WorldWideScience

Sample records for nuclear collective excitations

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

    International Nuclear Information System (INIS)

    Ogawa, K.

    1980-04-01

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

  2. Sound-like collective mode excitation with pion absorption in nuclear matter

    International Nuclear Information System (INIS)

    Qiu Xijiun; Shen Jianguo; Huang Lingfang

    1985-01-01

    The relativistic mean field theory consistent with bulk properties of nuclear matter is extended to study the excitations of the sound-like collective modes in nuclear matter. Corresponding relativistic mean field equations are solved numerically and self-consistently. The effective mass of nucleon, the speed of the sound and the amplitude of the sound-like solution are calculated. When the nuclear density is near or greater than the saturation density, the sound-like non-trivial solution could be found

  3. Coulomb-nuclear interference (CNI) results of the collective quadrupolar excitations in odd and even Ru isotopes

    International Nuclear Information System (INIS)

    Rodrigues, C.L.; Rodrigues, M.R.D.; Borello-Lewin, T.; Horodynski-Matsushigue, L.B.; Duarte, J. L.M.; Hanninger, G.N.; Ukita, G.M.

    2004-01-01

    The study of the odd 99,101 Ru nuclei complements the investigation of the collectivity of the first quadrupolar excitations in 100,102,104 Ru. Angular distributions for the 99,101 Ru(d, d') reactions at 13 MeV were obtained in the Pelletron Laboratory using nuclear emulsion plates on the focal plane of the Enge spectrograph. A Coulomb- Nuclear Interference analysis employing DWBA-DOMP predictions with global optical potential parameters was applied to the excitation of states which could belong to the multiplet built on the first quadrupolar excitation of the core. In the analysis, three states were identified for each of the isotopes and associated, respectively, with adopted levels in the Nuclear Data Sheets Compilation of Jπ = 5=2 + , 7=2 + and 9=2 + . Through the comparison of experimental and predicted cross section angular distributions, the values of (δ L N ) 2 and of the ratio C = δ L C /δ L N were obtained. (author)

  4. Coulomb-nuclear interference (CNI) results of the collective quadrupolar excitations in odd and even Ru isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, C.L.; Rodrigues, M.R.D.; Borello-Lewin, T.; Horodynski-Matsushigue, L.B.; Duarte, J. L.M.; Hanninger, G.N. [Sao Paulo Univ., SP (Brazil). Inst. de Fisica; Ukita, G.M. [Universidade de Santo Amaro, SP (Brazil). Faculdade de Psicologia

    2004-09-15

    The study of the odd {sup 99,101}Ru nuclei complements the investigation of the collectivity of the first quadrupolar excitations in {sup 100,102,104}Ru. Angular distributions for the {sup 99,101}Ru(d, d') reactions at 13 MeV were obtained in the Pelletron Laboratory using nuclear emulsion plates on the focal plane of the Enge spectrograph. A Coulomb- Nuclear Interference analysis employing DWBA-DOMP predictions with global optical potential parameters was applied to the excitation of states which could belong to the multiplet built on the first quadrupolar excitation of the core. In the analysis, three states were identified for each of the isotopes and associated, respectively, with adopted levels in the Nuclear Data Sheets Compilation of J{pi} = 5=2{sup +}, 7=2{sup +} and 9=2{sup +}. Through the comparison of experimental and predicted cross section angular distributions, the values of ({delta}{sup L}{sub N}){sup 2} and of the ratio C = {delta}{sub L}{sup C} /{delta}{sub L}{sup N} were obtained. (author)

  5. Microscopic approach in Inelastic Heavy-Ions Scattering with Excitation of Nuclear Collective States

    International Nuclear Information System (INIS)

    Lukyanov, K.V.; Zemlyanya, E.V.; Khtina, I.N.; Lukyanov, V.K; Metawe, Z.; Hanna, K.M.

    2008-01-01

    In the density distribution of a deformed target-nucleus,the spherical λ = 0 and the deformed λ = 2 parts were considered. On this basis, the corresponding potential parts U 0 and U i nt(2) of a double-folding microscopic nucleus-nucleus optical potential are obtained. Then, for these potentials and by using the coupled- channel technique (ECIS), the elastic and inelastic amplitudes are calculated for 17 O heavy ions scattering on 2 + collective excited stat of various target nuclei. Besides,the same cross-sections are calculated in the frame of an adiabatic approach of the eikonal approximation, where the inelastic amplitude is the linear function of U i nt (2).Both the obtained results are compared with the experimental data, and also discus their efficiency in predicting the deformation parameters of nuclei

  6. Collective nuclear dynamics. Abstracts

    International Nuclear Information System (INIS)

    Abrosimov, V.I.; Kolomietz, V.M.

    1994-01-01

    The fourth International school on nuclear physics was help on 29 Aug - 7 Sep, 1994 in Ukraine. The specialists discussed following subjects: liquid drop and the shell correction method; nuclear deformation energy and fission; nuclear structure at high spins, superdeformed states, structure of excited and exotic nuclei; nuclear fluid dynamics and large scale collective motion; order and chaos as they relate to the collective motion; quantum and interference phenomena in nuclear collisions; quasi-fission and multinucleon fragmentation effects; shell effects in non-nuclear systems; new nuclear facilities

  7. Collective excitations in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Chomaz, Ph. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France); Collaboration: La Direction des Sciences de la Matiere du CEA (FR); Le Fonds National de la Recherche Scientifique de Belgique (BE)

    1998-12-31

    The properties of the nucleus cannot be reduced to the properties of its constituents: it is a complex system. The fact that many properties of the nucleus are consequences of the existence of mean-field potential is a manifestation of this complexity. In particular, the nucleons can thus self-organize in collective motions such as giant resonances. Therefore the study of this collective motions is a very good tool to understand the properties of the nucleus itself. The purpose of this article is to stress some aspects of these collective vibrations. We have studied how an ensemble of fermions as the nucleus can self-organize in collective vibrations which are behaving like a gas of bosons in weak interaction. Understanding of these phenomena remains one of the important subjects of actuality in the context of quantal systems in strong interaction. In particular, the study of the states with one or two vibration quanta provides a direct information on the structure of nuclei close to their ground states. Moreover, some collective states appear to be very robust against the onset of chaos. This is the case of the hot giant dipole built on top of a hot nucleus which seems to survive up to rather high temperatures. Their sudden disappearance is still a subject of controversy. It may be that the mean-field and the associated collective states are playing a crucial role also in catastrophic processes such as the phase-transitions. Indeed, when the system is diluted the collective vibrations may become unstable and it seems that these unstable modes provide a natural explanation to the self organization of the system in drops. Finally, considering the diversity of the different structures of exotic nuclei one may expect new vibration types. All these studies are showing the diversity of the collective motions of strongly correlated quantum systems such as the nucleus but many open questions remain to be solved. (authors) 304 refs., 53 figs., 5 tabs.

  8. Collective excitations in nuclei

    International Nuclear Information System (INIS)

    Chomaz, Ph.

    1998-01-01

    The properties of the nucleus cannot be reduced to the properties of its constituents: it is a complex system. The fact that many properties of the nucleus are consequences of the existence of mean-field potential is a manifestation of this complexity. In particular, the nucleons can thus self-organize in collective motions such as giant resonances. Therefore the study of this collective motions is a very good tool to understand the properties of the nucleus itself. The purpose of this article is to stress some aspects of these collective vibrations. We have studied how an ensemble of fermions as the nucleus can self-organize in collective vibrations which are behaving like a gas of bosons in weak interaction. Understanding of these phenomena remains one of the important subjects of actuality in the context of quantal systems in strong interaction. In particular, the study of the states with one or two vibration quanta provides a direct information on the structure of nuclei close to their ground states. Moreover, some collective states appear to be very robust against the onset of chaos. This is the case of the hot giant dipole built on top of a hot nucleus which seems to survive up to rather high temperatures. Their sudden disappearance is still a subject of controversy. It may be that the mean-field and the associated collective states are playing a crucial role also in catastrophic processes such as the phase-transitions. Indeed, when the system is diluted the collective vibrations may become unstable and it seems that these unstable modes provide a natural explanation to the self organization of the system in drops. Finally, considering the diversity of the different structures of exotic nuclei one may expect new vibration types. All these studies are showing the diversity of the collective motions of strongly correlated quantum systems such as the nucleus but many open questions remain to be solved. (authors)

  9. Collective excitations in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Chomaz, Ph

    1997-12-31

    The properties of the nucleus cannot be reduced to the properties of its constituents: it is a complex system. The fact that many properties of the nucleus are consequences of the existence of mean-field potential is a manifestation of this complexity. In particular the nucleons can thus self-organize in collective motions such as giant resonances. Therefore the study of these collective motions is a very good to understand the properties of the nucleus itself. The purpose of this article was to stress some aspects of these collective vibrations. In particular we have studied how an ensemble of fermions as the nucleus can self-organize in collective vibrations which are behaving like a gas of bosons in weak interaction. The understanding of these phenomena remains one of the important subjects of actually in the context of quantal systems in strong interaction. In particular the study of the states with one or two vibration quanta provides a direct information on the structure if nuclei close to their ground states. (author) 270 refs.

  10. Collective excitations in nuclei

    International Nuclear Information System (INIS)

    Chomaz, Ph.

    1997-01-01

    The properties of the nucleus cannot be reduced to the properties of its constituents: it is a complex system. The fact that many properties of the nucleus are consequences of the existence of mean-field potential is a manifestation of this complexity. In particular the nucleons can thus self-organize in collective motions such as giant resonances. Therefore the study of these collective motions is a very good to understand the properties of the nucleus itself. The purpose of this article was to stress some aspects of these collective vibrations. In particular we have studied how an ensemble of fermions as the nucleus can self-organize in collective vibrations which are behaving like a gas of bosons in weak interaction. The understanding of these phenomena remains one of the important subjects of actually in the context of quantal systems in strong interaction. In particular the study of the states with one or two vibration quanta provides a direct information on the structure if nuclei close to their ground states. (author)

  11. Nuclear excitation in muonic gold

    CERN Document Server

    Robert Tissot, B; Debrunner, P; Engfer, R; Link, R; Schellenberg, L; Schneuwly, H; Walter, H K

    1973-01-01

    Energies and intensities of muonic X-rays in gold were measured at the CERN muon channel with an experimental set-up as described by Backe et al. (1972). The 2p-1s and 3d-2p transitions could only be analysed taking into account beside the static quadrupole interaction a dynamical hyperfine interaction of the 2p states, which leads to an excitation of the first four nuclear levels. The dynamical hyperfine interaction was calculated using the core excitation model (de Shalit, (1961)). (0 refs).

  12. A truncated spherical shell model for nuclear collective excitations: Applications to the odd-mass systems, neutron-proton systems, and other topics

    International Nuclear Information System (INIS)

    Wu, Hua.

    1989-01-01

    One of the most elusive quantum system in nature is the nucleus, which is a strongly interacting many body system. In the hadronic (a la neutrons and protons) phase, the primary concern of this thesis, the nucleus' single particle excitations are intertwined with their various collective excitations. Although the underpinning of the nucleus is the spherical shell model, it is rendered powerless without a severe, but intelligent truncation of the infinite Hilbert space. The recently proposed Fermion Dynamical Symmetry Model (FDSM) is precisely such a truncation scheme and in which a symmetry-dictated truncation scheme is introduced in nuclear physics for the first time. In this thesis, extensions and explorations of the FDSM are made to specifically study the odd mass (where the most intricate mixing of the single particle and the collective excitations are observed) and the neutron-proton systems. In particular, the author finds that the previously successful phenomenological particle-rotor-model of the Copenhagen school can now be well understood microscopically via the FDSM. Furthermore, the well known Coriolis attenuation and variable moment of inertia effects are naturally understood from the model as well. A computer code FDUO was written by one of us to study, for the first time, the numerical implications of the FDSM. Several collective modes were found even when the system does not admit a group chain description. In addition, the code is most suitable to study the connection between level statistical behavior (a at Gaussian Orthogonal Ensemble) and dynamical symmetry. It is found that there exist critical region of the interaction parameter space were the system behaves chaotically. This information is certainly crucial to understanding quantum chaotic behavior

  13. Nuclear transitions induced by atomic excitations

    International Nuclear Information System (INIS)

    Dyer, P.L.; Bounds, J.A.; Haight, R.C.; Luk, T.S.

    1988-01-01

    In the two-step pumping scheme for a gamma-ray laser, an essential step is that of exciting the nucleus from a long-lived storage isomer to a nearby short-lived state that then decays to the upper lasing level. An experiment is in progress to induce this transfer by first exciting the atomic electrons with uv photons. The incident photons couple well to the electrons, which then couple via a virtual photon to the nucleus. As a test case, excitation of the 235 U nucleus is being sought, using a high-brightness uv laser. The excited nuclear state, having a 26-minute half-life, decays by internal converison, resulting in emission of an atomic electron. A pulsed infrared laser produces an atomic beam of 235 U which is then bombarded by the uv laser beam. Ions are collected, and conversion electrons are detected by a channel elctron multiplier. In preliminary experiments, an upper limit of 7 x 10 -5 has been obtained for the probability of exciting a 235 U atom in the uv beam for one picosecond at an intensity of about 10 15 W/cm 2 . Experiments with higher sensitivities and at higher uv beam intensities are underway. 6 refs., 1 fig

  14. Neutrino-induced nuclear excitations

    Energy Technology Data Exchange (ETDEWEB)

    Belusevic, R. [National Laboratory for High Energy Physics (KEK), Oho 1-1, Tsukuba-shi, Ibaraki-ken, 305 (Japan)

    1995-04-01

    We present an improved, compared to that of Belusevic and Rein, theoretical value of the cross section for the neutrino-induced nuclear excitation of iron. This result is based on a measurement of the photoabsorption cross section on the same nucleus, which can be related to the transverse part of the neutrino cross section via the conserved vector current hypothesis. The longitudinal part is related to the pion absorption cross section through the partial conservation of the axial-vector current, and thus reflects the spontaneous breaking of chiral symmetry. A general formula for the excitation cross section is derived, which is valid for both low and high incident neutrino energies. When caused by a weak neutral current, this process may play an important role in core-collapse supernovae. It can also be detected using low-temperature techniques with the purpose of cosmological and weak-interaction studies. A new estimate of the cross sections for neutrino-induced nonscaling processes described by Belusevic and Rein is discussed in the context of two experiments using iron targets, but at very different beam energies.

  15. Nuclear excitations and reaction mechanisms

    International Nuclear Information System (INIS)

    Fallieros, S.; Levin, F.S.

    1990-01-01

    The main theme of this report is the study and interpretation of the sequence of events that occur during the collisions of nuclear particles. Some of the processes discussed in parts A and B involve short range interactions; others involve interactions of long range. In most of part A one of the particles in the initial or in the final state (or in both) is a photon, which serves as a probe of the second particle, which may be a nucleus, a proton, a pion or any other hadron. The complexity of the processes taking place during the collisions makes it necessary to simplify some aspects of the physical problem. This leads to the introduction of modals which are used to describe a limited number of features in as much detail as possible. The main interest is the understanding of the hadronic excitations which result from the absorption of a photon and the determination of the fundamental structure constants of the target particle. In part B, all the particles are hadrons. The purpose here is to develop and apply optimal quantal methods appropriate for describing the interacting systems. Of particular interest are three-particle collision systems in which the final state consists of three free particles. Part B also considers the process of nuclear fusion as catalyzed by bound muons

  16. Macroscopic dynamics of thermal nuclear excitations

    International Nuclear Information System (INIS)

    Bastrukov, S.I.; Deak, F.; Kiss, A.; Seres, Z.

    1989-11-01

    The concept of kinetic temperature as a local dynamical variable of thermal nuclear collective motion is formulated using long-mean-free-path approach based on the Landau-Vlasov kinetic equation. In the Fermi drop model the thermal fluid dynamics of the spherical nucleus is analyzed. It is shown that in a compressible Fermi liquid the temperature pulses propagate in the form of spherical wave in phase with the acoustic wave. The thermal and compressional excitations are caused by the isotropic harmonic oscillations of the Fermi sphere in momentum space. (author) 25 refs.; 2 figs

  17. Nuclear structure at high excitation energies

    Indian Academy of Sciences (India)

    Study of the structure of nuclei in extreme conditions of angular momentum, excitation energy (temperature) and isospin has recently become a very interesting and active area of research in nuclear physics. Experimentally compound nuclei can be formed at high excitation energies and in high angular momentum states ...

  18. Nuclear excitations in the nuclear response theory

    International Nuclear Information System (INIS)

    Nguyen Van Giai.

    1983-01-01

    The Random Phase Approximation is used to calculate the response of a nucleus to an external field. The method allows a full treatment of continuum effects. Effective interactions to be used are discussed, and the consistency between the mean field and the residual interaction is stressed. Some applications to excitation properties of spherical nuclei are shown

  19. Collective excitations of harmonically trapped ideal gases

    NARCIS (Netherlands)

    Van Schaeybroeck, B.; Lazarides, A.

    2009-01-01

    We theoretically study the collective excitations of an ideal gas confined in an isotropic harmonic trap. We give an exact solution to the Boltzmann-Vlasov equation; as expected for a single-component system, the associated mode frequencies are integer multiples of the trapping frequency. We show

  20. Photemission and the influence of collective excitations

    International Nuclear Information System (INIS)

    Johnson, Peter D.

    2002-01-01

    The development of new capabilities in high resolution photoemission is allowing detailed studies of the role of collective many-body excitations in the decay of a photohole. This in turn provides new insights into the physics of condensed matter systems, in particular the strongly-correlated systems, which exhibit a rich variety of exotic phenomena including high Tc superconductivity

  1. Nuclear excitations and reaction mechanisms

    International Nuclear Information System (INIS)

    Fallieros, S.; Levin, F.S.

    1989-01-01

    This Progress Report describes the work of the Brown University Nuclear Theory Group for the period 1 August 1988--31 July 1989 under Grant FG02-87ER40334. Completed and on-going research includes various theoretical and numerical studies on: virtual photons, electric polarizability, the Cabibo-Radicati sum rule, photon scattering, electron scattering, electron scattering sum rules, muon catalyzed fusion, few body collisions and breakup phenomena. Since it accompanies the three-year Renewal Proposal of the Group, it goes into more detail than our typical one-year reports

  2. Nuclear Excitations by Antiprotons and Antiprotonic Atoms

    CERN Multimedia

    2002-01-01

    The proposal aims at the investigation of nuclear excitations following the absorption and annihilation of stopped antiprotons in heavier nuclei and at the same time at the study of the properties of antiprotonic atoms. The experimental arrangement will consist of a scintillation counter telescope for the low momentum antiproton beam from LEAR, a beam degrader, a pion multiplicity counter, a monoisotopic target and Ge detectors for radiation and charged particles. The data are stored by an on-line computer.\\\\ \\\\ The Ge detectors register antiprotonic x-rays and nuclear @g-rays which are used to identify the residual nucleus and its excitation and spin state. Coincidences between the two detectors will indicate from which quantum state the antiprotons are absorbed and to which nuclear states the various reactions are leading. The measured pion multiplicity characterizes the annihilation process. Ge&hyphn. and Si-telescopes identify charged particles and determine their energies.\\\\ \\\\ The experiment will gi...

  3. Collective motion in nuclei and its excitation in scattering

    International Nuclear Information System (INIS)

    Thijssen, W.J.G.

    1981-01-01

    This thesis deals with a number of subjects which have the collective nuclear model as a common denominator. The collective nuclear model describes aspects of the nucleus, such as excitation energies, electromagnetic transition probabilities and inelastic scattering with excitation of the lowest-lying levels, not by means of the individual nucleon degrees of freedom but instead with collective variables describing the shape of the nucleus. The first subject concerns a complete set of states, possessing definite angular momentum quantum numbers, in which eigenstates of a more general collective model may be expanded. The second subject concerns the use of scattering results in an analysis of nuclear structure, both in the harmonic vibration model and in a more general collective model. For such an analysis the author tries to find a method for calculating scattering results from the collective model in a less time-consuming way than is required for full conventional coupled-channel calculations. In this light he studies the combined adiabatic (or ''energy-sudden'') and ''centrifugal-sudden'' approximations. (Auth.)

  4. Excitation of nuclear states by synchrotron radiation

    International Nuclear Information System (INIS)

    Olariu, Albert

    2003-01-01

    We study the excitation of nuclear states by gamma ray beams of energy up to 200 keV produced as synchrotron radiation. We consider the possibility to populate an excited state |i> in two steps, from the ground state |g> to an intermediary state |n> which decays by gamma emission or internal conversion to a lower state |i>. The aim of this study is to establish that the probability P 2 of the two-step transition |g> → |n> → |i> should be greater than the probability P 1 of the direct transition |g> → |i>. The probabilities P 1 and P 2 correspond to a radiation pulse of duration equal to the half-time of the state |i>. We have written a computer program in C++ which computes the probability P 2 , the ratio P 2 /P 1 and the rate C 2 of the two-step transitions for any nuclei and different configurations of states. The program uses a database which contains information on the energy levels, half-lives, spins and parities of nuclear states and on the relative intensities of the nuclear transitions. If the half-lives or the relative intensities are not known the program uses the Weisskopf estimates for the transition half-lives. An interpolation program of internal conversion coefficients has also been used. We listed the values obtained for P 2 , P 2 /P 1 and C 2 in a number of cases in which P 2 is significant from the 2900 considered cases. The states |i> and |n> have the energies E i and E n , the corresponding half-lives being t i and t n . The spectral density of the synchrotron radiation has been considered to be 10 12 photons cm -2 s -1 eV -1 . We listed only the cases for which the relative intensities of the transitions from levels |n> and |i> to lower states are known. The calculations carried out in this study allowed us to identify nuclei for which P 2 has relatively great values. In the listed cases P 2 /P 1 >>1, so that the two-step excitation by synchrotron radiation is more efficient than the direct excitation |g> → |i>. For a sample having 10

  5. Collective electronic excitations in C60 crystals

    International Nuclear Information System (INIS)

    Wu, X.; Ulloa, S.E.

    1994-01-01

    We present a theoretical study of the electronic excitations in fullerene crystals by calculating the density-density correlation function in a fully nonlocal linear response theory. Our results indicate that the collective features associates with the π→π * transitions show strong anisotropic properties, with peaks changing by as much as 0.7 eV in different directions. Meanwhile, the calculated mode dispersion exhibits rather weak wave-number dependence along a given direction, in general agreement with experimental results. The oscillator strength also shows anisotropic behavior, with significant weight redistribution for different directions. We also analyze this system in terms of a classical point-dipole array model, and show that this simple model approximates well the quantum results

  6. Excitations in superfluid systems: contributions of the nuclear structure; Excitations dans les systemes superfluides: contributions de la structure nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Khan, E

    2005-12-15

    The author presents successively the theoretical aspect, the experimental aspect and the applied aspect of excitations in nuclear structures. The quasi-particle random phase approximation (QRPA) tool is first described. Recent approaches on QRPA are based on the theory of the density function where the ground state and excited states are described from the same nucleon-nucleon interaction. 2 methods for measuring the collective excitations are then presented: the proton scattering that has the potentiality to investigate the evolution of magicity, the second method is in fact a new method for measuring the giant mono-polar resonance (GMP) in exotic nuclei. Nuclear reactions are considered as a compulsory step on the way from observables like cross-sections to nuclear structure. The author highlights the assets of the convolution model that can generate the optical potential from the effective nucleon-nucleon interaction and from proton and neutron densities of the nuclei involved. R-processes in nucleosynthesis and neutron stars are reviewed as applications of collective excitations in the field of nuclear astrophysics. (A.C.)

  7. Hyperon excitation in nuclear coulomb field

    International Nuclear Information System (INIS)

    Vanyashin, A.V.; Nikitin, Yu.P.; Shan'gin, A.A.

    1981-01-01

    A possibility is studied to measure radiative decay partial widths from the 3/2 + decuplet hyperon resonances by means of the Coulomb excitation method of the octet hyperons. The expected contributions from the strong and electromagnetic interactions in the coherence range to the hyperon excitation cross sections on heavy nuclei and on the 4 He nucleus are estimated. The particle angular distributions in the reactions Σ-+A→Σ-(1385)+A and Λ+A→Σ 0 (1385)+A are analysed in order to determine the energy range where the background conditions are the most favorable to extract the electromagnetic mechanism of the hyperon excitation [ru

  8. Gross properties of nuclei and nuclear excitations XXI

    International Nuclear Information System (INIS)

    Feldmeier, H.

    1993-01-01

    These proceedings contain the articles and contributed papers presented at the named workshop. They are concerned with highly excited nuclear matter and relativistic heavy ion reactions together with some related topics. See hints under the relevant topics. (HSI)

  9. Gross properties of nuclei and nuclear excitations

    International Nuclear Information System (INIS)

    Feldmeier, H.

    1989-01-01

    These proceedings contain the articles presented at the named workshop. These concern new developments in nuclear structure studies, relativistic heavy ion reactions, and advanced techniques for nuclear spectroscopy. (HSI)

  10. Gross properties of nuclei and nuclear excitations

    International Nuclear Information System (INIS)

    Feldmeier, H.

    1992-01-01

    Heavy ion reactions are the main topics of the workshop. The different aspects that are discussed are: nuclear matter at relativistic energies, the transformation to quark matter, particle production, spallation and theoretical models for nuclear reaction kinetics. (BBOE)

  11. Microstructure ion Nuclear Spectra at High Excitation

    International Nuclear Information System (INIS)

    Ericson, T.E.O.

    1969-01-01

    The statistical microstructure of highly excited systems is illustrated by the distribution and fluctuations of levels, widths and cross-sections of nuclei both for the case of sharp resonances and the continuum case. The coexistence of simple modes of excitation with statistical effects in terms of strength functions is illustrated by isobaric analogue states. The analogy is made with similar phenomena for coherent light, is solid-state physics and high-energy physics. (author)

  12. Gross properties of nuclei and nuclear excitations

    International Nuclear Information System (INIS)

    Feldmeier, H.

    1991-01-01

    These proceedings contain the articles presented at the named workshop. They deal with nuclear multifragmentation, heavy ion reaction kinetics, breakup and transfer processes in heavy ion reactions, the production of hypernuclei, nuclear structure in the framework of the quark model and QCD, and particle production in nuclear reactions. (HSI)

  13. Collective excitations in unconventional superconductors and superfluids

    CERN Document Server

    Brusov, Peter

    2009-01-01

    This is the first monograph that strives to give a complete and detailed description of the collective modes (CMs) in unconventional superfluids and superconductors (UCSF&SC). Using the most powerful method of modern theoretical physics - the path (functional) integral technique - authors build the three- and two-dimensional models for s -, p - and d -wave pairing in neutral as well as in charged Fermi-systems, models of superfluid Bose-systems and Fermi-Bose-mixtures. Within these models they study the collective properties of such systems as superfluid 3 He, superfluid 4 He, superfluid 3 He-

  14. Creating collective many-body states with highly excited atoms

    International Nuclear Information System (INIS)

    Olmos, B.; Gonzalez-Ferez, R.; Lesanovsky, I.

    2010-01-01

    The collective excitation of a gas of highly excited atoms confined to a large spacing ring lattice is studied, where the ground and the excited states are resonantly coupled via a laser field. Attention is focused on the regime where the interaction between the highly excited atoms is very weak in comparison to the Rabi frequency of the laser. In this case, the many-body excitations of the system can be expressed in terms of free spinless fermions. The complex many-particle states arising in this regime are characterized and their properties, for example their correlation functions, are studied. Additional investigation into how some of these many-particle states can actually be experimentally accessed by a temporal variation of the laser parameters is performed.

  15. Gross properties of nuclei and nuclear excitations

    International Nuclear Information System (INIS)

    Feldmeier, H.

    1986-01-01

    These proceedings contain the invited and contributed papers presented at the named workshop. They deal with special topics in high- and intermediate-energy nuclear physics. Especially considered are the quark-gluon plasma, ultrarelativistic heavy ion reactions, and the application of QCD to nuclear structure calculations. (HSI)

  16. Gross properties of nuclei and nuclear excitations

    International Nuclear Information System (INIS)

    Feldmeier, H.

    1988-01-01

    These proceedings contain the articles presented at the named workshop. They are concerned with the application of the results from high-energy physics to nuclear structure calculations, thermodynamics of nuclear matter, and kinetics of heavy ion reactions with special regard to relativistic processes. (HSI)

  17. Statistical density of nuclear excited states

    Directory of Open Access Journals (Sweden)

    V. M. Kolomietz

    2015-10-01

    Full Text Available A semi-classical approximation is applied to the calculations of single-particle and statistical level densities in excited nuclei. Landau's conception of quasi-particles with the nucleon effective mass m* < m is used. The approach provides the correct description of the continuum contribution to the level density for realistic finite-depth potentials. It is shown that the continuum states does not affect significantly the thermodynamic calculations for sufficiently small temperatures T ≤ 1 MeV but reduce strongly the results for the excitation energy at high temperatures. By use of standard Woods - Saxon potential and nucleon effective mass m* = 0.7m the A-dependency of the statistical level density parameter K was evaluated in a good qualitative agreement with experimental data.

  18. Measurement of nuclear potentials from fusion excitation functions

    International Nuclear Information System (INIS)

    Huizenga, J.R.; Birkelund, J.R.

    1984-01-01

    The basis for measuring nuclear potentials from fusion excitation functions at energies above barrier is reviewed. It is argued that because of experimental and conceptual problems fusion excitation functions at high energies cannot lead to model independent measurements of internuclear potential at small separations. The Al 27 + Ne 20 reaction previously analyzed by others is used as an example of problems arising from the inability to distinguish complete and incomplete fusion in experimental data

  19. Simulation of Collective Excitations in Long Josephson Junction Stacks

    Science.gov (United States)

    Rahmonov, Ilhom; Shukrinov, Yury; Atanasova, Pavlina; Zemlyanaya, Elena; Streltsova, Oksana; Zuev, Maxim; Plecenik, Andrej; Irie, Akinobu

    2018-02-01

    The phase dynamics of a stack of long Josephson junctions has been studied. Both inductive and capacitive couplings between Josephson junctions have been taken into account in the calculations. The IV-curve, the dependence on the bias current of the radiation power and dynamics of each JJs of the stack have been investigated. The coexistence of the charge traveling wave and fluxon states has been observed. This state can be considered as a new collective excitation in the system of coupled Josephson junctions. We demonstrate that the observed collective excitation leads to the decrease of radiation power from the system.

  20. Individual and collective excitations in the superdeformed nuclei of the 190 mass region; Excitations individuelles et collectives dans les noyaux superdeformes de la region de masse 190

    Energy Technology Data Exchange (ETDEWEB)

    Bouneau, Sandra [Inst. de Physique Nucleaire, Paris-11 Univ., 91 - Orsay (France)

    1997-04-11

    This work aims at the study of different excitation modes, individual and collective, in superdeformed (SD) nuclei in the mass 190 region. The study of {sup 193}Tl and {sup 195,196,197}Bi SD nuclei brought information concerning individual excitation around the proton and neutron SD gaps Z = 80 - 82 and N = 112. Also, the study of the nucleus {sup 196}Pb revealed excited SD states built on collective vibrations. Concerning the isotope {sup 193}Tl, magnetic property analysis has been performed and allowed us to identify the proton intruder orbital {pi}i{sub 13/2} on which the two known SD the bands of the nucleus are build. It was possible to separate experimentally the relative contribution of proton and neutron pairing to the dynamic moment of inertia. Several {gamma} transition of high energy (about 3 MeV) linking SD states to normal deformed states (ND) and three new SD bands have been found in this nucleus. These SD bands have been interpreted in terms of individual excitations of the single proton on different orbitals identified above the proton SD gap Z = 80. An interaction between the states of two excited SD band have been observed and its strength measured. All these results (gyromagnetic factor, the role of nuclear pairing, excitation energy of the SD well, the interaction between two orbitals) represent information of theoretical interest. In each isotope {sup 195-197}Bi, one SD band has been discovered. They have been also interpreted in terms of individual excitation implying the same proton state. The study of this nuclei brought the first experimental proof that the superdeformation phenomenon persists above the shell closure Z = 82. In {sup 196}Pb nucleus a new excited SD band has been discovered. Observations are mentioned suggesting that we have to consider excitations different from those based on individual ones. An interpretation based on vibrational modes can explain both the low energy measured of the excited states in respect with the SD

  1. Study of magnetic moments of nuclear excited states at TRISTAN

    International Nuclear Information System (INIS)

    Hill, J.C.; Wohn, F.K.; Wolf, A.; Berant, Z.; Gill, R.L.; Kruse, H.

    1984-01-01

    Measurement of the static magnetic dipole moments of nuclear excited states are of interest since they reveal information on nuclear structure not available by other means. A system has been constructed at the TRISTAN separator to measure magnetic dipole moments of excited states in neutron-rich nuclei using the method of perturbed angular correlations (PAC). High magnetic fields are not available through the use of a superconducting magnet. The capability of the TRISTAN system is discussed and the PAC measuring apparatus is described. Final results from recent g factor measurements at TRISTAN on 4 + states in the N = 82 isotones are discussed in some detail. Studies in progress are briefly outlined

  2. Nuclear excitations and reaction mechanisms: Progress report

    International Nuclear Information System (INIS)

    Fallieros, S.; Levin, F.S.

    1988-01-01

    This report describes activities of the Nuclear Theory Group at Brown University during the period 1 August 1987-31 July 1988, under Grant FG02-87ER40334. Completed and on-going research includes various theoretical and numerical studies on: parity non-conserving interactions in a relativistic system, processes involving virtual photons and real photons, deuteron-nucleus and neutron-deuteron collisions systems, and muon-catalyzed fusion

  3. Nuclear structure at high excitation energies

    Indian Academy of Sciences (India)

    convention of 7) implying a non-collective rotation about the axis of symmetry. From these discussions it is clear that a detailed investigation of the shape evolution of hot, and highly spinning nuclei employing a theory beyond mean field which accounts for thermal fluctuations of the shape degrees of freedom is called for.

  4. Atomic collisions involving C60 and collective excitation

    Science.gov (United States)

    Tribedi, L. C.; Kelkar, A. H.

    2011-12-01

    Here we review and discuss some of our recent investigations on collective excitation in a free C60 molecule and its influence on the atomic collisions. In particular, emphasis has been given for collisions with fast highly charged ions. It is demonstrated, from the charge-state-dependence studies of recoil-ion spectra, that the plasmon excitation plays a dominant role in the single and double ionization process. The observed linear charge-state-dependence is in contrast to the expected behavior predicted by ion-atom collisions models. This behavior was observed for different projectiles and at different energies. The time-of-flight recoil-ion mass spectroscopy experiments involve 1-5 MeV/u C, O, F and Si ion beams with different charge states, ranging between 4+ and 14+. In addition, the influence of the collective excitation on the electron capture process was also investigated. The wake-field induced Stark-mixing and splitting of sub-levels of projectile-ions following electron capture from C60 carries signature of the collective plasmon excitation. For the electron capture studies X-ray spectroscopic technique was used for collisions with bare and dressed S and Cl ion beams. The results on the TOF data on fullerene target obtained in last few years will be summarized.

  5. Collective excitability in a mesoscopic neuronal model of epileptic activity

    Science.gov (United States)

    Jedynak, Maciej; Pons, Antonio J.; Garcia-Ojalvo, Jordi

    2018-01-01

    At the mesoscopic scale, the brain can be understood as a collection of interacting neuronal oscillators, but the extent to which its sustained activity is due to coupling among brain areas is still unclear. Here we address this issue in a simplified situation by examining the effect of coupling between two cortical columns described via Jansen-Rit neural mass models. Our results show that coupling between the two neuronal populations gives rise to stochastic initiations of sustained collective activity, which can be interpreted as epileptic events. For large enough coupling strengths, termination of these events results mainly from the emergence of synchronization between the columns, and thus it is controlled by coupling instead of noise. Stochastic triggering and noise-independent durations are characteristic of excitable dynamics, and thus we interpret our results in terms of collective excitability.

  6. Search for dibaryonic de-excitations in relativistic nuclear reactions

    International Nuclear Information System (INIS)

    Besliu, C.; Popa, V.; Popa, L.; Topor Pop, V.

    1993-08-01

    Some odd characteristics are observed in the single particle distributions obtained from He + Li interactions at 4.5AGeV/c momenta which are explained as the manifestation of a new mechanism of strangeness production via dibaryonic de-excitations. A signature of the formation of hadronic and baryonic clusters is also reported. The di- pionic signals of the dibaryonic orbital de- excitations are analyzed in the frame of the MIT -bag Model and a Monte Carlo simulation. The role played by the dibaryonic resonances in relativistic nuclear collisions could be a significant one. (author). 29 refs, 7 figs

  7. Collective spin wave and phonon excitations in ferromagnetic organic polymers

    International Nuclear Information System (INIS)

    Leong, Jit-Liang; Sun, Shih-Jye

    2013-01-01

    We proposed a model to investigate the properties of a conductive and ferromagnetic organic-polymer (OCP), which contains two collective excitations—spin wave and phonon—competing with each other; namely, the spin wave excitation accompanies the electron–phonon (e–ph) interactions in the conductive and ferromagnetic OCP. The ferromagnetism of the OCP is induced from the conductive carriers which couple with the phonon to become polarons. Due to the competition between both excitations, the Curie temperature (T C ) is sensitively suppressed by the e–ph interaction. In addition, an optimal T C with a small e–ph interaction exists in a specific density of conduction carrier, yet is contrary to the large e–ph interaction case. Furthermore, the dimerization, i.e. the atomic displacement induced from the e–ph interactions, increases with the strength of the e–ph interaction and decreases upon reaching the maximum dimerization. (paper)

  8. Quantum self-organization and nuclear collectivities

    Science.gov (United States)

    Otsuka, T.; Tsunoda, Y.; Togashi, T.; Shimizu, N.; Abe, T.

    2018-02-01

    The quantum self-organization is introduced as one of the major underlying mechanisms of the quantum many-body systems. In the case of atomic nuclei as an example, two types of the motion of nucleons, single-particle states and collective modes, dominate the structure of the nucleus. The outcome of the collective mode is determined basically by the balance between the effect of the mode-driving force (e.g., quadrupole force for the ellipsoidal deformation) and the resistance power against it. The single-particle energies are one of the sources to produce such resistance power: a coherent collective motion is more hindered by larger gaps between relevant single particle states. Thus, the single-particle state and the collective mode are “enemies” each other. However, the nuclear forces are demonstrated to be rich enough so as to enhance relevant collective mode by reducing the resistance power by changing singleparticle energies for each eigenstate through monopole interactions. This will be verified with the concrete example taken from Zr isotopes. Thus, when the quantum self-organization occurs, single-particle energies can be self-organized, being enhanced by (i) two quantum liquids, e.g., protons and neutrons, (ii) two major force components, e.g., quadrupole interaction (to drive collective mode) and monopole interaction (to control resistance). In other words, atomic nuclei are not necessarily like simple rigid vases containing almost free nucleons, in contrast to the naïve Fermi liquid picture. Type II shell evolution is considered to be a simple visible case involving excitations across a (sub)magic gap. The quantum self-organization becomes more important in heavier nuclei where the number of active orbits and the number of active nucleons are larger. The quantum self-organization is a general phenomenon, and is expected to be found in other quantum systems.

  9. Collective Excitations in Liquid Hydrogen Observed by Coherent Neutron Scattering

    DEFF Research Database (Denmark)

    da Costa Carneiro, Kim; Nielsen, M.; McTague, J. P.

    1973-01-01

    Coherent scattering of neutrons by liquid parahydrogen shows the existence of well-defined collective excitations in this liquid. Qualitative similarity with the scattering from liquid helium is found. Furthermore, in the range of observed wave vectors, 0.7 Å-1 ≤κ≤3.1 Å-1, extending from the firs...... through the third Brillouin zones in the solid, S(κ,ω) is remarkably similar to the scattering law expected from a polycrystal. For κ≤2.3 Å-1 the observed spectra satisfy the one-phonon sum rule with mean square displacement 〈u2〉=1.0 Å2....

  10. Thermodynamics of excited nuclei and nuclear level densities

    International Nuclear Information System (INIS)

    Ramamurthy, V.S.

    1977-01-01

    A review has been made of the different approaches that are being used for a theoretical calculation of nuclear level densities. It is pointed out that while the numerical calculations based on the partition function approach and shell model single particle level schemes have shed important insight into the influence of nuclear shell effects on level densities and its excitation energy dependence and have brought out the inadequacy of the conventional Bethe Formula, these calculations are yet to reach a level where they can be directly used for quantitative comparisons. Some of the important drawbacks of the numerical calculations are also discussed. In this context, a new semi-empirical level density formula is described which while retaining the simplicity of analytical formulae, takes into account nuclear shell effects in a more realistic manner. (author)

  11. Theory of nuclear excitation by electron capture for heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Gagyi-Palffy, A.

    2006-07-01

    The resonant process of nuclear excitation by electron capture (NEEC) in collisions involving highly-charged ions has been investigated theoretically. NEEC is a rare recombination process in which a free electron is captured into a bound shell of an ion with the simultaneous excitation of the nucleus. Total cross sections for NEEC followed by the radiative decay of the excited nucleus are presented for various collision systems. The possibility to observe the NEEC in scattering experiments with trapped or stored ions was discussed focusing on the cases with the largest calculated resonance strength. As the photons emitted in different channels of the electron recombination process are indistinguishable in the total cross section, the interference between NEEC followed by the radiative decay of the nucleus and radiative recombination was investigated. The angular distribution of the emitted photons in the recombination process provides means to discern the two processes. Angular differential cross sections for the emitted photons in the case of E2 nuclear transitions were presented for several heavy elements. (orig.)

  12. New trends in nuclear collective dynamics

    International Nuclear Information System (INIS)

    Abe, Yasuhisa; Horiuchi, Hisashi; Matsuyanagi, Kenichi

    1992-01-01

    New Trends in Nuclear Collective Dynamics comprises reviews by well-known researchers from international centers of nuclear physics. This overview of recent advances concentrates on - order amd chaos in finite quantum systems - dissipation in heavy-ion collions - collective motion in warm nuclei - time-dependent mean-field theory with collision terms - nuclear fission and multi-dimensional tunneling - large scale collective motion see hints under the relevent topics. (orig.) With 90 figs

  13. Collective excitations of holographic quantum liquids in a magnetic field

    Science.gov (United States)

    Brattan, Daniel K.; Davison, Richard A.; Gentle, Simon A.; O'Bannon, Andy

    2012-11-01

    We use holography to study {N} = 4 supersymmetric SU( N c) Yang-Mills theory in the large- N c and large-coupling limits coupled to a number N f ≪ N c of ( n + 1)-dimensional massless supersymmetric hypermultiplets in the fundamental representation of SU(Nc), with n = 2, 3. We introduce a temperature T, a baryon number chemical potential μ, and a baryon number magnetic field B, and work in a regime with μ ≫ T, √{B} . We study the collective excitations of these holographic quantum liquids by computing the poles in the retarded Green's function of the baryon number charge density operator and the associated peaks in the spectral function. We focus on the evolution of the collective excitations as we increase the frequency relative to T , i.e. the hydrodynamic/collisionless crossover. We find that for all B, at low frequencies the tallest peak in the spectral function is associated with hydrodynamic charge diffusion. At high frequencies the tallest peak is associated with a sound mode similar to the zero sound mode in the collisionless regime of a Landau Fermi liquid. The sound mode has a gap proportional to B, and as a result for intermediate frequencies and for B sufficiently large compared to T the spectral weight is strongly suppressed. We find that the hydrodynamic/collisionless crossover occurs at a frequency that is approximately B-independent.

  14. Collective excitations in an interacting boson gas beyond Bogoliubov theory

    Science.gov (United States)

    Ferrari, Loris

    2017-05-01

    In a gas of N interacting bosons, the Hamiltonian Hc, obtained by dropping all the interaction terms between free bosons with moment ℏk ≠ 0 , is diagonalized exactly. The resulting eigenstates | S , k , η 〉 depend on two discrete indices S , η = 0 , 1 , … , where η numerates the quasiphonons carrying a moment ℏk , responsible for transport or dissipation processes. S, in turn, numerates a ladder of 'vacua' | S , k , 0 〉 , with increasing equispaced energies, formed by boson pairs with opposite moment. Passing from one vacuum to another (S → S ± 1), results from creation/annihilation of new momentless collective excitations, that we call pseudobosons. Exact quasiphonons originate from one of the vacua by 'creating' an asymmetry in the number of opposite moment bosons. The well known Bogoliubov collective excitations (CEs) are shown to coincide with the exact eigenstates | 0 , k , η 〉 , i.e. with the quasiphonons (QPs) created from the lowest-level vacuum (S=0). All this is discussed, in view of existing or future experimental observations of the pseudobosons (PBs), a sort of bosonic Cooper pairs, which are the main factor of novelty beyond Bogoliubov theory.

  15. Search for collective excitations in nanoparticles of biological origin

    International Nuclear Information System (INIS)

    Papp, T.; Hunyadi, M.; Gacsi, Z.; Toth, J.; Varga, D.

    2009-01-01

    Complete text of publication follows. Nanoparticles of biological origin are abundant in nature. One might even consider searching for them in extraterrestrial objects as a remnant of life, and a fingerprint of the existence of primitive life forms billions of years ago. It is also intriguing to consider the potentiality that some of the bacteria use very scarcely available elements for the internal (detoxication) and external (dissimilatory reduction) production of nanocrystals, for example like Te(0). Developing a breathing process based on a rare earth element, certainly is a stretch on the evolution idea. Turning the reasoning around, one can speculate that such primitive life forms have evolved in a very different environment, where the base elements of their make up were abundant, which is not the case on Earth. The late Prof. Terry Beveridge of University of Guelph, ON, Canada raised the idea on a speculative level, that such a characteristic biosignature imposed on a trace element like selenium may conceivably be useful in the search for evidence of extinct microbial communities in sedimentary deposits of extraterrestrial origin (i.e., Mars). These are challenging ideas, but there are potentially imminent benefits of using microorganisms to mass produce nanoparticles. Currently there is technical interest in tellurium with the aim of developing solar cells that have high efficiency to convert sunlight into electrical current. We are involved in photovoltaic technology research, and are developing CdTe detectors for X-ray detection. We have recently observed giant resonances in scintillators, and with doping the CdTe could be turned into PET (Positron Emission Tomography) detector material. Therefore we have interest in the electro-optical properties of Te and Se. Our study of collective excitations and giant resonances in X-ray and nuclear radiation detectors has initiated new models and approaches in detector research. It is well established that giant

  16. New laser-driven nuclear excitation studies. Concepts and proposals

    International Nuclear Information System (INIS)

    Drska, L.; Hanus, V.; Sinor, M.

    2010-01-01

    Complete text of publication follows. There has been a great interest in the processes of nuclear excitation and triggering in high-parameter laser-produced plasmas in recent years. A series of papers devoted to the theory of this event has been published. Several experiments have already been attempted to study the excitation of the lowest nuclear levels of medium / high-Z nuclides (Ta 181, U 235 etc.), all the same unsuccessful or inconclusive. In the first part of this paper, the situation will be overviewed and analysis of the reasons of this unsatisfactory state of affairs will be accomplished. Prospects of the possible solving of the problem by using novel / projected laser facilities (esp. LIL / PETAL, XFEL, ELI-Phase) will be outlined. Potential of the future ELI Beam Facility in the Czech Republic in this area will be stressed. In the second part, some proposals for the excitation and triggering studies using combined high-power and high-intensity LIL / PETAL system (2012) with multi-kilojoule and multi-petawatt parameters will be discussed. Results of preliminary simulations supporting the thinking about potential projects will be shown and conditions essential for meaningful effort in this area will be analyzed. Problems of realistic simulations of such experiments will be addressed. Completely novel chances for the excitation / triggering studies would be started by constructed / projected facilities XFEL (coherent X-rays ∼ 12 keV, 2014) and ELI (multi-petawatt Phase 1, 2015). Application of intense / coherent high-energy X-rays and / or intense electron / ion beams allows new experimental schemes, extends the range of nuclides to be studied and (maybe) will enable to test some new triggering methods. In the last part of the presentation some possibilities in point (esp. for ELI Beamlines), will be drawn up. Acknowledgements. This research has been supported by the Research Program no. 6840770022 of the Ministry of Education, Youth and Sports of the

  17. No evidence of reduced collectivity in Coulomb-excited Sn isotopes

    Science.gov (United States)

    Kumar, R.; Saxena, M.; Doornenbal, P.; Jhingan, A.; Banerjee, A.; Bhowmik, R. K.; Dutt, S.; Garg, R.; Joshi, C.; Mishra, V.; Napiorkowski, P. J.; Prajapati, S.; Söderström, P.-A.; Kumar, N.; Wollersheim, H.-J.

