrinoless double beta decay. This work has been performed within the context of the NEXT collaboration.

  6. Decay data evaluation project (DDEP): updated evaluations of the 233Th and 241Am decay characteristics.

    PubMed

    Chechev, Valery P; Kuzmenko, Nikolay K

    2010-01-01

    The results of new decay data evaluations are presented for (233)Th (beta(-)) decay to nuclear levels in (233)Pa and (241)Am (alpha) decay to nuclear levels in (237)Np. These evaluated data have been obtained within the Decay Data Evaluation Project using information published up to 2009.

  7. Decay Data Evaluation Project (DDEP): evaluation of the main 243Cm and 245Cm decay characteristics.

    PubMed

    Chechev, Valery P

    2012-09-01

    The results of new decay data evaluations are presented for (243)Cm (α) decay to nuclear levels in (239)Pu and (245)Cm (α) decay to nuclear levels in (241)Pu. These evaluated data have been obtained within the Decay Data Evaluation Project using information published up to 2011.

  8. Evolution of the nuclear structure approaching {sup 78}Ni: {beta} decay of {sup 74-78}Cu

    SciTech Connect

    Roosbroeck, J. van; Witte, H. de; Gorska, M.; Huyse, M.; Kruglov, K.; Pauwels, D.; Thomas, J.-Ch.; Vel, K. van de; Duppen, P. van; Franchoo, S.; Cederkall, J.; Fedoseyev, V.N.; Fynbo, H.; Georg, U.; Jonsson, O.; Koester, U.; Weissman, L.; Mueller, W.F.; Mishin, V.I.; Fedorov, D.

    2005-05-01

    A {beta}-decay study of the even mass {sup 74,76,78}Cu isotopes toward levels in {sup 74,76,78}Zn was performed at the ISOLDE mass separator. The copper isotopes were produced in proton- or neutron-induced fission reactions on {sup 238}U, laser ionized, mass separated, and sent to a {beta}-{gamma} detection system. Half-lives, decay schemes, and possible spin configurations were obtained for the copper isotopes. The results are compared with calculations using schematic forces as well as large-scale shell-model calculations with realistic forces.

  9. Analysis of nuclear materials by energy dispersive x-ray fluorescence and spectral effects of alpha decay

    SciTech Connect

    Worley, Christopher G

    2009-01-01

    Energy dispersive X-ray fluorescence (EDXRF) spectra collected from alpha emitters are complicated by artifacts inherent to the alpha decay process, particularly when using portable instruments. For example, {sup 239}Pu EDXRF spectra exhibit a prominent uranium L X-ray emission peak series due to sample alpha decay rather than source-induced X-ray fluorescence. A portable EDXRF instrument was used to collect spectra from plutonium, americium, and a Pu-contaminated steel sample. The plutonium sample was also analyzed by wavelength dispersive XRF to demonstrate spectral differences observed when using these very different instruments.

  10. Nuclear transparency and double beta decay of molybdenum 100. Annual report, February 1, 1995 - January 31, 1996

    SciTech Connect

    Nicholson, H.W.

    1995-07-01

    This report describes progress in data analysis for a search for neutrinoless double-beta decay of molybdenum 100 and related work, Brookhaven National Laboratory`s Experiment 850 on color transparency, and work on Brookhaven`s EVA detector and the Stanford Linear Accelerator Center`s B factory experiment. 6 refs.

  11. Dose Rate Analysis Capability for Actual Spent Fuel Transportation Cask Contents

    SciTech Connect

    Radulescu, Georgeta; Lefebvre, Robert A; Peplow, Douglas E.; Williams, Mark L; Scaglione, John M

    2014-01-01

    The approved contents for a U.S. Nuclear Regulatory Commission (NRC) licensed spent nuclear fuel casks are typically based on bounding used nuclear fuel (UNF) characteristics. However, the contents of the UNF canisters currently in storage at independent spent fuel storage installations are considerably heterogeneous in terms of fuel assembly burnup, initial enrichment, decay time, cladding integrity, etc. Used Nuclear Fuel Storage, Transportation & Disposal Analysis Resource and Data System (UNF ST&DARDS) is an integrated data and analysis system that facilitates automated cask-specific safety analyses based on actual characteristics of the as-loaded UNF. The UNF-ST&DARDS analysis capabilities have been recently expanded to include dose rate analysis of as-loaded transportation packages. Realistic dose rate values based on actual canister contents may be used in place of bounding dose rate values to support development of repackaging operations procedures, evaluation of radiation-related transportation risks, and communication with stakeholders. This paper describes the UNF-ST&DARDS dose rate analysis methodology based on actual UNF canister contents and presents sample dose rate calculation results.

  12. NUCLEAR AND HEAVY ION PHYSICS: α-decay half-lives of superheavy nuclei and general predictions

    NASA Astrophysics Data System (ADS)

    Dong, Jian-Min; Zhang, Hong-Fei; Wang, Yan-Zhao; Zuo, Wei; Su, Xin-Ning; Li, Jun-Qing

    2009-08-01

    The generalized liquid drop model (GLDM) and the cluster model have been employed to calculate the α-decay half-lives of superheavy nuclei (SHN) using the experimental α-decay Q values. The results of the cluster model are slightly poorer than those from the GLDM if experimental Q values are used. The prediction powers of these two models with theoretical Q values from Audi et al. (QAudi) and Muntian et al. (QM) have been tested to find that the cluster model with QAudi and QM could provide reliable results for Z > 112 but the GLDM with QAudi for Z <= 112. The half-lives of some still unknown nuclei are predicted by these two models and these results may be useful for future experimental assignment and identification.

  13. Nuclear and particle physics aspects of the 2{nu}{beta}{beta}-decay of {sup 150}Nd

    SciTech Connect

    Dvornicky, R.; Simkovic, F.; Faessler, A.

    2007-10-12

    A discussion is given on possible realization of the Single State Dominance (SSD) hypothesis in the case of the two-neutrino double beta decay (2{nu}{beta}{beta}-decay) of {sup l50}Nd with 1{sup -} ground state of the intermediate nucleus. We conclude that the SSD hypothesis is expected to be ruled out by precision measurement of differential characteristics of this process in running NEMO 3 or planed SuperNEMO experiments unlike some unknown low-lying 1{sup +} state of {sup 150}Pm does exist. This problem can be solved via (d,{sup 2}He) charge-exchange experiment on {sup l50}Sm. Further, we address the question about possible violation of the Pauli exclusion principle for neutrinos and its consequences for the energy distributions of the 2{nu}{beta}{beta}-decay of {sup l50}Nd. This phenomenon might be a subject of interest of NEMO 3 and SuperNEMO experiments as well.

  14. Double beta decay: A theoretical overview

    SciTech Connect

    Rosen, S.P.

    1988-01-01

    This paper reviews the theoretical possibility of double beta decay. The titles of the main sections of this paper are: Nuclear physics setting; Particle physics requirements; Kinematical features of the decay modes; Nuclear matrix elements; the Shell model and two-neutrino decay; Quasi-particle random phase approximation; and Future considerations. 18 refs., 7 tabs. (LSP)

  15. Form and Actuality

    NASA Astrophysics Data System (ADS)

    Bitbol, Michel

    A basic choice underlies physics. It consists of banishing actual situations from theoretical descriptions, in order to reach a universal formal construct. Actualities are then thought of as mere local appearances of a transcendent reality supposedly described by the formal construct. Despite its impressive success, this method has left major loopholes in the foundations of science. In this paper, I document two of these loopholes. One is the problem of time asymmetry in statistical thermodynamics, and the other is the measurement problem of quantum mechanics. Then, adopting a broader philosophical standpoint, I try to turn the whole picture upside down. Here, full priority is given to actuality (construed as a mode of the immanent reality self-reflectively being itself) over formal constructs. The characteristic aporias of this variety of "Copernican revolution" are discussed.

  16. Superallowed 0+→0+ nuclear β decays: 2014 critical survey, with precise results for Vu d and CKM unitarity

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

    A new critical survey is presented of all half-life, decay-energy, and branching-ratio measurements related to 20 superallowed 0+→0+β decays. Included are 222 individual measurements of comparable precision obtained from 177 published references. Compared with our last review in 2008, we have added results from 24 new publications and eliminated 9 references, the results from which having been superseded by much more precise modern data. We obtain world-average f t values for each of the 18 transitions that have a complete set of data, then apply radiative and isospin-symmetry-breaking corrections to extract "corrected" F t values. Fourteen of these F t values now have a precision of order 0.1% or better. In the process of obtaining these results we carefully evaluate the available calculations of the isospin-symmetry-breaking corrections by testing the extent to which they lead to F t values consistent with conservation of the vector current. Only one set of calculations satisfactorily meets this condition. The resultant average F t value, when combined with the muon lifetime, yields the up-down quark-mixing element of the Cabibbo-Kobayashi-Maskawa matrix, Vu d=0.974 17 ±0.000 21 . The unitarity test on the top row of the matrix becomes | Vu d|2+| Vu s|2+|Vub| 2=0.999 78 ±0.000 55 if the Particle Data Group (PDG) recommended value for Vu s is used. However, recent lattice QCD calculations, not included yet in the PDG evaluation, have introduced some inconsistency into kaon-decay measurements of Vu s and Vu s/Vu d. We examine the impact of these new results on the unitarity test and conclude that there is no evidence of any statistically significant violation of unitarity. Finally, from the F t -value data we also set limits on the possible existence of scalar interactions.

  17. Electron-capture branch of {sup 100}Tc and tests of nuclear wave functions for double-{beta} decays.

    SciTech Connect

    Sjue, S. K. L.; Melconian, D.; Garcia, A.; Ahmad, I.; Algora, A.; Aysto, J.; Elomaa, V.-V.; Eronen, T.; Hakala, J.; Hoedl, S.; Kankainen, A.; Kessler, T.; Moore, I. D.; Naabe, F.; Penttila, H.; Rahaman, S.; Saastamoinen, A.; Swanson, H. E.; Weber, C.; Triambak, S.; Deryckx, K.; Physics; Univ. of Washington; Texas A&M Univ.; Univ. of Valencia; Hungarian Academy of Sciences; Univ. of Jyvaskyla; Univ. of Michigan

    2008-12-30

    We present a measurement of the electron-capture branch of {sup 100}Tc. Our value, B(EC) = (2.6 {+-} 0.4) x 10{sup -5}, implies that the {sup 100}Mo neutrino absorption cross section to the ground state of {sup 100}Tc is roughly 50% larger than previously thought. Disagreement between the experimental value and QRPA calculations relevant to double-{beta} decay matrix elements persists. We find agreement with previous measurements of the 539.5- and 590.8-keV {gamma}-ray intensities.

  18. RNA-related nuclear functions of human Pat1b, the P-body mRNA decay factor.

    PubMed

    Marnef, Aline; Weil, Dominique; Standart, Nancy

    2012-01-01

    The evolutionarily conserved Pat1 proteins are P-body components recently shown to play important roles in cytoplasmic gene expression control. Using human cell lines, we demonstrate that human Pat1b is a shuttling protein whose nuclear export is mediated via a consensus NES sequence and Crm1, as evidenced by leptomycin B (LMB) treatment. However, not all P-body components are nucleocytoplasmic proteins; rck/p54, Dcp1a, Edc3, Ge-1, and Xrn1 are insensitive to LMB and remain cytoplasmic in its presence. Nuclear Pat1b localizes to PML-associated foci and SC35-containing splicing speckles in a transcription-dependent manner, whereas in the absence of RNA synthesis, Pat1b redistributes to crescent-shaped nucleolar caps. Furthermore, inhibition of splicing by spliceostatin A leads to the reorganization of SC35 speckles, which is closely mirrored by Pat1b, indicating that it may also be involved in splicing processes. Of interest, Pat1b retention in these three nuclear compartments is mediated via distinct regions of the protein. Examination of the nuclear distribution of 4E-T(ransporter), an additional P-body nucleocytoplasmic protein, revealed that 4E-T colocalizes with Pat1b in PML-associated foci but not in nucleolar caps. Taken together, our findings strongly suggest that Pat1b participates in several RNA-related nuclear processes in addition to its multiple regulatory roles in the cytoplasm.

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

    SciTech Connect

    Iselin, L.H.

    1992-12-31

    The use of {sup 14}N nuclear quadrupole resonance (NQR) as a radiation dosimetry tool has only recently been explored. An analytical method for analyzing {sup 14}N NQR complex free induction decays is presented with the background necessary to conduct pulsed NQR experiments. The {sup 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.

  20. Nuclear cascades in Saturn's rings - Cosmic ray albedo neutron decay and origins of trapped protons in the inner magnetosphere

    NASA Technical Reports Server (NTRS)

    Cooper, J. F.

    1983-01-01

    The nearly equatorial trajectory of the Pioneer 11 spacecraft through Saturn's high energy proton radiation belts and under the main A-B-C rings provided a unique opportunity to study the radial dependence of the greater than 30 MeV proton intensities in the belts in terms of models for secondary nucleon production by cosmic ray interactions in the rings, in situ proton injection in the radiation belts by neutron beta decay, magnetospheric diffusion, and absorption by planetary rings and satellites. Maximum trapped proton intensities measured by Pioneer 11 in the radiation belts are compared with calculated intensities and found consistent with trapping times of roughly 40 years and a radial diffusion coefficient of about 10 to the -15th L to the 9th R sub s squared/s. Differential energy spectra proportional to E to the -2 estimated from integral measurements of trapped photons with E greater than 100 MeV are consistent with the beta decay model, but an inferred turndown of the spectra toward lower energies and reported integral proton anisotropies of a specified form both indicate the need for more realistic calculations of the neutron source from the rings and the radiation belt loss processes.

  1. Search for anomalies in the decay of radioactive Mn-54

    NASA Astrophysics Data System (ADS)

    Silverman, M. P.

    2016-06-01

    Recent papers have reported that 54Mn, which decays by electron capture (a weak nuclear interaction) with half-life ∼312 days, is influenced by solar activity. Should this actually occur, new physics would be needed to explain it. This paper reports results of an analysis of 54Mn activity measured over a time interval of ∼3.6 half-lives. If standard nuclear physics applies, the logarithmic residuals of 54Mn activities should form a stationary set of independent random variables whose statistics are determined solely by a constant decay rate λ and initial mean count μ. Analysis of the time-variation, autocorrelation, and power spectra of the 54Mn logarithmic residuals agrees exquisitely with standard nuclear physics. Computer-simulated activities exhibiting periodic decay of amplitude A=αλ show that anomalies would be detectable by these statistical tests for values of α as low as ∼1 part in 104. This limit is about 10 times lower than reported deviations from exponential decay.

  2. Tooth Decay

    MedlinePlus

    ... in your mouth made up mostly of germs. Tooth decay starts in the outer layer, called the enamel. Without a filling, the decay can get deep into the tooth and its nerves and cause a toothache or ...

  3. 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

    SciTech Connect

    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)

  4. Kinetics of Radioactive Decay

    NASA Astrophysics Data System (ADS)

    Nagy, S.

    At present there are over 3,000 known nuclides (see the Appendix in Vol. 2 on the “Table of the Nuclides”), 265 of which are stable, while the rest, i.e., more than 90% of them, are radioactive. The chemical applications of the specific isotopes of chemical elements are mostly connected with the latter group, including quite a number of metastable nuclear isomers, making the kinetics of radioactive decay an important chapter of nuclear chemistry. After giving a phenomenological and then a statistical interpretation of the exponential law, the various combinations of individual decay processes as well as the cases of equilibrium and nonequilibrium will be discussed. Half-life systematics of the different decay modes detailed in Chaps. 2 and 4 of this volume are also summarized.

  5. Probing α-relaxation with nuclear magnetic resonance echo decay and relaxation: a study on nitrile butadiene rubber.

    PubMed

    Sturniolo, Simone; Pieruccini, Marco; Corti, Maurizio; Rigamonti, Attilio

    2013-01-01

    One dimensional (1)H NMR measurements have been performed to probe slow molecular motions in nitrile butadiene rubber (NBR) around its calorimetric glass transition temperature Tg. The purpose is to show how software aided data analysis can extract meaningful dynamical data from these measurements. Spin-lattice relaxation time, free induction decay (FID) and magic sandwich echo (MSE) measurements have been carried out at different values of the static field, as a function of temperature. It has been evidenced how the efficiency of the MSE signal in reconstructing the original FID exhibits a sudden minimum at a given temperature, with a slight dependence from the measuring frequency. Computer simulations performed with the software SPINEVOLUTION have shown that the minimum in the efficiency reconstruction of the MSE signal corresponds to the average motional frequency taking a value around the inter-proton coupling. The FID signals have been fitted with a truncated form of a newly derived exact correlation function for the transverse magnetization of a dipolar interacting spin pair, which allows one to avoid the restriction of the stationary and Gaussian approximations. A direct estimate of the conformational dynamics on approaching the Tg is obtained, and the results are in agreement with the analysis performed via the MSE reconstruction efficiency. The occurrence of a wide distribution of correlation frequencies for the chains motion, with a Vogel-Fulcher type temperature dependence, is addressed. A route for a fruitful study of the dynamics accompanying the glass transition by a variety of NMR measurements is thus proposed.

  6. β-Decay half-lives and nuclear structure of exotic proton-rich waiting point nuclei under rp-process conditions

    NASA Astrophysics Data System (ADS)

    Nabi, Jameel-Un; Böyükata, Mahmut

    2016-03-01

    We investigate even-even nuclei in the A ∼ 70 mass region within the framework of the proton-neutron quasi-particle random phase approximation (pn-QRPA) and the interacting boson model-1 (IBM-1). Our work includes calculation of the energy spectra and the potential energy surfaces V (β , γ) of Zn, Ge, Se, Kr and Sr nuclei with the same proton and neutron number, N = Z. The parametrization of the IBM-1 Hamiltonian was performed for the calculation of the energy levels in the ground state bands. Geometric shape of the nuclei was predicted by plotting the potential energy surfaces V (β , γ) obtained from the IBM-1 Hamiltonian in the classical limit. The pn-QRPA model was later used to compute half-lives of the neutron-deficient nuclei which were found to be in very good agreement with the measured ones. The pn-QRPA model was also used to calculate the Gamow-Teller strength distributions and was found to be in decent agreement with the measured data. We further calculate the electron capture and positron decay rates for these N = Z waiting point (WP) nuclei in the stellar environment employing the pn-QRPA model. For the rp-process conditions, our total weak rates are within a factor two compared with the Skyrme HF +BCS +QRPA calculation. All calculated electron capture rates are comparable to the competing positron decay rates under rp-process conditions. Our study confirms the finding that electron capture rates form an integral part of the weak rates under rp-process conditions and should not be neglected in the nuclear network calculations.

  7. Modeling nuclear processes by Simulink

    SciTech Connect

    Rashid, Nahrul Khair Alang Md

    2015-04-29

    Modelling and simulation are essential parts in the study of dynamic systems behaviours. In nuclear engineering, modelling and simulation are important to assess the expected results of an experiment before the actual experiment is conducted or in the design of nuclear facilities. In education, modelling can give insight into the dynamic of systems and processes. Most nuclear processes can be described by ordinary or partial differential equations. Efforts expended to solve the equations using analytical or numerical solutions consume time and distract attention from the objectives of modelling itself. This paper presents the use of Simulink, a MATLAB toolbox software that is widely used in control engineering, as a modelling platform for the study of nuclear processes including nuclear reactor behaviours. Starting from the describing equations, Simulink models for heat transfer, radionuclide decay process, delayed neutrons effect, reactor point kinetic equations with delayed neutron groups, and the effect of temperature feedback are used as examples.

  8. Modeling nuclear processes by Simulink

    NASA Astrophysics Data System (ADS)

    Rashid, Nahrul Khair Alang Md

    2015-04-01

    Modelling and simulation are essential parts in the study of dynamic systems behaviours. In nuclear engineering, modelling and simulation are important to assess the expected results of an experiment before the actual experiment is conducted or in the design of nuclear facilities. In education, modelling can give insight into the dynamic of systems and processes. Most nuclear processes can be described by ordinary or partial differential equations. Efforts expended to solve the equations using analytical or numerical solutions consume time and distract attention from the objectives of modelling itself. This paper presents the use of Simulink, a MATLAB toolbox software that is widely used in control engineering, as a modelling platform for the study of nuclear processes including nuclear reactor behaviours. Starting from the describing equations, Simulink models for heat transfer, radionuclide decay process, delayed neutrons effect, reactor point kinetic equations with delayed neutron groups, and the effect of temperature feedback are used as examples.

  9. Messenger RNA transcripts of the hepatocyte nuclear factor-1alpha gene containing premature termination codons are subject to nonsense-mediated decay.

    PubMed

    Harries, Lorna W; Hattersley, Andrew T; Ellard, Sian

    2004-02-01

    Mutations in the hepatocyte nuclear factor-1alpha (HNF-1a) gene cause maturity-onset diabetes of the young (MODY). Approximately 30% of these mutations generate mRNA transcripts harboring premature termination codons (PTCs). Degradation of such transcripts by the nonsense-mediated decay (NMD) pathway has been reported for many genes. To determine whether PTC mutant transcripts of the HNF-1alpha gene elicit NMD, we have developed a novel quantitative RT-PCR assay. We performed quantification of ectopically expressed mutant transcripts relative to normal transcripts in lymphoblastoid cell lines using a coding single nucleotide polymorphism (cSNP) as a marker. The nonsense mutations R171X, I414G415ATCG-->CCA, and P291fsinsC showed reduced mutant mRNA expression to 40% (P = 0.009), <0.01% (P

  10. A nuclear translation-like factor eIF4AIII is recruited to the mRNA during splicing and functions in nonsense-mediated decay.

    PubMed

    Ferraiuolo, Maria A; Lee, Chung-Sheng; Ler, Lian Wee; Hsu, Jeanne L; Costa-Mattioli, Mauro; Luo, Ming-Juan; Reed, Robin; Sonenberg, Nahum

    2004-03-23

    In eukaryotes, a surveillance mechanism known as nonsense-mediated decay (NMD) degrades the mRNA when a premature-termination codon (PTC) is present. NMD requires translation to read the frame of the mRNA and detect the PTC. During pre-mRNA splicing, the exon-exon junction complex (EJC) is recruited to a region 20-24 nt upstream of the exon junction on the mature mRNA. The presence of a PTC upstream from the EJC elicits NMD. Eukaryotic initiation factor 4A (eIF4A) III is a nuclear protein that interacts physically or functionally with translation initiation factors eIF4G and eIF4B, respectively, and shares strikingly high identity with the initiation factors eIF4AI/II. Here we show that siRNA against eIF4AIII, but not against eIF4AI/II, inhibits NMD. Moreover, eIF4AIII, but not eIF4AI, is specifically recruited to the EJC during splicing. The observations that eIF4AIII is loaded onto the mRNA during splicing in the nucleus, has properties related to a translation initiation factor, and functions in NMD raises the possibility that eIF4AIII substitutes for eIF4AI/II during NMD. PMID:15024115

  11. Beta-decay rates

    NASA Astrophysics Data System (ADS)

    Borzov, I. N.

    2006-10-01

    Major astrophysical applications involve a huge number of exotic nuclei. Their beta-decay properties play a crucial role in stellar explosive events. An important effort has been developed in last decades to measure the masses and β-decay properties of very neutron-rich nuclei at radioactive nuclear beam facilities. However, most of them cannot be synthesized in terrestrial laboratories and only theoretical predictions can fill the gap. We will concentrate mainly on the β-decay rates needed for stellar r-process modeling and for performing the RNB experiments. An overview of the microscopic approaches to the β-decay strength function is given. The continuum QRPA approach based on the self-consistent ground state description in the framework of the density functional theory is outlined. For the first time, a systematic study of the total β-decay half-lives and delayed neutron emission probabilities takes into account the Gamow Teller and first-forbidden transitions. Due to the shell configuration effects, the first-forbidden decays have a strong impact on the β-decay characteristics of the r-process relevant nuclei at Z≈28, N>50; Z⩾50, N>82 and Z=60 70, N≈126. Suppression of the delayed neutron emission probability is found in nuclei with the neutron excess bigger than one major shell. The effect originates from the high-energy first-forbidden transitions to the states outside the (Q-B)-window in the daughter nuclei. The performance of existing global models for the nuclides near the r-process paths is critically analyzed and confronted with the recent RIB experiments in the regions of 78Ni, 132Sn and “east” of 208Pb.

  12. Radioactive decay data tables

    SciTech Connect

    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.

  13. Radioactive equilibrium: 99Mo/99mTc decay characteristics.

    PubMed

    Chechev, Valery P; Bé, Marie-Martine

    2014-05-01

    Within the Decay Data Evaluation Project, as an example of a radioactive equilibrium with isomer, the (99)Mo/(99m)Tc equilibrium mixture decay characteristics are examined. The results of a new decay data evaluation are presented for (99)Mo/(99m)Tc decay to nuclear levels in (99)Tc. These evaluated data have been obtained using information published up to 2013.

  14. Constraints on general SU(2)/sub L/ x SU(2)/sub R/ x U(1) electroweak models from nuclear beta decay

    SciTech Connect

    Herczeg, P.

    1986-01-01

    The implications of beta-decay experiments for more general versions of SU(2)/sub L/ x SU(2)/sub R/ x U(1) models are analyzed, including the most general one which allows for CP-violation, unequal left- and right-handed quark mixing angles, and mixing in the leptonic sector. For each scenario, the constraints on the pertinent parameters from beta-decay measurements are compared with the constraints provided on them by other data.

  15. An Experiment on the Decay of 58-Co.

    ERIC Educational Resources Information Center

    Ledingham, K. W. D.; Callaghan, A. H. C.

    1979-01-01

    Describes an experiment which uses a radioactive source, a Sodium Iodide detector, and a simple counting apparatus possessed by most universities and colleges. The decay scheme and the theory of nuclear beta decay are presented. (Author/SA)

  16. 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.

    PubMed

    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)].

  17. A,B,C`s of nuclear science

    SciTech Connect

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

    1995-08-07

    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.

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

    NASA Astrophysics Data System (ADS)

    Chechev, Valery P.; Kuzmenko, Nikolay K.

    2016-02-01

    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.

  19. Seal Out Tooth Decay

    MedlinePlus

    ... Topics > Tooth Decay (Caries) > Seal Out Tooth Decay Seal Out Tooth Decay Main Content What are dental ... back teeth decay so easily? Who should get seal​ants? Should sealants be put on baby teeth? ...

  20. Linguistic Theory and Actual Language.

    ERIC Educational Resources Information Center

    Segerdahl, Par

    1995-01-01

    Examines Noam Chomsky's (1957) discussion of "grammaticalness" and the role of linguistics in the "correct" way of speaking and writing. It is argued that the concern of linguistics with the tools of grammar has resulted in confusion, with the tools becoming mixed up with the actual language, thereby becoming the central element in a metaphysical…

  1. El Observatorio Gemini - Status actual

    NASA Astrophysics Data System (ADS)

    Levato, H.

    Se hace una breve descripción de la situación actual del Observatorio Gemini y de las últimas decisiones del Board para incrementar la eficiencia operativa. Se hace también una breve referencia al uso argentino del observatorio.

  2. ({sup 3}He,t) reaction on the double {beta} decay nucleus {sup 48}Ca and the importance of nuclear matrix elements

    SciTech Connect

    Grewe, E.-W.; Frekers, D.; Rakers, S.; Baeumer, C.; Dohmann, H.; Thies, J.; Adachi, T.; Fujita, Y.; Shimbara, Y.; Botha, N. T.; Fujita, H.; Hatanaka, K.; Nakanishi, K.; Sakemi, Y.; Shimizu, Y.; Tameshige, Y.; Tamii, A.; Negret, A.; Popescu, L.; Neveling, R.

    2007-11-15

    High-resolution ({sup 3}He,t) measurements on the double {beta}-decay ({beta}{beta}) nucleus {sup 48}Ca have been performed at RCNP (Osaka, Japan) to determine Gamow-Teller (GT{sup -}) transitions to the nucleus {sup 48}Sc, which represents the intermediate nucleus in the second-order perturbative description of the {beta}{beta} decay. At a bombarding energy of E{sub {sup 3}He}=420 MeV an excitation energy resolution of 40 keV was achieved. The measurements were performed at two angle positions of the Grand Raiden Spectrometer (GRS): 0 deg. and 2.5 deg. The results of both settings were combined to achieve angular distributions, by which the character of single transitions could be determined. To characterize the different multipoles, theoretical angular distributions for states with J{sup {pi}}=1{sup +},2{sup +},2{sup -}, and 3{sup +} were calculated using the distorted-wave Born approximation (DWBA) Code DW81. The GT{sup -} strength was extracted up to E{sub x}=7 MeV and combined with corresponding GT{sup +} strength deduced from the {sup 48}Ti(d,{sup 2}He){sup 48}Sc data to calculate the low-energy part of the {beta}{beta}-decay matrix element for the {sup 48}Ca 2{nu}{beta}{beta} decay. We show that after applying trivial momentum corrections to the ({sup 3}He,t) spectrum, the two reaction probes (p,n) and ({sup 3}He,t) reveal a spectral response to an impressively high degree of similarity in the region of low momentum transfer.

  3. Spectroscopy of element 115 decay chains

    SciTech Connect

    Rudolph, Dirk; Forsberg, U.; Golubev, P.; Sarmiento, L. G.; Yakushev, A.; Andersson, L.-L.; Di Nitto, A.; Duehllmann, Ch. E.; Gates, J. M.; Gregorich, K. E.; Gross, Carl J; Hessberger, F. P.; Herzberg, R.-D; Khuyagbaatar, J.; Kratz, J. V.; Rykaczewski, Krzysztof Piotr; Schaedel, M.; Aberg, S.; Ackermann, D.; Block, M.; Brand, H.; Carlsson, B. G.; Cox, D.; Derkx, X.; Eberhardt, K.; Even, J.; Fahlander, C.; Gerl, J.; Jaeger, 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.; Thoerle-Pospiech, P.; Torres, T.; Traut, T.; Trautmann, N.; Tuerler, A.; Ward, A.; Ward, D. E.; Wiehl, N.

    2013-01-01

    A high-resolution a, X-ray and -ray coincidence spectroscopy experiment was conducted at the GSI Helmholtzzentrum fu r Schwerionenforschung. Thirty correlated a-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. The data includes first candidates of fingerprinting the decay step Mt --> Bh with characteristic X rays. 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.

  4. [Experimental determination of bacterial decay characteristics in biological wastewater treatment system].

    PubMed

    Hao, Xiao-Di; Zhu, Jing-Yi; Cao, Xiu-Qin; Cao, Ya-Li

    2008-11-01

    The characteristics of cell decay in biological wastewater treatment systems were investigated under aerobic condition, by measuring the decay rate and by determining the death rate with LIVE/DEAD dyeing experiments. It was found that cell decay in biological wastewater treatment systems can be actually described as two parts: decay caused by cell death and decay derived from activity decrease. The experimental results revealed that 60% of cell decay in a nitrifying system was caused by activity decrease and 40% was caused by cell death. In a heterotrophic system, however, activity decrease was responsible for 80% of cell decay, and the other cell decay for 20% was caused by cell death.

  5. Development of JENDL Decay and Fission Yield Data Libraries

    NASA Astrophysics Data System (ADS)

    Katakura, J.

    2014-04-01

    Decay and fission yield data of fission products have been developed for decay heat calculations to constitute one of the special purpose files of JENDL (Japanese Nuclear Data Library). The decay data in the previous JENDL decay data file have been updated based on the data extracted from ENSDF (Evaluated Nuclear Structure Data File) and those by Total Absorption Gamma-ray Spectroscopy (TAGS) measurements reported recently. Fission yield data have also been updated in order to maintain consistency between the decay and yield data files. Decay heat calculations were performed using the updated decay and yield data, and the results were compared with measured decay heat data to demonstrate their applicability. The uncertainties of the calculated results were obtained by sensitivity analyses. The resulting JENDL calculations and their uncertainty were compared with those from the ENDF and JEFF evaluated files.

  6. Gamow-Teller Strength Distributions in {sup 48}Sc by the {sup 48}Ca(p,n) and {sup 48}Ti(n,p) Reactions and Two-Neutrino Double-beta Decay Nuclear Matrix Elements

    SciTech Connect

    Yako, K.; Sasano, M.; Miki, K.; Sakai, H.; Noji, S.; Dozono, M.; Ihara, E.; Wakasa, T.; Frekers, D.; Greenfield, M. B.; Hatanaka, K.; Kato, M.; Matsubara, H.; Okamura, H.; Sakemi, Y.; Tamii, A.; Kawabata, T.; Sakaguchi, S.; Sasamoto, Y.; Shimizu, Y.

    2009-07-03

    The double-differential cross sections for the {sup 48}Ca(p,n) and {sup 48}Ti(n,p) reactions were measured at 300 MeV. A multipole decomposition technique was applied to the spectra to extract the Gamow-Teller (GT) components. The integrated GT strengths up to an excitation energy of 30 MeV in {sup 48}Sc are 15.3+-2.2 and 2.8+-0.3 in the (p,n) and (n,p) spectra, respectively. In the (n,p) spectra additional GT strengths were found above 8 MeV where shell models within the fp shell-model space predict almost no GT strengths, suggesting that the present shell-model description of the nuclear matrix element of the two-neutrino double-beta decay is incomplete.

  7. How People Actually Use Thermostats

    SciTech Connect

    Meier, Alan; Aragon, Cecilia; Hurwitz, Becky; Mujumdar, Dhawal; Peffer, Therese; Perry, Daniel; Pritoni, Marco

    2010-08-15

    Residential thermostats have been a key element in controlling heating and cooling systems for over sixty years. However, today's modern programmable thermostats (PTs) are complicated and difficult for users to understand, leading to errors in operation and wasted energy. Four separate tests of usability were conducted in preparation for a larger study. These tests included personal interviews, an on-line survey, photographing actual thermostat settings, and measurements of ability to accomplish four tasks related to effective use of a PT. The interviews revealed that many occupants used the PT as an on-off switch and most demonstrated little knowledge of how to operate it. The on-line survey found that 89% of the respondents rarely or never used the PT to set a weekday or weekend program. The photographic survey (in low income homes) found that only 30% of the PTs were actually programmed. In the usability test, we found that we could quantify the difference in usability of two PTs as measured in time to accomplish tasks. Users accomplished the tasks in consistently shorter times with the touchscreen unit than with buttons. None of these studies are representative of the entire population of users but, together, they illustrate the importance of improving user interfaces in PTs.

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

    PubMed

    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.

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

    PubMed

    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. PMID:22516599

  10. Nuclear Reaction Data Centers

    SciTech Connect

    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.

  11. Search for solar axion emission from {sup 7}Li and D(p, γ){sup 3}He nuclear decays with the CAST γ-ray calorimeter

    SciTech Connect

    Andriamonje, S.; Aune, S.; Dafni, T.; Ferrer-Ribas, E.; Autiero, D.; Barth, K.; Davenport, M.; Lella, L. Di; Belov, A.; Beltrán, B.; Carmona, J.M.; Cebrián, S.; Bräuninger, H.; Englhauser, J.; Friedrich, P.; Collar, J.I.; Eleftheriadis, C.; Fanourakis, G.; Fischer, H.; Franz, J.; Collaboration: CAST collaboration; and others

    2010-03-01

    We present the results of a search for a high-energy axion emission signal from {sup 7}Li (0.478 MeV) and D(p, γ){sup 3}He (5.5 MeV) nuclear transitions using a low-background γ-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.

  12. Imaging of endogenous messenger RNA splice variants in living cells reveals nuclear retention of transcripts inaccessible to nonsense-mediated decay in Arabidopsis.

    PubMed

    Göhring, Janett; Jacak, Jaroslaw; Barta, Andrea

    2014-02-01

    Alternative splicing (AS) is an important regulatory process that leads to the creation of multiple RNA transcripts from a single gene. Alternative transcripts often carry premature termination codons (PTCs), which trigger nonsense-mediated decay (NMD), a cytoplasmic RNA degradation pathway. However, intron retention, the most prevalent AS event in plants, often leads to PTC-carrying splice variants that are insensitive to NMD; this led us to question the fate of these special RNA variants. Here, we present an innovative approach to monitor and characterize endogenous mRNA splice variants within living plant cells. This method combines standard confocal laser scanning microscopy for molecular beacon detection with a robust statistical pipeline for sample comparison. We demonstrate this technique on the localization of NMD-insensitive splice variants of two Arabidopsis thaliana genes, RS2Z33 and the SEF factor. The experiments reveal that these intron-containing splice variants remain within the nucleus, which allows them to escape the NMD machinery. Moreover, fluorescence recovery after photobleaching experiments in the nucleoplasm show a decreased mobility of intron-retained mRNAs compared with fully spliced RNAs. In addition, differences in mobility were observed for an mRNA dependent on its origin from an intron-free or an intron-containing gene.

  13. The actual goals of geoethics

    NASA Astrophysics Data System (ADS)

    Nemec, Vaclav

    2014-05-01

    The most actual goals of geoethics have been formulated as results of the International Conference on Geoethics (October 2013) held at the geoethics birth-place Pribram (Czech Republic): In the sphere of education and public enlightenment an appropriate needed minimum know how of Earth sciences should be intensively promoted together with cultivating ethical way of thinking and acting for the sustainable well-being of the society. The actual activities of the Intergovernmental Panel of Climate Changes are not sustainable with the existing knowledge of the Earth sciences (as presented in the results of the 33rd and 34th International Geological Congresses). This knowledge should be incorporated into any further work of the IPCC. In the sphere of legislation in a large international co-operation following steps are needed: - to re-formulate the term of a "false alarm" and its legal consequences, - to demand very consequently the needed evaluation of existing risks, - to solve problems of rights of individuals and minorities in cases of the optimum use of mineral resources and of the optimum protection of the local population against emergency dangers and disasters; common good (well-being) must be considered as the priority when solving ethical dilemmas. The precaution principle should be applied in any decision making process. Earth scientists presenting their expert opinions are not exempted from civil, administrative or even criminal liabilities. Details must be established by national law and jurisprudence. The well known case of the L'Aquila earthquake (2009) should serve as a serious warning because of the proven misuse of geoethics for protecting top Italian seismologists responsible and sentenced for their inadequate superficial behaviour causing lot of human victims. Another recent scandal with the Himalayan fossil fraud will be also documented. A support is needed for any effort to analyze and to disclose the problems of the deformation of the contemporary

  14. Spectroscopy of element 115 decay chains.

    PubMed

    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.