    2017-11-01

    In a series of Coulomb excitation experiments the first excited 2+ states in semimagic Sn 112 ,116 ,118 ,120 ,122 ,124 isotopes were excited using a 58Ni beam at safe Coulomb energy. The B (E 2 ; 0+→2+) values were determined with high precision (˜3 %) relative to 58Ni projectile excitation. These results disagree with previously reported B (E 2 ↑) values [A. Jungclaus et al., Phys. Lett. B 695, 110 (2011)., 10.1016/j.physletb.2010.11.012] extracted from Doppler-shift attenuation lifetime measurements, whereas the reported mass dependence of B (E 2 ↑) values is very similar to a recent Coulomb excitation study [J. M. Allmond et al., Phys. Rev. C 92, 041303(R) (2015), 10.1103/PhysRevC.92.041303]. The stable Sn isotopes, key nuclei in nuclear structure, show no evidence of reduced collectivity and we, thus, reconfirm the nonsymmetric behavior of reduced transition probabilities with respect to the midshell A =116 .

  18. International conference: Features of nuclear excitation states and mechanisms of nuclear reactions. 51. Meeting on nuclear spectroscopy and nuclear structure. The book of abstracts

    International Nuclear Information System (INIS)

    2001-01-01

    Results of the LI Meeting on Nuclear Spectroscopy and Nuclear Structure are presented. Properties of excited states of atomic nuclei and mechanisms of nuclear reactions are considered. Studies on the theory of nucleus and fundamental interactions pertinent to experimental study of nuclei properties and mechanisms of nuclear reactions, technique and methods of experiment, application of nuclear-physical method, are provided [ru

  19. Pairing and deformation effects in nuclear excitation spectra

    Energy Technology Data Exchange (ETDEWEB)

    Repko, A. [Slovak Academy of Sciences, Institute of Physics, Bratislava (Slovakia); Kvasil, J. [Charles University, Institute of Particle and Nuclear Physics, Prague (Czech Republic); Nesterenko, V.O. [Joint Institute for Nuclear Research, Laboratory of Theoretical Physics, Dubna (Russian Federation); State University ' ' Dubna' ' , Dubna (Russian Federation); Reinhard, P.G. [Universitaet Erlangen, Institut fuer Theoretische Physik II, Erlangen (Germany)

    2017-11-15

    We investigate effects of pairing and of quadrupole deformation on two sorts of nuclear excitations, γ-vibrational K{sup π} = 2{sup +} states and dipole resonances (isovector dipole, pygmy, compression, toroidal). The analysis is performed within the quasiparticle random phase approximation (QRPA) based on the Skyrme energy functional using the Skyrme parametrization SLy6. Particular attention is paid to i) the role of the particle-particle (pp) channel in the residual interaction of QRPA, ii) comparison of volume pairing (VP) and surface pairing (SP), iii) peculiarities of deformation splitting in the various resonances. We find that the impact of the pp-channel on the considered excitations is negligible. This conclusion applies also to any other excitation except for the K{sup π} = 0{sup +} states. Furthermore, the difference between VP and SP is found small (with exception of peak height in the toroidal mode). In the low-energy isovector dipole (pygmy) and isoscalar toroidal modes, the branch K{sup π} = 1{sup -} is shown to dominate over the K{sup π} = 0{sup -} one in the range of excitation energy E < 8-10 MeV. The effect becomes impressive for the toroidal resonance whose low-energy part is concentrated in a high peak of almost pure K{sup π} = 1{sup -} nature. This peculiarity may be used as a fingerprint of the toroidal mode in future experiments. The interplay between pygmy, toroidal and compression resonances is discussed, the interpretation of the observed isoscalar giant dipole resonance is partly revised. (orig.)

  20. Evolution of collectivity in the 78Ni region: Coulomb excitation of 74Ni at intermediate energies.

    Directory of Open Access Journals (Sweden)

    Marchi T.

    2014-03-01

    Full Text Available The study of the collective properties of nuclear excitations far from stability provides information about the shell structure at extreme conditions. Spectroscopic observables such as the energy or the transition probabilities of the lowest states, in nuclei with large neutron excess, allow to probe the density and isospin dependence of the effective interaction. Indeed, it was recently shown that tensor and three-body forces play an important role in breaking and creating magic numbers. Emblematic is the case of the evolution of the Ni isotopic chain where several features showed up moving from the most neutron rich stable isotope (64Ni towards the 78Ni nucleus where the large neutron excess coincides with a double shell closure. In this framework, we have recently performed an experiment with the goal to extract the B(E2; 0+ → 2+ value for the 74Ni nucleus in an intermediate-energy Coulomb excitation experiment: preliminary results are discussed.

  1. Detection of Actinides via Nuclear Isomer De-Excitation

    Energy Technology Data Exchange (ETDEWEB)

    Francy, Christopher J. [Oregon State Univ., Corvallis, OR (United States)

    2009-07-01

    This dissertation discusses a data collection experiment within the Actinide Isomer Identification project (AID). The AID project is the investigation of an active interrogation technique that utilizes nuclear isomer production, with the goal of assisting in the interdiction of illicit nuclear materials. In an attempt to find and characterize isomers belonging to 235U and its fission fragments, a 232Th target was bombarded with a monoenergetic 6Li ion beam, operating at 45 MeV.

  2. Isospin effects on collective nuclear dynamics

    CERN Document Server

    Di Toro, M; Baran, V; Larionov, A B

    1999-01-01

    We suggest several ways to study properties of the symmetry term in the nuclear equation of state, EOS, from collective modes in beta-unstable nuclei. After a general discussion on compressibility and saturation density in asymmetric nuclear matter we show some predictions on the collective response based on the solution of generalized Landau dispersion relations. Isoscalar-isovector coupling, disappearance of collectivity and possibility of new instabilities in low and high density regions are discussed with accent on their relation to the symmetry term of effective forces. The onset of chemical plus mechanical instabilities in a dilute asymmetric nuclear matter is discussed with reference to new features in fragmentation reactions.

  3. Collective excitations and low temperature transport properties of bismuth

    Energy Technology Data Exchange (ETDEWEB)

    Chudzinski, Piotr; Giamarchi, Thierry [DPMC-MaNEP, University of Geneva (Switzerland)

    2011-07-01

    We examine the influence of collective excitations on several transport coefficients (conductivity, magneto-optical conductivity, Nernst effect) for semimetal, bismuth. A longstanding problem of the transport coefficients in this material is the fact that their amplitude and temperature dependences do not obey naive Fermi liquid expectations. For the conductivity, we show that at high temperatures Baber scattering is able to explain quantitatively the DC resistivity experiments, while at low temperatures many-body effects need to be introduced to explain qualitative deviations from the standard T{sup 2} behavior. An atypical feature in magneto-optical conductivity is predicted. The Nernst effect in bismuth was recently the subject of several contradictory theoretical studies. We show that a plasmon physics allows to get a coherent picture and leads to very large values of the Nernst signal. We use two complementary methods- Feynmann diagrams and field theory (Hubbard-Stratonovich transformation). These methods, which go beyond the standard RPA study, allow to set a limit to the validity of our model and to make contact with the other family of semimetals, 1T-TiSe{sub 2}, also subject of recent experimental interest. To complete the discussion of semimetals, we also study the case of graphite.

  4. New features of nuclear excitation by {alpha} particles scattering; Nouveaux aspects de l'excitation nucleaire par diffusion de particules {alpha}

    Energy Technology Data Exchange (ETDEWEB)

    Saudinos, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-07-01

    Inelastic scattering of medium energy a particles by nuclei is known to excite preferentially levels of collective character. We have studied the scattering of isotopically enriched targets of Ca, Fe, Ni, Cu, Zn. In part I, we discuss the theoretical features of the interaction. In part II, we describe the experimental procedure. Results are presented and analysed in part III. {alpha} particles scattering by Ca{sup 40} is showed to excite preferentially odd parity levels. In odd nuclei we have observed multiplets due to the coupling of the odd nucleon with the even-even core vibrations. For even-even nuclei, a few levels are excited with lower cross-sections between the well-known first 2{sup +} and 3{sup -} states. Some could be members of the two phonon quadrupole excitation and involve a double nuclear excitation process. (author) [French] On sait que la diffusion inelastique des particules alpha de moyenne energie excite preferentiellement des niveaux de caractere collectif. Nous avons etudie la diffusion des particules alpha de 44 MeV du cyclotron de Saclay par des isotopes separes de Ca, Fe, Ni, Cu, Zn. Dans la premiere partie nous exposons les theories de cette interaction. Dans la seconde nous decrivons le systeme experimental. Les resultats sont donnes dans la troisieme partie. Nous montrons que les niveaux excites preferentiellement pour {sup 40}Ca par diffusion ({alpha},{alpha}') sont de parite negative. Dans les noyaux pair-impair nous avons observe des multiplets dus au couplage du nucleon celibataire avec les vibrations du coeur pair-pair. Pour les noyaux pair-pair nous avons pu etudier entre le premier niveau 2{sup +} et le niveau 3{sup -} deja bien connus certains etats plus faiblement excites. Il semble qu'ils sont dus a une excitation quadrupolaire a deux phonons et impliquent un processus de double excitation nucleaire. (auteur)

  5. Collective dose commitments from nuclear power programmes

    International Nuclear Information System (INIS)

    Beninson, D.

    1977-01-01

    The concepts of collective dose and collective dose commitment are discussed, particularly regarding their use to compare the relative importance of the exposure from several radiation sources and to predict future annual doses from a continuing practice. The collective dose commitment contributions from occupational exposure and population exposure due to the different components of the nuclear power fuel cycle are evaluated. A special discussion is devoted to exposures delivered over a very long time by released radionuclides of long half-lives and to the use of the incomplete collective dose commitment. The maximum future annual ''per caput'' doses from present and projected nuclear power programmes are estimated

  6. Quantum dissipation and decoherence of collective excitations in metallic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Weick, G.

    2006-09-22

    The treatment of the surface plasmon as a quantum particle provides a model system for the study of decoherence and quantum dissipation in confined nanoscopic systems, where the role of the electronic correlations is preponderant. Throughout this work we treat the metallic nanoparticle in the jellium approximation where the ionic structure is replaced by a continuous and homogeneous positive charge. The external laser field puts the center of mass into a coherent superposition of its ground and first excited state and thus creates a surface plasmon. The coupling between the center of mass and the relative coordinates causes decoherence and dissipation of this collective excitation. We have developed a theoretical formalism well adapted to the study of this dissipation, which is the reduced-density-matrix formalism. There are mainly two parameters which govern the surface plasmon dynamics: the decay rate of the plasmon, and the resonance frequency. For sizes smaller than 1 nm, presents oscillations as a function of the size. By means of a semiclassical formalism using Gutzwiller's trace formula for the density of states, we have shown that those oscillations are due to the correlations of the density of states of the particles and holes in the nanoparticle. If one considers a noble-metal nanoparticle in an inert matrix, we have shown that a naive application of the Kubo formula for the surface plasmon linewidth fails to reproduce the TDLDA numerical results, which are however consistent with experimental results. We have modified the Kubo theory in order to solve this discrepancy. We have shown, by extending our semiclassical theory to the nonlinear case, that the double plasmon is indeed well defined. We have calculated the lifetime of the double plasmon associated to this second-order effect. In addition to the width, we have also addressed the value of the resonance frequency. The classical electromagnetic Mie theory gives for the resonance frequency of the

  7. Collective excitations of a Bose-Einstein condensate in a magnetic trap

    NARCIS (Netherlands)

    Mewes, M.O.; Andrews, M.R.; van Druten, N.J.; Kurn, D.M.; Durfee, D.S.; Townsend, C.G.; Ketterle, W.

    1996-01-01

    Collective excitations of a dilute Bose condensate have been observed. These excitations are analogous to phonons in superfluid helium. Bose condensates were created by evaporatively cooling magnetically trapped sodium atoms. Excitations were induced by a modulation of the trapping potential, and

  8. Nuclear Excitation by Electronic Transition of U-235

    Energy Technology Data Exchange (ETDEWEB)

    Chodash, Perry Adam [Univ. of California, Berkeley, CA (United States)

    2015-07-14

    Nuclear excitation by electronic transition (NEET) is a rare nuclear excitation that is theorized to occur in numerous isotopes. One isotope in particular, 235U, has been studied several times over the past 40 years and NEET of 235U has never been conclusively observed. These past experiments generated con icting results with some experiments claiming to observe NEET of 235U and others setting limits for the NEET rate. This dissertation discusses the latest attempt to measure NEET of 235U. If NEET of 235U were to occur, 235mU would be created. 235mU decays by internal conversion with a decay energy of 76 eV and a half-life of 26 minutes. A pulsed Nd:YAG laser operating at 1064 nm with a pulse energy of 789 mJ and a pulse width of 9 ns was used to generate a uranium plasma. The plasma was captured on a catcher plate and electrons emitted from the catcher plate were accelerated and focused onto a microchannel plate detector. A decay of 26 minutes would suggest the creation of 235mU and the possibility that NEET occurred. However, measurements performed using a variety of uranium targets spanning depleted uranium up to 99.4% enriched uranium did not observe a 26 minute decay. Numerous other decays were observed with half-lives ranging from minutes up to hundreds of minutes. While NEET of 235U was not observed during this experiment, an upper limit for the NEET rate of 235U was determined. In addition, explanations for the con icting results from previous experiments are given. Based on the results of this experiment and the previous experiments looking for NEET of 235U, it is likely that NEET of 235U has never been observed.

  9. Collective 0+, 1+ and 2+ excitations in rotating nuclei

    International Nuclear Information System (INIS)

    Balbutsev, E.B.; Piperova, J.

    1988-01-01

    The energies and B(Eγ) factors of the isoscalar and isovector 0 + and 2 + resonances are calculated with Skyrme interaction. A satisfactory agreement with experimental data is obtained. It is shown that in rotating nuclei the 2 + excitations split into five branches and also 5 low-lying excitations appear. Two of these low-lying modes are angular resonances and the theory reproduces their energies and B(M1) factors. The experimentally observed splitting of giant monopole resonance in deformed nuclei is confirmed. 34 refs.; 10 figs.; 1 tab

  10. A Neutron Scattering Study of Collective Excitations in Superfluid Helium

    DEFF Research Database (Denmark)

    Graf, E. H.; Minkiewicz, V. J.; Bjerrum Møller, Hans

    1974-01-01

    Extensive inelastic-neutron-scattering experiments have been performed on superfluid helium over a wide range of energy and momentum transfers. A high-resolution study has been made of the pressure dependence of the single-excitation scattering at the first maximum of the dispersion curve over...... of the multiexcitation scattering was also studied. It is shown that the multiphonon spectrum of a simple Debye solid with the phonon dispersion and single-excitation cross section of superfluid helium qualitatively reproduces these data....

  11. Collective excitations, NMR, and phase transitions in Skyrme Crystals

    NARCIS (Netherlands)

    Côté, R.; MacDonald, A.H.; Brey, L.; Fertig, H.A.; Girvin, S.M.; Stoof, H.T.C.

    1997-01-01

    At Landau level filling factors near ν = 1, quantum Hall ferromagnets form a Skyrme crystal state with quasi-long-range translational and noncollinear magnetic order. We develop an effective low energy theory which explains the presence of magnetic excitations in these systems at energies below the

  12. Coulomb excitation of $^{116}$Te and $^{118}$Te: a study of collectivity above the Z = 50 shell gap

    CERN Multimedia

    Cederkall, J A; Smith, J F; Voulot, D; Rahkila, P J; Darby, I G; Hadinia, B; Grahn, T; Paul, E S; Wadsworth, R; Bree, N C F; Baeck, T M; Julin, R J; Diriken, J V J; Jenkins, D G; Kroell, T; Leske, J; Huyse, M L

    We propose to study the nature and collectivity of low-energy excitations in $^{116}$Te and $^{118}$Te. We aim to measure the transition probability of the 0$^{+}$ $\\rightarrow$ 2$^{+}$ transition by means of Coulomb excitation, employing REX-ISOLDE and MINIBALL. The proposed study probes the systematics of B(E2) values in light Te nuclei, which lie in a region of the nuclear chart where unusual phenomena and evolution of collectivity have been observed. The proposed study will shed light on the role of the residual proton-neutron interactions in the development of collectivity when approaching the N = Z line. This is a resubmission of the P-277 proposal. The suggestions of INTC have been taken into account and the data from the Yale $^{120}$Te study has been included.

  13. Collective hypersonic excitations in strongly multiple scattering colloids.

    Science.gov (United States)

    Still, T; Gantzounis, G; Kiefer, D; Hellmann, G; Sainidou, R; Fytas, G; Stefanou, N

    2011-04-29

    Unprecedented low-dispersion high-frequency acoustic excitations are observed in dense suspensions of elastically hard colloids. The experimental phononic band structure for SiO(2) particles with different sizes and volume fractions is well represented by rigorous full-elastodynamic multiple-scattering calculations. The slow phonons, which do not relate to particle resonances, are localized in the surrounding liquid medium and stem from coherent multiple scattering that becomes strong in the close-packing regime. Such rich phonon-matter interactions in nanostructures, being still unexplored, can open new opportunities in phononics.

  14. The Microscopic Models of Collective Excitations. Present Status and Possible Ways of Improvement

    International Nuclear Information System (INIS)

    Belyaev, S.T.

    1968-01-01

    The paper analyses possible generalizations of the known collective excitation models in the following directions: (a) inclusion of other kinds of interactions, generating new types of oscillations, (b) improvement of the quasiboson approximation. The classification of excitations according to the quantum numbers of correlate pairs provides the basis for the corresponding classification of the elementary interactions generating these excitations. For low excitations the number of important ''generating interactions'' is not large and practically all of them have been tested. A special study is made of the particle-particle channel where ''elementary interactions'' can be introduced without any new parameters, if the hypothesis of gauge invariance of nucleon-nucleon interaction is used. Additional (to usual pairing) interaction in the particle-particle channel generates 0 + -states - ''coherent pairing fluctuation'' — having a uniquely large probability ratio of EO and E2 transitions into the ground band. The experimental identification of such states is of great interest. The necessity to: reject the quasiboson approximation is dictated by the complicated vibrational-rotational structure of experimental nuclear spectra. The main difficulty of their theoretical description is the absence of a consistent microscopic picture of rotational excitations. Only in very special models can the group theory be applied and show how rotation appears in the system of interacting particles. A method worked out by Belyaev and Zelevinsky is considered, which gives the possibility of a microscopic description of rotations. The proposed method includes some aspects of group theory approach that, together with the equations of motion for pair operators,allow the consideration of realistic models in a sufficiently good approximation. The illustration of the method serves to obtain the rotational spectrum for j N configuration with a further generalization on an arbitrary number of

  15. Study of excitation energy dependence of nuclear level density parameter

    International Nuclear Information System (INIS)

    Mohanto, G.; Nayak, B.K.; Saxena, A.

    2016-01-01

    In the present study, we have populated CN by fusion reaction and excitation energy of the intermediate nuclei is determined after first chance α-emission to investigate excitation energy dependence of the NLD parameter. Evaporated neutron spectra were measured following alpha evaporation for obtaining NLD parameter for the reaction 11 B + 197 Au, populating CN 208 Po. This CN after evaporating an α-particle populates intermediate nucleus 204 Pb. The 204 Pb has magic number of Z=82. Our aim is to study the excitation energy dependence of NLD parameter for closed shell nuclei

  16. Tailoring Laser-Generated Plasmas for Efficient Nuclear Excitation by Electron Capture

    Science.gov (United States)

    Wu, Yuanbin; Gunst, Jonas; Keitel, Christoph H.; Pálffy, Adriana

    2018-02-01

    The optimal parameters for nuclear excitation by electron capture in plasma environments generated by the interaction of ultrastrong optical lasers with solid matter are investigated theoretically. As a case study we consider a 4.85 keV nuclear transition starting from the long-lived Mom93 isomer that can lead to the release of the stored 2.4 MeV excitation energy. We find that due to the complex plasma dynamics, the nuclear excitation rate and the actual number of excited nuclei do not reach their maximum at the same laser parameters. The nuclear excitation achievable with a high-power optical laser is up to twelve and up to six orders of magnitude larger than the values predicted for direct resonant and secondary plasma-mediated excitation at the x-ray free electron laser, respectively. Our results show that the experimental observation of the nuclear excitation of Mom93 and the subsequent release of stored energy should be possible at laser facilities available today.

  17. A Microscopic Quantal Model for Nuclear Collective Rotation

    International Nuclear Information System (INIS)

    Gulshani, P.

    2007-01-01

    A microscopic, quantal model to describe nuclear collective rotation in two dimensions is derived from the many-nucleon Schrodinger equation. The Schrodinger equation is transformed to a body-fixed frame to decompose the Hamiltonian into a sum of intrinsic and rotational components plus a Coriolis-centrifugal coupling term. This Hamiltonian (H) is expressed in terms of space-fixed-frame particle coordinates and momenta by using commutator of H with a rotation angle. A unified-rotational-model type wavefunction is used to obtain an intrinsic Schrodinger equation in terms of angular momentum quantum number and two-body operators. A Hartree-Fock mean-field representation of this equation is then obtained and, by means of a unitary transformation, is reduced to a form resembling that of the conventional semi-classical cranking model when exchange terms and intrinsic spurious collective excitation are ignored

  18. Microscopic boson approach to nuclear collective motion

    International Nuclear Information System (INIS)

    Kuchta, R.

    1989-01-01

    A quantum mechanical approach to the maximally decoupled nuclear collective motion is proposed. The essential idea is to transcribe the original shell-model Hamiltonian in terms of boson operators, then to isolate the collective one-boson eigenstates of the mapped Hamiltonian and to perform a canonical transformation which eliminates (up to the two-body terms) the coupling between the collective and noncollective bosons. Unphysical states arising due to the violtion of the Pauli principle in the boson space are identified and removed within a suitable approximation. The method is applied to study the low-lying collective states of nuclei which are successfully described by the exactly solvable multilevel pairing Hamiltonian (Sn, Ni, Pb). 75 refs.; 8 figs

  19. Collective excitations in liquid and glassy 3-methylpentane

    KAUST Repository

    Benassi, Paola

    2015-09-28

    We present a detailed investigation of the terahertz vibrational dynamics of 3-methylpentane performed by means of high-resolution inelastic x-ray scattering (IXS). We probe the dynamics in a large temperature range, which includes the glass, the supercooled liquid, and the liquid phases. The characteristic frequency of the excitations follows a well-defined dispersion curve extending beyond 8nm−1 at all the investigated temperatures, indicating the persistence of a solidlike behavior also in the liquid phase. This implies the existence of a pseudo-Brillouin zone whose size compares surprisingly well with the periodicity inferred from the first sharp diffraction peak in the static structure factor. We show that, in the investigated temperature range, both sizes undergo a variation of about 15%–20%, comparable to that of the average intermolecular distance. We finally show that the IXS sound velocity coincides with the infinite frequency sound velocity previously inferred from visible and ultraviolet Brillouin spectroscopy data. This analysis confirms the role of the shear relaxation processes in determining the variation with frequency of the apparent sound velocity.

  20. Collective, stochastic and nonequilibrium behavior of highly excited hadronic matter

    International Nuclear Information System (INIS)

    Carruthers, P.

    1983-01-01

    We discuss selected problems concerning the dynamic and stochasticc behavior of highly excited matter, particularly the QCD plasma. For the latter we consider the equation of state, kinetics, quasiparticles, flow properties and possible chaos and turbulence. The promise of phase space distribution functions for covariant transport and kinetic theory is stressed. The possibility and implications of a stochastic bag are spelled out. A simplified space-time model of hadronic collisions is pursued, with applications to A-A collisions and other matters. The domain wall between hadronic and plasma phase is of potential importance: its thickness and relation to surface tension are noticed. Finally we reviewed the recently developed stochastic cell model of multiparticle distributions and KNO scaling. This topic leads to the notion that fractal dimensions are involved in a rather general dynamical context. We speculate that various scaling phenomena are independent of the full dynamical structure, depending only on a general stochastic framework having to do with simple maps and strange attractors. 42 references

  1. Preparations for an optical access to the lowest nuclear excitation in {sup 229}Th

    Energy Technology Data Exchange (ETDEWEB)

    Wense, Lars v.d.; Seiferle, Benedict; Thirolf, Peter [Ludwig-Maximilians-Universitaet Muenchen (Germany); Laatiaoui, Mustapha [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH (Germany)

    2014-07-01

    The isomeric lowest excited nuclear level of {sup 229}Th has been indirectly measured to be 7.6±0.5 eV (163±11 nm). In order to improve the accuracy as prerequisite of an all-optical control, {sup 229m}Th is populated via a 2% decay branch in the α decay of {sup 233}U. The Thorium ions are extracted and cooled with the help of a buffer gas stopping cell and an RFQ-cooler. In order to suppress accompanying α decay chain products other than {sup 229}Th, a quadrupole mass spectrometer (QMS) is used, performance and extraction efficiency measurements were performed. Following the QMS, the Thorium isomers will be collected on a 50 μm micro electrode. The decay of these isomers can then be detected using deep UV optics, presently in the phase of preparation and adjustment. Newest results are presented.

  2. Parametric excitation of nuclear spin waves in MnCO3 antiferromagnetic crystals

    International Nuclear Information System (INIS)

    Govorkov, S.A.; Tulin, V.A.

    1976-01-01

    Parametric excitation of nuclear spin waves in the antiferromagnetic crystal MnCO 3 is investigated at 1080 MHz by the parallel pumping technique. Two threshold processes are observed in the experiments. One refers to spin wave excitation in a nuclear magnetic system and the other to excitation of magneto-elastic waves. The post-threshold sample susceptibility in such processes is studied. After the second threshold a very pronounced overheating of the nuclear magnetic system of the sample with respect to the lattice is observed. The nature of these overheating phenomena shows that two magneto-elastic oscillation branches are excited in the second threshold process. The dependence of the threshold field on wave vector is more complicated in a small magnetic field due to magnetization processes in the sample. In a large magnetic field complications are evoked by the magneto-elastic coupling

  3. The Δ excitation in the nuclear-charge longitudinal response

    International Nuclear Information System (INIS)

    Amore, P.; Cenni, R.; Saracco, P.; Genoa Univ., Genoa

    1999-01-01

    The presence of a resonant structure corresponding to the Δ excitation in the longitudinal response to an e.m. probe is investigated. It is shown that many-body effects could significantly increase the relativistic contribution suggested by M. Ericson and coworkers

  4. Coulomb and nuclear excitations of narrow resonances in 17Ne

    Directory of Open Access Journals (Sweden)

    J. Marganiec

    2016-08-01

    Full Text Available New experimental data for dissociation of relativistic 17Ne projectiles incident on targets of lead, carbon, and polyethylene targets at GSI are presented. Special attention is paid to the excitation and decay of narrow resonant states in 17Ne. Distributions of internal energy in the O15+p+p three-body system have been determined together with angular and partial-energy correlations between the decay products in different energy regions. The analysis was done using existing experimental data on 17Ne and its mirror nucleus 17N. The isobaric multiplet mass equation is used for assignment of observed resonances and their spins and parities. A combination of data from the heavy and light targets yielded cross sections and transition probabilities for the Coulomb excitations of the narrow resonant states. The resulting transition probabilities provide information relevant for a better understanding of the 17Ne structure.

  5. Nuclear isovector giant resonances excited by pion single charge exchange

    International Nuclear Information System (INIS)

    King, B.H.

    1993-07-01

    This thesis is an experimental study of isovector giant resonances in light nuclei excited by pion single charge exchange reactions. Giant dipole resonances in light nuclei are known to be highly structured. For the mass 9 and 13 giant dipole resonances, isospin considerations were found to be very important to understanding this structure. by comparing the excitation functions from cross section measurements of the (π + , π 0 ) and (π, π 0 ) inclusive reactions, the authors determined the dominant isospin structure of the analog IVGR's. The comparison was made after decomposing the cross section into resonant and non-resonant components. This decomposition is made in the framework of strong absorption and quasi-free scattering. Measurements in the region of the isovector giant dipole resonances (IVGDR) were made to cover the inclusive angular distributions out to the second minimum. Study of the giant resonance decay process provides further understanding of the resonances. This study was carried out by observing the (π + , π 0 p) coincident reactions involving the resonances of 9 B and 13 N excited from 9 Be and 13 C nuclei. These measurements determined the spectra of the decay protons. This method also permitted a decomposition of the giant resonances into their isospin components. The multipolarities of the resonances were revealed by the decay proton angular correlations which, for dipoles, are of the form 1 + A 2 P 2 (cos θ)

  6. Single-Photon Interference due to Motion in an Atomic Collective Excitation

    Science.gov (United States)

    Whiting, D. J.; Šibalić, N.; Keaveney, J.; Adams, C. S.; Hughes, I. G.

    2017-06-01

    We experimentally demonstrate the heralded generation of bichromatic single photons from an atomic collective spin excitation (CSE). The photon arrival times display collective quantum beats, a novel interference effect resulting from the relative motion of atoms in the CSE. A combination of velocity-selective excitation with strong laser dressing and the addition of a magnetic field allows for exquisite control of this collective beat phenomenon. The present experiment uses a diamond scheme with near-IR photons that can be extended to include telecommunications wavelengths or modified to allow storage and retrieval in an inverted-Y scheme.

  7. Development of the system for excitation function automatic measurement of nuclear reactions

    International Nuclear Information System (INIS)

    Sapozhnikov, A.B.

    2004-01-01

    Full text: The resonance nuclear reaction method is applied at the tandem accelerator UKP-2-1 to determinate films thickness and obtain light element depth distribution. The system for automatic measurement of the nuclear reaction excitation curve has been developed. It allowed to obtain an excitation function of nuclear reaction using continuous changing potential of the target with energy step of 6 eV. Saw-tooth voltage with amplitude up to 6 kV from the block of scanning beam is fed to a target. The amplitude is determined by constant voltage from the scanning beam block control. Nal(Tl) detector detects gamma quanta - the products of a nuclear reaction and transforms they in voltage impulses. The impulses through the amplifier income in the single-channel analyzer which forms impulses to start the analog-to-digital converter. The value of saw-tooth voltage corresponding to the moment of gamma quantum detection is read by the analog-to-digital converter, where it is transformed to digital code and transmitted to the computer. The computer program has been developed to control the process of accumulation of excitation function. The dependence a detected γ-quanta yield from a target potential is automatically plotted by the program. This dependence corresponds to the nuclear reaction excitation function. If scanning amplitude is not enough in order to scan need depth of a sample, an operator increases energy of the proton beam changing high voltage potential of the terminal up 3 keV and measures the nuclear reaction excitation function with the new energy. This procedure can be repeated some times. After that 'sewing' of excitation functions is carried out by the program under the hypothesis that nuclear reaction yield in last points be identical

  8. Collective Excitations in Protein as a Measure of Balance Between its Softness and Rigidity

    International Nuclear Information System (INIS)

    Shrestha, Utsab R.; Bhowmik, Debsindhu; Van Delinder, Kurt W.; Mamontov, Eugene; O’Neill, Hugh

    2017-01-01

    Here, we elucidate the protein activity from the perspective of protein softness and flexibility by studying the collective phonon-like excitations in a globular protein, human serum albumin (HSA), and taking advantage of the state-of-the-art inelastic X-ray scattering (IXS) technique. Such excitations demonstrate that the protein becomes softer upon thermal denaturation due to disruption of weak noncovalent bonds. On the other hand, no significant change in the local excitations is detected in ligand- (drugs) bound HSA compared to the ligand-free HSA. These results clearly suggest that the protein conformational flexibility and rigidity are balanced by the native protein structure for biological activity.

  9. Collective Excitations in Protein as a Measure of Balance Between its Softness and Rigidity

    Energy Technology Data Exchange (ETDEWEB)

    Shrestha, Utsab R. [Wayne State Univ., Detroit, MI (United States). Dept. of Physics and Astronomy; Bhowmik, Debsindhu [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Computational Science and Engineering Division; Van Delinder, Kurt W. [Wayne State Univ., Detroit, MI (United States). Dept. of Physics and Astronomy; Mamontov, Eugene [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical and Engineering Materials Division; O’Neill, Hugh [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biology and Soft Matter Division; Zhang, Qiu [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biology and Soft Matter Division; Alatas, Ahmet [Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source; Chu, Xiang-Qiang [Wayne State Univ., Detroit, MI (United States). Dept. of Physics and Astronomy

    2017-01-12

    Here, we elucidate the protein activity from the perspective of protein softness and flexibility by studying the collective phonon-like excitations in a globular protein, human serum albumin (HSA), and taking advantage of the state-of-the-art inelastic X-ray scattering (IXS) technique. Such excitations demonstrate that the protein becomes softer upon thermal denaturation due to disruption of weak noncovalent bonds. On the other hand, no significant change in the local excitations is detected in ligand- (drugs) bound HSA compared to the ligand-free HSA. These results clearly suggest that the protein conformational flexibility and rigidity are balanced by the native protein structure for biological activity.

  10. Influence of collective excitations on pre-equilibrium and equilibrium processes

    International Nuclear Information System (INIS)

    Ignatyuk, A.V.; Lunev, V.P.

    1990-01-01

    The influence of the collective states excitations on equilibrium and preequilibrium processes in reaction is discussed. It is shown that for a consistent description of the contribution of preequilibrium and equilibrium compound processes collective states should be taken into account in the level density calculations. The microscopic and phenomenological approaches for the level density calculations are discussed. 13 refs.; 8 figs

  11. {gamma}-radiation of excited nuclear discrete levels in peripheral heavy ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Korotkikh, V.L.; Chikin, K.A. [Scobeltsyn Institute of Nuclear Physics, Moscow State University (Russian Federation)

    2002-06-01

    A new process of a nuclear excitation to discrete states in peripheral heavy ion collisions is studied. High-energy photons are emitted by the exited nuclei with energies up to a few tens of GeV at angles of a few hundred microradians with respect to the beam direction. We show that a two-stage process, where an electron-positron pair is produced by virtual photons emitted by nuclei and then the electron or positron excites the nucleus, has a large cross-section. It is equal to about 5 b for CaCa collisions. On the one hand, it produces a significant {gamma}-rays background in the nuclear fragmentation region but, on the other hand, it could be used for monitoring the nuclear beam intensity at the LHC. These secondary nuclear photons could be a good signal for triggering peripheral nuclear collisions. (orig.)

  12. γ-radiation of excited nuclear discrete levels in peripheral heavy ion collisions

    Science.gov (United States)

    Korotkikh, V. L.; Chikin, K. A.

    A new process of a nuclear excitation to discrete states in peripheral heavy ion collisions is studied. High-energy photons are emitted by the exited nuclei with energies up to a few tens of GeV at angles of a few hundred microradians with respect to the beam direction. We show that a two-stage process, where an electron-positron pair is produced by virtual photons emitted by nuclei and then the electron or positron excites the nucleus, has a large cross-section. It is equal to about 5 b for CaCa collisions. On the one hand, it produces a significant γ-rays background in the nuclear fragmentation region but, on the other hand, it could be used for monitoring the nuclear beam intensity at the LHC. These secondary nuclear photons could be a good signal for triggering peripheral nuclear collisions.

  13. γ-radiation of excited nuclear discrete levels in peripheral heavy ion collisions

    International Nuclear Information System (INIS)

    Korotkikh, V.L.; Chikin, K.A.

    2002-01-01

    A new process of a nuclear excitation to discrete states in peripheral heavy ion collisions is studied. High-energy photons are emitted by the exited nuclei with energies up to a few tens of GeV at angles of a few hundred microradians with respect to the beam direction. We show that a two-stage process, where an electron-positron pair is produced by virtual photons emitted by nuclei and then the electron or positron excites the nucleus, has a large cross-section. It is equal to about 5 b for CaCa collisions. On the one hand, it produces a significant γ-rays background in the nuclear fragmentation region but, on the other hand, it could be used for monitoring the nuclear beam intensity at the LHC. These secondary nuclear photons could be a good signal for triggering peripheral nuclear collisions. (orig.)

  14. Discrimination of nuclear spin isomers exploiting the excited state dynamics of a quinodimethane derivative

    Energy Technology Data Exchange (ETDEWEB)

    Obaid, Rana [Institut für Theoretische Chemie, Universität Wien, Währinger Str. 17, 1090 Wien (Austria); Faculty of Pharmacy, Al-Quds University, Abu Dis, Palestine (Country Unknown); Kinzel, Daniel; Oppel, Markus, E-mail: markus.oppel@univie.ac.at; González, Leticia [Institut für Theoretische Chemie, Universität Wien, Währinger Str. 17, 1090 Wien (Austria)

    2014-10-28

    Despite the concept of nuclear spin isomers (NSIs) exists since the early days of quantum mechanics, only few approaches have been suggested to separate different NSIs. Here, a method is proposed to discriminate different NSIs of a quinodimethane derivative using its electronic excited state dynamics. After electronic excitation by a laser field with femtosecond time duration, a difference in the behavior of several quantum mechanical operators can be observed. A pump-probe experimental approach for separating these different NSIs is then proposed.

  15. Critical excitation method for calculating earthquake effects on nuclear plant structures: an assessment study. Technical report

    International Nuclear Information System (INIS)

    Bedrosian, B.; Barbela, M.; Drenick, R.F.; Tsirk, A.

    1980-10-01

    The critical excitation method provides a new, alternative approach to methods presently used for seismic analysis of nuclear power plant structures. The critical excitation method offers the advantages that: (1) it side-steps the assumptions regarding the probability distribution of ground motions, and (2) it does not require an artificial, and to some extent arbitrarily generated, time history of ground motion, both features to which structural integrity analyses are sensitive. Potential utility of the critical excitation method is studied from the user's viewpoint. The method is reviewed and compared with the response spectrum method used in current practice, utilizing the reactor buildings of a PWR and a BWR plant in case studies. Two types of constraints on critical excitation were considered in the study. In one case, only an intensity limit was used. In the other case, imposition of an intensity limit together with limits on the maximum acceleration and/or velocity for the critical excitation is considered

  16. Influence of nuclear dissipation on fission dynamics of the excited ...

    Indian Academy of Sciences (India)

    A stochastic approach to fission dynamics based on two-dimensional Langevin equations was applied to calculate the anisotropy of the fission fragments angular distribution and average pre-scission neutron multiplicities for the compound nucleus 248Cf formed in the $${16}$O+$^{232}$Th reactions. Postsaddle nuclear ...

  17. Probing single-particle and collective states in atomic nuclei with Coulomb excitation

    CERN Document Server

    DiJulio, Douglas

    A series of experiments and developments, related to stable and radioactive isotopes, have been carried out. These studies have focused on measuring the low-lying excitations of spherical and deformed nuclei using electromagnetic (Coulomb) excitation and also on developments in detector technology for upcoming radioactive ion beams facilities. The low-lying excitations in the nuclei 107,109Sn and 107In have been investigated using low-energy Coulomb excitation at the REX-ISOLDE facility at CERN. The measured reduced transition probabilities were compared to predictions of nuclear structure models. In addition, a relativistic Coulomb excitation experiment was carried out using the FRS at GSI with the nucleus 104Sn. These radioactive ion beam experiments provide important constraints for large-scale-shell-model calculations in the region of the doubly magic nucleus 100Sn. A stable Coulomb excitation experiment was also carried out in order to explore the properties of low-lying structures in the nucleus 170Er...

  18. University of Florida nuclear pumped laser program. [excitation of laser gaseous

    Science.gov (United States)

    Schneider, R. T.

    1979-01-01

    The mechanism of excitation of laser gases by fast ions (triton, proton, or fission fragments) and especially any role UF6 might play in radiative deexcitation of these gases were investigated. Population densities of excited important for laser action were obtained. Nuclear pumped CW-laser systems, especially He-Ne and CO2, were studied using steady state reactors. It was demonstrated that He-Ne lases in a CW-mode with nuclear pumping at both the red and the infrared transition. The infrared transition was observed to be superradiant.

  19. Consistency of nuclear thermometric measurements at moderate excitation

    International Nuclear Information System (INIS)

    Rana, T. K.; Bhattacharya, C.; Kundu, S.; Banerjee, K.; Bhattacharya, S.; Dey, A.; Ghosh, T. K.; Mukherjee, G.; Meena, J. K.; Gupta, D.; Mukhopadhyay, S.; Pandit, D.; Banerjee, S. R.; Roy, A.; Dhara, P.

    2008-01-01

    A comparison of various thermometric techniques used for the estimation of nuclear temperature has been made from the decay of hot composite 32 S* produced in the reaction 20 Ne (145 MeV) + 12 C. It is shown that the temperatures estimated by different techniques, known to vary significantly in the Fermi energy domain, are consistent with each other within experimental limits for the system studied here

  20. Direct evidence of fadeout of collective enhancement in nuclear level density

    Directory of Open Access Journals (Sweden)

    K. Banerjee

    2017-09-01

    Full Text Available The phenomenon of collective enhancement in nuclear level density and its fadeout has been probed using neutron evaporation study of two strongly deformed (173Lu, 185Re, and one spherical (201Tl compound nuclei over the excitation energy (E⁎ range of ∼22–56 MeV. Clear signature of the fadeout of collective enhancement in nuclear level density was observed for the first time in both the deformed evaporation residues 172Lu and 184Re at an excitation energy range ∼14–21 MeV. Calculations based on finite temperature density functional theory, as well as macroscopic–microscopic shape transition model, have strongly established a close correlation between the observed fadeout of collective enhancement and a deformed to spherical nuclear shape transition in these nuclei occurring in the same excitation energy zone. Interestingly, a weak signature of fadeout has also been observed for the spherical residue 200Tl. This is due to a similar shape transition of the deformed excited state configuration of 200Tl.

  1. Magnetochromic sensing and size-dependent collective excitations in iron oxide nanoparticles

    Science.gov (United States)

    O'Neal, Kenneth R.; Patete, Jonathan M.; Chen, Peng; Nanavati, Ruhani; Holinsworth, Brian S.; Smith, Jacqueline M.; Marques, Carlos; Simonson, Jack W.; Aronson, Meigan C.; McGill, Stephen A.; Wong, Stanislaus S.; Musfeldt, Janice L.

    2017-03-01

    We combine optical and magneto-optical spectroscopies with complementary vibrational and magnetic property measurements to reveal finite length scale effects in nanoscale α -Fe2O3 . Analysis of the d -to-d on-site excitations uncovers enhanced color contrast at particle sizes below approximately 75 nm due to size-induced changes in spin-charge coupling that are suppressed again below the superparamagnetic limit. These findings provide a general strategy for amplifying magnetochromism in α -Fe2O3 and other iron-containing nanomaterials that may be useful for advanced sensing applications. We also unravel the size dependence of collective excitations in this iconic antiferromagnet.

  2. Isomer depletion as experimental evidence of nuclear excitation by electron capture

    Science.gov (United States)

    Chiara, C. J.; Carroll, J. J.; Carpenter, M. P.; Greene, J. P.; Hartley, D. J.; Janssens, R. V. F.; Lane, G. J.; Marsh, J. C.; Matters, D. A.; Polasik, M.; Rzadkiewicz, J.; Seweryniak, D.; Zhu, S.; Bottoni, S.; Hayes, A. B.; Karamian, S. A.

    2018-02-01

    The atomic nucleus and its electrons are often thought of as independent systems that are held together in the atom by their mutual attraction. Their interaction, however, leads to other important effects, such as providing an additional decay mode for excited nuclear states, whereby the nucleus releases energy by ejecting an atomic electron instead of by emitting a γ-ray. This ‘internal conversion’ has been known for about a hundred years and can be used to study nuclei and their interaction with their electrons. In the inverse process—nuclear excitation by electron capture (NEEC)—a free electron is captured into an atomic vacancy and can excite the nucleus to a higher-energy state, provided that the kinetic energy of the free electron plus the magnitude of its binding energy once captured matches the nuclear energy difference between the two states. NEEC was predicted in 1976 and has not hitherto been observed. Here we report evidence of NEEC in molybdenum-93 and determine the probability and cross-section for the process in a beam-based experimental scenario. Our results provide a standard for the assessment of theoretical models relevant to NEEC, which predict cross-sections that span many orders of magnitude. The greatest practical effect of the NEEC process may be on the survival of nuclei in stellar environments, in which it could excite isomers (that is, long-lived nuclear states) to shorter-lived states. Such excitations may reduce the abundance of the isotope after its production. This is an example of ‘isomer depletion’, which has been investigated previously through other reactions, but is used here to obtain evidence for NEEC.

  3. Collective 2{sup +}{sub 1} excitations in {sup 206}Po and {sup 208,210}Rn

    Energy Technology Data Exchange (ETDEWEB)

    Grahn, T.; Auranen, K.; Herzan, A.; Jakobsson, U.; Julin, R.; Konki, J.; Peura, P.; Rahkila, P.; Stolze, S. [Department of Physics, University of Jyvaskyla (Finland); Helsinki Institute of Physics, Helsinki (Finland); Pakarinen, J. [Department of Physics, University of Jyvaskyla (Finland); Helsinki Institute of Physics, Helsinki (Finland); CERN-ISOLDE, PH Department, CERN, Geneva (Switzerland); Jokiniemi, L.; Suhonen, J. [Department of Physics, University of Jyvaskyla (Finland); Albers, M.; Blazhev, A.; Lewandowski, L.; Moschner, K.; Pfeiffer, M.; Radeck, D.; Reiter, P.; Rudiger, M.; Seidlitz, M.; Siebeck, B.; Steinbach, T.; Thoele, P.; Warr, N.; Vogt, A. [Universitaet zu Koeln, Institut fuer Kernphysik, Koeln (Germany); Bauer, C.; Boenig, S.; Kroell, T.; Thuerauf, M. [TU Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); Bernards, C. [Yale University, Wright Nuclear Structure Laboratory, New Haven, CT (United States); Butler, P.A. [University of Liverpool, Department of Physics, Oliver Lodge Laboratory, Liverpool (United Kingdom); Damyanova, A. [Universite de Geneve (Switzerland); Coster, T. de; Witte, H. de; Elseviers, J.; Huyse, M.; Kesteloot, N.; Reynders, K.; Sambi, S.; Wrzosek-Lipska, K. [Department of Physics, Instituut voor Kern- en Stralingsfysica, Leuven (Belgium); Gaffney, L.P. [University of Liverpool, Department of Physics, Oliver Lodge Laboratory, Liverpool (United Kingdom); Department of Physics, Instituut voor Kern- en Stralingsfysica, Leuven (Belgium); University of the West of Scotland, School of Engineering, Paisley (United Kingdom); Rapisarda, E.; Duppen, P. van [Department of Physics, Instituut voor Kern- en Stralingsfysica, Leuven (Belgium); CERN-ISOLDE, PH Department, CERN, Geneva (Switzerland); Salsac, M.D.; Zielinska, M. [CEA-Saclay, Gif-sur-Yvette (France); Scheck, M. [TU Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); University of the West of Scotland, School of Engineering, Paisley (United Kingdom); Venhart, M.; Veselsky, M. [Slovak Academy of Sciences, Institute of Physics, Bratislava 45 (Slovakia); Vermeulen, M.J. [University of York, Department of Physics, York (United Kingdom); Werner, V. [TU Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); Yale University, Wright Nuclear Structure Laboratory, New Haven, CT (United States)

    2016-11-15

    In the present study, B(E2; 2{sup +}{sub 1} → 0{sup +}{sub 1}) values have been measured in the {sup 208,210}Rn and {sup 206}Po nuclei through Coulomb excitation of re-accelerated radioactive beams in inverse kinematics at CERN-ISOLDE. These nuclei have been proposed to lie in, or at the boundary of the region where the seniority scheme should persist. However, contributions from collective excitations are likely to be present when moving away from the N = 126 closed shell. Such an effect is confirmed by the observed increased collectivity of the 2{sup +}{sub 1} → 0{sup +}{sub 1} transitions. Experimental results have been interpreted with the aid of theoretical studies carried out within the BCS-based QRPA framework. (orig.)

  4. ‘Which-way’ collective atomic spin excitation among atomic ensembles by photon indistinguishability

    International Nuclear Information System (INIS)

    Zhang Guowan; Bian Chenglin; Chen, L Q; Ou, Z Y; Zhang Weiping

    2012-01-01

    In spontaneous Raman scattering in an atomic ensemble, a collective atomic spin wave is created in correlation with the Stokes field. When the Stokes photons from two or more such atomic ensembles are made indistinguishable, a ‘which-way’ collective atomic spin excitation is generated among the independent atomic ensembles. We demonstrate this phenomenon experimentally by reading out the atomic spin excitations and observing interference between the read-out beams. When a single-photon projective measurement is made on the indistinguishable Stokes photons, this simple scheme can be used to entangle independent atomic ensembles. Compared to other currently used methods, this scheme can be easily scaled up and has greater efficiency. (paper)

  5. Modeling Electronic-Nuclear Interactions for Excitation Energy Transfer Processes in Light-Harvesting Complexes.

    Science.gov (United States)

    Lee, Mi Kyung; Coker, David F

    2016-08-18

    An accurate approach for computing intermolecular and intrachromophore contributions to spectral densities to describe the electronic-nuclear interactions relevant for modeling excitation energy transfer processes in light harvesting systems is presented. The approach is based on molecular dynamics (MD) calculations of classical correlation functions of long-range contributions to excitation energy fluctuations and a separate harmonic analysis and single-point gradient quantum calculations for electron-intrachromophore vibrational couplings. A simple model is also presented that enables detailed analysis of the shortcomings of standard MD-based excitation energy fluctuation correlation function approaches. The method introduced here avoids these problems, and its reliability is demonstrated in accurate predictions for bacteriochlorophyll molecules in the Fenna-Matthews-Olson pigment-protein complex, where excellent agreement with experimental spectral densities is found. This efficient approach can provide instantaneous spectral densities for treating the influence of fluctuations in environmental dissipation on fast electronic relaxation.

  6. Excitation of radial collective modes in a quantum dot: Beyond linear response

    Energy Technology Data Exchange (ETDEWEB)

    Gudmundsson, Vidar; Hauksson, Sigtryggur; Johnsen, Arni; Reinisch, Gilbert [Science Institute, University of Iceland, Reykjavik (Iceland); Manolescu, Andrei [School of Science and Engineering, Reykjavik University, Reykjavik (Iceland); Besse, Christophe [Institut de Mathematiques de Toulouse UMR 5219, Universite de Toulouse, CNRS UPS IMT (France); Dujardin, Guillaume [Inria Lille Nord-Europe et Laboratoire Paul Painleve UMR CNRS 8524, Villeneuve d' Ascq (France)

    2014-07-15

    The recent results on the linear breathing mode of the excitation spectrum of a quantum dot obtained by McDonald et. al [Phys. Rev. Lett. 111, 256801 (2013)] are extended to the nonlinear regime. To accomplish this and analyze the results the response of five different models of two interacting electrons in a quantum dot to an external short lived radial excitation that is strong enough to excite the system well beyond the linear response regime is compared. The models considered describe the Coulomb interaction between the electrons in different ways ranging from mean-field approaches to configuration interaction (CI) models, where the two-electron Hamiltonian is diagonalized in a large truncated Fock space. The radially symmetric excitation is selected in order to severely put to test the different approaches to describe the interaction and correlations of an electron system in a nonequilibrium state. As can be expected for the case of only two electrons none of the mean-field models can in full details reproduce the results obtained by the CI model. Nonetheless, some linear and nonlinear characteristics are reproduced reasonably well. All the models show activation of an increasing number of collective modes as the strength of the excitation is increased. By varying slightly the confinement potential of the dot it was observed how sensitive the properties of the excitation spectrum are to the Coulomb interaction and its correlation effects. In order to approach closer the question of nonlinearity one of the mean-field models has been solved directly in a nonlinear fashion without resorting to iterations. (copyright 2014 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. The structure of nuclear states at low, intermediate and high excitation energies

    International Nuclear Information System (INIS)

    Soloviev, V.G.

    1976-01-01

    It is shown that within the model based on the quasiparticle-phonon interaction one can obtain the description of few-quasiparticle components of nuclear states at low, intermediate and high excitation energies. For the low-lying states the energy of each level is calculated. The few-quasiparticle components at intermediate and high excitation energies are represented to be averaged in certain energy intervals and their characteri stics are given as the corresponding strength functions. The fragmentation of single-particle states in deformed nuclei is studied. It is shown that in the distribution of the single-particle strength alongside with a large maximum there appear local maxima and the distribution itself has a long tail. The dependence of neutron strength functions on the excitation energy is investigated for the transfer reaction of the type (d,p) and (d,t). The s,- p,- and d-wave neutron strength functions are calculated at the neutron binding energy Bn. A satisfactory agreement with experiment is obtained. The energies and Elambda-strength functions for giant multipole resonances in deformed nuclei are calculated. The energies of giant quadrupole and octupole resonances are calculated. Their widths and fine structure are being studied. It is stated that to study the structure of highly excited states it is necessary to find the values of many-quasiparticle components of the wave functions. The ways of experimental determination of these components based on the study of γ-transitions between highly excited states are discussed

  8. Interplay between collective and single particle excitations around neutron-rich doubly-magic nuclei

    Directory of Open Access Journals (Sweden)

    Leoni S.

    2016-01-01

    Full Text Available The excitation spectra of nuclei with one or two particles outside a doubly-magic core are expected to be dominated, at low energy, by the couplings between phonon excitations of the core and valence particles. A survey of the experimental situation is given for some nuclei lying in close proximity of neutron-rich doubly-magic systems, such as 47,49Ca, 133Sb and 210Bi. Data are obtained with various types of reactions (multinucleon transfer with heavy ions, cold neutron capture and neutron induced fission of 235U and 241Pu targets, with the employment of complex detection systems based on HPGe arrays. A comparison with theoretical calculations is also presented, in terms of large shell model calculations and of a phenomenological particle-phonon model. In the case of 133Sb, a new microscopic “hybrid” model is introduced: it is based on the coupling between core excitations (both collective and non-collective of the doubly-magic core and the valence nucleon, using the Skyrme effective interaction in a consistent way.

  9. Three-mode resonant coupling of collective excitations in a Bose-Einstein condensate

    International Nuclear Information System (INIS)

    Ma Yongli; Huang, Guoxiang; Hu Bambi

    2005-01-01

    We make a systematic study of the resonant mode coupling of the collective excitations at zero temperature in a Bose-Einstein condensate (BEC). (i) Based on the Gross-Pitaevskii equation we derive a set of nonlinearly coupled envelope equations for a three-mode resonant interaction (TMRI) by means of a method of multiple scales. (ii) We calculate the coupling matrix elements for the TMRI and show that the divergence appearing in previous studies can be eliminated completely by using a Fetter-like variational approximation for the ground-state wave function of the condensate. (iii) We provide the selection rules in mode-mode interaction processes [including TMRI and second-harmonic generation (SHG)] according to the symmetry of the excitations. (iv) By solving the nonlinearly coupled envelope equations we obtain divergence-free nonlinear amplitudes for the TMRI and SHG processes and show that our theoretical results on the shape oscillations of the condensate agree well with the experimental ones. We suggest also an experiment to check the theoretical prediction of the present study on the TMRI of collective excitations in a BEC

  10. Collective excitation frequencies and vortices of a Bose-Einstein condensed state with gravitylike interatomic attraction

    International Nuclear Information System (INIS)

    Ghosh, Tarun Kanti

    2002-01-01

    We study the collective excitations of a neutral atomic Bose-Einstein condensate with gravitylike 1/r interatomic attraction induced by an electromagnetic wave. Using the time-dependent variational approach, we derive an analytical spectrum for monopole and quadrupole mode frequencies of a gravitylike self-bound Bose condensed state at zero temperature. We also analyze the excitation frequencies of the Thomas-Fermi-gravity (TF-G) and gravity (G) regimes. Our result agrees excellently with that of Giovanazzi et al. [Europhysics Lett., 56, 1 (2001)], which is obtained within the sum-rule approach. We also consider the vortex state. We estimate the superfluid coherence length and the critical angular frequencies to create a vortex around the z axis. We find that the TF-G regime can exhibit the superfluid properties more prominently than the G regime. We find that the monopole mode frequency of the condensate decreases due to the presence of a vortex

  11. Excitation energy and angular momentum dependence of the nuclear level densities

    International Nuclear Information System (INIS)

    Razavi, R.; Kakavand, T.; Behkami, A. N.

    2007-01-01

    We have investigated the excitation energy (E) dependence of nuclear level density for Bethe formula and constant temperature model. The level density parameter aa nd the back shifted energy from the Bethe formula are obtained by fitting the complete level schemes. Also the level density parameters from the constant temperature model have been determined for several nuclei. we have shown that the microscopic theory provides more precise information on the nuclear level densities. On the other hand, the spin cut-off parameter and effective moment of inertia are determined by studying of the angular momentum (J) dependence of the nuclear level density, and effective moment of inertia is compared with rigid body value.

  12. Inelastic electron and Raman scattering from the collective excitations in quantum wires: Zero magnetic field

    Directory of Open Access Journals (Sweden)

    Manvir S. Kushwaha

    2013-04-01

    intrasubband and intersubband single-particle as well as collective excitations], the loss functions for the IES and the Raman intensity for the ILS. We observe that it is the collective (plasmon excitations that largely contribute to the predominant peaks in the energy-loss and the Raman spectra. The inductive reasoning is that the IES can be a potential alternative of the overused ILS for investigating collective excitations in quantum wires. We trust that this research work shall be useful to all – from novice to expert and from theorist to experimentalist – who believe in the power of traditional science.

  13. Inelastic electron and Raman scattering from the collective excitations in quantum wires: Zero magnetic field

    Science.gov (United States)

    Kushwaha, Manvir S.

    2013-04-01

    intersubband single-particle as well as collective excitations], the loss functions for the IES and the Raman intensity for the ILS. We observe that it is the collective (plasmon) excitations that largely contribute to the predominant peaks in the energy-loss and the Raman spectra. The inductive reasoning is that the IES can be a potential alternative of the overused ILS for investigating collective excitations in quantum wires. We trust that this research work shall be useful to all - from novice to expert and from theorist to experimentalist - who believe in the power of traditional science.

  14. Nuclear shapes and nuclear structure at low excitation energies. Abstracts of contributed papers

    International Nuclear Information System (INIS)

    Dykstra, F.; Goutte, D.; Sauvage, J.; Vergnes, M.

    1994-01-01

    103 papers are presented on recent theoretical and experimental results on nuclear structure investigation. Short communications were published in this volume, all of which were indexed separately for the INIS database. (R.P.)

  15. Light particle emission as a probe of reaction mechanism and nuclear excitation

    International Nuclear Information System (INIS)

    Guerreau, D.

    1989-01-01

    The central part of these lectures will be dealing with the problem of energy dissipation. A good understanding of the mechanisms for the dissipation requires to study both peripheral and central collisions or, in other words, to look at the impact paramenter dependence. This should also provide valuable information on the time scale. In order to probe the reaction mechanism and nuclear excitation, one of the most powerful tool is unquestionably the observation of light particle emission, including neutrons and charged particles. Several examples will be discussed related to peripheral collisions (the fate of transfer reactions, the excitation energy generation, the production of projectile-like fragments) as well as inner collisions for which extensive studies have demonstrated the strength of intermediate energy heavy ions for the production of very hot nuclei and detailed study of their decay properties

  16. Preparations for an optical access to the lowest nuclear excitation in {sup 229}Th

    Energy Technology Data Exchange (ETDEWEB)

    Wense, Lars v.d.; Seiferle, Benedict; Thirolf, Peter G. [Ludwig-Maximilians-Universitaet Muenchen (Germany); Laatiaoui, Mustapha [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany)

    2015-07-01

    The isomeric lowest excited nuclear level of {sup 229}Th has been indirectly measured to be 7.6±0.5 eV (163±11 nm). This low transition energy, compared to energies typically involved in nuclear processes, would allow for the application of laser-spectroscopic methods. Also considering the isomeric lifetime of the excited state (estimated to be 10{sup 3} to 10{sup 4} s), which leads to an extremely sharp linewidth of Δω/ω ∝ 10{sup -20}, the isomer becomes a strong candidate for a nuclear-based frequency standard. In order to directly detect the isomeric ground-state decay and improve the accuracy of its energy as a prerequisite for an all-optical control, {sup 229m}Th is populated via a 2% decay branch in the α decay of {sup 233}U. The Thorium ions are extracted and cooled with the help of a buffer-gas stopping cell and an RFQ-cooler. In order to suppress accompanying α decay chain products other than {sup 229}Th, a quadrupole mass spectrometer (QMS) is used. Following the QMS, the Thorium isomeric decay is expected to be detectable. Internal conversion as well as photonic decay is probed via different detection techniques. Latest results are presented.

  17. Radioactive nuclear beams and the evolution of collectivity in nuclei

    International Nuclear Information System (INIS)

    Casten, R.F.; Zamfir, N.V.

    1995-01-01

    The advent of Radioactive Nuclear Beams (RNBs) has opened up new nuclear territories to exploration. Recent theoretical work suggests that nuclear structure in these new regions may be unlike anything observed to date and that its study may substantially alter our concepts of shell structure, collectivity and the evolution of nuclear behavior. To face the challenge of inevitably low RNB intensities, new, more efficient signatures of structure and new experimental techniques are being developed. We discuss these topics and also summarize the current status of RNB facilities and facility planning in North America

  18. Radioactive nuclear beams and the evolution of collectivity in nuclei

    International Nuclear Information System (INIS)

    Casten, R.F.; Zamfir, N.V.

    1996-01-01

    The advent of Radioactive Nuclear Beams (RNBs) has opened up new nuclear territories to explorations. Recent theoretical work suggests that nuclear structure in these new regions may be unlike anything observed to date and that its study may substantially alter our concepts of shell structure, collectivity and the evaluation of nuclear behaviour. To face the challenge of inevitably low RNB intensities, new, more efficient signatures of structure and new experimental techniques are being developed. We discuss these topics and also summarize the current status of RNB facilities and facility planning in North America. (authors)

  19. The effect of a neutrino magnetic moment on nuclear excitation processes

    International Nuclear Information System (INIS)

    Dodd, A.C.; Papageorgiu, E.; Ranfone, S.

    1991-01-01

    It is shown that the MeV-range neutrinos with a magnetic moment of ≅ 10 -11 Bohr magnetons would excite nuclei, like 12 C, with cross sections comparable to those obtained in the Standard Model. This implies the possibility of improving the present experimental bounds on the magnetic moment of any flavour of neutrinos by one order of magnitude. Such a magnetic moment would also enhance the coherent neutrino-nuclear scattering in low-temperature detectors, enabling them to set comparable limits. (author)

  20. Collection of guides for safety examination by Nuclear Safety Commission

    International Nuclear Information System (INIS)

    1981-01-01

    The examination on the safety for the application of permission to install nuclear facilities or to change the installation in the Nuclear Safety Commission is carried out on the basis of various guides instituted by the Nuclear Safety Commission or the old Atomic Energy Commission. Especially as for the problems common to various nuclear reactors, the Committee on Examination of Nuclear Reactor Safety performs the examination by determining the rules for them. These guides and others have been published in the monthly report of the Nuclear Safety Commission and others, but for the sake of convenient use, this collection of guides has been published. As for the guides, the letter of decision by the commission, the text of the guides and the explanation or the criteria for judgement are described, and in the case of rules, similar description is made. In this collection of guides, 20 guides and 11 rules are included. These are related to the location of nuclear power stations, the safety examination of nuclear power stations, radiation control, fire protection, and the performance of reactor systems. (Kako, I.)

  1. Energy transfer from excited cyclobutane-t chemically activated by nuclear recoil reaction

    International Nuclear Information System (INIS)

    Nogar, N.S.

    1976-01-01

    Relative energy transfer efficiencies were determined for collisions between highly excited cyclobutane-t and a number of thermal bath gases, including nitrogen, tetrafluoromethane, the noble gases, and cyclobutane. The excited cyclobutane-t was produced with a broad spectrum of energies about a mean energy of 5 eV by replacement of hydrogen with nuclear recoil tritium. The distribution of cyclobutane-t included a fraction produced at such low energies that it was not subjected to unimolecular decomposition, a fraction always found as the decomposition product, ethylene-t, and a fraction subject to competitive stabilization-decomposition reactions. The fraction of cyclobutane-t produced at such extreme energies that it was not subject to competitive unimolecular reaction was determined by curve-fitting the pressure dependence of ratio of cyclobutane-t to ethylene-t. Subsequent examination of the composition dependence of the ratio of competitive cyclobutane-t and ethylene-t yields gave energy transfer efficiencies for C 4 H 8 , CF 4 , N 2 , He, Ne, Ar, Kr, and Xe of 1.00:1.05:0.40, 0.12, 0.23, 0.24, 0.31, 0.39. The relative efficiencies found in this system are similar to those found in high energy conventional chemical activation systems, supporting this method for determination of energy transfer efficiencies following nuclear recoil activation. Cascade deactivation is demonstrated for this system and discussed with respect to energy transfer in hot atom activated systems

  2. Collective excitations and supersolid behavior of bosonic atoms inside two crossed optical cavities

    Science.gov (United States)

    Lang, J.; Piazza, F.; Zwerger, W.

    2017-12-01

    We discuss the nature of symmetry breaking and the associated collective excitations for a system of bosons coupled to the electromagnetic field of two optical cavities. For the specific configuration realized in a recent experiment at ETH [1, 2], we show that, in absence of direct intercavity scattering and for parameters chosen such that the atoms couple symmetrically to both cavities, the system possesses an approximate U(1) symmetry which holds asymptotically for vanishing cavity field intensity. It corresponds to the invariance with respect to redistributing the total intensity I={I}1+{I}2 between the two cavities. The spontaneous breaking of this symmetry gives rise to a broken continuous translation-invariance for the atoms, creating a supersolid-like order in the presence of a Bose-Einstein condensate. In particular, we show that atom-mediated scattering between the two cavities, which favors the state with equal light intensities {I}1={I}2 and reduces the symmetry to {{Z}}2\\otimes {{Z}}2, gives rise to a finite value ˜ \\sqrt{I} of the effective Goldstone mass. For strong atom driving, this low energy mode is clearly separated from an effective Higgs excitation associated with changes of the total intensity I. In addition, we compute the spectral distribution of the cavity light field and show that both the Higgs and Goldstone mode acquire a finite lifetime due to Landau damping at non-zero temperature.

  3. Collective excitations and the nature of Mott transition in undoped gapped graphene

    International Nuclear Information System (INIS)

    Jafari, S A

    2012-01-01

    The particle-hole continuum (PHC) for massive Dirac fermions provides an unprecedented opportunity for the formation of two collective split-off states, one in the singlet and the other in the triplet (spin-1) channel, when the short-range interactions are added to the undoped system. Both states are close in energy and are separated from the continuum of free particle-hole excitations by an energy scale of the order of the gap parameter Δ. They both disperse linearly with two different velocities, reminiscent of spin-charge separation in Luttinger liquids. When the strength of Hubbard interactions is stronger than a critical value, the velocity of singlet excitation, which we interpret as a charge composite boson, becomes zero and renders the system a Mott insulator. Beyond this critical point the low-energy sector is left with a linearly dispersing triplet mode - a characteristic of a Mott insulator. The velocity of the triplet mode at the Mott criticality is twice the velocity of the underlying Dirac fermions. The phase transition line in the space of U and Δ is in qualitative agreement with our previous dynamical mean field theory calculations. (paper)

  4. Entanglement between a Photonic Time-Bin Qubit and a Collective Atomic Spin Excitation

    Science.gov (United States)

    Farrera, Pau; Heinze, Georg; de Riedmatten, Hugues

    2018-03-01

    Entanglement between light and matter combines the advantage of long distance transmission of photonic qubits with the storage and processing capabilities of atomic qubits. To distribute photonic states efficiently over long distances several schemes to encode qubits have been investigated—time-bin encoding being particularly promising due to its robustness against decoherence in optical fibers. Here, we demonstrate the generation of entanglement between a photonic time-bin qubit and a single collective atomic spin excitation (spin wave) in a cold atomic ensemble, followed by the mapping of the atomic qubit onto another photonic qubit. A magnetic field that induces a periodic dephasing and rephasing of the atomic excitation ensures the temporal distinguishability of the two time bins and plays a central role in the entanglement generation. To analyze the generated quantum state, we use largely imbalanced Mach-Zehnder interferometers to perform projective measurements in different qubit bases and verify the entanglement by violating a Clauser-Horne-Shimony-Holt Bell inequality.

  5. Probing nuclear shell structure beyond the N=40 subshell using multiple Coulomb excitation and transfer experiments

    Energy Technology Data Exchange (ETDEWEB)

    Hellgartner, Stefanie Christine

    2015-11-13

    In this work, the N=40 subshell closure is investigated with two complementary methods using a radioactive {sup 72}Zn ISOLDE beam: One- and two-neutron transfer reactions and multiple Coulomb excitation. In the one-neutron transfer reaction, two new levels of {sup 73}Zn were discovered. The two-neutron transfer channel allowed to study the differential cross section of the ground state and the 2{sup +}{sub 1} state of {sup 74}Zn. In the Coulomb excitation experiment, the measured B(E2) values and quadrupole moments of {sup 72}Zn showed that the yrast states 0{sup +}{sub 1}, 2{sup +}{sub 1} and 4{sup +}{sub 1} are moderately collective. Contrary, the 0{sup +}{sub 2} state has a different structure, since it features a stronger closed N=40 configuration compared to the ground state.

  6. Effect of collective response on electron capture and excitation in collisions of highly charged ions with fullerenes.

    Science.gov (United States)

    Kadhane, U; Misra, D; Singh, Y P; Tribedi, Lokesh C

    2003-03-07

    Projectile deexcitation Lyman x-ray emission following electron capture and K excitation has been studied in collisions of bare and Li-like sulphur ions (of energy 110 MeV) with fullerenes (C(60)/C(70)) and different gaseous targets. The intensity ratios of different Lyman x-ray lines in collisions with fullerenes are found to be substantially lower than those for the gas targets, both for capture and excitation. This has been explained in terms of a model based on "solidlike" effect, namely, wakefield induced stark mixing of the excited states populated via electron capture or K excitation: a collective phenomenon of plasmon excitation in the fullerenes under the influence of heavy, highly charged ions.

  7. Coupled spin and charge collective excitations in a spin polarized electron gas

    International Nuclear Information System (INIS)

    Marinescu, D.C.; Quinn, J.J.; Yi, K.S.

    1997-01-01

    The charge and longitudinal spin responses induced in a spin polarized quantum well by a weak electromagnetic field are investigated within the framework of the linear response theory. The authors evaluate the excitation frequencies for the intra- and inter-subband transitions of the collective charge and longitudinal spin density oscillations including many-body corrections beyond the random phase approximation through the spin dependent local field factors, G σ ± (q,ω). An equation-of-motion method was used to obtain these corrections in the limit of long wavelengths, and the results are given in terms of the equilibrium pair correlation function. The finite degree of spin polarization is shown to introduce coupling between the charge and spin density modes, in contrast with the result for an unpolarized system

  8. Controlled Rephasing of Single Collective Spin Excitations in a Cold Atomic Quantum Memory.

    Science.gov (United States)

    Albrecht, Boris; Farrera, Pau; Heinze, Georg; Cristiani, Matteo; de Riedmatten, Hugues

    2015-10-16

    We demonstrate active control of inhomogeneous dephasing and rephasing for single collective atomic spin excitations (spin waves) created by spontaneous Raman scattering in a quantum memory based on cold 87Rb atoms. The control is provided by a reversible external magnetic field gradient inducing an inhomogeneous broadening of the atomic hyperfine levels. We demonstrate experimentally that active rephasing preserves the single photon nature of the retrieved photons. Finally, we show that the control of the inhomogeneous dephasing enables the creation of time-separated spin waves in a single ensemble followed by a selective read-out in time. This is an important step towards the implementation of a functional temporally multiplexed quantum repeater node.

  9. Development of the reactor lithium ampoule device for research of spectral-luminescent characteristics of nuclear-excited plasma

    Energy Technology Data Exchange (ETDEWEB)

    Batyrbekov, E.G. [National Nuclear Center of RK, Kurchatov (Kazakhstan); Gordienko, Yu. N., E-mail: gordienko@nnc.kz [National Nuclear Center of RK, Kurchatov (Kazakhstan); Ponkratov, Yu. V. [National Nuclear Center of RK, Kurchatov (Kazakhstan); Khasenov, M.U. [PI “National Laboratory Astana”, Astana (Kazakhstan); Tazhibayeva, I.L.; Barsukov, N.I.; Kulsartov, T.V.; Zaurbekova, Zh. A.; Tulubayev, Ye. Yu.; Skakov, M.K. [National Nuclear Center of RK, Kurchatov (Kazakhstan)

    2017-04-15

    Highlights: • The development procedure of the ampoule device for experiments with nuclear-excited plasma under neutron irradiation is described. • The methods of nuclear reactions’ energy conversion into the energy of optical radiation of nuclear-excited plasma are presented. • A scheme of reactor experiments, the experimental facility and experimental device to carry out the reactor experiments are considered. - Abstract: This paper describes the development procedure of the reactor ampoule device to perform the experiments on study of spectral luminescence characteristics of nuclear-excited plasma formed by products of {sup 6}Li(n,α){sup 3}H reaction under neutron irradiation at the IVG.1 M research reactor. The methods of nuclear reactions’ energy conversion into the energy of optical radiation of nuclear-excited plasma are presented. A scheme of reactor experiments, the experimental facility and experimental device to carry out the reactor experiments are considered in paper. The designed ampoule device is totally meets the requirements of irradiation experiments on the IVG.1M reactor.

  10. Collective Motion and Nuclear Dynamics. Predeal International Summer School

    International Nuclear Information System (INIS)

    Raduta, A.A.; Delion, D.S.; Ursu, I.I.

    1996-01-01

    This monograph contains 35 lectures given at the International Summer School on Collective motion and Nuclear Dynamics held in Predeal, Romania, in the period August 28 - September 9, 1995. A large variety of subjects were approached, ranging from classical to pure quantum mechanical formalisms, from standard nuclear structure to nuclear dynamics for finite temperature and relativistic effects of nuclear systems, from deuteron and alpha to heavy clusters, from exotic nuclei lying far away from the stability line to superdeformed nuclei. The sections (number of lectures) were as follows: 1.Nuclear structure (15); 2.Clustering phenomena and large amplitude motion (5); 3.Nuclear reactions: exotic nuclei, fusion, fission (5); 4.Nuclear dynamics: nonlinear effects and finite temperature (4); 5.Relativistic collisions (1); 6.Single and double beta decay; 7.Investigation of nuclear systems by electron scattering (1); 8.Metallic clusters; 9.Quantum groups (2). Non-included within these proceedings, there were presented also a number of 14 short communications, copies which may be obtained either directly from the authors or through care of the editor

  11. The eyes, ears and collective voice for nuclear transport

    International Nuclear Information System (INIS)

    Green, L.

    2000-01-01

    Transport is a vital part of the nuclear industry and the safety record of radioactive materials transport across the world is excellent. This record is due primarily to well-founded regulations developed by such intergovernmental organisations as the International Atomic Energy Agency and the International Maritime Organisation. It is due, also, to the professionalism of those in the industry. Attitudes to nuclear transport are important. They have the potential, if not heeded, and not responded to sensitively and convincingly to make life very much more difficult for those committed to the safe, reliable and efficient transport of nuclear materials. What is required is a balanced situation, which takes account both of the public's attitudes and industry's need for an efficient operation. The voices of the nuclear transport industry and those who value the industry need to be heard. The World Nuclear Transport Institute was established to provide the nuclear transport industry with the collective eyes, ears and voice in the key intergovernmental organisations which are so important to it. The nuclear transport industry has a safety record which could be regarded as a model for the transport of dangerous goods of all kinds. The industry is situated within a comprehensive and strict regime of national and international standards and regulations. That is the message to be disseminated, and that is the commitment of the World Nuclear Transport Institute as it works to protect and to promote the safe, efficient and reliable transport of radioactive materials. (author)

  12. Linearised collective Schroedinger equation for nuclear quadrupole surface vibrations

    International Nuclear Information System (INIS)

    Greiner, M.; Heumann, D.; Scheid, W.

    1990-11-01

    The linearisation of the Schroedinger equation for nuclear quadrupole surface vibrations yields a new spin degree of freedom, which is called collective spin and has a value of 3/2. With the introduction of collective spin dependent potentials, this linearised Schroedinger equation is then used for the description of low energy spectra and electromagnetic transition probabilities of some even-odd Xe, Ir and Au nuclei which have a spin 3/2 in their groundstate. (orig.)

  13. A seismic analysis of nuclear power plant components subjected to multi-excitations of earthquakes

    International Nuclear Information System (INIS)

    Ichiki, T.; Matsumoto, T.; Gunyasu, K.

    1977-01-01

    In this analysis, the modal analysis methods are used to determine the seismic responses of structural systems instead of the direct integration method. These results have been compared with some kinds of other analytical methods, and investigated the accuracy of numerical results of these analysis, applying to such components as Reactor Pressure Vessel and Reactor Internals of an actual plant. The results of this method of analysis are summarized as follows: (1) one of the seismic analysis methods concerning systems subjected to multi-excitations of earthquakes has been presented to the conference of JSME. Although the analytical theory presented to that conference is correct, it has a serious problem about the accuracy of numerical results. This computer program and theory cannot be used practically due to the time necessary to calculate. However, the method described in this paper overcomes those serious problems stated above and has no problem about the computer time and precision. So, it is possible to apply this method to the seismic design of an actual nuclear power plant practically. (2) The feed back effects of the seismic responses of Reactor Internals to Reactor Building are considered so small that we can separate the model of Reactor Internals from Reactor Building. (3) The results of seismic response of Reactor Internals are fairly consistent with those obtained from the model coupled with Reactor Building. (4) This analysis method can be extended to the model of Reactor Internals subjected to more than two random excitations of earthquakes. (5) It is possible that this analysis method is also applied to the seismic analysis of such three-dimensional systems as piping systems subjected to multi-excitations of earthquakes

  14. Femtosecond coherent nuclear dynamics of excited tetraphenylethylene: Ultrafast transient absorption and ultrafast Raman loss spectroscopic studies

    Science.gov (United States)

    Kayal, Surajit; Roy, Khokan; Umapathy, Siva

    2018-01-01

    Ultrafast torsional dynamics plays an important role in the photoinduced excited state dynamics. Tetraphenylethylene (TPE), a model system for the molecular motor, executes interesting torsional dynamics upon photoexcitation. The photoreaction of TPE involves ultrafast internal conversion via a nearly planar intermediate state (relaxed state) that further leads to a twisted zwitterionic state. Here, we report the photoinduced structural dynamics of excited TPE during the course of photoisomerization in the condensed phase by ultrafast Raman loss (URLS) and femtosecond transient absorption (TA) spectroscopy. TA measurements on the S1 state reveal step-wise population relaxation from the Franck-Condon (FC) state → relaxed state → twisted state, while the URLS study provides insights on the vibrational dynamics during the course of the reaction. The TA spectral dynamics and vibrational Raman amplitudes within 1 ps reveal vibrational wave packet propagating from the FC state to the relaxed state. Fourier transformation of this oscillation leads to a ˜130 cm-1 low-frequency phenyl torsional mode. Two vibrational marker bands, Cet=Cet stretching (˜1512 cm-1) and Cph=Cph stretching (˜1584 cm-1) modes, appear immediately after photoexcitation in the URLS spectra. The initial red-shift of the Cph=Cph stretching mode with a time constant of ˜400 fs (in butyronitrile) is assigned to the rate of planarization of excited TPE. In addition, the Cet=Cet stretching mode shows initial blue-shift within 1 ps followed by frequency red-shift, suggesting that on the sub-picosecond time scale, structural relaxation is dominated by phenyl torsion rather than the central Cet=Cet twist. Furthermore, the effect of the solvent on the structural dynamics is discussed in the context of ultrafast nuclear dynamics and solute-solvent coupling.

  15. Nuclear excitation function and particle emission from complex nuclei following muon capture

    International Nuclear Information System (INIS)

    Lifshitz, M.; Singer, P.

    1980-01-01

    A model for the calculation of the nuclear excitation function following muon capture in complex nuclei and of the ensuing emission is presented. The capturing nucleus is treated as consisting of quasifree nucleons moving in a momentum-dependent potential and having an effective nucleon-momentum distribution. The emission of protons, deuterons, α particles, and neutrons is calculated by considering both pre-equilibrium and compound-nucleus emission. The model accounts well for the observed charged particles emission rates from capturing nuclei over the wide range 23 < or = A < or = 209. The proton emission is shown to become mainly of pre-equilibrium nature for the heavier nuclei. The results for neutron emission are also in satisfactory agreement with experimentally measured multiplicities and spectra

  16. The Collective Vector method in nuclear and atomic physics

    Energy Technology Data Exchange (ETDEWEB)

    Bloom, S.D.

    1989-12-01

    We present a brief review of the method of the Collective Vector (CV) and its use in conjunction with the Lanczos algorithm (LA). The combination of these two ideas produces a method for contracting super-large hamiltonians (up to 10{sup 6} {times} 10{sup 6}) by factors of 1000 or more. The contracted hamiltonians, which we call quasi-hamiltonians, typically have dimensions of the order of 10{sup 2} {times} 10{sup 2} and produce corresponding quasi-spectra with associated quasi-eigenfunctions which reproduce the features of the full microscopic spectrum thru the conservation of the spectral moments. Examples of applications to both nuclear and atomic physics are given demonstrating the convergence properties of the method. The application of the LA/CV approach to the problem of modelling nuclear level densities is described and finally we discuss the possibility of conjoining new collective models of nuclear structure with the LA/CV method. 13 refs., 4 figs.

  17. Coulomb interaction in atomic and nuclear physics: Inner-Shell excitation, Coulomb dissociation of nuclei, and nuclear polarizability in electronic atoms

    International Nuclear Information System (INIS)

    Hoffmann, B.

    1984-07-01

    In three chapters different physical situations are described which have commonly the Coulomb interaction as driving force. The first two chapters study the Coulomb interactions in connection with the excitation of inner electron shells and the Coulomb excitation of nuclei in first order. In the third part on effect ofthe Coulomb interaction between electronic shell and nucleus is treated in second order (nuclear polarization), and its effect on the isotopic and isomeric shift is studied. (orig./HSI) [de

  18. Group theoretic approaches to nuclear and hadronic collective motion

    Energy Technology Data Exchange (ETDEWEB)

    Biedenharn, L.C.

    1982-01-01

    Three approaches to nuclear and hadronic collective motion are reviewed, compared and contrasted: the standard symmetry approach as typified by the Interacting Boson Model, the kinematic symmetry group approach of Gell-Mann and Tomonaga, and the recent direct construction by Buck. 50 references.

  19. Failure data collection from a Swedish nuclear power plant

    International Nuclear Information System (INIS)

    Andersson, B.; Bhattacharyya, A.; Hilding, S.

    1975-01-01

    The Swedish nuclear utilities have formed a joint working group in the field of reliability data of thermal power plants, nuclear and fossil fuelled. The primary task of the working group is to create a standard procedure of collecting failure data from the Swedish nuclear power plants in operation. The failure data will be stored in a joint data bank. A first test collection of such data has been implemented on Oskarshamn I, and the experience with this work is discussed in this report. Reliability analysis of an engineering system is based on the availability of pertinent information on the system components. Right from the beginning within the Swedish nuclear industry the consensus has been that such data can be suitably obtained by monitoring the operating power stations. This has led to a co-operative arrangement between the vendor, ASEA-ATOM and a utility, Oskarshamnsverkets Kraftgrupp AB (OKG) to utilize information from component malfunctions in the reliability analysis. The utility prepares component failure reports which are sent to the vendor for further treatment. Experience gathered to date indicates that this arrangement is effective although many persons are involved in this process of information transmittal. The present set-up is flexible enough to accommodate necessary changes in view of problems which arise now and then in monitoring a complex system like a nuclear power station. This report briefly describes the structure of the failure data collection system. The way in which the raw data collection is done in the station by the owner and the subsequent data processing by the vendor is discussed. A brief status report of the information collected since 1971 is given. It can be concluded that valuable reliability data can be obtained by monitoring component failure reports from an operating power plant. Two requirements are, however, that all the parties involved in the arrangement follow given instructions carefully and that the assumed

  20. Nuclear structure studies by means of magnetic moments of excited states

    International Nuclear Information System (INIS)

    Kaeubler, L.; Prade, H.; Schneider, L.; Brinckmann, H.F.; Stary, F.

    1981-09-01

    Experimental arrangements installed at the cyclotron U-120 and the tandem accelerator EGP-10 for the in-beam measurement of magnetic moments of excited nuclear states are discribed. The Perturbed-Angular-Distribution-method (PAD) has been used. A new evaluation method has been developed for the unique determination of the Larmor frequency from spin-procession spectra R(t) with less than half of an oscillation period between consecutive particle pulses. Magnetic moments in transitional nuclei or in nuclei near closed shells ( 103 Pd, 105 Ag, 117 Sb, 117 Te, 121 Te, 121 I, 143 Pm and 207 Bi) were measured. The results are discussed with the aim to get information about the nuclear structure of the corresponding isomeric states in connection with complex spectroscopic investigations. Therefore, the experimental values are compared to the results of model calculations (core-polarization, core-particle-coupling, Nilsson, particle-rotation-coupling or shell-model) or to the estimates on the basis of the additivity of effective magnetic moments. Single-particle aspects are discussed in connection with the magnetic moments of hsub(11/2)-, dsub(5/2)- and gsub(7/2)-neutron (ν) and proton (π) states in the nuclei 103 Pd, 117 Te, 121 Te and 143 Pm, respectively. The configurations of (π) 3 and (π)(ν) 2 -three-particle states in 105 Ag, 117 Sb, 121 I and 207 Bi could be determined using the additivity rule. The experimental magnetic moments of states in 143 Pm agree very well with the results of shell-model calculations, which have firstly been carried out also for negative-parity states in this mass region. Considering magnetic moments in 117 Te and 121 Te we could demonstrate the influence of different nuclear deformations on the magnetic moments in transitional nuclei. (author)

  1. Density profiles and collective excitations of a trapped two-component Fermi vapour

    International Nuclear Information System (INIS)

    Amoruso, M.; Meccoli, I.; Minguzzi, A.; Tosi, M.P.

    1999-08-01

    We discuss the ground state and the small-amplitude excitations of a degenerate vapour of fermionic atoms placed in two hyperfine states inside a spherical harmonic trap. An equations-of-motion approach is set up to discuss the hydrodynamic dissipation processes from the interactions between the two components of the fluid beyond mean-field theory and to emphasize analogies with spin dynamics and spin diffusion in a homogeneous Fermi liquid. The conditions for the establishment of a collisional regime via scattering against cold-atom impurities are analyzed. The equilibrium density profiles are then calculated for a two-component vapour of 40 K atoms: they are little modified by the interactions for presently relevant values of the system parameters, but spatial separation of the two components will spontaneously arise as the number of atoms in the trap is increased. The eigenmodes of collective oscillation in both the total particle number density and the concentration density are evaluated analytically in the special case of a symmetric two-component vapour in the collisional regime. The dispersion relation of the surface modes for the total particle density reduces in this case to that of a one-component Fermi vapour, whereas the frequencies of all other modes are shifted by the interactions. (author)

  2. Photo-excited charge collection spectroscopy probing the traps in field-effect transistors

    CERN Document Server

    Im, Seongil; Kim, Jae Hoon

    2013-01-01

    Solid state field-effect devices such as organic and inorganic-channel thin-film transistors (TFTs) have been expected to promote advances in display and sensor electronics. The operational stabilities of such TFTs are thus important, strongly depending on the nature and density of charge traps present at the channel/dielectric interface or in the thin-film channel itself. This book contains how to characterize these traps, starting from the device physics of field-effect transistor (FET). Unlike conventional analysis techniques which are away from well-resolving spectral results, newly-introduced photo-excited charge-collection spectroscopy (PECCS) utilizes the photo-induced threshold voltage response from any type of working transistor devices with organic-, inorganic-, and even nano-channels, directly probing on the traps. So, our technique PECCS has been discussed through more than ten refereed-journal papers in the fields of device electronics, applied physics, applied chemistry, nano-devices and materia...

  3. Excited collective states of nuclei within Bohr Hamiltonian with Tietz-Hua potential

    Science.gov (United States)

    Chabab, M.; El Batoul, A.; Hamzavi, M.; Lahbas, A.; Oulne, M.

    2017-07-01

    In this paper, we present new analytical solutions of the Bohr Hamiltonian problem that we derived with the Tietz-Hua potential, here used for describing the β -part of the nuclear collective potential plus that of the harmonic oscillator for the γ -part. Also, we proceed to a systematic comparison of the numerical results obtained with this kind of β -potential with others which are widely used in such a framework as well as with the experiment. The calculations are carried out for energy spectra and electromagnetic transition probabilities for γ -unstable and axially symmetric deformed nuclei. In the same frame, we show the effect of the shape flatness of the β -potential beyond its minimum on transition rates calculations.

  4. Excited collective states of nuclei within Bohr Hamiltonian with Tietz-Hua potential

    Energy Technology Data Exchange (ETDEWEB)

    Chabab, M.; El Batoul, A.; Lahbas, A.; Oulne, M. [Cadi Ayyad University, High Energy Physics and Astrophysics Laboratory, Faculty of Sciences Semlalia, Marrakesh (Morocco); Hamzavi, M. [University of Zanjan, Department of Physics, Zanjan (Iran, Islamic Republic of)

    2017-07-15

    In this paper, we present new analytical solutions of the Bohr Hamiltonian problem that we derived with the Tietz-Hua potential, here used for describing the β-part of the nuclear collective potential plus that of the harmonic oscillator for the γ-part. Also, we proceed to a systematic comparison of the numerical results obtained with this kind of β-potential with others which are widely used in such a framework as well as with the experiment. The calculations are carried out for energy spectra and electromagnetic transition probabilities for γ-unstable and axially symmetric deformed nuclei. In the same frame, we show the effect of the shape flatness of the β-potential beyond its minimum on transition rates calculations. (orig.)

  5. Selected topics in nuclear structure

    International Nuclear Information System (INIS)

    1994-01-01

    The collection of abstracts on selected topics in nuclear structure are given. Special attention pays to collective excitations and high-spin states of nuclei, giant resonance structure, nuclear reaction mechanisms and so on

  6. Nuclear structure studies of the neutron-rich Rubidium isotopes using Coulomb excitation

    CERN Multimedia

    Reiter, P; Blazhev, A A; Voulot, D; Meot, V H; Simpson, G S; Georgiev, G P; Gaudefroy, L; Roig, O

    We propose to study the properties of odd-mass neutron-rich rubidium isotopes by the Coulomb-excitation technique, using the Miniball array coupled to the REX-ISOLDE facility. The results from similar measurements from the recent years (e.g. for the odd-mass and the odd-odd Cu isotopes, IS435) have shown the strong potential in such measurements for gaining information both for single-particle-like and collective states in exotic nuclei. Since there is practically no experimental information for excited states in the odd-mass Rb isotopes beyond $^{93}$Rb, the present study should be able to provide new data in a region of spherical ($^{93}$Rb and $^{95}$Rb) as well as well-deformed nuclei ($^{97}$Rb and $^{99}$Rb). Of particular interest is the rapid shape change that occurs when going from $^{95}$Rb (${\\varepsilon}_{2}$=0.06) to $^{97}$Rb (${\\varepsilon}_{2}$=0.3). These results should be of significant astrophysical interest as well, due to the close proximity of the r-process path.

  7. An analytical study on excitation of nuclear-coupled thermal-hydraulic instability due to seismically induced resonance in BWR

    Energy Technology Data Exchange (ETDEWEB)

    Hirano, Masashi [Japan Atomic Energy Research Institute, Ibaraki-ken (Japan)

    1997-07-01

    This paper describes the results of a scoping study on seismically induced resonance of nuclear-coupled thermal-hydraulic instability in BWRs, which was conducted by using TRAC-BF1 within a framework of a point kinetics model. As a result of the analysis, it is shown that a reactivity insertion could occur accompanied by in-surge of coolant into the core resulted from the excitation of the nuclear-coupled instability by the external acceleration. In order to analyze this phenomenon more in detail, it is necessary to couple a thermal-hydraulic code with a three-dimensional nuclear kinetics code.

  8. Electron excitation collision strengths for positive atomic ions: a collection of theoretical data

    Energy Technology Data Exchange (ETDEWEB)

    Merts, A.L.; Mann, J.B.; Robb, W.D.; Magee, N.H. Jr.

    1980-03-01

    This report contains data on theoretical and experimental cross sections for electron impact excitation of positive atomic ions. It is an updated and corrected version of a preliminary manuscript which was used during an Atomic Data Workshop on Electron Excitation of Ions held at Los Alamos in November 1978. The current status of quantitative knowledge of collisional excitation collision strengths is shown for highly stripped ions where configuration mixing, relativistic and resonance effects may be important. The results show a reasonably satisfactory state for first-row isoelectronic ions and indicate that a considerable amount of work remains to be done for second-row and heavier ions.

  9. How to Collect National Institute of Standards and Technology (NIST) Traceable Fluorescence Excitation and Emission Spectra.

    Science.gov (United States)

    Gilmore, Adam Matthew

    2014-01-01

    Contemporary spectrofluorimeters comprise exciting light sources, excitation and emission monochromators, and detectors that without correction yield data not conforming to an ideal spectral response. The correction of the spectral properties of the exciting and emission light paths first requires calibration of the wavelength and spectral accuracy. The exciting beam path can be corrected up to the sample position using a spectrally corrected reference detection system. The corrected reference response accounts for both the spectral intensity and drift of the exciting light source relative to emission and/or transmission detector responses. The emission detection path must also be corrected for the combined spectral bias of the sample compartment optics, emission monochromator, and detector. There are several crucial issues associated with both excitation and emission correction including the requirement to account for spectral band-pass and resolution, optical band-pass or neutral density filters, and the position and direction of polarizing elements in the light paths. In addition, secondary correction factors are described including (1) subtraction of the solvent's fluorescence background, (2) removal of Rayleigh and Raman scattering lines, as well as (3) correcting for sample concentration-dependent inner-filter effects. The importance of the National Institute of Standards and Technology (NIST) traceable calibration and correction protocols is explained in light of valid intra- and interlaboratory studies and effective spectral qualitative and quantitative analyses including multivariate spectral modeling.

  10. Nuclear excitations and reaction mechanisms. Report of progress, February 1, 1975--October 31, 1975

    International Nuclear Information System (INIS)

    1975-01-01

    Progress in the following areas of research is reported: Energies of giant isoscalar monopole and quadrupole excitations, energy-weighted sum rules, the random-phase approximation, Hartree-Fock calculations, spreading widths, physical consequences of the locality of current-density commutators and current-current sum rules. Electron-hydrogen scattering using the inhomogenous equation method; variational calculation of e - + H scattering using the symmetrized channel coupling array equation; K operators and unitary approximations for the 3-body problem; approximate calculation of model (d-p) and (dd) amplitudes and cross sections; multi-step processes in direct reactions; bound state calculations using the channel coupling array theory. Methods for determining nuclear charge distributions, relativistic effects in nuclei, dispersion corrections and recoil corrections to elastic electron scattering; unitarity of elastic scattering amplitudes; low energy theorems for two-photon processes; pion-exchange contributions to the charge density; recoil effects and energy-dependent Hamiltonians; pion-exchange contributions to two-photon processes; hypervirial theorems for the Dirac equation; Coulomb energies of nuclei. Pion-nucleus scattering, diagonalization of the Δ-(nucleon-hole) configurations, doorway states and doorway dominance, calculations for 4 He, discussion of experimental results

  11. Collective state of interwall excitons on GaAs/AlGaAs double quantum wells under pulse resonant excitation

    CERN Document Server

    Larionov, A V; Hvam, J; Soerensen, K

    2002-01-01

    The time evolution and kinetics of the photoluminescence (PL) spectra of the interwall excitons under the pulse resonant excitation of the interwall excitons are studied in the GaAs/AlGaAs binary quantum well. It is established, that the collective exciton phase originates with the time delay relative to the exciting pulse (several nanoseconds), which is conditioned by the density and temperature relaxation to the equilibrium values.The origination of the collective phase of the interwall excitons is accompanied by the strong narrowing of the corresponding photoluminescence line, the superlinear growth of its intensity and large time of change in the degree of the circular polarization.The collective exciton phase originates at the temperatures < 6 K and the interwall excitons densities 3 x 10 sup 1 sup 0 cm sup - sup 2

  12. Perspectives in the theory of nuclear collective motion

    International Nuclear Information System (INIS)

    Klein, A.

    1980-01-01

    This report discusses three different subjects. The first is the development of a generalized version of the VMI (variable moment of inertia) model that ties it to the original form of the IBM (interacting boson model) and provides a possibility of fitting vibrational spectra with generalized vibrational formulas. The second is a suggestion for fitting band crossing calculations of the phenomenological type more completely than has hitherto been done into the framework of the VMI method. The third, which is the most important and far reaching, is the description f a complete mathematical method for the microscopic derivation of the IBM from a conventional shell-model Hamiltonian. In addition to elements already foreseen by previous authors, there is proposed a solution for the most important problem outstanding, not only within the framework of the IBM, but also in all previous work on boson expansion. This is the problem of actually selecting, in a general fashion, the most collective excitations. A criterion is introduced that the subspace constructed from these excitations should possess an average energy that is lower than the rest of the shell model space; the actual implementation of this criterion is explained. 8 tables, 62 references

  13. Master equations in the microscopic theory of nuclear collective dynamics

    International Nuclear Information System (INIS)

    Matsuo, M.; Sakata, F.; Marumori, T.; Zhuo, Y.

    1988-07-01

    In the first half of this paper, the authors describe briefly a recent theoretical approach where the mechanism of the large-amplitude dissipative collective motions can be investigated on the basis of the microscopic theory of nuclear collective dynamics. Namely, we derive the general coupled master equations which can disclose, in the framework of the TDHF theory, not only non-linear dynamics among the collective and the single-particle modes of motion but also microscopic dynamics responsible for the dissipative processes. In the latter half, the authors investigate, without relying on any statistical hypothesis, one possible microscopic origin which leads us to the transport equation of the Fokker-Planck type so that usefullness of the general framework is demonstrated. (author)

  14. Nuclear collective rotation in the SU3 model, 2

    International Nuclear Information System (INIS)

    Kinouchi, Shin-ichi; Kishimoto, Teruo; Kammuri, Tetsuo.