  15. β -decay study of 94Kr

    NASA Astrophysics Data System (ADS)

    Miernik, K.; Rykaczewski, K. P.; Grzywacz, R.; Gross, C. J.; Madurga, M.; Miller, D.; Stracener, D. W.; Batchelder, J. C.; Brewer, N. T.; Cartegni, L.; Fijałkowska, A.; Karny, M.; Korgul, A.; Królas, W.; Mazzocchi, C.; Mendez, A. J., II; Padgett, S. W.; Paulauskas, S. V.; Winger, J. A.; Wolińska-Cichocka, M.; Zganjar, E. F.

    2016-08-01

    β decay of neutron-rich nuclide 94Kr was reinvestigated by means of a high resolution on-line mass separator and β -γ spectroscopy. In total 22 γ -ray transitions were assigned to the decay of 94Kr, and a new isomeric state was identified. The new information allows us to build detailed levels systematics in a chain of odd-odd rubidium isotopes and draw conclusions on nuclear structure for some of the observed states. The discussed level structure affects the evolution of β -decay half-lives for neutron-rich selenium, krypton, and strontium isotopes.

  16. Spectroscopy of element 115 decay chains.

    PubMed

    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. PMID:24074079

  17. Interatomic Coulombic decay in nanodroplets

    NASA Astrophysics Data System (ADS)

    Sisourat, Nicolas

    2014-05-01

    Interatomic (molecular) Coulombic decay (ICD) is an ultrafast non-radiative electronic decay process for excited atoms or molecules embedded in a chemical environment. Via ICD, the excited system can get rid of the excess energy, which is transferred to one of the neighbors and ionize it. ICD produces two charged particles next to each other and thus leads to Coulomb explosion. Kinetic energy distribution of the ionic fragments gives information on the dynamics of the decay process. From the theoretical point of view general quantum mechanical equations for describing the decay processes and the subsequent fragmentations are known but are only applicable for rather small systems. During the presentation, a semiclassical approach for modeling ICD and the subsequent fragmentations will be presented. This approach involves a classical treatment for the nuclear motion while retaining a quantum description for the electron dynamics. Such approach has low computational costs and can be used to study much larger systems. Comparison of the results from semiclassical and from quantum mechanical calculations will be shown for simple systems, demonstrating the good performance of the semiclassical method. Results on ICD in nanodroplets will finally be reported.

  18. Overview of nuclear data

    SciTech Connect

    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.

  19. Computer code for double beta decay QRPA based calculations

    SciTech Connect

    Barbero, C. A.; Mariano, A.; Krmpotić, F.; Samana, A. R.; Ferreira, V. dos Santos; Bertulani, C. A.

    2014-11-11

    The computer code developed by our group some years ago for the evaluation of nuclear matrix elements, within the QRPA and PQRPA nuclear structure models, involved in neutrino-nucleus reactions, muon capture and β{sup ±} processes, is extended to include also the nuclear double beta decay.

  20. Evidence for the decay

    NASA Astrophysics Data System (ADS)

    Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Cartelle, P. Alvarez; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreassen, R.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Gutierrez, O. Aquines; Archilli, F.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Balagura, V.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Bauer, Th.; Bay, A.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Belogurov, S.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bettler, M.-O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Bird, T.; Bizzeti, A.; Bjørnstad, P. M.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borgia, A.; Borsato, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Brambach, T.; van den Brand, J.; Bressieux, J.; Brett, D.; Britsch, M.; Britton, T.; Brook, N. H.; Brown, H.; Bursche, A.; Busetto, G.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Callot, O.; Calvi, M.; Gomez, M. Calvo; Camboni, A.; Campana, P.; Perez, D. Campora; Caponio, F.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carranza-Mejia, H.; Carson, L.; Akiba, K. Carvalho; Casse, G.; Cassina, L.; Garcia, L. Castillo; Cattaneo, M.; Cauet, Ch.; Cenci, R.; Charles, M.; Charpentier, Ph.; Cheung, S.-F.; Chiapolini, N.; Chrzaszcz, M.; Ciba, K.; Vidal, X. Cid; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coca, C.; Coco, V.; Cogan, J.; Cogneras, E.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Counts, I.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Torres, M. Cruz; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Dalseno, J.; David, P.; David, P. N. Y.; Davis, A.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Silva, W.; De Simone, P.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Déléage, N.; Derkach, D.; Deschamps, O.; Dettori, F.; Di Canto, A.; Dijkstra, H.; Donleavy, S.; Dordei, F.; Dorigo, M.; Suárez, A. Dosil; Dossett, D.; Dovbnya, A.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Esen, S.; Falabella, A.; Färber, C.; Farinelli, C.; Farley, N.; Farry, S.; Ferguson, D.; Albor, V. Fernandez; Rodrigues, F. Ferreira; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Torreira, A. Gallas; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Garofoli, J.; Tico, J. Garra; Garrido, L.; Gaspar, C.; Gauld, R.; Gavardi, L.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianelle, A.; Giani', S.; Gibson, V.; Giubega, L.; Gligorov, V. V.; Göbel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gordon, H.; Gotti, C.; Gándara, M. Grabalosa; Diaz, R. Graciani; Cardoso, L. A. Granado; Graugés, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griffith, P.; Grillo, L.; Grünberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Hafkenscheid, T. W.; Haines, S. C.; Hall, S.; Hamilton, B.; Hampson, T.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; Hartmann, T.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; Morata, J. A. Hernando; van Herwijnen, E.; Heß, M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Hunt, P.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jans, E.; Jaton, P.; Jawahery, A.; Jezabek, M.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kaballo, M.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Kelsey, M.; Kenyon, I. R.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Korolev, M.; Kozlinskiy, A.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kucharczyk, M.; Kudryavtsev, V.; Kurek, K.; Kvaratskheliya, T.; La Thi, V. N.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lambert, R. W.; Lanciotti, E.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J.-P.; Lefèvre, R.; Leflat, A.; Lefrançois, J.; Leo, S.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Liles, M.; Lindner, R.; Linn, C.; Lionetto, F.; Liu, B.; Liu, G.; Lohn, S.; Longstaff, I.; Lopes, J. H.; Lopez-March, N.; Lowdon, P.; Lu, H.; Lucchesi, D.; Luo, H.; Luppi, E.; Lupton, O.; Machefert, F.; Machikhiliyan, I. V.; Maciuc, F.; Maev, O.; Malde, S.; Manca, G.; Mancinelli, G.; Manzali, M.; Maratas, J.; Marchand, J. F.; Marconi, U.; Benito, C. Marin; Marino, P.; Märki, R.; Marks, J.; Martellotti, G.; Martens, A.; Sánchez, A. Martín; Martinelli, M.; Santos, D. Martinez; Vidal, F. Martinez; Tostes, D. Martins; Massafferri, A.; Matev, R.; Mathe, Z.; Matteuzzi, C.; Mazurov, A.; McCann, M.; McCarthy, J.; McNab, A.; McNulty, R.; McSkelly, B.; Meadows, B.; Meier, F.; Meissner, M.; Merk, M.; Milanes, D. A.; Minard, M.-N.; Rodriguez, J. Molina; Monteil, S.; Moran, D.; Morandin, M.; Morawski, P.; Mordà, A.; Morello, M. J.; Moron, J.; Mountain, R.; Muheim, F.; Müller, K.; Muresan, R.; Muster, B.; Naik, P.; Nakada, T.; Nandakumar, R.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen, T. D.; Nguyen-Mau, C.; Nicol, M.; Niess, V.; Niet, R.; Nikitin, N.; Nikodem, T.; Novoselov, A.; Oblakowska-Mucha, A.; Obraztsov, V.; Oggero, S.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Onderwater, G.; Orlandea, M.; Goicochea, J. M. Otalora; Owen, P.; Oyanguren, A.; Pal, B. K.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L.; Parkes, C.; Parkinson, C. J.; Passaleva, G.; Patel, G. D.; Patel, M.; Patrignani, C.; Alvarez, A. Pazos; Pearce, A.; Pellegrino, A.; Altarelli, M. Pepe; Perazzini, S.; Trigo, E. Perez; Perret, P.; Perrin-Terrin, M.; Pescatore, L.; Pesen, E.; Petridis, K.; Petrolini, A.; Olloqui, E. Picatoste; Pietrzyk, B.; Pilař, T.; Pinci, D.; Pistone, A.; Playfer, S.; Casasus, M. Plo; Polci, F.; Poluektov, A.; Polycarpo, E.; Popov, A.; Popov, D.; Popovici, B.; Potterat, C.; Powell, A.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Navarro, A. Puig; Punzi, G.; Qian, W.; Rachwal, B.; Rademacker, J. H.; Rakotomiaramanana, B.; Rama, M.; Rangel, M. S.; Raniuk, I.; Rauschmayr, N.; Raven, G.; Reichert, S.; Reid, M. M.; dos Reis, A. C.; Ricciardi, S.; Richards, A.; Rinnert, K.; Molina, V. Rives; Romero, D. A. Roa; Robbe, P.; Roberts, D. A.; Rodrigues, A. B.; Rodrigues, E.; Perez, P. Rodriguez; Roiser, S.; Romanovsky, V.; Vidal, A. Romero; Rotondo, M.; Rouvinet, J.; Ruf, T.; Ruffini, F.; Ruiz, H.; Valls, P. Ruiz; Sabatino, G.; Silva, J. J. Saborido; Sagidova, N.; Sail, P.; Saitta, B.; Guimaraes, V. Salustino; Sedes, B. Sanmartin; Santacesaria, R.; Rios, C. Santamarina; Santovetti, E.; Sapunov, M.; Sarti, A.; Satriano, C.; Satta, A.; Savrie, M.; Savrina, D.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmidt, B.; Schneider, O.; Schopper, A.; Schune, M.-H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Seco, M.; Semennikov, A.; Senderowska, K.; Sepp, I.; Serra, N.; Serrano, J.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, O.; Shevchenko, V.; Shires, A.; Sidorov, F.; Coutinho, R. Silva; Simi, G.; Sirendi, M.; Skidmore, N.; Skwarnicki, T.; Smith, N. A.; Smith, E.; Smith, E.; Smith, J.; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Soomro, F.; Souza, D.; De Paula, B. Souza; Spaan, B.; Sparkes, A.; Spinella, F.; Spradlin, P.; Stagni, F.; Stahl, S.; Steinkamp, O.; Stevenson, S.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Stroili, R.; Subbiah, V. K.; Sun, L.; Sutcliffe, W.; Swientek, K.; Swientek, S.; Syropoulos, V.; Szczekowski, M.; Szczypka, P.; Szilard, D.; Szumlak, T.; T'Jampens, S.; Teklishyn, M.; Tellarini, G.; Teubert, F.; Thomas, C.; Thomas, E.; van Tilburg, J.; Tisserand, V.; Tobin, M.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Tran, M. T.; Tresch, M.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Garcia, M. Ubeda; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vagnoni, V.; Valenti, G.; Vallier, A.; Gomez, R. Vazquez; Regueiro, P. Vazquez; Sierra, C. Vázquez; Vecchi, S.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Vesterinen, M.; Viaud, B.; Vieira, D.; Vilasis-Cardona, X.; Vollhardt, A.; Volyanskyy, D.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voß, C.; Voss, H.; de Vries, J. A.; Waldi, R.; Wallace, C.; Wallace, R.; Wandernoth, S.; Wang, J.; Ward, D. R.; Watson, N. K.; Websdale, D.; Whitehead, M.; Wicht, J.; Wiedner, D.; Wilkinson, G.; Williams, M. P.; Williams, M.; Wilson, F. F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wright, S.; Wu, S.; Wyllie, K.; Xie, Y.; Xing, Z.; Yang, Z.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zavertyaev, M.; Zhang, F.; Zhang, L.; Zhang, W. C.; Zhang, Y.; Zhelezov, A.; Zhokhov, A.; Zhong, L.; Zvyagin, A.

    2014-05-01

    Evidence is presented for the decay using proton-proton collision data, corresponding to an integrated luminosity of 3 fb-1, collected with the LHCb detector. A signal yield of 32 ± 8 decays is found with a significance of 4.5 standard deviations. The ratio of the branching fraction of the decay to that of the decay is measured to be where the first uncertainty is statistical and the second is systematic. [Figure not available: see fulltext.

  1. Distinguishing activity decay and cell death from bacterial decay for two types of methanogens.

    PubMed

    Hao, Xiaodi; Cai, Zhengqing; Fu, Kunming; Zhao, Dongye

    2012-03-15

    As bacterial decay consists of cell death and activity decay, and the corresponding information about AOB/NOB, OHO, PAOs and GAOs has been experimentally acquired, another functional type of bacteria in biological wastewater treatment, methanogens, remains to be investigated, to gather the same information, which is extremely important for such bacteria with low growth rates. With successfully selection and enrichment of both aceticlastic and hydrogenotrophic methanogens, and by means of measuring specific methane activity (SMA) and hydrogen consumption rate (HCR), a series of decay experiments and molecular techniques such as FISH verification and LIVE/DEAD staining revealed, identified and calculated the decay and death rates of both aceticlastic and hydrogenotrophic methanogens respectively. The results indicated that the decay rates of aceticlastic and hydrogenotrophic methanogens were 0.070 and 0.034 d(-1) respectively, and the death rates were thus calculated at 0.022 and 0.016 d(-1) respectively. For this reason, cell deaths were only responsible for 31% and 47% of the total bacterial decay of aceticlastic and hydrogenotrophic methanogens, and activity decays actually contributed significantly to the total bacterial decay, respectively at 69% and 53%.

  2. Correlations and the neutrinoless double beta decay

    SciTech Connect

    Menendez, J.; Poves, A.; Caurier, E.; Nowacki, F.

    2009-11-09

    We explore the influence of the deformation on the nuclear matrix elements of the neutrinoless double beta decay (NME), concluding that the difference in deformation -or more generally on the amount of quadrupole correlations- between parent and grand daughter nuclei quenchs strongly the decay. We discuss how varies the nuclear matrix element of {sup 76}Ge decay when the wave functions of the two nuclei involved in the transition are constrained to reproduce the experimental occupancies. In the Interacting Shell Model description the value of the NME is enhanced about 15% compared to previous calculations, whereas in the QRPA the NME's are reduced by 20%-30%, thus, the discrepancies between both approaches diminish.

  3. Nuclear physics: a short course

    SciTech Connect

    Hirsch, Jorge G.

    2010-09-10

    Basic properties of atomic nuclei are reviewed. Starting with the energy and length scales for microscopic processes, we go through the charge density inside the nucleus, nuclear masses and abundances, and nuclear decays. The Liquid Drop Model is presented along with some extensions. Microscopic models are introduced, with emphasis in the shell model. Alpha, beta and gamma decays are commented with some detail, including the symmetry laws which govern these decays.

  4. Nuclear analytical chemistry

    SciTech Connect

    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.

  5. Rare Decays at LHCb

    NASA Astrophysics Data System (ADS)

    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.

  6. Thermal and statistical properties of nuclei and nuclear systems

    SciTech Connect

    Moretto, L.G.; Wozniak, G.J.

    1989-07-01

    The term statistical decay, statistical or thermodynamic equilibrium, thermalization, temperature, etc., have been used in nuclear physics since the introduction of the compound nucleus (CN) concept, and they are still used, perhaps even more frequently, in the context of intermediate- and high-energy heavy-ion reactions. Unfortunately, the increased popularity of these terms has not made them any clearer, and more often than not one encounters sweeping statements about the alleged statisticity of a nuclear process where the statistical'' connotation is a more apt description of the state of the speaker's mind than of the nuclear reaction. It is our goal, in this short set of lectures, to set at least some ideas straight on this broad and beautiful subject, on the one hand by clarifying some fundamental concepts, on the other by presenting some interesting applications to actual physical cases. 74 refs., 38 figs.

  7. Effective Majorana neutrino decay

    NASA Astrophysics Data System (ADS)

    Duarte, Lucía; Romero, Ismael; Peressutti, Javier; Sampayo, Oscar A.

    2016-08-01

    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.

  8. Nuclear Fuel Reprocessing

    SciTech Connect

    Harold F. McFarlane; Terry Todd

    2013-11-01

    Reprocessing is essential to closing nuclear fuel cycle. Natural uranium contains only 0.7 percent 235U, the fissile (see glossary for technical terms) isotope that produces most of the fission energy in a nuclear power plant. Prior to being used in commercial nuclear fuel, uranium is typically enriched to 3–5% in 235U. If the enrichment process discards depleted uranium at 0.2 percent 235U, it takes more than seven tonnes of uranium feed to produce one tonne of 4%-enriched uranium. Nuclear fuel discharged at the end of its economic lifetime contains less one percent 235U, but still more than the natural ore. Less than one percent of the uranium that enters the fuel cycle is actually used in a single pass through the reactor. The other naturally occurring isotope, 238U, directly contributes in a minor way to power generation. However, its main role is to transmute into plutoniumby neutron capture and subsequent radioactive decay of unstable uraniumand neptuniumisotopes. 239Pu and 241Pu are fissile isotopes that produce more than 40% of the fission energy in commercially deployed reactors. It is recovery of the plutonium (and to a lesser extent the uranium) for use in recycled nuclear fuel that has been the primary focus of commercial reprocessing. Uraniumtargets irradiated in special purpose reactors are also reprocessed to obtain the fission product 99Mo, the parent isotope of technetium, which is widely used inmedical procedures. Among the fission products, recovery of such expensive metals as platinum and rhodium is technically achievable, but not economically viable in current market and regulatory conditions. During the past 60 years, many different techniques for reprocessing used nuclear fuel have been proposed and tested in the laboratory. However, commercial reprocessing has been implemented along a single line of aqueous solvent extraction technology called plutonium uranium reduction extraction process (PUREX). Similarly, hundreds of types of reactor

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

    SciTech Connect

    Ito, Takeyasu M.

    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. Observation of Ground-state Two-neutron Decay

    NASA Astrophysics Data System (ADS)

    Thoennessen, M.; Kohley, Z.; Spyrou, A.; Lunderberg, E.; DeYoung, P. A.; Attanayake, H.; Baumann, T.; Bazin, D.; Brown, B. A.; Christian, G.; Divaratne, D.; Grimes, S. M.; Haagsma, A.; Finck, J. E.; Frank, N.; Luther, B.; Mosby, S.; Nagi, T.; Peaslee, G. F.; Peters, W. A.; Schiller, A.; Smith, J. K.; Snyder, J.; Strongman, M.; Volya, A.

    Neutron decay spectroscopy has become a successful tool to explore nuclear properties of nuclei with the largest neutron-to-proton ratios. Resonances in nuclei located beyond the neutron dripline are accessible by kinematic reconstruction of the decay products. The development of two-neutron detection capabilities of the Modular Neutron Array (MoNA) at NSCL has opened up the possibility to search for unbound nuclei which decay by the emission of two neutrons. Specifically this exotic decay mode was observed in 16Be and 26O.

  11. Neutrinos in Nuclear Physics

    SciTech Connect

    McKeown, Bob

    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.

  12. Fundamental processes in the interacting boson model: 0{nu}{beta}{beta} decay

    SciTech Connect

    Iachello, F.; Barea, J.

    2011-05-06

    A program to calculate nuclear matrix elements for fundamental processes in the interacting boson model has been initiated. Results for the nuclear matrix elements in neutrinoless double beta decay 0{nu}{beta}{beta} are presented.

  13. Nuclear Data Sheets for A = 52

    SciTech Connect

    Dong, Yang; Junde, Huo

    2015-09-15

    The nuclear structure data belonging to all nuclei with mass number A=52 have been compiled and evaluated using experimental nuclear reaction data and decay data available before July 10, 2015. This evaluaton supersedes the previous publication for this msss chain (2007Hu08, Nuclear Data Sheets 108, 773 (2007)). The data for the ε decay of {sup 52}Co (104 ms) and the ε decay of {sup 52}Ni (40.8 ms) are both incomplete, so new studies would be useful.

  14. Mesonic Decay of Charm Hypernuclei Λc+

    NASA Astrophysics Data System (ADS)

    Ghosh, Sabyasachi; Fontoura, Carlos E.; Krein, Gastão

    2016-03-01

    Λc+ hypernuclei are expected to have binding energies and other properties similar to those of strange hypernuclei in view of the similarity between the quark structures of the strange and charmed hyperons, namely Λ(uds) and Λc+(udc). One striking difference however occurs in their mesonic decays, as there is almost no Pauli blocking in the nucleonic decay of a charm hypernucleus because the final-state nucleons leave the nucleus at high energies. The nuclear medium nevertheless affects the mesonic decays of charm hypernucleus because the nuclear mean fields modify the masses of the charm hyperon. In the present communication we present results of a first investigation of the effects of finite baryon density on different weak mesonic decay channels of the Λc+ baryon. We found a non-negligible reduction of the decay widths as compared to their vacuum values.

  15. Neutrinoless double beta decay and neutrino masses

    SciTech Connect

    Duerr, Michael

    2012-07-27

    Neutrinoless double beta decay (0{nu}{beta}{beta}) is a promising test for lepton number violating physics beyond the standard model (SM) of particle physics. There is a deep connection between this decay and the phenomenon of neutrino masses. In particular, we will discuss the relation between 0{nu}{beta}{beta} and Majorana neutrino masses provided by the so-called Schechter-Valle theorem in a quantitative way. Furthermore, we will present an experimental cross check to discriminate 0{nu}{beta}{beta} from unknown nuclear background using only one isotope, i.e., within one experiment.

  16. Self-Actualization, Liberalism, and Humanistic Education.

    ERIC Educational Resources Information Center

    Porter, Charles Mack

    1979-01-01

    The relationship between personality factors and political orientation has long been of interest to psychologists. This study tests the hypothesis that there is no significant relationship between self-actualization and liberalism-conservatism. The hypothesis is supported. (Author)

  17. Tuning fork decay.

    PubMed

    Miller, G W

    1979-03-01

    Tuning fork tests are used routinely by many otologists. A different group of otologists find the tests inconsistent and unreliable. This controversy has probably developed because the audiometer has replaced the tuning fork in hearing measurement. As a result, the art of use of the tuning fork is poorly learned. This study examines decay, one of the physical parameters of tuning forks. Measurements of acoustic (sound wave) and vibration (stem movement) decay were made. Alteration in decay due to pressure changes on the fork stem were studied. Acoustic signals were generated in an anechoic chamber. Vibration measurements were obtained using an artificial mastoid. Analysis of the signals was accomplished by a system of amplifiers, filters, tape recorders, and a graphic recorder. Tuning fork sound decay is a property of the instrument which occurs every time the fork is struck. The decay is a constant in decibels per second. The acoustic mode and the vibration mode decay at similar rates for the same fork. The strike frequency (a higher frequency than the fundamental produced when the fork is struck) also has a constant decay rate in decibels per second, and it is reported here for the first time. Force of 800 gm. and less applied to the bottom of the stem in vibration measurement caused minimal decay constant changes. When the physical parameters of the tuning fork (including this information on damping) are fully studied, tuning fork testing should become more of a science and less of an art.

  18. Radioactive Decay - An Analog.

    ERIC Educational Resources Information Center

    McGeachy, Frank

    1988-01-01

    Presents an analog of radioactive decay that allows the student to grasp the concept of half life and the exponential nature of the decay process. The analog is devised to use small, colored, plastic poker chips or counters. Provides the typical data and a graph which supports the analog. (YP)

  19. Hypernuclear Weak Decays

    NASA Astrophysics Data System (ADS)

    Itonaga, K.; Motoba, T.

    The recent theoretical studies of Lambda-hypernuclear weak decaysof the nonmesonic and pi-mesonic ones are developed with the aim to disclose the link between the experimental decay observables and the underlying basic weak decay interactions and the weak decay mechanisms. The expressions of the nonmesonic decay rates Gamma_{nm} and the decay asymmetry parameter alpha_1 of protons from the polarized hypernuclei are presented in the shell model framework. We then introduce the meson theoretical Lambda N -> NN interactions which include the one-meson exchanges, the correlated-2pi exchanges, and the chiral-pair-meson exchanges. The features of meson exchange potentials and their roles on the nonmesonic decays are discussed. With the adoption of the pi + 2pi/rho + 2pi/sigma + omega + K + rhopi/a_1 + sigmapi/a_1 exchange potentials, we have carried out the systematic calculations of the nonmesonic decay observables for light-to-heavy hypernuclei. The present model can account for the available experimental data of the decay rates, Gamma_n/Gamma_p ratios, and the intrinsic asymmetry parameters alpha_Lambda (alpha_Lambda is related to alpha_1) of emitted protons well and consistently within the error bars. The hypernuclear lifetimes are evaluated by converting the total weak decay rates Gamma_{tot} = Gamma_pi + Gamma_{nm} to tau, which exhibit saturation property for the hypernuclear mass A ≥ 30 and agree grossly well with experimental data for the mass range from light to heavy hypernuclei except for the very light ones. Future extensions of the model and the remaining problems are also mentioned. The pi-mesonic weak processes are briefly surveyed, and the calculations and predictions are compared and confirmed by the recent high precision FINUDA pi-mesonic decay data. This shows that the theoretical basis seems to be firmly grounded.

  20. Axions from wall decay

    SciTech Connect

    Chang, S; Hagmann, C; Sikivie, P

    2001-01-08

    The authors discuss the decay of axion walls bounded by strings and present numerical simulations of the decay process. In these simulations, the decay happens immediately, in a time scale of order the light travel time, and the average energy of the radiated axions is {approx_equal} 7m{sub a} for v{sub a}/m{sub a} {approx_equal} 500. is found to increase approximately linearly with ln(v{sub a}/m{sub a}). Extrapolation of this behavior yields {approx_equal} 60 m{sub a} in axion models of interest.

  1. Modulated curvaton decay

    SciTech Connect

    Assadullahi, Hooshyar; Wands, David; Firouzjahi, Hassan; Namjoo, Mohammad Hossein E-mail: firouz@mail.ipm.ir E-mail: david.wands@port.ac.uk

    2013-03-01

    We study primordial density perturbations generated by the late decay of a curvaton field whose decay rate may be modulated by the local value of another isocurvature field, analogous to models of modulated reheating at the end of inflation. We calculate the primordial density perturbation and its local-type non-Gaussianity using the sudden-decay approximation for the curvaton field, recovering standard curvaton and modulated reheating results as limiting cases. We verify the Suyama-Yamaguchi inequality between bispectrum and trispectrum parameters for the primordial density field generated by multiple field fluctuations, and find conditions for the bound to be saturated.

  2. Realizing actual feedback control of complex network

    NASA Astrophysics Data System (ADS)

    Tu, Chengyi; Cheng, Yuhua

    2014-06-01

    In this paper, we present the concept of feedbackability and how to identify the Minimum Feedbackability Set of an arbitrary complex directed network. Furthermore, we design an estimator and a feedback controller accessing one MFS to realize actual feedback control, i.e. control the system to our desired state according to the estimated system internal state from the output of estimator. Last but not least, we perform numerical simulations of a small linear time-invariant dynamics network and a real simple food network to verify the theoretical results. The framework presented here could make an arbitrary complex directed network realize actual feedback control and deepen our understanding of complex systems.

  3. Fast analysis of radionuclide decay chain migration

    NASA Astrophysics Data System (ADS)

    Chen, J. S.; Liang, C. P.; Liu, C. W.; Li, L.

    2014-12-01

    A novel tool for rapidly predicting the long-term plume behavior of an arbitrary length radionuclide decay chain is presented in this study. This fast tool is achieved based on generalized analytical solutions in compact format derived for a set of two-dimensional advection-dispersion equations coupled with sequential first-order decay reactions in groundwater system. The performance of the developed tool is evaluated by a numerical model using a Laplace transform finite difference scheme. The results of performance evaluation indicate that the developed model is robust and accurate. The developed model is then used to fast understand the transport behavior of a four-member radionuclide decay chain. Results show that the plume extents and concentration levels of any target radionuclide are very sensitive to longitudinal, transverse dispersion, decay rate constant and retardation factor. The developed model are useful tools for rapidly 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.

  4. Nuclear Data Sheets for A = 203

    SciTech Connect

    Kondev, F.G.

    2005-05-01

    Evaluated nuclear structure and decay data for all nuclei within the A = 203 mass chain are presented. This work supersedes the earlier evaluation by S. Rab (1993Ra11), published in Nuclear Data Sheets 70, 173 (1993)

  5. Nuclear Data Sheets for A = 202

    SciTech Connect

    Zhu, S.; Kondev, F.G.

    2008-03-15

    Evaluated nuclear structure and decay data for all nuclei within the A = 202 mass chain are presented. This work supersedes the earlier evaluation by M.R. Schmorak (1997Sc07), published in Nuclear Data Sheets80, 647 (1997)

  6. RARE KAON DECAYS.

    SciTech Connect

    LITTENBERG, L.

    2005-07-19

    Lepton flavor violation (LFV) experiments have probed sensitivities corresponding to mass scales of well over 100 TeV, making life difficult for models predicting accessible LFV in kaon decay and discouraging new dedicated experiments of this type.

  7. Radiative B Decays

    SciTech Connect

    Bard, D.; /Imperial Coll., London

    2011-11-23

    I discuss recent results in radiative B decays from the Belle and BaBar collaborations. I report new measurements of the decay rate and CP asymmetries in b {yields} s{gamma} and b {yields} d{gamma} decays, and measurements of the photon spectrum in b {yields} s{gamma}. Radiative penguin decays are flavour changing neutral currents which do not occur at tree level in the standard model (SM), but must proceed via one loop or higher order diagrams. These transitions are therefore suppressed in the SM, but offer access to poorlyknown SM parameters and are also a sensitive probe of new physics. In the SM, the rate is dominated by the top quark contribution to the loop, but non-SM particles could also contribute with a size comparable to leading SM contributions. The new physics effects are potentially large which makes them theoretically very interesting, but due to their small branching fractions they are typically experimentally challenging.

  8. Charmless B Decays

    SciTech Connect

    Gradl, Wolfgang; /Edinburgh U.

    2007-03-06

    Rare charmless hadronic B decays are a good testing ground for the standard model. The dominant amplitudes contributing to this class of B decays are CKM suppressed tree diagrams and b {yields} s or b {yields} d loop diagrams (''penguins''). These decays can be used to study interfering standard model (SM) amplitudes and CP violation. They are sensitive to the presence of new particles in the loops, and they provide valuable information to constrain theoretical models of B decays. The B factories BABAR at SLAC and Belle at KEK produce B mesons in the reaction e{sup +}e{sup -} {yields} {Upsilon}(4S) {yields} B{bar B}. So far they have collected integrated luminosities of about 406 fb{sup -1} and 600 fb{sup -1}, respectively. The results presented here are based on subsets of about 200-500 fb{sup -1} and are preliminary unless a journal reference is given.

  9. Open Flavor Strong Decays

    NASA Astrophysics Data System (ADS)

    García-Tecocoatzi, H.; Bijker, R.; Ferretti, J.; Galatà, G.; Santopinto, E.

    2016-10-01

    In this contribution, we discuss the results of a QM calculation of the open-flavor strong decays of **** light nucleon resonances. These are the results of a recent calculation, where we used a modified ^3P_0 model for the amplitudes and the U(7) algebraic model and the hypercentral quark model to predict the baryon spectrum. The decay amplitudes are compared with the existing experimental data.

  10. Beyond low beta-decay Q values

    SciTech Connect

    Mustonen, M. T.; Suhonen, J.

    2010-11-24

    Beta decays with low Q values can be utilized in the quest to determine the neutrino mass scale. This is being realized in two experiments, KATRIN and MARE, using tritium and {sup 187}Re, respectively. The beta-decay of {sup 187}Re had the lowest known Q value until 2005, when the beta decay of {sup 115}In to the first excited state of {sup 115}Sn was discovered in Gran Sasso underground laboratory. Last year two independent ion trap measurements confirmed that this decay breaks the former record by an order of magnitude.Our theoretical study on this tiny decay channel complemented the experimental effort by the JYFLTRAP group in Finland and HADES underground laboratory in Belgium. A significant discrepancy between the experimental and theoretical results was found. This might be explained by various atomic contributions known to grow larger as the Q value decreases. However, the traditional recipes for taking these effects into account break down on this new ultra-low Q value regime, providing new challenges for theorists on the borderline between nuclear and atomic physics.

  11. Developing Human Resources through Actualizing Human Potential

    ERIC Educational Resources Information Center

    Clarken, Rodney H.

    2012-01-01

    The key to human resource development is in actualizing individual and collective thinking, feeling and choosing potentials related to our minds, hearts and wills respectively. These capacities and faculties must be balanced and regulated according to the standards of truth, love and justice for individual, community and institutional development,…

  12. [Actual diet of patients with gastrointestinal diseases].

    PubMed

    Loranskaia, T I; Shakhovskaia, A K; Pavliuchkova, M S

    2000-01-01

    The study of actual nutrition of patients with erosive-ulcerative lesions in the gastroduodenal zone and of patients with operated ulcer has revealed defects in intake of essential nutrients by these patients: overeating of animal fat and refined carbohydrates, deficiency of oil, vitamins A, B2, C, D and food fibers.

  13. Humanistic Education and Self-Actualization Theory.

    ERIC Educational Resources Information Center

    Farmer, Rod

    1984-01-01

    Stresses the need for theoretical justification for the development of humanistic education programs in today's schools. Explores Abraham Maslow's hierarchy of needs and theory of self-actualization. Argues that Maslow's theory may be the best available for educators concerned with educating the whole child. (JHZ)

  14. Group Counseling for Self-Actualization.

    ERIC Educational Resources Information Center

    Streich, William H.; Keeler, Douglas J.

    Self-concept, creativity, growth orientation, an integrated value system, and receptiveness to new experiences are considered to be crucial variables to the self-actualization process. A regular, year-long group counseling program was conducted with 85 randomly selected gifted secondary students in the Farmington, Connecticut Public Schools. A…

  15. Teenagers' Perceived and Actual Probabilities of Pregnancy.

    ERIC Educational Resources Information Center

    Namerow, Pearila Brickner; And Others

    1987-01-01

    Explored adolescent females' (N=425) actual and perceived probabilities of pregnancy. Subjects estimated their likelihood of becoming pregnant the last time they had intercourse, and indicated the dates of last intercourse and last menstrual period. Found that the distributions of perceived probability of pregnancy were nearly identical for both…

  16. 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

    NASA Astrophysics Data System (ADS)

    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.

  17. The A=96 system in ββ decay

    SciTech Connect

    Alanssari, M.

    2015-10-28

    Properties of the single and double beta decays of {sup 96}Zr are discussed. It is argued that the single beta decay can provide important information to the neutrinoless variant of β β decay, as it provides a test of theories aimed at calculating the nuclear matrix elements (NME) for both decays. An experimental extraction of the NME for the single β decay requires a measurement of the decay Q-value and half-life. It is shown that the present Q-value of the {sup 96}Zr single β decay is insufficiently well known and requires a re-measurement, preferentially using high-precision ion traps. We also describe the geochemical method to determine the total half-life of {sup 96}Zr, from which to set a limit on the single β -decay half-life at a level of ≈15 × 10{sup 19}yr. Further, the geochemical analysis will allow setting a limit on a rather exotic quadruple β decay of {sup 96}Zr.

  18. What can we learn from neutrinoless double beta decay experiments?

    SciTech Connect

    Bahcall, John N.; Murayama, Hitoshi; Pena-Garay, Carlos

    2004-04-08

    We assess how well next generation neutrinoless double beta decay and normal neutrino beta decay experiments can answer four fundamental questions. 1) If neutrinoless double beta decay searches do not detect a signal, and if the spectrum is known to be inverted hierarchy, can we conclude that neutrinos are Dirac particles? 2) If neutrinoless double beta decay searches are negative and a next generation ordinary beta decay experiment detects the neutrino mass scale, can we conclude that neutrinos are Dirac particles? 3) If neutrinoless double beta decay is observed with a large neutrino mass element, what is the total mass in neutrinos? 4) If neutrinoless double beta decay is observed but next generation beta decay searches for a neutrino mass only set a mass upper limit, can we establish whether the mass hierarchy is normal or inverted? We base our answers on the expected performance of next generation neutrinoless double beta decay experiments and on simulations of the accuracy of calculations of nuclear matrix elements.

  19. HALF-LIVES OF LONG-LIVED ALPHA DECAY, BETA DECAY, ELECTRON CAPTURE DECAY, BETA BETA-DECAY, PROTON DECAY AND SPONTANEOUS FISSION DECAY NUCLIDES.

    SciTech Connect

    HOLDEN, H.E.

    2003-08-08

    In his review of radionuclides for dating purposes, Roth noted that there were a large number of nuclides, normally considered ''stable'' but which are radioactive with a very long half-life. Roth suggested that I review the data on the half-life values of these long-lived nuclides for the 2001 Atomic Weights Commission meeting in Brisbane. I provided a report, BNL-NCS-68377, to fulfill Roth's request. Peiser has now made a similar suggestion that I review these data for our next Commission meeting in Ottawa for their possible inclusion in our Tables. These half-life values for long-lived nuclides include those due to various decay modes, {alpha}-decay, {beta}-decay, electron capture decay, {beta}{beta}-decay, proton decay and spontaneous fission decay. This data review (post Brisbane) provides an update to the recommendation of the 2001 review.