    1989-05-01

    The collective rotation of a nuclear system with the SU 3 Hamiltonian is described by the quantal dynamical nuclear field theory. An angular frequency in the Coriolis interaction of the driving Hamiltonian is replaced by a total angular momentum operator divided by the corresponding moment of inertia. We consider here the low spin states for a triaxial intrinsic configuration. The rotational effect is taken into account by using the effective quadrupole and angular momentum operators, whose expressions are different depending on whether they refer to the laboratory frame or the body-fixed one. Effective forms of the total Hamiltonian and the particle angular momentum are compared with the exact SU 3 energy and the rotor's angular momentum, respectively. In order to dissolve the disagreement for the effective operators, the perturbing interaction should be supplemented by a residual part of the quadrupole-quadrupole interaction, which restores the rotational invariance of the intrinsic Hamiltonian. (author)

  15. Collective excitations in Ni62Nb38 glass from partial scattering functions

    International Nuclear Information System (INIS)

    Syrykh, G.F.; Ivanov, A.S.; Stride, J.; Zemlyanov, M.G.

    2004-01-01

    The inelastic neutron scattering intensity, I(E,Ω), for Ni 62 Nb 38 metal glass has been measured over a wide range of scattering angles, Ω=13 deg. -120 deg., and energy transfer, E=-10-+50 meV. Three samples with the same chemical composition and different Ni isotope content have been investigated. This allowed us to reconstruct three partial inelastic scattering functions I NiNi (E,Ω), I NbNb (E,Ω), and I NiNb (E,Ω), according to the Ashcroft-Langreth formalism. The propagating excitations in a two-component amorphous alloy are the result of the superposition of three partial excitations. Each of these excitations is given by the corresponding partial atomic distribution. The 'acoustic-phonon-like' dispersion relation is observed up to Q=6.5 A -1 , which is the limit accessible in the present experiment

  16. Analysis and treatment of diametral tolerance of exciter shaft of the 650 MW nuclear power plant

    International Nuclear Information System (INIS)

    Liu Qiang

    2010-01-01

    The generator and exciter has three support connection in Qinshan II, i.e. there are two bearings for the generator rotor and one for the exciter. This structure results in difficulty to meet the standard when checking the exciter bearing's diametral tolerance. In the fifth outage of unit 2 turbo-generator in Qinshan II, the diametral tolerance failed to meet the standard. There were several reasons, such as the alignment of generator and exciter coupling, the angular moment of generator and exciter coupling bolt, the end surface condition of generator and exciter coupling, the fitting dimension of the coupling bolt hole and the sleeve in it. After analysis and screening of all factors, it was confirmed that the radical reason was the abnormal condition of the generator coupling end surface, and the problem was solved by machining the end surface. (author)

  17. Systematics of nuclear densities, deformations and excitation energies within the context of the generalized rotation-vibration model

    Energy Technology Data Exchange (ETDEWEB)

    Chamon, L.C., E-mail: luiz.chamon@dfn.if.usp.b [Departamento de Fisica Nuclear, Instituto de Fisica da Universidade de Sao Paulo, Caixa Postal 66318, 05315-970, Sao Paulo, SP (Brazil); Carlson, B.V. [Departamento de Fisica, Instituto Tecnologico de Aeronautica, Centro Tecnico Aeroespacial, Sao Jose dos Campos, SP (Brazil)

    2010-11-30

    We present a large-scale systematics of charge densities, excitation energies and deformation parameters for hundreds of heavy nuclei. The systematics is based on a generalized rotation-vibration model for the quadrupole and octupole modes and takes into account second-order contributions of the deformations as well as the effects of finite diffuseness values for the nuclear densities. We compare our results with the predictions of classical surface vibrations in the hydrodynamical approximation.

  18. Parity measurements of nuclear dipole excitations using FEL-generated gamma-rays at HI gamma S

    CERN Document Server

    Pietralla, N; Litvinenko, V N; Ahmed, M W; Tonchev, A P

    2002-01-01

    First Nuclear Resonance Fluorescence (NRF) experiments were performed at the storage ring FEL-driven High Intensity Gamma Source (HI gamma S) at the DFELL. Azimuthal NRF intensity ratios were measured around the polarized HI gamma S beam. Electric character was deduced for 18 dipole excitations in sup 1 sup 3 sup 8 Ba . The measurements demonstrate the superior performance of the HI gamma S facility in making such measurements. We report here on the performance of this set-up.

  19. Nuclear photonics at ultra-high counting rates and higher multipole excitations

    International Nuclear Information System (INIS)

    Thirolf, P. G.; Habs, D.; Filipescu, D.; Gernhäuser, R.; Günther, M. M.; Jentschel, M.; Marginean, N.; Pietralla, N.

    2012-01-01

    Next-generation γ beams from laser Compton-backscattering facilities like ELI-NP (Bucharest)] or MEGa-Ray (Livermore) will drastically exceed the photon flux presently available at existing facilities, reaching or even exceeding 10 13 γ/sec. The beam structure as presently foreseen for MEGa-Ray and ELI-NP builds upon a structure of macro-pulses (∼120 Hz) for the electron beam, accelerated with X-band technology at 11.5 GHz, resulting in a micro structure of 87 ps distance between the electron pulses acting as mirrors for a counterpropagating intense laser. In total each 8.3 ms a γ pulse series with a duration of about 100 ns will impinge on the target, resulting in an instantaneous photon flux of about 10 18 γ/s, thus introducing major challenges in view of pile-up. Novel γ optics will be applied to monochromatize the γ beam to ultimately ΔE/E∼10 −6 . Thus level-selective spectroscopy of higher multipole excitations will become accessible with good contrast for the first time. Fast responding γ detectors, e.g. based on advanced scintillator technology (e.g. LaBr 3 (Ce)) allow for measurements with count rates as high as 10 6 -10 7 γ/s without significant drop of performance. Data handling adapted to the beam conditions could be performed by fast digitizing electronics, able to sample data traces during the micro-pulse duration, while the subsequent macro-pulse gap of ca. 8 ms leaves ample time for data readout. A ball of LaBr 3 detectors with digital readout appears to best suited for this novel type of nuclear photonics at ultra-high counting rates.

  20. Nuclear power and the public: an update of collected survey research on nuclear power

    International Nuclear Information System (INIS)

    Rankin, W.L.; Melber, B.D.; Overcast, T.D.; Nealey, S.M.

    1981-12-01

    The purpose of this research was to collect, analyze, and summarize all of the nuclear power-related surveys conducted in the United States through June 1981, that we could obtain. The surveys collected were national, statewide, and areawide in scope. Slightly over 100 surveys were collected for an earlier, similar effort carried out in 1977. About 130 new surveys were added to the earlier survey data. Thus, about 230 surveys were screened for inclusion in this report. Because of space limitations, national surveys were used most frequently in this report, followed distantly by state surveys. In drawing our conclusions about public beliefs and attitudes toward nuclear power, we placed most of our confidence in survey questions that were used by national polling firms at several points in time. A summary of the research findings is presented, beginning with general attitudes toward nuclear power, followed by a summary of beliefs and attitudes about nuclear power issues, and ended by a summary of beliefs and attitudes regarding more general energy issues

  1. Nuclear power and the public: an update of collected survey research on nuclear power

    Energy Technology Data Exchange (ETDEWEB)

    Rankin, W.L.; Melber, B.D.; Overcast, T.D.; Nealey, S.M.

    1981-12-01

    The purpose of this research was to collect, analyze, and summarize all of the nuclear power-related surveys conducted in the United States through June 1981, that we could obtain. The surveys collected were national, statewide, and areawide in scope. Slightly over 100 surveys were collected for an earlier, similar effort carried out in 1977. About 130 new surveys were added to the earlier survey data. Thus, about 230 surveys were screened for inclusion in this report. Because of space limitations, national surveys were used most frequently in this report, followed distantly by state surveys. In drawing our conclusions about public beliefs and attitudes toward nuclear power, we placed most of our confidence in survey questions that were used by national polling firms at several points in time. A summary of the research findings is presented, beginning with general attitudes toward nuclear power, followed by a summary of beliefs and attitudes about nuclear power issues, and ended by a summary of beliefs and attitudes regarding more general energy issues.

  2. Fast heavy ion collisions with C{sub 60}: Collective excitation

    Energy Technology Data Exchange (ETDEWEB)

    Kadhane, Umesh [Tata Institute of Fundamental Research, Colaba, Mumbai-400005 (India); Kelkar, A.H. [Tata Institute of Fundamental Research, Colaba, Mumbai-400005 (India); Misra, D. [Tata Institute of Fundamental Research, Colaba, Mumbai-400005 (India); Kumar, Ajay [Tata Institute of Fundamental Research, Colaba, Mumbai-400005 (India); Tribedi, L.C. [Tata Institute of Fundamental Research, Colaba, Mumbai-400005 (India)]. E-mail: lokesh@tifr.res.in

    2006-11-15

    Ionization and fragmentation of C{sub 60} in collision with 5 MeV/{mu}m O{sup 6+} ions are studied using recoil ion ToF method. Relative ionization cross sections up to C{sub 60} {sup 4+} are determined. The qualitative trend for different C{sub 60} charge states was compared against simple plasmon excitation model.

  3. Pressure-induced emergence of unusually high-frequency transverse excitations in a liquid alkali metal: Evidence of two types of collective excitations contributing to the transverse dynamics at high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Bryk, Taras [Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1 Svientsitskii Street, UA-79011 Lviv (Ukraine); Lviv Polytechnic National University, 12 S. Bandera Street, UA-79013 Lviv (Ukraine); Ruocco, G. [Dipartimento di Fisica, Universita di Roma La Sapienza, 5 Piazzale Aldo Moro, I-00185 Roma (Italy); Center for Life Nano Science @Sapienza, Istituto Italiano di Tecnologia, 295 Viale Regina Elena, I-00161 Roma (Italy); Scopigno, T. [Dipartimento di Fisica, Universita di Roma La Sapienza, 5 Piazzale Aldo Moro, I-00185 Roma (Italy); IPCF-CNR, c/o Universita di Roma La Sapienza, 5 Piazzale Aldo Moro, I-00185 Roma (Italy); Seitsonen, Ari P. [Département de Chimie, Université de Zurich, Winterthurerstrasse 190, CH-8057 Zürich (Switzerland); Département de Chimie, École Normale Supérieure, 24 rue Lhomond, F-75005 Paris (France)

    2015-09-14

    Unlike phonons in crystals, the collective excitations in liquids cannot be treated as propagation of harmonic displacements of atoms around stable local energy minima. The viscoelasticity of liquids, reflected in transition from the adiabatic to elastic high-frequency speed of sound and in absence of the long-wavelength transverse excitations, results in dispersions of longitudinal (L) and transverse (T) collective excitations essentially different from the typical phonon ones. Practically, nothing is known about the effect of high pressure on the dispersion of collective excitations in liquids, which causes strong changes in liquid structure. Here dispersions of L and T collective excitations in liquid Li in the range of pressures up to 186 GPa were studied by ab initio simulations. Two methodologies for dispersion calculations were used: direct estimation from the peak positions of the L/T current spectral functions and simulation-based calculations of wavenumber-dependent collective eigenmodes. It is found that at ambient pressure, the longitudinal and transverse dynamics are well separated, while at high pressures, the transverse current spectral functions, density of vibrational states, and dispersions of collective excitations yield evidence of two types of propagating modes that contribute strongly to transverse dynamics. Emergence of the unusually high-frequency transverse modes gives evidence of the breakdown of a regular viscoelastic theory of transverse dynamics, which is based on coupling of a single transverse propagating mode with shear relaxation. The explanation of the observed high-frequency shift above the viscoelastic value is given by the presence of another branch of collective excitations. With the pressure increasing, coupling between the two types of collective excitations is rationalized within a proposed extended viscoelastic model of transverse dynamics.

  4. Onset of collectivity in $^{96,98}$Sr studied via Coulomb excitation

    CERN Document Server

    Clement, E; Dijon, A; de France, G; Bastin, B; Blazhev, A; Bree, N; Butler, P; Delahaye, P; Ekstrom, A; Georgiev, G; Hasan, N; Iwanicki, J; Jenkins, D; Korten, W; Larsen, A C; Ljungvall, J; Moschner, K; Napiorkowski, P; Pakarinen, J; Petts, A; Renstrom, T; Seidlitz, M; Siem, S; Sotty, C; Srebrny, J; Stefanescu, I; Tveten, G M; Van de Walle, J; Warr, N; Wrzosek-Lipska, K; Zielinska, M; Bauer, C; Bruyneel, B; Butterworth, J; Fitzpatrick, C; Fransen, C; GernhäUser, R; Hess, H; Lutter, R; Marley, P; Reiter, P; Siebeck, B; Vermeulen, M; Wiens, A; De Witte, H

    2014-01-01

    A rapid onset of quadrupole deformation is known to occur around the neutron number 60 in the neutron-rich Zr and Sr isotopes. This shape change has made the neutron-rich A = 100 region an active area of experimental and theoretical studies for many decades now. We report in this contribution new experimental results in the neutron rich 96,98Sr investigated by safe Coulomb excitation of radioactive beams at the REX-ISOLDE facility, CERN. Reduced transition probabilities and spectroscopic quadrupole moments have been extracted from the differential Coulomb excitation cross section supporting the scenario of shape coexistence/change at N=60. Future perspectives are presented including the recent experimental campaign performed at ILL-Grenoble.

  5. Onset of collectivity in 96,98Sr studied via Coulomb excitation

    Directory of Open Access Journals (Sweden)

    Clément E.

    2014-03-01

    Full Text Available A rapid onset of quadrupole deformation is known to occur around the neutron number 60 in the neutron-rich Zr and Sr isotopes. This shape change has made the neutron-rich A = 100 region an active area of experimental and theoretical studies for many decades now. We report in this contribution new experimental results in the neutron rich 96,98Sr investigated by safe Coulomb excitation of radioactive beams at the REX-ISOLDE facility, CERN. Reduced transition probabilities and spectroscopic quadrupole moments have been extracted from the differential Coulomb excitation cross section supporting the scenario of shape coexistence/change at N=60. Future perspectives are presented including the recent experimental campaign performed at ILL-Grenoble.

  6. Local excitation and local collection of photocurrent in thin-film polycrystalline photovoltaic devices

    Science.gov (United States)

    Zhitenev, Nikolai; Yoon, Heayoung; Leite, Marina; Lee, Youngmin; Ko, Sarah; Zhao, Yue; Gianfrancesco, Anthony; Haney, Paul; Talin, Alec

    2013-03-01

    The power conversion efficiency of commercial solar modules based on thin-film chalcogenide materials is well below the theoretical limits. To understand the underlying physical mechanisms limiting the efficiency, we investigate local photovoltaic properties isolating the difference between the grain bulk (0.5-2 mkm in size) and the grain boundary in CdTe absorber. Local current-voltage measurements are performed using nano-contacts in conjunction with local electron-hole pairs generation comparing multiple injection techniques. First, the carriers are excited using variable energy electron beam enabling measurements with a spatial resolution down to 20 nm. Second, we have developed a novel approach for high-resolution and high-throughput photocurrent imaging downconverting electron beam into a near-field optical source using a thin film (<50 nm) of phosphors. The electron beam is fully absorbed in the phosphors layer, and the cathodoluminescence is used as a local photon source. Third, we generate carriers using a near-filed optical microscope varying the excitation wavelength. The results show that, in a well-optimized material, a large fraction of grain boundaries displays higher photocurrent as compared to grain bulk effectively serving as a three-dimensional distributed photocurrent collector.

  7. A Folded Excited State of Ligand-Free Nuclear Coactivator Binding Domain (NCBD) Underlies Plasticity in Ligand Recognition

    DEFF Research Database (Denmark)

    Kjaergaard, Magnus; Andersen, Lisbeth; Nielsen, Lau Dalby

    2013-01-01

    Intrinsically disordered proteins are renowned for their structural plasticity when they undergo coupled folding and binding to partner proteins. The nuclear coactivator binding domain of CBP is a remarkable example of this adaptability as it folds into two different conformations depending...... experience conformational exchange. The dispersion data can be described by a global two-state exchange process between a ground state and an excited state populated to 8%. The three helices are still folded in the excited state but have a different packing from the ground state; the contact between helices...... with that of NCBD in complex with the ligand IRF-3. The energy landscape of this domain is thus proposed to resemble the fold-switching proteins that have two coexisting native states, which may serve as a starting point for binding via conformational selection....

  8. Nuclei far from stability. Individual and collective excitations at low energy

    International Nuclear Information System (INIS)

    Meyer, M.

    1984-01-01

    The low energy structure of exotic nuclei is discussed in terms of self-consistent microscopic models. The experimental striking features of the spectroscopy of these nuclei are briefly surveyed and the schematic steps performed to obtain from effective N-N interactions their spectroscopic properties are presented. Their saturation and deformation properties are given by the Hartree-Fock approximation (HF). Then it is shown how to describe the dynamics of even-even exotic nuclei excited states by solving the complete Bohr Hamiltonian, built microscopically using the HF approximation and the adiabatic limit (and its derivatives) of the time-dependent HF approximation (ATDHF). The structure of odd and doubly odd nuclei is discussed in the framework of the unified model, ie the microscopic rotor + quasiparticles model. Finally possible future directions of experimental research concerning exotic nuclei are described and improvements or new theoretical approaches discussed [fr

  9. Low energy nuclear spin excitations in Ho metal investigated by high resolution neutron spectroscopy.

    Science.gov (United States)

    Chatterji, Tapan; Jalarvo, Niina

    2013-04-17

    We have investigated the low energy excitations in metallic Ho by high resolution neutron spectroscopy. We found at T = 3 K clear inelastic peaks in the energy loss and energy gain sides, along with the central elastic peak. The energy of this low energy excitation, which is 26.59 ± 0.02 μeV at T = 3 K, decreased continuously and became zero at TN ≈ 130 K. By fitting the data in the temperature range 100-127.5 K with a power law we obtained the power-law exponent β = 0.37 ± 0.02, which agrees with the expected value β = 0.367 for a three-dimensional Heisenberg model. Thus the energy of the low energy excitations can be associated with the order parameter.

  10. Nuclear excitations and reaction mechanisms. Progress report, 1 August-31 July 1984

    International Nuclear Information System (INIS)

    Fallieros, S.; Levin, F.S.

    1984-01-01

    This progress report describes activities of the Nuclear Theory group at Brown University during the period 1 August 1983 to 31 July 1984. Completed and ongoing research include various theoretical and numerical studies of few-particle systems, nuclear reaction models, nuclear electroexcitation and photon scattering from nuclei. In addition, research on atomic and molecular structure has essentially been concluded and no further DOE-supported research in this area is anticipated

  11. Third international radioecological conference. The fate of spent nuclear fuel: problems and reality. Abstracts collection

    International Nuclear Information System (INIS)

    1996-01-01

    In the book there are abstracts collection of the third International radioecological conference 'The fate of spent nuclear fuel: problems and reality' (June, 22-27, 1996, Krasnoyarsk, Russia) and International workshop meeting 'Defence nuclear waste disposal in Russia'. In the collection there are materials concerning the problems of technology, economics, ecology and safety of two types of nuclear cycle as well as the problems of health of population living near nuclear ojects and on contaminated territories

  12. Nuclear matter kinetic coefficients and damping of finite nuclear collective modes

    International Nuclear Information System (INIS)

    Toledo Piza, A.F.R. de.

    1986-06-01

    By carrying the general description of one-body observables beyond the mean-field approximation, those correlation terms responsible for Kinetic phenomena and those involved in the renormalization of the G-matrix mean-field in finite nuclei are identified. A Kinetic equation for the one-body density is obtained. Estimates for transport coefficients and for the damping of zero sound are obtained which point to the inadequacy of hydrodynamical descriptions of collective nuclear modes and indicate that collisional damping in large nuclei may account for one or a few tenths of the observed widths. (S.D.) [pt

  13. nfluence of the nuclear part of the nuclei interaction potential to the mass yields of fragments from fission of highly-excited nuclei

    Directory of Open Access Journals (Sweden)

    V. Yu. Denisov

    2017-11-01

    Full Text Available The influence for various parameterizations of the nuclear part of the interaction potential to the mass yields of fission fragments of highly excited nuclei for the reaction α+197Au → fission was studied. It is shown that using of various nuclear potentials leads to small changes in the yields of fission fragments of the nuclei.

  14. Multiple phonon excitation in nuclei

    International Nuclear Information System (INIS)

    Chomaz, Ph.; Frascaria, N.

    1994-01-01

    The studies of multiphonon excitations in nuclei are reviewed both from the theoretical and experimental points of view. The presence of giant resonances in nuclei is described in the framework of macroscopic and microscopic models and the relative merits of different probes to excite such states are illustrated. The existence of giant resonances built on excited states is stressed. An exhaustive description of the theoretical estimates of the properties of the multiphonon states is presented. The theory predicts that such multiple collective excitations should closely follow a harmonic pattern. Recent experimental results on the double giant dipole resonance using the (π + π - ) double charge exchange reaction are shown. The status of the search for isoscalar multiphonon excitations by means of the strong nuclear potential produced by heavy ions is presented. Conclusions are drawn and new prospects are discussed. (authors) 293 refs., 67 figs., 8 tabs

  15. Hyperfine structure in 229gTh3+ as a probe of the 229gTh→ 229mTh nuclear excitation energy.

    Science.gov (United States)

    Beloy, K

    2014-02-14

    We identify a potential means to extract the 229gTh→ 229mTh nuclear excitation energy from precision microwave spectroscopy of the 5F(5/2,7/2) hyperfine manifolds in the ion 229gTh3+. The hyperfine interaction mixes this ground fine structure doublet with states of the nuclear isomer, introducing small but observable shifts to the hyperfine sublevels. We demonstrate how accurate atomic structure calculations may be combined with the measurement of the hyperfine intervals to quantify the effects of this mixing. Further knowledge of the magnetic dipole decay rate of the isomer, as recently reported, allows an indirect determination of the nuclear excitation energy.

  16. Kinetic theory of collective excitations and damping in Bose-Einstein condensed gases

    NARCIS (Netherlands)

    Al Khawaja, U.; Stoof, H.T.C.

    2000-01-01

    We calculate the frequencies and damping rates of the low-lying collective modes of a Bose-Einstein condensed gas at nonzero temperature. We use a complex nonlinear Schrödinger equation to determine the dynamics of the condensate atoms, and couple it to a Boltzmann equation for the noncondensate

  17. How nuclear data collected for medical radionuclides production could constrain nuclear codes

    Science.gov (United States)

    Guertin, Arnaud; Duchemin, Charlotte; Fardin, Arnaud; Guigot, Corentin; Nigron, Etienne; Remy, Charlotte; Haddad, Férid; Michel, Nathalie; Métivier, Vincent

    2017-09-01

    The aim of this article is to give the status of nuclear data collected in the framework of the production of innovative radionuclides for therapy and diagnosis applications in collaboration with the GIP ARRONAX, which possesses a multi-particle high energy cyclotron, and to show constrains that can be put on nuclear codes. In order to assess the cross section of a given production route, experiments have been carried out using the stacked-foil technique and gamma-spectroscopy for a set of radionuclides of medical interest: photon (Tc-99m) and positon (Sc-44g) emitters for diagnosis, electron (Re-186g, Tb-155, Sn-117m) and alpha particle (Th-226, Ra-233, Bi-213) emitters for therapeutic applications. A systematic comparison has been performed between the results from the TALYS code (version 1.6) and the large set of data collected using different projectiles (proton, deuteron and alpha particle) from few MeV up to 70 MeV and covering a wide range of target masses. A better overall agreement with our experimental data has been obtained with a combination of models already included in the TALYS code differing from the default one.

  18. A study of the fluorescence of the rare gases excited by nuclear particles. Use of the principle for the detection of nuclear radiation by scintillation

    International Nuclear Information System (INIS)

    Koch, L.

    1959-12-01

    In the first part is studied the properties of atoms excited by the passage of α particles through the various rare gases at atmospheric pressure. A spectral analysis of the emitted light showed that certain impurities play an important part in producing the fluorescence, and it has led to the conclusion that the light emission contains at least two components - one very short - lived due to the direct deexcitation of the rare gas, the other relatively slower due to the energy transfers to the impurity. The measurement of the life-time of the excited states has confirmed this foregoing hypothesis, the rapid part of the impulse is extremely short: less than 2,25.10 -9 s in the case of xenon; the slower part has a life-time depending directly on the nitrogen concentration, nitrogen being the impurity giving the largest effect in all cases. The study of rare gases under the influence of an electric field has made it possible to show that the amount of light produced by an α particle can be multiplied (by 60, for example, in a field of 600 V:cm) so that the luminescent efficiency is greater than in the case of INaTI. In the second part the characteristics of the rare gases acting as scintillators is examined, the most important property being the absence of fluorescence saturation when the intensity of the excitation incident on the gas is very large. This, together with the very short time of scintillation has made it possible to study a certain number of nuclear physical applications (heavy particle energy-measurements, kinetic studies on nuclear reactors, neutron spectroscopy). (author) [fr

  19. Measurements of octupole collectivity in Rn and Ra nuclei using Coulomb excitation

    CERN Document Server

    We propose to exploit the unique capability of HIE-ISOLDE to provide post-accelerated $^{221,222}$Rn and $^{222,226,228}$Ra ion beams for the study of octupole collectivity in these nuclei. We will measure E3 transition moments in $^{222}$Rn and $^{222,226,228}$Ra in order to fully map out the variation in E3 strength in the octupole mass region with Z$\\thicksim$88 and N$\\thicksim$134. This will validate model calculations that predict different behaviour as a function of N. We will also locate the position of the parity doublet partner of the ground state in $^{221}$Rn, in order to test the suitability of odd-A radon isotopes for EDM searches.

  20. Nuclear excitations and reaction mechanisms. Progress report, 1 November 1979-30 September 1980

    International Nuclear Information System (INIS)

    1980-01-01

    Among the topics investigated were the following: photon scattering and consistency condition between seagull quadrupole terms and the absorption sum rule; Raman scattering to negative-parity states; nonlocal terms due to exchange and retardation effects in charge-transfer reactions; consistency and meaning of various approximate channel coupling array equations; derivation of equations used in empirical nuclear reaction analyses; multicluster, n-particle scattering theory; converged molecular bound state calculations; consistency of approximate channel coupling array equations; derivations of equations used in empirical nuclear reaction analyses; and WKB-type approximation in angular momenta for central potentials. References to publications are given

  1. Two-photon excitation with pico-second fluorescence lifetime imaging to detect nuclear association of flavanols

    Energy Technology Data Exchange (ETDEWEB)

    Mueller-Harvey, Irene, E-mail: i.mueller-harvey@reading.ac.uk [Chemistry and Biochemistry Laboratory, Food Production and Quality Research Division, School of Agriculture, Policy and Development, University of Reading, P O Box 236, Reading RG6 6AT (United Kingdom); Feucht, Walter, E-mail: walter.feucht@gmail.com [Department of Plant Sciences, Technical University of Munich (TUM), Wissenschaftszentrum Weihenstephan (WZW), D-85354 Freising (Germany); Polster, Juergen, E-mail: j.polster@wzw.tum.de [Department of Physical Biochemistry, Technical University of Munich (TUM), Wissenschaftszentrum Weihenstephan (WZW), D-85354 Freising (Germany); Trnkova, Lucie, E-mail: lucie.trnkova@uhk.cz [University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 50003 Hradec Kralove (Czech Republic); Burgos, Pierre, E-mail: pierre.burgos@stfc.ac.uk [Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell-Oxford, Didcot, Oxfordshire, OX11 0QX (United Kingdom); Parker, Anthony W., E-mail: tony.parker@stfc.ac.uk [Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell-Oxford, Didcot, Oxfordshire, OX11 0QX (United Kingdom); Botchway, Stanley W., E-mail: stan.botchway@stfc.ac.uk [Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell-Oxford, Didcot, Oxfordshire, OX11 0QX (United Kingdom)

    2012-03-16

    is significant nuclear absorption of flavanols. This advanced imaging using two-photon excitation and biophysical techniques described here will prove valuable for probing the intracellular trafficking and functions of flavanols, such as EGCG, which is the major flavanol of green tea.

  2. Collective excitations of a hot anisotropic QCD medium with the Bhatnagar-Gross-Krook collisional kernel within an effective description

    Science.gov (United States)

    Kumar, Avdhesh; Jamal, M. Yousuf; Chandra, Vinod; Bhatt, Jitesh R.

    2018-02-01

    Collective modes of an anisotropic hot QCD medium have been studied within the semiclassical transport theory employing the Bhatnagar-Gross-Krook (BGK) collisional kernel. The modeling of the isotropic medium is primarily based on a recent quasiparticle description of a hot QCD equation of state where the medium effects have been encoded in effective gluon and quark/antiquark momentum distributions that posses nontrivial energy dispersions. The anisotropic distribution functions are obtained in a straightforward way by stretching or squeezing the isotropic ones along one of the directions. The gluon self-energy is computed using these distribution functions in a linearized transport equation with the BGK collisional kernel. Further, the tensor decomposition of gluon self-energy leads to the structure functions which eventually controls the dispersion relations and the collective mode structure of the medium. It has been seen that both the medium effects and collisions induce appreciable modifications to the collective modes or the plasma excitations in the hot QCD medium.

  3. The effect of a neutrino magnetic moment on nuclear excitation processes

    International Nuclear Information System (INIS)

    Dodd, A.C.; Papageorgiu, E.; Ranfone, S.

    1991-01-01

    We discuss the sensitivity of magnetic transitions in nuclei like 12 C, to a small neutrino magnetic moment, and its implications for current and future experiments. We also point out that coherent neutrino-nuclear elastic scattering in low-temperature detectors, might improve the present laboratory bounds on the neutrino magnetic moment by an order of magnitude. (orig.)

  4. Collective phenomena in non-central nuclear collisions

    International Nuclear Information System (INIS)

    Voloshin, Sergei A.; Poskanzer, Arthur M.; Snellings, Raimond

    2008-01-01

    Recent developments in the field of anisotropic flow in nuclear collision are reviewed. The results from the top AGS energy to the top RHIC energy are discussed with emphasis on techniques, interpretation, and uncertainties in the measurements

  5. An historical collection of papers on nuclear thermal propulsion

    Science.gov (United States)

    The present volume of historical papers on nuclear thermal propulsion (NTP) encompasses NTP technology development regarding solid-core NTP technology, advanced concepts from the early years of NTP research, and recent activities in the field. Specific issues addressed include NERVA rocket-engine technology, the development of nuclear rocket propulsion at Los Alamos, fuel-element development, reactor testing for the Rover program, and an overview of NTP concepts and research emphasizing two decades of NASA research. Also addressed are the development of the 'nuclear light bulb' closed-cycle gas core and a demonstration of a fissioning UF6 gas in an argon vortex. The recent developments reviewed include the application of NTP to NASA's Lunar Space Transportation System, the use of NTP for the Space Exploration Initiative, and the development of nuclear rocket engines in the former Soviet Union.

  6. Nuclear power and the public: analysis of collected survey research

    International Nuclear Information System (INIS)

    Melber, B.D.; Nealey, S.M.; Hammersla, J.; Rankin, W.L.

    1977-11-01

    This executive summary highlights the major findings of a comprehensive synthesis and analysis of over 100 existing surveys dealing with public attitudes toward nuclear power issues. Questions of immediate policy relevance to the nuclear debate are posed and answered on the basis of these major findings. For each issue area, those sections of the report in which more-detailed discussion and presentation of relevant data may be found are indicated

  7. Nuclear power and the public: analysis of collected survey research

    Energy Technology Data Exchange (ETDEWEB)

    Melber, B.D.; Nealey, S.M.; Hammersla, J.; Rankin, W.L.

    1977-11-01

    This executive summary highlights the major findings of a comprehensive synthesis and analysis of over 100 existing surveys dealing with public attitudes toward nuclear power issues. Questions of immediate policy relevance to the nuclear debate are posed and answered on the basis of these major findings. For each issue area, those sections of the report in which more-detailed discussion and presentation of relevant data may be found are indicated.

  8. Determination of lifetimes of nuclear excited states using the Recoil Distance Doppler Shift Method in combination with magnetic spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Doncel, M. [Universidad de Salamanca, Laboratorio de Radiaciones Ionizantes, Salamanca (Spain); Royal Institute of Technology, Department of Physics, Stockholm (Sweden); University of Liverpool, Department of Physics, Oliver Lodge Laboratory, Liverpool (United Kingdom); Gadea, A. [CSIC-University of Valencia, Istituto de Fisica Corpuscular, Valencia (Spain); Valiente-Dobon, J.J. [INFN, Laboratori Nazionali di Legnaro, Legnaro (Italy); Quintana, B. [Universidad de Salamanca, Laboratorio de Radiaciones Ionizantes, Salamanca (Spain); Modamio, V. [INFN, Laboratori Nazionali di Legnaro, Legnaro (Italy); University of Oslo, Oslo (Norway); Mengoni, D. [Dipartimento di Fisica e Astronomia, Universita di Padova, Padova (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Padova, Padova (Italy); Moeller, O.; Pietralla, N. [Technische Universitaet Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); Dewald, A. [Institut fuer Kernphysik, Universitaet Koeln (Germany)

    2017-10-15

    The current work presents the determination of lifetimes of nuclear excited states using the Recoil Distance Doppler Shift Method, in combination with spectrometers for ion identification, normalizing the intensity of the peaks by the ions detected in the spectrometer as a valid technique that produces results comparable to the ones obtained by the conventional shifted-to-unshifted peak ratio method. The technique has been validated using data measured with the γ-ray array AGATA, the PRISMA spectrometer and the Cologne plunger setup. In this paper a test performed with the AGATA-PRISMA setup at LNL and the advantages of this new approach with respect to the conventional Recoil Distance Doppler Shift Method are discussed. (orig.)

  9. Prompt muon-induced fission: A probe for nuclear friction in large-amplitude collective motion

    International Nuclear Information System (INIS)

    Oberacker, V.E.; Umar, A.S.; Wells, J.C.; Strayer, M.R.; Maruhn, J.A.; Reinhard, P.G.

    1998-01-01

    Excited muonic atoms in the actinide region may induce prompt fission by inverse internal conversion, i.e. the excitation energy of the muonic atom is transferred to the nucleus. The authors solve the time dependent Dirac equation for the muonic spinor wave function in the Coulomb field of the fissioning nucleus on a 3-dimensional lattice and demonstrate that the muon attachment probability to the light fission fragment is a measure of the nuclear energy dissipation between the outer fission barrier and the scission point

  10. Direct observation of low energy nuclear spin excitations in HoCrO3 by high resolution neutron spectroscopy.

    Science.gov (United States)

    Chatterji, T; Jalarvo, N; Kumar, C M N; Xiao, Y; Brückel, Th

    2013-07-17

    We have investigated low energy nuclear spin excitations in the strongly correlated electron compound HoCrO3. We observe clear inelastic peaks at E = 22.18 ± 0.04 μeV in both energy loss and gain sides. The energy of the inelastic peaks remains constant in the temperature range 1.5-40 K at which they are observed. The intensity of the inelastic peak increases at first with increasing temperature and then decreases at higher temperatures. The temperature dependence of the energy and intensity of the inelastic peaks is very unusual compared to that observed in other Nd, Co, V and also simple Ho compounds. Huge quasielastic scattering appears at higher temperatures presumably due to the fluctuating electronic moments of the Ho ions that get increasingly disordered at higher temperatures. The strong quasielastic scattering may also originate in the first Ho crystal-field excitations at about 1.5 meV.

  11. TDHF and fluid dynamics of nuclear collective motions

    International Nuclear Information System (INIS)

    Di Nardo, M.; Di Toro, M.; Giansiracusa, G.; Lombardo, U.; Russo, G.

    1983-01-01

    The nuclear fluid dynamical equations are derived from a mean field description of the nuclear dynamics. Simple approximate solutions, corresponding to generalized scaling modes, are worked out for rotations and vibrations, with the evaluation of inertial parameters and flow patterns. Giant resonances are shown to be quite well described within an irrotational ansatz, which is equivalent to a lowest multipoles (up to lsub(max)=2) distortion of the momentum distribution. The physical meaning of a higher order truncation of the TDHF-Fluid-Dynamics chain is finally discussed with its implication on low lying states and on some description of the Landau damping. (author)

  12. Evolution of collectivity in nuclei

    International Nuclear Information System (INIS)

    Muralithar, S.

    2016-01-01

    Nuclear structure studies provide opportunity to understand various modes of excitations and shapes of nucleus as a function of angular momentum, excitation energy and iso-spin. Single particle and collective excitations keep competing and give rise to interesting structures. Phenomena namely back bending, band termination, shape co-existence, rotational bands with different configurations and octupole correlation were reported using gamma ray spectroscopy method. Above nuclear phenomena were studied using Gamma detector array (GDA), Plunger, Heavy Ion Recoil Analyser GDA, Indian National Gamma Array - HlRA at IUAC by various users. Some examples of evolution of collectivity in nuclear structure studies carried out will be presented. (author)

  13. Doping Dependence of Collective Spin and Orbital Excitations in the Spin-1 Quantum Antiferromagnet La2 -xSrxNiO4 Observed by X Rays

    Science.gov (United States)

    Fabbris, G.; Meyers, D.; Xu, L.; Katukuri, V. M.; Hozoi, L.; Liu, X.; Chen, Z.-Y.; Okamoto, J.; Schmitt, T.; Uldry, A.; Delley, B.; Gu, G. D.; Prabhakaran, D.; Boothroyd, A. T.; van den Brink, J.; Huang, D. J.; Dean, M. P. M.

    2017-04-01

    We report the first empirical demonstration that resonant inelastic x-ray scattering (RIXS) is sensitive to collective magnetic excitations in S =1 systems by probing the Ni L3 edge of La2 -xSrxNiO4 (x =0 , 0.33, 0.45). The magnetic excitation peak is asymmetric, indicating the presence of single and multi-spin-flip excitations. As the hole doping level is increased, the zone boundary magnon energy is suppressed at a much larger rate than that in hole doped cuprates. Based on the analysis of the orbital and charge excitations observed by RIXS, we argue that this difference is related to the orbital character of the doped holes in these two families. This work establishes RIXS as a probe of fundamental magnetic interactions in nickelates opening the way towards studies of heterostructures and ultrafast pump-probe experiments.

  14. Doping Dependence of Collective Spin and Orbital Excitations in the Spin-1 Quantum Antiferromagnet La_{2-x}Sr_{x}NiO_{4} Observed by X Rays.

    Science.gov (United States)

    Fabbris, G; Meyers, D; Xu, L; Katukuri, V M; Hozoi, L; Liu, X; Chen, Z-Y; Okamoto, J; Schmitt, T; Uldry, A; Delley, B; Gu, G D; Prabhakaran, D; Boothroyd, A T; van den Brink, J; Huang, D J; Dean, M P M

    2017-04-14

    We report the first empirical demonstration that resonant inelastic x-ray scattering (RIXS) is sensitive to collective magnetic excitations in S=1 systems by probing the Ni L_{3} edge of La_{2-x}Sr_{x}NiO_{4} (x=0, 0.33, 0.45). The magnetic excitation peak is asymmetric, indicating the presence of single and multi-spin-flip excitations. As the hole doping level is increased, the zone boundary magnon energy is suppressed at a much larger rate than that in hole doped cuprates. Based on the analysis of the orbital and charge excitations observed by RIXS, we argue that this difference is related to the orbital character of the doped holes in these two families. This work establishes RIXS as a probe of fundamental magnetic interactions in nickelates opening the way towards studies of heterostructures and ultrafast pump-probe experiments.

  15. In search of high density collective phenomena in nuclear collision

    International Nuclear Information System (INIS)

    Gyulassy, M.

    1979-06-01

    The progress made toward uncovering signatures of collective phenomena is reviewed. Elements of the basic reaction mechanism leading to a complex background are first discussed. Possible hints of collective phenomena in proton and pion single and double inclusive spectra as well as π - multiplicity data are then described. 6 figures, 2 tables

  16. Peaceful Uses of Nuclear Energy: A Collection of Speeches

    Science.gov (United States)

    Seaborg, Glenn T.

    1970-07-01

    It is now a quarter of a century since nuclear energy was introduced to the public. Its introduction was made in the most dramatic, but unfortunately in the most destructive way - through the use of a nuclear weapon. Since that introduction enormous strides have been made in developing the peaceful applications of this great and versatile force. Because these strides have always been overshadowed by the focusing of public attention on the military side of the atom, the public has never fully understood or appreciated the gains and status of the peaceful atom. This booklet is an attempt to correct, in some measure, this imbalance in public information and attitude. It is a compilation of remarks, and excerpts of remarks, that I [Seaborg] have made in recent years in an effort to bring to the public the story of the remarkable benefits the peaceful atom has to offer man. This is a story that grows with the development and progress of the peaceful atom. It must be told so that we can learn to use the power of nuclear energy wisely and through this use help to build a world in which the military applications of the atom will never again be a threat to mankind.

  17. Nonlinear δf particle simulations of collective excitations and energy-anisotropy instabilities in high-intensity bunched beams

    Directory of Open Access Journals (Sweden)

    Hong Qin

    2007-06-01

    Full Text Available Collective effects with strong coupling between the longitudinal and transverse dynamics are of fundamental importance for applications of high-intensity bunched beams. The self-consistent Vlasov-Maxwell equations are applied to high-intensity finite-length charge bunches, and a generalized δf particle simulation algorithm is developed for bunched beams with or without energy anisotropy. The nonlinear δf method exhibits minimal noise and accuracy problems in comparison with standard particle-in-cell simulations. Systematic studies are carried out under conditions corresponding to strong 3D nonlinear space-charge forces in the beam frame. For charge bunches with isotropic energy, finite bunch-length effects are clearly evident by the fact that the spectra for an infinitely long coasting beam and a nearly spherical charge bunch have strong similarities, whereas the spectra have distinctly different features when the bunch length is varied between these two limiting cases. For bunched beams with anisotropic energy, there exists no exact kinetic equilibrium because the particle dynamics do not conserve transverse energy and longitudinal energy separately. A reference state in approximate dynamic equilibrium has been constructed theoretically, and a quasi-steady state has been established in the simulations for the anisotropic case. Collective excitations relative to the reference state have been simulated using the generalized δf algorithm. In particular, the electrostatic Harris instability driven by strong energy anisotropy is investigated for a finite-length charge bunch. The observed growth rates are larger than those obtained for infinitely long coasting beams. However, the growth rate decreases for increasing bunch length to a value similar to the case of a long coasting beam. For long bunches, the instability is axially localized symmetrically relative to the beam center, and the characteristic wavelength in the longitudinal direction is

  18. Theoretical research in nuclear collective motion. Progress report

    International Nuclear Information System (INIS)

    1984-01-01

    Progress is summarized on the following research projects: generalized density matrix method, large amplitude collective motion, boson mappings for the Interacting Boson Model, and semi-classical method for testing IBM hypothesis

  19. Hand held data collection and monitoring system for nuclear facilities

    Science.gov (United States)

    Brayton, D.D.; Scharold, P.G.; Thornton, M.W.; Marquez, D.L.

    1999-01-26

    Apparatus and method is disclosed for a data collection and monitoring system that utilizes a pen based hand held computer unit which has contained therein interaction software that allows the user to review maintenance procedures, collect data, compare data with historical trends and safety limits, and input new information at various collection sites. The system has a means to allow automatic transfer of the collected data to a main computer data base for further review, reporting, and distribution purposes and uploading updated collection and maintenance procedures. The hand held computer has a running to-do list so sample collection and other general tasks, such as housekeeping are automatically scheduled for timely completion. A done list helps users to keep track of all completed tasks. The built-in check list assures that work process will meet the applicable processes and procedures. Users can hand write comments or drawings with an electronic pen that allows the users to directly interface information on the screen. 15 figs.

  20. A photosynthetic-plasmonic-voltaic cell: Excitation of photosynthetic bacteria and current collection through a plasmonic substrate

    Science.gov (United States)

    Samsonoff, Nathan; Ooms, Matthew D.; Sinton, David

    2014-01-01

    Excitation of photosynthetic biofilms using surface-confined evanescent light fields enables energy dense photobioreactors, while electrode-adhered biofilms can provide electricity directly. Here, we demonstrate concurrent light delivery and electron transport through a plasmonically excited metal film. Biofilms of cyanobacterium Synechococcus bacillaris on 50-nm gold films are excited via the Kretschmann configuration at λ = 670 nm. Cells show light/dark response to plasmonic excitation and grow denser biofilms, closer to the electrode surface, as compared to the direct irradiated case. Directly irradiated biofilms produced average electrical powers of 5.7 μW/m2 and plasmonically excited biofilms produced average electrical powers of 5.8 μW/m2, with individual biofilms producing as much as 12 μW/m2.

  1. A photosynthetic-plasmonic-voltaic cell: Excitation of photosynthetic bacteria and current collection through a plasmonic substrate

    Energy Technology Data Exchange (ETDEWEB)

    Samsonoff, Nathan; Ooms, Matthew D.; Sinton, David [Department of Mechanical and Industrial Engineering, and Institute for Sustainable Energy, University of Toronto, Toronto M5S 3G8 (Canada)

    2014-01-27

    Excitation of photosynthetic biofilms using surface-confined evanescent light fields enables energy dense photobioreactors, while electrode-adhered biofilms can provide electricity directly. Here, we demonstrate concurrent light delivery and electron transport through a plasmonically excited metal film. Biofilms of cyanobacterium Synechococcus bacillaris on 50-nm gold films are excited via the Kretschmann configuration at λ = 670 nm. Cells show light/dark response to plasmonic excitation and grow denser biofilms, closer to the electrode surface, as compared to the direct irradiated case. Directly irradiated biofilms produced average electrical powers of 5.7 μW/m{sup 2} and plasmonically excited biofilms produced average electrical powers of 5.8 μW/m{sup 2}, with individual biofilms producing as much as 12 μW/m{sup 2}.

  2. Terahertz spectra revealing the collective excitation mode in charge-density-wave single crystal LuFe{sub 2}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiumei; Jin, Zuanming; Lin, Xian; Ma, Guohong [Department of Physics, Shanghai University (China); Cheng, Zhenxiang [Institute for Superconducting and Electronic Materials, University of Wollongong, NSW (Australia); Balakrishnan, Geetha [Department of Physics, University of Warwick, Coventry (United Kingdom)

    2017-09-15

    A low-energy collective excitation mode in charge-ordered multiferroic LuFe{sub 2}O{sub 4} is reported via terahertz time-domain spectroscopy. Upon cooling from 300 to 40 K, the central resonance frequency showed a pronounced hardening from 0.85 to 1.15 THz. In analogy to the well-known low-energy optical properties of LuFe{sub 2}O{sub 4}, this emerging resonance was attributed to the charge-density-wave (CDW) collective excitations. By using the Drude-Lorentz model fitting, the CDW collective mode becomes increasingly damped with the increasing temperature. Furthermore, the kinks of the CDW collective mode at the magnetic transition temperature are analyzed, which indicate the coupling of spin order with electric polarization. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Selfconsistent diabatic approach to dissipative collective nuclear motion

    International Nuclear Information System (INIS)

    Niita, K.; Wang, S.J.; Noerenberg, W.; Technische Hochschule Darmstadt

    1986-09-01

    Within a selfconsistent description for the one- and two-body density matrices collective variables are introduced via scaling diabatic states. Equations of collective motion coupled to a collision integral for the single-particle occupation probabilities are derived from the randomness of the two-body interaction matrix elements and from an additional time smoothing procedure. For a linear approximation to the time-dependence of the single-particle energies the collision term conserves energy all by itself, i.e. the time-smoothed time derivative of the correlation energy vanishes. (orig.)

  4. Excitation functions of deuteron-induced nuclear reactions on natural platinum up to 24 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Khandaker, Mayeen Uddin, E-mail: mu_khandaker@yahoo.com [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Haba, Hiromitsu; Murakami, Masashi [Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Otuka, Naohiko [Nuclear Data Section, Division of Physical and Chemical Sciences, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, A-1400 Vienna (Austria); Kassim, Hasan Abu [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2015-11-01

    Excitation functions of the {sup nat}Pt(d,x){sup 192,193,194,195,196m2,196,198m,198,199}Au, {sup 195m,197}Pt and {sup 190(g+m1+0.086m2),192(g+m1),194m}Ir nuclear reactions were measured from the respective threshold up to 24 MeV deuteron energy by using the stacked foil activation technique combined with HPGe gamma-ray spectrometry. Measured data were critically compared with the available literature data and theoretical data extracted from the TENDL-2013 library, and only partial agreement among them was found. Physical thick target yields for the investigated reaction products were also deduced and compared with the directly measured ones in the literature. The deduced yield curves indicate that a low energy cyclotron (<15 MeV) and a highly enriched {sup 198}Pt target could be used to obtain {sup 198,199}Au in no carrier added form. All cross-sections for {sup 190(g+m1+0.086m2),194m}Ir and those for {sup 193,194,196m2,196,199}Au, and {sup 195m,197}Pt in the lower energy region are reported for the first time.

  5. Investigations of dynamic interactions coupled by soil between neighbouring nuclear power plants of high mass in case of seismic excitation

    International Nuclear Information System (INIS)

    Matthees, W.; Magiera, G.