  20. Reproducing Actual Morphology of Planetary Lava Flows

    NASA Astrophysics Data System (ADS)

    Miyamoto, H.; Sasaki, S.

    1996-03-01

    Assuming that lava flows behave as non-isothermal laminar Bingham fluids, we developed a numerical code of lava flows. We take the self gravity effects and cooling mechanisms into account. The calculation method is a kind of cellular automata using a reduced random space method, which can eliminate the mesh shape dependence. We can calculate large scale lava flows precisely without numerical instability and reproduce morphology of actual lava flows.

  1. The Actual Apollo 13 Prime Crew

    NASA Technical Reports Server (NTRS)

    1970-01-01

    The actual Apollo 13 lunar landing mission prime crew from left to right are: Commander, James A. Lovell Jr., Command Module pilot, John L. Swigert Jr.and Lunar Module pilot, Fred W. Haise Jr. The original Command Module pilot for this mission was Thomas 'Ken' Mattingly Jr. but due to exposure to German measles he was replaced by his backup, Command Module pilot, John L. 'Jack' Swigert Jr.

  2. NUCLEAR DATA RESOURCES FOR ADVANCED ANALYSIS AND SIMULATION.

    SciTech Connect

    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.

  3. Suppressed Charmed B Decay

    SciTech Connect

    Snoek, Hella Leonie

    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

  4. Decay of superdeformed bands

    SciTech Connect

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

    1995-12-31

    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 {sup 194}Hg. 42 refs., 5 figs.

  5. Measuring pion beta decay with high-energy pion beams

    SciTech Connect

    McFarlane, W.K. |; Hoffman, C.M.

    1993-02-01

    Improved measurements of the pion beta decay rate are possible with an intense high-energy pion beam. The rate for the decay {pi}{sup +} {yields} {pi}{sup 0}e{sup +}v{epsilon} is predicted by the Standard Model (SM) to be R({pi}{sup +} {yields} {pi}{sup 0}e{sup +}v{epsilon}) = 0.3999{plus_minus}0.0005 s{sup {minus}1}. The best experimental number, obtained using in-flight decays, is R({pi}{sup +} {yields} {pi}{sup 0}e{sup +}v{epsilon}) = 0.394 {plus_minus} 0.015 s{sup {minus}1}. A precise measurement would test the SM by testing the unitarity of the Cabibbo-Kobayashi-Maskawa matrix for which one analysis of the nuclear beta decay data has shown a 0.4% discrepancy. Several nuclear correction factors, needed for nuclear decay, are not present for pion beta decay, so that an experiment at the 0.2% level would be a significant one. Detailed study of possible designs will be needed, as well as extensive testing of components. The reduction of systematic errors to the 0.1% level can only be done over a period of years with a highly stable apparatus and beam. At a minimum, three years of occupancy of a beam line, with 800 hours per year, would be required.

  6. Measuring pion beta decay with high-energy pion beams

    SciTech Connect

    McFarlane, W.K. Temple Univ., Philadelphia, PA ); Hoffman, C.M. )

    1993-01-01

    Improved measurements of the pion beta decay rate are possible with an intense high-energy pion beam. The rate for the decay [pi][sup +] [yields] [pi][sup 0]e[sup +]v[epsilon] is predicted by the Standard Model (SM) to be R([pi][sup +] [yields] [pi][sup 0]e[sup +]v[epsilon]) = 0.3999[plus minus]0.0005 s[sup [minus]1]. The best experimental number, obtained using in-flight decays, is R([pi][sup +] [yields] [pi][sup 0]e[sup +]v[epsilon]) = 0.394 [plus minus] 0.015 s[sup [minus]1]. A precise measurement would test the SM by testing the unitarity of the Cabibbo-Kobayashi-Maskawa matrix for which one analysis of the nuclear beta decay data has shown a 0.4% discrepancy. Several nuclear correction factors, needed for nuclear decay, are not present for pion beta decay, so that an experiment at the 0.2% level would be a significant one. Detailed study of possible designs will be needed, as well as extensive testing of components. The reduction of systematic errors to the 0.1% level can only be done over a period of years with a highly stable apparatus and beam. At a minimum, three years of occupancy of a beam line, with 800 hours per year, would be required.

  7. AN HISTORICAL OVERVIEW OF THE IMPORTANCE OF THE WEAK DECAY OF HYPERNUCLEI

    SciTech Connect

    B. F. GIBSON

    2001-01-09

    Weak decay of hypernuclei, first cousin to the {beta}-decay of conventional, nonstrange nuclei, was initially observed in the 1950s. Pionic decay rates have proven a challenge--to reconcile nuclear decay rates with that of free {lambda} decay. Pauli blocking of the decay nucleon plays an important role. Nonmesonic decay provides our only practical means of exploring the four-fermion, strangeness-changing N{Lambda} {yields} NN weak interaction. The N{Lambda}{rho} vertex can be investigated in no other way. The large momentum transfer in the nonmesonic decay process suggests a means to probe short distance aspects of the interaction, possibly revealing baryon substructure effects. Whether the {Delta}I = 1/2 rule, which governs free {Lambda} decay, also applies to the nonmesonic decay process remains an open question. The free {Lambda} does not decay by emission of a {pi}{sup +}; the {pi}{sup +} decay of {sup 4}He is a puzzle. Finally, the weak decay of strangeness -2 hypernuclei is an important topic, because the pionic decay process is central to current efforts to seek and identify {Lambda}{Lambda} hypernuclei.

  8. Weak decay of hypernuclei

    SciTech Connect

    Grace, R.

    1983-01-01

    The Moby Dick spectrometer (at BNL) in coincidence with a range spectrometer and a TOF neutron detector will be used to study the weak decay modes of /sup 12/C. The Moby Dick spectrometer will be used to reconstruct and tag events in which specific hypernuclear states are formed in the reaction K/sup -/ + /sup 12/C ..-->.. ..pi../sup -/ + /sup 12/C. Subsequent emission of decay products (pions, protons and neutrons) in coincidence with the fast forward pion will be detected in a time and range spectrometer, and a neutron detector.

  9. Search for the decay

    NASA Astrophysics Data System (ADS)

    Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Aquines Gutierrez, O.; Archilli, F.; d'Argent, P.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Bel, L. J.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bertolin, A.; Bettler, M.-O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Bird, T.; Birnkraut, A.; Bizzeti, A.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borsato, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Braun, S.; Brett, D.; Britsch, M.; Britton, T.; Brodzicka, J.; Brook, N. H.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Campana, P.; Campora Perez, D.; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carniti, P.; Carson, L.; Carvalho Akiba, K.; Casanova Mohr, R.; Casse, G.; Cassina, L.; Castillo Garcia, L.; Cattaneo, M.; Cauet, Ch.; Cavallero, G.; Cenci, R.; Charles, M.; Charpentier, Ph.; Chefdeville, M.; Chen, S.; Cheung, S.-F.; Chiapolini, N.; Chrzaszcz, M.; Cid Vidal, X.; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collazuol, G.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Corvo, M.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A.; Cruz Torres, M.; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Dalseno, J.; David, P. N. Y.; Davis, A.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Silva, W.; De Simone, P.; Dean, C.-T.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Déléage, N.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Di Ruscio, F.; Dijkstra, H.; Donleavy, S.; Dordei, F.; Dorigo, M.; Dosil Suárez, A.; Dossett, D.; Dovbnya, A.; Dreimanis, K.; Dujany, G.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T.; Falabella, A.; Färber, C.; Farinelli, C.; Farley, N.; Farry, S.; Fay, R.; Ferguson, D.; Fernandez Albor, V.; Ferrari, F.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fol, P.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; García Pardiñas, J.; Garofoli, J.; Garra Tico, J.; Garrido, L.; Gascon, D.; Gaspar, C.; Gastaldi, U.; Gauld, R.; Gavardi, L.; Gazzoni, G.; Geraci, A.; Gerick, D.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianelle, A.; Gianì, S.; Gibson, V.; Giubega, L.; Gligorov, V. V.; Göbel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gotti, C.; Grabalosa Gándara, M.; Graciani Diaz, R.; Granado Cardoso, L. A.; Graugés, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griffith, P.; Grillo, L.; Grünberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Hampson, T.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; Hernando Morata, J. A.; van Herwijnen, E.; Heß, M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Humair, T.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jawahery, A.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Karodia, S.; Kelsey, M.; Kenyon, I. R.; Kenzie, M.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.; Klimaszewski, K.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Korolev, M.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kurek, K.; Kvaratskheliya, T.; La Thi, V. N.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lambert, R. W.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J.-P.; Lefèvre, R.; Leflat, A.; Lefrançois, J.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Likhomanenko, T.; Liles, M.; Lindner, R.; Linn, C.; Lionetto, F.; Liu, B.; Lohn, S.; Longstaff, I.; Lopes, J. H.; Lucchesi, D.; Lucio Martinez, M.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Machefert, F.; Maciuc, F.; Maev, O.; Malde, S.; Malinin, A.; Manca, G.; Mancinelli, G.; Manning, P.; Mapelli, A.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marino, P.; Märki, R.; Marks, J.; Martellotti, G.; Martinelli, M.; Martinez Santos, D.; Martinez Vidal, F.; Martins Tostes, D.; Massafferri, A.; Matev, R.; Mathad, A.; Mathe, Z.; Matteuzzi, C.; Matthieu, K.; Mauri, A.; Maurin, B.; Mazurov, A.; McCann, M.; McCarthy, J.; McNab, A.; McNulty, R.; Meadows, B.; Meier, F.; Meissner, M.; Merk, M.; Milanes, D. A.; Minard, M.-N.; Mitzel, D. S.; Molina Rodriguez, J.; Monteil, S.; Morandin, M.; Morawski, P.; Mordà, A.; Morello, M. J.; Moron, J.; Morris, A. B.; Mountain, R.; Muheim, F.; Müller, J.; Müller, K.; Müller, V.; Mussini, M.; Muster, B.; Naik, P.; Nakada, T.; Nandakumar, R.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen, T. D.; Nguyen-Mau, C.; Niess, V.; Niet, R.; Nikitin, N.; Nikodem, T.; Ninci, D.; Novoselov, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Onderwater, C. J. G.; Osorio Rodrigues, B.; Otalora Goicochea, J. M.; Otto, A.; Owen, P.; Oyanguren, A.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Parkes, C.; Passaleva, G.; Patel, G. D.; Patel, M.; Patrignani, C.; Pearce, A.; Pellegrino, A.; Penso, G.; Pepe Altarelli, M.; Perazzini, S.; Perret, P.; Pescatore, L.; Petridis, K.; Petrolini, A.; Petruzzo, M.; Picatoste Olloqui, E.; Pietrzyk, B.; Pilař, T.; Pinci, D.; Pistone, A.; Playfer, S.; Plo Casasus, M.; Poikela, T.; Polci, F.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Popov, A.; Popov, D.; Popovici, B.; Potterat, C.; Price, E.; Price, J. D.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Puig Navarro, A.; Punzi, G.; Qian, W.; Quagliani, R.; Rachwal, B.; Rademacker, J. H.; Rakotomiaramanana, B.; Rama, M.; Rangel, M. S.; Raniuk, I.; Rauschmayr, N.; Raven, G.; Redi, F.; Reichert, S.; Reid, M. M.; dos Reis, A. C.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Robbe, P.; Rodrigues, A. B.; Rodrigues, E.; Rodriguez Lopez, J. A.; Rodriguez Perez, P.; Roiser, S.; Romanovsky, V.; Romero Vidal, A.; Rotondo, M.; Rouvinet, J.; Ruf, T.; Ruiz, H.; Ruiz Valls, P.; Saborido Silva, J. J.; Sagidova, N.; Sail, P.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santovetti, E.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmelzer, T.; Schmidt, B.; Schneider, O.; Schopper, A.; Schune, M.-H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sepp, I.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Shires, A.; Silva Coutinho, R.; Simi, G.; Sirendi, M.; Skidmore, N.; Skillicorn, I.; Skwarnicki, T.; Smith, E.; Smith, E.; Smith, J.; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Soomro, F.; Souza, D.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Steinkamp, O.; Stenyakin, O.; Sterpka, F.; Stevenson, S.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Stroili, R.; Sun, L.; Sutcliffe, W.; Swientek, K.; Swientek, S.; Syropoulos, V.; Szczekowski, M.; Szczypka, P.; Szumlak, T.; T'Jampens, S.; Tekampe, T.; Teklishyn, M.; Tellarini, G.; Teubert, F.; Thomas, C.; Thomas, E.; van Tilburg, J.; Tisserand, V.; Tobin, M.; Todd, J.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Trabelsi, K.; Tran, M. T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagnoni, V.; Valenti, G.; Vallier, A.; Vazquez Gomez, R.; Vazquez Regueiro, P.; Vázquez Sierra, C.; Vecchi, S.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Vesterinen, M.; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Vilasis-Cardona, X.; Vollhardt, A.; Volyanskyy, D.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voß, C.; de Vries, J. A.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wandernoth, S.; Wang, J.; Ward, D. R.; Watson, N. K.; Websdale, D.; Weiden, A.; Whitehead, M.; Wiedner, D.; Wilkinson, G.; Wilkinson, M.; Williams, M.; Williams, M. P.; Williams, M.; Wilson, F. F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wright, S.; Wyllie, K.; Xie, Y.; Xu, Z.; Yang, Z.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zavertyaev, M.; Zhang, L.; Zhang, Y.; Zhelezov, A.; Zhokhov, A.; Zhong, L.

    2015-08-01

    A search for decays is performed using 3 .0 fb1- of pp collision data recorded by the LHCb experiment during 2011 and 2012. The f 0(980) meson is reconstructed through its decay to the π + π - final state in the mass window 900 MeV /c 2 < m( π + π -) < 1080 MeV /c 2. No significant signal is observed. The first upper limits on the branching fraction of are set at 90 % (95 %) confidence level. [Figure not available: see fulltext.

  10. Complete correlation studies of two-proton decays: 6Be and 45Fe

    SciTech Connect

    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.

    2009-06-01

    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.

  11. Recent advances in β-decay spectroscopy at CARIBU

    NASA Astrophysics Data System (ADS)

    Mitchell, A. J.; Copp, P.; Savard, G.; Lister, C. J.; Lane, G. J.; Carpenter, M. P.; Clark, J. A.; Zhu, S.; Ayangeakaa, A. D.; Bottoni, S.; Brown, T. B.; Chowdhury, P.; Chillery, T. W.; David, H. M.; Hartley, D. J.; Heckmaier, E.; Janssens, R. V. F.; Kolos, K.; Kondev, F. G.; Lauritsen, T.; McCutchan, E. A.; Norman, E. B.; Padgett, S.; Scielzo, N. D.; Seweryniak, D.; Smith, M. L.; Wilson, G. L.

    2016-09-01

    β-decay spectroscopy of nuclei far from stability can provide powerful insight into a broad variety of topics in nuclear science, ranging from exotic nuclear structure phenomena, stellar nucleosynthesis processes, and applied topics such as quantifying "decay heat" discrepancies for advanced nuclear fuel cycles. Neutronrich nuclei approaching the drip-line are difficult to access experimentally, leaving many key examples largely under studied. The CARIBU radioactive beam facility at Argonne National Laboratory exploits spontaneous fission of 252Cf in production of such beams. The X-Array and SATURN decay station have been commissioned to perform detailed decay spectroscopy of low-energy CARIBU beams. An extended science campaign was started during 2015; with projects investigating nuclear shape changes, collective octupole vibrations, β-delayed neutron emission, and decay-scheme properties which could explain the reactor antineutrino puzzle. In this article we review the current status of the setup, update on the first results and recent hardware upgrades, and look forward to future possibilities.

  12. Fundamentals in Nuclear Physics

    NASA Astrophysics Data System (ADS)

    Basdevant, Jean-Louis, Rich, James, Spiro, Michael

    This course on nuclear physics leads the reader to the exploration of the field from nuclei to astrophysical issues. Much nuclear phenomenology can be understood from simple arguments such as those based on the Pauli principle and the Coulomb barrier. This book is concerned with extrapolating from such arguments and illustrating nuclear systematics with experimental data. Starting with the basic concepts in nuclear physics, nuclear models, and reactions, the book covers nuclear decays and the fundamental electro-weak interactions, radioactivity, and nuclear energy. After the discussions of fission and fusion leading into nuclear astrophysics, there is a presentation of the latest ideas about cosmology. As a primer this course will lay the foundations for more specialized subjects. This book emerged from a series of topical courses the authors delivered at the Ecole Polytechnique and will be useful for graduate students and for scientists in a variety of fields.

  13. Actual and Simulated Weightlessness Inhibit Osteogenesis in Long Bone Metaphysis by Different Mechanisms

    NASA Technical Reports Server (NTRS)

    Roberts, W. E.

    1985-01-01

    Weightlessness and simulated weightlessness inhibit the rate of periosteal bone formation in long bones. Formation of preosteoblasts is suppressed in periodontal ligament (PDL) of maxillary molars, which suggests a generalized block in osteoblast histogenesis. Growth in length of long bones is decreased by simulated weightlessness, but there are no reliable data on the influence of actual weightlessness on metaphyseal growth. The nuclear size assay for assessing relative numbers of osteoblast precursor cells was utilized in the primary spongiosa of growing long bones subjected to actual and simulated weightlessness. It is found that: (1) Actual weightlessness decreases total number of osteogenic cells and inhibits differentiation of osteoblast precursor cells, (2) Simulated weightlessness suppresses only osteoblast differentation; and (3) The nuclear morphometric assay is an effective means of assessing osteogenic activity in the growing metaphysis or long bones.

  14. On the neutrinoless double β{sup +}/EC decays

    SciTech Connect

    Suhonen, Jouni

    2013-12-30

    The neutrinoless double positron-emission/electron-capture (0νβ{sup +}/EC) decays are studied for the magnitudes of the involved nuclear matrix elements (NMEs). Decays to the ground state, 0{sub gs}{sup +}, and excited 0{sup +} states are discussed. The participant many-body wave functions are evaluated in the framework of the quasiparticle random-phase approximation (QRPA). Effective, G-matrix-derived nuclear forces are used in realistic single-particle model spaces. The channels β{sup +}β{sup +}, β{sup +}EC, and the resonant neutrinoless double electron capture (R0νECEC) are discussed.

  15. Air resistance measurements on actual airplane parts

    NASA Technical Reports Server (NTRS)

    Weiselsberger, C

    1923-01-01

    For the calculation of the parasite resistance of an airplane, a knowledge of the resistance of the individual structural and accessory parts is necessary. The most reliable basis for this is given by tests with actual airplane parts at airspeeds which occur in practice. The data given here relate to the landing gear of a Siemanms-Schuckert DI airplane; the landing gear of a 'Luftfahrzeug-Gesellschaft' airplane (type Roland Dlla); landing gear of a 'Flugzeugbau Friedrichshafen' G airplane; a machine gun, and the exhaust manifold of a 269 HP engine.

  16. Explosive Percolation Transition is Actually Continuous

    NASA Astrophysics Data System (ADS)

    da Costa, R. A.; Dorogovtsev, S. N.; Goltsev, A. V.; Mendes, J. F. F.

    2010-12-01

    Recently a discontinuous percolation transition was reported in a new “explosive percolation” problem for irreversible systems [D. Achlioptas, R. M. D’Souza, and J. Spencer, Science 323, 1453 (2009)SCIEAS0036-807510.1126/science.1167782] in striking contrast to ordinary percolation. We consider a representative model which shows that the explosive percolation transition is actually a continuous, second order phase transition though with a uniquely small critical exponent of the percolation cluster size. We describe the unusual scaling properties of this transition and find its critical exponents and dimensions.

  17. BABAR B Decay Results

    SciTech Connect

    MacFarlane, David B

    2002-03-14

    Data from the first run of the BABAR detector at the PEP II accelerator are presented. Measurements of many rare B decay modes are now possible using the large data sets currently being collected by BABAR. An overview of analysis techniques and results on data collected in 2000 are described.

  18. Cosmology with decaying particles

    SciTech Connect

    Turner, M.S.

    1984-09-01

    We consider a cosmological model in which an unstable massive relic particle species (denoted by X) has an initial mass density relative to baryons ..beta../sup -1/ identically equal rho/sub X//rho/sub B/ >> 1, and then decays recently (redshift z less than or equal to 1000) into particles which are still relativistic today (denoted by R). We write down and solve the coupled equations for the cosmic scale factor a(t), the energy density in the various components (rho/sub X/, rho/sub R/, rho/sub B/), and the growth of linear density perturbations (delta rho/rho). The solutions form a one parameter (..beta..) family of solutions; physically ..beta../sup -1/ approx. = (..cap omega../sub R//..cap omega../sub NR/) x (1 + z/sub D/) = (ratio today of energy density of relativistic to nonrelativistic particles) x (1 + redshift of (decay)). We discuss the observational implications of such a cosmological model and compare our results to earlier results computed in the simultaneous decay approximation. In an appendix we briefly consider the case where one of the decay products of the X is massive and becomes nonrelativistic by the present epoch. 21 references.

  19. Semileptonic B Meson Decays

    SciTech Connect

    Luth, Vera G.; /SLAC

    2012-01-03

    Semileptonic decays of B mesons play a critical role in the determination of the magnitude of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements V{sub cb} and V{sub ub}. These two quantities are fundamental parameters of the Standard Model and have to be determined experimentally. Over the past decade, the vast samples of B mesons recorded at the B factories at LEP at Cornell University, KEK at Tsukuba, and SLAC at Stanford University have allowed for detailed studies of semileptonic B decays. These decays proceed via first-order weak interactions; thus, they are expected to be free of non-Standard Model contributions and therefore are well suited for the extraction of the quark-mixing parameters. Differential decay rates are combined with theoretical calculations of hadronization effects, leading to a substantially improved knowledge of |V{sub cb}| and |V{sub ub}|. The results are used to constrain the parameters of the CKM matrix and to test the Standard Model predictions for CP-violating effects.

  20. Decay Time of Cathodoluminescence

    ERIC Educational Resources Information Center

    Kraftmakher, Yaakov

    2009-01-01

    Simple measurements of the decay time of cathodoluminescence are described. Cathodoluminescence is used in many devices, including computer monitors, oscilloscopes, radar displays and television tubes. The experimental setup is simple and easy to build. Two oscilloscopes, a function generator, and a fast photodiode are needed for the experiments.…

  1. Tooth decay - early childhood

    MedlinePlus

    Bottle mouth; Bottle carries; Baby bottle tooth decay; Early childhood caries (ECC) ... Your child needs strong, healthy baby teeth to chew food and to talk. Baby teeth also make space in children's jaws for their adult teeth to grow in straight. ...

  2. Introduction to nuclear physics.

    PubMed

    Patton, J A

    1998-01-01

    Photons for counting or imaging applications in nuclear medicine result from several processes. Gamma rays are produced from excited state transitions after beta decay and electron capture. Annihilation photons result from positron decay. The de-excitation of the atom after electron capture results in the production of characteristic x rays or Auger electrons. Metastable state transitions result in gamma ray emission or internal conversion electrons. All radiopharmaceuticals used in diagnostic nuclear medicine applications are tagged with radionuclides that emit photons as a result of one of these processes.

  3. Radioactive Doses - Predicted and Actual - and Likely Health Effects.

    PubMed

    Nagataki, S; Takamura, N

    2016-04-01

    Five years have passed since the nuclear accident at Fukushima Daiichi Nuclear Power Stations on 11 March 2011. Here we refer to reports from international organisations as sources of predicted values obtained from environmental monitoring and dose estimation models, and reports from various institutes in Japan are used as sources of individual actual values. The World Health Organization, based on information available up to 11 September 2011 (and published in 2012), reported that characteristic effective doses in the first year after the accident, to all age groups, were estimated to be in the 10-50 mSv dose band in example locations in evacuation areas. Estimated characteristic thyroid doses to infants in Namie Town were within the 100-200 mSv dose band. A report from the United Nations Scientific Committee on the Effects of Atomic Radiation published in 2014 shows that the effective dose received by adults in evacuation areas during the first year after the accident was 1.1-13 mSv. The absorbed dose to the thyroid in evacuated settlements was 7.2-35 mSv in adults and 15-83 mSv in 1-year-old infants. Individual external radiation exposure in the initial 4 months after the accident, estimated by superimposing individual behaviour data on to a daily dose rate map, was less than 3 mSv in 93.9% of residents (maximum 15 mSv) in evacuation areas. Actual individual thyroid equivalent doses were less than 15 mSv in 98.8% of children (maximum 25 mSv) in evacuation areas. When uncertainty exists in dose estimation models, it may be sensible to err on the side of caution, and final estimated doses are often much greater than actual radiation doses. However, overestimation of the dose at the time of an accident has a great influence on the psychology of residents. More than 100 000 residents have not returned to the evacuation areas 5 years after the Fukushima accident because of the social and mental effects during the initial period of the disaster. Estimates of

  4. Radioactive Doses - Predicted and Actual - and Likely Health Effects.

    PubMed

    Nagataki, S; Takamura, N

    2016-04-01

    Five years have passed since the nuclear accident at Fukushima Daiichi Nuclear Power Stations on 11 March 2011. Here we refer to reports from international organisations as sources of predicted values obtained from environmental monitoring and dose estimation models, and reports from various institutes in Japan are used as sources of individual actual values. The World Health Organization, based on information available up to 11 September 2011 (and published in 2012), reported that characteristic effective doses in the first year after the accident, to all age groups, were estimated to be in the 10-50 mSv dose band in example locations in evacuation areas. Estimated characteristic thyroid doses to infants in Namie Town were within the 100-200 mSv dose band. A report from the United Nations Scientific Committee on the Effects of Atomic Radiation published in 2014 shows that the effective dose received by adults in evacuation areas during the first year after the accident was 1.1-13 mSv. The absorbed dose to the thyroid in evacuated settlements was 7.2-35 mSv in adults and 15-83 mSv in 1-year-old infants. Individual external radiation exposure in the initial 4 months after the accident, estimated by superimposing individual behaviour data on to a daily dose rate map, was less than 3 mSv in 93.9% of residents (maximum 15 mSv) in evacuation areas. Actual individual thyroid equivalent doses were less than 15 mSv in 98.8% of children (maximum 25 mSv) in evacuation areas. When uncertainty exists in dose estimation models, it may be sensible to err on the side of caution, and final estimated doses are often much greater than actual radiation doses. However, overestimation of the dose at the time of an accident has a great influence on the psychology of residents. More than 100 000 residents have not returned to the evacuation areas 5 years after the Fukushima accident because of the social and mental effects during the initial period of the disaster. Estimates of

  5. Constraining decaying dark matter with neutron stars

    NASA Astrophysics Data System (ADS)

    Pérez-García, M. Ángeles; Silk, Joseph

    2015-05-01

    The amount of decaying dark matter, accumulated in the central regions in neutron stars together with the energy deposition rate from decays, may set a limit on the neutron star survival rate against transitions to more compact objects provided nuclear matter is not the ultimate stable state of matter and that dark matter indeed is unstable. More generally, this limit sets constraints on the dark matter particle decay time, τχ. We find that in the range of uncertainties intrinsic to such a scenario, masses (mχ /TeV) ≳ 9 ×10-4 or (mχ /TeV) ≳ 5 ×10-2 and lifetimes τχ ≲1055 s and τχ ≲1053 s can be excluded in the bosonic or fermionic decay cases, respectively, in an optimistic estimate, while more conservatively, it decreases τχ by a factor ≳1020. We discuss the validity under which these results may improve with other current constraints.

  6. Fine structure in the cluster decays of the translead nuclei

    SciTech Connect

    Dumitrescu, O. |; Cioaca, C.

    1995-06-01

    Within the one level {ital R}-matrix approach several hindrance factors for the radioactive decays in which are emitted {sup 4}He, {sup 14}C, and {sup 20}O atomic nuclei are calculated. The interior wave functions are supposed to be given by the recently proposed enlarged superfluid model, an extension of the JINR-Dubna`s quasiparticle phonon nuclear model. The spectroscopic factors are expanded in terms of products of cluster overlaps and intrinsic overlap integrals. The cluster overlaps are equivalents of the generalized coefficients of fractional parentage, while for the intrinsic overlap integrals we construct a model, which is an extension of the usual models for simple particle decay such as deuteron, triton, and {alpha} decay. The exterior wave functions are calculated from a cluster-nucleus double-folding model potential obtained with the {ital M}3{ital Y} interaction. As examples of the cluster decay fine structure we analyzed the particular cases of {alpha} decay of {sup 255}Fm, {sup 14}C decay of {sup 223}Ra and {sup 20}O decay of {sup 229}Th and {sup 255}Fm. A relatively good agreement with the experimental data is obtained especially in the case of the {alpha}-decay fine structure.

  7. Anatomy of decays

    NASA Astrophysics Data System (ADS)

    Bel, Lennaert; De Bruyn, Kristof; Fleischer, Robert; Mulder, Mick; Tuning, Niels

    2015-07-01

    The decays B {/d 0} → D {/d -} D {/d +} and B {/s 0} → D {/s -} D {/s +} probe the CP-violating mixing phases ϕ d and ϕ s , respectively. The theoretical uncertainty of the corresponding determinations is limited by contributions from penguin topologies, which can be included with the help of the U-spin symmetry of the strong interaction. We analyse the currently available data for B {/d, s 0} → D {/d, s -} D {/d, s +} decays and those with similar dynamics to constrain the involved non-perturbative parameters. Using further information from semileptonic B {/d 0} → D {/d -} ℓ + ν ℓ decays, we perform a test of the factorisation approximation and take non-factorisable SU(3)-breaking corrections into account. The branching ratios of the B {/d 0} → D {/d -} D {/d +}, B {/s 0} → D {/s -} D {/d +} and B {/s 0} → D {/s -} D {/s +}, B {/d 0} → D {/d -} D {/s +} decays show an interesting pattern which can be accommodated through significantly enhanced exchange and penguin annihilation topologies. This feature is also supported by data for the B {/s 0} → D {/d -} D {/d +} channel. Moreover, there are indications of potentially enhanced penguin contributions in the B {/d 0} → D {/d -} D {/d +} and B {/s 0} → D {/s -} D {/s +} decays, which would make it mandatory to control these effects in the future measurements of ϕ d and ϕ s . We discuss scenarios for high-precision measurements in the era of Belle II and the LHCb upgrade.

  8. Modeling Radionuclide Decay Chain Migration Using HYDROGEOCHEM

    NASA Astrophysics Data System (ADS)

    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.

  9. B Decays Involving Light Mesons

    NASA Astrophysics Data System (ADS)

    Eschrich, Ivo Gough

    Recent BABAR results for decays of B-mesons to combinations of non-charm mesons are presented. This includes B decays to two vector mesons, B → η‧(π, K, ρ) modes, and a comprehensive Dalitz Plot analysis of B → KKK decays.

  10. B Decays Involving Light Mesons

    SciTech Connect

    Eschrich, Ivo Gough; /UC, Irvine

    2007-01-09

    Recent BABAR results for decays of B-mesons to combinations of non-charm mesons are presented. This includes B decays to two vector mesons, B {yields} {eta}{prime}({pi}, K, {rho}) modes, and a comprehensive Dalitz Plot analysis of B {yields} KKK decays.

  11. The actual status of Astronomy in Moldova

    NASA Astrophysics Data System (ADS)

    Gaina, A.

    The astronomical research in the Republic of Moldova after Nicolae Donitch (Donici)(1874-1956(?)) were renewed in 1957, when a satellites observations station was open in Chisinau. Fotometric observations and rotations of first Soviet artificial satellites were investigated under a program SPIN put in action by the Academy of Sciences of former Socialist Countries. The works were conducted by Assoc. prof. Dr. V. Grigorevskij, which conducted also research in variable stars. Later, at the beginning of 60-th, an astronomical Observatory at the Chisinau State University named after Lenin (actually: the State University of Moldova), placed in Lozovo-Ciuciuleni villages was open, which were coordinated by Odessa State University (Prof. V.P. Tsesevich) and the Astrosovet of the USSR. Two main groups worked in this area: first conducted by V. Grigorevskij (till 1971) and second conducted by L.I. Shakun (till 1988), both graduated from Odessa State University. Besides this research areas another astronomical observations were made: Comets observations, astroclimate and atmospheric optics in collaboration with the Institute of the Atmospheric optics of the Siberian branch of the USSR (V. Chernobai, I. Nacu, C. Usov and A.F. Poiata). Comets observations were also made since 1988 by D. I. Gorodetskij which came to Chisinau from Alma-Ata and collaborated with Ukrainean astronomers conducted by K.I. Churyumov. Another part of space research was made at the State University of Tiraspol since the beggining of 70-th by a group of teaching staff of the Tiraspol State Pedagogical University: M.D. Polanuer, V.S. Sholokhov. No a collaboration between Moldovan astronomers and Transdniestrian ones actually exist due to War in Transdniestria in 1992. An important area of research concerned the Radiophysics of the Ionosphere, which was conducted in Beltsy at the Beltsy State Pedagogical Institute by a group of teaching staff of the University since the beginning of 70-th: N. D. Filip, E

  12. MODIS Solar Diffuser: Modelled and Actual Performance

    NASA Technical Reports Server (NTRS)

    Waluschka, Eugene; Xiong, Xiao-Xiong; Esposito, Joe; Wang, Xin-Dong; Krebs, Carolyn (Technical Monitor)

    2001-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument's solar diffuser is used in its radiometric calibration for the reflective solar bands (VIS, NTR, and SWIR) ranging from 0.41 to 2.1 micron. The sun illuminates the solar diffuser either directly or through a attenuation screen. The attenuation screen consists of a regular array of pin holes. The attenuated illumination pattern on the solar diffuser is not uniform, but consists of a multitude of pin-hole images of the sun. This non-uniform illumination produces small, but noticeable radiometric effects. A description of the computer model used to simulate the effects of the attenuation screen is given and the predictions of the model are compared with actual, on-orbit, calibration measurements.

  13. 7 CFR 1437.101 - Actual production history.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Actual production history. 1437.101 Section 1437.101... Determining Yield Coverage Using Actual Production History § 1437.101 Actual production history. Actual production history (APH) is the unit's record of crop yield by crop year for the APH base period. The...

  14. 7 CFR 1437.101 - Actual production history.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Actual production history. 1437.101 Section 1437.101... Determining Yield Coverage Using Actual Production History § 1437.101 Actual production history. Actual production history (APH) is the unit's record of crop yield by crop year for the APH base period. The...

  15. 7 CFR 1437.101 - Actual production history.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Actual production history. 1437.101 Section 1437.101... Determining Yield Coverage Using Actual Production History § 1437.101 Actual production history. Actual production history (APH) is the unit's record of crop yield by crop year for the APH base period. The...

  16. 7 CFR 1437.101 - Actual production history.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Actual production history. 1437.101 Section 1437.101... Determining Yield Coverage Using Actual Production History § 1437.101 Actual production history. Actual production history (APH) is the unit's record of crop yield by crop year for the APH base period. The...

  17. 7 CFR 1437.101 - Actual production history.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Actual production history. 1437.101 Section 1437.101... Determining Yield Coverage Using Actual Production History § 1437.101 Actual production history. Actual production history (APH) is the unit's record of crop yield by crop year for the APH base period. The...

  18. Decay Dynamics of Tumors

    PubMed Central

    2016-01-01

    The fractional cell kill is a mathematical expression describing the rate at which a certain population of cells is reduced to a fraction of itself. We investigate the mathematical function that governs the rate at which a solid tumor is lysed by a cell population of cytotoxic lymphocytes. We do it in the context of enzyme kinetics, using geometrical and analytical arguments. We derive the equations governing the decay of a tumor in the limit in which it is plainly surrounded by immune cells. A cellular automaton is used to test such decay, confirming its validity. Finally, we introduce a modification in the fractional cell kill so that the expected dynamics is attained in the mentioned limit. We also discuss the potential of this new function for non-solid and solid tumors which are infiltrated with lymphocytes. PMID:27310010

  19. Kinetics analysis and quantitative calculations for the successive radioactive decay process

    NASA Astrophysics Data System (ADS)

    Zhou, Zhiping; Yan, Deyue; Zhao, Yuliang; Chai, Zhifang

    2015-01-01

    The general radioactive decay kinetics equations with branching were developed and the analytical solutions were derived by Laplace transform method. The time dependence of all the nuclide concentrations can be easily obtained by applying the equations to any known radioactive decay series. Taking the example of thorium radioactive decay series, the concentration evolution over time of various nuclide members in the family has been given by the quantitative numerical calculations with a computer. The method can be applied to the quantitative prediction and analysis for the daughter nuclides in the successive decay with branching of the complicated radioactive processes, such as the natural radioactive decay series, nuclear reactor, nuclear waste disposal, nuclear spallation, synthesis and identification of superheavy nuclides, radioactive ion beam physics and chemistry, etc.

  20. Decay Heat Measurements Using Total Absorption Gamma-ray Spectroscopy

    NASA Astrophysics Data System (ADS)

    Rice, S.; Valencia, E.; Algora, A.; Taín, J. L.; Regan, P. H.; Podolyák, Z.; Agramunt, J.; Gelletly, W.; Nichols, A. L.

    2012-09-01

    A knowledge of the decay heat emitted by thermal neutron-irradiated nuclear fuel is an important factor in ensuring safe reactor design and operation, spent fuel removal from the core, and subsequent storage prior to and after reprocessing, and waste disposal. Decay heat can be readily calculated from the nuclear decay properties of the fission products, actinides and their decay products as generated within the irradiated fuel. Much of the information comes from experiments performed with HPGe detectors, which often underestimate the beta feeding to states at high excitation energies. This inability to detect high-energy gamma emissions effectively results in the derivation of decay schemes that suffer from the pandemonium effect, although such a serious problem can be avoided through application of total absorption γ-ray spectroscopy (TAS). The beta decay of key radionuclei produced as a consequence of the neutron-induced fission of 235U and 239Pu are being re-assessed by means of this spectroscopic technique. A brief synopsis is given of the Valencia-Surrey (BaF2) TAS detector, and their method of operation, calibration and spectral analysis.

  1. Validation and Testing of ENDF/B-VII Decay Data

    SciTech Connect

    Gauld, I.C. Pigni, M.T.; Ilas, G.

    2014-06-15

    The nuclear decay library developed for the ORIGEN code was upgraded from ENDF/B-VI.8 to -VII.0 and released in the SCALE nuclear modeling and simulation code system in 2011. Experience with the ENDF/B-VII.0 library identified serious errors and performance issues in the evaluated decay sublibrary. Initially, errors were identified in the decay scheme for the {sup 238}U series, leading to large discrepancies in the gamma emission rate for uranium. Further testing of the fission product decay data revealed significant performance issues with ENDF/B-VII.0 relative to the previous release of ENDF/B-VI. To address the performance issues, the decay data library in SCALE was upgraded to ENDF/B-VII.1 and released as an update for users in 2013. This paper describes the practical impact of the ENDF/B-VII.0 decay data performance issues on common code applications, and the validation and testing performed on the updated ORIGEN libraries developed from the ENDF/B-VII.1 sublibrary.

  2. Validation and Testing of ENDF/B-VII Decay Data

    SciTech Connect

    Gauld, Ian C; Pigni, Marco T; Ilas, Germina

    2014-01-01

    The nuclear decay library developed for the ORIGEN code was upgraded from ENDF/B-VI.8 to -VII.0 and released in the SCALE nuclear modeling and simulation code system in 2011. Experience with the ENDF/B-VII.0 library identified serious errors and performance issues in the evaluated decay sublibrary. Initially, errors were identified in the decay scheme for the 238U series, leading to large discrepancies in the gamma emission rate for uranium. Further testing of the fission product decay data revealed significant performance issues with ENDF/B-VII.0 relative to the previous release of ENDF/B-VI. To address the performance issues, the decay data library in SCALE was upgraded to ENDF/B-VII.1 and released as an update for users in 2013. This paper describes the practical impact of the ENDF/B-VII.0 decay data performance issues on common code applications, and the validation and testing performed on the updated ORIGEN libraries developed from the ENDF/B-VII.1 sublibrary.

  3. β -delayed γ-decay of 26 P

    NASA Astrophysics Data System (ADS)

    Perez-Loureiro, David; Wrede, C.; Bennett, M. B.; Liddick, S. N.; E10034 Collaboration

    2016-03-01

    The β-decay of proton-rich nuclei is a powerful tool in nuclear science; it can be used to probe quenching of the Gamow-Teller strength, isospin asymmetries, and nuclear astrophysics. 26P β-delayed γ-decay has been recently measured at the National Superconducting Cyclotron Laboratory at MSU with much higher sensitivity than the previous experiment. A fast 26P beam produced using nuclear fragmentation was implanted into a planar germaninum detector. This detector was surrounded by the SeGA germanium array in order to detect the γ rays emitted in coincidence with β-decays with high resolution. Absolute γ-ray intensities were measured and a complete decay scheme was built for the allowed transitions to bound excited states of 26Si. Log ft values and Gamow-Teller strengths were determined for each transition and compared to shell model calculations and the β-decay of its mirror nucleus 26Na. Results of this study, including a larger Gamow-Teller quenching than the sd shell average and a substantial mirror asymmetry between the β+ and β- transitions to the first excited states of 26Si and 26Mg, respectively, will be presented and interpreted. This work is supported by the U.S. NSF under Grants PHY-1102511 and PHY-0822648, the U.S. DOE under contract DE-FG02-97ER41020 and the US NNSA under contract NA0000979.

  4. Dynamical cluster-decay model for hot and rotating light-mass nuclear systems applied to the low-energy {sup 32}S+{sup 24}Mg{yields}{sup 56}Ni{sup *} reaction

    SciTech Connect

    Gupta, Raj K.; Kumar, Rajesh; Singh, Dalip; Balasubramaniam, M.; Beck, C.

    2005-01-01

    The dynamical cluster-decay model (DCM) is developed further for the decay of hot and rotating compound nuclei (China) formed in light heavy-ion reactions. The model is worked out in terms of only one parameter, namely the neck-length parameter, which is related to the total kinetic energy TKE(T) or effective Q value Q{sub eff}(T) at temperature T of the hot CN and is defined in terms of the CN binding energy and ground-state binding energies of the emitted fragments. The emission of both the light particles (LP), with A{<=}4,Z{<=}2, as well as the complex intermediate mass fragments (IMF), with 42, is considered as the dynamical collective mass motion of preformed clusters through the barrier. Within the same dynamical model treatment, the LPs are shown to have different characteristics compared to those of the IMFs. The systematic variations of the LP emission cross section {sigma}{sub LP} and IMF emission cross section {sigma}{sub IMF} calculated from the present DCM match exactly the statistical fission model predictions. A nonstatistical dynamical description is developed for the first time for emission of light particles from hot and rotating CN. The model is applied to the decay of {sup 56}Ni* formed in the {sup 32}S+{sup 24}Mg reaction at two incident energies E{sub c.m.}=51.6 and 60.5 MeV. Both the IMFs and average TKE{sup lowbar} spectra are found to compare resonably well with the experimental data, favoring asymmetric mass distributions. The LPs' emission cross section is shown to depend strongly on the type of emitted particles and their multiplicities.

  5. RADIATIVE PENGUIN DECAYS FROM BABAR

    SciTech Connect

    Eigen, Gerald

    2003-08-28

    Electroweak penguin decays provide a promising hunting ground for Physics beyond the Standard Model (SM). The decay B {yields} X{sub s}{gamma}, which proceeds through an electromagnetic penguin loop, already provides stringent constraints on the supersymmetric (SUSY) parameter space. The present data samples of {approx}1 x 10{sup 8} B{bar B} events allow to explore radiative penguin decays with branching fractions of the order of 10{sup -6} or less. In this brief report they discuss a study of B {yields} K*{ell}{sup +}{ell}{sup -} decay modes and a search for B {yields} {rho}({omega}){gamma} decays.

  6. Charmless b decays at CDF

    SciTech Connect

    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.

  7. Towards a Conceptual Diagnostic Survey in Nuclear Physics

    ERIC Educational Resources Information Center

    Kohnle, Antje; Mclean, Stewart; Aliotta, Marialuisa

    2011-01-01

    Understanding students' prior beliefs in nuclear physics is a first step towards improving nuclear physics instruction. This paper describes the development of a diagnostic survey in nuclear physics covering the areas of radioactive decay, binding energy, properties of the nuclear force and nuclear reactions, that was administered to students at…

  8. Determination of antineutrino spectra from nuclear reactors

    SciTech Connect

    Huber, Patrick

    2011-08-15

    In this paper we study the effect of well-known higher-order corrections to the allowed {beta}-decay spectrum on the determination of antineutrino spectra resulting from the decays of fission fragments. In particular, we try to estimate the associated theory errors and find that induced currents like weak magnetism may ultimately limit our ability to improve the current accuracy and under certain circumstance could even greatly increase the theoretical errors. We also perform a critical evaluation of the errors associated with our method to extract the antineutrino spectrum using synthetic {beta} spectra. It turns out that a fit using only virtual {beta} branches with a judicious choice of the effective nuclear charge provides results with a minimal bias. We apply this method to actual data for {sup 235}U, {sup 239}Pu, and {sup 241}Pu and confirm, within errors, recent results, which indicate a net 3% upward shift in energy-averaged antineutrino fluxes. However, we also find significant shape differences which can, in principle, be tested by high-statistics antineutrino data samples.

  9. β-decay spectroscopy for the r-process nucleosynthesis

    SciTech Connect

    Nishimura, Shunji; Collaboration: RIBF Decay Collaborations

    2014-05-09

    Series of decay spectroscopy experiments, utilizing of high-purity Ge detectors and double-sided silicon-strip detectors, have been conducted to harvest the decay properties of very exotic nuclei relevant to the r-process nucleosynthesis at the RIBF. The decay properties such as β-decay half-lives, low-lying states, β-delayed neutron emissions, isomeric states, and possibly Q{sub β} of the very neutron-rich nuclei are to be measured to give significant constraints in the uncertainties of nuclear properties for the r-process nucleosynthesis. Recent results of βγ spectroscopy study using in-flight fission of {sup 238}U-beam will be presented together with our future perspectives.

  10. Theoretical description of the decay chain of the nucleus 294118

    NASA Astrophysics Data System (ADS)

    Sobiczewski, Adam

    2016-09-01

    The decay chain of the nucleus 294118, the heaviest nucleus observed (at JINR-Dubna) up to now, is analyzed theoretically. The α-decay energies {Q}α , the α-decay and the spontaneous-fission half-lives, {T}α and {T}{{sf}}, are studied. The analysis of the α decay is based on a phenomenological model using only three parameters. The calculations are performed in three variants using masses obtained with three nuclear-mass models accurately describing masses of heaviest nuclei. The experimental {Q}α energies are reconstructed with the average of the absolute values of the discrepancies: 180 keV, 270 keV and 290 keV, in the three variants considered. Measured half-lives {T}α are reproduced within the average ratios: 2.9, 9.8 and 5.2 in these variants.

  11. New approach for alpha-decay calculations of deformed nuclei

    SciTech Connect

    Ni Dongdong; Ren Zhongzhou

    2010-06-15

    We present a new theoretical approach to evaluate alpha-decay properties of deformed nuclei, namely the multichannel cluster model (MCCM). The deformed alpha-nucleus potential is taken into full account, and the coupled-channel Schroedinger equation with outgoing wave boundary conditions is employed for quasibound states. Systematic calculations are carried out for well-deformed even-even nuclei with Z>=98 and isospin dependence of nuclear potentials is included in the calculations. Fine structure observed in alpha decay is well described by the four-channel microscopic calculation, which is performed for the first time in alpha-decay studies. The good agreement between experiment and theory is achieved for both total alpha-decay half-lives and branching ratios to the ground-state rotational band of daughter nuclei. Predictions on the branching ratios to high-spin daughter states are presented for superheavy nuclei, which may be important to interpret future observations.

  12. Caustic-Side Solvent Extraction: Prediction of Cesium Extraction for Actual Wastes and Actual Waste Simulants

    SciTech Connect

    Delmau, L.H.; Haverlock, T.J.; Sloop, F.V., Jr.; Moyer, B.A.

    2003-02-01

    This report presents the work that followed the CSSX model development completed in FY2002. The developed cesium and potassium extraction model was based on extraction data obtained from simple aqueous media. It was tested to ensure the validity of the prediction for the cesium extraction from actual waste. Compositions of the actual tank waste were obtained from the Savannah River Site personnel and were used to prepare defined simulants and to predict cesium distribution ratios using the model. It was therefore possible to compare the cesium distribution ratios obtained from the actual waste, the simulant, and the predicted values. It was determined that the predicted values agree with the measured values for the simulants. Predicted values also agreed, with three exceptions, with measured values for the tank wastes. Discrepancies were attributed in part to the uncertainty in the cation/anion balance in the actual waste composition, but likely more so to the uncertainty in the potassium concentration in the waste, given the demonstrated large competing effect of this metal on cesium extraction. It was demonstrated that the upper limit for the potassium concentration in the feed ought to not exceed 0.05 M in order to maintain suitable cesium distribution ratios.

  13. 2007 Nuclear Data Review

    NASA Astrophysics Data System (ADS)

    Holden, N. E.

    2009-08-01

    The results of a review and evaluation of neutron and non-neutron nuclear data published in the scientific literature are presented. The status of new chemical elements is examined. Data on revised values for the isotopic composition of the elements are reviewed and recommended values are presented. Half-lives of very long-lived nuclides are presented, including double beta decay, double electron capture, long-lived alpha decay and long-lived beta decay. Data from new measurements on the very heavy elements (trans-meitnerium elements) are discussed and tabulated. The first observation of the radioactive decay mode of the free neutron is discussed. New measurements that have expanded the neutron drip line for magnesium and aluminum are discussed. Data on recent neutron cross-section and resonance integral measurements are also discussed.

  14. 2007 Nuclear Data Review

    SciTech Connect

    Holden,N.E.

    2008-05-05

    The results of a review and evaluation of neutron and non-neutron nuclear data published in the scientific literature are presented. The status of new chemical elements is examined. Data on revised values for the isotopic composition of the elements are reviewed and recommended values are presented. Half-lives of very long-lived nuclides are presented, including double beta decay, double electron capture, long-lived alpha decay and long-lived beta decay. Data from new measurements on the very heavy elements (trans-meitnerium elements) are discussed and tabulated. The first observation of the radioactive decay mode of the free neutron is discussed. New measurements that have expanded the neutron drip line for magnesium and aluminum are discussed. Data on recent neutron cross-section and resonance integral measurements are also discussed.

  15. 10 CFR 35.2092 - Records of decay-in-storage.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Records of decay-in-storage. 35.2092 Section 35.2092 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Records § 35.2092 Records of decay-in-storage. A licensee shall maintain records of the disposal of licensed materials, as required...

  16. 10 CFR 35.2092 - Records of decay-in-storage.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Records of decay-in-storage. 35.2092 Section 35.2092 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Records § 35.2092 Records of decay-in-storage. A licensee shall maintain records of the disposal of licensed materials, as required...

  17. 10 CFR 35.2092 - Records of decay-in-storage.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Records of decay-in-storage. 35.2092 Section 35.2092 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Records § 35.2092 Records of decay-in-storage. A licensee shall maintain records of the disposal of licensed materials, as required...

  18. 10 CFR 35.433 - Decay of strontium-90 sources for ophthalmic treatments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Decay of strontium-90 sources for ophthalmic treatments. 35.433 Section 35.433 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Manual Brachytherapy § 35.433 Decay of strontium-90 sources for ophthalmic treatments. (a) Only an authorized...

  19. 10 CFR 35.433 - Decay of strontium-90 sources for ophthalmic treatments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Decay of strontium-90 sources for ophthalmic treatments. 35.433 Section 35.433 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Manual Brachytherapy § 35.433 Decay of strontium-90 sources for ophthalmic treatments. (a) Only an authorized...

  20. 10 CFR 35.433 - Decay of strontium-90 sources for ophthalmic treatments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Decay of strontium-90 sources for ophthalmic treatments. 35.433 Section 35.433 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Manual Brachytherapy § 35.433 Decay of strontium-90 sources for ophthalmic treatments. (a) Only an authorized...

  1. 10 CFR 35.433 - Decay of strontium-90 sources for ophthalmic treatments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Decay of strontium-90 sources for ophthalmic treatments. 35.433 Section 35.433 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Manual Brachytherapy § 35.433 Decay of strontium-90 sources for ophthalmic treatments. (a) Only an authorized...

  2. 10 CFR 35.433 - Decay of strontium-90 sources for ophthalmic treatments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Decay of strontium-90 sources for ophthalmic treatments. 35.433 Section 35.433 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Manual Brachytherapy § 35.433 Decay of strontium-90 sources for ophthalmic treatments. (a) Only an authorized...

  3. Direct and indirect searches for anomalous beta decay

    NASA Astrophysics Data System (ADS)

    Nistor, Jonathan M.

    We present a treatment of time-varying nuclear transition rates intended to guide future experimental searches, focusing primarily on the concept of "self-induce decay.'' This investigation stems from a series of recent reports that suggest that the decay rates of several isotopes may have been influenced by solar activity (perhaps by solar neutrinos). A mechanism in which (anti)neutrinos can influence the decay process suggests that a sample of decaying nuclei emitting neutrinos could affect its own rate of decay. Past experiments have searched for this "self-induced decay" (SID) effect by measuring deviations from the expected decay rate for highly active samples of varying geometries. Here, we further develop a SID formalism which takes into account the activation process. In the course of the treatment, the observation is made that the SID behavior closely resembles the behavior of rate-related losses due to dead-time, and hence that standard dead-time corrections can result in the removal of possible SID-related behavior. Additionally, we discuss a long-running dark matter (DM) experiment which observes an annual signal predicted by standard DM models. Here, we consider the possibility that the annual signal seen by the DAMA collaboration, and interpreted by them as evidence for dark matter, may in fact be due to the radioactive contaminant 40K, which is known to be present in their detector. We also consider the possibility that part of the DAMA signal may arise from relic big-bang neutrinos.

  4. Nuclear Weapons, Psychology, and International Relations

    ERIC Educational Resources Information Center

    Dougherty, James E.

    1976-01-01

    Fear of nuclear energy, nuclear weapons, and nuclear was is widespread among the peoples of the world. However, to what extent do the fears (both rational and irrational) of policy-making elites and political masses produce actual effects upon the behavior of governments (who, after all, control the use of nuclear weapons)? (Author/RK)

  5. E6 Gamma Decay

    SciTech Connect

    Brown, B. Alex; Rae, W. D. M.

    2011-05-06

    Rare electric hexacontatetrapole (E6) transitions are studied in the full (f{sub 7/2},f{sub 5/2},p{sub 3/2},p{sub 1/2}) shell-model basis. Comparison of theory to the results from the gamma decay in {sup 53}Fe and from inelastic electron scattering on {sup 52}Cr provides unique and interesting tests of the valence wavefunctions, the models used for energy density functionals and into the origin of effective charge.

  6. The observation of decay

    NASA Astrophysics Data System (ADS)

    Sudbery, A.

    1984-10-01

    It is argued that the usual formulation of quantum mechanics does not satisfactorily describe physical change: the standard formula for a transition probability does not follow from the postulates. Instead, these yield the paradox that a watched pot never bolls (sometimes called "Zeno's paradox"). The paradox is reviewed and the possibility of avoiding it is discussed. A simple model of a decaying system is analysed; the system is then considered in continuous interaction with an apparatus designed to observe the time development of the system. In the light of this analysis, the possibility is considered of replacing the usual (diserete) projection postulate by a continuous projection postulate.

  7. Rare B Decays

    SciTech Connect

    Jackson, P.D.; /Victoria U.

    2006-02-24

    Recent results from Belle and BaBar on rare B decays involving flavor-changing neutral currents or purely leptonic final states are presented. Measurements of the CP asymmetries in B {yields} K*{gamma} and b {yields} s{gamma} are reported. Also reported are updated limits on B{sup +} {yields} K{sup +}{nu}{bar {nu}}, B{sup +} {yields} {tau}{sup +}{nu}, B{sup +} {yields} {mu}{sup +}{nu} and the recent measurement of B {yields} X{sub s}{ell}{sup +}{ell}{sup -}.

  8. Rare decays and CP asymmetries in charged B decays

    SciTech Connect

    Deshpande, N.G.

    1991-01-01

    The theory of loop induced rare decays and the rate asymmetry due to CP violation in charged B Decays in reviewed. After considering b {yields} s{gamma} and b {yields} se{sup +}e{sup {minus}} decays, the asymmetries for pure penguin process are estimated first. A larger asymmetry can result in those modes where a tree diagram and a penguin diagram interfere, however these estimates are necessarily model dependent. Estimates of Cabbibo suppressed penguins are also considered.

  9. Nuclear politics

    NASA Astrophysics Data System (ADS)

    Ranson, John

    2009-04-01

    The sentiments expressed by Sidney Drell in his forum article "The nuclear threat: a new start" (February pp16-17) are laudable, but it was disappointing to find this almost entirely political story in isolation. The article, which outlined the prospects for reducing weapons stockpiles under the new US administration, would have been more pertinent as an introduction to a series describing the technology used in detecting nuclear-testing activity. It would have been interesting to discuss the specific equipment and methods used, together with the analysis and correlation techniques - along with an indication of how sensitive and reliable they are (if the information is not classified). It is far easier to detect an explosive event than it is to detect and quantify weapons stores, which is a key factor for any negotiated solution. Apart from deductions based on actual inspection and satellite surveillance, are there other techniques that can be applied to this issue?

  10. Consequences of Predicted or Actual Asteroid Impacts

    NASA Astrophysics Data System (ADS)

    Chapman, C. R.

    2003-12-01

    Earth impact by an asteroid could have enormous physical and environmental consequences. Impactors larger than 2 km diameter could be so destructive as to threaten civilization. Since such events greatly exceed any other natural or man-made catastrophe, much extrapolation is necessary just to understand environmental implications (e.g. sudden global cooling, tsunami magnitude, toxic effects). Responses of vital elements of the ecosystem (e.g. agriculture) and of human society to such an impact are conjectural. For instance, response to the Blackout of 2003 was restrained, but response to 9/11 terrorism was arguably exaggerated and dysfunctional; would society be fragile or robust in the face of global catastrophe? Even small impacts, or predictions of impacts (accurate or faulty), could generate disproportionate responses, especially if news media reports are hyped or inaccurate or if responsible entities (e.g. military organizations in regions of conflict) are inadequately aware of the phenomenology of small impacts. Asteroid impact is the one geophysical hazard of high potential consequence with which we, fortunately, have essentially no historical experience. It is thus important that decision makers familiarize themselves with the hazard and that society (perhaps using a formal procedure, like a National Academy of Sciences study) evaluate the priority of addressing the hazard by (a) further telescopic searches for dangerous but still-undiscovered asteroids and (b) development of mitigation strategies (including deflection of an oncoming asteroid and on- Earth civil defense). I exemplify these issues by discussing several representative cases that span the range of parameters. Many of the specific physical consequences of impact involve effects like those of other geophysical disasters (flood, fire, earthquake, etc.), but the psychological and sociological aspects of predicted and actual impacts are distinctive. Standard economic cost/benefit analyses may not

  11. Nuclear Science References Database

    SciTech Connect

    Pritychenko, B.; Běták, E.; Singh, B.; Totans, J.

    2014-06-15

    The Nuclear Science References (NSR) database together with its associated Web interface, is the world's only comprehensive source of easily accessible low- and intermediate-energy nuclear physics bibliographic information for more than 210,000 articles since the beginning of nuclear science. The weekly-updated NSR database provides essential support for nuclear data evaluation, compilation and research activities. The principles of the database and Web application development and maintenance are described. Examples of nuclear structure, reaction and decay applications are specifically included. The complete NSR database is freely available at the websites of the National Nuclear Data Center (http://www.nndc.bnl.gov/nsr) and the International Atomic Energy Agency (http://www-nds.iaea.org/nsr)

  12. Ceramide induces early and late apoptosis in human papilloma virus+ cervical cancer cells by inhibiting reactive oxygen species decay, diminishing the intracellular concentration of glutathione and increasing nuclear factor-kappaB translocation.

    PubMed

    Gutiérrez, Gisela; Mendoza, Criselda; Montaño, Luis F; López-Marure, Rebeca

    2007-02-01

    Ceramide is regarded as an important cellular signal for the induction of cell death. We have previously shown that ceramide induces the death of cervical tumor cells without biochemical and morphological markers of apoptosis. The mechanisms by which ceramide induces cell death are not understood, therefore we evaluated the effect of C6-ceramide, a synthetic cell-permeable analog of endogenous ceramides, in signaling pathways involved in the oxidative stress of three cervical human papilloma virus cancer cell lines. Reactive oxygen species production was determined by fluorescent 2,7-dichlorofluorescein, nitrite concentration by the Griess reaction (as an indirect measure of nitric oxide production), mitochondrial membrane potential by staining with Rh123, reduced-glutathione concentration by high-pressure liquid chromatography, nuclear factor-kappaB translocation by electrophoretic mobility shift assay, inhibitory protein of nuclear factor-kappaB expression by Western blot and cell death by a poly-caspases fluorochrome-labeled inhibitors of caspases apoptosis assay. C6-ceramide induced early and late apoptosis, which was associated with an increase in reactive oxygen species and nitric oxide production, a loss in mitochondrial membrane potential, an increase in nuclear factor-kappaB translocation, and a decrease in reduced glutathione concentration. C6-ceramide did not modify the expression of inhibitory protein of nuclear factor-kappaB and its antiproliferative effect was not abrogated by Bay 11-7082, an inhibitory protein of nuclear factor-kappaB kinase inhibitor. Our results suggest that oxidative stress might participate in the ceramide-induced damage to human papilloma virus cervical cancer cells.

  13. Double beta decays of 106Cd

    NASA Astrophysics Data System (ADS)

    Suhonen, Jouni

    2011-12-01

    The two-neutrino (2ν2β) and neutrinoless (0ν2β) double beta decays of 106Cd are studied for the transitions to the ground state 0gs+ and 0+ and 2+ excited states in 106Pd by using realistic many-body wave functions calculated in the framework of the quasiparticle random-phase approximation. Effective, G-matrix-derived nuclear forces are used in realistic single-particle model spaces. All the possible channels, β+β+, β+EC, and ECEC, are discussed for both the 2ν2β and 0ν2β decays. The associated half-lives are computed and particular attention is devoted to the study of the detectability of the resonant neutrinoless double electron capture (R0νECEC) process in 106Cd. The calculations of the present article constitute the thus far most complete and up-to-date investigation of the double-beta-decay properties of 106Cd.

  14. Nuclear Data Sheets for A = 201

    SciTech Connect

    Kondev, F.G.

    2007-02-15

    Evaluated nuclear structure and decay data for all nuclei within the A = 201 mass chain are presented. This work supersedes the earlier full evaluation by M. Schmorak (1986Sc31) published in Nuclear Data Sheets 49, 733 (1986) and the update by S. Rab (1994Ra12), published in Nuclear Data Sheets 71, 421 (1994)

  15. Wood decay at sea

    NASA Astrophysics Data System (ADS)

    Charles, François; Coston-Guarini, Jennifer; Guarini, Jean-Marc; Fanfard, Sandrine

    2016-08-01

    The oceans and seas receive coarse woody debris since the Devonian, but the kinetics of wood degradation remains one of many unanswered questions about the fate of driftwood in the marine environment. A simple gravimetric experiment was carried out at a monitoring station located at the exit of a steep, forested Mediterranean watershed in the Eastern Pyrenees. The objective was to describe and quantify, with standardized logs (in shape, structure and constitution), natural degradation of wood in the sea. Results show that the mass decrease of wood logs over time can be described by a sigmoidal curve. The primary process of wood decay observed at the monitoring station was due to the arrival and installation of wood-boring species that consumed more than half of the total wood mass in six months. Surprisingly, in a region where there is little remaining wood marine infrastructure, "shipworms", i.e. xylophagous bivalves, are responsible for an important part of this wood decay. This suggests that these communities are maintained probably by a frequent supply of a large quantity of riparian wood entering the marine environment adjacent to the watershed. By exploring this direct link between terrestrial and marine ecosystems, our long term objective is to determine how these supplies of terrestrial organic carbon can sustain wood-based marine communities as it is observed in the Mediterranean Sea.

  16. Soudan nucleon decay program

    SciTech Connect

    Ayres, D.S.

    1981-01-01

    The Soudan nucleon decay program is being carried out in the Soudan iron mine in northeastern Minnesota, at a depth of 2000 m of water equivalent. A 30-ton prototype experiment, Soudan 1, has been built and is now being operated by a University of Minnesota - Argonne National Laboratory collaboration. The detector is a block of iron-loaded concrete instrumented with 3456 gas proportional tubes. It can detect nucleon decay at the 2 x 10/sup 30/ year level, and will measure cosmic-ray induced backgrounds. Soudan 1 is also obtaining data on very high energy cosmic-ray interactions. Monte-Carlo predictions of performance have been checked by calibration of a detector module in a charged-particle test beam. A proposal to build a 1000-ton experiment, Soudan 2, has been submitted to funding agencies in the USA and the UK by a Minnesota - Argonne - Oxford University collaboration. The proposed detector utilizes drift chambers with 50-cm drifts to obtain very fine-grained ionization and tracking information at low cost. This tracking-calorimeter detector has a fiducial mass of 650 tons, and could be operating in 1985. A drifting scheme utilizing 50 cm x 5 m x 1 cm planar chambers has been shown feasible, and prototypes of alternate drifting structures are also being studied. A plan to provide expandability to an eventual 5000 tons has been developed.

  17. Monticello BWR spent fuel assembly decay heat predictions and measurements

    SciTech Connect

    McKinnon, M.A.; Doman, J.W.; Heeb, C.M.; Creer, J.M.

    1986-06-01

    This report compares pre-calorimetry predictions of rates of six 7 x 7 boiling water reactor (BWR) spent fuel assemblies with measured decay heat rates. The assemblies were from Northern States Power Company's Monticello Nuclear Generating Plant and had burnups of 9 to 21 GWd/MTU and cooling times of 9 to 10 years. Conclusions are: The agreement between ORIGEN2 predictions and decay heat measurements of Monticello spent fuel is dependent on the method used to calibrate the calorimeter and to make the decay heat measurements. The agreement between predictions and measurements of decay heat rates of Monticello fuel is the same as that for Cooper and Dresden fuel if the same measurement method is used. The predictions are within a standard deviation of +-15 W of the measurements. Using a different measurement method, ORIGEN2 underpredicts the measured decay heat output of Monticello fuel assemblies by a constant 20 +- 2 W. The 20-W offset appears to be an artifact of the calibration procedure. The constant term in the calibration curve (i.e., q/sub DH/ = mx + b) can account for measurement differences of 40 W based on the 1983, 1984, and 1985 calibration curves. The difference between ORIGEN2 predictions and calorimeter decay heat measurements does not appear to be dependent on the magnitude of decay heat output. Predicted axial decay heat profiles are in good agreement with measured axial gamma radiation profiles. Recommendations are: Predictions using other decay heat codes should be compared to experimental data contained in this report, to evaluate prediction capabilities. The source of the differences that exist among calorimeter calibration curves needs to be determined. Calorimeter operational methods need to be investigated further to determine cause and effect relationships between operational method and calorimeter precision and accuracy.

  18. Nuclear Wallet Cards from the National Nuclear Data Center (NNDC)

    DOE Data Explorer

    Tuli, Jagdish K.

    Nuclear Wallet Cards present properties for ground and isomeric states of all known nuclides. Properties given are: spin and parity assignments, nuclear mass excesses, half-life, isotopic abundances, and decay modes. Appendices contain properties of elements, fundamental constants and other useful information. Nuclear Wallet Cards booklet is published by the National Nuclear Data Center and its electronic (current) version is periodically updated. The Nuclear Wallet Cards by Dr. Jagdish K. Tuli, presently in its 8th edition, is distributed in print as well as in PDA-adaptable Palm Pilot format; the data table as an ASCII file is available upon request. [Taken from http://www.nndc.bnl.gov/wallet/

  19. Alpha decay in electron surrounding

    SciTech Connect

    Igashov, S. Yu.; Tchuvil’sky, Yu. M.

    2013-12-15

    The influence of atomic electron shells on the constant of alpha decay of heavy and mediummass nuclei was considered in detail. A method for simultaneously taking into account the change in the potential-barrier shape and the effect of reflection of a diverging Coulomb wave in the classically allowed region was developed. The ratios of decay probabilities per unit time for a bare nucleus and the respective neutral atom were found for some alpha-decaying isotopes.

  20. Review of semileptonic charm decays

    SciTech Connect

    Potter, D.M.

    1991-01-01

    The experimental status of D{sup 0} and D{sup +} semileptonic decays is reviewed and compared to model predictions. Topics covered are the form factor pole mass and decay rate for D {yields} Klv, the decay rate and form factor ratios for D {yields} K*lv, and, finally, the issue of modes other than Klv and K*lv. 4 refs., 5 tabs.

  1. 40 CFR 74.22 - Actual SO2 emissions rate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Actual SO2 emissions rate. 74.22... (CONTINUED) SULFUR DIOXIDE OPT-INS Allowance Calculations for Combustion Sources § 74.22 Actual SO2 emissions... actual SO2 emissions rate shall be 1985. (2) For combustion sources that commenced operation...

  2. Actualization and the Fear of Death: Retesting an Existential Hypothesis.

    ERIC Educational Resources Information Center

    Wood, Keith; Robinson, Paul J.

    1982-01-01

    Demonstrates that within a group of highly actualized individuals, the degree to which "own death" is integrated into constructs of self is a far more powerful predictor of fear of death than actualization. Findings suggest that actualization and integration are independent in their overall effect on fear of death. (Author)

  3. Electron Screening Effects on {alpha}-decay

    SciTech Connect

    Musumarra, A.; Bonasera, A.; Del Zoppo, A.; Di Pietro, A.; Figuera, P.; Kimura, S.; Lattuada, M.; Pellegriti, M. G.; Scuderi, V.; Torresi, D.; Farinon, F.; Geissel, H.; Knoebel, R.; Prochazka, A.; Scheidenberger, C.; Nociforo, C.; Behr, K.-H.; Bosch, F.; Boutin, D.; Bruenle, A.

    2009-08-26

    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 {alpha}-decay by measuring Q-values and {alpha}-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 {sup 238}U at relativistic energies at the FRS-ESR facility at GSI. In this way it is possible to produce, efficiently separate and store highly-charged {alpha}-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 Q{sub {alpha}}-value measurements of the corresponding neutrals have been performed directly at the FRS, by implanting the separated ions into an active Silicon stopper.

  4. Beta decay of polarized neutrons

    SciTech Connect

    Bopp, P.; Dubbers, D.; Hornig, L.; Klemt, E.; Last, J.; Schuetze, H.; Freedman, S.J.; Schaerpf, O.

    1985-01-15

    Beta decay of polarized neutrons has been studied with the superconductive spectrometer PERKEO at the Institut Laue-Langevin. The energy spectrum of the ..beta..-decay asymmetry has been measured for the first time; from the absolute value of the asymmetry we obtain a new value for the ratio of weak coupling constants g/sub A//g/sub V/, which is compared to similar data from hyperon decays. The measurement of further weak interaction parameters from neutron decay is in progress.

  5. Rare B Decays at Babar

    SciTech Connect

    Palombo, Fernando; Collaboration, for the BABAR

    2009-01-12

    The author presents some of the most recent BABAR measurements for rare B decays. These include rate asymmetries in the B decays to K{sup (*)}l{sup +}l{sup -} and K{sup +}{pi}{sup -} and branching fractions in the B decays to l{sup +}{nu}{sub l}, K{sub 1}(1270){sup +}{pi}{sup -} and K{sub 1}(1400){sup +}{pi}{sup -}. The author also reports a search for the B{sup +} decay to K{sub S}{sup 0}K{sub S}{sup 0}{pi}{sup +}.

  6. Beta decay and other processes in strong electromagnetic fields

    SciTech Connect

    Akhmedov, E. Kh.

    2011-09-15

    We consider effects of the fields of strong electromagnetic waves on various characteristics of quantum processes. After a qualitative discussion of the effects of external fields on the energy spectra and angular distributions of the final-state particles as well as on the total probabilities of the processes (such as decay rates and total cross sections), we present a simple method of calculating the total probabilities of processes with production of nonrelativistic charged particles. Using nuclear {beta} decay as an example, we study the weak- and strong-field limits, as well as the field-induced {beta} decay of nuclei stable in the absence of the external fields, both in the tunneling and multiphoton regimes. We also consider the possibility of accelerating forbidden nuclear {beta} decays by lifting the forbiddeness due to the interaction of the parent or daughter nuclei with the field of a strong electromagnetic wave. It is shown that for currently attainable electromagnetic fields all effects on total {beta}-decay rates are unobservably small.

  7. Challenges in nuclear structure theory

    NASA Astrophysics Data System (ADS)

    Nazarewicz, W.

    2016-08-01

    The goal of nuclear structure theory is to build a comprehensive microscopic framework in which properties of nuclei and extended nuclear matter, and nuclear reactions and decays can all be consistently described. Due to novel theoretical concepts, breakthroughs in the experimentation with rare isotopes, increased exchange of ideas across different research areas, and the progress in computer technologies and numerical algorithms, nuclear theorists have been quite successful in solving various bits and pieces of the nuclear many-body puzzle and the prospects are exciting. This article contains a brief, personal perspective on the status of the field.

  8. Cluster decay in osmium isotopes using Hartree-Fock-Bogoliubov theory

    NASA Astrophysics Data System (ADS)

    Ashok, Nithu; Joseph, Deepthy Maria; Joseph, Antony

    2016-02-01

    Cluster radioactivity is a rare cold nuclear process which is intermediate between alpha decay and spontaneous fission. The present work is a theoretical investigation of the feasibility of alpha decay and cluster radioactivity from proton rich Osmium (Os) isotopes with mass number ranging from 162-190. Osmium forms a part of the transition region between highly deformed and spherical nuclei. Calculations have been done using unified fission model and Hartree-Fock-Bogoliubov (HFB) theory. We have chosen only those decays with half-lives falling in measurable range. Geiger-Nuttall plot has been successfully reproduced. The isotope which is most favorable to each decay mode has a magic daughter nucleus.

  9. Theory of cluster radioactive decay and of cluster formation in nuclei

    SciTech Connect

    Malik, S.S.; Gupta, R.K.

    1989-05-01

    A new model is proposed for the mechanism of cluster formation and then penetration of the confining nuclear interaction barrier in radioactive nuclei. The cluster formation is treated as a quantum-mechanical fragmentation process and the WKB penetrability is found analytically. Applications of the model are made to /sup 14/C decay of /sup 222-224/Ra and /sup 24/Ne decay of /sup 232/U. The branching ratio for /sup 14/C decay of /sup 232/U is also calculated and is found to be incredibly small as compared to that for its /sup 24/Ne decay.

  10. Probabilistic approach for decay heat uncertainty estimation using URANIE platform and MENDEL depletion code

    NASA Astrophysics Data System (ADS)

    Tsilanizara, A.; Gilardi, N.; Huynh, T. D.; Jouanne, C.; Lahaye, S.; Martinez, J. M.; Diop, C. M.