    1980-01-01

    A sensitivity study for the interaction effects for adjacent structures of nuclear power plants i.e. for main buildings and auxiliary buildings has been performed due to horizontal seismic excitation. An interaction measuring rule for response spectra has been defined as the ratio of amplitude of response calculated inclusive the auxiliary building to the amplitude calculated without the auxiliary building in respect to the proper eigen-frequencies. The calculations of the three-dimensional effects are approximated with the program FLUSH. The accuracy of the achievable response herewith calculated is proven in comparison with other suitable methods. The interaction measuring rule is determined by a parameter investigation including the mathematical model consisting of the soil, the main building, and the auxiliary building. The following assumptions are asserted: 1. the soil characteristics are temporarily constant. Ignorance of the accuracy of the realistic i.e. stress depending soil values is encountered by variation of the decisive characteristics within their applicable band-width. 2. The fineness of the mathematical-mechanical modelling for the structural systems i.e. the number of the degrees of freedom is limited to a minimum. Attention is hereby paid that the eigen-frequencies of the main building as well as the eigen-frequencies of the layered soil system in the range of 0 to 10 Hz are computed with sufficient accuracy. (orig./HP) [de

  6. Coulomb-nuclear interference with 6Li: Isospin character of the 21+ excitation in 70,72,74Ge

    International Nuclear Information System (INIS)

    Barbosa, M.D.L.; Borello-Lewin, T.; Horodynski-Matsushigue, L.B.; Duarte, J.L.M.; Rodrigues, C.L.; Rodrigues, M.R.D.; Ukita, G.M.

    2005-01-01

    Ratios of B(E2) to B(IS2), that is, of the reduced quadrupole transition probabilities related, respectively, to charge and mass were extracted through Coulomb-nuclear interference (CNI) for the excitation of the 2 1 + states in 70,72,74 Ge, with a relative accuracy of less than 4%. For this purpose, the CNI angular distributions associated with the inelastic scattering of 28-MeV incident 6 Li ions accelerated by the Sao Paulo Pelletron, and momentum analyzed by the Enge magnetic spectrograph were interpreted within the DWBA-DOMP approach (distorted wave approximation for the scattering process and deformed optical model for the structure representation) with global 6 Li optical parameters. The present CNI results demonstrate an abrupt change in the B(E2)/B(IS2) ratio for 74 Ge: although for 70,72 Ge, values of the order of 1.0 or slightly higher were obtained, this ratio is 0.66 (7) for 74 Ge. The heavier Ge isotope is thus one of the few nuclei that, so far, have been shown to present clear mixed symmetry components in their ground-state band

  7. Excitation functions of 3He- and α-particle induced nuclear reactions on natSb for production of medically relevant 123I and 124I radioisotopes

    International Nuclear Information System (INIS)

    Tarkanyi, F.; Takacs, S.; Kiraly, B.; Szelecsenyi, F.; Ando, L.; Bergman, J.; Heselius, S.-J.; Solin, O.; Hermanne, A.; Shubin, Yu.N.; Ignatyuk, A.V.

    2009-01-01

    Excitation functions were measured using the stacked foil irradiation technique from threshold energies to 28 MeV for 3 He- and to 21 MeV for α-particle induced nuclear reactions on natural antimony leading to the formation of 121,123,124 I radioisotopes. The measured excitation functions were compared with the contradicting results of the earlier investigations found in the literature and with the curves predicted by the ALICE-IPPE and EMPIRE-II codes. Integral yields were also calculated and compared with the experimental thick target yields reported in the literature.

  8. Collection and evaluation of nuclear data of Th-232

    International Nuclear Information System (INIS)

    Osawa, Takaaki

    1979-01-01

    Present status of the requirement to and measurement and evaluation of the nuclear data of Th-232 is presented. The accuracy and energy range of the observed data at present are not enough to the demand from reactor engineering. The data of total cross-section are given in the energy range from 1.5 to 15 MeV from the data by Foster and Fasoli. The data by Uttley for the energy less than 1.5 MeV were accepted. Recently, Whalen and Kobayashi presented new data. Optical potential parameters were deduced. Re-normalization of the capture cross-sections of Th-232 was made on the basis of the evaluated values by Matsunobu and by Kanda. The values are a little smaller than the values in ENDF/B-4. Fission cross-sections were given by Henkel up to 9 MeV, and by Rago and Pankratov for the energy range above 9 MeV. Recently, Behrens presented new data for wide energy range. The accuracy of the measured cross-sections of inelastic scattering is not enough for reactor design. The accurate values of the cross-sections of (n, 2n) reaction of Th-232 have been demanded. Resonance parameters have been measured for wide energy range. In the energy range of thermal neutrons, the capture cross-section is about 7.4 barn. The characteristics of velocity dependence of the capture cross-section in this range should be investigated. (Kato, T.)

  9. Collective behavior in nuclear interactions and shower development

    CERN Document Server

    Canoa, V.; Pajares, C.; Vazquez, Ricardo A.

    2005-01-01

    The mechanism of hadronic interactions at very high energies is still unclear. Available accelerator data constrain weakly the forward rapidity region which determines the development of atmospheric showers. This ignorance is one of the main sources of uncertainty in the determination of the energy and composition of the primary in hadron-induced atmospheric showers. In this paper we examine the effect on the shower development of two kinds of collective effects in high-energy hadronic interactions which modify the production of secondary particles. The first mechanism, modeled as string fusion, affects strongly the central rapidity region but only slightly the forward region and is shown to have very little effect on the shower development. The second mechanism implies a very strong stopping; it affects modestly the profile of shower maximum but broadens considerably the number distribution of muons at ground. For the latter mechanism, the development of air showers is faster mimicking a heavier projectile. ...

  10. Quantum entanglement analysis of an optically excited coupling of two nuclear spins via a mediator: Combining the quantum concurrence and negativity

    Science.gov (United States)

    Fu, Chenghua; Hu, Zhanning

    2018-03-01

    In this paper, we investigate the characteristics of the nuclear spin entanglement generated by an intermedium with an optically excited triplet. Significantly, the interaction between the two nuclear spins presents to be a direct XY coupling in each of the effective subspace Hamiltonians which are obtained by applying a transformation on the natural Hamiltonian. The quantum concurrence and negativity are discussed to quantitatively describe the quantum entanglement, and a comparison between them can reveal the nature of their relationship. An innovative general equation describing the relationship between the concurrence and negativity is explicitly obtained.

  11. Precision measurement of sub-nanosecond lifetimes of excited nuclear states using fast-timing coincidences with LaBr3(Ce) detectors

    International Nuclear Information System (INIS)

    Regan, P.H.

    2015-01-01

    Precision measurements of electromagnetic (EM) transition rates enable tests of models of internal nuclear structure. Measurements of transition rates can be used to infer the spin and parity differences between the initial and final discrete nuclear excited states via which the EM transition takes place. This short conference paper reports on developments of detection systems for the identification of discrete energy gamma-ray decays using arrays of halide-scintillation detectors acting in coincidence mode, which can be used to determine electromagnetic transition rates between excited nuclear states in the sub-nanosecond temporal regime. Ongoing development of a new multi-detector LaBr 3 (Ce) array for studies of exotic nuclei produced at the upcoming Facility for Anti-Proton and Ion Research (FAIR) as part of the NUSTAR–DESPEC project are presented, together with initial results from pre-NUSTAR implementations of this array for nuclear structure studies of neutron-rich fission fragment radionuclides at ILL-Grenoble, France and RIBF at RIKEN, Japan. - Highlights: • This paper reports on new detection systems for identification of gamma decays. • It focusses on using arrays of halide-scintillation detectors in coincidence mode. • These can determine lifetimes of nuclear states at the sub-ns level. • Plans for new LaBr3(Ce) arrays for studies of exotic nuclei are presented.

  12. Analysis of Air Activity Concentration Data Collected in the Kanto Plain, Japan, following the 2011 Fukushima Daiichi Nuclear Accident

    Science.gov (United States)

    2015-06-09

    Concentration Data Collected in the Kanto Plain, Japan, following the 2011 Fukushima Daiichi Nuclear Accident 5a. CONTRACT NUMBER 5b. GRANT NUMBER...collected at three locations following the release of radioactive materials from the Fukushima Daiichi Nuclear Power Station. The time series at...useful in other similar exposure situations. 15. SUBJECT TERMS Operation Tomodachi, Department of Defense, Japan, Fukushima , accidents, nuclear

  13. Collective spin excitations in the singlet-correlated band model: a comparison with resonant inelastic x-ray scattering

    International Nuclear Information System (INIS)

    Eremin, M V; Shigapov, I M; Thuy, Ho Thi Duyen

    2013-01-01

    We analyse the spin excitations near the optimal doping of superconducting layered cuprates taking into account both the local and the itinerant spin components self-consistently. The obtained expression allows us to reproduce well the basic features of the resonant inelastic x-ray scattering and neutron scattering data experiments using a reasonable set of tight-binding parameters corresponding to the angle-resolved photoemission spectroscopy data. We also find that the spin excitation branch along the (0,0) − (0,π) symmetry direction in the first Brillouin zone shows a splitting at T c . Possible experiments for verification of that prediction are briefly discussed. (paper)

  14. Analysis of the evolution of the collective dose in nuclear power plants in Spain

    International Nuclear Information System (INIS)

    Ponjuan Reyes, G.; Ruibia Rodiz, M. A. de la; Rosales Calvo, M.; Labarta Mancho, T.; Calavia Gimenez, I.

    2011-01-01

    This article presents an analysis of the evolution of occupational collective dose of the Spanish nuclear power planLs during the period 2000 - 2008 within the international context, by the Nuclear SafeLy Council (CSN) in order to have information contrasted to assessing the extent of applicaLion of the ALARA criLeria in the Spanish plants and identify areas of priority attention.

  15. Estimated collective effective dose to the population from nuclear medicine examinations in Slovenia

    International Nuclear Information System (INIS)

    Skrk, Damijan; Zontar, Dejan

    2013-01-01

    A national survey of patient exposure from nuclear medicine diagnostic procedures was performed by Slovenian Radiation Protection Administration in order to estimate their contribution to the collective effective dose to the population of Slovenia. A set of 36 examinations with the highest contributions to the collective effective dose was identified. Data about frequencies and average administered activities of radioisotopes used for those examinations were collected from all nuclear medicine departments in Slovenia. A collective effective dose to the population and an effective dose per capita were estimated from the collected data using dose conversion factors. The total collective effective dose to the population from nuclear medicine diagnostic procedures in 2011 was estimated to 102 manSv, giving an effective dose per capita of 0.05 mSv. The comparison of results of this study with studies performed in other countries indicates that the nuclear medicine providers in Slovenia are well aware of the importance of patient protection measures and of optimisation of procedures

  16. Collection of papers presented at conference on application of computers in nuclear power plants

    International Nuclear Information System (INIS)

    1990-01-01

    The collection contains full texts of 22 contributions, 18 of which fall within the INIS subject scope. The topics treated included the application of computers particularly in the management of a nuclear power plant as a corporation, in the start-up and control of the reactor units and in the control of the production process in a nuclear power plant. Attention was also paid to the diagnostics of the equipment and to automated control systems for the management of basic equipment of the nuclear power plant. (Z.M.)

  17. Occupational dose reduction developments and data collected at nuclear power plants

    International Nuclear Information System (INIS)

    Dionne, B.J.; Baum, J.W.

    1984-01-01

    Occupational dose reduction developments and data collected at nuclear power plants have been described. Written descriptions of repetitive high dose jobs, their collective dose equivalent ranges and list of dose reduction techniques will aid in reducing collective dose equivalents from these dose-reduction targets. Knowing which components contribute to high maintenance or repair dose will aid in reducing routine maintenance collective dose equivalents. The radwaste dose reduction improvements will aid in reducing radwaste operations collective dose equivalent and reduce the number of radwaste workers who exceed their administrative dose limits. The identification and rating of managers' and workers' ALARA incentives will provide the basis for recommendations to improve dose reduction incentives. Lastly, the identification and rating of the key components of an ALARA program will aid in the development and coordination of the nuclear station ALARA programs

  18. Estimates of collective doses from a hypothetical accident of a nuclear submarine

    International Nuclear Information System (INIS)

    Kobayashi, Takuya; Togawa, Orihiko; Odano, Naoteru; Ishida, Toshihisa

    2001-01-01

    The collective dose to the Japanese population has been estimated from a hypothetical accident of a nuclear submarine if it sinks in an offshore region around Japan. A computer code system DSOCEAN has been used for assessing the collective dose due to radionuclides released to the ocean from a sunken nuclear submarine. The estimated collective effective dose commitment from all of the radionuclides released after the break of the fuel pellets is estimated to be 2.5 x l0 4 man·Sv. The contribution of 241 Am to the total collective effective dose commitment is the highest, followed by 137 Cs, 238 Pu, 240 Pu, 239 Pu and 241 Pu. The maximum of the estimated collective effective dose by the annual intake of marine products after radionuclide releases for one year is approximately 0.3% of the annual average dose by the natural radiation that is reported by UNSCEAR. (author)

  19. Collective spin by linearization of the Schrodinger equation for nuclear collective motion

    International Nuclear Information System (INIS)

    Greiner, M.; Scheid, W.; Herrmann, R.

    1988-01-01

    The free Schrodinger equation for multipole degrees of freedom is linearized so that energy and momentum operators appear only in first order. As an example, the authors demonstrate the linearization procedure for quadrupole degrees of freedom. The wave function solving this equation carries a spin. The authors derive the operator of the collective spin and its eigen values depending on multipolarity

  20. Diabaticity of nuclear motion: problems and perspectives

    International Nuclear Information System (INIS)

    Nazarewicz, W.

    1993-01-01

    The assumption of adiabatic motion lies in foundations of many models of nuclear collective motion. To what extend can nuclear modes be treated adiabatically? Due to the richness and complexity of the nuclear many-body problem there is no unique answer to this question. The challenges of nuclear collective dynamics invite exciting interactions between several areas of physics such as nuclear structure, field theory, non-linear dynamics, transport theory, and quantum chaos. (orig.)

  1. Extreme breathing excitations of atomic nuclei

    International Nuclear Information System (INIS)

    Antonov, A.N.; Nikolaev, V.A.; Petkov, I.Zh.

    1984-01-01

    In the present paper collective breathing nuclear states, that appear in the framework of the coherent density fluctuation model (CFM) are taken into consideration. Their excitation energies are large and comparable with the binding nuclear energies. The basic CFM equation obtain in the generator-coordinate method. The possible mechanisms for the excitations for the excitations of the breathing states are deeply inelastic interactions of particles (e - , p, etc.) with nuclei, the π - -absorbtion from nuclei. It should be noted, that the energy of the Roper-resonance is comparable with the breathing nuclear excitation energies. Therefore the decay of this resonance, in principle, can lead to the breathing nuclear vibrations. The results of this work, as well as the results of some papers, obtained by means of a similar method but related to different quantum-mechanical systems, give an evidence, that the structure in detail and the character of the forces between the particles are not decisive for the considered type of excitations

  2. Contribution to the determination of nuclear friction by studying the de-excitation of nuclei in the transient regime

    International Nuclear Information System (INIS)

    Hassani, S.

    1985-01-01

    An old idea of Kramers is to consider nuclear fission as a diffusion process in phase space corresponding to the collective variable of fission. The fission width is taken as an escape rate of the system over the barrier potential. The evolution of the distribution of this collective variable and its conjugate is governed by a Fokker-Planck equation. In a quasistationary treatment Kramers obtained a fission rate which differs from the result given by the transition state method by a friction dependent factor. The non quasistationary solution of the Fokker-Planck equation allows to obtain an escape rate that presents a transient regime: from zero it grows and reaches asymptotically the Kramers' value. This time-dependent fission width is included in a formalism that describes the deexcitation of the compound nucleus in order to calculate the neutron multiplicities in competition with fission. A sensitive friction-dependence of the multiplicities is obtained. Using this formalism and comparing the results with data of a recent experiment gives a good agreement; resolving the disagreement between data and the usual statistical model at high energy. A range of values of the friction coefficient is deduced [fr

  3. Precision measurement of sub-nanosecond lifetimes of excited nuclear states using fast-timing coincidences with LaBr3(Ce) detectors

    Science.gov (United States)

    Regan, P. H.

    2015-11-01

    Precision measurements of electromagnetic (EM) transition rates enable tests of models of internal nuclear structure. Measurements of transition rates can be used to infer the spin and parity differences between the initial and final discrete nuclear excited states via which the EM transition takes place. This short conference paper reports on developments of detection systems for the identification of discrete energy gamma-ray decays using arrays of halide-scintillation detectors acting in coincidence mode, which can be used to determine electromagnetic transition rates between excited nuclear states in the sub-nanosecond temporal regime. Ongoing development of a new multi-detector LaBr3(Ce) array for studies of exotic nuclei produced at the upcoming Facility for Anti-Proton and Ion Research (FAIR) as part of the NUSTAR-DESPEC project are presented, together with initial results from pre-NUSTAR implementations of this array for nuclear structure studies of neutron-rich fission fragment radionuclides at ILL-Grenoble, France and RIBF at RIKEN, Japan.

  4. Collective dose to the European Community from nuclear industry effluents discharge in 1978

    CERN Document Server

    Camplin, W C

    1983-01-01

    The results are presented of a study to evaluate the collective dose commitment to the population of the European Community from effluents released by the nuclear industry within the EC in 1978. Airborne and liquid effluent discharge data have been taken from published sources, and computer modelling techniques have been used to predict the transfer of radioactivity through the environment to man. The collective dose commitments due to discharges from each nuclear installation have been evaluated and the comparative significance of individual radionuclides and their pathways to man have been considered. Airborne releases resulted in an estimated collective effective dose equivalent commitment of 95 man Sv, the major part of which is due to carbon-14 from both power stations and reprocessing plants. The collective effective dose equivalent commitment from liquid effluents is estimated to be 408 man Sv, mostly due to caesium-137 and other radionuclides from the Sellafield (formerly Windscale) reprocessing plant...

  5. Nuclear Engineering Committee KTA. A collection of definitions as of January 16, 1987

    International Nuclear Information System (INIS)

    Riedel, U.

    1987-01-01

    The collection of definitions mainly comprises terms which are laid down in the recommendations of the Nuclear Engineering Committee (KTA) or in overriding regulations and specifications. The collection aims at a KTA-standardized use of terms and at the avoidance of groundless divergences. The compiled definitions are followed by a list of the sources considered, namely laws, ordinances, administrative recommendations, KTA regulations as well as other recommendations and standards. (orig./HSCH) [de

  6. Study of the effect of shell stabilization of the collective isovector valence-shell excitations along the N=80 isotonic chain

    CERN Multimedia

    It is proposed to investigate the microscopic mechanism which leads to a concentration or a fragmentation of the quadrupole-collective isovector valence-shell excitations, the so-called mixed-symmetry states (MSSs), an effect called shell stabilization of MSSs. This aim will be achieved by identification of MSSs of the unstable nuclei $^{140}$Nd and $^{142}$Sm. The first steps of this program have been undertaken in two subsequent REX-ISOLDE experiments (IS496) in which we have measured the B(E2; 2$^{+}_{1}$$\\rightarrow$ 0$^{+}_{1}$) transition strengths in the radioactive nuclei $^{140}$Nd and $^{142}$Sm. By using these data and the higher beam energy of HIE-ISOLDE we propose now to identify the MSSs of these nuclei by measuring their relative populations with respect to the population of the first 2$^{+}$ states in Coulomb excitation (CE) reactions.

  7. A guide to archival collections relating to radioactive fallout from nuclear weapon testing

    International Nuclear Information System (INIS)

    Martin, B.W.

    1992-09-01

    This ninth edition of A Guide to Archival Collections Relating to Radioactive Fallout from Nuclear Weapon Testing constitutes History Associates Incorporated's (HAI) final report of its document collection, processing, and declassification efforts for the Nevada Field Office of the Department of Energy. The most significant feature of this edition is the updated HAI collection effort information. We confirmed the accuracy of this information using our screening, processing, and transmittal records. Unlike previous editions, funding limitations prevented us from systematically revising the collection descriptions and point-of-contact information for this final edition. This guide has been prepared by professional historians who have a working knowledge of many of the record collections included in the following pages. In describing materials, they have tried to include enough information so that persons unfamiliar with the complexities of large record systems will be able to determine that nature of the information in, and the quality of, each record collection

  8. Fast ion collisions with C 60 in vapour phase and collective excitation: Comparison with other gaseous targets

    Science.gov (United States)

    Tribedi, Lokesh C.; Kelkar, Aditya H.; Kasthurirangan, Siddharth

    2010-10-01

    The single and double ionization of a free C 60 molecule in collisions with fast heavy (F and Si) ions is investigated using a recoil ion time-of-flight mass spectrometer. The projectile charge state ( qp) dependence has also been investigated. A linear qp-dependence has been explained in terms of a plasmon excitation model. In addition, continuum electron spectroscopy has been used to detect the electron emission from fullerenes. The measured electron angular distribution for the fullerene target is compared with that for a gaseous target at a fixed electron energy. The ratio of forward-to-backward cross section for C 60 is quite different from that for Ne.

  9. Measurements of octupole collectivity in $^{220,222}$Rn and $^{222,224}$Ra using Coulomb excitation

    CERN Multimedia

    Kruecken, R; Larsen, A; Hurst, A M; Voulot, D; Grahn, T; Clement, E; Wadsworth, R; Gernhaeuser, R A; Siem, S; Huyse, M L; Iwanicki, J S

    2008-01-01

    We propose to exploit the unique capability of ISOLDE to provide post-accelerated $^{220,222}$Rn and $^{222,224}$Ra ion beams from the REX facility to enable the Coulomb excitation of the first 3$^{-}$ states in these nuclei. By measuring the $\\gamma$-ray yields of the E1 decays from the 3$^{-}$ state using the MINIBALL array we can obtain the transition matrix elements. This will give quantitative information about octupole correlations in these nuclei. We require 22 shifts to fulfil the aims of the experiment.

  10. Excited state nuclear forces from the Tamm-Dancoff approximation to time-dependent density functional theory within the plane wave basis set framework

    Science.gov (United States)

    Hutter, Jürg

    2003-03-01

    An efficient formulation of time-dependent linear response density functional theory for the use within the plane wave basis set framework is presented. The method avoids the transformation of the Kohn-Sham matrix into the canonical basis and references virtual orbitals only through a projection operator. Using a Lagrangian formulation nuclear derivatives of excited state energies within the Tamm-Dancoff approximation are derived. The algorithms were implemented into a pseudo potential/plane wave code and applied to the calculation of adiabatic excitation energies, optimized geometries and vibrational frequencies of three low lying states of formaldehyde. An overall good agreement with other time-dependent density functional calculations, multireference configuration interaction calculations and experimental data was found.

  11. Excitation of giant resonances through inelastic scattering

    International Nuclear Information System (INIS)

    Kailas, S.

    1981-01-01

    In the last few years, exciting developments have taken place in the study of giant resonances (GR). In addition to the already well known gjant dipole resonance (GDR), the presence of at least two more new GRs viz. giant quadrupole resonance (GQR) and giant monopole resonance (GMR) has been experimentally established. The systematics covering these GRs is found to be consistent with the theoretical expectation. Though the existence of higher multipoles has been predjcted by theory, so far only some of these have been found to be excited experimentally. Various probe particles - electrons, protons (polarized and unpolarized), light and heavy ions and pions - at different bombarding energies have been used to excite the GR region, primarily through the inelastic scattering process. Detailed experiments, looking at the decay modes of GR region, have also been performed. These studies have contributed significantly to a better understanding of the phenomenon of nuclear collective excitation. In this report, the current status of 'GR' research is reviewed. (author)

  12. Impact parameter selected nuclear temperatures of hot nuclei from excited state populations for 40Ar+197Au reactions at E/A=25MeV

    International Nuclear Information System (INIS)

    Li Zuyu; He Zhiyong; Duan Limin; Jin Genming; Wu Heyu; Zhang Baoguo; Wen Wanxin; Qi Yujin; Luo Qingzheng; Dai Guangxi; Wang Hongwei

    1997-01-01

    Nuclear temperatures extracted from excited state populations were measured as a function of linear momentum transfer (LMT) for 40 Ar+ 197 Au reactions at 25MeV/nucleon. The emission temperatures increased slightly with increasing linear momentum transfer or decreasing impact parameter. Taking into account the corrections of detection efficiency and sequential feeding from higher-lying states, a temperature of T∼4MeV was deduced for central collisions. For peripheral collisions the extracted temperatures increased with the energy of the particles. (orig.)

  13. Considerations on safety against seismic excitations in the project of reactor auxiliary building and control building in nuclear power plants

    International Nuclear Information System (INIS)

    Santos, S.H.C.; Castro Monteiro, I. de

    1986-01-01

    The seismic requests to be considered in the project of main buildings of a nuclear power plant are discussed. The models for global seismic analysis of nuclear power plant structures, as well as models for global strength distribution are presented. The models for analysing reactor auxiliary building and control building, which together with the reactor building and turbine building form the main energy generation complex in a nuclear power plant, are described. (M.C.K.) [pt

  14. Study of the effect of shell stabilization of the collective isovector valence-shell excitations along the N=80 isotonic chain

    CERN Multimedia

    Blazhev, A A; Kruecken, R; Coquard, L; Bloch, T P; Wadsworth, R; Danchev, M T; Jenkins, D G; Kroell, T; Leske, J

    It is proposed to initiate an experimental program to study the quadrupole-collective isovector valence-shell excitations the so-called mixed-symmetry states (MSSs) of unstable nuclei from the N = 80 isotonic chain. The main aim of this program is to investigate the microscopic mechanism which leads to a concentration or a fragmentation of the MSSs, an effect dubbed $\\textit{shell stabilization}$ of MSSs. This will be achieved by identification of MSSs of the unstable nuclei $^{140}$Nd and $^{142}$Sm. The MSSs of these nuclei will be identified experimentally by measuring their relative populations with respect to the population of the first 2$^{+}$ states in inverse kinematics Coulomb excitation (CE) reactions on light targets. As a first step of this program we apply for a beam time for the radioactive $^{140}$Nd and $^{142}$Sm beams at beam energy of 2.85 MeV/u. These beams will be used to determine the absolute B(E2;2$_{1}^{+} \\rightarrow$ 0$_{1}^{+}$) values for $^{140}$Nd and $^{142}$Sm in Coulomb excit...

  15. Excitation functions of natZn(p,x) nuclear reactions with proton beam energy below 18 MeV

    OpenAIRE

    Asad, A. H.; Chan, S.; Morandeau, L.; Cryer, D.; Smith, S. V.; Price, R. I.

    2015-01-01

    Introduction We measured the excitation functions of natZn (p,x) reactions up to 17.6 MeV using the stacked-foils activation technique. High-purity natural zinc (and copper) foils were irradiated with proton beams from an 18MeV medical cyclotron, the predominant purpose of which is to provide a routine regional service for clinical PET radiopharmaceuticals. Thick-target integral yields were also deduced from the measured excitation functions of the produced radioisotopes. These results we...

  16. X-ray-excited optical luminescence of protein crystals: a new tool for studying radiation damage during diffraction data collection.

    Science.gov (United States)

    Owen, Robin L; Yorke, Briony A; Pearson, Arwen R

    2012-05-01

    During X-ray irradiation protein crystals radiate energy in the form of small amounts of visible light. This is known as X-ray-excited optical luminescence (XEOL). The XEOL of several proteins and their constituent amino acids has been characterized using the microspectrophotometers at the Swiss Light Source and Diamond Light Source. XEOL arises primarily from aromatic amino acids, but the effects of local environment and quenching within a crystal mean that the XEOL spectrum of a crystal is not the simple sum of the spectra of its constituent parts. Upon repeated exposure to X-rays XEOL spectra decay non-uniformly, suggesting that XEOL is sensitive to site-specific radiation damage. However, rates of XEOL decay were found not to correlate to decays in diffracting power, making XEOL of limited use as a metric for radiation damage to protein crystals. © 2012 International Union of Crystallography

  17. Fast ion collisions with C{sub 60} in vapour phase and collective excitation: Comparison with other gaseous targets

    Energy Technology Data Exchange (ETDEWEB)

    Tribedi, Lokesh C., E-mail: lokesh@tifr.res.i [Tata Institute of Fundamental Research, Mumbai (India); Kelkar, Aditya H. [Tata Institute of Fundamental Research, Mumbai (India); Kasthurirangan, Siddharth [Tata Institute of Fundamental Research, Mumbai (India); Institute of Chemical Technology, Mumbai (India)

    2010-10-01

    The single and double ionization of a free C{sub 60} molecule in collisions with fast heavy (F and Si) ions is investigated using a recoil ion time-of-flight mass spectrometer. The projectile charge state (q{sub p}) dependence has also been investigated. A linear q{sub p}-dependence has been explained in terms of a plasmon excitation model. In addition, continuum electron spectroscopy has been used to detect the electron emission from fullerenes. The measured electron angular distribution for the fullerene target is compared with that for a gaseous target at a fixed electron energy. The ratio of forward-to-backward cross section for C{sub 60} is quite different from that for Ne.

  18. Giant resonances on excited states

    International Nuclear Information System (INIS)

    Besold, W.; Reinhard, P.G.; Toepffer, C.

    1984-01-01

    We derive modified RPA equations for small vibrations about excited states. The temperature dependence of collective excitations is examined. The formalism is applied to the ground state and the first excited state of 90 Zr in order to confirm a hypothesis which states that not only the ground state but every excited state of a nucleus has a giant resonance built upon it. (orig.)

  19. Nuclear energy: technology, safety, ecology, economy, management. The I All-Russian scientific-practical conference of young nuclear scientists of Siberia. Collection of scientific papers

    International Nuclear Information System (INIS)

    2010-01-01

    Collection of research papers I All-Russian scientific-practical conference of young nuclear scientists in Siberia, held 19-25 September 2010 in Tomsk, is presented. The edition contains material on a wide range of research scientists-economists, professors, graduate students and young scientists, and school children of Tomsk, Seversk, and several other Russian cities on the technology, security, ecology, economics, management in the nuclear power industry. Discussion of the presented research was conducted on sections: 1. Technological support for the nuclear fuel cycle, 2. Nuclear non-proliferation and environmental safety of the nuclear fuel cycle, 3. Energy: Present and Future 4. It all starts with an idea [ru

  20. Data collection and record keeping for the management of nuclear power plant ageing: A safety practice

    International Nuclear Information System (INIS)

    1991-01-01

    This Safety Practice is the first in a series of reports under the programme on the management of nuclear power plant ageing. The purpose of the programme is to facilitate the exchange of information and to promote co-operation among Member States towards understanding and managing the ageing degradation of components, with the aim of maintaining safe and reliable plant operation. The availability and evaluation of appropriate data on nuclear power plant components are essential to safety and constitute a key factor in plant life extension considerations. The present publication provides guidance on data requirements and an effective and practical system for data collection and record keeping in relation to the evaluation and management of ageing and service life. This guidance is based on current practices. It is envisaged that the application of the guidance will contribute to the safe and reliable operation of nuclear power plants and will facilitate international information exchange on ageing related component failures, malfunctions and degradation, since data collected using the same ground rules would be easier to exchange and compare. The guidance is intended primarily for the management, maintenance and technical staff of nuclear power plants, on whom the ultimate success of the recommended system and its associated benefits depend. Intended secondary audiences include utility management and central technical support organizations, regulatory bodies, standards organizations, design companies, and research and development institutes. 8 refs, 1 fig., 1 tab

  1. Nuclear power plant containment metallic pressure boundary materials and plans for collecting and presenting their properties

    International Nuclear Information System (INIS)

    Oland, C.B.

    1995-04-01

    A program is being conducted at the Oak Ridge National Laboratory (ORNL to assist the Nuclear Regulatory Commission (NRC)) in their assessment of the effects of degradation (primarily corrosion) on the structural capacity and leaktight integrity of metal containments and steel liners of reinforced concrete structures in nuclear power plants. One of the program objectives is to characterize and quantify manifestations of corrosion on the properties of steels used to construct containment pressure boundary components. This report describes a plan for use in collecting and presenting data and information on ferrous alloys permitted for use in construction of pressure retaining components in concrete and metal containments. Discussions about various degradation mechanisms that could potentially affect the mechanical properties of these materials are also included. Conclusions and recommendations presented in this report will be used to guide the collection of data and information that will be used to prepare a material properties data base for containment steels

  2. Collection and evalution of abnormal occurrences in German nuclear power plants

    International Nuclear Information System (INIS)

    Hoffmeister

    1976-01-01

    The systematic consideration of operating experiences which must be recorded, collected and evaluated, is important for the realisation of the aim of greater safety in nuclear power stations. Since commissioning of the first nuclear power stations in West Germany all significant events were communicated to the 'Laender' authorities responsible for controlling compliance with the licensing requirements. The evaluation of these events assured that the necessary consequences were carried out to prevent any recurrence. A systematic consideration of the operating experiences, however, was missing; therefore our institute was made responsible by the Federal Ministry of the Interior with the agreement of the 'Laender' authorities to record, collect and evaluate in accordance with reporting criteria and a classification system related to safety relevance. (orig./RW) [de

  3. Collective effective dose in Europe from X-ray and nuclear medicine procedures.

    Science.gov (United States)

    Bly, R; Jahnen, A; Järvinen, H; Olerud, H; Vassileva, J; Vogiatzi, S

    2015-07-01

    Population doses from radiodiagnostic (X-ray and nuclear medicine) procedures in Europe were estimated based on data collected from 36 European countries. For X-ray procedures in EU and EFTA countries (except Liechtenstein) the collective effective dose is 547,500 man Sv, resulting in a mean effective dose of 1.06 mSv per caput. For all European countries included in the survey the collective effective dose is 605,000 man Sv, resulting in a mean effective dose of 1.05 mSv per caput. For nuclear medicine procedures in EU countries and EFTA (except Liechtenstein) countries the collective effective dose is 30,700 man Sv, resulting in a mean effective dose of 0.06 mSv per caput. For all European countries included in the survey the collective effective dose is 31,100 man Sv, resulting in a mean effective dose of 0.05 mSv per caput. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. Analysis of the evolution of the collective dose in nuclear power plants in Spain; Analisis de la evolucion de la dosis colectiva en las centrales nucleares de Espana

    Energy Technology Data Exchange (ETDEWEB)

    Ponjuan Reyes, G.; Ruibia Rodiz, M. A. de la; Rosales Calvo, M.; Labarta Mancho, T.; Calavia Gimenez, I.

    2011-07-01

    This article presents an analysis of the evolution of occupational collective dose of the Spanish nuclear power plants during the period 2000 - 2008 within the international context, by the Nuclear Safety Council (CSN) in order to have information contrasted to assessing the extent of application of the ALARA criteria in the Spanish plants and identify areas of priority attention.

  5. Histamine Excites Rat Superior Vestibular Nuclear Neurons via Postsynaptic H1 and H2 Receptors in vitro

    Directory of Open Access Journals (Sweden)

    Qian-Xing Zhuang

    2012-09-01

    Full Text Available The superior vestibular nucleus (SVN, which holds a key position in vestibulo-ocular reflexes and nystagmus, receives direct hypothalamic histaminergic innervations. By using rat brainstem slice preparations and extracellular unitary recordings, we investigated the effect of histamine on SVN neurons and the underlying receptor mechanisms. Bath application of histamine evoked an excitatory response of the SVN neurons, which was not blocked by the low-Ca2+/high-Mg2+ medium, indicating a direct postsynaptic effect of the amine. Selective histamine H1 receptor agonist 2-pyridylethylamine and H2 receptor agonist dimaprit, rather than VUF8430, a selective H4 receptor agonist, mimicked the excitation of histamine on SVN neurons. In addition, selective H1 receptor antagonist mepyramine and H2 receptor antagonist ranitidine, but not JNJ7777120, a selective H4 receptor antagonist, partially blocked the excitatory response of SVN neurons to histamine. Moreover, mepyramine together with ranitidine nearly totally blocked the histamine-induced excitation. Immunostainings further showed that histamine H1 and H2 instead of H4 receptors existed in the SVN. These results demonstrate that histamine excites the SVN neurons via postsynaptic histamine H1 and H2 receptors, and suggest that the central histaminergic innervation from the hypothalamus may actively bias the SVN neuronal activity and subsequently modulate the SVN-mediated vestibular functions and gaze control.

  6. Investigations of collective and single-particle aspects of excitation in 1fsub(7/2) shell nuclei

    International Nuclear Information System (INIS)

    Styczen, J.

    1976-01-01

    Experimental data are presented which were obtained in spectroscopic studies on 1fsub(7/2) shell nuclei in the following reactions: 30 Si( 16 0,pn) 44 Sc, 44 Ca(p,n) 44 Sc, 42 Ca(α,p) 45 Sc, 42 Ca(α,n) 45 Sc, 45 Sc(α,pn) 47 Ti, 46 Ti(α,p) 49 V, 47 Ti(α,pn) 49 V, and 49 Ti(p,n) 49 V. Experimental reduced transition probabilities B(M1) and B(E2) have been systematically compared for inband transitions of Ksup(π)=3/2 + bands in sup(43,45,47)Sc, 45 Ti and sup(47,49)V nuclei. In the framework of the pure rotational model, intrinsic quadrupole moments |Qsub(o)| and |gsub(K)-gsub(R)| ratios have been derived. Band mixing calculations in a strong coupling model treating more correctly the j 2 term in the hamiltonian and hole excitations, have been indertaken on properties of negativeparity states in the cross-conjugate nuclei 47 Ti- 49 V and V 47 - 49 Dr. There is an overall good agreement between the experimental data and the theoretical predictions. The strong coupling model has been also used to study possible regions of stable deformation for the positive parity states of the odd nuclei in the 1fsub(7/2) shell. Band mixing calculations performed for these states have shown that the experimental data are well reproduced in the calculations with a deformation parameter corresponding to a minimum of the static potential energy. (author)

  7. Analytical data on contaminated water, rubble and other collected at the Fukushima Daiichi Nuclear Power Station

    International Nuclear Information System (INIS)

    Asami, Makoto; Takahatake, Youko; Koma, Yoshikazu; Myodo, Masato; Tobita, Takeshi; Kobayashi, Kiwami; Usui, Yuka; Watahiki, Hiromi; Shibata, Atsuhiro; Nomura, Kazunori; Hayakawa, Misa

    2017-03-01

    At Fukushima Daiichi Nuclear Power Station (hereinafter referred to as '1F') owned by Tokyo Electric Power Company Holdings, Inc. (formerly called Tokyo Electric Power Co., Inc. and hereinafter referred to as 'TEPCO'), contaminated water (accumulated, treated), the secondary waste produced by treatment of the contaminated water, and rubble and soil were collected and analyzed. So, the collected analysis data is important to develop post-accident waste management strategies for 1F, and will be useful for other projects related to decommissioning work. Thus, all the data already opened to public was gathered and summarized in this report. The analysis data collected herein was already published by TEPCO, Japan Atomic Energy Agency (JAEA) and International Research Institute for Nuclear Decommissioning (IRID) until the end of March, 2016. There are 544 reported samples for contaminated water, 6 for the secondary waste from contaminated water treatment system, 45 for rubble, and 331 for soil. Sample analysis information and the radionuclide inventory have been tabulated. Concentrations of major radionuclides are also shown in figures as a function of time. In addition, text translated into English and the collected data are available in electronic file format. A DVD-ROM is attached as an appendix. (J.P.N.)

  8. Vibrational motions in rotating nuclei studied by Coulomb excitations

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Yoshifumi R. [Kyushu Univ., Fukuoka (Japan). Dept. of Physics

    1998-03-01

    As is well-known Coulomb excitation is an excellent tool to study the nuclear collective motions. Especially the vibrational excitations in rotating nuclei, which are rather difficult to access by usual heavy-ion fusion reactions, can be investigated in detail. Combined with the famous 8{pi}-Spectrometer, which was one of the best {gamma}-ray detector and had discovered some of superdeformed bands, such Coulomb excitation experiments had been carried out at Chalk River laboratory just before it`s shutdown of physics division. In this meeting some of the experimental data are presented and compared with the results of theoretical investigations. (author)

  9. Collective dose estimation in Portuguese population due to medical exams of diagnostic radiology and nuclear medicine

    International Nuclear Information System (INIS)

    Teles, Pedro; Vaz, Pedro; Paulo, Graciano; Santos, Joana; Pascoal, Ana; Lanca, Isabel; Matela, Nuno; Sousa, Patrick; Carvoeiras, Pedro; Parafita, Rui; Simaozinho, Paula

    2013-01-01

    In order to assess the exposure of the Portuguese population to ionizing radiation due to medical examinations of diagnostic radiology and nuclear medicine, a working group, consisting of 40 institutions, public and private, was created to evaluation the coletive dose in the Portuguese population in 2010. This work was conducted in collaboration with the Dose Datamed European consortium, which aims to assess the exposure of the European population to ionizing radiation due to 20 diagnostic radiology examinations most frequent in Europe (the 'TOP 20') and nuclear medicine examinations. We obtained an average value of collective dose of ≈ 1 mSv/caput, which puts Portugal in the category of countries medium to high exposure to Europe. We hope that this work can be a starting point to bridge the persistent lack of studies in the areas referred to in Portugal, and to enable the characterization periodic exposure of the Portuguese population to ionizing radiation in the context of medical applications

  10. Excited states v.6

    CERN Document Server

    Lim, Edward C

    1982-01-01

    Excited States, Volume 6 is a collection of papers that discusses the excited states of molecules. The first paper discusses the linear polyene electronic structure and potential surfaces, considering both the theoretical and experimental approaches in such electronic states. This paper also reviews the theory of electronic structure and cites some experimental techniques on polyene excitations, polyene spectroscopic phenomenology, and those involving higher states of polyenes and their triplet states. Examples of these experimental studies of excited states involve the high-resolution one-pho

  11. Excited states 2

    CERN Document Server

    Lim, Edward C

    2013-01-01

    Excited States, Volume 2 is a collection of papers that deals with molecules in the excited states. The book describes the geometries of molecules in the excited electronic states. One paper describes the geometries of a diatomic molecule and of polyatomic molecules; it also discusses the determination of the many excited state geometries of molecules with two, three, or four atoms by techniques similar to diatomic spectroscopy. Another paper introduces an ordered theory related to excitons in pure and mixed molecular crystals. This paper also presents some experimental data such as those invo

  12. Model-based predictions for nuclear excitation functions of neutron-induced reactions on 64,66−68Zn targets

    Directory of Open Access Journals (Sweden)

    M. Yiğit

    2017-08-01

    Full Text Available In this paper, nuclear data for cross sections of the 64Zn(n,2n63Zn, 64Zn(n,3n62Zn, 64Zn(n,p64Cu, 66Zn(n,2n65Zn, 66Zn(n,p66Cu, 67Zn(n,p67Cu, 68Zn(n,p68Cu, and 68Zn(n,α65Ni reactions were studied for neutron energies up to 40 MeV. In the nuclear model calculations, TALYS 1.6, ALICE/ASH, and EMPIRE 3.2 codes were used. Furthermore, the nuclear data for the (n,2n and (n,p reaction channels were also calculated using various cross-section systematics at energies around 14–15 MeV. The code calculations were analyzed and obtained using the different level densities in the exciton model and the geometry-dependent hybrid model. The results obtained from the excitation function calculations are discussed and compared with literature experimental data, ENDF/B-VII.1, and the TENDL-2015 evaluated data.

  13. Model-based predictions for nuclear excitation functions of neutron-induced reactions on {sup 64,} {sup 66-68}Zn targets

    Energy Technology Data Exchange (ETDEWEB)

    Yigit, M. [Faculty of Science and Arts, Dept. of Physics, Aksaray University, Aksaray (Turkmenistan); Kara, A. [Faculty of Engineering, Department of Energy Systems Engineering, Giresun University, Giresun (Turkmenistan)

    2017-08-15

    In this paper, nuclear data for cross sections of the {sup 64}Zn(n,2n){sup 63}Zn,{sup 64}Zn(n,3n){sup 62}Zn, {sup 64}Zn(n,p){sup 64}Cu, {sup 66}Zn(n,2n){sup 65}Zn, {sup 66}Zn(n,p){sup 66}Cu, {sup 67}Zn(n,p){sup 67}Cu, {sup 68}Zn(n,p){sup 68}Cu, and {sup 68}Zn(n,α){sup 65}Ni reactions were studied for neutron energies up to 40 MeV. In the nuclear model calculations, TALYS 1.6, ALICE/ASH, and EMPIRE 3.2 codes were used. Furthermore, the nuclear data for the (n,2n) and (n,p) reaction channels were also calculated using various cross-section systematics at energies around 14–15 MeV. The code calculations were analyzed and obtained using the different level densities in the exciton model and the geometry-dependent hybrid model. The results obtained from the excitation function calculations are discussed and compared with literature experimental data, ENDF/B-VII.1, and the TENDL-2015 evaluated data.

  14. Selected topics in nuclear structure

    International Nuclear Information System (INIS)

    Solov'ev, V.G.; Gromov, K.Ya.; Malov, L.A.; Shilov, V.M.

    1994-01-01

    The Fourth International Conference on selected topics in nuclear structure was held at Dubna in July 1994 on recent experimental and theoretical investigations in nuclear structure. Topics discussed were the following: nuclear structure at low-energy excitations (collective quasiparticle phenomena, proton-neutron interactions, microscopic and phenomenological theories of nuclear structure; nuclear structure studies with charged particles. heavy ions, neutrons and photons; nuclei at high angular momenta and superdeformation, structure and decay properties of giant resonances, charge-exchange resonances and β-decay; semiclassical approach of large amplitude collective motion and structure of hot nuclei

  15. STRENGTH DISTRIBUTIONS IN NEODYMIUM ISOTOPES - A TEST OF COLLECTIVE NUCLEAR-MODELS

    NARCIS (Netherlands)

    PIGNANELLI, M; BLASI, N; BORDEWIJK, JA; DELEO, R; HARAKEH, MN; HOFSTEE, MA; MICHELETTI, S; PERRINO, R; PONOMAREV, VY; SOLOVIEV, VG; SUSHKOV, AV; VANDERWERF, SY

    1993-01-01

    Excite states n even N isotopes, up to excitation energies of 3-4 MeV, were investigate in proton- and deuteron-scattering experiments performed with high-energy resolution. More than 300 transitions were studied. For several new excited states spin and parity assignments have been suggested.

  16. Phase space description of collective nuclear vibrations with the Vlasov equation plus quantum corrections

    International Nuclear Information System (INIS)

    Kohl, H.; Stringari, S.; Schuck, P.

    1986-06-01

    We use the Vlasov equation plus the Planck's constant - corrections to describe collective nuclear vibrations in the small amplitude limit. Separable forces of the multipole - multipole type are employed to study the quadrupole and octupole resonances. Whereas the giant states exhibit the well known distortions of the Fermi sphere already at the classical level we find that the low lying 3 - state has an isotropic pressure tensor in the Planck's constant #-> # 0 limit. Quantum corrections reestablish a small distortion and thus a finite restoring force

  17. Nuclear structure of Ra at high spin

    Indian Academy of Sciences (India)

    However, nuclear structure at high spin and excitation energies (∼ 6 MeV) would require a coupling of excited 1p–1h with 208Pb core. The coupling between single- particle orbitals and collective vibrations of core complicates the simple shell model picture. With increasing neutron number, Ra isotopes show an abrupt ...

  18. Spatial discrimination against background with different optical systems for collection of fluorescence in laser-excited atomic fluorescence spectrometry with a graphite tube electrothermal atomizer.

    Science.gov (United States)

    Yuzefovsky, A I; Lonardo, R F; Michel, R G

    1995-07-01

    A single 90 degrees off-axis ellipsoidal mirror fragment was used in a dispersive detection system for electrothermal atomization laser-excited atomic fluorescence spectrometry. The performance of the new optical arrangement was compared with those of optical arrangements that employed a plane mirror in combination with biconvex or plano-convex lenses. All the optical arrangements collected fluorescence in a scheme called front surface illustration. BEAM-4, an optical ray tracing program, was used for calculations of spatial ray distributions and optical collection efficiency for the various optical configurations. Experimentally, the best collection efficiency was obtained by use of the ellipsoidal mirror, in qualitative agreement with simulations done by use of the BEAM-4 software. The best detection limit for cobalt with the new optical arrangement was 20 fg, which was a factor of 5 better than that obtained with conventional optical arrangements with otherwise the same instrumentation. The signal-to-background ratio and the fluorescence collection efficiency were also studied as a function of position of the optical components for the various optical arrangements. For both cobalt and phosphorus, the signal-to-background ratio with the new optical arrangement remained stable within 10-20% during +/- 8 mm shifts in the position of the detection system from the focal plane of the optics. Overall, the new optical arrangement offered high collection efficiency, excellent sensitivity, and facile optical alignment due to efficient spatial separation between the fluorescence signal and the background radiation. The advantages of the new optical arrangement were particularly important during measurements in the presence of high levels of blackbody radiation.