    2014-06-01

    The knowledge of the decay heat quantity and the associated uncertainties are important issues for the safety of nuclear facilities. Many codes are available to estimate the decay heat. ORIGEN, FISPACT, DARWIN/PEPIN2 are part of them. MENDEL is a new depletion code developed at CEA, with new software architecture, devoted to the calculation of physical quantities related to fuel cycle studies, in particular decay heat. The purpose of this paper is to present a probabilistic approach to assess decay heat uncertainty due to the decay data uncertainties from nuclear data evaluation like JEFF-3.1.1 or ENDF/B-VII.1. This probabilistic approach is based both on MENDEL code and URANIE software which is a CEA uncertainty analysis platform. As preliminary applications, single thermal fission of uranium 235, plutonium 239 and PWR UOx spent fuel cell are investigated.

  11. Decay of oscillating universes

    NASA Astrophysics Data System (ADS)

    Mithani, Audrey Todhunter

    It has been suggested by Ellis et al that the universe could be eternal in the past, without beginning. In their model, the "emergent universe'' exists forever in the past, in an "eternal'' phase before inflation begins. We will show that in general, such an "eternal'' phase is not possible, because of an instability due to quantum tunneling. One candidate model, the "simple harmonic universe'' has been shown by Graham et al to be perturbatively stable; we find that it is unstable with respect to quantum tunneling. We also investigate the stability of a distinct oscillating model in loop quantum cosmology with respect to small perturbations and to quantum collapse. We find that the model has perturbatively stable and unstable solutions, with both types of solutions occupying significant regions of the parameter space. All solutions are unstable with respect to collapse by quantum tunneling to zero size. In addition, we investigate the effect of vacuum corrections, due to the trace anomaly and the Casimir effect, on the stability of an oscillating universe with respect to decay by tunneling to the singularity. We find that these corrections do not generally stabilize an oscillating universe. Finally, we determine the decay rate of the oscillating universe. Although the wave function of the universe lacks explicit time dependence in canonical quantum cosmology, time evolution may be present implicitly through the semiclassical superspace variables, which themselves depend on time in classical dynamics. Here, we apply this approach to the simple harmonic universe, by extending the model to include a massless, minimally coupled scalar field φ which has little effect on the dynamics but can play the role of a "clock''.

  12. Use of standards in nuclear analytical chemistry at ORNL - a historical perspective

    SciTech Connect

    Dyer, F.F.

    1994-12-31

    Standards, the glue that holds empirical science together, have long been recognized as important in nuclear analytical chemistry at Oak Ridge National Laboratory (ORNL). From the earliest days of the nuclear analytical program at ORNL, personnel have been vigorously involved with the evaluation of decay schemes and half-lives to improve radioactive standards. One of the more interesting uses of standards at ORNL was in the Apollo program, where radionuclides were determined in moon rocks by measuring samples containing known amounts of radionuclides that simulated the actual samples in size and shape. This paper briefly reviews some of the early uses of standards at ORNL and contrasts the application of standards in some current work in multielement neutron activation analysis (NAA) that uses germanium gamma-ray detectors with similar work that was performed in the 1960s that made use of NaI(Tl) detectors.

  13. Selected spectroscopic results on element 115 decay chains

    SciTech Connect

    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.; Herzberg, R. -D.; Heßberger, F. P.; 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.

    2014-08-24

    We observed thirty correlated α-decay chains in an experiment studying the fusion-evaporation reaction 48Ca + 243Am at the GSI Helmholtzzentrum fur Schwerionenforschung. The decay characteristics of the majority of these 30 chains are consistent with previous observations and interpretations of such chains to originate from isotopes of element Z = 115. High-resolution α-photon coincidence spectroscopy in conjunction with comprehensive Monte-Carlo simulations allow to propose excitation schemes of atomic nuclei of the heaviest elements, thereby probing nuclear structure models near the 'Island of Stability' with unprecedented experimental precision.

  14. Selected spectroscopic results on element 115 decay chains

    DOE PAGES

    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.; et al

    2014-08-24

    We observed thirty correlated α-decay chains in an experiment studying the fusion-evaporation reaction 48Ca + 243Am at the GSI Helmholtzzentrum fur Schwerionenforschung. The decay characteristics of the majority of these 30 chains are consistent with previous observations and interpretations of such chains to originate from isotopes of element Z = 115. High-resolution α-photon coincidence spectroscopy in conjunction with comprehensive Monte-Carlo simulations allow to propose excitation schemes of atomic nuclei of the heaviest elements, thereby probing nuclear structure models near the 'Island of Stability' with unprecedented experimental precision.

  15. Microscopic beta and gamma data for decay-heat needs

    SciTech Connect

    Dickens, J.K.

    1983-01-01

    Microscopic beta and gamma data for decay-heat needs are defined as absolute-intensity spectral distributions of beta and gamma rays following radioactive decay of radionuclides created by, or following, the fission process. Four well-known evaluated data files, namely the US ENDF/B-V, the UK UKFPDD-2, the French BDN (for fission products), and the Japanese JNDC Nuclear Data Library, are reviewed. Comments regarding the analyses of experimental data (particularly gamma-ray data) are given; the need for complete beta-ray spectral measurements is emphasized. Suggestions on goals for near-term future experimental measurements are presented. 34 references.

  16. NUCLEAR DATA REVIEW

    SciTech Connect

    HOLDEN,N.E.

    2004-12-01

    Non-neutron nuclear data are periodically reviewed and evaluated. The recommended values are published in the Table of the Isotopes of the Chemical Rubber Company's Handbook of Chemistry and Physics. A 2004 review has begun to re-examine some data of interest to the International Union of Geological Sciences (IUGS) sub-commission on Geochronology dealing with radioactive decay constants and isotopic abundance ratios. Among the decay constants that are being evaluated are those of the following nuclides: {sup 40}K, {sup 87}Rb, {sup 138}La, {sup 147}Sm, {sup 176}Lu, {sup 174}Hf, {sup 187}Re, {sup 190}Pt, {sup 232}Th, {sup 235}U, {sup 238}U.

  17. Nuclear Structure Aspects in Nuclear Astrophysics

    SciTech Connect

    Smith, Michael Scott

    2006-12-01

    Nuclear Astrophysics as a broad and diverse field of study can be viewed as a magnifier of the impact of microscopic processes on the evolution of macroscopic events. One of the primary goals in Nuclear Astrophysics is the understanding of the nucleosynthesis processes that take place in the cosmos and the simulation of the correlated stellar and explosive burning scenarios. These simulations are strongly dependent on the input from Nuclear Physics which sets the time scale for all stellar dynamic processes--from giga-years of stellar evolution to milliseconds of stellar explosions--and provides the basis for most of the signatures that we have for the interpretation of these events--from stellar luminosities, elemental and isotopic abundances to neutrino flux from distant supernovae. The Nuclear Physics input comes through nuclear structure, low energy reaction rates, nuclear masses, and decay rates. There is a common perception that low energy reaction rates are the most important component of the required nuclear physics input; however, in this article we take a broader approach and present an overview of the close correlation between various nuclear structure aspects and their impact on nuclear astrophysics. We discuss the interplay between the weak and the strong forces on stellar time scales due to the limitations they provide for the evolution of slow and rapid burning processes. The effects of shell structure in nuclei on stellar burning processes as well as the impact of clustering in nuclei is outlined. Furthermore we illustrate the effects of the various nuclear structure aspects on the major nucleosynthesis processes that have been identified in the last few decades. We summarize and provide a coherent overview of the impact of all aspects of nuclear structure on nuclear astrophysics.

  18. Nuclear data sheets for A = 244

    SciTech Connect

    Chukreev, F. E.; Shurshikov, E. N.; Bodulinskij, V. K.; Jaborov, J. F.; Hovanovich, A. I.

    1981-11-01

    Detailed level and decay schemes and the experimental reaction and decay data on which they are based are presented for all nuclei with mass number A = 244; the experimental data are evaluated. Adopted values for level and ..gamma..-ray energies, ..gamma..-intensities, as well as other nuclear properties are given.

  19. Counterflow driven by swirl decay

    NASA Astrophysics Data System (ADS)

    Shtern, Vladimir N.; Borissov, Anatoli A.

    2010-06-01

    The global meridional circulation of a viscous fluid, caused by swirl decay in a cylindrical container, is studied. To this end, a new solution to the Navier-Stokes equations is obtained, and simple experiments are performed to verify the predictions of the theory. The swirl decay mechanism explains elongated counterflows in hydrocyclones and vortex tubes sometimes extending over a hundred diameters.

  20. Status of rare decay experiments

    SciTech Connect

    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)

  1. Particle decay in inflationary cosmology

    SciTech Connect

    Boyanovsky, D.; Vega, H.J. de

    2004-09-15

    We investigate the relaxation and decay of a particle during inflation by implementing the dynamical renormalization group. This investigation allows us to give a meaningful definition for the decay rate in an expanding universe. As a prelude to a more general scenario, the method is applied here to study the decay of a particle in de Sitter inflation via a trilinear coupling to massless conformally coupled particles, both for wavelengths much larger and much smaller than the Hubble radius. For superhorizon modes we find that the decay is of the form {eta}{sup {gamma}{sub 1}} with {eta} being conformal time and we give an explicit expression for {gamma}{sub 1} to leading order in the coupling which has a noteworthy interpretation in terms of the Hawking temperature of de Sitter space-time. We show that if the mass M of the decaying field is <decay rate during inflation is enhanced over the Minkowski space-time result by a factor 2H/{pi}M. For wavelengths much smaller than the Hubble radius we find that the decay law is e with C({eta}) the scale factor and {alpha} determined by the strength of the trilinear coupling. In all cases we find a substantial enhancement in the decay law as compared to Minkowski space-time. These results suggest potential implications for the spectrum of scalar density fluctuations as well as non-Gaussianities.

  2. Nuclear data sheets for A = 210

    SciTech Connect

    Harmatz, B.

    1981-01-01

    Nuclear structure information pertaining to A = 210 has been reviewed. The level properties obtained from decay and reaction experiments are shown in the drawings. Experimental methods, references, and comment are given in the text.

  3. Nuclear data sheets for A = 217

    SciTech Connect

    Akovali, Y. A.

    1991-06-01

    The available nuclear structure information for all nuclei with mass number A = 217 is presented. Various decay and reaction data are evaluated and compared. Adopted data, levels, and spin and parity assignments are given.

  4. Nuclear data sheets for A = 226

    SciTech Connect

    Akovali, Y. A.

    1996-02-01

    The available nuclear structure information for all nuclei with mass number A = 226 is presented. Various decay and reaction data are evaluated and compared. Adopted data, levels, spin, parity and configuration assignments are given. 134 refs.

  5. Nuclear data sheets for A = 218

    SciTech Connect

    Ellis-Akovali, Y. A.

    1987-12-01

    The available nuclear structure information for all nuclei with mass number A = 218 is presented. Various decay and reaction data are evaluated and compared. Adopted data, levels, spin and parities are given. copyright 1987 Academic Press, Inc.

  6. Nuclear data sheets update for A = 218

    SciTech Connect

    Akovali, Y. A.

    1995-11-01

    The available nuclear structure information for all nuclei with mass number A = 218 is presented. Various decay and reaction data are evaluated and compared. Adopted data, levels, spin, parity and configuration assignments are given.

  7. Nuclear data sheets update for A = 204

    SciTech Connect

    Schmorak, M. R.

    1994-07-01

    Experimental data pertaining to nuclear structure of nuclei with mass number A = 204 have been compiled and evaluated. A summary of information obtained in various reaction and decay experiments is presented, together with the adopted level schemes.

  8. Nuclear Data Sheets for A = 214

    SciTech Connect

    Akovali, Y. A.

    1988-12-01

    The available nuclear structure information for all nuclei with mass number A = 214 is presented. Various decay and reaction data are evaluated and compared. Adopted data, levels, spin and parities are given.

  9. Nuclear data sheets for A = 222

    SciTech Connect

    Akovali, Y. A.

    1996-01-01

    The available nuclear structure information for all nuclei with mass number A = 222 is presented. Various decay and reaction data are evaluated and compared. Adopted data, levels, spin, parity, and configuration assignments are given. 201 refs.

  10. Nuclear data sheets for A = 206

    SciTech Connect

    Browne, E.

    1999-09-01

    This evaluation presents data for all nuclei with mass number A=206, which includes level schemes deduced from radioactive decay and nuclear reaction studies. All data received by August 1999 were evaluated.

  11. Nuclear data sheets update for A = 201

    SciTech Connect

    Rab, Shaheen

    1994-02-01

    The experimental nuclear structure and decay data of ten nuclei of mass 201 (Pt, Au, Hg, Tl, Pb, Bi, Po, At, Rn, Fr) have been evaluated. Adopted levels and gammas for each of these nuclei have also been prepared.

  12. Nuclear Data Sheets for A = 148

    DOE PAGES

    Nica, N.

    2014-04-02

    The experimental nuclear structure data available through October 2013 have been reviewed. A summary of information obtained in various reaction and decay experiments is presented, together with adopted level schemes.

  13. Top decays in extended models

    SciTech Connect

    Gaitan, R.; Miranda, O. G.; Cabral-Rosetti, L. G.

    2009-04-20

    Top quark decays are interesting as a mean to test the Standard Model (SM) predictions. The Cabbibo-Kobayashi-Maskawa (CKM)-suppressed process t{yields}cWW, and the rare decays t{yields}cZ, t{yields}H{sup 0}+c, and t{yields}c{gamma} an excellent window to probe the predictions of theories beyond the SM. We evaluate the flavor changing neutral currents (FCNC) decay t{yields}H{sup 0}+c in the context of Alternative Left-Right symmetric Models (ALRM) with extra isosinglet heavy fermions; the FCNC decays may place at tree level and are only supressed by the mixing between ordinary top and charm quarks. We also comment on the decay process t{yields}c+{gamma}, which involves radiative corrections.

  14. Spectral decomposition of phosphorescence decays.

    PubMed

    Fuhrmann, N; Brübach, J; Dreizler, A

    2013-11-01

    In phosphor thermometry, the fitting of decay curves is a key task in the robust and precise determination of temperatures. These decays are generally assumed to be mono-exponential in certain temporal boundaries, where fitting is performed. The present study suggests a multi-exponential method to determine the spectral distribution in terms of decay times in order to analyze phosphorescence decays and thereby complement the mono-exponential analysis. Therefore, two methods of choice are compared and verified using simulated data in the presence of noise. Addtionally, this spectral decomposition is applied to the thermographic phosphor Mg4FGeO6 : Mn and reveals changes in the exponential distributions of decay times upon a change of the excitation laser energy.

  15. Fine structure of cluster decays

    SciTech Connect

    Dumitrescu, O.

    1994-03-01

    Within the one level {ital R}-matrix approach, expressions are derived for the hindrance factors of cluster radioactive decays in which {ital y} {ital the} {ital shell} {ital model} {ital with} {ital effective} {ital residual} {ital interactions} [{ital e}.{ital g}.,{ital thelar} in the Michigan State University version for nearly spherical nuclei, or the enlarged superfluid model (ESM) recently proposed for deformed nuclei]. The exterior wave functions are calculated from a cluster-nucleus double-folding model potential obtained with the M3Y interaction. As examples of the cluster decay fine structure we analyzed the particular cases of {alpha} decay of {sup 241}Am and {sup 243}Cm, {sup 14}C decay of {sup 223}Ra, and {sup 34}Si decay of {sup 243}Cm. Good agreement with the experimental data is obtained.

  16. α -decay chains of recoiled superheavy nuclei: A theoretical study

    NASA Astrophysics Data System (ADS)

    Niyti, Sawhney, Gudveen; Sharma, Manoj K.; Gupta, Raj K.

    2015-05-01

    A systematic theoretical study of α -decay half-lives in the superheavy mass region of the periodic table of elements is carried out by extending the quantum-mechanical fragmentation theory based on the preformed cluster model (PCM) to include temperature (T ) dependence in its built-in preformation and penetration probabilities of decay fragments. Earlier, the α -decay chains of the isotopes of Z =115 were investigated by using the standard PCM for spontaneous decays, with"hot-optimum" orientation effects included, which required a constant scaling factor of 104 to approach the available experimental data. In the present approach of the PCM (T ≠0 ), the temperature effects are included via the recoil energy of the residual superheavy nucleus (SHN) left after x -neutron emission from the superheavy compound nucleus. The important result is that the α -decay half-lives calculated by the PCM (T ≠0 ) match the experimental data nearly exactly, without using any scaling factor of the type used in the PCM. Note that the PCM (T ≠0 ) is an equivalent of the dynamical cluster-decay model for heavy-ion collisions at angular momentum ℓ =0 . The only parameter of model is the neck-length parameter Δ R , which for the calculated half-lives of α -decay chains of various isotopes of Z =113 to 118 nuclei formed in "hot-fusion" reactions is found to be nearly constant, i.e., Δ R ≈0.95 ±0.05 fm for all the α -decay chains studied. The use of recoiled residue nucleus as a secondary heavy-ion beam for nuclear reactions has also been suggested in the past.

  17. Search for two-neutrino double-β decay of 96Zr to excited states of 96Mo

    NASA Astrophysics Data System (ADS)

    Finch, S. W.; Tornow, W.

    2015-10-01

    Background: Double-β decay is a rare second-order nuclear decay. The importance of this decay stems from the possibility of neutrinoless double-β decay and its applications to neutrino physics. Purpose: A search was conducted for the 2 ν β β decay of 96Zr to excited final states of the daughter nucleus, 96Mo. Measurements of this decay are important to test nuclear matrix element calculations, which are necessary to extract the neutrino mass from a measurement of the neutrinoless double-β decay half-life. Method: Two coaxial high-purity germanium detectors were used in coincidence to detect γ rays produced by the daughter nucleus as it de-excited to the ground state. The experiment was carried out at the Kimballton Underground Research Facility and produced 685.7 d of data with a 17.91 g enriched sample. Results: No counts were seen above background. For the decay to the first excited 0+ state, a limit of T1 /2>3.1 ×1020 yr was produced. Limits to higher excited states are also reported. Conclusion: The new limits on double-β decay are an improvement over previous experiments by a factor of 2 to 5 for the various excited states. The nuclear matrix element for the double-β decay to the first excited 0+ state is found to be <0.13 .

  18. Nuclear data sheets update for A = 198

    SciTech Connect

    Chunmei, Zhou

    1995-02-01

    The 1990 version of nuclear data sheets for A = 198 has been updated on the basis of decay and reaction experiments, which lead to nuclei in the A = 198 mass chain. The data sets of experimental reaction and decay studies are presented in the drawings or tables. The adopted values of levels and their {gamma}-radiations, and as well as other nuclear properties are presented in tables. The experimental methods, references, and comments are given in the text.

  19. Nuclear Data Sheets for A=69

    SciTech Connect

    Nesaraja, C.D.

    2014-01-15

    Experimental data on ground– and excited–state properties for all known nuclei with mass number A=69 have been compiled and evaluated. States populated in radioactive decay, as well as in nuclear reactions, have been considered. For these nuclei, level and decay schemes, as well as tables of nuclear properties, are given in detail. This work supersedes the 2000 evaluation by M.R. Bhat and J.K. Tuli (2000Bh05)

  20. Nuclear Data Sheets for A=69

    SciTech Connect

    Nesaraja, Caroline D

    2014-01-01

    Experimental data on ground- and excited-state properties for all known nuclei with mass number A=69 have been compiled and evaluated. States populated in radioactive decay, as well as in nuclear reactions, have been considered. For these nuclei, level and decay schemes, as well as tables of nuclear properties, are given in detail. This work supersedes the 2000 evaluation by M.R.Bhat and J.K.Tuli (2000Bh05).

  1. Meson's correlation functions in a nuclear medium

    NASA Astrophysics Data System (ADS)

    Park, Chanyong

    2016-09-01

    We investigate meson's spectrum, decay constant and form factor in a nuclear medium through holographic two- and three-point correlation functions. To describe a nuclear medium composed of protons and neutrons, we consider a hard wall model on the thermal charged AdS geometry and show that due to the isospin interaction with a nuclear medium, there exist splittings of the meson's spectrum, decay constant and form factor relying on the isospin charge. In addition, we show that the ρ-meson's form factor describing an interaction with pseudoscalar fluctuation decreases when the nuclear density increases, while the interaction with a longitudinal part of an axial vector meson increases.

  2. Primordial nucleosynthesis with decaying particles. I - Entropy-producing decays. II - Inert decays

    NASA Technical Reports Server (NTRS)

    Scherrer, Robert J.; Turner, Michael S.

    1988-01-01

    The effect of a nonrelativistic particle X, which decays out of equilibrium, on primordial nucleosynthesis is investigated, including both the energy density of the X particle and the electromagnetic entropy production from its decay. The results are parametrized in terms of the X particle lifetime and the density parameter rm(X), where m(X) is the X particle mass and r is the ratio of X number density to photon number density prior to nucleosynthesis. The results rule out particle lifetimes greater than 1-10 s for large values of rm(X). The question of a decaying particle which produces no electromagnetic entropy in the course of its decay is addressed, and particles which produce both entropy and an inert component in their decay are discussed.

  3. Concentrations of 222Rn, 220Rn and their decay products measured in outdoor air in various rural zones (Morocco) by using solid-state nuclear track detectors and resulting radiation dose to the rural populations.

    PubMed

    Misdaq, M A; Amrane, M; Ouguidi, J

    2010-03-01

    Alpha and beta activities per unit volume of air due to radon ((222)Rn), thoron ((220)Rn) and their progenies were measured in the outdoor air at different locations in Morocco by using both CR-39 and LR-115 type II solid-state nuclear track detectors (SSNTDs). In addition, the radon concentration was continuously measured in one location by using the methods with SSNTDs and AlphaGuard counter. The influence of the geological and meteorological conditions as well as phosphate and building material dust on the radon concentration in the outdoor air of the areas studied was investigated. The committed equivalent doses due to (218)Po and (214)Po radon short-lived progeny were evaluated in different tissues of the respiratory tract of the members of the public from the inhalation of outdoor air. The annual effective dose due to radon short-lived progeny from the inhalation of outdoor air by the members of the rural population was estimated.

  4. Summary remarks and future prospects for on-line nuclear orientation

    SciTech Connect

    Krane, K.S.; Hamilton, J.H.

    1984-01-01

    Results from various groups which use on-line low temperature nuclear orientation techniques are presented. Several nuclear parameters have been successfully studied: rotational levels, nuclear deformation, and decay modes. Future prospects include multiparameter analysis, relaxation and pre-orientation, new separators, and alpha decay studies. 33 refs., 5 figs. (WRF)

  5. Effects of Decay of Incorporated H3-Thymidine on Bacteria

    PubMed Central

    Person, Stanley; Leah Lewis, Hazel

    1962-01-01

    The killing efficiency due to the decay of incorporated H3-thymidine in three mutants of E. coli strain 15: 15T-, 15T-L-, and 15T-U- has been determined. This efficiency is comparable to that previously determined by others for P32 decay. The killing efficiency has been determined as a function of H3-thymidine specific activity, storage media and storage temperature. We have observed a latent killing effect that causes lethality under certain conditions. The kinetics of latent killing have been examined at several temperatures. Finally, mutation production induced by H3-thymidine decays was shown to occur. The results are consistent with the idea that inactivation and mutations may be caused by a process in the nuclear transmutation that is not associated with β-particle ionization damage. PMID:19431318

  6. - and -delayed neutron- decay of neutron-rich copper isotopes

    SciTech Connect

    Korgul, A.; Rykaczewski, Krzysztof Piotr; Winger, J. A.; Ilyushkin, S.; Gross, Carl J; Batchelder, J. C.; Bingham, C. R.; Borzov, Ivan N; Goodin, C.; Grzywacz, Robert Kazimierz; Hamilton, Joseph H; Krolas, W.; Liddick, S. N.; Mazzocchi, C.; Nelson, C.; Nowacki, F.; Padgett, Stephen; Piechaczek, A.; Rajabali, M. M.; Shapira, Dan; Sieja, K.; Zganjar, E. F.

    2012-01-01

    The {beta}-decay properties of neutron-rich Cu isotopes produced in proton-induced fission of {sup 238}U were studied at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. The data were collected using high-resolution online mass separation, reacceleration, and digital {beta}-{gamma} spectroscopy methods. An improved decay scheme of N = 49 {sup 78}Cu and the first observation of N = 50 {sup 79}Cu {beta}-delayed neutron decay followed by a gamma transition are reported. Spin and parity (5{sup -}) are deduced for {sup 78gs}Cu. The {beta}-delayed neutron branching ratios (P{sub {beta}n}) for the {sup 77}Cu and {sup 79}Cu precursors are analyzed with the help of nuclear structure models.

  7. β -delayed fission and α decay of 196At

    NASA Astrophysics Data System (ADS)

    Truesdale, V. L.; Andreyev, A. N.; Ghys, L.; Huyse, M.; Van Duppen, P.; Sels, S.; Andel, B.; Antalic, S.; Barzakh, A.; Capponi, L.; Cocolios, T. E.; Derkx, X.; De Witte, H.; Elseviers, J.; Fedorov, D. V.; Fedosseev, V. N.; Heßberger, F. P.; Kalaninová, Z.; Köster, U.; Lane, J. F. W.; Liberati, V.; Lynch, K. M.; Marsh, B. A.; Mitsuoka, S.; Nagame, Y.; Nishio, K.; Ota, S.; Pauwels, D.; Popescu, L.; Radulov, D.; Rapisarda, E.; Rothe, S.; Sandhu, K.; Seliverstov, M. D.; Sjödin, A. M.; Van Beveren, C.; Van den Bergh, P.; Wakabayashi, Y.

    2016-09-01

    A nuclear-decay spectroscopy study of the neutron-deficient isotope 196At is reported where an isotopically pure beam was produced using the selective Resonance Ionization Laser Ion Source and On-Line Isotope Mass Separator (CERN). The fine-structure α decay of 196At allowed the low-energy excited states in the daughter nucleus 192Bi to be investigated. A β -delayed fission study of 196At was also performed. A mixture of symmetric and asymmetric fission-fragment mass distributions of the daughter isotope 196Po (populated by β decay of 196At) was deduced based on the measured fission-fragment energies. A β DF probability Pβ DF(196At) =9 (1 ) ×10-5 was determined.

  8. Radionuclide Decay and In-growth Technical Basis Document

    SciTech Connect

    Kersting, A B; Finnegan, D L; Tompson, A F B; Esser, B K; Smith, D K; Zavarin, M; Bruton, C J; Pawloski, G A

    2003-07-01

    The purpose of this report is to assess the decay and in-growth of radionuclides from the radionuclide source term (RST) deposited by underground nuclear weapons tests conducted at the NTS from 1951 through 1992. A priority of the Underground Test Area (UGTA) project, administered by the Environmental Restoration Division of NNSA/NV, was to determine as accurately as possible a measure of the total radionuclide inventory for calculation of the RST deposited in the subsurface at the Nevada Test Site (NTS). The motivation for the development of a total radionuclide inventory is driven by a need to calculate the amount of radioactivity that will move away from the nuclear test cavities over time, referred to as the hydrologic source term (HST). The HST is a subset of the RST and must be calculated using knowledge of the geochemistry and hydrology of the subsurface environment. This will serve the regulatory process designed to protect human health from exposures to contaminated groundwater. Following the detonation of an underground nuclear test, and depending on the presence of water at the location of the detonation, the residual radionuclides may be found in aqueous or gaseous states, precipitated or chemically sorbed states, or incorporated in melt glass produced by the nuclear test. The decay and in-growth of radionuclides may have geochemical implications for the migration of radionuclides away from underground nuclear test cavities. For example, in the case of a long-lived mobile parent decaying to a shorter-lived and less mobile daughter, the geochemical properties of the parent element may control the migration potential of the daughter nuclide. It becomes important to understand the evolution of the RST in terms of effects on the mobility, solubility, or abundance of radionuclides in the HST that are created by decay and in-growth processes. The total radionuclide inventory and thus the RST changes with time due to radioactive decay. The abundance of a

  9. Relationship between perceived and actual motor competence among college students.

    PubMed

    Wang, Jianyu; Liu, Wenhao; Bian, Wei

    2013-02-01

    The relationship between perceived and actual motor competence was examined among college students. Participants were 114 college students (55 men, 59 women; M age = 22.3 yr., SD = 3.9). All participants completed a short survey on perception of motor competence in basketball and took a Control Basketball Dribble Test to assess their actual motor skill. Perceived motor competence in basketball was significantly related to basketball dribbling performance. Given the positive relationship between actual motor competence and perceived competence, enhancing an individual's actual motor competence may contribute to their perceived competence, which may improve an individual's physical activity participation.

  10. Optimizing VANDLE for Decay Spectroscopy

    NASA Astrophysics Data System (ADS)

    Brewer, N. T.; Taylor, S. Z.; Grzywacz, R.; Madurga, M.; Paulauskas, S. V.; Cizewski, J. A.; Peters, W. A.; Vandle Collaboration

    2013-10-01

    Understanding the decay properties of neutron rich isotopes has well established importance to the path of the r-process and to the total decay heat for reactor physics. Specifically, the half-life, branching ratio and spectra for β-n decay is of particular interest. With that in mind, we have continued attempts to improve upon the Versatile Array of Neutron Detectors at Low Energy (VANDLE) in terms of efficiency and TOF resolution through the use of new and larger scintillators. Details of the new implementation, design and characterization of the array will be shown and compared to previous results.

  11. Radiative Leptonic B Decays

    SciTech Connect

    Chen, Edward Tann

    2007-01-01

    We present the results of a search for B+ meson decays into γℓ+v, where ℓ = e,μ. We use a sample of 232 million B$\\bar{B}$ meson pairs recorded at the Υ(4S) resonance with the BABAR detector at the PEP-II B factory. We measure a partial branching fraction Δβ in a restricted region of phase space that reduces the effect of theoretical uncertainties, requiring the lepton energy to be in the range 1.875 and 2.850 GeV, the photon energy to be in the range 0.45 and 2.35 GeV, and the cosine of the angle between the lepton and photon momenta to be less than -0.36, with all quantities computed in the Υ(4S) center-of-mass frame. We find Δβ(B+ → γℓ+v) = (-0.31.5+1.3(statistical) -0.6+0.6(systematic) ± 0.1(theoretical)) x 10-6, under the assumption of lepton universality. Interpreted as a 90% confidence-level Bayesian upper limit, the result corresponds to 1.7 x 10-6 for a prior at in amplitude, and 2.3 x 10-6 for a prior at in branching fraction.

  12. RARE DECAYS INCLUDING PENGUINS

    SciTech Connect

    Eigen, G

    2003-12-04

    The authors present a preliminary measurement of the exclusive charmless semileptonic B decays, B {yields} {rho}{ell}{nu}, and the extraction of the CKM parameters V{sub ub}. IN a data sample of 55 x 10{sup 6} B{bar B} events they measure a branching fraction of {Beta}(B {yields} {rho}{ell}{nu}) = (3.39 {+-} 0.44{sub stat} {+-} 0.52{sub sys} {+-} 0.60{sub th}) x 10{sup -4} yielding |V{sub ub}| = (3.69 {+-} 0.23{sub stat} {+-} 0.27{sub sys -0.59th}{sup +0.40}) x 10{sup -3}. Next, they report on a preliminary study of the radiative penguin modes B {yields} K{ell}{sup +}{ell}{sup -} and B {yields} K*{ell}{sup +}{ell}{sup -}. In a data sample of 84 x 10{sup 6} B{bar B} events they observe a significant signal (4.4{sigma}) in B {yields} K{ell}{sup +}{ell}{sup -}, yielding a branching fraction of {Beta}(B {yields} K{ell}{sup +}{ell}{sup -}) = (0.78{sub -0.20-0.18}{sup +0.24+0.11}) x 10{sup -6}. In B {yields} K*{ell}{sup +}{ell}{sup -} the observed yield is not yet significant (2.8{sigma}), yielding an upper limit of the branching fraction of {Beta}(B {yields} K*{ell}{sup +}{ell}{sup -}) 3.0 x 10{sup -6} {at} 90% confidence level. Finally, they summarize preliminary results of searches for B {yields} {rho}({omega}){gamma}, B{sup +} {yields} K{sup +} {nu}{bar {nu}} and B{sup 0} {yields} {ell}{sup +}{ell}{sup -}.

  13. Majorana neutrino masses and the neutrinoless double-beta decay

    SciTech Connect

    Faessler, A.

    2006-12-15

    Neutrinoless double-beta decay is forbidden in the Standard Model of electroweak and strong interaction but allowed in most Grand Unified Theories (GUTs). Only if the neutrino is a Majorana particle (identical with its antiparticle) and if it has a mass is neutrinoless double-beta decay allowed. Apart from one claim that the neutrinoless double-beta decay in {sup 76}Ge is measured, one has only upper limits for this transition probability. But even the upper limits allow one to give upper limits for the electron Majorana neutrino mass and upper limits for parameters of GUTs and the minimal R-parity-violating supersymmetric model. One further can give lower limits for the vector boson mediating mainly the right-handed weak interaction and the heavy mainly right-handed Majorana neutrino in left-right symmetric GUTs. For that, one has to assume that the specific mechanism is the leading one for neutrinoless double-beta decay and one has to be able to calculate reliably the corresponding nuclear matrix elements. In the present work, one discusses the accuracy of the present status of calculating of the nuclear matrix elements and the corresponding limits of GUTs and supersymmetric parameters.

  14. Quantifying the genomic decay paradox due to Muller's ratchet in human mitochondrial DNA.

    PubMed

    Loewe, Laurence

    2006-04-01

    The observation of high mitochondrial mutation rates in human pedigrees has led to the question of how such an asexual genetic system can survive the accumulation of slightly deleterious mutations caused by Muller's ratchet. I define a null model to quantify in unprecedented detail the threat from extinction caused by Muller's ratchet. This model is general enough to explore the biological significance of Muller's ratchet in various species where its operation has been suspected. For increased precision over a wide range of parameter space I employ individual-based simulations run by evolution@home, the first global computing system for evolutionary biology. After compiling realistic values for the key parameters in human mitochondrial DNA (mtDNA) I find that a surprisingly large range of biologically realistic parameter combinations would lead to the extinction of the human line over a period of 20 million years - if accepted wisdom about mtDNA and Muller's ratchet is correct. The resulting genomic decay paradox complements a similar threat from extinction due to mutation accumulation in nuclear DNA and suggests evaluation of unconventional explanations for long-term persistence. A substantial list of potential solutions is given, including compensatory back mutations, mutation rate heterogeneity and occasional recombination in mtDNA. Future work will have to explore which of these actually solves the paradox. Nonetheless, the results presented here provide yet another reason to minimize anthropogenic increase of mutation rates.

  15. Evaluated nuclear structure data file

    NASA Astrophysics Data System (ADS)

    Tuli, J. K.

    The Evaluated Nuclear Structure Data File (ENSDF) contains the evaluated nuclear properties of all known nuclides. These properties are derived both from nuclear reaction and radioactive decay measurements. All experimental data are evaluated to create the adopted properties for each nuclide. ENSDF, together with other numeric and biographic files, can be accessed on-line through the INTERNET or modem. Some of the databases are also available on the World Wide Web. The structure and the scope of ENSDF are presented along with the on-line access system of the National Nuclear Data Center at Brookhaven National Laboratory.

  16. Evaluated nuclear structure data file

    NASA Astrophysics Data System (ADS)

    Tuli, J. K.

    1996-02-01

    The Evaluated Nuclear Structure Data File (ENSDF) contains the evaluated nuclear properties of all known nuclides, as derived both from nuclear reaction and radioactive decay measurements. All experimental data are evaluated to create the adopted properties for each nuclide. ENSDF, together with other numeric and bibliographic files, can be accessed on-line through the INTERNET or modem, and some of the databases are also available on the World Wide Web. The structure and the scope of ENSDF are presented along with the on-line access system of the National Nuclear Data Center at Brookhaven National Laboratory.

  17. Total Absorption Spectroscopy of the 137Xe, 137I, and 92Rb β-Decays

    NASA Astrophysics Data System (ADS)

    Rasco, B. C.; Fijałkowska, A.; Karny, M.; Rykaczewski, K. P.; Wolińska-Cichocka, M.; Goetz, K. C.; Grzywacz, R. K.; Gross, C. J.; Miernik, K.; Stracener, D.

    2015-10-01

    The NaI(Tl) based Modular Total Absorption Spectrometer (MTAS) was constructed to measure improved β-decay feeding patterns from neutron-rich nuclei. It is difficult to measure β-decay feeding intensities with high precision γ-ray measurements due to the low efficiency of high precision detectors. There are several important applications of improved measurements of β-decay feeding patterns by total absorption spectroscopy; improve understanding of elemental abundances in the universe, help with stockpile stewardship, contribute to understanding of underlying nuclear structure, and improve β-decay feeding measurements to calculate accurately the νe spectra needed to evaluate precisely reactor neutrino measurements. We present β-decay feeding results for two ``priority one'' measurements, 137Xe and 137I, and for 92Rb, which is a large individual contributor to the νe uncertainty of the reactor anomaly. In addition to β- γ decays, 137I has a β-neutron decay channel which is measurable in MTAS. We will demonstrate techniques for analyzing MTAS γ-decay data. We will also describe β and neutron spectroscopy in MTAS. This work was supported by the US DOE by Award No. DE-FG02- 96ER40978 and by US DOE, Office of Nuclear Physics.

  18. Quantitative imaging of disease signatures through radioactive decay signal conversion

    PubMed Central

    Thorek, Daniel LJ; Ogirala, Anuja; Beattie, Bradley J; Grimm, Jan

    2013-01-01

    In the era of personalized medicine there is an urgent need for in vivo techniques able to sensitively detect and quantify molecular activities. Sensitive imaging of gamma rays is widely used, but radioactive decay is a physical constant and signal is independent of biological interactions. Here we introduce a framework of novel targeted and activatable probes excited by a nuclear decay-derived signal to identify and measure molecular signatures of disease. This was accomplished utilizing Cerenkov luminescence (CL), the light produced by β-emitting radionuclides such as clinical positron emission tomography (PET) tracers. Disease markers were detected using nanoparticles to produce secondary Cerenkov-induced fluorescence. This approach reduces background signal compared to conventional fluorescence imaging. In addition to information from a PET scan, we demonstrate novel medical utility by quantitatively determining prognostically relevant enzymatic activity. This technique can be applied to monitor other markers and facilitates a shift towards activatable nuclear medicine agents. PMID:24013701

  19. Concentrations of 222Rn, 220Rn and their decay products measured in outdoor air in various rural zones (Morocco) by using solid-state nuclear track detectors and resulting radiation dose to the rural populations.