  19. Excitation functions of alpha particles induced nuclear reactions on natural titanium in the energy range of 10.4–50.2 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Usman, Ahmed Rufai [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Department of Physics, Umaru Musa Yar' adua University, Katsina (Nigeria); Khandaker, Mayeen Uddin, E-mail: mu_khandaker@um.edu.my [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Haba, Hiromitsu [Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Otuka, Naohiko [Nuclear Data Section, Division of Physical and Chemical Sciences, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, A-1400 Vienna (Austria); Murakami, Masashi [Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan)

    2017-05-15

    Highlights: • Detailed presentation of new results on experimental cross-sections of {sup nat}Ti(α,x) processes. • Calculations of thick target yields for scandium and other radionuclides via the {sup nat}Ti(α,x) production route. • Comparison with TENDL-2015 library. • Detailed review of previous experimental data. - Abstract: We studied the excitation functions of residual radionuclide productions from α particles bombardment on natural titanium in the energy range of 10.4–50.2 MeV. A well-established stacked-foil activation technique combined with HPGe γ-ray spectrometry was used to measure the excitation functions for the {sup 51,49,48}Cr, {sup 48}V, {sup 43}K, and {sup 43,44m,44g,46g+m,47,48}Sc radionuclides. The thick target yields for all assessed radionuclides were also calculated. The obtained experimental data were compared with the earlier experimental ones and also with the evaluated data in the TENDL-2015 library. A reasonable agreement was found between this work and some of the previous ones, while a partial agreement was found with the evaluated data. The present results would further enrich the experimental database and facilitate the understanding of existing discrepancies among the previous measurements. The results would also help to enhance the prediction capability of the nuclear reaction model codes.

  20. Respective efficiencies of nuclear collisions and electronic excitations for precipitating Ag clusters in sol-gel films

    CERN Document Server

    Pivin, J C

    2002-01-01

    The growth of silver clusters in co-sputtered SiO sub 2 :Ag films under irradiation with increasing fluences of 1.5 MeV He or 3 MeV Au ions is investigated by recording spectra of optical extinction. The analysis of surface plasmon resonances in these very small clusters on basis of Mie theory permits to estimate more precisely their mean size than TEM images. A linear increase of the mean cluster size with the energy deposited by ions in electronic excitations and little effect of collision cascades are observed. The growth kinetics is ascribed to a process of desorption/re-adsorption of Ag atoms at the surface of clusters.

  1. Observation of gamma-rays from fallout collected at Ibaraki, Japan, during the Fukushima nuclear accident.

    Science.gov (United States)

    Saegusa, Jun; Kikuta, Yasuaki; Akino, Hitoshi

    2013-07-01

    Gamma-ray pulse height distributions were measured for a fallout sample collected at Ibaraki, Japan, during the Fukushima accident in March 2011. The fallout was collected in a pan of water and then evaporated to dryness on a stainless-steel holder. The sample was measured by a germanium detector three times over a year. In the pulse height distribution of the initial measurement, approximately 140 peaks were observed in the 50-2048 keV energy region. Most of these peaks were either total absorption peaks or sum peaks of Te, I or Cs isotopes. Unlike fallout samples at the past nuclear accidents, nuclides such as Ce and Ru were not detected whereas (110m)Ag was prominently observed. The radioactivity concentration of (137)Cs was determined to be at least 1.4×10(4) Bq m(-2), approximately 14% of which was attributed to rainout. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Production of a diffuse very high reflectivity material for light collection in nuclear detectors

    CERN Document Server

    Pichler, B J; Mirzoyan, R; Weiss, L; Ziegler, S I

    2000-01-01

    A diffuse very high reflectivity material, based on polytetrafluorethylene (PTFE) for optimization of light-collection efficiency has been developed. PTFE powder was used to produce reflector block material. The powder was pressed with 525 kPa in a form and sintered at 375 deg. C. The reflectivity was above 98% within the spectral range from 350 to 1000 nm. The blocks of this material are machinable with saws, drilling and milling machines. The reflector is used as a housing for scintillating crystals in a nuclear medicine application (small animal positron emission tomograph). It is also used as a light collector in very high-energy gamma-ray astrophysicas experiments, HEGRA and MAGIC. The application of this inexpensive, easy to make diffuse reflector may allow the optimization of light collection in a wide range of low-level light-detector configurations.

  3. Path-integral in collective variables and its application to nuclear and hadron physics

    International Nuclear Information System (INIS)

    Pervushin, V.N.; Rajnkhardt, Kh.; Ehbert, D.

    1979-01-01

    The application of functional integrals to describe collective degrees of freedom in different fields of physics is reviewed for the period since 1965. The application of path integrals to the schematic model of nuclear multiparticle systems with pairing and particle-hole forces permits to lay strict foundations under the so called theory of nuclear field, which hitherto was proved euristically. The Abel gauge theory of interacting massless quarks and vector gluons is described. In this model radiative corrections cause spontaneous dynamic breaking of the chiral γ 5 -invariance. The application of functional integration to two-dimensional quantum chromodynamics is also analyzed. It is shown that the local quark-gluon theory can be transformed in an infinite-component nonpolynomial field theory in terms of colourless bound states - mesons. A modified perturbation theory appears in the form of 1/Nsub(c)-expansion (Nsub(c) - number of quarks), that is formally is very akin to the 1/Ω-expansion (Ωdegeneracy of single-particle states) in the theory of nuclear field

  4. Collection and Analysis of Open Source News for Information Awareness and Early Warning in Nuclear Safeguards

    International Nuclear Information System (INIS)

    Cojazzi, Giacomo G.M.; Van Der Goot, Erik; Verile, Marco; Wolfart, Erik; Rutan Fowler, Marcy; Feldman, Yana; Hammond, William; Schweighardt, John; Ferguson, Mattew

    2013-01-01

    Acquisition and analysis of open source information plays an increasingly important role in the IAEA’s move towards safeguards implementation based on all safeguards relevant information known about a State. The growing volume of open source information requires the development of technology and tools capable of effectively collecting relevant information, filtering out “noise”, organizing valuable information in a clear and accessible manner, and assessing its relevance. In this context, the IAEA’s Division of Information Management (SGIM) and the EC’s Joint Research Centre (JRC) are currently implementing a joint project to advance the effectiveness and efficiency of the IAEA’s workflow for open source information collection and analysis. The objective is to provide tools to support SGIM in the production of the SGIM Open Source Highlights, which is a daily news brief consisting of the most pertinent news stories relevant to safeguards and non-proliferation. The process involves the review and selection of hundreds of articles from a wide array of specifically selected sources. The joint activity exploits the JRC’s Europe Media Monitor (EMM) and NewsDesk applications: EMM automatically collects and analyses news articles from a pre-defined list of web sites, and NewsDesk allows an analyst to manually select the most relevant articles from the EMM stream for further processing. The paper discusses the IAEA’s workflow for the production of SGIM Open Source Highlights and describes the capabilities of EMM and NewsDesk. It then provides an overview of the joint activities since the project started in 2011, which were focused i) on setting up a separate EMM installation dedicated to the nuclear safeguards and security domain (Nuclear Security Media Monitor, NSMM) and ii) on evaluating the NSMM/NewsDesk for meeting the IAEA’s needs. Finally, it presents the current use NSMM/NewsDesk at the IAEA and proposes options for further integration with the

  5. Spurious Excitations in Semiclassical Scattering Theory.

    Science.gov (United States)

    Gross, D. H. E.; And Others

    1980-01-01

    Shows how through proper handling of the nonuniform motion of semiclassical coordinates spurious excitation terms are eliminated. An application to the problem of nuclear Coulomb excitation is presented as an example. (HM)

  6. Excitation function of the alpha particle induced nuclear reactions on enriched {sup 116}Cd, production of the theranostic isotope {sup 117m}Sn

    Energy Technology Data Exchange (ETDEWEB)

    Ditrói, F., E-mail: ditroi@atomki.hu [Institute for Nuclear Research, Hungarian Academy of Sciences, Debrecen (Hungary); Takács, S. [Institute for Nuclear Research, Hungarian Academy of Sciences, Debrecen (Hungary); Haba, H.; Komori, Y. [RIKEN Nishina Center, Tokyo (Japan); Aikawa, M. [Graduate School of Science, Hokkaido University, Sapporo (Japan); Szűcs, Z. [Institute for Nuclear Research, Hungarian Academy of Sciences, Debrecen (Hungary); Saito, M. [Graduate School of Science, Hokkaido University, Sapporo (Japan)

    2016-10-15

    Highlights: • Alpha induced nuclear reactions on enriched {sup 116}Cd up to 51 MeV. • Electro-deposited target with Cu backing. • Comparison with the EMPIRE 3.2 and TENDL-2015 calculations. • Physical yield. • {sup 117m}Sn theranostic radioisotope. - Abstract: {sup 117m}Sn is one of the radioisotopes can be beneficially produced through alpha particle irradiation. The targets were prepared by deposition of {sup 116}Cd metal onto high purity 12 μm thick Cu backing. The average deposited thickness was 21.9 μm. The beam energy was thoroughly measured by Time of Flight (TOF) methods and proved to be 51.2 MeV. For the experiment the well-established stacked foil technique was used. In addition to the Cd targets, Ti foils were also inserted into the stacks for energy and intensity monitoring. The Cu backings were also used for monitoring and as recoil catcher of the reaction products from the cadmium layer. The activities of the irradiated foils were measured with HPGe detector for gamma-ray spectrometry and cross section values were determined. As a result excitation functions for the formation of {sup 117m}Sn, {sup 117m,g}In, {sup 116m}In, {sup 115m}In and {sup 115m,g}Cd from enriched {sup 116}Cd were deduced and compared with the available literature data and with the results of the nuclear reaction model code calculations EMPIRE 3.2 and TALYS 1.8. Yield curves were also deduced for the measured nuclear reactions and compared with the literature.

  7. Can Measured Synergy Excitations Accurately Construct Unmeasured Muscle Excitations?

    Science.gov (United States)

    Bianco, Nicholas A; Patten, Carolynn; Fregly, Benjamin J

    2018-01-01

    Accurate prediction of muscle and joint contact forces during human movement could improve treatment planning for disorders such as osteoarthritis, stroke, Parkinson's disease, and cerebral palsy. Recent studies suggest that muscle synergies, a low-dimensional representation of a large set of muscle electromyographic (EMG) signals (henceforth called "muscle excitations"), may reduce the redundancy of muscle excitation solutions predicted by optimization methods. This study explores the feasibility of using muscle synergy information extracted from eight muscle EMG signals (henceforth called "included" muscle excitations) to accurately construct muscle excitations from up to 16 additional EMG signals (henceforth called "excluded" muscle excitations). Using treadmill walking data collected at multiple speeds from two subjects (one healthy, one poststroke), we performed muscle synergy analysis on all possible subsets of eight included muscle excitations and evaluated how well the calculated time-varying synergy excitations could construct the remaining excluded muscle excitations (henceforth called "synergy extrapolation"). We found that some, but not all, eight-muscle subsets yielded synergy excitations that achieved >90% extrapolation variance accounted for (VAF). Using the top 10% of subsets, we developed muscle selection heuristics to identify included muscle combinations whose synergy excitations achieved high extrapolation accuracy. For 3, 4, and 5 synergies, these heuristics yielded extrapolation VAF values approximately 5% lower than corresponding reconstruction VAF values for each associated eight-muscle subset. These results suggest that synergy excitations obtained from experimentally measured muscle excitations can accurately construct unmeasured muscle excitations, which could help limit muscle excitations predicted by muscle force optimizations.

  8. Estimating collective dose in nuclear facilities, with emphasis on the design process

    International Nuclear Information System (INIS)

    Cohen, S.; Mann, B.

    1987-01-01

    The report presents a more accurate, systematic method than has been available previously for predicting worker doses which might be incurred during routine and non-routine work in radioactive areas. Besides assisting regulators with an analysis of the ''potential impact on radiological exposures of facility employees'' now required under the new backfit rule (10 CFR 50.109c), this predictive model will also help licensees conserve dollars as well as dose because it can be employed very early in the engineering design phase of a modification, when adjustments can still be made easily to change orders. Such early estimates make good business sense because they will facilitate planning, labor loading, costing, resource and equipment scheduling, and overall coordination of both single and repetitive projects. Also, with the support of corporate management, radiation protection coordinators can introduce the model into training programs to acquaint design engineers and others with dose calculation techniques. The importance assigned by nuclear industry senior management to the principle of ALARA and the reduction of collective worker dose is measured, in large part, by demonstrated efforts to integrate the control of radiation exposure fully into the overall planning function of nuclear facility management. That integration will be fostered through the use of this approach

  9. Aerosols from metal cutting techniques typical of decommissioning nuclear facilities - experimental system for collection and characterization

    International Nuclear Information System (INIS)

    Newton, G.J.; Hoover, M.D.; Barr, E.B.; Wong, B.A.; Ritter, P.D.

    1982-01-01

    Decommissioning of radioactively contaminated sites has the potential for creating radioactive and other potentially toxic aerosols. We describe an experimental system to collect and characterize aerosols from metal cutting activities typical of those used in decommissioning of nuclear facilities. A special enclosure was designed for the experiment and consisted of a 5.1 cm x 10.2 cm stud frame with double walls of flame retardant polyethylene film. Large plexiglass windows allowed the cutting operations to be directed and filmed. Ventilation was 8500 liters/minute (300 CFM) exhausted through HEPA filters. Seven cutting techniques were evaluated: pipe cutter, reciprocating saw, band saw, chop saw, oxy-acetylene torch, electric arc cut rod and plasma torch. Two grinding tools were also evaluated. Materials cut were 5.1 cm, 7.6 cm and 10.2 cm diameter schedule 40, 80 and 180 type 304L stainless steel pipe

  10. Collection of articles of the 5-th Conference of the Ukrainian Nuclear Society 'Youth to nuclear power'

    International Nuclear Information System (INIS)

    Barbashev, S.V.

    2001-01-01

    Large scope of problems is presented. Operation of nuclear power enterprises, introduction of safety culture principles in them, situation with the training of specialists, role of youth in nuclear fuel complex and others are discussed. Reports of participants which were submitted at the conference are presented

  11. Study of Nuclear Collisions of 86 MeV/a.m.u. $^{12}$C with Heavy Targets by Collection of the Heavy Recoil Nuclei

    CERN Multimedia

    2002-01-01

    The aim of this experiment is twofold:\\\\ \\\\ Firstly to test the possibilities of collection of the heavy recoil nuclei with the device presented schematically on the figure. The recoil nuclei escaping from the irradiated target are first thermalised in a gas (N^2). One then takes advantage of their remaining charge to collect them with an electric field on the surface of a solid state detector. Tests already performed with other beams give absolute efficiency around 5\\%. The best conditions of collections with very energetic |1|2C have first to be tested. Secondly to get some insight into nuclear reaction mechanisms induced by 86~MeV/a.m.u. |1|2C using the possibilities of this recoil chamber. Two kinds of mechanisms should occur in these interactions. If the incident energy is damped (deep inelastic reaction, fusion), the heavy nucleus will be highly excited and the residual nuclei will lie along the @G^n/@G^p~=~1~line. For heavy nuclei this line is located at about 25~mass units from the stability line. If ...

  12. Excited states 4

    CERN Document Server

    Lim, Edward C

    2013-01-01

    Excited States, Volume 4 is a collection of papers that deals with the excited states of molecular activity. One paper investigates the resonance Raman spectroscopy as the key to vibrational-electronic coupling. This paper reviews the basic theory of Raman scattering; it also explains the derivation of the Raman spectra, excitation profiles, and depolarization ratios for simple resonance systems. Another paper reviews the magnetic properties of triplet states, including the zero-field resonance techniques, the high-field experiments, and the spin Hamiltonian. This paper focuses on the magnetic

  13. The collection of symposium reports for people to understand nuclear power

    International Nuclear Information System (INIS)

    1988-07-01

    It deals with the symposium reports which gives people public information on nuclear power. It introduces the programs on public information and measures in France, Japan, Canada, Korea. It reports the presentations of the result which are the education programs for children and people about safety of nuclear power, nuclear power plant and environmental disruption, safety insurance of nuclear power and the present condition of operating nuclear power plant.

  14. Size distribution of radioactive particles collected at Tokai, Japan 6 days after the nuclear accident.

    Science.gov (United States)

    Miyamoto, Yutaka; Yasuda, Kenichiro; Magara, Masaaki

    2014-06-01

    Airborne radioactive particles released by the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident in 2011 were collected with a cascade low-pressure impactor at the Japan Atomic Energy Agency (JAEA) in Tokai, Japan, 114 km south of the FDNPP. Size-fractionated samples were collected twice, in the periods of March 17-April 1, 2011, and May 9-13, 2011. These size-fractionated samplings were carried out in the earliest days at a short distance from the FDNPP. Radioactivity of short-lived nuclides (several ten days of half-life) was determined as well as (134)Cs and (137)Cs. The elemental composition of size-fractionated samples was also measured. In the first collection, the activity median aerodynamic diameter (AMAD) of (129m)Te, (140)Ba, (134)Cs, (136)Cs and (137)Cs was 1.5-1.6 μm, while the diameter of (131)I was 0.45 μm. The diameters of (134)Cs and (137)Cs in the second collection were expressed as three peaks at <0.5 μm, 0.94 μm, and 7.8 μm. The (134)Cs/(137)Cs ratio of the first collection was 1.02 in total, but the ratio in the fine fractions was 0.91. A distribution map of (134)Cs/(137)Cs - (136)Cs/(137)Cs ratios was helpful in understanding the change of radioactive Cs composition. The Cs composition of size fractions <0.43 μm and the composition in the 1.1-2.1 μm range (including the AMAD of 1.5-1.6 μm) were similar to the calculated compositions of fuels in the reactors No. 1 and No. 3 at the FDNPP using the ORIGEN-II code. The Cs composition collected in May, 2011 was similar to the calculation results of reactor No. 2 fuel composition. The change of Cs composition implies that the radioactive Cs was released from the three reactors at the FDNPP via different processes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Basis states for the rotational and vibrational limits of nuclear collective motion

    International Nuclear Information System (INIS)

    Vanagas, V.; Alishauskas, S.; Kalinauskas, R.; Nadzhakov, E.

    1980-01-01

    Basis states characterized by quantum numbers traditionally used in the rotational and the vibrational limits are treated in an unified way. An explicit basis construction in the Hilbert space of the collective phenomenological nuclear Hamiltonian generalized to six degrees of freedom in both limits is given. This generalization reduces to including an additional degree of freedom allowing to treat both cases within a collective substance of the complete many-body Hilbert space. A group-theoretical approach is applied. From this point of view the problem is reduced to the construction of a set of U(6)-irreducible states labelled by quantum numbers of two special chains of subgroups adapted for the rotational and vibrational limits. In particular, the generalization is more complicated in the case of the chain for the rotational limits. The explicit construction of a basis for both limits is carried out in two steps: 1) construction of the highest weight state for corresponding group irreducible representation - in the case of the rotational limit U(3) and of the vibrational limit O(5); 2) generating a complete set of states by the projection technique. In this framework it is possible to diagonalize a general phenomenological Hamiltonian in cases different from both limits. It is also possible to calculate transition probabilities induced by any physical quantity

  16. Improving the description of collective effects within the combinatorial model of nuclear level densities

    International Nuclear Information System (INIS)

    Hilaire, S.; Girod, M.; Goriely, S.

    2011-01-01

    The combinatorial model of nuclear level densities has now reached a level of accuracy comparable to that of the best global analytical expressions without suffering from the limits imposed by the statistical hypothesis on which the latter expressions rely. In particular, it provides naturally, non Gaussian spin distribution as well as non equipartition of parities which are known to have a significant impact on cross section predictions at low energies. Our first global model developed in Ref. 1 suffered from deficiencies, in particular in the way the collective effects - both vibrational and rotational - were treated. We have recently improved this treatment using simultaneously the single particle levels and collective properties predicted by a newly derived Gogny interaction, therefore enabling a microscopic description of energy-dependent shell, pairing and deformation effects. In addition, for deformed nuclei, the transition to sphericity is coherently taken into account on the basis of a temperature-dependent Hartree-Fock calculation which provides at each temperature the structure properties needed to build the level densities. This new method is described and shown to give promising preliminary results with respect to available experimental data. (authors)

  17. Programs OPTMAN and SHEMMAN Version 6 (1999) - Coupled-Channels optical model and collective nuclear structure calculation -

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Jong Hwa; Lee, Jeong Yeon; Lee, Young Ouk; Sukhovitski, Efrem Sh. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2000-01-01

    Programs SHEMMAN and OPTMAN (Version 6) have been developed for determinations of nuclear Hamiltonian parameters and for optical model calculations, respectively. The optical model calculations by OPTMAN with coupling schemes built on wave functions functions of non-axial soft-rotator are self-consistent, since the parameters of the nuclear Hamiltonian are determined by adjusting the energies of collective levels to experimental values with SHEMMAN prior to the optical model calculation. The programs have been installed at Nuclear Data Evaluation Laboratory of KAERI. This report is intended as a brief manual of these codes. 43 refs., 9 figs., 1 tabs. (Author)

  18. Experimental measurements and nuclear model calculations on the excitation functions of $^{nat}Ce(^{3}He, xn)$ and $^{141}$therapeutic radionuclide $^{140}$Nd

    CERN Document Server

    Hilgers, K; Coenen, H H; Qaim, S M

    2005-01-01

    For production of the therapy related Auger electron emitting neutron deficient nuclide /sup 140/Nd (T/sub fraction 1/2/=3.37d) two routes were investigated: the nuclear reaction range from 15 to 36 MeV and the reaction /sup 141/Pr(p,2n)/sup 140isotopes, namely /sup 139/Nd and /sup 141/Nd, as well as to cerium(IV)-oxide and praseodymium (III)-oxide were obtained by sedimentation and the conventional stacked-foil technique was used for cross section measurements. All the experimental data obtained in this work were compared with the results of theoretical calculations using the exciton model code ALICE-IPPE as well as with literature experimental data, if available. In general, good agreement between experimental and theoretical results was found. The theoretical thick target yields of all the product nuclides were calculated from the measured excitation functions. The theoretical thick target yield of amounts to 12 MBq/mu Acenterdoth and over the energy range E/sub p/=30rightward arrow15 Me V to 210 MBq/mu; A...

  19. SU-F-J-100: Standardized Biodistribution Template for Nuclear Medicine Dosimetry Collection and Reporting

    Energy Technology Data Exchange (ETDEWEB)

    Kesner, A [University of Colorado, Anschutz Medical Campus, Aurora, Colorado (United States); Poli, G [International Atomic Energy Agency, Vienna, Vienna (Austria); Beykan, S; Lassman, M [University of Wuerzburg, Wuerzberg, Wuerzberg (Germany)

    2016-06-15

    Purpose: As the field of Nuclear Medicine moves forward with efforts to integrate radiation dosimetry into clinical practice we can identify the challenge posed by the lack of standardized dose calculation methods and protocols. All personalized internal dosimetry is derived by projecting biodistribution measurements into dosimetry calculations. In an effort to standardize organization of data and its reporting, we have developed, as a sequel to the EANM recommendation of “Good Dosimetry Reporting”, a freely available biodistribution template, which can be used to create a common point of reference for dosimetry data. It can be disseminated, interpreted, and used for method development widely across the field. Methods: A generalized biodistribution template was built in a comma delineated format (.csv) to be completed by users performing biodistribution measurements. The template is available for free download. The download site includes instructions and other usage details on the template. Results: This is a new resource developed for the community. It is our hope that users will consider integrating it into their dosimetry operations. Having biodistribution data available and easily accessible for all patients processed is a strategy for organizing large amounts of information. It may enable users to create their own databases that can be analyzed for multiple aspects of dosimetry operations. Furthermore, it enables population data to easily be reprocessed using different dosimetry methodologies. With respect to dosimetry-related research and publications, the biodistribution template can be included as supplementary material, and will allow others in the community to better compare calculations and results achieved. Conclusion: As dosimetry in nuclear medicine become more routinely applied in clinical applications, we, as a field, need to develop the infrastructure for handling large amounts of data. Our organ level biodistribution template can be used as a

  20. Voiced Excitations

    National Research Council Canada - National Science Library

    Holzricher, John

    2004-01-01

    To more easily obtain a voiced excitation function for speech characterization, measurements of skin motion, tracheal tube, and vocal fold, motions were made and compared to EM sensor-glottal derived...

  1. Excited states

    CERN Document Server

    Lim, Edward C

    1974-01-01

    Excited States, Volume I reviews radiationless transitions, phosphorescence microwave double resonance through optical spectra in molecular solids, dipole moments in excited states, luminescence of polar molecules, and the problem of interstate interaction in aromatic carbonyl compounds. The book discusses the molecular electronic radiationless transitions; the double resonance techniques and the relaxation mechanisms involving the lowest triplet state of aromatic compounds; as well as the optical spectra and relaxation in molecular solids. The text also describes dipole moments and polarizab

  2. Theoretical studies of excited states of heavy nuclei with large neutron excess

    International Nuclear Information System (INIS)

    Wiboolsake, S.

    1996-01-01

    Certain neutron excess heavy nuclei have a thick neutron skin on the nuclear surface. In this paper detailed collective densities excitations in heavy nuclei with a large neutron excess and a thick neutron skin will be considered within the framework of the 'hydrodynamic' model. It will be shown that low energy isoscalar excitations are possible. The knowledge obtained will give information on the neutron thickness, the compressibility and the surface tension of neutron excess at low density

  3. Estimated collective effective dose to the population from X-ray and nuclear medicine examinations in Finland.

    Science.gov (United States)

    Bly, R; Järvinen, H; Korpela, M H; Tenkanen-Rautakoski, P; Mäkinen, A

    2011-09-01

    The collective effective doses to the population from X-ray and nuclear medicine (NM) examinations in Finland in 2008 and 2009, respectively, were estimated. The estimated collective effective dose per inhabitant was 0.45 mSv from X-ray examinations and 0.03 mSv from NM examinations. The collective effective doses per inhabitant have not changed substantially during the last 10 y. However, proportional dose due to CT examinations has increased from 50 % in 2005 to 58 % in 2009 of the total collective effective dose from all X-ray examinations and proportional dose of PET examinations from 7 to 13 % of the total collective effective dose from NM examinations. The collective effective dose from conventional plain radiography was over 20 % higher when estimated using the new (ICRP 103) tissue weighting factors than that obtained using the old (ICRP 60) tissue weighting factors.

  4. In-plant reliability data base for nuclear power plant components: data collection and methodology report

    International Nuclear Information System (INIS)

    Drago, J.P.; Borkowski, R.J.; Pike, D.H.; Goldberg, F.F.

    1982-07-01

    The development of a component reliability data for use in nuclear power plant probabilistic risk assessments and reliabiilty studies is presented in this report. The sources of the data are the in-plant maintenance work request records from a sample of nuclear power plants. This data base is called the In-Plant Reliability Data (IPRD) system. Features of the IPRD system are compared with other data sources such as the Licensee Event Report system, the Nuclear Plant Reliability Data system, and IEEE Standard 500. Generic descriptions of nuclear power plant systems formulated for IPRD are given

  5. Research and nuclear wastes. An interdisciplinary reflection, document collective risk and crisis situation, no. 5

    International Nuclear Information System (INIS)

    Gilbert, C.

    2006-01-01

    During the year 2005, scientists discussed and exchanged their point of view on the forecast of the nuclear wastes. Then a seminar took place during summer 2005 on the ''contribution to the debate on the nuclear wastes management future''. This synthesis aims to present the exchanges of this seminar, grouped around 8 main questions: Have the spent fuel to be reprocessing? Is the geological disposal imperative? The reversibility? The transmutation? Is ''the open research'' on wastes, a necessity, an alibi or a problem? The public anxiety or the anxiety of the public? Can we debate on the nuclear wastes regardless of the nuclear program choice? (A.L.B.)

  6. Theoretical research in nuclear structure and nuclear collective motion: Progress report for the period March 1, 1988--February 29, 1989

    International Nuclear Information System (INIS)

    Klein, A.

    1989-01-01

    This paper discusses the following topics: Large amplitude collective motion; Boson mappings of shell model algebras; Semiclassical approximations, TDHF, and heavy ion scattering; New approach to effective interactions; and Bound states in quantum electrodynamics

  7. New results on multiple excitations of giant resonances

    International Nuclear Information System (INIS)

    Mordechai, S.; Texas Univ., Austin, TX; Moore, C.F.

    1993-01-01

    Exotic excitations like the double giant dipole were predicted for many years but not observed experimentally until recently. Several experiments have been carried out at Los Alamos National laboratory to search for these new collective modes of the nucleus. The results discover two previously unobserved types of double giant resonances. This work presents the recent pion double charge exchange data and the analysis that support the existence of two such exotic vibrational nuclear modes

  8. Materials of the Annual Scientific Conference at the Institute for Nuclear Research. (Collected reports)

    International Nuclear Information System (INIS)

    Vishnevs'kij, Yi.M.; Ostashko, V.V.

    1995-01-01

    The proceeding contain contributed papers submitted to the annual Scientific conference of the Institute for Nuclear Research, Ukraine (kiev, January 1996). The proceedings include reports have been presented on the following sections: Nuclear physics, Solid State physics, Plasma physics, Radio ecology, Reactor safety, Radiation and reactor materials Study. The book is a direct reproduction of the print-ready manuscripts presented by the authors. No corrections have been made in the texts

  9. Nuclear morphometry in histological specimens of canine prostate cancer: Correlation with histological subtypes, Gleason score, methods of collection and survival time.

    Science.gov (United States)

    Di Donato, Guido; Laufer-Amorim, Renée; Palmieri, Chiara

    2017-10-01

    Ten normal prostates, 22 benign prostatic hyperplasia (BPH) and 29 prostate cancer (PC) were morphometrically analyzed with regard to mean nuclear area (MNA), mean nuclear perimeter (MNP), mean nuclear diameter (MND), coefficient of variation of the nuclear area (NACV), mean nuclear diameter maximum (MDx), mean nuclear diameter minimum (MDm), mean nuclear form ellipse (MNFe) and form factor (FF). The relationship between nuclear morphometric parameters and histological type, Gleason score, methods of sample collection, presence of metastases and survival time of canine PC were also investigated. Overall, nuclei from neoplastic cells were larger, with greater variation in nuclear size and shape compared to normal and hyperplastic cells. Significant differences were found between more (small acinar/ductal) and less (cribriform, solid) differentiated PCs with regard to FF (pnuclear morphometric analysis in combination with Gleason score can help in canine prostate cancer grading, thus contributing to the establishment of a more precise prognosis and patient's management. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Guide on a national system for collecting, assessing and disseminating information on safety-related events in nuclear power plants

    International Nuclear Information System (INIS)

    1983-02-01

    There is a wide spectrum of safety significance in the events that can occur during nuclear power plant operations. It is important that lessons be learned from safety-related events (hereinafter referred to as unusual events) so as to improve the safety of nuclear power plants. Hence formal procedures should be established for this purpose. The purpose of this document is to provide guidance to Member States for establishing a system (hereinafter referred to as a national system) for collecting, storing, retrieving, assessing and disseminating information on unusual events in nuclear power plants. The guidance given is based on experience gained in the use of existing national and international systems. This guide covers a national system that is part of a programme to improve nuclear power plant safety using experience gained from operating plants both within and outside the country. Implementing the recommendations in this guide would render any national system compatible with other national systems and facilitate the participation in the IAEA System for Reporting Unusual Events with Safety Significance (hereinafter referred to as the IAEA Incident Reporting System, IAEA-IRS) for more widespread dissemination of lessons learned from nuclear power plant operation

  11. Nuclear-Pumped Lasers. [efficient conversion of energy liberated in nuclear reactions to coherent radiation

    Science.gov (United States)

    1979-01-01

    The state of the art in nuclear pumped lasers is reviewed. Nuclear pumped laser modeling, nuclear volume and foil excitation of laser plasmas, proton beam simulations, nuclear flashlamp excitation, and reactor laser systems studies are covered.

  12. Are both sympatric species Ilex perado and Ilex canariensis secretly hybridizing? Indication from nuclear markers collected in Tenerife

    Directory of Open Access Journals (Sweden)

    Manen Jean-François

    2004-11-01

    Full Text Available Abstract Background Intra-specific and intra-individual polymorphism is frequently observed in nuclear markers of Ilex (Aquifoliaceae and discrepancy between plastid and nuclear phylogenies is the rule in this genus. These observations suggest that inter-specific plastid or/and nuclear introgression played an important role in the process of evolution of Ilex. With the aim of a precise understanding of the evolution of this genus, two distantly related sympatric species collected in Tenerife (Canary Islands, I. perado and I. canariensis, were studied in detail. Introgression between these two species was previously never reported. One plastid marker (the atpB-rbcL spacer and two nuclear markers, the ribosomal internal transcribed spacer (ITS and the nuclear encoded plastid glutamine synthetase (nepGS were analyzed for 13 and 27 individuals of I. perado and I. canariensis, respectively. Results The plastid marker is intra-specifically constant and correlated with species identity. On the other hand, whereas the nuclear markers are conserved in I. perado, they are highly polymorphic in I. canariensis. The presence of pseudogenes and recombination in ITS sequences of I. canariensis explain this polymorphism. Ancestral sequence polymorphism with incomplete lineage sorting, or past or recent hybridization with an unknown species could explain this polymorphism, not resolved by concerted evolution. However, as already reported for many other plants, past or recent introgression of an alien genotype seem the most probable explanation for such a tremendous polymorphism. Conclusions Data do not allow the determination with certitude of the putative species introgressing I. canariensis, but I. perado is suspected. The introgression would be unilateral, with I. perado as the male donor, and the paternal sequences would be rapidly converted in highly divergent and consequently unidentifiable pseudogenes. At least, this study allows the establishment of

  13. Excited baryons

    Energy Technology Data Exchange (ETDEWEB)

    Mukhopadhyay, N.C.

    1986-01-01

    The status of the theory of the low-energy approach to hadron structure is reviewed briefly by surveying a few relevant models. A few examples of tests needed to sort out the predictions of different models pertaining to the quark-gluon structure of hadrons are discussed, and given the resulting physics objectives, a few experimental options for excited baryon research at CFBAF are suggested. (LEW)

  14. Excited baryons

    International Nuclear Information System (INIS)

    Mukhopadhyay, N.C.

    1986-01-01

    The status of the theory of the low-energy approach to hadron structure is reviewed briefly by surveying a few relevant models. A few examples of tests needed to sort out the predictions of different models pertaining to the quark-gluon structure of hadrons are discussed, and given the resulting physics objectives, a few experimental options for excited baryon research at CFBAF are suggested

  15. Onset of collectivity in neutron-rich Sr and Kr isotopes: Prompt spectroscopy after Coulomb excitation at REX-ISOLDE, CERN

    Directory of Open Access Journals (Sweden)

    Clément E.

    2013-12-01

    Full Text Available A rapid onset of quadrupole deformation is known to occur around the neutron number 60 in the neutron-rich Zr and Sr isotopes. This shape change has made the neutron-rich A = 100 region an active area of experimental and theoretical studies for many decades now. We report in this contribution new experimental results in the neutron rich 96,98Sr investigated by safe Coulomb excitation of radioactive beams at the REX-ISOLDE facility, CERN. Reduced transition probabilities and spectroscopic quadrupole moments have been extracted from the differential Coulomb excitation cross section supporting the scenario of shape coexistence/change at N = 60. Future perspectives are presented including the recent experimental campaign performed at ILL-Grenoble.

  16. Third-generation site characterization: Cryogenic core collection, nuclear magnetic resonance, and electrical resistivity

    Science.gov (United States)

    Kiaalhosseini, Saeed

    In modern contaminant hydrology, management of contaminated sites requires a holistic characterization of subsurface conditions. Delineation of contaminant distribution in all phases (i.e., aqueous, non-aqueous liquid, sorbed, and gas), as well as associated biogeochemical processes in a complex heterogeneous subsurface, is central to selecting effective remedies. Arguably, a factor contributing to the lack of success of managing contaminated sites effectively has been the limitations of site characterization methods that rely on monitoring wells and grab sediment samples. The overarching objective of this research is to advance a set of third-generation (3G) site characterization methods to overcome shortcomings of current site characterization techniques. 3G methods include 1) cryogenic core collection (C3) from unconsolidated geological subsurface to improve recovery of sediments and preserving key attributes, 2) high-throughput analysis (HTA) of frozen core in the laboratory to provide high-resolution, depth discrete data of subsurface conditions and processes, 3) resolution of non-aqueous phase liquid (NAPL) distribution within the porous media using a nuclear magnetic resonance (NMR) method, and 4) application of a complex resistivity method to track NAPL depletion in shallow geological formation over time. A series of controlled experiments were conducted to develop the C 3 tools and methods. The critical aspects of C3 are downhole circulation of liquid nitrogen via a cooling system, the strategic use of thermal insulation to focus cooling into the core, and the use of back pressure to optimize cooling. The C3 methods were applied at two contaminated sites: 1) F.E. Warren (FEW) Air Force Base near Cheyenne, WY and 2) a former refinery in the western U.S. The results indicated that the rate of core collection using the C3 methods is on the order of 30 foot/day. The C3 methods also improve core recovery and limits potential biases associated with flowing sands

  17. Nuclear and conventional techniques applied to the analysis of Purhepecha metals of the Pareyon collection

    International Nuclear Information System (INIS)

    Mendez, U.; Tenorio C, D.; Ruvalcaba, J.L.; Lopez, J.A.

    2005-01-01

    The main objective of this investigation was to determine the composition and microstructure of 13 metallic devices by means of the nuclear techniques of PIXE, RBS and conventional; which were elaborated starting from copper and gold, and they were in the offering of a tarasc personage located in the 'Matamoros' porch in Uruapan, Michoacan, Mexico. (Author)

  18. Self-consistent treatment of nuclear collective motion with an application to the giant-dipole resonance

    International Nuclear Information System (INIS)

    Liran, S.; Technion-Israel Inst. of Tech., Haifa. Dept. of Physics)

    1977-01-01

    This paper extends the recent theory of Liran, Scheefer, Scheid and Greiner on non-adiabatic cranking and nuclear collective motion. In the present work we show the self-consistency conditions for the collective motion, which are indicated by appropriate time-dependent Lagrange multipliers, can be treated explicitly. The energy conservation and the self-consistency condition in the case of one collective degree of freedom are expressed in differential form. This leads to a set of coupled differential equations in time for the many-body wave function, for the collective variable and for the Lagrange multiplier. An iteration procedure similar to that of the previous work is also presented. As an illustrative example, we investigate Brink's single-particle description of the giant-dipole resonance. In this case, the important role played by non-adiabaticity and self-consistency in determining the collective motion is demonstrated and discussed. We also consider the fact that in this example of a fast collective motion, the adiabatic cranking model of Inglis gives the correct mass parameter. (orig.) [de

  19. Management of individual and collective dosimetry at Fessenheim nuclear plant. Evaluation after refueling shutdown

    International Nuclear Information System (INIS)

    Lamarre, D.; Waller, A.

    1980-01-01

    The principle of dosimetry management chosen by Fessenheim nuclear power station was originally consisted of two phases: - an automatic acquisition of individual doses realized by stylodosimeter readers; - a deferred data processing by computer. The whole system has not been used during the shutdown for the first refuelling of unit number one in view of encountered difficulties with perfecting of automatic readers prototype, this last phase has been replaced by a manual acquisition of doses. The dosimetry data processing has two main objects: - supervision of individual dosimetry for people who work in the nuclear power station; - knowledge of doses assigned for each working and equipment. Moreover, a first dosimetric result of the shutdown for refuelling of unit number one, enables to notice the workings which doses are the most important and written in percentage of total doses: regulatory controls: about 19%; - steam generators working: 16%; - working decontamination and making health physics screen (lock chamber) 10% [fr

  20. Establishment of Nuclear Stock Collections for Apple and Pear in Latvia

    Directory of Open Access Journals (Sweden)

    Zuļģe Neda

    2017-06-01

    Full Text Available Apples and pears are among the most important commercial fruit species grown in Latvia. Because of suitability to local climatic conditions, mainly domestic cultivars and cultivars originating in neighbouring countries are grown. The planting material of pome fruits produced and used for establishment of new orchards in Latvia corresponds to the Conformitas Agraria Communitatis standard due to the unavailability of nuclear stock. To establish virus-tested, experimental nuclear stock for apple and pear, one to two years old candidate plants were exposed to thermotherapy at +38 °C for 40 to 70 days. The mother trees and candidate plants before treatment were tested for the presence of the four most widespread pome fruit viruses by RT-PCR. The shoot tips of the heat-treated plants were grafted onto seedling rootstocks and were re-tested for the four viruses by RT-PCR during the next three to five vegetation seasons. Several plants of apple cultivars ‘Dace’, ‘Zarja Alatau’, ‘Rubin’, and ‘Ausma’ remained infected either with Apple chlorotic leaf spot virus, Apple stem growing virus or Apple stem pitting virus after the thermotherapy. Tests on woody indicators were carried out to determine possible presence of graft-transmittable organisms according to EPPO guidelines for the establishment of nuclear stock material for pome fruits.

  1. Nuclear model analysis of excitation functions of proton induced reactions on ⁸⁶Sr, ⁸⁸Sr and natZr: Evaluation of production routes of ⁸⁶Y.

    Science.gov (United States)

    Zaneb, H; Hussain, M; Amjed, N; Qaim, S M

    2015-10-01

    The proton induced nuclear reactions on (86)Sr, (88)Sr and (nat)Zr were investigated for the production of (86)Y. The literature data were compared with the results of nuclear model calculations using the codes ALICE-IPPE, TALYS 1.6 and EMPIRE 3.2. The thick target yields of (86)Y were calculated from the recommended excitation functions. Analysis of radioyttrium impurities was also performed. A comparison of the various production routes showed that for medical applications of (86)Y, the reaction (86)Sr(p,n)(86)Y is the method of choice, which gives efficient yield with minimum impurities. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Excitations in exotic superconductors

    International Nuclear Information System (INIS)

    Hayden, S.

    1999-01-01

    Neutron scattering has played an important role in unravelling the mysteries of superconductivity. Studies of ordinary or conventional superconductors - materials such as aluminium and lead that lose their electrical resistance when cooled below a certain temperature - have focused on vibrations in the lattice structure of the crystal. In these cases magnetic excitations due to the collective motion of electron spins in the crystal are not particularly important and, moreover, are difficult to see. In contrast, magnetic excitations are thought to be important in the newer, exotic or unconventional superconductors such as heavy fermions and cuprates. Two independent groups working at the Institut Laue-Langevin (ILL) in Grenoble, France, and at the Japan Atomic Energy Research Institute (JAERI) in Tokai have recently observed a new magnetic excitation in the superconducting state of the heavy fermion compound uranium-palladium-aluminium, UPd 2 Al 3 , (Phys. Rev. Lett.1998 81 4244; 1998 80 5417). A similar excitation has been observed in yttrium barium copper oxide (YBa 2 Cu 3 O 6.93 ), a high-temperature superconductor. The results may hold clues about the nature of certain types of unconventional superconductivity. In this article the author describes these latest results. (UK)

  3. Mapping the boundaries of the seniority regime and collective motion: Coulomb excitation studies of N = 122 isotones $^{206}$Po and $^{208}$Rn

    CERN Multimedia

    Butler, P; Voulot, D; Rahkila, P J; Darby, I G; Grahn, T; Bree, N C F; Julin, R J; Diriken, J V J; Jenkins, D G; Kroell, T; Huyse, M L

    In regions near magic nuclei, seniority can be regarded as a good quantum number. In the N = 122 isotones above the Z = 82 shell closure relative high-$\\textit{j}\\,$ single-particle proton orbitals dominate the structure and thus levels up to $\\textit{I}$ = 2$\\textit{j}$ - 1 could, in principle, be understood within the seniority scheme. While B(E2) values usually increase within the band with increasing $\\textit{I}$, the seniority scheme can lead to a contrasting result. The present proposal addresses this phenomenon through the measurements of previously unknown B(E2; 0$^{+}\\rightarrow$ 2$^{+}$) values in $^{206}$Po and $^{208}$Rn. The proposed Coulomb excitation measurements of radioactive beams will be carried out at the REX-ISOLDE facility using the MINIBALL $\\gamma$-ray spectrometer.

  4. Relativistic nuclear collisions from the EOS experiment at the Bevalac: collective observables and multifragmentation

    International Nuclear Information System (INIS)

    Insolia, A.

    1996-01-01

    The EOS Collaborations has completed an exclusive study of relativistic heavy ion collisions at the Bevalac using a variety of projectile, target and beam energy combinations. We report here results on directed sidewards flow in Au+Au between 0.25 AGeV and 1.2 AGeV, using a standard in-plane transverse momentum analysis. We also report on projectile fragmentation of Au in C at 1 AGeV. An analysis of fluctuations and critical exponents for small systems seems to support the idea that the multifragmentation regime is associated with a liquid gas phase transition in nuclear matter. (authors)

  5. Physics with radioactive nuclear beams

    International Nuclear Information System (INIS)

    Boyd, R.N.

    1995-01-01

    Recently developed facilities allow a wide range of new investigations of the reactions and properties of short-lived nuclei. These studies may help to solve puzzles of nuclear structure and the Big Bang. The purpose of nuclear physics is to measure properties of specific nuclides and infer from them global properties common to all nuclides, for example, is to understand nuclear sizes and matter distributions in terms of basic nuclear forces. Another is to understand the variation throughout the periodic table of the dominant quantum states, which are known as the open-quotes nuclear shell model close quotes states and are characterized, much as are atomic states, by a principal quantum number and by orbital and total angular momentum quantum numbers. In turn other nuclear phenomena, such as the collective excitations known as giant resonances, can be understood in terms of the shell-model configurations and basic nuclear parameters. Radioactive nuclear beam studies of reactions of short-lived nuclides have already yielded results with important ramifications in both nuclear physics and astrophysics. Nuclear physicists expect unstable nuclides to exhibit unusual structures or features that may test their understanding of known nuclear phenomena at extreme conditions, and perhaps even to reveal previously unknown nuclear phenomena, Astrophysicists, for their part, have known for several decades that processes in both Big Bang nucleosynthesis and stellar nucleosynthesis involve short-lived nuclides. Indeed, the original motivation for developing radioactive nuclear beams was astrophysical. (author). 25 refs., 7 figs

  6. Physics with radioactive nuclear beams

    International Nuclear Information System (INIS)

    Boyd, R.N.; Tanihata, I.

    1992-01-01

    Recently developed facilities allow a wide range of new investigations of the reactions and properties of short-lived nuclei. These studies may help to solve puzzles of nuclear structure and the Big Bang. The purpose of nuclear physics is to measure properties of specific nuclides and infer from them global properties common to all nuclides. One goal, for example, is to understand nuclear sizes and matter distributions in terms of basic nuclear forces. Another is to understand the variation throughout the periodic table of the dominant quantum states, which are known as the open-quotes nuclear shell modelclose quotes states and are characterized, much as are atomic states, by a principal quantum number and by orbital and total angular momentum quantum numbers. In turn other nuclear phenomena, such as the collective excitations known as giant resonances, can be understood in terms of the shell-model configurations and basic nuclear parameters. Radioactive nuclear beam studies of reactions of short-lived nuclides have already yielded results with important ramifications in both nuclear physics and astrophysics. Nuclear physicists expect unstable nuclides to exhibit unusual structures or features that may test their understanding of known nuclear phenomena at extreme conditions, and perhaps even to reveal previously unknown nuclear phenomena, Astrophysicists, for their part, have known for several decades that processes in both Big Bang nucleosynthesis and stellar nucleosynthesis involve short-lived nuclides. Indeed, the original motivation for developing radioactive nuclear beams was astrophysical. 25 refs., 7 figs

  7. Gordon Conference on Nuclear Research

    International Nuclear Information System (INIS)

    Austin, S.M.

    1983-09-01

    Session topics were: quarks and nuclear physics; anomalons and anti-protons; the independent particle structure of nuclei; relativistic descriptions of nuclear structure and scattering; nuclear structure at high excitation; advances in nuclear astrophysics; properties of nuclear material; the earliest moments of the universe; and pions and spin excitations in nuclei

  8. Study of the nuclear structure far from stability: Coulomb excitation of neutron-rich Rb isotopes around N=60; Production of nuclear spin polarized beams using the tilted foils technique

    International Nuclear Information System (INIS)

    Sotty, C.

    2013-01-01

    The underlying structure in the region A ∼ 100, N ∼ 60 has been under intensive and extensive investigation, mainly by β-decay and γ-ray spectroscopy from fission processes. Around N ∼ 60, by adding just few neutrons, protons a rapid shape change occurs from spherical-like to well deformed g.s. shape. Shape coexistence has been observed in the Sr and Zr nuclei, and is expected to take place in the whole region. The mechanisms involved in the appearance of the deformation is not well understood. The interplay between down-sloping and up-sloping neutron Nilsson orbital is evoked as one of the main reasons for the sudden shape change. However, a clear identification of the active proton and neutron orbitals was still on-going. For that purpose, the neutron rich 93;95;97;99 Rb isotopes have been studied by Coulomb excitation at CERN (ISOLDE) using the REX-ISOLDE post-accelerator and the MINIBALL setup. The completely unknown structures of 97;99 Rb have been populated and observed. Prompt γ-ray coincidences of low-lying states have been observed and time-correlated in order to build level schemes. The associated transition strengths have been extracted with the GOSIA code. The observed matrix elements of the electromagnetic operator constituted new inputs of further theoretical calculations giving new insight on the involved orbitals. The sensitivity of such experiment can be increased using nuclear spin polarized radioactive ion beam. For that purpose the Tilted Foils Technique (TFT) of polarization has been investigated at CERN. This technique consists to spin polarize the ion beam, passing through thin foils tilted at an oblique angle with respect to the beam direction. The initially obtained atomic polarization is transferred to the nucleus by hyperfine interaction. This technique does not depend on the chemical nature of the element. Short lived nuclei can be polarized in-flight without any need to be stopped in a catcher. It opens up the possibility to

  9. Collective occupational dose for nuclear reactors of the 2., 3. and 4. generation

    International Nuclear Information System (INIS)

    Guidez, J.; Saturnin, A.

    2016-01-01

    In France during reactor operation the individual occupational doses are collected and recorded according to the law. When you sum up all the individual doses you get the yearly collective dose expressed in Man.Sv/year. This piece of information can be used to make comparisons between various types of reactors and between reactors of the same type. The results show a steady decrease of the collective dose for all types of reactors over the time except for CANDU reactors for which a slight increase of the dose has appeared since the years 1996-1998. The decrease is due to the continuous improvement of reactor operating and to changes in the reactor design. There is also a constant gap over time between the collective dose for a BWR reactor (1.12 Man.Sv/y) and a PWR reactor 0.60 Man.Sv/y), this gap is certainly due to N 16 nuclide that is created in the primary circuit and transported to turbines in the case of a BWR reactor. For sodium-cooled fast reactors (RNR-Na) the collective dose is below 0.40 Man.Sv/y except for the BN-600 reactor. (A.C.)

  10. Effective interactions and elementary excitations in quantum liquids

    International Nuclear Information System (INIS)

    Pines, D.

    1986-01-01

    The effective interactions which provide a wavevector and frequency dependent restoring force for collective modes in quantum liquids are derived for the helium liquids by means of physical arguments and sum rule and continuity considerations. A simple model is used to take into account mode-mode coupling between collective and multiparticle excitations, and the results for the zero-temperature liquid 4 He phonon-maxon-roton spectrum are shown to compare favorably with experiment and with microscopic calculation. The role played by spin-dependent backflow in liquid 3 He is analyzed, and a physical interpretation of its variation with density and spin-polarization is presented. A progress report is given on recent work on effective interactions and elementary excitations in nuclear matter, with particular attention to features encountered in the latter system which have no counterparts in the helium liquids

  11. Direct interaction in nuclear reactions: a theory

    International Nuclear Information System (INIS)

    Dominicis, C.T. de

    1959-01-01

    General treatment of the foundations of direct interaction in nuclear reactions; representation of the instantaneous elastic scattering amplitude by the scattering amplitude due to a complex potential; expansion of the instantaneous inelastic scattering amplitude and discussion of the 1. Bohr approximation (distorted waves) contribution to individual and collective states of excitation. (author) [fr

  12. A quantal transport theory for nuclear collective motion: the merits of a locally harmonic approximation

    International Nuclear Information System (INIS)

    Hofmann, H.

    1997-01-01

    A transport theory is developed for collective motion of systems such as an atomic nucleus, which may be considered as a typical representative of a self-bound micro-system. Albeit for pragmatic reasons, collective variables are introduced as shape parameters, self-consistency with respect to the nucleonic degrees of freedom has been implemented at various important stages. This feature leads to subsidiary conditions which are obeyed locally for both the average motion as well as for the quantized Hamiltonian constructed through a Bohm-Pines procedure. Furthermore, self-consistency governs the definition of the transport coefficients appearing in the equations for collective motion. The latter is associated to the time evolution of the density in collective phase space, for which the concept of the Wigner function is employed. Global motion is described by propagating the system in successive time laps which are macroscopically small, but microscopically large. This enables one to exploit linearization procedures and to take advantage of the benefits of linear response theory. A microscopic damping mechanism is introduced by dressing the energies of the independent particle model by complex self-energies, the parameters of which are determined from optical model considerations. Numerical evaluations of transport coefficients are described and tested for the case of fission in the light of recent experimental findings. The theory allows one to extend both Kramers' picture of this process as well as his equation for the density distribution into the quantum regime. (orig.)

  13. Nuclear dissipation as damping of collective motion in the time-dependent RPA and extensions of it

    International Nuclear Information System (INIS)

    Yannouleas, C.P.

    1982-07-01

    We have formulated a nonperturbative, microscopic dissipative process in the limit of an infinite mean free path which does not require any statistical assumptions. It attributes the damping of the collective motion to real transitions from the collective state to degenerate, more complicated nucelar states. The dissipation is described through wave packets which solve an approximate Schroedinger equation within extended subspaces, larger than the original subspace of the undamped motion. When the simple RPA is used, this process associates the dissipation with the escape width for direct particle emission. When the Second RPA is used, it associates the dissipation with the spreading width for transitions to the 2p-2h components of the nuclear compound states. The energy loss rate for sharp n-phonon initial states is proportional to the total collective energy. The classical dissipation, however, is obtained for coherent, multiphonon, initial packets which describe the damping of the mean field oscillations, and allow a theoretical connection with the Vibrating Potential Model, and thereby with models of one-body dissipation. The present model contrasts with linear response theories. Canonical coordinates for the collective degree of freedom are explicitly introduced. This allows the construction of a nonlinear frictional Hamiltonian which provides a connection with quantal friction. The dissipation process developed here is properly reversible rather than irreversible, in the sense that it is described by an approximate Schroedinger equation which honors time reversibility, rather than by a coarse grained master equation which violates it. Thus, the present theory contrasts with transport theories

  14. Nuclear medicine at Camaguey, 1995-1999. Frequency of examinations and collective effective dose to the population

    International Nuclear Information System (INIS)

    Barreras, C. Aldo; Brigido, F. Osvaldo; Naranjo, L. Angela; Lasserra, S. Oscar; Hernandez, G. Jose

    2001-01-01

    A study of the frequency of examinations for diagnosis in the territory of Camaguey-Ciego de Avila, Cuba, was made from the accumulated statistic in the period of 1995-1999 with the objective to obtain data to estimate the collective dose distributed to the population of this territory. It was determined that the annual frequency average of examinations was of 3,82 by each 1000 inhabitants. The obtained data allowed to evaluate the contribution of the different examinations from the collective dose, corresponding to the gamma radiographs of thyroid and pick up 43,73 and 43,36%, respectively, of the 54,43 Sv.man distributed to the population like annual. In this work the annual behavior of the collective dose for the studied period and its behavior in relation to the frequency of made examinations are analyzed. The smaller annual collective dose corresponded to 1996 with 39,05 Sv.man, while the greater value corresponded to 1999 with 66,67 Sv.man. The additional total damage for the studied period is considered: there would be 19,87 additional cases like result of 21073 nuclear medicine examinations, of which 13,6 correspond to mortal cancer. The obtained results are compared with the results reported for other countries

  15. Non-unitary boson mapping and its application to nuclear collective motions

    International Nuclear Information System (INIS)

    Takada, Kenjiro

    2001-01-01

    First, the general theory of boson mapping for even-number many-fermion systems is surveyed. In order to overcome the confusion concerning the so-called unphysical or spurious states in the boson mapping, the correct concept of the unphysical states is precisely given in a clear-cut way. Next, a method to apply the boson mapping to a truncated many-fermion Hilbert space consisting of collective phonons is proposed, by putting special emphasis on the Dyson-type non-unitary boson mapping. On the basis of this method, it becomes possible for the first time to apply the Dyson-type boson mapping to analyses of collective motions in realistic nuclei. This method is also extended to be applicable to odd-number-fermion systems. As known well, the Dyson-type boson mapping is a non-unitary transformation and it gives a non-Hermitian boson Hamiltonian. It is not easy (but not impossible) to solve the eigenstates of the non-Hermitian Hamiltonian. A Hermitian treatment of this non-Hermitian eigenvalue problem is discussed and it is shown that this treatment is a very good approximation. using this Hermitian treatment, we can obtain the normal-ordered Holstein-Primakoff-type boson expansion in the multi-collective-phonon subspace. Thereby the convergence of the boson expansion can be tested. Some examples of application of the Dyson-type non-unitary boson mapping to simplified models and realistic nuclei are also shown, and we can see that it is quite useful for analysis of the collective motions in realistic nuclei. In contrast to the above-mentioned ordinary type of boson mapping, which may be called a a 'static' boson mapping, the Dyson-type non-unitary self-consistent-collective-coordinate method is discussed. The latter is, so to speak, a 'dynamical' boson mapping, which is a dynamical extension of the ordinary boson mapping to be capable to include the coupling effects from the non-collective degrees of freedom self-consistently.Thus all of the Dyson-type non-unitary boson

  16. Hidden multiparticle excitation in weakly interacting Bose-Einstein Condensate

    OpenAIRE

    Watabe, Shohei

    2017-01-01

    We investigate multiparticle excitation effect on a collective density excitation as well as a single-particle excitation in a weakly interacting Bose--Einstein condensate (BEC). We find that although the weakly interacting BEC offers weak multiparticle excitation spectrum at low temperatures, this multiparticle excitation effect may not remain hidden, but emerges as bimodality in the density response function through the single-particle excitation. Identification of spectra in the BEC betwee...

  17. The time dependent Hartree-Fock-theory for collective nuclear motions

    International Nuclear Information System (INIS)

    Goeke, K.

    1976-11-01

    The time-dependent Hartree-Fock theory (TDHF) approximately solves the Schroedinger equation by a variational method in the space of the time-dependent Slater determinants. As the TDHF wave function, similar to the exact solution has the property of being determined completely for all times by the nucleon-nucleon interaction and by assuming initial conditions. TDHF is expected to describe collective motion of nuclei with large amplitudes, too. The subject of this paper is to formulate the TDHF theory and its adiabatic limiting case (ATDHF) suited for setting up a collective Schroedinger equation, to investigate the relations with other theories, and to show the applicability for solving practical problems. (orig./WL) [de

  18. A guide to archival collections relating to radioactive fallout from nuclear weapon testing

    International Nuclear Information System (INIS)

    1989-10-01

    This guide has been prepared by professional historians who have a working knowledge of many of the record collections, included in the following pages. In describing materials, they have tried to include enough information so that persons unfamiliar with the complexities of large record systems will be able to determine the nature of the information in, and the quality of, each record collection. The guide is organized alphabetically by the means of the record repositories, not by the organizations which have custody of the records. It should be noted that arrangement by location does not reveal at a single glance all of the materials that may have originated in a specific laboratory, research center, or government agency. For example, records originated in one of the Atomic Energy Commission's national laboratories may, in some cases, be listed under the Federal Records Centers to which they have been retired. Thus, this guide includes an index of agencies originating documents and pages listing those agencies

  19. Selective Coherent Excitation of Charged Density Waves

    NARCIS (Netherlands)

    Tsvetkov, A.A.; Sagar, D.M.; Loosdrecht, P.H.M. van; Marel, D. van der

    2003-01-01

    Real time femtosecond pump-probe spectroscopy is used to study collective and single particle excitations in the charge density wave state of the quasi-1D metal, blue bronze. Along with the previously observed collective amplitudon excitation, the spectra show several additional coherent features.

  20. Collection, validation, and description of data for the Oak Ridge nuclear industry mortality study

    International Nuclear Information System (INIS)

    Watkins, J.; Reagan, J.; Cragle, D.; West, C.; Tankersley, W.; Frome, E.; Watson, J.

    1992-01-01

    In response to the continuing controversy over the long-term health effects of protracted occupational exposure to low levels of ionizing radiation, a mortality study was initiated pooling data for all workers hired before December 31, 1982, and employed for at least 30 days by one of the three DOE facilities in Oak Ridge, Tennessee. Topics of discussion will include issues involving the collection and validation of this large, complex data set and characteristics of demographic and exposure data for the study cohort

  1. Analysis of Ling'ao nuclear power station unit 1 exciter No.11 bearing white metal damage and its operating temperature abnormally high

    International Nuclear Information System (INIS)

    Jia Kaili

    2005-01-01

    On the base of analyzing the type of exciter No.11 bearing white metal damage, the root cause and its solution are found. No damage was found on bearing white metal in the later time. On the base of analyzing the structure of the generator end bracket, it is pointed out that when the generator frame is full of pressed gas, the end bracket will deform, that result in the load on No.11 bearing increase, as a result causes the bearing temperature high. A proposal to this problem is presented. (author)

  2. Nuclear excitations and reaction mechanisms. Progress report, 1 November 1979-30 September 1980. [Dept. of Physics, Brown Univ. , Providence, Rhode Island

    Energy Technology Data Exchange (ETDEWEB)

    1980-10-01

    Among the topics investigated were the following: photon scattering and consistency condition between seagull quadrupole terms and the absorption sum rule; Raman scattering to negative-parity states; nonlocal terms due to exchange and retardation effects in charge-transfer reactions; consistency and meaning of various approximate channel coupling array equations; derivation of equations used in empirical nuclear reaction analyses; multicluster, n-particle scattering theory; converged molecular bound state calculations; consistency of approximate channel coupling array equations; derivations of equations used in empirical nuclear reaction analyses; and WKB-type approximation in angular momenta for central potentials. References to publications are given.

  3. Comparative analysis of collective doses received since 1976 at the Ardennes nuclear power plant

    International Nuclear Information System (INIS)

    Aye, Louis

    1980-01-01

    The analysis of the collective doses at the Centrale nucleaire des Ardennes povides valuable data about the origin of exposures in P.W.R. reactors and their evolution regarding the increase of activity of the circuits after more than 10 years of operation. The investigations led for most of the works since 1976 reveals that, in some cases, the use of sophisticated implements combined with modifications of equipments and procedures may bring appreciable savings on doses during normal operation as well as maintenance and refuelings shut-down. However, the study gives the 'reasonably achievable' limits than can be aimed in a plant on operation, the doses resulting mainly from problems that should be taken into account at design [fr

  4. Collect, analyze and data base for building up the investment reports of Center for Nuclear Science and Technology construction project

    International Nuclear Information System (INIS)

    Pham Quang Minh; Tran Chi Thanh; Cao Dinh Thanh; Mai Dinh Trung; Hoang Sy Than; Nguyen Nhi Dien; Trinh Van Giap; Le Ba Thuan; Vu Tien Ha

    2014-01-01

    Following the Contract No.19/HD/NVCB dated July 10, 2013 signed by the President of Vietnam Atomic Energy Institute (VINATOM), an additional ministerial Project was approval by the Decision No. 526/QD-VNLNT dated July 8, 2013 by the VINATOM President in order to implement an important task for VINATOM. This project was implemented by the Institute for Nuclear Science and Technology (INST) in Hanoi as management organization and VINATOM as the owner of project results. Main objectives of this Project are to support national budget for implementing to collected the general report from previous projects which are relevant to CNEST and new research reactor, IAEA guidance documents, documents provided by ROSATOM in seminars in 2010, 2012 and 2013, report from expert visits of Ministry of Science and Technology and completed the general report about the construction project of CNEST. (author)

  5. The collection, storage and use of equipment performance data for the safety and reliability assessment of nuclear power plants

    International Nuclear Information System (INIS)

    Fothergill, C.D.H.

    1975-01-01

    It has been characteristic of the Nuclear Industry that it should grow up in an atmosphere where reliability and operational safety considerations have been of vital importance. Consequently all aspects of Nuclear Power Reactor design, construction and operation (in the U.K.A.E.A.) are subjected to rigorous reliability assessments, beginning with the automatic protective devices and the safety shut-down systems. This has resulted in the setting up of large and small private data stores to support this upsurgence of Safety and Reliability assessment work. Unfortunately, much of the information being stored and published falls short of the minimum requirements of Safety Assessors and Reliability Analysts who need to make use of it. That there is still an urgent need for more work to be done in the Reliability Data field is universally acknowledged. The characteristics which make up good quality reliability data must be defined and achievable minimum standards must be set for its identification, collection, storage and retrieval. To this end the United Kingdom Atomic Energy Authority have set up the Systems Reliability Service Data Bank. This includes a computerized storage facility comprised of two principal data stores: (i) Reliability Data Store, (ii) Event Data Store. The figures available in the Reliability Data Store range from those relating to the lifetimes of minute components to those obtained from the assessment of whole plants and complete assemblies. These data have been accumulated from many reliable sources both inside and outside the Nuclear Industry, including the transfer of 'live' data generated from the results of reliability surveillance exercises associated with Event Data collection. Computer techniques developed specifically for the Reliability Data Store enable further 'processing' of these data to be carried out. The Event Data Store consists of three discrete computerized data stores, each one providing the necessary storage, retrieval and

  6. Data collection, validation, and description for the Oak Ridge nuclear facilities mortality study

    International Nuclear Information System (INIS)

    Watkins, J.P.; Reagan, J.L.; Cragle, D.L.; West, C.M.; Tankersley, W.G.; Crawford-Brown, D.J.

    1995-01-01

    To investigate the long-term health effects of protracted occupational exposure to low levels of ionizing radiation, a mortality study was initiated by pooling data for 118,588 workers hired between 1943 and 1982, at three Department of Energy (DOE) facilities in Oak Ridge, Tennessee, with follow-up through 1984. Topics for this discussion will include issues involving the collection and validation of data for individuals in the study cohort, and characteristics of their demographic and radiation exposure data. Since the data were compiled between the late 1960s and the present under the direction of several principal investigators, it was essential to verify data precision and to understand how exposure data were generated prior to beginning any analysis. A stratified random sample of workers in the cohort was chosen for verification of their computerized data as it appeared in the database. Original source documents were reviewed to verify demographic data, as well as internal and external radiation exposure data. Extensive effort was expended to document the personal radiation monitoring policies and types of dosimeters used at each facility over the 42 years included in the study. Characteristics of internal and external exposure data by facility and year were examined by graphical methods with the intent of combining these monitoring data over time and across facilities

  7. New measurements of excitation functions of {sup 186}W(p,x) nuclear reactions up to 65 MeV. Production of a {sup 178}W/{sup 178m}Ta generator

    Energy Technology Data Exchange (ETDEWEB)

    Tárkányi, F.; Ditrói, F.; Takács, S. [Institute of Nuclear Research (ATOMKI), Debrecen (Hungary); Hermanne, A., E-mail: aherman@vub.ac.be [Cyclotron Department, Vrije Universiteit Brussel, (VUB), Brussels (Belgium)

    2017-01-15

    New experimental excitation functions for proton induced reactions on {sup nat}W are presented in the 32–65 MeV energy range. The cross-sections for {sup nat}W(p,xn){sup 186,184m,184g,183,} {sup 182m,182g,181}Re, {sup nat}W(p,x){sup 178}W{sup ,} {sup nat}W(p,x){sup 183,182,} {sup 180m,} {sup 177,176,175}Ta, {sup 175}Hf and {sup 177}Lu were measured via an activation method by using a stacked-foil irradiation technique and high resolution gamma-ray spectroscopy. The results were compared with predicted values obtained with the nuclear reaction code TALYS (results taken from the TENDL 2014 and TENDL 2015 on-line libraries). Production routes of the medically relevant radionuclides {sup 186}Re, the {sup 178}W → {sup 178}Ta generator and {sup 181}W are discussed.

  8. Anomalous tunneling of collective excitations and effects of superflow in the polar phase of a spin-1 spinor Bose-Einstein condensate

    International Nuclear Information System (INIS)

    Watabe, Shohei; Ohashi, Yoji; Kato, Yusuke

    2011-01-01

    We investigate tunneling properties of collective modes in the polar phase of a spin-1 spinor Bose-Einstein condensate (BEC). This spinor BEC state has two kinds of gapless modes (i.e., Bogoliubov and spin-wave). Within the framework of mean-field theory at T=0, we show that these Goldstone modes exhibit perfect transmission in the low-energy limit. Their anomalous tunneling behavior still holds in the presence of superflow, except in the critical current state. In the critical current state, while the tunneling of Bogoliubov mode is accompanied by finite reflection, the spin wave still exhibits perfect transmission, unless the strengths of spin-dependent and spin-independent interactions take the same value. We discuss the relation between perfect transmission of a spin wave and underlying superfluidity through a comparison of wave functions of the spin wave and the condensate.

  9. Anomalous tunneling of collective excitations and effects of superflow in the polar phase of a spin-1 spinor Bose-Einstein condensate

    Energy Technology Data Exchange (ETDEWEB)

    Watabe, Shohei; Ohashi, Yoji [Department of Physics, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan); CREST (JST), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Kato, Yusuke [Department of Basic Science, University of Tokyo, Tokyo 153-8902 (Japan)

    2011-07-15

    We investigate tunneling properties of collective modes in the polar phase of a spin-1 spinor Bose-Einstein condensate (BEC). This spinor BEC state has two kinds of gapless modes (i.e., Bogoliubov and spin-wave). Within the framework of mean-field theory at T=0, we show that these Goldstone modes exhibit perfect transmission in the low-energy limit. Their anomalous tunneling behavior still holds in the presence of superflow, except in the critical current state. In the critical current state, while the tunneling of Bogoliubov mode is accompanied by finite reflection, the spin wave still exhibits perfect transmission, unless the strengths of spin-dependent and spin-independent interactions take the same value. We discuss the relation between perfect transmission of a spin wave and underlying superfluidity through a comparison of wave functions of the spin wave and the condensate.

  10. Disturbances of nuclear maturation in BCB positive oocytes collected from peri-pubertal gilts.

    Science.gov (United States)

    Pawlak, P; Pers-Kamczyc, E; Renska, N; Kubickova, S; Lechniak, D

    2011-03-15

    The developmental competence (quality) of oocytes is affected by several factors linked to their intrinsic properties and also to growth and maturation environment. Donor puberty and chromosomal complement are one of the main factors influencing oocyte quality. A high rate of porcine oocytes matured in vitro is chromosomally imbalanced. Moreover, there is no published data on chromosomal aberrations in oocytes selected by the brilliant cresyl blue (BCB) test. Therefore, the aim of this study was to analyze whether BCB positive (BCB+) oocytes derived from ovaries of peripubertal gilts (prepubertal NCL and cyclic CL) differ with respect to the incidence of numerical chromosome aberrations. COCs collected from NCL and CL ovaries were selected by the BCB test. Only BCB+ oocytes were matured in vitro and subjected to FISH analysis using molecular probes for chromosome pairs 1 and 10. The rate of BCB+ oocytes was similar for both groups of ovaries (NCL 80%, CL 92%). Altogether 554 oocytes were fixed and 471 oocytes at the MII stage were analyzed cytogenetically. Diploid (2MII) and aneuploid oocytes were detected. The contribution of MII oocytes was similar for NCL (85%) and CL (90%) group. Chromosomally aberrant BCB+ oocytes accounted for 18.0% and ranged from 13.7% for CL and 22.2% for NCL ovaries. Diploidy was a predominant anomaly observed (11.2%) with a significantly higher frequency in BCB+ oocytes of pre-pubertal (16.7%) than cyclic gilts (5.6%, P < 0.05). Aneuploid oocytes occurred with similar rate in NCL (6.7%) and CL (8.5%) females. The majority of aneuploid spreads (72.2%; P < 0.01) concerned the chromosome pair 10. The overall rate of disomy (56%) and nullisomy (44.4%) was similar. We have shown that donor puberty affects the incidence of chromosomal abnormalities in porcine oocytes matured in vitro. Significantly more diploid oocytes was derived from prepubertal ovaries, whereas the frequency of aneuploidy was similar in NCL and CL gilts. Copyright © 2011

  11. On the resonant coherent excitation of relativistic heavy ions

    International Nuclear Information System (INIS)

    Pivovarov, Y.L.; Geissel, H.; Filimonov, Yu.M.; Krivosheev, O.E.; Scheidenberger, C.

    1995-07-01

    New accelerator facilities open up an interesting new field of experiments on basic channeling as well as on atomic and nuclear resonant coherent exitation (RCE) of heavy ions penetrating through aligned crystals at relativistic energies. Results of computer simulations are presented to characterize the resonant coherent excitation of atomic levels of relativistic hydrogen-like heavy ions. Nuclear resonant coherent excitation reveals interesting different characteristics compared to the corresponding atomic excitation inside crystals. An important result of our model calculations is that poorly-channeled ions have a higher nuclear excitation probability than well-channeled ions. (orig.)

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

    CERN Document Server

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

    2001-01-01

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

  13. Collection and classification of human error and human reliability data from Indian nuclear power plants for use in PSA

    International Nuclear Information System (INIS)

    Subramaniam, K.; Saraf, R.K.; Sanyasi Rao, V.V.S.; Venkat Raj, V.; Venkatraman, R.

    2000-01-01

    Complex systems such as NPPs involve a large number of Human Interactions (HIs) in every phase of plant operations. Human Reliability Analysis (HRA) in the context of a PSA, attempts to model the HIs and evaluate/predict their impact on safety and reliability using human error/human reliability data. A large number of HRA techniques have been developed for modelling and integrating HIs into PSA but there is a significant lack of HAR data. In the face of insufficient data, human reliability analysts have had to resort to expert judgement methods in order to extend the insufficient data sets. In this situation, the generation of data from plant operating experience assumes importance. The development of a HRA data bank for Indian nuclear power plants was therefore initiated as part of the programme of work on HRA. Later, with the establishment of the coordinated research programme (CRP) on collection of human reliability data and use in PSA by IAEA in 1994-95, the development was carried out under the aegis of the IAEA research contract No. 8239/RB. The work described in this report covers the activities of development of a data taxonomy and a human error reporting form (HERF) based on it, data structuring, review and analysis of plant event reports, collection of data on human errors, analysis of the data and calculation of human error probabilities (HEPs). Analysis of plant operating experience does yield a good amount of qualitative data but obtaining quantitative data on human reliability in the form of HEPs is seen to be more difficult. The difficulties have been highlighted and some ways to bring about improvements in the data situation have been discussed. The implementation of a data system for HRA is described and useful features that can be incorporated in future systems are also discussed. (author)

  14. Analysis of dust samples collected from spent nuclear fuel interim storage containers at Hope Creek, Delaware, and Diablo Canyon, California

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, Charles R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Enos, David George [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-07-01

    Potentially corrosive environments may form on the surface of spent nuclear fuel dry storage canisters by deliquescence of deposited dusts. To assess this, samples of dust were collected from in-service dry storage canisters at two near-marine sites, the Hope Creek and Diablo Canyon storage installations, and have been characterized with respect to mineralogy, chemistry, and texture. At both sites, terrestrially-derived silicate minerals, including quartz, feldspars, micas, and clays, comprise the largest fraction of the dust. Also significant at both sites were particles of iron and iron-chromium metal and oxides generated by the manufacturing process. Soluble salt phases were minor component of the Hope Creek dusts, and were compositionally similar to inland salt aerosols, rich in calcium, sulfate, and nitrate. At Diablo Canyon, however, sea-salt aerosols, occurring as aggregates of NaCl and Mg-sulfate, were a major component of the dust samples. The seasalt aerosols commonly occurred as hollow spheres, which may have formed by evaporation of suspended aerosol seawater droplets, possibly while rising through the heated annulus between the canister and the overpack. The differences in salt composition and abundance for the two sites are attributed to differences in proximity to the open ocean and wave action. The Diablo Canyon facility is on the shores of the Pacific Ocean, while the Hope Creek facility is on the shores of the Delaware River, several miles from the open ocean.

  15. Excitations in Topological Superfluids and Superconductors

    Science.gov (United States)

    Wu, Hao

    In this thesis I present the theoretical work on Fermionic surface states, and %the bulk Bosonic collective excitations in topological superfluids and superconductors. Broken symmetries %Bulk-edge correspondence in topological condensed matter systems have implications for the spectrum of Fermionic excitations confined on surfaces or topological defects. (Abstract shortened by ProQuest.).

  16. Analysis of Dust Samples Collected from an In-Service Interim Storage System at the Maine Yankee Nuclear Site.

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, Charles R.; Enos, David

    2016-10-01

    In July, 2016, the Electric Power Research Institute and industry partners performed a field test at the Maine Yankee Nuclear Site, located near Wiscasset, Maine. The primary goal of the field test was to evaluate the use of robots in surveying the surface of an in-service interim storage canister within an overpack; however, as part of the demonstration, dust and soluble salt samples were collected from horizontal surfaces within the interim storage system. The storage system is a vertical system made by NAC International, consisting of a steel-lined concrete overpack containing a 304 stainless steel (SS) welded storage canister. The canister did not contain spent fuel but rather greater-than-class-C waste, which did not generate significant heat, limiting airflow through the storage system. The surfaces that were sampled for deposits included the top of the shield plug, the side of the canister, and a shelf at the bottom of the overpack, just below the level of the pillar on which the canister sits. The samples were sent to Sandia National Laboratories for analysis. This report summarizes the results of those analyses. Because the primary goal of the field test was to evaluate the use of robots in surveying the surface of the canister within the overpack, collection of dust samples was carried out in a qualitative fashion, using paper filters and sponges as the sampling media. The sampling focused mostly on determining the composition of soluble salts present in the dust. It was anticipated that a wet substrate would more effectively extract soluble salts from the surface that was sampled, so both the sponges and the filter paper were wetted prior to being applied to the surface of the metal. Sampling was accomplished by simply pressing the damp substrate against the metal surface for two minutes, and then removing it. It is unlikely that the sampling method quantitatively collected dust or salts from the metal surface; however, both substrates did extract a

  17. Evaluation of the excitation function of the 238U(n,2n)237U reaction for neutron energies from threshold to 19 MeV

    International Nuclear Information System (INIS)

    Kornilov, N.V.; Vinogradov, V.N.; Gay, E.V.; Rabotnov, N.S.; Salnikov, O.A.; Raics, P.; Daroczy, S.; Nagy, S.; Csikai, J.

    1983-01-01

    Experimental results for the 238 U(n,2n) reaction were collected from the literature and evaluated. The normalisation of the measured cross sections was carried out using recent values for the cross sections of standard monitor reactions as well as new nuclear decay data. The evaluated excitation function was then obtained by the Pade-approximation. (Auth.)

  18. Define and Quantify the Physics of Air Flow, Pressure Drop and Aerosol Collection in Nuclear Grade HEPA Filters

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Murray E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-23

    Objective: Develop a set of peer-review and verified analytical methods to adjust HEPA filter performance to different flow rates, temperatures and altitudes. Experimental testing will measure HEPA filter flow rate, pressure drop and efficiency to verify the analytical approach. Nuclear facilities utilize HEPA (High Efficiency Particulate Air) filters to purify air flow for workspace ventilation. However, the ASME AG-1 technical standard (Code on Nuclear Air and Gas Treatment) does not adequately describe air flow measurement units for HEPA filter systems. Specifically, the AG-1 standard does not differentiate between volumetric air flow in ACFM (actual cubic feet per minute)compared to mass flow measured in SCFM (standard cubic feet per minute). More importantly, the AG-1 standard has an overall deficiency for using HEPA filter devices at different air flow rates, temperatures, and altitudes. Technical Approach: The collection efficiency and pressure drops of 18 different HEPA filters will be measured over a range of flow rates, temperatures and altitudes. The experimental results will be compared to analytical scoping calculations. Three manufacturers have allocated six HEPA filters each for this effort. The 18 filters will be tested at two different flow rates, two different temperatures and two different altitudes. The 36 total tests will be conducted at two different facilities: the ATI Test facilities (Baltimore MD) and the Los Alamos National Laboratory (Los Alamos NM). The Radiation Protection RP-SVS group at Los Alamos has an aerosol wind tunnel that was originally designed to evaluate small air samplers. In 2010, modifications were started to convert the wind tunnel for HEPA filter testing. (Extensive changes were necessary for the required aerosol generators, HEPA test fixtures, temperature control devices and measurement capabilities.) To this date, none of these modification activities have been funded through a specific DOE or NNSA program. This is

  19. Excited charmed mesons

    International Nuclear Information System (INIS)

    Butler, J.N.; Shukla, S.

    1995-05-01

    The experimental status of excited charmed mesons is reviewed and is compared to theoretical expectations. Six states have been observed and their properties are consistent with those predicted for excited charmed states with orbital angular momentum equal to one

  20. Isotope separation using vibrationally excited molecules

    International Nuclear Information System (INIS)

    Woodroffe, J.A.; Keck, J.C.

    1979-01-01

    Vibrational excitation of molecules having components of a selected isotope type is used to produce a conversion from vibrational to translational excitation of the molecules by collision with the molecules of a heavy carrier gas. The resulting difference in translaton between the molecules of the selected isotope type and all other molecules of the same compound permits their separate collection. When applied to uranium enrichment, a subsonic cryogenic flow of molecules of uranium hexafluoride in combination with an argon carrier gas is directed through a cooled chamber that is illuminated by laser radiaton tuned to vibrationally excite the uranium hexafluoride molecules of a specific uranium isotope. The excited molecules collide with carrier gas molecules, causing a conversion of the excitation energy into a translation of the excited molecule, which results in a higher thermal energy or diffusivity than that of the other uranium hexafluoride molecules. The flowing molecules including the excited molecules directly enter a set of cryogenically cooled channels. The higher thermal velocity of the excited molecules increases the probability of their striking a collector surface. The molecules which strike this surface immediately condense. After a predetermined thickness of molecules is collected on the surface, the flow of uranium hexafluoride is interrupted and the chamber heated to the point of vaporization of the collected hexafluoride, permitting its removal. (LL)

  1. Analysis of communication contents and the associated crew performance data collected from abnormal operating conditions of nuclear power plants

    International Nuclear Information System (INIS)

    Park, Jin Kyun; Kim, Seung Hwan; Kim, Man Cheol

    2010-11-01

    There would be no objection about the fact that, in the case of human operators working in a large process control system, the consequence of inappropriate communications would be more sensitive because they have to carry out many kinds of crucial activities (sharing key information or planning actions, etc.) based on communications. Accordingly, the reduction of inappropriate communications has been regarded as one of the key approaches in securing the safety of large process control systems, such as commercial airplanes, off-shore oil platforms and nuclear power plants (NPPs). This means that one of the practical methods would be the investigation of communication contents, through which we are able to identify useful insights pertaining to the prevention of inappropriate communications. For this reason, communications of main control room (MCR) operating crews that were faced with two kinds of abnormal operating conditions are analyzed to identify the variation of communication contents. To this end, in total 39 audio-visual records about abnormal training sessions, which were carried out by MCR operating crews, are collected from the full scope simulator of reference NPPs. Then communication contents and the associated crew performance data are compared for selected MCR operating crews. As a result, although additional effort is indispensable to draw a more concrete conclusion, it is strongly expected the performance of operating crews is proportional to the amount of '3-way communication.' In addition, it is necessary to develop a novel framework that can be used to analyze the communication characteristics of MCR operating crews because it is insufficient to retrieve insightful information from simple comparisons based on the empirical observation of crew communications

  2. Analysis of Dust Samples Collected from an Unused Spent Nuclear Fuel Interim Storage Container at Hope Creek, Delaware.

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, Charles R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Enos, David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-03-01

    In July, 2014, the Electric Power Research Institute and industry partners sampled dust on the surface of an unused canister that had been stored in an overpack at the Hope Creek Nuclear Generating Station for approximately one year. The foreign material exclusion (FME) cover that had been on the top of the canister during storage, and a second recently - removed FME cover, were also sampled. This report summarizes the results of analyses of dust samples collected from the unused Hope Creek canister and the FME covers. Both wet and dry samples of the dust/salts were collected, using SaltSmart(TM) sensors and Scotch - Brite(TM) abrasive pads, respectively. The SaltSmart(TM) samples were leached and the leachate analyzed chemically to determine the composition and surface load per unit area of soluble salts present on the canister surface. The dry pad samples were analyzed by X-ray fluorescence and by scanning electron microscopy to determine dust texture and mineralogy; and by leaching and chemical analysis to deter mine soluble salt compositions. The analyses showed that the dominant particles on the canister surface were stainless steel particles, generated during manufacturing of the canister. Sparse environmentally - derived silicates and aluminosilicates were also present. Salt phases were sparse, and consisted of mostly of sulfates with rare nitrates and chlorides. On the FME covers, the dusts were mostly silicates/aluminosilicates; the soluble salts were consistent with those on the canister surface, and were dominantly sulfates. It should be noted that the FME covers were w ashed by rain prior to sampling, which had an unknown effect of the measured salt loads and compositions. Sulfate salts dominated the assemblages on the canister and FME surfaces, and in cluded Ca - SO4 , but also Na - SO4 , K - SO4 , and Na - Al - SO4 . It is likely that these salts were formed by particle - gas conversion reactions, either

  3. Thermodynamical description of excited nuclei

    International Nuclear Information System (INIS)

    Bonche, P.

    1989-01-01

    In heavy ion collisions it has been possible to obtain composite systems at rather high excitation energies corresponding to temperatures of several MeV. The theoretical studies of these systems are based on concepts borrowed from thermodynamics or statistical physics, such as the temperature. In these lectures, we present the concepts of statistical physics which are involved in the physics of heavy ion as they are produced nowadays in the laboratory and also during the final stage of a supernova collapse. We do not attempt to describe the reaction mechanisms which yield such nuclear systems nor their decay by evaporation or fragmentation. We shall only study their static properties. The content of these lectures is organized in four main sections. The first one gives the basic features of statistical physics and thermodynamics necessary to understand quantum mechanics at finite temperature. In the second one, we present a study of the liquid-gas phase transition in nuclear physics. A phenomenological approach of the stability of hot nuclei follows. The microscopic point of view is proposed in the third part. Starting from the basic concepts derived in the first part, it provides a description of excited or hot nuclei which confirms the qualitative results of the second part. Furthermore it gives a full description of most properties of these nuclei as a function of temperature. Finally in the last part, a microscopic derivation of the equation of state of nuclear matter is proposed to study the collapse of a supernova core

  4. Consecutive collection of new finding and knowledge on science and technology to be reflected to seismic safety assessment for nuclear facilities

    International Nuclear Information System (INIS)

    Tsutsumi, Hideaki; Iijima, Toru

    2013-05-01

    JNES had been collecting and analyzing new finding and knowledge on science and technology to be reflected to seismic safety assessment for nuclear facilities, which was updated so as to develop a system to organize and disseminate such information in response to Nuclear Regulation Authority (NRA)'s policy on new safety regulations requesting enhanced protective measures against extreme natural hazards. The tasks were as follows; (1) collection of new finding and knowledge from seismic safety research of JNES, (2) constructing database of seismic safety research from documents published by committees and including the Great East Japan Earthquake and (3) dissemination of information related to seismic research. As for JFY 2012 activities, collecting and analyzing new finding and knowledge were on three areas such as active fault, seismic source/ground motion and tsunami. 4 theme related with the Great East Japan Earthquake, 7 items not related with the Great East Japan Earthquake and one item on external event were collected and analyzed whether incorporating in seismic safety research important for regulation to increase seismic safety of nuclear facilities, with no such theme confirmed. (T. Tanaka)

  5. Excitation-scanning hyperspectral imaging microscope

    Science.gov (United States)

    Favreau, Peter F.; Hernandez, Clarissa; Heaster, Tiffany; Alvarez, Diego F.; Rich, Thomas C.; Prabhat, Prashant; Leavesley, Silas J.

    2014-01-01

    Abstract. Hyperspectral imaging is a versatile tool that has recently been applied to a variety of biomedical applications, notably live-cell and whole-tissue signaling. Traditional hyperspectral imaging approaches filter the fluorescence emission over a broad wavelength range while exciting at a single band. However, these emission-scanning approaches have shown reduced sensitivity due to light attenuation from spectral filtering. Consequently, emission scanning has limited applicability for time-sensitive studies and photosensitive applications. In this work, we have developed an excitation-scanning hyperspectral imaging microscope that overcomes these limitations by providing high transmission with short acquisition times. This is achieved by filtering the fluorescence excitation rather than the emission. We tested the efficacy of the excitation-scanning microscope in a side-by-side comparison with emission scanning for detection of green fluorescent protein (GFP)-expressing endothelial cells in highly autofluorescent lung tissue. Excitation scanning provided higher signal-to-noise characteristics, as well as shorter acquisition times (300  ms/wavelength band with excitation scanning versus 3  s/wavelength band with emission scanning). Excitation scanning also provided higher delineation of nuclear and cell borders, and increased identification of GFP regions in highly autofluorescent tissue. These results demonstrate excitation scanning has utility in a wide range of time-dependent and photosensitive applications. PMID:24727909

  6. Multi-frequency excitation

    KAUST Repository

    Younis, Mohammad I.

    2016-03-10

    Embodiments of multi-frequency excitation are described. In various embodiments, a natural frequency of a device may be determined. In turn, a first voltage amplitude and first fixed frequency of a first source of excitation can be selected for the device based on the natural frequency. Additionally, a second voltage amplitude of a second source of excitation can be selected for the device, and the first and second sources of excitation can be applied to the device. After applying the first and second sources of excitation, a frequency of the second source of excitation can be swept. Using the methods of multi- frequency excitation described herein, new operating frequencies, operating frequency ranges, resonance frequencies, resonance frequency ranges, and/or resonance responses can be achieved for devices and systems.

  7. a simple a simple excitation control excitation control excitation

    African Journals Online (AJOL)

    eobe

    produce the primary dc fluxes are usually placed on the rotor because it has to (in most cases) sustain only a small fraction of the armature current. In situations ... concentrated on the var control of a synchronous motor and the study was extended to over-excitation schemes for power factor control of power lines to save.

  8. The Strategy Of Information Services Unit, BPM To Collect Tacit Knowledge Amongst The Officers Who Will Retire At The Malaysian Nuclear Agency

    International Nuclear Information System (INIS)

    Norzehan Ngadiron; Mohd Hafizal Yusof; Mohd Hasnor Hasan; Habibah Adnan; Rudarul Morhaya Ismail; Iberahim Ali

    2013-01-01

    This paper discusses the implementation strategies of Information Services Unit, Information Management Division (BPM) in collecting tacit knowledge among Malaysian Nuclear Agency officers before they entered retirement. Tacit knowledge is the knowledge of personnel (personal) owned by a person, consist the combination of knowledge, experience, wisdom and unique insight, and critical and stored in the individual. Therefore, efforts to collect tacit knowledge is designed to ensure that tacit knowledge can be stored and recorded either in the form of documents, visual audio, video and others. It is also to be used by internal and external users to enhance their knowledge and skills. It is hope that these efforts will contribute significantly to the survival of knowledge management activities in Malaysian Nuclear Agency. (author)

  9. Current puzzles in nuclear physics

    International Nuclear Information System (INIS)

    1985-01-01

    A meeting on ''Current puzzles in nuclear physics'' was held at Research Center for Nuclear Physics, Osaka University, on June 27 - 28, 1984. The meeting put emphasis on several puzzles which have not been solved for a long time in nuclear physics, and also on the puzzles. This collective report is composed of following eleven papers presented at the meeting. Almost all the papers are witten in English : (1) M1, GT excitations and configuration mixing (in Japanese). (2) Hadronic excitation of pionic states. (3) Microscopic analyses of 28 Si(α,α') 28 Si scattering and single particle strength in A = 29 nuclei. (4) Few-body physics and its incentives to nuclear physics. (5) Is it necessary to introduce three body interactions ? (in Japanese). (6) Puzzles in the neutron-deuteron elastic scattering. (7) Puzzles in NN, NΔ, πN and Nanti N interactions. (8) Problems in Hadron-Nucleus interaction. (9) Unified approach to the meson- and quark- theory of nuclear forces and currents. (10) Pion photoproduction in two Chiral bag models. (11) The dynamic bag model : The electromagnetic properties of nucleon. (Aoki, K.)

  10. Natural analogue of nuclear waste glass in a geologic formation. Study on long-term behavior of volcanic glass shards collected from drill cores

    International Nuclear Information System (INIS)

    Yoshikawa, Hideki; Yui, Mikazu; Futakuchi, Katsuhito; Hiroki, Minenari

    2005-01-01

    Alteration of the volcanic glass in geologic formation was investigated as one of the natural analog for a glass of high-level nuclear waste in geological disposal. We analyzed some volcanic glasses included in the core sample of the bore hole and estimated the history of its burying and observed its alteration using the polarizing microscope. Some information at the piling up temperature and the piling up time was collected. (author)

  11. Excitation modes in non-axial nuclei

    International Nuclear Information System (INIS)

    Leviatan, A.; Ginnochio, J.N.

    1990-01-01

    Excitation modes of non-axial quadrupole shapes are investigated in the framework of interacting boson models. Both γ-unstable and γ-rigid nuclear shapes are considered for systems with one type of boson as well as with proton-neutron bosons. 6 refs

  12. Excitation modes in non-axial nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Leviatan, A.; Ginnochio, J.N.

    1990-01-01

    Excitation modes of non-axial quadrupole shapes are investigated in the framework of interacting boson models. Both {gamma}-unstable and {gamma}-rigid nuclear shapes are considered for systems with one type of boson as well as with proton-neutron bosons. 6 refs.

  13. A comparison between the adiabatic time dependent Hartree-Fock and the generator coordinate methods for the description of nuclear collective motion

    International Nuclear Information System (INIS)

    Villars, F.

    1975-01-01

    The objective of the work is to draw attention to the essential equivalence of the two apparently quite distinct ways of describing nuclear collective dyanmics, the adiabatic time-dependent Hartree-Fock method (ADTHF) on the one hand, and the Generator Coordinate (GC) method on the other hand. To demonstrate this relation, an analysis of the simplest case, in which collective motion is described by a single collective para- meter q(t) is presented. In the ATDHF approach, two self-consistency conditions are obtained; the resultant expressions for the collective potential and kinetic energies represent a special case of the more general results of Baranger and Veneroni. In the G.C. approach to the same system (with the same collective parameter q), the narrow overlap approximation must be made, as the counterpart of the adiabatic approximation in the TDHF method. In its conventional form, the G.C. method leads to a different expression for the collective kinetic energy. It is shown however, that a simple generalization of the G.C.-wave function leads to corrections determined by a variational principle. In leading order, the corrected expression for the collective kinetic energy is identical with the TDHF result In both cases, the collective inertia is determined by a self-consistent cranking formula

  14. Theoretical Assessment of 178m2Hf De-Excitation

    Energy Technology Data Exchange (ETDEWEB)

    Hartouni, E P; Chen, M; Descalle, M A; Escher, J E; Loshak, A; Navratil, P; Ormand, W E; Pruet, J; Thompson, I J; Wang, T F

    2008-10-06

    This document contains a comprehensive literature review in support of the theoretical assessment of the {sup 178m2}Hf de-excitation, as well as a rigorous description of controlled energy release from an isomeric nuclear state.

  15. Approximate calculational techniques for radiation protection applications (collection of papers presented at the November 1985 American Nuclear Society meeting)

    Energy Technology Data Exchange (ETDEWEB)

    Rice, A.F.; Roussin, R.W. (comps.)

    1986-09-01

    Although radiation protection principles are, on the whole, well understood and a whole series of computer codes exist for their solution, it is felt that there is a need for practical, approximate techniques to be used by the practicing nuclear engineer for a variety of applications. Within the context of approximate techniques, the papers presented cover a broad overview of specific problems, for example, skyshine and penetration analysis, with applications extending from general nuclear reactor design to spent fuel storage and fusion. Separate abstracts have been prepared for individual papers.

  16. Approximate calculational techniques for radiation protection applications (collection of papers presented at the November 1985 American Nuclear Society meeting)

    International Nuclear Information System (INIS)

    Rice, A.F.; Roussin, R.W.

    1986-09-01

    Although radiation protection principles are, on the whole, well understood and a whole series of computer codes exist for their solution, it is felt that there is a need for practical, approximate techniques to be used by the practicing nuclear engineer for a variety of applications. Within the context of approximate techniques, the papers presented cover a broad overview of specific problems, for example, skyshine and penetration analysis, with applications extending from general nuclear reactor design to spent fuel storage and fusion. Separate abstracts have been prepared for individual papers

  17. Joliot-Curie School of Nuclear Physics, 1997

    International Nuclear Information System (INIS)

    Abgrall, Y.

    1998-01-01

    This document contains the lectures of the Joliot-Curie International School of Nuclear Physics held at Maubuisson, France on 8-13 September 1997. The following lectures of nuclear interest were given: The N-body problem (relativistic and non-relativistic approaches); The shell model (towards a unified of the nuclear structure); Pairing correlations in extreme conditions; Collective excitations in nuclei; Exotic nuclei (production, properties and specificities); Exotic nuclei (halos); Super and hyper deformation (from discrete to continuum, from EUROGAM to EUROBALL); and The spectroscopy of fission fragments. Important new facts are reported and discussed theoretically, concerning the nuclei in high excitation and high states and of the nuclei far off stability. Important technical achievements are reported among which the production of radioactive beams, sophisticated multi-detectors as well as significant advances in the nuclear theoretical methods. The double goal of training of young researchers and of permanent formation and information of the older ones seems to have been reached

  18. Systematics of nuclear mass and level density formulas

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Hisashi [Fuji Electric Co. Ltd., Kawasaki, Kanagawa (Japan)

    1998-03-01

    The phenomenological models of the nuclear mass and level density are close related to each other, the nuclear ground and excited state properties are described by using the parameter systematics on the mass and level density formulas. The main aim of this work is to provide in an analytical framework the improved energy dependent shell, pairing and deformation corrections generalized to the collective enhancement factors, which offer a systematic prescription over a great number of nuclear reaction cross sections. The new formulas are shown to be in close agreement with not only the empirical nuclear mass data but the measured slow neutron resonance spacings, and experimental systematics observed in the excitation energy dependent properties. (author)

  19. Nuclear structure at high excitation energies

    Indian Academy of Sciences (India)

    The present paper deals with the investigation of hot GDR and quadrupole shapes of 106;120Sn isotopes as a function of temperature and spin utilizing cranked quadrupole–quadrupole model interaction hamlitonian in the linear response theory and static path approximation to the grand canonical partition function.