    PubMed

    Misdaq, M A; Amrane, M; Ouguidi, J

    2010-03-01

    Alpha and beta activities per unit volume of air due to radon ((222)Rn), thoron ((220)Rn) and their progenies were measured in the outdoor air at different locations in Morocco by using both CR-39 and LR-115 type II solid-state nuclear track detectors (SSNTDs). In addition, the radon concentration was continuously measured in one location by using the methods with SSNTDs and AlphaGuard counter. The influence of the geological and meteorological conditions as well as phosphate and building material dust on the radon concentration in the outdoor air of the areas studied was investigated. The committed equivalent doses due to (218)Po and (214)Po radon short-lived progeny were evaluated in different tissues of the respiratory tract of the members of the public from the inhalation of outdoor air. The annual effective dose due to radon short-lived progeny from the inhalation of outdoor air by the members of the rural population was estimated. PMID:19887516

  20. CP violation in K decays

    SciTech Connect

    Gilman, F.J.

    1989-05-01

    Recent theoretical and experimental progress on the manifestation of CP violation in K decays, and toward understanding whether CP violation originates in a phase, or phases, in the weak mixing matrix of quarks is reviewed. 23 refs., 10 figs.

  1. The Search for Proton Decay.

    ERIC Educational Resources Information Center

    Marshak, Marvin L.

    1984-01-01

    Provides the rationale for and examples of experiments designed to test the stability of protons and bound neutrons. Also considers the unification question, cosmological implications, current and future detectors, and current status of knowledge on proton decay. (JN)

  2. Questions Students Ask: Beta Decay.

    ERIC Educational Resources Information Center

    Koss, Jordan; Hartt, Kenneth

    1988-01-01

    Answers a student's question about the emission of a positron from a nucleus. Discusses the problem from the aspects of the uncertainty principle, beta decay, the Fermi Theory, and modern physics. (YP)

  3. Lorentz violation and {alpha} decay

    SciTech Connect

    Altschul, Brett

    2009-01-01

    Relating the effective Lorentz violation coefficients for composite particles to the coefficients for their constituent fields is a challenging problem. We calculate the Lorentz violation coefficients relevant to the dynamics of an {alpha} particle in terms of proton and neutron coefficients. The {alpha}-particle coefficients would lead to anisotropies in the {alpha} decays of nuclei, and because the decay process involves quantum tunneling, the effects of any Lorentz violations could be exponentially enhanced.

  4. Recent work of decay spectroscopy at RIBF

    NASA Astrophysics Data System (ADS)

    Söderström, Pär-Anders

    2014-09-01

    β- and isomer-decay spectroscopy are sensitive probes of nuclear structure, and are often the only techniques capable of providing data for exotic nuclei that are producted with very low rates. Decay properties of exotic nuclei are also essential to model astrophysical events responible for the evolution of the universe such as the rp- and r-process. The EURICA project (EUROBALL RIKEN Cluster Array) has been launched in 2012 with the goal of performing spectroscopy of very exotic nuclei. Since 2012, four experimental campaigns have been successfully completed using fragmentation of 124Xe beam and in-flight-fission of 238U beam, approaching for example the key nuclei 78Ni, 110Zr, 100Sn, 128Pd, and 138Sn. This contribution highlights the experiments performed, results obtained, and discusses the future perspective of the EURICA project. In collaboration with Shunji Nishimura, Hidetada Baba, RIKEN Nishina Center; Frank Browne, Brighton University; Pieter Doornenbal, RIKEN Nishina Center; Guillaume Gey, Universite Joseph Fourier Grenoble; Tadaaki Isobe and Giuseppe Lorusso, RIKEN Nishina Center; Daniel Lubos, Technische Universitat Munchen; Kevin Mochner, University of Cologne; Zena Patel and Simon Rice, University of Surrey; Hiroyoshi Sakurai, RIKEN Nishina Center; Laura Sinclair, University of York; Toshiyuki Sumikama, Tohoku University; Jan Taprogge, Universidad Autonoma de Madrid; Zsolt Vajta, MTA Atomki; Hiroshi Watanabe, Beihang University; Jin Wu, Peking University; and Zhengyu Xu, University of Tokyo.

  5. Chart of Nuclides from the National Nuclear Data Center (NNDC)

    DOE Data Explorer

    The Chart of Nuclides is a software product that allows users to search and plot nuclear structure and nuclear decay data interactively. The Chart of Nuclides was developed by the National Nuclear Data Center (NNDC). It provides an interface between web users and several databases containing nuclear structure, nuclear decay and some neutron-induced nuclear reaction information. Using the Chart of Nuclides, it is possible to search for nuclear level properties (energy, half-life, spin-parity), gamma-ray information (energy, intensity, multipolarity, coincidences),radiation information following nuclear decay (energy, intensity, dose), and neutron-induced reaction data from the BNL-325 book (thermal cross section and resonance integral). The information provided by the Chart of Nuclides can be seen in tables, level schemes and an interactive chart of nuclides. (From the Chart of Nuclides Description at http://www.nndc.bnl.gov/chart/help/index.jsp?product=chart)

  6. Self-Actualization Effects Of A Marathon Growth Group

    ERIC Educational Resources Information Center

    Jones, Dorothy S.; Medvene, Arnold M.

    1975-01-01

    This study examined the effects of a marathon group experience on university student's level of self-actualization two days and six weeks after the experience. Gains in self-actualization as a result of marathon group participation depended upon an individual's level of ego strength upon entering the group. (Author)

  7. The Self-Actualization of Polk Community College Students.

    ERIC Educational Resources Information Center

    Pearsall, Howard E.; Thompson, Paul V., Jr.

    This article investigates the concept of self-actualization introduced by Abraham Maslow (1954). A summary of Maslow's Needs Hierarchy, along with a description of the characteristics of the self-actualized person, is presented. An analysis of humanistic education reveals it has much to offer as a means of promoting the principles of…

  8. Depression and Self-Actualization in Gifted Adolescents.

    ERIC Educational Resources Information Center

    Berndt, David J.; And Others

    1982-01-01

    Investigated the relationship between depressive affect and self-actualization in gifted adolescents (N=248). Found that gifted students who were not self-actualizing types were more depressed; and guilt, low self-esteem, learned helplessness, and cognitive difficulty were important symptoms. Gifted adolescents tended to be more socially…

  9. 24 CFR 200.96 - Certificates of actual cost.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Endorsement Generally Applicable to Multifamily and Health Care Facility Mortgage Insurance Programs; and Continuing Eligibility Requirements for Existing Projects Cost Certification § 200.96 Certificates of actual... 24 Housing and Urban Development 2 2013-04-01 2013-04-01 false Certificates of actual cost....

  10. 24 CFR 200.96 - Certificates of actual cost.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Endorsement Generally Applicable to Multifamily and Health Care Facility Mortgage Insurance Programs; and Continuing Eligibility Requirements for Existing Projects Cost Certification § 200.96 Certificates of actual... 24 Housing and Urban Development 2 2011-04-01 2011-04-01 false Certificates of actual cost....

  11. 24 CFR 200.96 - Certificates of actual cost.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Endorsement Generally Applicable to Multifamily and Health Care Facility Mortgage Insurance Programs; and Continuing Eligibility Requirements for Existing Projects Cost Certification § 200.96 Certificates of actual... 24 Housing and Urban Development 2 2014-04-01 2014-04-01 false Certificates of actual cost....

  12. 24 CFR 200.96 - Certificates of actual cost.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Endorsement Generally Applicable to Multifamily and Health Care Facility Mortgage Insurance Programs; and Continuing Eligibility Requirements for Existing Projects Cost Certification § 200.96 Certificates of actual... 24 Housing and Urban Development 2 2012-04-01 2012-04-01 false Certificates of actual cost....

  13. 24 CFR 200.96 - Certificates of actual cost.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Endorsement Generally Applicable to Multifamily and Health Care Facility Mortgage Insurance Programs; and Continuing Eligibility Requirements for Existing Projects Cost Certification § 200.96 Certificates of actual... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Certificates of actual cost....

  14. SELF-ACTUALIZATION AND THE UTILIZATION OF TALENT.

    ERIC Educational Resources Information Center

    FRENCH, JOHN R.P.; MILLER, DANIEL R.

    THIS STUDY ATTEMPTED (1) TO DEVELOP A THEORY OF THE CAUSES AND CONSEQUENCES OF SELF-ACTUALIZATION AS RELATED TO THE UTILIZATION OF TALENT, (2) TO FIT THE THEORY TO EXISTING DATA, AND (3) TO PLAN ONE OR MORE RESEARCH PROJECTS TO TEST THE THEORY. TWO ARTICLES ON IDENTITY AND MOTIVATION AND SELF-ACTUALIZATION AND SELF-IDENTITY THEORY REPORTED THE…

  15. Facebook as a Library Tool: Perceived vs. Actual Use

    ERIC Educational Resources Information Center

    Jacobson, Terra B.

    2011-01-01

    As Facebook has come to dominate the social networking site arena, more libraries have created their own library pages on Facebook to create library awareness and to function as a marketing tool. This paper examines reported versus actual use of Facebook in libraries to identify discrepancies between intended goals and actual use. The results of a…

  16. A Study of Self-Actualization and Facilitative Communication.

    ERIC Educational Resources Information Center

    Omizo, Michael M.

    1981-01-01

    Examined the relationship between self-actualization measures and ability in facilitative communication of trainees from counseling, social work, and psychology programs to determine if differences existed between the three groups. Self-actualization indexes were significantly correlated with ability in facilitative communication. (RC)

  17. 26 CFR 1.962-3 - Treatment of actual distributions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 10 2013-04-01 2013-04-01 false Treatment of actual distributions. 1.962-3... TAX (CONTINUED) INCOME TAXES (CONTINUED) Controlled Foreign Corporations § 1.962-3 Treatment of actual... a foreign corporation. (ii) Treatment of section 962 earnings and profits under § 1.959-3....

  18. Modified OMP Algorithm for Exponentially Decaying Signals

    PubMed Central

    Kazimierczuk, Krzysztof; Kasprzak, Paweł

    2015-01-01

    A group of signal reconstruction methods, referred to as compressed sensing (CS), has recently found a variety of applications in numerous branches of science and technology. However, the condition of the applicability of standard CS algorithms (e.g., orthogonal matching pursuit, OMP), i.e., the existence of the strictly sparse representation of a signal, is rarely met. Thus, dedicated algorithms for solving particular problems have to be developed. In this paper, we introduce a modification of OMP motivated by nuclear magnetic resonance (NMR) application of CS. The algorithm is based on the fact that the NMR spectrum consists of Lorentzian peaks and matches a single Lorentzian peak in each of its iterations. Thus, we propose the name Lorentzian peak matching pursuit (LPMP). We also consider certain modification of the algorithm by introducing the allowed positions of the Lorentzian peaks' centers. Our results show that the LPMP algorithm outperforms other CS algorithms when applied to exponentially decaying signals. PMID:25609044

  19. Reionization and dark matter decay

    NASA Astrophysics Data System (ADS)

    Oldengott, Isabel M.; Boriero, Daniel; Schwarz, Dominik J.

    2016-08-01

    Cosmic reionization and dark matter decay can impact observations of the cosmic microwave sky in a similar way. A simultaneous study of both effects is required to constrain unstable dark matter from cosmic microwave background observations. We compare two reionization models with and without dark matter decay. We find that a reionization model that fits also data from quasars and star forming galaxies results in tighter constraints on the reionization optical depth τreio, but weaker constraints on the spectral index ns than the conventional parametrization. We use the Planck 2015 data to constrain the effective decay rate of dark matter to Γeff < 2.9 × 10-25/s at 95% C.L. This limit is robust and model independent. It holds for any type of decaying dark matter and it depends only weakly on the chosen parametrization of astrophysical reionization. For light dark matter particles that decay exclusively into electromagnetic components this implies a limit of Γ < 5.3 × 10-26/s at 95% C.L. Specifying the decay channels, we apply our result to the case of keV-mass sterile neutrinos as dark matter candidates and obtain constraints on their mixing angle and mass, which are comparable to the ones from the diffuse X-ray background.

  20. Reionization and dark matter decay

    NASA Astrophysics Data System (ADS)

    Oldengott, Isabel M.; Boriero, Daniel; Schwarz, Dominik J.

    2016-08-01

    Cosmic reionization and dark matter decay can impact observations of the cosmic microwave sky in a similar way. A simultaneous study of both effects is required to constrain unstable dark matter from cosmic microwave background observations. We compare two reionization models with and without dark matter decay. We find that a reionization model that fits also data from quasars and star forming galaxies results in tighter constraints on the reionization optical depth τreio, but weaker constraints on the spectral index ns than the conventional parametrization. We use the Planck 2015 data to constrain the effective decay rate of dark matter to Γeff < 2.9 × 10‑25/s at 95% C.L. This limit is robust and model independent. It holds for any type of decaying dark matter and it depends only weakly on the chosen parametrization of astrophysical reionization. For light dark matter particles that decay exclusively into electromagnetic components this implies a limit of Γ < 5.3 × 10‑26/s at 95% C.L. Specifying the decay channels, we apply our result to the case of keV-mass sterile neutrinos as dark matter candidates and obtain constraints on their mixing angle and mass, which are comparable to the ones from the diffuse X-ray background.

  1. 137 Ba Double Gamma Decay Measurement with GAMMASPHERE

    SciTech Connect

    Merchán, E.; Moran, K.; Lister, C. J.; Chowdhury, P.; McCutchan, E. A.; Greene, J. P.; Zhu, S.; Lauritsen, T.; Carpenter, M. P.; Shearman, R.

    2015-05-28

    The study of the electromagnetic moments (EM), and decay probability, provides detailed information about nuclear wave functions. The well-know properties of EM interactions are good for extracting information about the motion of nucleons. Higher order EM processes always occur, but are usually too weak to be measured. In the case of a 0+ → 0+ transitions, where a single gamma transition is forbidden, the simultaneous emission of two γ-rays has been studied. An interesting opportunity to further investigate 2-photon emission phenomena is by using a standard 137Cs source populating, via β-decay, the Jπ = 11/2- isomeric state at 662 keV in 137Ba. In this case, two photon process can have contributions from quadrupole-quadrupole or dipole-octupole multipolarities in direct competition with the high multipolarity M4 decay. Since the yield of the double gamma decay is around six orders of magnitude less than the first order transition, very good statistics are needed in order to observe the phenomena and great care must be taken to suppress the first-order decay. The Gammasphere array is ideal since its configuration allows a good coverage of the angular distribution and the Compton events can be suppressed. Nevertheless the process to understand and eliminate the Compton background is a challenge. Geant4 simulations were carried out to help understand and correct for those factors.

  2. 137 Ba Double Gamma Decay Measurement with GAMMASPHERE

    DOE PAGES

    Merchán, E.; Moran, K.; Lister, C. J.; Chowdhury, P.; McCutchan, E. A.; Greene, J. P.; Zhu, S.; Lauritsen, T.; Carpenter, M. P.; Shearman, R.

    2015-05-28

    The study of the electromagnetic moments (EM), and decay probability, provides detailed information about nuclear wave functions. The well-know properties of EM interactions are good for extracting information about the motion of nucleons. Higher order EM processes always occur, but are usually too weak to be measured. In the case of a 0+ → 0+ transitions, where a single gamma transition is forbidden, the simultaneous emission of two γ-rays has been studied. An interesting opportunity to further investigate 2-photon emission phenomena is by using a standard 137Cs source populating, via β-decay, the Jπ = 11/2- isomeric state at 662 keVmore » in 137Ba. In this case, two photon process can have contributions from quadrupole-quadrupole or dipole-octupole multipolarities in direct competition with the high multipolarity M4 decay. Since the yield of the double gamma decay is around six orders of magnitude less than the first order transition, very good statistics are needed in order to observe the phenomena and great care must be taken to suppress the first-order decay. The Gammasphere array is ideal since its configuration allows a good coverage of the angular distribution and the Compton events can be suppressed. Nevertheless the process to understand and eliminate the Compton background is a challenge. Geant4 simulations were carried out to help understand and correct for those factors.« less

  3. Beta Decay Spectroscopy of Neutron-Rich Nuclei at RIBF

    NASA Astrophysics Data System (ADS)

    Lorusso, G.; Nishimura, S.; Baba, H.; Doornenbal, P.; Isobe, T.; Söderström, P.-A.; Browne, F.; Daido, R.; Yifan, F.; Nishibata, H.; Yagi, A.; Gey, G.; Li, Z.; Wu, J.; Lubos, D.; Moschner, K.; Patel, Z.; Rice, S.; Sinclair, L.; Sumikama, T.; Taprogge, J.; Vajta, Zs.; Watanabe, H.; Xu, Z. Y.; Yoshinaga, K.

    2015-11-01

    The development of a high intensity 238U beam at the Radioactive Isotope Beam Factory (RIBF) has opened a new opportunity to explore exotic regions of the nuclear chart that were not accessible before. Along with beam development, the installation of the high efficiency γ-detector EURICA has made β-decay spectroscopy measurements of these regions possible, and a large international effort named the EURICA project has been launched to take advantage of this new opportunity.

  4. Bound muon decay spectrum in the leading logarithmic accuracy

    NASA Astrophysics Data System (ADS)

    Szafron, Robert; Czarnecki, Andrzej

    2016-09-01

    We compute the dominant, logarithmically enhanced radiative corrections to the electron spectrum in bound muon decay in the whole experimentally interesting range. The corrected spectrum fits well with the results from the TWIST Collaboration. The remaining theoretical error, dominated by the nuclear charge distribution, can be reduced in the muon-electron conversion searches by measuring the spectrum slightly below the new physics signal window.

  5. Neutrino radiative decay in N=1 supergravity theories

    NASA Astrophysics Data System (ADS)

    Degrassi, G.; Masiero, A.

    1988-02-01

    We show that the supersymmetrization of models where neutrinos acquire mass through the see-saw mechanism allows for tau neutrinos heavier than 15-20 MeV to decay radiatively in a cosmologically safe way (i.e. with a lifetime τv<=5×103s). Address after September 1, 1987: Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padua, Italy.

  6. Natural circulation decay heat removal from an SP-100, 550 kWe power system for a lunar outpost

    NASA Technical Reports Server (NTRS)

    El-Genk, Mohamed S.; Xue, Huimin

    1992-01-01

    This research investigated the decay heat removal from the SP-100 reactor core of a 550-kWe power system for a lunar outpost by natural circulation of lithium coolant. A transient model that simulates the decay heat removal loop (DHRL) of the power system was developed and used to assess the system's decay heat removal capability. The effects of the surface area of the decay heat rejection radiator, the dimensions of the decay heat exchanger (DHE) flow duct, the elevation of the DHE, and the diameter of the rise and down pipes in the DHRL on the decay heat removal capability were examined. Also, to determine the applicability of test results at earth gravity to actual system performance on the lunar surface, the effect of the gravity constant (1 g and 1/6 g) on the thermal behavior of the system after shutdown was investigated.

  7. Beta decay asymmetry in mirror nuclei: A=9

    SciTech Connect

    Tengblad, Olof; Borge, M. J. G.; Fraile, L. M.; Axelsson, L.; Jonson, B.; Nyman, G.; Markenroth, K.; Wenander, F.; Bergmann, U.; Fynbo, H. O. U.; Hornshoej, P.; Mukha, I.; Riisager, K.; Jading, Y.; Nilsson, T.; Martel, I.; Rolander, K. Wilhelmsen

    1999-11-16

    Investigations of light nuclei close to the drip lines have revealed new and intriguing features of the nuclear structure. The occurrence of halo structures in loosely bound systems has had a great impact on the nuclear physics research in the last years, as intriguing, but not yet solved, is the nature of transitions with very large beta strength. We report here on the investigation of this latter feature by an accurate measurement of the beta decay asymmetry between the mirror nuclei in the A=9 mass chain.

  8. Beta Decay Asymmetry in Mirror Nuclei: A = 9.

    SciTech Connect

    Olof Tengblad; L. Axelsson; U. Bergmann; M.J.G. Borge; L.M. Fraile; H.O.U. Fynbo; P. Hornshoj; Y. Jading; B. Jonson; T. Nilsson; G. Nyman; K. Markenroth; I. Martel; I. Mukha; K. Riisager; F. Wenander; K. Wilhelmsen Rolander

    1999-12-31

    Investigations of light nuclei close to the drip lines have revealed new and intriguing features of the nuclear structure. The occurrence of halo structures in loosely bound systems has had a great impact on the nuclear physics research in the last years, as intriguing, but not yet solved, is the nature of transitions with very large beta strength. We report here on the investigation of this latter feature by an accurate measurement of the beta decay asymmetry between the mirror nuclei in the A = 9 mass chain.

  9. Recent developments in the theory of double beta decay

    SciTech Connect

    Iachello, F.; Kotila, J.; Barea, J.

    2013-12-30

    We report results of a novel calculation of phase space factors for 2νβ{sup +}β{sup +}, 2νβ{sup +}EC, 2νECEC, 0νβ{sup +}β{sup +}, and 0νβ{sup +}EC using exact Dirac wave functions, and finite nuclear size and electron screening corrections. We present results of expected half-lives for 0νβ{sup +}β{sup +} and 0νβ{sup +}EC decays obtained by combining the calculation of phase space factors with IBM-2 nuclear matrix elements.

  10. Stability against {alpha} decay of some recently observed superheavy elements

    SciTech Connect

    Roy Chowdhury, Partha; Gangopadhyay, G.; Bhattacharyya, Abhijit

    2011-02-15

    The probability of {alpha}-particle emission for some recently observed superheavy nuclei (SHN) are investigated. The {alpha}-decay half-lives of SHN are calculated in a quantum tunneling model with density-dependent M3Y (DDM3Y) effective nuclear interaction using theoretical and measured Q{sub {alpha}} values. We determine the density distribution of {alpha} and daughter nuclei from the relativistic mean-field (RMF) theory using FSUGold force, NL3, and TM1 parameter sets. The double-folded nuclear potential is numerically calculated in a more microscopic manner using these density distributions. The estimated values of {alpha}-decay half-lives are in good agreement with the recent data. We compare our results with recently detected {alpha}-decay chains from a new element with atomic number Z=117 reported by the Joint Institute for Nuclear Research, Dubna. Finally, we determine the half-lives of superheavy elements with Z=108-120 and neutron number N=152-190 to explore the long-standing predictions of the existence of an 'island of stability' due to possible spherical proton (Z{approx}114) and neutron (N{approx}184) shell closures.

  11. Beta-decay rate and beta-delayed neutron emission probability of improved gross theory

    NASA Astrophysics Data System (ADS)

    Koura, Hiroyuki

    2014-09-01

    A theoretical study has been carried out on beta-decay rate and beta-delayed neutron emission probability. The gross theory of the beta decay is based on an idea of the sum rule of the beta-decay strength function, and has succeeded in describing beta-decay half-lives of nuclei overall nuclear mass region. The gross theory includes not only the allowed transition as the Fermi and the Gamow-Teller, but also the first-forbidden transition. In this work, some improvements are introduced as the nuclear shell correction on nuclear level densities and the nuclear deformation for nuclear strength functions, those effects were not included in the original gross theory. The shell energy and the nuclear deformation for unmeasured nuclei are adopted from the KTUY nuclear mass formula, which is based on the spherical-basis method. Considering the properties of the integrated Fermi function, we can roughly categorized energy region of excited-state of a daughter nucleus into three regions: a highly-excited energy region, which fully affect a delayed neutron probability, a middle energy region, which is estimated to contribute the decay heat, and a region neighboring the ground-state, which determines the beta-decay rate. Some results will be given in the presentation. A theoretical study has been carried out on beta-decay rate and beta-delayed neutron emission probability. The gross theory of the beta decay is based on an idea of the sum rule of the beta-decay strength function, and has succeeded in describing beta-decay half-lives of nuclei overall nuclear mass region. The gross theory includes not only the allowed transition as the Fermi and the Gamow-Teller, but also the first-forbidden transition. In this work, some improvements are introduced as the nuclear shell correction on nuclear level densities and the nuclear deformation for nuclear strength functions, those effects were not included in the original gross theory. The shell energy and the nuclear deformation for

  12. Nuclear Medicine

    MedlinePlus

    ... Parents/Teachers Resource Links for Students Glossary Nuclear Medicine What is nuclear medicine? What are radioactive tracers? ... funded researchers advancing nuclear medicine? What is nuclear medicine? Nuclear medicine is a medical specialty that uses ...

  13. Nuclear Structure Data for the Present Age

    NASA Astrophysics Data System (ADS)

    Baglin, Coral M.

    2005-05-01

    The US Nuclear Data Program maintains and provides easy and free access to several comprehensive databases that assist scientists to sift through and assess the vast quantity of published nuclear structure and decay data. These databases are an invaluable asset for nuclear-science experimentalists and theorists alike, and the recommended values provided for nuclear properties such as decay modes, level energies and lifetimes, and radiation properties can also be of great importance to specialists in other fields such as medicine, geophysics, and reactor design. The Evaluated Nuclear Structure Data File (ENSDF) contains experimental nuclear structure data for all known nuclides, evaluated by the US nuclear data program evaluators in collaboration with a number of international data groups; the Nuclear Science Reference (NSR) database provides complementary bibliographic information; the Experimental Unevaluated Nuclear Data Listing (XUNDL) exists to enable rapid access to experimental nuclear-structure data compiled from the most recent publications (primarily in high-spin physics). This paper presents an overview of the nuclear structure and decay data available through these databases, with emphasis on recent and forthcoming additions to and presentations of the available material.

  14. Indirect Methods For Nuclear Astrophysics With Radioactive Nuclear Beams

    SciTech Connect

    Trache, Livius

    2010-03-01

    For a good understanding of nucleosynthesis and energy production in stars through reliable modeling, we need nuclear data. To obtain them is the goal of nuclear physics for astrophysics, using direct and indirect measurements. In this lecture indirect methods for nuclear astrophysics are reviewed. In particular, methods applied to extract reaction rates for H-burning in stars are treated. The Coulomb dissociation is first briefly touched, for completeness. Then I go to one-nucleon transfer reactions (the ANC method), breakup reactions at intermediate energies and decay spectroscopy (beta-decay and beta-delayed proton-decay). They involve the use of radioactive nuclear beams. I chose for exemplification different experiments of our Texas A and M group, each involving a different method. The experiments were done at large energies to extract selected nuclear structure information. That is in turn used to evaluate the cross sections at low energies and the reaction rates for nuclear astrophysics. I will show the specificities of each method, their complementarities and redundancies, insisting on their peculiarities when used with radioactive beams.

  15. Fungi associated with decay in treated Douglas-fir transmission poles. [Poria carbonica and Poria placenta

    SciTech Connect

    Zabel, R.A.; Lombard, F.F.; Kenderes, A.M.

    1980-01-01

    Decay was detected by cultural methods in 190 of 952 (approximately 20%) treated Douglas-fir transmission poles installed for up to 10 years in the north-eastern United States. Preservative systems and treatments for the poles sampled were penta in petroleum oil, penta in liquefied petroluem gas, chromated copper arsenate, and ammoniacal copper arsenate. Isolations were made from various radial positions on several incrememt cores selected from the groundline zone and deep check vicinity for each pole. The decay was in early stages, often localized, and in many cases, detectable only by cultural means. The decay fungi, representing 19 identified species, were isolated primarily from untreated inner pole sections and at the groundline. Poria carbonica, a decay fungus known primarily from the western United States, and Poria placenta were the two species isolated most frequently. Six of the nineteen species were in the monocaryon nuclear condition and identified by cross matching with known monocaryon isolates and subsequent formation of clamp connections. Decay frequency in the poles generally increased with check depth. The time of occurrence and location of the decay in many poles suggests that in some cases early decay may escape preservative treatment or becomes established shortly thereafter in the storage yard. Decay may also start shortly after installation and be associated with check development into untreated wood. The data suggest that pole preparation or treatment practices that would increase preservative penetration and reduce check development would minimize decay development. (Refs. 11).

  16. Beta-decay properties of neutron-rich medium-mass nuclei

    NASA Astrophysics Data System (ADS)

    Sarriguren, Pedro

    2016-06-01

    β-decay properties of even-even and odd-A neutron-rich Ge, Se, Kr, Sr, Zr, Mo, Ru, and Pd isotopes involved in the astrophysical rapid neutron capture process are studied within a microscopic proton-neutron quasiparticle random-phase approximation. The underlying mean field is based on a self-consistent Skyrme Hartree-Fock + BCS calculation that includes deformation as a key ingredient. The isotopic evolution of the various nuclear equilibrium shapes and the corresponding charge radii are investigated in all the isotopic chains. The energy distributions of the Gamow-Teller strength, as well as the β-decay half-lives are discussed and compared with the available experimental information. It is shown that nuclear deformation plays a significant role in the description of the decay properties in this mass region. Reliable predictions of the strength distributions are essential to evaluate decay rates in astrophysical scenarios.

  17. MUON DECAY ASYMMETRIES FROM KOL YIELDS POM+M-DECAYS.

    SciTech Connect

    DIWAN, M.V.; MA, H.; TRUEMAN, T.L.

    2001-06-12

    We have examined the decay K{sub L}{sup 0} {yields} {pi}{sup 0} {mu}{sup +} {mu}{sup -} in which the branching ratio, the muon energy asymmetry and the muon decay asymmetry could be measured. In particular, we find that within the Standard Model the longitudinal polarization (PL) of the muon is proportional to the direct CP violating amplitude. On the other hand the energy asymmetry and the out-of-plane polarization (P{sub N}) depend on both indirect and direct CP violating amplitudes. Although the branching ratio is small and difficult to measure because of background, the asymmetries could be large {Omicron}(1) in the Standard Model. A combined analysis of the energy asymmetry, P{sub L} and P{sub N} could be used to separate indirect, CPV, direct CPV, and CP conserving contributions to the decay.

  18. Unsolved problems in hadronic charm decay

    SciTech Connect

    Browder, T.E.

    1989-08-01

    This paper describes several outstanding problems in the study of hadronic decays of charmed mesons where further experimental work and theoretical understanding is needed. Four topics are stressed: double Cabibbo suppressed decays (DCSD) of D/sup +/ mesons, hadronic D/sub s/ decays, weak hadronic quasi-two-body decays to pairs of vector mesons, and penguin decays of D mesons. 24 refs., 10 figs., 5 tabs.

  19. Nuclear Data Sheets for A = 200

    SciTech Connect

    Kondev, F.G.; Lalkovski, S.

    2007-07-15

    Evaluated nuclear structure and decay data for all nuclei within the A = 200 mass chain are presented. This work supersedes the earlier evaluation by M.R. Schmorak (1995Sc23), published in Nuclear Data Sheets 75, 667 (1995). The electron conversion coefficients used in the present evaluation are from 2005KiZW.

  20. Nuclear Data Sheets for A = 237

    SciTech Connect

    Basunia, M.S.

    2006-08-15

    Evaluated spectroscopic data and level schemes from radioactive decay and nuclear reaction studies are presented for all nuclei with mass number A = 237. This evaluation for A = 237 supersedes the earlier one by Y.A. Akovali (1995Ak01), published in Nuclear Data Sheets 74, 461 (1995)

  1. Nuclear Data Sheets for A = 213

    SciTech Connect

    Basunia, M.S.

    2007-03-15

    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)

  2. Nuclear Data Sheets for A = 214

    SciTech Connect

    Wu, S.-C.

    2009-03-15

    The available nuclear structure information for all nuclei with mass number A = 214 is presented. Various decay and reaction data are evaluated and compared. Adopted data, levels, spin, parity and configuration assignments are given. The present evaluation supersedes the earlier one on A = 214 by Y.A. Akovali (1995El07), published in Nuclear Data Sheets 76, 127 (1995)

  3. Nuclear data sheets update for A = 199

    SciTech Connect

    Artna-Cohen, A.

    1994-06-01

    Nuclear structure data on A = 199 have been compiled and evaluated. Results from reaction and decay studies are presented together with adopted level and transition properties. Data is presented for Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, At, and Rn. This update replaces parts of evaluation for A = 199 published in Nuclear Data Sheets 53, 331 (1988).

  4. Nuclear Data Sheets for A=143

    SciTech Connect

    Browne E.; Tuli J.; Browne,E.; Tuli.J.K.

    2012-03-01

    The evaluators present in this publication spectroscopic data and level schemes from radioactive decay and nuclear reaction studies for all nuclei with mass number A = 143. The evaluation, which includes all data received by May 2011, supersedes the 2001 evaluation by J.K. Tuli, published in Nuclear Data Sheets94, 605 (2001).

  5. Nuclear Data Sheets for A=213

    SciTech Connect

    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).

  6. Nuclear Data Sheets for A = 247

    DOE PAGES

    Nesaraja, C. D.

    2015-03-01

    Here, we present available information pertaining to the nuclear structure of all nuclei with mass number A=247. Various decay and reaction data are evaluated and compared. Adopted data, levels, spin, parity and configuration assignments are given. Moreover, when there are insufficient data, expected values from systematics of nuclear properties or/and theoretical calculations are quoted. Unexpected or discrepant experimental resultsare also noted.

  7. Nuclear Data Sheets for A = 176

    SciTech Connect

    Basunia, M.S.

    2006-04-15

    Evaluated spectroscopic data and level schemes from radioactive decay and nuclear reaction studies are presented for all nuclei with mass number A = 176. This evaluation for A = 176 supersedes the earlier one by E. Browne and Huo Junde (1998Br13), published in Nuclear Data Sheets 84, 337 (1998)

  8. [An investigation into the actual condition of the sports drink intake on children].

    PubMed

    Yamamoto, M; Amano, H; Miura, K; Nagasaka, N

    1990-01-01

    The purpose of this study was to investigate the actual condition of the sport drink intake on children. We conducted an investigation by means of questionnaires at 3 nursery schools and a day nursery in and around Hiroshima City, and using 505 answers with the comparison between 4 areas. The following results were obtained: 1) Less than 10% of the children often took sport drinks and about 70% of the children sometimes. 2) In response to the question of when taken, 40-50% of answers revealed that the drinks were taken when the children ill and 20-40% of answers were take from home. 3) In response to the question as to why children begin to take the drinks, many parents answered that they were advised by a doctor and a nurse to give their child sport drinks to prevent for dehydration, when their children were ill. This answer accounted for about 60% of the answers to this question. 4) Parents imagined that fruit drinks, carbonated beverages and beverages with lactic acid promoted tooth decay. Also the image of cariogenicity was less than 100% fruit juices, home-made juices, sport drinks, cow milks and water or tea in that order. The results suggest that parents regard sport drinks as beverages which do not promote tooth decay and give their child sport drinks frequency.

  9. Decay curve study in a standard electron capture decay

    SciTech Connect

    Nishimura, D.; Fukuda, M.; Kisamori, K.; Kuwada, Y.; Makisaka, K.; Matsumiya, R.; Matsuta, K.; Mihara, M.; Takagi, A.; Yokoyama, R.; Izumikawa, T.; Ohtsubo, T.; Suzuki, T.; Yamaguchi, T.

    2010-05-12

    We have searched for a time-modulated decay in a standard electron capture experiment for {sup 140}Pr, in order to confirm a report from GSI, where an oscillatory decay has been observed for hydrogen-like {sup 140}Pr and {sup 142}Pm ions in the cooler storage ring. {sup 140}Pr has been produced with the {sup 140}Ce(p, n) reaction by a pulsed proton beam accelerated from the Van de Graaff accelerator at Osaka University. Resultant time dependence of the K{sub a}lpha and K{sub b}eta X-ray intensities from the daughter shows no oscillatory behavior.

  10. 10 CFR 35.2092 - Records of decay-in-storage.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Records of decay-in-storage. 35.2092 Section 35.2092 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Records § 35.2092 Records of decay-in-storage. A licensee shall maintain records of the disposal of licensed materials, as required by § 35.92, for 3 years. The record must include...

  11. 10 CFR 35.2092 - Records of decay-in-storage.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Records of decay-in-storage. 35.2092 Section 35.2092 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Records § 35.2092 Records of decay-in-storage. A licensee shall maintain records of the disposal of licensed materials, as required by § 35.92, for 3 years. The record must include...

  12. Fission Product Decay Heat Calculations for Neutron Fission of 232Th

    NASA Astrophysics Data System (ADS)

    Son, P. N.; Hai, N. X.

    2016-06-01

    Precise information on the decay heat from fission products following times after a fission reaction is necessary for safety designs and operations of nuclear-power reactors, fuel storage, transport flasks, and for spent fuel management and processing. In this study, the timing distributions of fission products' concentrations and their integrated decay heat as function of time following a fast neutron fission reaction of 232Th were exactly calculated by the numerical method with using the DHP code.

  13. Superpower nuclear minimalism

    SciTech Connect

    Graben, E.K.

    1992-01-01

    During the Cold War, the United States and the Soviet Union competed in building weapons -- now it seems like America and Russia are competing to get rid of them the fastest. The lengthy process of formal arms control has been replaced by exchanges of unilateral force reductions and proposals for reciprocal reductions not necessarily codified by treaty. Should superpower nuclear strategies change along with force postures President Bush has yet to make a formal pronouncement on post-Cold War American nuclear strategy, and it is uncertain if the Soviet/Russian doctrine of reasonable sufficiency formulated in the Gorbachev era actually heralds a change in strategy. Some of the provisions in the most recent round of unilateral proposals put forth by Presidents Bush and Yeltsin in January 1992 are compatible with a change in strategy. Whether such a change has actually occurred remains to be seen. With the end of the Cold War and the breakup of the Soviet Union, the strategic environment has fundamentally changed, so it would seem logical to reexamine strategy as well. There are two main schools of nuclear strategic thought: a maximalist school, mutual assured destruction (MAD) which emphasizes counterforce superiority and nuclear war- fighting capability, and a MAD-plus school, which emphasizes survivability of an assured destruction capability along with the ability to deliver small, limited nuclear attacks in the event that conflict occurs. The MAD-plus strategy is based on an attempt to conventionalize nuclear weapons which is unrealistic.

  14. Status and prospects of investigations into the collinear cluster decay of heavy nuclei

    SciTech Connect

    Pyatkov, Yu. V.; Kamanin, D. V.; Alexandrov, A. A.; Alexandrova, I. A.; Mkaza, N.; Zhuchko, V. E.; Kondratyev, N. A.; Kuznetsova, E. A. Mishinsky, G. V.; Malaza, V.; Strekalovsky, A. O.; Strekalovsky, O. V.

    2014-12-15

    Basic experimental results confirming the existence a new cluster-decay type called collinear cluster tripartition (CCT) are presented. Decays of this type manifest themselves, in particular, as a two-dimensional region of a locally enhanced yield of fragments (bump) that corresponds to specific missing-mass values in the mass-mass distribution of fission fragments. One of the decay modes that contribute to the bump can be treated as a cluster-decay type that is new in relation to the well-known heavy-ion or lead radioactivity. The conclusions drawn from an analysis of correlation mass distributions are confirmed by the results obtained from neutron-gated data, measurements of the nuclear charge for CCT events, and the direct detection of new-decay products.

  15. Radiative decay of neutron-unbound intruder states in 19O

    NASA Astrophysics Data System (ADS)

    Dungan, R.; Tabor, S. L.; Tripathi, Vandana; Volya, A.; Kravvaris, K.; Abromeit, B.; Caussyn, D. D.; Morrow, S.; Parker, J. J.; Tai, P.-L.; VonMoss, J. M.

    2016-02-01

    The 9Be(14C, α γ ) reaction at EL a b=30 and 35 MeV was used to study excited states of 19O. The Florida State University (FSU) γ detector array was used to detect γ radiation in coincidence with charged particles detected and identified with a silicon Δ E -E particle telescope. γ decays have been observed for the first time from six states ranging from 368 to 2147 keV above the neutron separation energy (Sn=3962 keV) in 19O. The γ -decaying states are interspersed among states previously observed to decay by neutron emission. The ability of electromagnetic decay to compete successfully with neutron decay is explained in terms of neutron angular momentum barriers and small spectroscopic factors implying higher spin and complex structure for these intruder states. These results illustrate the need for complementary experimental approaches to best illuminate the complete nuclear structure.

  16. Theory of neutrinoless double-beta decay

    NASA Astrophysics Data System (ADS)

    Vergados, J. D.; Ejiri, H.; Šimkovic, F.

    2012-10-01

    Neutrinoless double-beta decay, which is a very old and yet elusive process, is reviewed. Its observation will signal that the lepton number is not conserved and that 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 must be overcome involving particle, nuclear and experimental physics. Nuclear physics is important for extracting 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 which have recently been developed, and which give confidence that the required nuclear matrix elements can be reliably calculated employing different methods: (a) the various versions of the quasiparticle random phase approximations, (b) the interacting boson model, (c) the energy density functional method and (d) the large basis interacting shell model. It is encouraging that, for the light neutrino-mass term at least, these vastly different approaches now give comparable results. From an experimental point of view it is challenging, since the life times are long and one has to fight against formidable backgrounds. One needs large isotopically enriched sources and detectors with high-energy resolution, low thresholds and very low background. If a signal is found, it will be a tremendous accomplishment. The real task then, of course, will be the extraction of the neutrino mass from the observations. This is not trivial, since current particle models predict the presence of many mechanisms other than the neutrino mass, which may contribute to or even dominate this process. In particular, we will consider the following processes: The neutrino induced, but neutrino-mass independent contribution. Heavy left and/or right-handed neutrino-mass contributions. Intermediate scalars (doubly charged, etc

  17. Two-step mechanisms of two-proton decays of nuclei

    NASA Astrophysics Data System (ADS)

    Kadmensky, S. G.; Ivankov, Yu. V.

    2014-08-01

    A formalism for describing two-step two-proton decays of nuclei is developed on the basis of the multiparticle theory of deep-subbarrier one-proton decays of nuclei that employs integral expression for the decay widths in question. This formalism relies on the idea that the interaction between the emitted protons has but a slight effect on the widths with respect to the two-proton decays being considered. It is shown that such a decay is naturally broken down into the sequential one-proton decays of an ( A, Z) parent nucleus and an ( A - 1, Z - 1) intermediate nucleus, these decays being related by the Green's function G( A - 1, Z - 1) that describes the intermediate nucleus with allowance for its real and virtual states, which give rise to, respectively, the sequential and the virtual two-step two-proton decay of the parent nucleus. It is also shown that the widths with respect to sequential two-step two-proton decays coincide with the analogous widths constructed within the R-matrix theory of nuclear reactions leading to the production of unstable particles and with their counterparts obtained with the aid of solving the set of kinetic equations for the chain of nuclei undergoing radioactive decays. It is found that the widths with respect to virtual two-step two-proton decays are close in structure to the widths constructed for the simultaneous two-proton decays of nuclei by using integrated formulas within a simplified model of the method of three-particle hyperspherical polynomials.

  18. Nuclear Data Sheets for A = 54

    SciTech Connect

    Dong, Yang; Junde, Huo

    2014-09-15

    The 2005 evaluation for A=54 (2006Hu08) has been updated. Detailed experimental nuclear structure data and decay data for all nuclei with mass chain A=54 are presented in this current evaluation. The new data and information are given in following datasets: {sup 54}Ca: {sup 9}Be({sup 76}Ge, X) and Be({sup 55}Sc, p), ({sup 56}Ti, 2p) {sup 54}Sc: {sup 54}Ca β{sup −} decay and {sup 54}Sc IT decay {sup 54}Ti: {sup 54}Sc β{sup −} decay {sup 54}Cr: {sup 54}Mn ε decay, {sup 56}Fe(μ, nupng), and {sup 238}U({sup 64}Ni, Xγ) {sup 54}Mn: {sup 51}V({sup 20}Ne, Xγ), {sup 55}Mn(p, pn), and {sup 56}Fe(μ, nu2ng) {sup 54}Fe: {sup 58}Ni α decay, {sup 9}Be({sup 55}Co, Xγ), {sup 54}Fe(e, e'), {sup 54}Fe(p, p'), and Coulomb Excitation {sup 54}Co: {sup 54}Ni ε decay, {sup 55}Cu εp decay, {sup 28}Si({sup 32}S, αpnγ), {sup 54}Fe(p,n), and {sup 54}Fe({sup 3}He, t) {sup 54}Ni: {sup 54}Ni IT decay, {sup 55}Zn εp decay, {sup 9}Be({sup 55}Ni, Xγ), and {sup 24}Mg({sup 32}S, Xγ) {sup 54}Zn: Ni({sup 58}Ni, X)

  19. Nuclear-chemical methods in a hard tooth tissue abrasion study

    NASA Astrophysics Data System (ADS)

    Gosman, A.; Spěváček, V.; Koníček, J.; Vopálka, D.; Houŝová, D.; Doležalová, L.

    1999-01-01

    The advanced method consists in implantation—labelling of the thin surface layers of the solid objects, e.g. hard tooth tissue, by atoms of suitable natural or artificial radionuclides. Nuclides from the uranium series were implanted into the surface by using nuclear recoil effect at alpha decay of 226Ra to 222Rn, alpha decay of 222Rn to RaA, alpha decay of RaA to RaB (beta-emitter) and further alpha or beta emitters. With regard to chosen alpha detection and to the half—lives of the radionuclides, there was actually measured the activity of 222Rn, RaA and RaC’ in the thin surface layer. This was followed by the laboratory simulation of the abrasion in the system of “toothbrush—various suspensions of the tooth-pastes—hard tooth tissue (or material standard—ivory)” in specially designed device—the dentoabrasionmeter. The activities of the tissue surface measured before and after abrasion were used for calculations of the relative drop of the surface activity. On this basis the influence of various tooth-pastes containing various abrasive substances was determined.

  20. The decay constant of 87Rb

    NASA Astrophysics Data System (ADS)

    Rotenberg, E.; Davis, D. W.; Amelin, Y.

    2009-05-01

    Despite dozens of measurements of the decay constant of 87Rb (λ87), uncertainty surrounding the value remains. Mounting evidence [e.g. 1,2,3] suggests that the actual value is 1-2% lower than the conventional value of 1.42 × 10-11a-1 [4]. Increased precision and accuracy are crucial if meaningful comparisons are to be made between Rb-Sr and U-Pb ages. We have been working on measuring the decay constant by the accumulation of radiogenic 87Sr (87Sr*) in a RbClO4 salt. Our original measurements by this method had large errors [5,6] and tended to agree with the conventional value. Because the samples contained very little common Sr, it was impossible to properly correct for instrumental fractionation, with the result that both precision and accuracy were compromised. Furthermore, the concentration of the 84Sr spike was not determined reliably, which likely affected the accuracy. In order to overcome this, a new 84-86Sr double-spike was prepared, and the experiment was repeated. The spike was calibrated against three different Sr reference solutions. Two were prepared from Sr metal and the third from SrCl2. The isotopic abundance ratios of the 84-86Sr double-spike are: 84/86 = 0.93252, 87/86 = 0.01033, and 88/86 = 0.02240. The concentration was determined to be 832.95 ± 0.26 ng Sr/g solution (MSWD = 2.5). Seventeen measurements of the decay-constant were made by measuring 87Sr* ingrowth in a RbClO4 salt over approximately 32 years. 87Sr* ranges from 125 - 616 pg. The two highest points are eliminated: one due to high procedure blank and the second due to abnormal fractionation behaviour. A weighted average of the remaining fifteen measurements yields a decay constant of 1.3981 × 10-11a-11 ± 0.0009 (0.062%; and a high MSWD = 106. The 2σ standard deviation is 0.004). The data scatter outside of their analytical errors. Recent geological calibrations [1,2] and a carefully controlled decay counting measurement [3] yield λ87 values from 1.395 ± 0.006 to 1.398 ± 0

  1. Observation of Doppler broadening in β -delayed proton- γ decay

    DOE PAGES

    Schwartz, S. B.; Wrede, C.; Bennett, M. B.; Liddick, S. N.; Pérez-Loureiro, D.; Bowe, A.; Chen, A. A.; Chipps, K. A.; Cooper, N.; Irvine, D.; et al

    2015-09-14

    Background: The Doppler broadening of gamma-ray peaks is due to nuclear recoil from beta-delayed nucleon emission can be used to measure the energies of the nucleons. This method has never been tested using beta-delayed proton emission or applied to a recoil heavier than A = 10. Purpose: To test and apply this Doppler broadening method using gamma-ray peaks from the P-26(beta p gamma)Al-25 decay sequence. Methods: A fast beam of P-26 was implanted into a planar Ge detector, which was used as a P-26 beta-decay trigger. The SeGA array of high-purity Ge detectors was used to detect gamma rays frommore » the P-26(beta p gamma)Al-25 decay sequence. Results: Radiative Doppler broadening in beta-delayed proton-gamma decay was observed for the first time. Moreover, the Doppler broadening analysis method was verified using the 1613-keV gamma-ray line for which the proton energies were previously known. The 1776-keV gamma ray de-exciting the 2720 keV Al-25 level was observed in P-26(beta p gamma)Al-25 decay for the first time and used to determine that the center-of-mass energy of the proton emission feeding the 2720-keV level is 5.1 +/- 1.0 (stat.) +/- 0.6 (syst.) MeV, corresponding to a Si-26 excitation energy of 13.3 +/- 1.0 (stat.) +/- 0.6 (syst.) MeV for the proton-emitting level. Conclusions: Finally, the Doppler broadening method has been demonstrated to provide practical measurements of the energies for beta-delayed nucleon emissions populating excited states of nuclear recoils at least as heavy as A = 25.« less

  2. An Accelerated Radioactive Decay (ARD) Model for Type Ia Supernovae

    NASA Astrophysics Data System (ADS)

    Rust, Bert W.; Leventhal, Marvin

    2016-01-01

    In 1975, Leventhal and McCall [Nature, 255, 690-692] presented a radioactive decay model 56N i --> 56Co --> 56Fe for the post-peak luminosity decay of Type I supernovae light curves, in which the two decay rates are both accelerated by a common factor. In 1976, Rust, Leventhal and McCall [Nature, 262, 118-120] used sums of exponentials fitting to confirm the acceleration hypothesis, but their result was nevertheless rejected by the astronomical community. Here, we model Type Ia light curves with a system of ODEs (describing the nuclear decays) forced by a Ni-deposition pulse modelled by a 3-parameter Weibull pdf, with all of this occuring in the center of a pre-existing, optically thick, spherical shell which thermalizes the emitted gamma rays. Fitting this model to observed light curves routinely gives fits which account for 99.9+% of the total variance in the observed record. The accelerated decay rates are so stable, for such a long time, that they must occur in an almost unchanging environment -- not it a turbulent expanding atmosphere. The amplitude of the Ni-deposition pulse indicates that its source is the fusion of hydrogen. Carbon and oxygen could not supply the large energy/nucleon that is observed. The secondary peak in the infrared light curve can be easily modelled as a light echo from dust in the back side of the pre-existing shell, and the separation between the peaks indicates a radius of ≈15 light days for the shell. The long-term stability of the acceleration suggests that it is a kinematic effect arising because the nuclear reactions occur either on the surface of a very rapidly rotating condensed object, or in a very tight orbit around such an object, like the fusion pulse in a tokomak reactor.

  3. Heavy quark spectroscopy and decay

    SciTech Connect

    Schindler, R.H.

    1987-01-01

    The understanding of q anti q systems containing heavy, charmed, and bottom quarks has progressed rapidly in recent years, through steady improvements in experimental techniques for production and detection of their decays. These lectures are meant to be an experimentalist's review of the subject. In the first of two lectures, the existing data on the spectroscopy of the bound c anti c and b anti b systems will be discussed. Emphasis is placed on comparisons with the theoretical models. The second lecture covers the rapidly changing subject of the decays of heavy mesons (c anti q and b anti q), and their excited states. In combination, the spectroscopy and decays of heavy quarks are shown to provide interesting insights into both the strong and electroweak interactions of the heavy quarks. 103 refs., 39 figs.

  4. Decay of capillary wave turbulence.

    PubMed

    Deike, Luc; Berhanu, Michael; Falcon, Eric

    2012-06-01

    We report on the observation of freely decaying capillary wave turbulence on the surface of a fluid. The capillary wave turbulence spectrum decay is found to be self-similar in time with the same power law exponent as the one found in the stationary regime, in agreement with weak turbulence predictions. The amplitude of all Fourier modes are found to decrease exponentially with time at the same damping rate. The longest wavelengths involved in the system are shown to be damped by a viscous surface boundary layer. These long waves play the role of an energy source during the decay that sustains nonlinear interactions to keep capillary waves in a wave turbulent state.

  5. Safety of patients--actual problem of modern medicine (review).

    PubMed

    Tsintsadze, Neriman; Samnidze, L; Beridze, T; Tsintsadze, M; Tsintsadze, Nino

    2011-09-01

    Safety of patients is actual problem of up-to-date medicine. The current successful treatment of various sicknesses is achieved by implementation in clinical practice such medical preparations (medications), which are characterized with the high therapeutic activity, low toxicity and prolonged effects. In spite of evidence of the pharmacotherapeutical advances, the frequency of complications after medication has grown - that is why the safety of patients is the acute actual problem of medicine and ecological state of human population today. PMID:22156680

  6. Measurement of fission products β decay properties using a total absorption spectrometer

    NASA Astrophysics Data System (ADS)

    Zakari-Issoufou, A.-A.; Porta, A.; Fallot, M.; Algora, A.; Tain, J. L.; Valencia, E.; Rice, S.; Agramunt, J.; Äystö, J.; Bowry, M.; Bui, V. M.; Caballero-Folch, R.; Cano-Ott, D.; Eloma, V.; Estévez, E.; Farrelly, G. F.; Garcia, A.; Gelletly, W.; Gomez-Hornillos, M. B.; Gorlychev, V.; Hakala, J.; Jokinen, A.; Jordan, M. D.; Kankainen, A.; Kondev, F. G.; Martinez, T.; Mendoza, E.; Molina, F.; Moore, I.; Perez, A.; Podolyak, Zs.; Penttilä, H.; Regan, P. H.; Rissanen, J.; Rubio, B.; Weber, C.

    2013-12-01

    In a nuclear reactor, the β decay of fission fragments is at the origin of decay heat and antineutrino flux. These quantities are not well known while they are very important for reactor safety and for our understanding of neutrino physics. One reason for the discrepancies observed in the estimation of the decay heat and antineutrinos flux coming from reactors could be linked with the Pandemonium effect. New measurements have been performed at the JYFL facility of Jyväskylä with a Total Absorption Spectrometer (TAS) in order to circumvent this effect. An overview of the TAS technique and first results from the 2009 measurement campaign will be presented.

  7. 29Si NMR spin-echo decay in YbRh2Si2

    NASA Astrophysics Data System (ADS)

    Kambe, S.; Sakai, H.; Tokunaga, Y.; Hattori, T.; Lapertot, G.; Matsuda, T. D.; Knebel, G.; Flouquet, J.; Walstedt, R. E.

    2016-02-01

    29Si nuclear magnetic resonance (NMR) has been measured in a 29Si-enriched single crystal sample of YbRh2Si2. The spin-echo decay for applied field H ∥, ⊥ the c-axes has been measured at 100 K. A clear spin-echo decay oscillation is observed for both cases, possibly reflecting the Ruderman-Kittel (RK) interaction. Since the observed oscillation frequency depends on the direction of applied magnetic field, anisotropic RK coupling and pseudo-dipolar (PD) interactions may not be negligible in this compound. The origin of spin-echo decay oscillations is discussed.

  8. Free-decay time-domain modal identification for large space structures

    NASA Technical Reports Server (NTRS)

    Kim, Hyoung M.; Vanhorn, David A.; Doiron, Harold H.

    1992-01-01

    Concept definition studies for the Modal Identification Experiment (MIE), a proposed space flight experiment for the Space Station Freedom (SSF), have demonstrated advantages and compatibility of free-decay time-domain modal identification techniques with the on-orbit operational constraints of large space structures. Since practical experience with modal identification using actual free-decay responses of large space structures is very limited, several numerical and test data reduction studies were conducted. Major issues and solutions were addressed, including closely-spaced modes, wide frequency range of interest, data acquisition errors, sampling delay, excitation limitations, nonlinearities, and unknown disturbances during free-decay data acquisition. The data processing strategies developed in these studies were applied to numerical simulations of the MIE, test data from a deployable truss, and launch vehicle flight data. Results of these studies indicate free-decay time-domain modal identification methods can provide accurate modal parameters necessary to characterize the structural dynamics of large space structures.

  9. Nuclear physics and heavy element research at LLNL

    SciTech Connect

    Stoyer, M A; Ahle, L E; Becker, J A; Bernstein, L A; Bleuel, D L; Burke, J T; Dashdorj, D; Henderson, R A; Hurst, A M; Kenneally, J M; Lesher, S R; Moody, K J; Nelson, S L; Norman, E B; Pedretti, M; Scielzo, N D; Shaughnessy, D A; Sheets, S A; Stoeffl, W; Stoyer, N J; Wiedeking, M; Wilk, P A; Wu, C Y

    2009-05-11

    This paper highlights some of the current basic nuclear physics research at Lawrence Livermore National Laboratory (LLNL). The work at LLNL concentrates on investigating nuclei at the extremes. The Experimental Nuclear Physics Group performs research to improve our understanding of nuclei, nuclear reactions, nuclear decay processes and nuclear astrophysics; an expertise utilized for important laboratory national security programs and for world-class peer-reviewed basic research.

  10. β decay of Na32

    NASA Astrophysics Data System (ADS)

    Mattoon, C. M.; Sarazin, F.; Hackman, G.; Cunningham, E. S.; Austin, R. A. E.; Ball, G. C.; Chakrawarthy, R. S.; Finlay, P.; Garrett, P. E.; Grinyer, G. F.; Hyland, B.; Koopmans, K. A.; Leslie, J. R.; Phillips, A. A.; Schumaker, M. A.; Scraggs, H. C.; Schwarzenberg, J.; Smith, M. B.; Svensson, C. E.; Waddington, J. C.; Walker, P. M.; Washbrook, B.; Zganjar, E.

    2007-01-01

    The β-decay of Na32 has been studied using β-γ coincidences. New transitions and levels are tentatively placed in the level scheme of Mg32 from an analysis of γ-γ and β-γ-γ coincidences. The observation of the indirect feeding of the 2321 keV state in Mg32 removes some restrictions previously placed on the spin assignment for this state. No evidence of a state at 2117 keV in Mg32 is found. Previously unobserved weak transitions up to 5.4 MeV were recorded but could not be placed in the decay scheme of Na32.

  11. Laser-Assisted Muon Decay

    SciTech Connect

    Liu Aihua; Li Shumin; Berakdar, Jamal

    2007-06-22

    We show theoretically that the muon lifetime can be changed dramatically by embedding the decaying muon in a strong linearly polarized laser field. Evaluating the S-matrix elements taking all electronic multiphoton processes into account we find that a CO{sub 2} laser with an electric field amplitude of 10{sup 6} V cm{sup -1} results in an order of magnitude shorter lifetime of the muon. We also analyze the dependencies of the decay rate on the laser frequency and intensity.

  12. Resonant Auger decay driving intermolecular Coulombic decay in molecular dimers

    NASA Astrophysics Data System (ADS)

    Trinter, F.; Schöffler, M. S.; Kim, H.-K.; Sturm, F. P.; Cole, K.; Neumann, N.; Vredenborg, A.; Williams, J.; Bocharova, I.; Guillemin, R.; Simon, M.; Belkacem, A.; Landers, A. L.; Weber, Th.; Schmidt-Böcking, H.; Dörner, R.; Jahnke, T.

    2014-01-01

    In 1997, it was predicted that an electronically excited atom or molecule placed in a loosely bound chemical system (such as a hydrogen-bonded or van-der-Waals-bonded cluster) could efficiently decay by transferring its excess energy to a neighbouring species that would then emit a low-energy electron. This intermolecular Coulombic decay (ICD) process has since been shown to be a common phenomenon, raising questions about its role in DNA damage induced by ionizing radiation, in which low-energy electrons are known to play an important part. It was recently suggested that ICD can be triggered efficiently and site-selectively by resonantly core-exciting a target atom, which then transforms through Auger decay into an ionic species with sufficiently high excitation energy to permit ICD to occur. Here we show experimentally that resonant Auger decay can indeed trigger ICD in dimers of both molecular nitrogen and carbon monoxide. By using ion and electron momentum spectroscopy to measure simultaneously the charged species created in the resonant-Auger-driven ICD cascade, we find that ICD occurs in less time than the 20femtoseconds it would take for individual molecules to undergo dissociation. Our experimental confirmation of this process and its efficiency may trigger renewed efforts to develop resonant X-ray excitation schemes for more localized and targeted cancer radiation therapy.

  13. Single and Double Beta-Decay Q Values among the Triplet 96Zr, 96Nb, and 96Mo

    NASA Astrophysics Data System (ADS)

    Alanssari, M.; Frekers, D.; Eronen, T.; Canete, L.; Dilling, J.; Haaranen, M.; Hakala, J.; Holl, M.; Ješkovský, M.; Jokinen, A.; Kankainen, A.; Koponen, J.; Mayer, A. J.; Moore, I. D.; Nesterenko, D. A.; Pohjalainen, I.; Povinec, P.; Reinikainen, J.; Rinta-Antila, S.; Srivastava, P. C.; Suhonen, J.; Thompson, R. I.; Voss, A.; Wieser, M. E.

    2016-02-01

    The atomic mass relations among the mass triplet 96Zr, 96Nb, and 96Mo have been determined by means of high-precision mass measurements using the JYFLTRAP mass spectrometer at the IGISOL facility of the University of Jyväskylä. We report Q values for the 96Zr single and double β decays to 96Nb and 96decay to 96Mo, which are Qβ(96Zr)=163.96 (13 ) , Qβ β(96Zr)=3356.097 (86 ) , and Qβ(96Nb)=3192.05 (16 ) keV . Of special importance is the 96Zr single β -decay Q value, which has never been determined directly. The single β decay, whose main branch is fourfold unique forbidden, is an alternative decay path to the 96Zr β β decay, and its observation can provide one of the most direct tests of the neutrinoless β β -decay nuclear-matrix-element calculations, as these can be simultaneously performed for both decay paths with no further assumptions. The theoretical single β -decay rate has been re-evaluated using a shell-model approach, which indicates a 96Zr single β -decay lifetime within reach of an experimental verification. The uniqueness of the decay also makes such an experiment interesting for an investigation into the origin of the quenching of the axial-vector coupling constant gA.

  14. The Fourier Transform in Chemistry. Part 1. Nuclear Magnetic Resonance: Introduction.

    ERIC Educational Resources Information Center

    King, Roy W.; Williams, Kathryn R.

    1989-01-01

    Using fourier transformation methods in nuclear magnetic resonance has made possible increased sensitivity in chemical analysis. This article describes these methods as they relate to magnetization, the RF magnetic field, nuclear relaxation, the RF pulse, and free induction decay. (CW)

  15. The Future of Spacecraft Nuclear Propulsion

    NASA Astrophysics Data System (ADS)

    Jansen, F.

    2014-06-01

    This paper summarizes the advantages of space nuclear power and propulsion systems. It describes the actual status of international power level dependent spacecraft nuclear propulsion missions, especially the high power EU-Russian MEGAHIT study including the Russian Megawatt-Class Nuclear Power Propulsion System, the NASA GRC project and the low and medium power EU DiPoP study. Space nuclear propulsion based mission scenarios of these studies are sketched as well.

  16. Evaluated Nuclear Data

    SciTech Connect

    Oblozinsky, P.; Oblozinsky,P.; Herman,M.; Mughabghab,S.F.

    2010-10-01

    This chapter describes the current status of evaluated nuclear data for nuclear technology applications. We start with evaluation procedures for neutron-induced reactions focusing on incident energies from the thermal energy up to 20 MeV, though higher energies are also mentioned. This is followed by examining the status of evaluated neutron data for actinides that play dominant role in most of the applications, followed by coolants/moderators, structural materials and fission products. We then discuss neutron covariance data that characterize uncertainties and correlations. We explain how modern nuclear evaluated data libraries are validated against an extensive set of integral benchmark experiments. Afterwards, we briefly examine other data of importance for nuclear technology, including fission yields, thermal neutron scattering and decay data. A description of three major evaluated nuclear data libraries is provided, including the latest version of the US library ENDF/B-VII.0, European JEFF-3.1 and Japanese JENDL-3.3. A brief introduction is made to current web retrieval systems that allow easy access to a vast amount of up-to-date evaluated nuclear data for nuclear technology applications.

  17. Perspectives of Nuclear Physics

    NASA Astrophysics Data System (ADS)

    Faessler, Amand

    2003-04-01

    The organizers of this meeting have asked me to present perspectives of nuclear physics. This means to identify the areas where nuclear physics will be expanding in the next future. In six chapters a short overview of these areas will be given, where I expect that nuclear physics will develop quite fast: (1) Quantum Chromodynamics and effective field theories in the confinement region. (2) Nuclear structure at the limits. (3) High energy heavy ion collisions. (4) Nuclear astrophysics. (5) Neutrino physics. (6) Test of physics beyond the standard model by rare processes. After a survey over these six points I will pick out a few topics where I will go more in details. There is no time to give for all six points detailed examples. I shall discuss the following examples of the six topics mentionned above: (1) The perturbative chiral quark model and the nucleon Σ-term. (2) VAMPIR (Variation After Mean field Projection In Realistic model spaces and with realistic forces) as an example of the nuclear structure renaissance. (3) Measurement of important astrophysical nuclear reactions in the Gamow peak. (4) The solar neutrino problem. As examples for testing new physics beyond the standard model by rare processes I had prepared to speak about the measurement of the electric neutron dipole moment and of the neutrinoless double beta decay. But the time is limited and so I have to skip these points, although they are extremely interesting.

  18. Nuclear Futures Analysis and Scenario Building

    SciTech Connect

    Arthur, E.D.; Beller, D.; Canavan, G.H.; Krakowski, R.A.; Peterson, P.; Wagner, R.L.

    1999-07-09

    This LDRD project created and used advanced analysis capabilities to postulate scenarios and identify issues, externalities, and technologies associated with future ''things nuclear''. ''Things nuclear'' include areas pertaining to nuclear weapons, nuclear materials, and nuclear energy, examined in the context of future domestic and international environments. Analysis tools development included adaptation and expansion of energy, environmental, and economics (E3) models to incorporate a robust description of the nuclear fuel cycle (both current and future technology pathways), creation of a beginning proliferation risk model (coupled to the (E3) model), and extension of traditional first strike stability models to conditions expected to exist in the future (smaller force sizes, multipolar engagement environments, inclusion of actual and latent nuclear weapons (capability)). Accomplishments include scenario development for regional and global nuclear energy, the creation of a beginning nuclear architecture designed to improve the proliferation resistance and environmental performance of the nuclear fuel cycle, and numerous results for future nuclear weapons scenarios.

  19. Nuclear exoticism

    NASA Astrophysics Data System (ADS)

    Penionzhkevich, Yu. E.

    2016-07-01

    Extreme states of nuclearmatter (such that feature high spins, large deformations, high density and temperature, or a large excess of neutrons and protons) play an important role in studying fundamental properties of nuclei and are helpful in solving the problem of constructing the equation of state for nuclear matter. The synthesis of neutron-rich nuclei near the nucleon drip lines and investigation of their properties permit drawing conclusions about the positions of these boundaries and deducing information about unusual states of such nuclei and about their decays. At the present time, experimental investigations along these lines can only be performed via the cooperation of leading research centers that possess powerful heavy-ion accelerators, such as the Large Hadron Collider (LHC) at CERN and the heavy-ion cyclotrons at the Joint Institute for Nuclear Research (JINR, Dubna), where respective experiments are being conducted by physicists from about 20 JINR member countries. The present article gives a survey of the most recent results in the realms of super neutron-rich nuclei. Implications of the change in the structure of such nuclei near the nucleon drip lines are discussed. Information about the results obtained by measuring the masses (binding energies) of exotic nuclei, the nucleon-distribution radii (neutron halo) and momentum distributions in them, and their deformations and quantum properties is presented. It is shown that the properties of nuclei lying near the stability boundaries differ strongly from the properties of other nuclei. The problem of the stability of nuclei that is associated with the magic numbers of 20 and 28 is discussed along with the effect of new magic numbers.

  20. Scientific Solutions to Nuclear Waste Environmental Challenges

    SciTech Connect

    Johnson, Bradley R.

    2014-01-30

    of time it takes for one-half of the material to undergo radioactive decay.) In general, the ideal material would need to be durable for approximately 10 half-lives to allow the activity to decay to negligible levels. However, the potential health effects of each radionuclide vary depending on what type of radiation is emitted, the energy of that emission, and the susceptibility for the human body to accumulate and concentrate that particular element. Consequently, actual standards tend to be based on limiting the dose (energy deposited per unit mass) that is introduced into the environment. The Environmental Protection Agency (EPA) has the responsibility to establish standards for nuclear waste disposal to protect the health and safety of the public. For example, the Energy Policy Act of 1992 directed the EPA to establish radiation protection standards for the Yucca Mountain geologic repository for nuclear wastes. The standards for Yucca Mountain were promulgated in 2008, and limit the dose to 15 millirem per year for the first 10,000 years, and 100 milirem per year between 10,000 years and 1 million years (40 CFR Part 197; http://www.epa.gov/radiation/yucca/2008factsheet.html). So, the challenge is two-fold: (1) develop a material (a waste form) that is capable of immobilizing the waste over geologic time scales, and (2) develop a process to convert the radioactive sludge in the tanks into this durable waste form material. Glass: Hard, durable, inert, and with infinite chemical versatility Molten glass is a powerful solvent liquid, which can be designed to dissolve almost anything. When solidified, it can be one of the most chemically inert substances known to man. Nature's most famous analogue to glass is obsidian, a vitreous product of volcanic activity; formations over 17 million years old have been found. Archaeologists have found man-made glass specimens that are five thousand years old.

  1. Nuclear Data Sheets for A = 204

    SciTech Connect

    Chiara, C.J.; Kondev, F.G.

    2010-01-15

    Evaluated nuclear structure and decay data for all nuclei within the A = 204 mass chain are presented. The experimental data are evaluated and best values for level and gamma-ray energies, quantum numbers, lifetimes, gamma-ray intensities, and other nuclear properties are recommended. Inconsistencies and discrepancies that exist in the literature are noted. This work supersedes the earlier evaluation by M.R. Schmorak (1994Sc24), published in Nuclear Data Sheets72, 409 (1994)

  2. Nuclear Data Sheets for A = 206

    SciTech Connect

    Kondev, F.G.

    2008-06-15

    Evaluated nuclear structure and decay data for all nuclei within the A = 206 mass chain are presented. The experimental data are evaluated and recommended best values for level and gamma-ray energies, quantum numbers, lifetimes, gamma-ray intensities and other nuclear properties are presented. Inconsistencies and discrepancies that exist in the literature are noted. This work supersedes the earlier evaluation by E. Browne (1999Br39), published in Nuclear Data Sheets88, 29 (1999)

  3. Nuclear Data Sheets for A = 207

    SciTech Connect

    Kondev, F.G.; Lalkovski, S.

    2011-03-15

    Evaluated nuclear structure and decay data for all nuclei within the A=207 mass chain are presented. The experimental data are evaluated and best values for level and gamma-ray energies, quantum numbers, lifetimes, gamma-ray intensities, and other nuclear properties are recommended. Inconsistencies and discrepancies that exist in the literature are noted. This work supersedes the earlier evaluation by M.J. Martin (1993Ma73), published in Nuclear Data Sheets70, 315 (1993).

  4. Nuclear Data Sheets for A = 216

    SciTech Connect

    Wu, S.-C.

    2007-05-15

    Evaluated spectroscopic data for all nuclei with mass number A = 216 are presented together with the relevant level schemes from radioactive decay and nuclear reaction studies. The experimental data are evaluated, inconsistencies and discrepancies are noted, and adopted values for level and {gamma}-ray energies, {gamma} intensities, as well as for other nuclear properties are given. The present evaluation supersedes the earlier one on A = 216 by A. Artna-Cohen (1997Ar04), published in Nuclear Data Sheets 80, 157 (1997)

  5. Nuclear Data Sheets for A = 112

    SciTech Connect

    Lalkovski, S.; Kondev, F.G.

    2015-02-15

    Evaluated nuclear structure and decay data for all nuclei within the A = 112 mass chain are presented. The experimental data are evaluated and best values for level and gamma-ray energies, quantum numbers, lifetimes, gamma-ray intensities, and other nuclear properties are recommended. Inconsistencies and discrepancies that exist in the literature are noted. This work supersedes the earlier evaluation by D. De Frenne and E. Jacobs (1996De55), published in Nuclear Data Sheets79, 639 (1996)

  6. Nuclear Data Sheets for A = 146

    NASA Astrophysics Data System (ADS)

    Khazov, Yu.; Rodionov, A.; Shulyak, G.

    2016-09-01

    Evaluated nuclear structure and decay data for all nuclei within the A = 146 mass chain are presented. The experimental data are evaluated and best values for level and gamma-ray energies, quantum numbers, lifetimes, gamma-ray intensities, and other nuclear properties are recommended. Inconsistencies and discrepancies that exist in the literature are noted. This work supersedes the earlier evaluation by L.K. Peker, J.K. Tuli (1997Pe22), published in Nuclear Data Sheets82, 187 (1997).

  7. Nuclear Data Sheets for A = 133

    SciTech Connect

    Khazov, Yu.; Rodionov, A.; Kondev, F.G.

    2011-04-15

    Evaluated nuclear structure and decay data for all nuclei within the A=133 mass chain are presented. The experimental data are evaluated and best values for level and gamma-ray energies, quantum numbers, lifetimes, gamma-ray intensities, and other nuclear properties are recommended. Inconsistencies and discrepancies that exist in the literature are noted. This work supersedes the earlier evaluation by S. Raab (1995Ra12), published in Nuclear Data Sheets75, 491 (1995).

  8. Multiple photon emission in heavy particle decays

    NASA Technical Reports Server (NTRS)

    Asakimori, K.; Burnett, T. H.; Cherry, M. L.; Christl, M. J.; Dake, S.; Derrickson, J. H.; Fountain, W. F.; Fuki, M.; Gregory, J. C.; Hayashi, T.

    1994-01-01

    Cosmic ray interactions, at energies above 1 TeV/nucleon, in emulsion chambers flown on high altitude balloons have yielded two events showing apparent decays of a heavy particle into one charged particle and four photons. The photons converted into electron pairs very close to the decay vertex. Attempts to explain this decay topology with known particle decays are presented. Unless both events represent a b yields u transition, which is statistically unlikely, then other known decay modes for charmed or bottom particles do not account satisfactorily for these observations. This could indicate, possibly, a new decay channel.

  9. Atomic radiations in the decay of medical radioisotopes: a physics perspective.

    PubMed

    Lee, B Q; Kibédi, T; Stuchbery, A E; Robertson, K A

    2012-01-01

    Auger electrons emitted in nuclear decay offer a unique tool to treat cancer cells at the scale of a DNA molecule. Over the last forty years many aspects of this promising research goal have been explored, however it is still not in the phase of serious clinical trials. In this paper, we review the physical processes of Auger emission in nuclear decay and present a new model being developed to evaluate the energy spectrum of Auger electrons, and hence overcome the limitations of existing computations.

  10. CP violation and rare decays

    SciTech Connect

    Quigg, C.

    2000-01-24

    After a brief essay on the current state of particle physics and possible approaches to the opportunities that have presented themselves, the author summarizes the contributions to the Third Workshop on Physics and Detectors for DA{Phi}NE that deal with CP Violation and Rare Decays.

  11. Rare decays at the Tevatron

    SciTech Connect

    Farrington, S.M.; /Liverpool U.

    2006-01-01

    The confidence level limits of the CDF and D0 searches for the B{sub s}{sup 0}, B{sub d}{sup 0} {yields} {mu}{sup +}{mu}{sup -} and B{sub s}{sup 0} {yields} {mu}{sup +}{mu}{sup -}{phi} rare decays are presented.

  12. First observation of the decay

    NASA Astrophysics Data System (ADS)

    Aaij, R.; Abellan Beteta, C.; Adeva, B.; Adinolfi, M.; Adrover, C.; Affolder, A.; Ajaltouni, Z.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; Anderlini, L.; Anderson, J.; Andreassen, R.; Appleby, R. B.; Aquines Gutierrez, O.; Archilli, F.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Bachmann, S.; Back, J. J.; Baesso, C.; Balagura, V.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Bauer, Th.; Bay, A.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Belogurov, S.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Benayoun, M.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bettler, M.-O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Bird, T.; Bizzeti, A.; Bjørnstad, P. M.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borgia, A.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Brambach, T.; van den Brand, J.; Bressieux, J.; Brett, D.; Britsch, M.; Britton, T.; Brook, N. H.; Brown, H.; Burducea, I.; Bursche, A.; Busetto, G.; Buytaert, J.; Cadeddu, S.; Callot, O.; Calvi, M.; Calvo Gomez, M.; Camboni, A.; Campana, P.; Campora Perez, D.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carranza-Mejia, H.; Carson, L.; Carvalho Akiba, K.; Casse, G.; Castillo Garcia, L.; Cattaneo, M.; Cauet, Ch.; Charles, M.; Charpentier, Ph.; Chen, P.; Chiapolini, N.; Chrzaszcz, M.; Ciba, K.; Cid Vidal, X.; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coca, C.; Coco, V.; Cogan, J.; Cogneras, E.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; David, P.; David, P. N. Y.; Davis, A.; De Bonis, I.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Silva, W.; De Simone, P.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Derkach, D.; Deschamps, O.; Dettori, F.; Di Canto, A.; Dijkstra, H.; Dogaru, M.; Donleavy, S.; Dordei, F.; Dosil Suárez, A.; Dossett, D.; Dovbnya, A.; Dupertuis, F.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; van Eijk, D.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Elsby, D.; Falabella, A.; Färber, C.; Fardell, G.; Farinelli, C.; Farry, S.; Fave, V.; Ferguson, D.; Fernandez Albor, V.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fitzpatrick, C.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Furcas, S.; Furfaro, E.; Gallas Torreira, A.; Galli, D.; Gandelman, M.; Gandini, P.; Gao, Y.; Garofoli, J.; Garosi, P.; Garra Tico, J.; Garrido, L.; Gaspar, C.; Gauld, R.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gibson, V.; Gligorov, V. V.; Göbel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gordon, H.; Grabalosa Gándara, M.; Graciani Diaz, R.; Granado Cardoso, L. A.; Graugés, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Grünberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hampson, T.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; Hartmann, T.; He, J.; Heijne, V.; Hennessy, K.; Henrard, P.; Hernando Morata, J. A.; van Herwijnen, E.; Hicheur, A.; Hicks, E.; Hill, D.; Hoballah, M.; Holtrop, M.; Hombach, C.; Hopchev, P.; Hulsbergen, W.; Hunt, P.; Huse, T.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Iakovenko, V.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jans, E.; Jaton, P.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Kaballo, M.; Kandybei, S.; Karacson, M.; Karbach, T. M.; Kenyon, I. R.; Kerzel, U.; Ketel, T.; Keune, A.; Khanji, B.; Kochebina, O.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Korolev, M.; Kozlinskiy, A.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kucharczyk, M.; Kudryavtsev, V.; Kvaratskheliya, T.; La Thi, V. N.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lambert, R. W.; Lanciotti, E.; Lanfranchi, G.; Langenbruch, C.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J.-P.; Lefèvre, R.; Leflat, A.; Lefrançois, J.; Leo, S.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Li Gioi, L.; Liles, M.; Lindner, R.; Linn, C.; Liu, B.; Liu, G.; Lohn, S.; Longstaff, I.; Lopes, J. H.; Lopez Asamar, E.; Lopez-March, N.; Lu, H.; Lucchesi, D.; Luisier, J.; Luo, H.; Machefert, F.; Machikhiliyan, I. V.; Maciuc, F.; Maev, O.; Malde, S.; Manca, G.; Mancinelli, G.; Marconi, U.; Märki, R.; Marks, J.; Martellotti, G.; Martens, A.; Martín Sánchez, A.; Martinelli, M.; Martinez Santos, D.; Martins Tostes, D.; Massafferri, A.; Matev, R.; Mathe, Z.; Matteuzzi, C.; Maurice, E.; Mazurov, A.; McCarthy, J.; McNab, A.; McNulty, R.; Meadows, B.; Meier, F.; Meissner, M.; Merk, M.; Milanes, D. A.; Minard, M.-N.; Molina Rodriguez, J.; Monteil, S.; Moran, D.; Morawski, P.; Morello, M. J.; Mountain, R.; Mous, I.; Muheim, F.; Müller, K.; Muresan, R.; Muryn, B.; Muster, B.; Naik, P.; Nakada, T.; Nandakumar, R.; Nasteva, I.; Needham, M.; Neufeld, N.; Nguyen, A. D.; Nguyen, T. D.; Nguyen-Mau, C.; Nicol, M.; Niess, V.; Niet, R.; Nikitin, N.; Nikodem, T.; Nomerotski, A.; Novoselov, A.; Oblakowska-Mucha, A.; Obraztsov, V.; Oggero, S.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Orlandea, M.; Otalora Goicochea, J. M.; Owen, P.; Oyanguren, A.; Pal, B. K.; Palano, A.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Parkes, C.; Parkinson, C. J.; Passaleva, G.; Patel, G. D.; Patel, M.; Patrick, G. N.; Patrignani, C.; Pavel-Nicorescu, C.; Pazos Alvarez, A.; Pellegrino, A.; Penso, G.; Pepe Altarelli, M.; Perazzini, S.; Perego, D. L.; Perez Trigo, E.; Pérez-Calero Yzquierdo, A.; Perret, P.; Perrin-Terrin, M.; Pessina, G.; Petridis, K.; Petrolini, A.; Phan, A.; Picatoste Olloqui, E.; Pietrzyk, B.; Pilař, T.; Pinci, D.; Playfer, S.; Plo Casasus, M.; Polci, F.; Polok, G.; Poluektov, A.; Polycarpo, E.; Popov, D.; Popovici, B.; Potterat, C.; Powell, A.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Puig Navarro, A.; Punzi, G.; Qian, W.; Rademacker, J. H.; Rakotomiaramanana, B.; Rangel, M. S.; Raniuk, I.; Rauschmayr, N.; Raven, G.; Redford, S.; Reid, M. M.; dos Reis, A. C.; Ricciardi, S.; Richards, A.; Rinnert, K.; Rives Molina, V.; Roa Romero, D. A.; Robbe, P.; Rodrigues, E.; Rodriguez Perez, P.; Roiser, S.; Romanovsky, V.; Romero Vidal, A.; Rouvinet, J.; Ruf, T.; Ruffini, F.; Ruiz, H.; Ruiz Valls, P.; Sabatino, G.; Saborido Silva, J. J.; Sagidova, N.; Sail, P.; Saitta, B.; Salzmann, C.; Sanmartin Sedes, B.; Sannino, M.; Santacesaria, R.; Santamarina Rios, C.; Santovetti, E.; Sapunov, M.; Sarti, A.; Satriano, C.; Satta, A.; Savrie, M.; Savrina, D.; Schaack, P.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmidt, B.; Schneider, O.; Schopper, A.; Schune, M.-H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Seco, M.; Semennikov, A.; Sepp, I.; Serra, N.; Serrano, J.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shatalov, P.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, O.; Shevchenko, V.; Shires, A.; Silva Coutinho, R.; Skwarnicki, T.; Smith, N. A.; Smith, E.; Smith, M.; Sokoloff, M. D.; Soler, F. J. P.; Soomro, F.; Souza, D.; De Paula, B. Souza; Spaan, B.; Sparkes, A.; Spradlin, P.; Stagni, F.; Stahl, S.; Steinkamp, O.; Stoica, S.; Stone, S.; Storaci, B.; Straticiuc, M.; Straumann, U.; Subbiah, V. K.; Swientek, S.; Syropoulos, V.; Szczekowski, M.; Szczypka, P.; Szumlak, T.; T'Jampens, S.; Teklishyn, M.; Teodorescu, E.; Teubert, F.; Thomas, C.; Thomas, E.; van Tilburg, J.; Tisserand, V.; Tobin, M.; Tolk, S.; Tonelli, D.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Tran, M. T.; Tresch, M.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Ubeda Garcia, M.; Ukleja, A.; Urner, D.; Uwer, U.; Vagnoni, V.; Valenti, G.; Vazquez Gomez, R.; Vazquez Regueiro, P.; Vecchi, S.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Vesterinen, M.; Viaud, B.; Vieira, D.; Vilasis-Cardona, X.; Vollhardt, A.; Volyanskyy, D.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voß, C.; Voss, H.; Waldi, R.; Wallace, R.; Wandernoth, S.; Wang, J.; Ward, D. R.; Watson, N. K.; Webber, A. D.; Websdale, D.; Whitehead, M.; Wicht, J.; Wiechczynski, J.; Wiedner, D.; Wiggers, L.; Wilkinson, G.; Williams, M. P.; Williams, M.; Wilson, F. F.; Wishahi, J.; Witek, M.; Wotton, S. A.; Wright, S.; Wu, S.; Wyllie, K.; Xie, Y.; Xing, Z.; Yang, Z.; Young, R.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zavertyaev, M.; Zhang, F.; Zhang, L.; Zhang, W. C.; Zhang, Y.; Zhelezov, A.; Zhokhov, A.; Zhong, L.; Zvyagin, A.

    2013-11-01

    The first observation of the decay is reported. The analysis is based on a data sample corresponding to an integrated luminosity of 1.0 fb-1 of pp collisions at TeV, collected with the LHCb detector. A yield of 30 ± 6 decays is found in the mass windows 1012.5 < M ( K + K -) < 1026.5 MeV/ c 2 and 746 < M( K - π +) < 1046 MeV/ c 2. The signal yield is found to be dominated by decays, and the corresponding branching fraction is measured to be = (1.10 ± 0.24 (stat) ± 0.14 (syst) ± 0.08 ( f d / f s )) × 10-6, where the uncertainties are statistical, systematic and from the ratio of fragmentation fractions f d / f s which accounts for the different production rate of B 0 and mesons. The significance of signal is 6.1 standard deviations. The fraction of longitudinal polarization in decays is found to be f 0 = 0.51 ± 0.15 (stat) ± 0.07 (syst). [Figure not available: see fulltext.

  13. Rare B decays at CDF

    SciTech Connect

    Farrington, Sinead M.; /Liverpool U.

    2006-10-01

    The confidence level limits of the CDF search for the B{sub s}{sup 0} and B{sub d}{sup 0} {yields} {mu}{sup +}{mu}{sup -} rare decays and the branching ratio measurement of B{sub s}{sup 0} {yields} D{sub s}{sup +} D{sub s}{sup -} are presented.

  14. Review of tau lepton decays

    SciTech Connect

    Stoker, D.P.

    1991-07-01

    Measurements of the {tau} decay modes are reviewed and compared with the predictions of the Standard Model. While the agreement is generally good, the status of the 1-prong puzzle'' remains controversial and a discrepancy between the measured leptonic branching fractions and the {tau} lifetime persists. Prospects for precision measurements at a Tau-Charm Factory are also reviewed. 20 refs., 2 tabs.

  15. Fermi's β-DECAY Theory

    NASA Astrophysics Data System (ADS)

    Yang, Chen Ning

    2013-05-01

    Throughout his lifetime Enrico Fermi (1901-1954) had considered his 1934 β-decay theory as his most important contribution to theoretical physics. E. Segrè (1905-1989) had vividly written about an episode at the inception of that paper:1...

  16. Time Modulation of the {beta}{sup +}-Decay Rate of H-Like {sup 140}Pr{sup 58+} Ions

    SciTech Connect

    Ivanov, A. N.; Kryshen, E. L.; Pitschmann, M.; Kienle, P.

    2008-10-31

    Recent experimental data at GSI on the rates of the number of daughter ions, produced by the nuclear K-shell electron capture (EC) decays of the H-like ions {sup 140}Pr{sup 58+} and {sup 142}Pm{sup 60+}, suggest that they are modulated in time with periods T{sub EC}{approx_equal}7 sec and amplitudes a{sub EC}{approx_equal}0.20. Since it is known that these ions are unstable also under the nuclear positron ({beta}{sup +}) decays, we study a possible time dependence of the nuclear {beta}{sup +}-decay rate of the H-like {sup 140}Pr{sup 58+} ion. We show that the time dependence of the {beta}{sup +}-decay rate of the H-like {sup 140}Pr{sup 58+} ion as well as any H-like heavy ions cannot be observed.

  17. Beta decay rates of neutron-rich nuclei

    NASA Astrophysics Data System (ADS)

    Marketin, Tomislav; Huther, Lutz; Petković, Jelena; Paar, Nils; Martínez-Pinedo, Gabriel

    2016-06-01

    Heavy element nucleosynthesis models involve various properties of thousands of nuclei in order to simulate the intricate details of the process. By necessity, as most of these nuclei cannot be studied in a controlled environment, these models must rely on the nuclear structure models for input. Of all the properties, the beta-decay half-lives are one of the most important ones due to their direct impact on the resulting abundance distributions. In this study we present the results of a large-scale calculation based on the relativistic nuclear energy density functional, where both the allowed and the first-forbidden transitions are studied in more than 5000 neutron-rich nuclei. Aside from the astrophysical applications, the results of this calculation can also be employed in the modeling of the electron and antineutrino spectra from nuclear reactors.

  18. Limit on Tensor Currents from ^{8}Li β Decay.

    PubMed

    Sternberg, M G; Segel, R; Scielzo, N D; Savard, G; Clark, J A; Bertone, P F; Buchinger, F; Burkey, M; Caldwell, S; Chaudhuri, A; Crawford, J E; Deibel, C M; Greene, J; Gulick, S; Lascar, D; Levand, A F; Li, G; Pérez Galván, A; Sharma, K S; Van Schelt, J; Yee, R M; Zabransky, B J

    2015-10-30

    In the standard model, the weak interaction is formulated with a purely vector-axial-vector (V-A) structure. Without restriction on the chirality of the neutrino, the most general limits on tensor currents from nuclear β decay are dominated by a single measurement of the β-ν[over ¯] correlation in ^{6}He β decay dating back over a half century. In the present work, the β-ν[over ¯]-α correlation in the β decay of ^{8}Li and subsequent α-particle breakup of the ^{8}Be^{*} daughter was measured. The results are consistent with a purely V-A interaction and in the case of couplings to right-handed neutrinos (C_{T}=-C_{T}^{'}) limits the tensor fraction to |C_{T}/C_{A}|^{2}<0.011 (95.5% C.L.). The measurement confirms the ^{6}He result using a different nuclear system and employing modern ion-trapping techniques subject to different systematic uncertainties. PMID:26565463

  19. Limit on Tensor Currents from ^{8}Li β Decay.

    PubMed

    Sternberg, M G; Segel, R; Scielzo, N D; Savard, G; Clark, J A; Bertone, P F; Buchinger, F; Burkey, M; Caldwell, S; Chaudhuri, A; Crawford, J E; Deibel, C M; Greene, J; Gulick, S; Lascar, D; Levand, A F; Li, G; Pérez Galván, A; Sharma, K S; Van Schelt, J; Yee, R M; Zabransky, B J

    2015-10-30

    In the standard model, the weak interaction is formulated with a purely vector-axial-vector (V-A) structure. Without restriction on the chirality of the neutrino, the most general limits on tensor currents from nuclear β decay are dominated by a single measurement of the β-ν[over ¯] correlation in ^{6}He β decay dating back over a half century. In the present work, the β-ν[over ¯]-α correlation in the β decay of ^{8}Li and subsequent α-particle breakup of the ^{8}Be^{*} daughter was measured. The results are consistent with a purely V-A interaction and in the case of couplings to right-handed neutrinos (C_{T}=-C_{T}^{'}) limits the tensor fraction to |C_{T}/C_{A}|^{2}<0.011 (95.5% C.L.). The measurement confirms the ^{6}He result using a different nuclear system and employing modern ion-trapping techniques subject to different systematic uncertainties.

  20. Free induction decay caused by a dipole field

    NASA Astrophysics Data System (ADS)

    Ziener, C. H.; Kurz, F. T.; Kampf, T.

    2015-03-01

    We analyze the free induction decay of nuclear spins under the influence of restricted diffusion in a magnetic dipole field around cylindrical objects. In contrast to previous publications no restrictions or simplifications concerning the diffusion process are made. By directly solving the Bloch-Torrey equation, analytical expressions for the magnetization are given in terms of an eigenfunction expansion. The field strength-dependent complex nature of the eigenvalue spectrum significantly influences the shape of the free induction decay. As the dipole field is the lowest order of the multipole expansion, the obtained results are important for understanding fundamental mechanisms of spin dephasing in many other applied fields of nuclear magnetic resonance such as biophysics or material science. The analytical methods are applied to interpret the spin dephasing in the free induction decay in cardiac muscle and skeletal muscle. A simple expression for the relevant transverse relaxation time is found in terms of the underlying microscopic parameters of the muscle tissue. The analytical results are in agreement with experimental data. These findings are important for the correct interpretation of magnetic resonance images for clinical diagnosis at all magnetic field strengths and therapy of cardiovascular diseases.

  1. Free induction decay caused by a dipole field.

    PubMed

    Ziener, C H; Kurz, F T; Kampf, T

    2015-03-01

    We analyze the free induction decay of nuclear spins under the influence of restricted diffusion in a magnetic dipole field around cylindrical objects. In contrast to previous publications no restrictions or simplifications concerning the diffusion process are made. By directly solving the Bloch-Torrey equation, analytical expressions for the magnetization are given in terms of an eigenfunction expansion. The field strength-dependent complex nature of the eigenvalue spectrum significantly influences the shape of the free induction decay. As the dipole field is the lowest order of the multipole expansion, the obtained results are important for understanding fundamental mechanisms of spin dephasing in many other applied fields of nuclear magnetic resonance such as biophysics or material science. The analytical methods are applied to interpret the spin dephasing in the free induction decay in cardiac muscle and skeletal muscle. A simple expression for the relevant transverse relaxation time is found in terms of the underlying microscopic parameters of the muscle tissue. The analytical results are in agreement with experimental data. These findings are important for the correct interpretation of magnetic resonance images for clinical diagnosis at all magnetic field strengths and therapy of cardiovascular diseases.

  2. Na-22 decay gamma rays from classical novae

    NASA Technical Reports Server (NTRS)

    Truran, James W.

    1993-01-01

    NASA Grant NAG 5-1565 has provided support for a program of theoretical research in nuclear astrophysics and related areas, focusing upon the possibility of detecting gamma rays from nearby novae. Particular attention has been given to the evaluation of the theoretical expectations for gamma ray emission from four possible sources: (1) the positron decays of the unstable CNO and fluorine isotopes that are transported to the surface regions of the envelope in the earliest stages of the outbursts; (2) Be-7 decay gamma rays, (3) Na-22 decay gamma rays released in the later stages of the outbursts; and (4) Al-26 decay gamma rays from novae and their possible contribution to Galactic emission. The critical questions of (1) the frequency of occurrence of ONeMg-enriched novae; (2) the expected Galactic distribution of the novae that produce 26Al; and (3) the nature of the observed soft X-ray emission from classical novae, have also been addressed. Considerable progress in research has been achieved on many of these fronts. Brief summaries of the results of several research projects are presented.

  3. Quantization in Classical Mechanics and Diffusion Mechanism of Alpha Decay, Cluster Radioactivity, Spontaneous Fission

    SciTech Connect

    Rusov, V. D.; Vlasenko, D. S.; Deliyergiyev, M. A.; Mavrodiev, S. Cht.

    2010-05-04

    Based on the Chetaev generalized theorem the Schredinger equation as the stability condition of trajectories in classical dynamics in the presence of dissipative forces is derived. In the framework of this approach the alternative model for unified description of alpha decay, spontaneous fission, cluster radioactivity and is developed. We show the possibility of the classical (without tunneling) description of radioactive decay of heavy nuclei, when the so called noise-induced transition or, in other words, the stochastic channel of radioactive decay conditioned by the Kramers diffusion mechanism is generated under certain conditions.Using the ENSDF nuclear data, we have found the parametrized solutions of the Kramers equation of the Langevin type by the Alexandrov dynamic auto-regularization method (REGN-Dubna program). These solutions describe with high-accuracy the dependences of half-life (the decay probability) of heavy radioactive nuclei on total kinetic energy of daughter decay products.Verification of the inverse problem solution in the framework of the universal Kramers description of alpha decay, spontaneous fission, cluster radioactivity, which based on the newest experimental data for alpha-decay of even-even superheavy nuclei (Z = 114, 116, 118), shows good coincidence of the experimental and theoretical dependences of half-life on alpha-decay energy.

  4. Quantization in Classical Mechanics and Diffusion Mechanism of Alpha Decay, Proton and Cluster Radioactivity, Spontaneous Fission

    SciTech Connect

    Rusov, V. D.; Vlasenko, D. S.; Deliyergiyev, M. A.; Mavrodiev, S. Cht.

    2010-01-01

    Based on the Chetaev generalized theorem the Schroedinger equation as the stability condition of trajectories in classical dynamics in the presence of dissipative forces is derived. In the framework of this approach the alternative model for unified description of alpha decay, spontaneous fission, cluster and proton radioactivity and is developed. We show the possibility of the classical (without tunneling) description of radioactive decay of heavy nuclei, when the so called noise-induced transition or, in other words, the stochastic channel of radioactive decay conditioned by the Kramers diffusion mechanism is generated under certain conditions.Using the ENSDF nuclear data, we have found the parametrized solutions of the Kramers equation of the Langevin type by the Alexandrov dynamic auto-regularization method (REGN-Dubna program). These solutions describe with high-accuracy the dependences of half-life (the decay probability) of heavy radioactive nuclei on total kinetic energy of daughter decay products.Verification of the inverse problem solution in the framework of the universal Kramers description of alpha decay, spontaneous fission, cluster and proton radioactivity, which based on the newest experimental data for alpha-decay of even-even superheavy nuclei (Z = 114, 116, 118), shows good coincidence of the experimental and theoretical dependences of half-life on alpha-decay energy.

  5. Nuclear Power in Space

    DOE R&D Accomplishments Database

    1994-01-01

    In the early years of the United States space program, lightweight batteries, fuel cells, and solar modules provided electric power for space missions. As missions became more ambitious and complex, power needs increased and scientists investigated various options to meet these challenging power requirements. One of the options was nuclear energy. By the mid-1950s, research had begun in earnest on ways to use nuclear power in space. These efforts resulted in the first radioisotope thermoelectric generators (RTGs), which are nuclear power generators build specifically for space and special terrestrial uses. These RTGs convert the heat generated from the natural decay of their radioactive fuel into electricity. RTGs have powered many spacecraft used for exploring the outer planets of the solar system and orbiting the sun and Earth. They have also landed on Mars and the moon. They provide the power that enables us to see and learn about even the farthermost objects in our solar system.

  6. Atlas of Nuclear Isomers

    SciTech Connect

    Jain, Ashok Kumar; Maheshwari, Bhoomika; Garg, Swati; Patial, Monika; Singh, Balraj

    2015-09-15

    We present an atlas of nuclear isomers containing the experimental data for the isomers with a half-life ≥ 10 ns together with their various properties such as excitation-energy, half-life, decay mode(s), spin-parity, energies and multipolarities of emitted gamma transitions, etc. The ENSDF database complemented by the XUNDL database has been extensively used in extracting the relevant data. Recent literature from primary nuclear physics journals, and the NSR bibliographic database have been searched to ensure that the compiled data Table is as complete and current as possible. The data from NUBASE-12 have also been checked for completeness, but as far as possible original references have been cited. Many interesting systematic features of nuclear isomers emerge, some of them new; these are discussed and presented in various graphs and figures. The cutoff date for the extraction of data from the literature is August 15, 2015.

  7. Relationship of perceived and actual motor competence in children.

    PubMed

    Raudsepp, Lennart; Liblik, Raino

    2002-06-01

    The purpose of this study was to examine the relationship between children's actual and perceived motor competence. 280 children between the ages of 10 and 13 years individually completed the Children's Physical Self-perception Profile which assesses perceptions of sport competence, physical conditioning, strength, body attractiveness, and general physical self-worth. The internal reliabilities (a) of the subscales ranged from .75 to .82. After completing the profile, the subject's actual motor competence was measured using tests of aerobic fitness and functional strength. Body fatness (sum of five skinfolds) was measured as an objective measure of perceived body attractiveness. Analysis of variance showed that boys and girls differed in perceived competence and actual motor competence. The boys showed higher perceived competence on four scores, but there was no sex difference in perception of body attractiveness. Correlations and regression analysis showed that actual and perceived motor competence were significantly but only moderately (r =.25-.56) correlated. In addition, items of perceived physical competence and age accounted for 17% (sit-ups) to 25% (endurance shuttle run) of the variance in actual motor competence of the children. These findings showed that 10- to 13-yr-old children can only moderately assess personal motor competence. PMID:12186225

  8. FDCSUSYDecay: An MSSM decay package

    NASA Astrophysics Data System (ADS)

    Qi, Wei; Wang, Jian-xiong

    2007-08-01

    FDCSUSYDecay is a FORTRAN program package generated by FDC (Feynman Diagram Calculation) system fully automatically. It is dedicated to calculate at tree-level all the possible 2-body decays of SUSY and Higgs particles in the Minimal Supersymmetric extension of the Standard Model (MSSM). The format of its output files complies with SUSY Les Houches Accord and can be easily imported by other packages. Program summaryManuscript title:FDCSUSYDecay: An MSSM decay package Authors:Wei Qi, Jian-xiong Wang Program title:FDCSUSYDecay (Version 1.00) Catalogue identifier:ADYV_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADYV_v1_0.html Program obtainable from:CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions:Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.:22 008 No. of bytes in distributed program, including test data, etc.:622 751 Distribution format:tar.gz Programming language:FORTRAN 77 Operating system:Linux Keywords:SUSY decay, MSSM, FDC PACS:02.70.-c, 12.60.Jv Classification:11.1, 11.6 External routines:CERNLIB 2003 (or up) Nature of problem: This package can calculate all the possible SUSY particle and Higgs 2-body decay width and branch ratio at tree-level in the MSSM model. Solution method: By running FDC, the Feynman rules for the MSSM model are generated, all the decay widths are calculated analytically and corresponding FORTRAN codes are generated for this package. Running time: Less than 1 second for both high-scale and low-scale modes on a Pentium IV 2.4 GHz machine (512 MB memory).

  9. Two-Neutrino Double-Beta Decay.

    NASA Astrophysics Data System (ADS)

    Guerard Ortego, Carlos-Kjell

    1992-01-01

    Two previous independent reports of 2 nubetabeta-decay by the ITEP-YPI collaboration, rm T_sp{1/2} {2nu}=(9+/- 1) times 10^ {20} yr (1sigma), and PNL-USC group, rm T_sp{1/2 }{2nu}=(1.12_sp{-0.26} {+0.48}) times 10^{21} yr (2sigma), were confirmed using a 0.25 Kg Ge(Li) detector isotopically enriched to 86% in ^{76}Ge. The detector was operated in the PNL-USC ultralow background facility in the Homestake gold mine for 168 days. Following a single correction to the data, a spectrum resembling that of the earlier PNL-USC experiment, with about the same intensity per ^{76}Ge atom, per year, was observed with a measured half life of rm T_sp{1/2}{2nu}=(9.2 _sp{-0.4}{+0.7} times 10 ^{20} y (2sigma). This experiment is one of two presented in this dissertation as original work. The half-life of the 2nubeta beta-decay of ^{100} Mo to the 1130 keV level of ^{100 }Ru has been measured to be rm T_{1/2}=(1.1_sp{-0.2} {+0.3}) times 10^{21} y (90% C.L.), by observing the 590.76 and 539.53 keV gamma rays emitted in the 0_sp{1}{+ }to 2^+to 0^+ de -excitation cascade. A review of the most relevant nuclear structure calculations is given, and their predictions are compared to the measurements from our two experiments.

  10. Double beta decay searches of 134Xe, 126Xe and 124Xe with large scale Xe detectors

    NASA Astrophysics Data System (ADS)

    Barros, N.; Thurn, J.; Zuber, K.

    2014-11-01

    The sensitivity for double beta decay studies of 134Xe and 124Xe is investigated assuming a potential large scale Xe experiment developed for dark matter searches depleted in 136Xe. The opportunity for an observation of the 2νββ - decay of 134Xe is explored for various scenarios. A positive observation should be possible for all calculated nuclear matrix elements. The detection of 2ν ECEC of 124Xe can be probed in all scenarios covering the theoretical predicted half-life uncertainties and a potential search for 126Xe is discussed. The sensitivity to {{β }+}EC decay of 124Xe is discussed and a positive observation might be possible, while {{β }+}{{β }+} decay still remains unobservable. The performed studies take into account solar pp-neutrino interactions, 85Kr beta decay and remaining 136Xe double beta decay as background components in the depleted detector.

  11. {beta} decay of odd-A As to Ge isotopes in the interacting boson-fermion model

    SciTech Connect

    Brant, S.; Yoshida, N.; Zuffi, L.

    2004-11-01

    The structure of odd-mass isotopes of As and Ge is described in the framework of the proton-neutron interacting boson-fermion model. The energy levels and the electromagnetic properties of {sup 69,71,73}As and {sup 69,71,73}Ge are calculated and compared with the experiment. The {beta}-decay rates from the As isotopes to the Ge isotopes are calculated. The calculated decays tend to be stronger than the observed ones. This may indicate a mixture of components outside the model space in the wave functions of actual nuclei. The effect of the higher-order terms in the decay operators seems small.

  12. The US Nuclear Data Network

    SciTech Connect

    Not Available

    1993-10-19

    This report discusses the following topics: US Nuclear Data Network Meeting; TUNL A=3--20 Data Project Activity Report 1993; INEL Mass-chain Evaluation Project Activity Report for 1993; 1993 Isotopes; Nuclear Data Project Activity Report; The NNDC Activity Report Parts A and B; Minutes of the Formats and Procedures Subcommittee; Evaluation of High-spin Nuclear Data for ENSDF and Table of Superdeformed Nuclear Bands; Proposal for Support of a Experimental High-spin; Data File/Data-Network Coordinator; Radioactive Decay and Applications; A Plan for a Horizontal Evaluation of Decay Data; ENSDF On-line System; The MacNuclide Project Expanding the Scope of the Nuclear Structure Reference File; ENSDAT: Evaluated Nuclear Structure Drawings and Tables; Cross Section Evaluation Working Group (CSEWG) and CSEWG Strategy Session; A Draft Proposal for a USNDN Program Advisory Council; Recommendations of Focus Group 1; Recommendations of Focus Group 2; Recommendations of Focus Group 3; Recommendations of Focus Group 4; The Table of Isotopes; The Isotopes CD-ROM; Electronic Table of Isotopes (ETOI); and Electronic Access to Nuclear Data.

  13. Pilot Eye Scanning under Actual Single Pilot Instrument Flight

    NASA Astrophysics Data System (ADS)

    Rinoie, Kenichi; Sunada, Yasuto

    Operations under single pilot instrument flight rules for general aviation aircraft is known to be one of the most demanding pilot tasks. Scanning numerous instruments plays a key role for perception and decision-making during flight. Flight experiments have been done by a single engine light airplane to investigate the pilot eye scanning technique for IFR flights. Comparisons between the results by an actual flight and those by a PC-based flight simulator are made. The experimental difficulties of pilot eye scanning measurements during the actual IFR flight are discussed.

  14. Meditation and college students' self-actualization and rated stress.

    PubMed

    Janowiak, J J; Hackman, R

    1994-10-01

    This paper concerns the efficacy of meditation and relaxation in promoting self-actualization and changes in self-reported stress among 62 college students. Two groups were given mantra meditation and a yogic relaxation technique referred to as Shavasana. Pre- and posttest measures were taken on the Personal Orientation Inventory and the Behavioral Relaxation Scale. Both groups showed significant increases in scores on self-actualization; however, no differences were found between groups. Meditation training was associated with larger gains in scores on measures of systematic relaxed behavior than of the relaxation training.

  15. Comparison of simulated and actual wind shear radar data products

    NASA Technical Reports Server (NTRS)

    Britt, Charles L.; Crittenden, Lucille H.

    1992-01-01

    Prior to the development of the NASA experimental wind shear radar system, extensive computer simulations were conducted to determine the performance of the radar in combined weather and ground clutter environments. The simulation of the radar used analytical microburst models to determine weather returns and synthetic aperture radar (SAR) maps to determine ground clutter returns. These simulations were used to guide the development of hazard detection algorithms and to predict their performance. The structure of the radar simulation is reviewed. Actual flight data results from the Orlando and Denver tests are compared with simulated results. Areas of agreement and disagreement of actual and simulated results are shown.

  16. Nuclear Data on the WWW

    NASA Astrophysics Data System (ADS)

    Firestone, Richard B.; Chu, S. Y. Frank; Ekstrom, L. Peter; Wu, Shiu-Chin; Singh, Balraj

    1997-10-01

    The Isotopes Project is developing Internet home pages to provide data for decay.html>radioactive decay, nuclear structure, nuclear astrophysics, spontaneous fission, thermal neutron capture, and atomic masses. These home pages can be accessed from the Table of Isotopes home page at http://isotopes.lbl.gov/isotopes/toi.html. Data from the Evaluated Nuclear Structure Data File (ENSDF) is now available on the WWW in Nuclear Data Sheet style tables, complete with comments and hypertext linked footnotes. Bibliographic information from the Nuclear Science Reference (NSR) file can be searched on the WWW by combinations of author, A, Z, reaction, and various keywords. Decay gamma-ray data from several databases can be searched by energy. The Table of Superdeformed Nuclear Bands and Fission Isomers is continously updated. Reaction rates from Hoffman and Woosley and from Thielemann, fission yields from England and Rider, thermal neutron cross-sections from BNL-325, atomic masses from Audi, and skeleton scheme drawings and nuclear charts from the Table of Isotopes are among the information available through these websites. The nuclear data home pages are accessed by over 3500 different users each month.

  17. Future short baseline neutrino searches with nuclear decays

    SciTech Connect

    Caccianiga, Barbara

    2015-07-15

    Several anomalies coming from neutrino experiments may be pointing towards new physics: these hints suggest the existence of one (or more) sterile neutrinos. We discuss some of the experiments proposed to verify (or disproof) this hypothesis by using an intense radioactive source in proximity of large neutrino detectors.

  18. Method for utilizing decay heat from radioactive nuclear wastes

    DOEpatents

    Busey, H.M.

    1974-10-14

    Management of radioactive heat-producing waste material while safely utilizing the heat thereof is accomplished by encapsulating the wastes after a cooling period, transporting the capsules to a facility including a plurality of vertically disposed storage tubes, lowering the capsules as they arrive at the facility into the storage tubes, cooling the storage tubes by circulating a gas thereover, employing the so heated gas to obtain an economically beneficial result, and continually adding waste capsules to the facility as they arrive thereat over a substantial period of time.

  19. Stellar structures and the enigma of pulsars rotation frequency decay

    NASA Astrophysics Data System (ADS)

    de Oliveira, H. O.; Marinho, R. M., Jr.; Maglhaes, N. S.

    2015-07-01

    Pulsars are astrophysical objects normally modelled as compact neutron stars that originated from the collapse of another star. This model, that we name canonical, assumes that pulsars are described by spherical magnetized dipoles that rotate, usually with the magnetic axis misaligned to the rotation axis. This misalignment would be responsible for the observation of radiation emitted in well-defined time intervals in a certain direction (lighthouse effect), the typical observational characteristic of this kind of star. It has been noticed that the rotation frequency of pulsars is slowly decaying with time (spin down), implying a gradual decrease of the rotational angular velocity (Ω). Such decay can be quantified by a dimensionless parameter called “braking index” (“n”), given by n = ΩΩ/(Ω)2, where a dot indicates a time derivative. The canonical model predicts that this index has one only value for all pulsars, equal to three. However, observational data indicate that actual braking indices are less than three, representing an enigma. The main goal of this research is the exploration of a more precise model for pulsars’ rotation frequency decay.

  20. Gaussian Confinement in a Jkj Decay Model

    NASA Astrophysics Data System (ADS)

    da Silva, Mario L. L.; Hadjimichef, Dimiter; Vasconcellos, Cesar A. Z.

    In microscopic decay models, one attempts to describe hadron strong decays in terms of quark and gluon degrees of freedom. We begin by assuming that strong decays are driven by the same interquark Hamiltonian which determines the spectrum, and that it incorporates gaussian confinement. An A → BC decay matrix element of the JKJ Hamiltonian involves a pair-production current matrix elements times a scatering matrix element. Diagrammatically this corresponds to an interaction between an initial line and produced pair.