  20. Internuclear potentials from heavy ion fusion excitation functions

    International Nuclear Information System (INIS)

    Birkelund, J.R.; Huizenga, J.R.

    1977-01-01

    A discussion is given of the determination of internuclear potentials from heavy ion fusion excitation functions. It is found that this calculation is complicated by the difficulties involved in a calculation of the frictional energy loss and by the problem of measurement of excitation function with sufficient accuracy to closely define the barrier radius. Any quantitative comparisons made between the nuclear potential derived from fusion data and theoretical nuclear potentials depend upon the solutions of the above problems. 15 references

  1. Nuclear Physics Laboratory: Annual report

    International Nuclear Information System (INIS)

    1987-05-01

    Topics covered in this annual report are: astrophysics and cosmology, giant resonances in excited nuclei, heavy ions, fundamental symmetries, nuclear reactions, accelerator mass spectrometry, accelerators and ion sources, nuclear instrumentation, computer systems and the booster linac project

  2. Search for Excited Leptons at LEP

    CERN Document Server

    Achard, P.; Aguilar-Benitez, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M.G.; Anderhub, H.; Andreev, Valery P.; Anselmo, F.; Arefev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay, L.; Baldew, S.V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.; Barillere, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B.L.; Biasini, M.; Biglietti, M.; Biland, A.; Blaising, J.J.; Blyth, S.C.; Bobbink, G.J.; Bohm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J.G.; Brochu, F.; Burger, J.D.; Burger, W.J.; Cai, X.D.; Capell, M.; Cara Romeo, G.; Carlino, G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Chamizo, M.; Chang, Y.H.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G.M.; Chen, H.F.; Chen, H.S.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.; Colino, N.; Costantini, S.; de la Cruz, B.; Cucciarelli, S.; van Dalen, J.A.; de Asmundis, R.; Deglon, P.; Debreczeni, J.; Degre, A.; Dehmelt, K.; Deiters, K.; della Volpe, D.; Delmeire, E.; Denes, P.; DeNotaristefani, F.; De Salvo, A.; Diemoz, M.; Dierckxsens, M.; Dionisi, C.; Dittmar, M.; Doria, A.; Dova, M.T.; Duchesneau, D.; Duda, M.; Echenard, B.; Eline, A.; El Hage, A.; El Mamouni, H.; Engler, A.; Eppling, F.J.; Extermann, P.; Falagan, M.A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson, T.; Fesefeldt, H.; Fiandrini, E.; Field, J.H.; Filthaut, F.; Fisher, P.H.; Fisher, W.; Fisk, I.; Forconi, G.; Freudenreich, K.; Furetta, C.; Galaktionov, Iouri; Ganguli, S.N.; Garcia-Abia, Pablo; Gataullin, M.; Gentile, S.; Giagu, S.; Gong, Z.F.; Grenier, Gerald Jean; Grimm, O.; Gruenewald, M.W.; Guida, M.; van Gulik, R.; Gupta, V.K.; Gurtu, A.; Gutay, L.J.; Haas, D.; Hakobyan, R.S.; Hansen, J.M.; Hatzifotiadou, D.; Hebbeker, T.; Herve, Alain; Hirschfelder, J.; Hofer, H.; Hohlmann, M.; Holzner, G.; Hou, S.R.; Hu, Y.; Jin, B.N.; Jones, Lawrence W.; de Jong, P.; Josa-Mutuberria, I.; Kafer, D.; Kaur, M.; Kienzle-Focacci, M.N.; Kim, J.K.; Kirkby, Jasper; Kittel, W.; Klimentov, A.; Konig, A.C.; Kopal, M.; Koutsenko, V.; Kraber, M.; Kraemer, R.W.; Kruger, A.; Kunin, A.; Ladron de Guevara, P.; Laktineh, I.; Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Le Goff, J.M.; Leiste, R.; Levtchenko, M.; Levtchenko, P.; Li, C.; Likhoded, S.; Lin, C.H.; Lin, W.T.; Linde, F.L.; Lista, L.; Liu, Z.A.; Lohmann, W.; Longo, E.; Lu, Y.S.; Luci, C.; Luminari, L.; Lustermann, W.; Ma, W.G.; Malgeri, L.; Malinin, A.; Mana, C.; Mans, J.; Martin, J.P.; Marzano, F.; Mazumdar, K.; McNeil, R.R.; Mele, S.; Merola, L.; Meschini, M.; Metzger, W.J.; Mihul, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G.B.; Muanza, G.S.; Muijs, A.J.M.; Musicar, B.; Musy, M.; Nagy, S.; Natale, S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Nisati, A.; Kluge, Hannelies; Ofierzynski, R.; Organtini, G.; Pal, I.; Palomares, C.; Paolucci, P.; Paramatti, R.; Passaleva, G.; Patricelli, S.; Paul, Thomas Cantzon; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix, D.; Petersen, B.; Piccolo, D.; Pierella, F.; Pioppi, M.; Piroue, P.A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofev, D.; Quartieri, J.; Rahal-Callot, G.; Rahaman, Mohammad Azizur; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P.G.; Ranieri, R.; Raspereza, A.; Razis, P.; Ren, D.; Rescigno, M.; Reucroft, S.; Riemann, S.; Riles, Keith; Roe, B.P.; Romero, L.; Rosca, A.; Rosier-Lees, S.; Roth, Stefan; Rosenbleck, C.; Rubio, J.A.; Ruggiero, G.; Rykaczewski, H.; Sakharov, A.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Schafer, C.; Schegelsky, V.; Schopper, H.; Schotanus, D.J.; Sciacca, C.; Servoli, L.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Son, D.; Souga, C.; Spillantini, P.; Steuer, M.; Stickland, D.P.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sultanov, G.; Sun, L.Z.; Sushkov, S.; Suter, H.; Swain, J.D.; Szillasi, Z.; Tang, X.W.; Tarjan, P.; Tauscher, L.; Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, Charles; Ting, Samuel C.C.; Ting, S.M.; Tonwar, S.C.; Toth, J.; Tully, C.; Tung, K.L.; Ulbricht, J.; Valente, E.; Van de Walle, R.T.; Vasquez, R.; Veszpremi, V.; Vesztergombi, G.; Vetlitsky, I.; Vicinanza, D.; Viertel, G.; Villa, S.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobev, I.; Vorobyov, A.A.; Wadhwa, M.; Wang, Q.; Wang, X.L.; Wang, Z.M.; Weber, M.; Wienemann, P.; Wilkens, H.; Wynhoff, S.; Xia, L.; Xu, Z.Z.; Yamamoto, J.; Yang, B.Z.; Yang, C.G.; Yang, H.J.; Yang, M.; Yeh, S.C.; Zalite, A.; Zalite, Yu.; Zhang, Z.P.; Zhao, J.; Zhu, G.Y.; Zhu, R.Y.; Zhuang, H.L.; Zichichi, A.; Zimmermann, B.; Zoller, M.

    2003-01-01

    A search for charged and neutral excited leptons is performed in 217 pb-1 of data collected with the L3 detector at LEP at centre-of-mass energies up to 209 GeV. The pair- and single-production mechanisms are investigated and no signals are detected. Combining with L3 results from searches at lower centre-of-mass energies, gives improved limits on the masses and couplings of excited leptons.

  3. Uniform magnetic excitations in nanoparticles

    DEFF Research Database (Denmark)

    Mørup, Steen; Hansen, Britt Rosendahl

    2005-01-01

    materials, quantum effects give rise to a small deviation from the linear temperature dependence of the (sublattice) magnetization at very low temperatures. The complex nature of the excited precession states of nanoparticles of antiferromagnetic materials, with deviations from antiparallel orientation......We have used a spin-wave model to calculate the temperature dependence of the (sublattice) magnetization of magnetic nanoparticles. The uniform precession mode, corresponding to a spin wave with wave vector q=0, is predominant in nanoparticles and gives rise to an approximately linear temperature...... dependence of the (sublattice) magnetization well below the superparamagnetic blocking temperature for both ferro-, ferri-, and antiferromagnetic particles. This is in accordance with the results of a classical model for collective magnetic excitations in nanoparticles. In nanoparticles of antiferromagnetic...

  4. Results of the scientific and technical activities of the Nuclear Reactors and Thermal Physics Institute for 2014. Scientific and technical collection

    International Nuclear Information System (INIS)

    Trufanov, A.A.; Sorokin, A.P.; Vereshchagina, T.N.

    2015-01-01

    In the collection there are the main results of research and development obtained by the researchers of the Nuclear Reactors and Thermal Physics Institute FSUE SSC RF - IPPE in 2014, the problems and questions of further investigations are formulated and discussed. Considerable body of data on neutronic, thermohydraulic and technological studies carried out in the frameworks of Proryv project are presented, calculational and experimental justification of design choices and safety of projects on RU BN-1200, multipurpose research reactor MBIR with sodium coolant, RU BREST-OD-300 with lead coolant are among them. The results of experimental and calculational thermophysical investigations in justification of operation conditions and safety of nuclear power plants with water-cooled reactors (WWER-1000, WWER-TOI), pilot studies on innovation project WWER-SKD with supercritical water, in justification of thermonuclear reactor blanket are given [ru

  5. A concept map aiding the knowledge management to build the collective knowledge in a nuclear organization - a case study: IEN

    International Nuclear Information System (INIS)

    Cussa, Adriana L.D.; Fonseca, Marcus Vinicius de A.

    2009-01-01

    This paper's proposition is to build and apply a tool to aid the knowledge management based in the intellectual capital as a value and competitiveness aggregator for a science, technology and innovation public organization in the Brazilian's nuclear area - the 'Instituto de Engenharia Nuclear - IEN'. It will be presented the hole survey of the finalistic activities and what has been considered the intellectual capital to be developed and strategically validated in its decision making practices. It was also surveyed the inter relations between the stakeholders, hereby the maintainer (CNEN), federal government, support foundations, public employees and contributors, in many different aspects focusing the continuity of research and development (R and D) activities and its results. As it is going to be detailed, the tool has been designed based in the concept map methodology using the Cmap tools software. The hole cognitive basis used here was constructed under disclosed and recognized knowledge models about knowledge, knowledge management, knowledge transference and intellectual capital. (author)

  6. Nuclear structure

    International Nuclear Information System (INIS)

    Eastham, D.A.; Joy, T.

    1986-01-01

    The paper on 'nuclear structure' is the Appendix to the Daresbury (United Kingdom) Annual Report 1985/86, and contains the research work carried out at the Nuclear Structure Facility, Daresbury, within that period. During the year a total of 74 experiments were scheduled covering the main areas of activity including: nuclear collective motion, nuclei far from stability, and nuclear collisions. The Appendix contains brief reports on these experiments and associated theory. (U.K.)

  7. Effect of pH on the release of radionuclides and chelating agents from cement-solidified decontamination ion-exchange resins collected from operating nuclear power stations

    Energy Technology Data Exchange (ETDEWEB)

    McIsaac, C.V.; Akers, D.W.; McConnell, J.W. (EG and G Idaho, Inc., Idaho Falls, ID (USA))

    1991-06-01

    Data are presented on the physical stability and leachability of radionuclides and chelating agents from cement-solidified decontamination ion-exchange resin wastes collected from two operating commercial light water reactors. Small-scale waste--form specimens collected during solidifications performed at the Brunswick Steam Electric Plant Unit 1 and at the James A. FitzPatrick Nuclear Power Station were leach-tested and subjected to compressive strength testing in accordance with the Nuclear Regulatory Commission's Technical Position on Waste Form'' (Revision 1). Samples of untreated resin waste collected from each solidification vessel before the solidification process were analyzed for concentrations of radionuclides, selected transition metals, and chelating agents to determine the quantities of these chemicals in the waste-form specimens. The chelating agents included oxalic, citric, and picolinic acids. In order to determine the effect of leachant chemical composition and pH on the stability and leachability of the waste forms, waste-form specimens were leached in various leachants. Results of this study indicate that differences in pH do not affect releases from cement-solidified decontamination ion-exchange resin waste forms, but that differences in leachant chemistry and the presence of chelating agents may affect the releases of radionuclides and chelating agents. Also, this study indicates that the cumulative releases of radionuclides and chelating agents are similar for waste- form specimens that decomposed and those that retained their general physical form. 36 refs., 60 figs., 28 tabs.

  8. Effect of pH on the release of radionuclides and chelating agents from cement-solidified decontamination ion-exchange resins collected from operating nuclear power stations

    International Nuclear Information System (INIS)

    McIsaac, C.V.; Akers, D.W.; McConnell, J.W.

    1991-06-01

    Data are presented on the physical stability and leachability of radionuclides and chelating agents from cement-solidified decontamination ion-exchange resin wastes collected from two operating commercial light water reactors. Small-scale waste--form specimens collected during solidifications performed at the Brunswick Steam Electric Plant Unit 1 and at the James A. FitzPatrick Nuclear Power Station were leach-tested and subjected to compressive strength testing in accordance with the Nuclear Regulatory Commission's ''Technical Position on Waste Form'' (Revision 1). Samples of untreated resin waste collected from each solidification vessel before the solidification process were analyzed for concentrations of radionuclides, selected transition metals, and chelating agents to determine the quantities of these chemicals in the waste-form specimens. The chelating agents included oxalic, citric, and picolinic acids. In order to determine the effect of leachant chemical composition and pH on the stability and leachability of the waste forms, waste-form specimens were leached in various leachants. Results of this study indicate that differences in pH do not affect releases from cement-solidified decontamination ion-exchange resin waste forms, but that differences in leachant chemistry and the presence of chelating agents may affect the releases of radionuclides and chelating agents. Also, this study indicates that the cumulative releases of radionuclides and chelating agents are similar for waste- form specimens that decomposed and those that retained their general physical form. 36 refs., 60 figs., 28 tabs

  9. Collection and use of individual behavioral and consumption rate data to improve reconstruction of thyroid doses from nuclear weapons tests in Kazakhstan

    International Nuclear Information System (INIS)

    Drozdovitch, Vladimir; Schonfeld, Sara; Bouville, Andre; Land, Charles; Luckyanov, Nick; Simon, Steven L.; Schwerin, Michael

    2008-01-01

    Full text: Historical behavioral and consumption rate data were collected from residents of Kazakhstan exposed to nuclear weapons testing fallout using a focus group data collection strategy. These data will enable improved thyroid dose estimation in a radiation epidemiological study being carried out the U.S. National Cancer Institute. The study on the relationship of radiation exposure from weapons testing fallout and thyroid disease in a cohort of 2,994 subjects is now in a stage of improving earlier dose estimates based on individual information collected from a basic questionnaire administered to the study population in 1998. The study subjects of both Kazakh and Russian origin were exposed during childhood to radioactive fallout from nuclear weapons tests conducted at the Semipalatinsk Nuclear Test Site between 1949 and 1962. Due to the long time since exposure, a well developed strategy is necessary to encourage accurate memory recall. Limitations of the data collected in 1998 suggested the need to obtain reliable information that is tailored specific to the requirements of the dose reconstruction algorithm and to the evaluation of individual dose uncertainties. Focus group data collection in Kazakhstan in 2007 involved four 8-person focus groups (three of women and one of men) in each of four exposed settlements where thyroid disease screening was conducted in 1998. Age-specific data on relevant childhood behaviour, including time spent indoors and consumption of milk and other dairy products from cows, goats, horses, and sheep, were collected from women's groups. Men's focus groups were interviewed about construction materials of houses and schools as well as animal grazing patterns and supplemental feed to animals. Information obtained from the focus groups are being used to derive the settlement-, ethnicity-, age-, and gender-specific (where appropriate) probability density distributions on individual consumption rates of milk and dairy products

  10. Interspecies nuclear transfer using fibroblasts from leopard, tiger, and lion ear piece collected postmortem as donor cells and rabbit oocytes as recipients.

    Science.gov (United States)

    Yelisetti, Uma Mahesh; Komjeti, Suman; Katari, Venu Charan; Sisinthy, Shivaji; Brahmasani, Sambasiva Rao

    2016-06-01

    Skin fibroblast cells were obtained from a small piece of an ear of leopard, lion, and tiger collected postmortem and attempts were made to synchronize the skin fibroblasts at G0/G1 of cell cycle using three different approaches. Efficiency of the approaches was tested following interspecies nuclear transfer with rabbit oocytes as recipient cytoplasm. Fluorescence-activated cell sorting revealed that the proportion of G0/G1 cells increased significantly (P lion, and tiger were successfully synchronized and used for the development of blastocysts using rabbit oocytes as recipient cytoplasm.

  11. Environmental law in Thuringia. Text collection with introduction. Pt. 1. Waste law, nuclear, radiation and energy law, soil protection law and land reparcelling, forestry law, fishing and hunting law

    International Nuclear Information System (INIS)

    Schneider, Matthias Werner

    2015-01-01

    The volume 1 of the collection on the Thuringian Environmental Law contains additional to a detailed introduction: - Waste management - Nuclear, radiation and energy law - Soil protection law and land reparcelling - Forestry, fishery and hunting law. [de

  12. Fission of highly excited nuclei investigated in complete kinematic measurements

    International Nuclear Information System (INIS)

    Rodriguez-Sanchez, J. L.; Benlliure, J.; Taieb, J.; Avarez-Pol, H.; Audouin, L.; Ayyad, Y.; Belier, G.; Boutoux, G.; Casarejos, E.; Chatillon, A.; Cortina-Gil, D.; Gorbinet, T.; Heinz, A.; Kelic-Heil, A.; Kurz, N.; Laurent, B.; Martin, J. F.; Paradela, C.; Pellereau, E.; Pietras, B.; Prochazka, A.; Ramos, D.; Rodriguez-Tajes, C.; Rossi, D.; Simon, H.; Tassan-Got, L.; Vargas, J.; Voss, B.

    2013-01-01

    Fission is an extremely complex mechanism that requires a dynamical approach to describe the evolution of the process in terms of intrinsic and collective excitations of the nuclear constituents. In order to determine these effects a complex experimental setup was mounted at GSI, which allowed us for the first time the full identification in charge and mass of all fission fragments thanks to a magnetic separation and the use of the inverse kinematic technique. Moreover, we also measured the neutron multiplicities and the light-charged particles emitted in coincidence with fission. These complete kinematic measurements will be used to define sensitive observables to dissipative and transient effects in fission. In this manuscript we present the first results for the total fission cross sections. (authors)

  13. Dynamical excitation in fission

    International Nuclear Information System (INIS)

    Ledergerber, T.; Paltiel, Z.; Fraenkel, Z.; Pauli, H.C.

    1976-01-01

    The excitation mechanism of the fission process is studied in terms of a model of particles moving in a deformed time-dependent potential. A residual interaction of the pairing type is incoporated by means of the BCS approximation. Only 2-quasi-particle excitations up to some cutoff energy are included. The separation of the total excitation energy into intrinsic and translational parts is made at the scission point. The present calculations for 240 Pu show that, in the framework of this model, most of the available energy at scission is transformed into intrinsic excitation energy. However the convergence of the calculated value for the cutoff energy is unsatisfactory and hence a description in terms of a better model space is needed. The fact that very many channels are involved suggests that a statistical treatment may be useful. (author)

  14. Determination of 129 I in biomonitors collected in the vicinity of a nuclear power plant by neutron activation analysis

    Czech Academy of Sciences Publication Activity Database

    Krausová, Ivana; Kučera, Jan; Světlík, Ivo

    2012-01-01

    Roč. 293, 13Sep2012 (2012), s. 1-6 ISSN 1588-2780 R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk(XE) LM2011019 Institutional support: RVO:61389005 Keywords : Iodine-129 * neutron activation analysis * biomonitor * nuclear power plant * Thyroid gland Subject RIV: CB - Analytical Chemistry, Separation http://download.springer.com/static/pdf/725/art%253A10.1007%252Fs10967-012-2200-5.pdf?auth66=1361263915_42267d28376ca81c4fc0de53c3cb59f4&ext=.pdf

  15. Determination of I-129 in biomonitors collected in the vicinity of a nuclear power plant by neutron activation analysis

    Czech Academy of Sciences Publication Activity Database

    Krausová, Ivana; Kučera, Jan; Světlík, Ivo

    2013-01-01

    Roč. 295, č. 3 (2013), s. 2043-2048 ISSN 0236-5731 R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk(XE) LM2011019 Institutional support: RVO:61389005 Keywords : I-129 * biomonitor * Thyroid gland * neutron activation analysis * nucelar power plant Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.415, year: 2013 http://link.springer.com/content/pdf/10.1007%2Fs10967-012-2200-5

  16. Partial level density of the n-quasiparticle excitations in the nuclei of the 40≤A≤200 region

    International Nuclear Information System (INIS)

    Sukhovoj, A.M.; Khitrov, V.A.

    2005-01-01

    Level density and radiative strength functions are obtained from the analysis of two-step cascades intensities following the thermal neutron capture. The data on level density are approximated by the sum of the partial level densities corresponding to n-quasiparticle excitations. The most probable values of the collective enhancement factor of the level density are found together with the thresholds of the next Cooper nucleons pair breaking. These data allow one to calculate the level density of practically any nucleus in given spin window in the framework of model concepts, taking into account all known nuclear excitation types. The presence of an approximation results discrepancy with theoretical statements specifies the necessity of rather essentially developing the level density models. It also indicates the possibilities to obtain the essentially new information on nucleon correlation functions of the excited nucleus from the experiment

  17. Collection and evaluation of complete and partial losses of off-site power at nuclear power plants

    International Nuclear Information System (INIS)

    Battle, R.E.

    1985-02-01

    Events involving loss of off-site power that have occurred at nuclear power plants through 1983 are described and categorized as complete or partial losses. The events were identified as plant-centered or grid-related failures. In addition, the causes of the failures were classified as weather, human error, design error, or hardware failure. The plant-centered failures were usually of shorter duration than the weather-related grid failures. For this reason, the weather-related events were reviewed in detail. Design features that may be important factors affecting off-site power system reliability were tabulated for most of the operating nuclear power plants. The tabulated information was provided to NRC for a statistical analysis to determine the importance of these design features for losses of off-site power. The frequency of losses of off-site power versus duration was estimated for three time periods. The frequency of loss of off-site power was estimated to be 0.09/reactor-year based on industry-wide data for the years 1959 through 1983

  18. Nuclear level density

    International Nuclear Information System (INIS)

    Cardoso Junior, J.L.

    1982-10-01

    Experimental data show that the number of nuclear states increases rapidly with increasing excitation energy. The properties of highly excited nuclei are important for many nuclear reactions, mainly those that go via processes of the compound nucleus type. In this case, it is sufficient to know the statistical properties of the nuclear levels. First of them is the function of nuclear levels density. Several theoretical models which describe the level density are presented. The statistical mechanics and a quantum mechanics formalisms as well as semi-empirical results are analysed and discussed. (Author) [pt

  19. Perspectives for photonuclear research at the Extreme Light Infrastructure - Nuclear Physics (ELI-NP) facility

    Energy Technology Data Exchange (ETDEWEB)

    Filipescu, D.; Balabanski, D.L.; Constantin, P.; Gales, S.; Tesileanu, O.; Ur, C.A.; Ursu, I.; Zamfir, N.V. [Horia Hulubei National Institute for R and D in Physics and Nuclear Engineering (IFIN-HH), Extreme Light Infrastructure - Nuclear Physics (ELI-NP), Bucharest-Magurele (Romania); Anzalone, A.; La Cognata, M.; Spitaleri, C. [INFN-LNS, Catania (Italy); Belyshev, S.S. [Lomonosov Moscow State University, Physics Faculty, Moscow (Russian Federation); Camera, F. [Departement of Physics, University of Milano, Milano (Italy); INFN section of Milano, Milano (Italy); Csige, L.; Krasznahorkay, A. [Hungarian Academy of Sciences (MTA Atomki), Institute of Nuclear Research, Post Office Box 51, Debrecen (Hungary); Cuong, P.V. [Vietnam Academy of Science and Technology, Centre of Nuclear Physics, Institute of Physics, Hanoi (Viet Nam); Cwiok, M.; Dominik, W.; Mazzocchi, C. [University of Warsaw, Warszawa (Poland); Derya, V.; Zilges, A. [University of Cologne, Institute for Nuclear Physics, Cologne (Germany); Gai, M. [University of Connecticut, LNS at Avery Point, Connecticut, Groton (United States); Gheorghe, I. [Horia Hulubei National Institute for R and D in Physics and Nuclear Engineering (IFIN-HH), Extreme Light Infrastructure - Nuclear Physics (ELI-NP), Bucharest-Magurele (Romania); University of Bucharest, Nuclear Physics Department, Post Office Box MG-11, Bucharest-Magurele (Romania); Ishkhanov, B.S. [Lomonosov Moscow State University, Physics Faculty, Moscow (Russian Federation); Lomonosov Moscow State University, Skobeltsyn Institute of Nuclear Physics, Moscow (Russian Federation); Kuznetsov, A.A.; Orlin, V.N.; Stopani, K.A.; Varlamov, V.V. [Lomonosov Moscow State University, Skobeltsyn Institute of Nuclear Physics, Moscow (Russian Federation); Pietralla, N. [Technische Universitat Darmstadt, Institut fur Kernphysik, Darmstadt (Germany); Sin, M. [University of Bucharest, Nuclear Physics Department, Post Office Box MG-11, Bucharest-Magurele (Romania); Utsunomiya, H. [Konan University, Department of Physics, Kobe (Japan); University of Tokyo, Center for Nuclear Study, Saitama (Japan); Weller, H.R. [Triangle Universities Nuclear Laboratory, North Carolina, Durham (United States); Duke University, Department of Physics, North Carolina, Durham (United States)

    2015-12-15

    The perspectives for photonuclear experiments at the new Extreme Light Infrastructure - Nuclear Physics (ELI-NP) facility are discussed in view of the need to accumulate novel and more precise nuclear data. The parameters of the ELI-NP gamma beam system are presented. The emerging experimental program, which will be realized at ELI-NP, is presented. Examples of day-one experiments with the nuclear resonance fluorescence technique, photonuclear reaction measurements, photofission experiments and studies of nuclear collective excitation modes and competition between various decay channels are discussed. The advantages which ELI-NP provides for all these experiments compared to the existing facilities are discussed. (orig.)

  20. Hidden multiparticle excitation in a weakly interacting Bose-Einstein condensate

    Science.gov (United States)

    Watabe, Shohei

    2018-03-01

    We investigate multiparticle excitation effect on a collective density excitation as well as a single-particle excitation in a weakly interacting Bose-Einstein condensate (BEC). We find that although the weakly interacting BEC offers weak multiparticle excitation spectrum at low temperatures, this multiparticle excitation effect may not remain hidden, but emerges as bimodality in the density response function through the single-particle excitation. Identification of spectra in the BEC between the single-particle excitation and the density excitation is also assessed at nonzero temperatures, which has been known to be unique nature in the BEC at absolute zero temperature.

  1. Nuclear structure

    International Nuclear Information System (INIS)

    Diamond, R.M.; Stephens, F.S.; Deleplanque, M.A.; Draper, J.E.; Dines, E.L.; Davis, U.C.; Macchiavelli, A.O.

    1984-01-01

    Essentially the whole range of spins possible for many nuclei in the periodic table is available with the use of the 88-Inch cyclotron and SuperHILAC accelerators. Nuclei carry angular momentum principally in two ways: by aligning individual high j nucleons, and by a collective rotation of the nucleus as a whole. Deformed nuclei use both modes and it is the interplay between the single-particle and collective modes that leads to the great diversity of nuclear properties at high spin. Information about these states and their properties is obtained only by detailed γ-ray spectroscopy of their de-exciting transitions. But for the higher spins the population is usually spread over so many states that only average values of continuum properties can be determined. So one of the goals of present-day research is to push discrete spectroscopic studies to higher spin states, reducing the continuum region. To do this requires that the number of cascade pathways observed be reduced to a small enough number so that individual transitions can show. One way is to use a combination of sum-energy and multiplicity selection, that is, to define a smaller entry region. This is what the NaI crystal balls can do. Another technique is to set gates on the highest-lying discrete transitions observed and look at what is in coincidence (ahead) of them. Either method requires a drastic decrease in the number of cascades selected, so very good statistics are needed and this means many detectors as close as possible to the target. The authors use both techniques simultaneously. Current and planned experiments are described

  2. Collection of Summaries of reports on result of research at basic experiment device for nuclear fusion reactor blanket design, 1994

    International Nuclear Information System (INIS)

    1995-07-01

    The development of nuclear fusion reactors reached such stage that the generation of fusion power output comparable with the input power into core plasma is possible. At present, the engineering design of the international thermonuclear fusion experimental reactor, ITER, is advanced by the cooperation of Japan, USA, Europe and Russia, aiming at the start of operation at the beginning of 21st century. This meeting for reporting the results has been held every year, and this time, it was held on May 19, 1995 at University of Tokyo with the theme ''The interface properties of fusion reactor materials and the control of particle transport''. About 50 participants from academic, governmental and industrial circles discussed actively on the theme. Three lectures on the topics of fusion reactor engineering and materials and seven lectures on the basic experiment of fusion reactor blanket design related to the next period project were given at the meeting. (K.I.)

  3. Face it: collecting mental health and disaster related data using Facebook vs. personal interview: the case of the 2011 Fukushima nuclear disaster.

    Science.gov (United States)

    Ben-Ezra, Menachem; Palgi, Yuval; Aviel, Or; Dubiner, Yonit; Evelyn Baruch; Soffer, Yechiel; Shrira, Amit

    2013-06-30

    Collecting mental health data during disaster is a difficult task. The aim of this study was to compare reported sensitive information regarding the disaster and general questions on physical or psychological functioning between social network (Facebook) interview and face-to-face interview after the 2011 Fukushima nuclear disaster. Data were collected from a battery of self-reported questionnaires. The questionnaires were administered to 133 face-to-face participants and to 40 Facebook interviewees, during March-April 2011. The face-to-face interview group showed a significantly higher level of posttraumatic stress disorder (PTSD) symptoms and elevated risk for clinical level of PTSD and reported more worries about another disaster, lower life satisfaction, less perceived social support and lower self-rated health than the Facebook group. Our data may suggest that the reliability of internet surveys is jeopardized during extreme conditions such as large-scale disasters as it tends to underestimate the reactions to such events. This indicates the discrepancy from data collected in situ to data collected using social networks. The implications of these results are discussed. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  4. Nuclear medicine at Camaguey, 1995-1999. Frequency of examinations and collective effective dose to the population; Medicina nuclear en Camaguey, 1995-1999. Frecuencia de examenes y dosis efectiva colectiva a la poblacion

    Energy Technology Data Exchange (ETDEWEB)

    Barreras, C. Aldo; Brigido, F. Osvaldo; Naranjo, L. Angela [Centro de Atencion a la Actividad Nuclear, Camaguey (Cuba)]. E-mail: sean@caonao.cmw.inf.cu; Lasserra, S. Oscar; Hernandez, G. Jose [Hospital Oncologico Maria Curie, Camaguey (Cuba)

    2001-07-01

    A study of the frequency of examinations for diagnosis in the territory of Camaguey-Ciego de Avila, Cuba, was made from the accumulated statistic in the period of 1995-1999 with the objective to obtain data to estimate the collective dose distributed to the population of this territory. It was determined that the annual frequency average of examinations was of 3,82 by each 1000 inhabitants. The obtained data allowed to evaluate the contribution of the different examinations from the collective dose, corresponding to the gamma radiographs of thyroid and pick up 43,73 and 43,36%, respectively, of the 54,43 Sv.man distributed to the population like annual. In this work the annual behavior of the collective dose for the studied period and its behavior in relation to the frequency of made examinations are analyzed. The smaller annual collective dose corresponded to 1996 with 39,05 Sv.man, while the greater value corresponded to 1999 with 66,67 Sv.man. The additional total damage for the studied period is considered: there would be 19,87 additional cases like result of 21073 nuclear medicine examinations, of which 13,6 correspond to mortal cancer. The obtained results are compared with the results reported for other countries.

  5. Seismic load experiments under mean seismic excitation

    International Nuclear Information System (INIS)

    Steinhilber, H.; Jehlicka, P.; Malcher, L.

    1979-01-01

    The seismic load experiments carried out within the framework of the HDR safety programme are aimed at enlarging and verifying the know-how with regard to the design of nuclear power plants so as to protect them against the impact of earth-quakes. One of the main objectives is to find out computing methods yielding sufficiently reliable results defining the actual vibrational behaviour of real structures under high seismic excitation. (orig./GL) [de

  6. Evaluation of the collection of periodical publications pertaining to CIDN (Nuclear Information and Documentation Center): Part I

    International Nuclear Information System (INIS)

    Contreras, T.J.

    1994-01-01

    The main purpose of this paper is to identify the lacks of the collection of periodical publications pertaining to CIDN as a function of the information needs of the researching community, considering that the research roles are in changing process. The library services of alert, selective dissemination of information, and interlibrary loan are analyzed. The results attained in the first stage of this study will help to take decisions about the titles that is necessary to put into the discard. (Author)

  7. Coulomb excitation of neutron-deficient polonium isotopes studied at ISOLDE

    CERN Document Server

    Neven, Michiel

    The polonium isotopes represent an interesting region of the nuclear chart having only two protons outside the Z = 82 closed shell. These isotopes have already been extensively studied theoretically and experimentally. The heavier isotopes (A > 200) seem to follow a "regular seniority-type regime" while for the lighter isotopes (A < 200) a more collective behavior is observed. Many questions remain regarding the transition between these two regimes and the configuration mixing between quantum states. Experiments in the lighter polonium isotopes point to the presence of shape coexistence, however the phenomenon is not fully understood. A Coulomb excitation study of the polonium isotopes whereby the dynamic properties are investigated can provide helpful insights in understanding the shape coexistence phenomena. In this thesis $^{202}$Po was studied via Coulomb excitation. The $^{202}$Po isotope was part of an experimental campaign in which the $^{196,198,200,206}$Po isotopes were studied as well via Coulomb...

  8. Shapes of Exotic Nuclei by Single- and Multi-Step Coulomb Excitation

    Science.gov (United States)

    Allmond, J. M.; Clarion-Bareball Collaboration; Gretina-Chico2 Collaboration

    2017-09-01

    Coulomb excitation is a powerful technique for probing the shell structure, collectivity, and shapes of atomic nuclei through the measurement of electromagnetic moments. Single- and multi-step Coulomb excitation results from CLARION-BareBall at HRIBF-ORNL (e.g., 136Te) and GRETINA-CHICO2 at CARIBU-ANL (e.g., 106Mo and 106,110Ru) will be presented. A survey of the equipment, techniques, and results will be given. An emphasis will be placed on unique opportunities with 3-MeV/u beams and future directions at CARIBU and ReA3. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics.

  9. Removal of Radiocesium from Food by Processing: Data Collected after the Fukushima Daiichi Nuclear Power Plant Accident - 13167

    International Nuclear Information System (INIS)

    Uchida, Shigeo; Tagami, Keiko

    2013-01-01

    Removal of radiocesium from food by processing is of great concern following the accident of TEPCO's Fukushima Daiichi Nuclear Power Plant accident. Foods in markets are monitored and recent monitoring results have shown that almost all food materials were under the standard limit concentration levels for radiocesium (Cs-134+137), that is, 100 Bq kg -1 in raw foods, 50 Bq kg -1 in baby foods, and 10 Bq kg -1 in drinking water; those food materials above the limit cannot be sold. However, one of the most frequently asked questions from the public is how much radiocesium in food would be removed by processing. Hence, information about radioactivity removal by processing of food crops native to Japan is actively sought by consumers. In this study, the food processing retention factor, F r , which is expressed as total activity in processed food divided by total activity in raw food, is reported for various types of corps. For white rice at a typical polishing yield of 90-92% from brown rice, the F r value range was 0.42-0.47. For leafy vegetable (indirect contamination), the average F r values were 0.92 (range: 0.27-1.2) after washing and 0.55 (range: 0.22-0.93) after washing and boiling. The data for some fruits are also reported. (authors)

  10. Removal of Radiocesium from Food by Processing: Data Collected after the Fukushima Daiichi Nuclear Power Plant Accident - 13167

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, Shigeo; Tagami, Keiko [Office of Biospheric Assessment for Waste Disposal, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-8555 (Japan)

    2013-07-01

    Removal of radiocesium from food by processing is of great concern following the accident of TEPCO's Fukushima Daiichi Nuclear Power Plant accident. Foods in markets are monitored and recent monitoring results have shown that almost all food materials were under the standard limit concentration levels for radiocesium (Cs-134+137), that is, 100 Bq kg{sup -1} in raw foods, 50 Bq kg{sup -1} in baby foods, and 10 Bq kg{sup -1} in drinking water; those food materials above the limit cannot be sold. However, one of the most frequently asked questions from the public is how much radiocesium in food would be removed by processing. Hence, information about radioactivity removal by processing of food crops native to Japan is actively sought by consumers. In this study, the food processing retention factor, F{sub r}, which is expressed as total activity in processed food divided by total activity in raw food, is reported for various types of corps. For white rice at a typical polishing yield of 90-92% from brown rice, the F{sub r} value range was 0.42-0.47. For leafy vegetable (indirect contamination), the average F{sub r} values were 0.92 (range: 0.27-1.2) after washing and 0.55 (range: 0.22-0.93) after washing and boiling. The data for some fruits are also reported. (authors)

  11. Excitation Methods for Bridge Structures

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, C.R.; Duffy, T.A.; Cornwell, P.J.; Doebling, S.W.

    1999-02-08

    This paper summarizes the various methods that have been used to excited bridge structures during dynamic testing. The excitation methods fall into the general categories of ambient excitation methods and measured-input excitation methods. During ambient excitation the input to the bridge is not directly measured. In contrast, as the category label implies, measured-input excitations are usually applied at a single location where the force input to the structure can be monitored. Issues associated with using these various types of measurements are discussed along with a general description of the various excitation methods.

  12. Quadrupole collectivity in {sup 128}Cd

    Energy Technology Data Exchange (ETDEWEB)

    Boenig, Esther Sabine

    2014-07-07

    The regions around shell closures, especially around doubly magic nuclei, are of major interest in nuclear structure physics, as they provide a perfect test for nuclear structure theory. The neutron-rich Cd isotopes in the region of {sup 132}Sn are only two protons away from the shell closure at Z=50 and in close proximity to the N=82 magic number. Nevertheless they show an irregular behaviour regarding the excitation energy of the first excited 2{sup +} state. This is not reproduced by shell model calculations, which is astonishing due to the proximity of the shell closures. In order to shed light on the much discussed region around doubly magic {sup 132}Sn, a Coulomb excitation experiment of {sup 128}Cd has been performed at REX-ISOLDE, CERN. The reduced transition strength B(E2;0{sup +}{sub gs} → 2{sup +}{sub 1}), which is a measure of collectivity, and the spectroscopic quadrupole moment Q{sub s}(2{sup +}{sub 1}) as a measure of deformation could be determined for the first time. The results are shown as the continuation of already measured neutron-rich Cd isotopes and are compared to both beyond mean field and shell model calculations, which give different predictions for these observables.

  13. An assessment of the radiological significance of consuming wild foods collected near the Sellafield nuclear fuel reprocessing plant

    International Nuclear Information System (INIS)

    Fulker, M.J.; McKay, K.; Jackson, D.; Leonard, D.R.P.

    1996-01-01

    Extensive monitoring of conventional agricultural produce in the vicinity of the BNFL Sellafield plant is undertaken, by both the operator and the Ministry of Agriculture, Fisheries and Food, to determine levels of radioactivity and douses arising to the consumer Monitoring is also undertaken, albeit less extensively, for market garden and domestic produce. By contrast, few data exist with respect to levels of radioactivity in 'wild foods' (e.g. hedgerow fruits, field mushrooms etc.) or associated consumption habits. It has been postulated that such foodstuffs could contribute an appreciable radiation exposure dose to groups of high level consumers, potentially including members of the existing identified critical group for local agricultural produce. This paper assess the actual radiological significance of wild foods collected near Sellafield. (author)

  14. Excitation of Stellar Pulsations

    DEFF Research Database (Denmark)

    Houdek, G.

    2012-01-01

    In this review I present an overview of our current understanding of the physical mechanisms that are responsible for the excitation of pulsations in stars with surface convection zones. These are typically cooler stars such as the δ Scuti stars, and stars supporting solar-like oscillations....

  15. Excitations and spin waves

    International Nuclear Information System (INIS)

    Lindgaard, P.-A.

    1978-01-01

    When neutron scattering data became available for the light rare earths (REs) and the RE compounds, a need was felt for a systematic theory for excitations in crystal-field dominated systems. The crystal field mixes the wavefunctions and provides a coupling between the ground state and the excited states for many operators, whereas for the Heisenberg system only J - has a nonzero matrix element to the first excited state. A review is given of successful applications of the theory in the interpretation of several experiments. The excitation spectrum for neutron scattering is simply given by the poles of the imaginary part of the enhanced wave-vector-dependent susceptibility tensor calculated in the random-phase approximation. A discussion of the effect of two-ion anisotropy is given. The formalism reduces to the conventional spin wave theory for the Heisenberg system when the crystal field is negligible compared to the exchange interaction. However, this theory has the drawback that it is necessary to know the crystal field in advance and each value of J must then be treated separately. A review of the results in the RE Laves-phase compounds and in the heavy rare earths is given, and the status of the current understanding of the interactions is rare earths and their compounds is discussed. (author)

  16. Hardness and excitation energy

    Indian Academy of Sciences (India)

    It is shown that the first excitation energy can be given by the Kohn-Sham hardness (i.e. the energy difference of the ground-state lowest unoccupied and highest occupied levels) plus an extra term coming from the partial derivative of the ensemble exchange-correlation energy with respect to the weighting factor in the ...

  17. Relativistic Coulomb excitation

    International Nuclear Information System (INIS)

    Winther, A.; Alder, K.

    1979-01-01

    Coulomb excitation of both target and projectile in relativistic heavy ion collisions is evaluated including the lowest order correction for the deviation from a straight line trajectory. Explicit results for differential and total cross sections are given in the form of tables and figures. (Auth.)

  18. Hardness and excitation energy

    Indian Academy of Sciences (India)

    ... the ground-state lowest unoccupied and highest occupied levels) plus an extra term coming from the partial derivative of the ensemble exchange-correlation energy with respect to the weighting factor in the limit → 0. It is proposed that the first excitation energy can be used as a reactivity index instead of the hardness.

  19. Effects of canine serum collected from dogs at different estrous cycle stages on in vitro nuclear maturation of canine oocytes.

    Science.gov (United States)

    Oh, Hyun Ju; Fibrianto, Yuda Heru; Kim, Min Kyu; Jang, Goo; Hossein, M Shamim; Kim, Hye Jin; Kang, Sung Keun; Lee, Byeong Chun; Hwang, Woo Suk

    2005-08-01

    Canine oocytes are ovulated at prophase of the first meiotic division and undergo maturation in the distal part of the oviduct for at least 48-72 h. Because of these differences from other domestic mammals, the efficiency of in vitro maturation (IVM) of canine oocyte is very low. The present study was conducted to evaluate the effects of canine serum on IVM of canine oocytes recovered from ovaries in various reproductive states (follicular, luteal or anestrous stages). Oocytes were recovered by mincing ovaries from bitches presented for ovariohysterectomy at various stages of the estrous cycle. Heat-inactivated canine serum was prepared with blood taken from dogs at the anestrous, estrous or diestrous stage of the estrous cycle as determined by progesterone concentration and vaginal cytology. Oocytes were cultured for 72 h in tissue culture medium (TCM)-199 supplemented with 10% canine anestrous, estrous or diestrous serum or fetal bovine serum (FBS) (experiment 1), or supplemented with 0 (control), 5%, 10% or 20% canine estrous serum (experiment 2). In experiment 1, IVM of oocytes collected at the follicular stage of the estrous cycle to metaphase II (MII) stage was higher (p canine estrous serum (14.2%) than with canine anestrous (5.2%) or diestrous serum (6.3%), FBS (2.2%) or in the control (2.2%). In experiment 2, oocytes collected at the follicular stage of the estrous cycle cultured in TCM-199 with 10% canine estrous serum showed a higher maturation rate to MII stage (13.5%, p canine estrous serum (5.1% MII) or the control (2.7% MII). In conclusion, our results demonstrate that supplementing culture medium with 10% canine estrous serum improves IVM of canine follicular stage oocytes.

  20. International symposium on exotic nuclear structures. Book of abstracst

    International Nuclear Information System (INIS)

    2000-01-01

    The following topics were discussed at the meeting: Physics of weakly bound nuclei, neutron skin and halo; Evolution of shell structures for neutron-rich nuclei; Collective excitations in nuclei with exotic nuclear shapes; Cluster structures; Super- and hyperdeformed nuclei, exotic structures in the actinides; Superheavy elements; Towards understanding the structure of nucleons; New experimental techniques, facilities for radioactive beams. All abstracts (75 items) were submitted as full text to the INIS database. (R.P.)

  1. Collective dose estimation in Portuguese population due to medical exams of diagnostic radiology and nuclear medicine; Estimativa da dose coletiva na populacao portuguesa devido a exames medicos de radiologia de diagnostico e de medicina nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Teles, Pedro; Vaz, Pedro [Instituto Tecnologico e Nuclear, Sacavem (Portugal). Instituto Superior Tecnico; Sousa, M. Carmen de [Instituto Portugues de Oncologia de Coimbra (Portugal); Paulo, Graciano; Santos, Joana [Escola Superior de Tecnologia da Saude de Coimbra (Portugal); Pascoal, Ana [Kings College Hospital, London (United Kingdom). Kings Health Partners; Cardoso, Gabriela; Santos, Ana isabel [Hospital Garcia de Orta, Almada (Portugal); Lanca, Isabel [Administracao Regional de Saude, Coimbra (Portugal); Matela, Nuno [Universidade de Lisboa (Portugal). Fac. de Ciencias. Instituto de Biofisica e Engenharia Biomedica; Janeiro, Luis [Escola superior de Saude da Cruz Vermelha Portuguesa, Lisboa (Portugal); Sousa, Patrick [Laboratorio de Instrumentacao e Fisica Experimental de Particulas, Lisboa (Portugal); Carvoeiras, Pedro; Parafita, Rui [Medical Consult, SA, Lisboa (Portugal); Simaozinho, Paula [Administracao Regional de Saude, Faro (Portugal)

    2013-11-01

    In order to assess the exposure of the Portuguese population to ionizing radiation due to medical examinations of diagnostic radiology and nuclear medicine, a working group, consisting of 40 institutions, public and private, was created to evaluation the coletive dose in the Portuguese population in 2010. This work was conducted in collaboration with the Dose Datamed European consortium, which aims to assess the exposure of the European population to ionizing radiation due to 20 diagnostic radiology examinations most frequent in Europe (the 'TOP 20') and nuclear medicine examinations. We obtained an average value of collective dose of Almost-Equal-To 1 mSv/caput, which puts Portugal in the category of countries medium to high exposure to Europe. We hope that this work can be a starting point to bridge the persistent lack of studies in the areas referred to in Portugal, and to enable the characterization periodic exposure of the Portuguese population to ionizing radiation in the context of medical applications.

  2. Whither Nuclear Physics ?

    OpenAIRE

    Abbas, Syed Afsar

    2008-01-01

    Nuclear Physics has had its ups and downs. However in recent years, bucked up by some new and often puzzling data, it has become a potentially very rich field. We review some of these exciting developments in a few important sectors of nuclear physics. Emphasis shall be on the study of exotic nuclei and the new physics that these nuclei are teaching us.

  3. Comparative study of the excitation functions of nuclear reactions induced by light ions (protons and α) and heavy ions (Ne, Ca, Ar) and, after neutron evaporation, leading to platinum and polonium isotopes. Analysis by de-excitation programme allowing for the angular momentum and fission

    International Nuclear Information System (INIS)

    Lagarde, Brigitte.

    1979-01-01

    This work is a study on the de-excitation of heavy nuclei from the Pt - Po area obtained by the complete fusion of various projectiles (p, 3 He, 4 He, 20 Ne, 40 Ar and 40 Ca) and of various targets. The aim was to create from different couples the same compound nucleus of a mass equal to the sum of the masses of the component parts. The excitation energy of the system thus created can vary between 60 and 120 MeV. The experimental study of one or more particular de-excitation channels performed by measuring the cross sections of residual nuclei production for various bombardment energies is a very conventional approach. An in depth examination was made of the effect of the angular momentum given to the compound nucleus by the input channel to the de-excitation processes. Now the population of orbital angular momenta depends essentially on the mass of the projectile at equal velocities. Consequently, the utilization of projectiles extending from the proton to mass 40 covers a wide range. Decay by neutrons is not the only de-excitation method. Fission has a significant role particularly for the Po's and consequently this strongly diminishes the probability (P,xn). The decay of (α,xn) when going from the compound nucleus of 204 Po to 182 Pt makes it possble to evaluate the importance of the phenomenon and to have an item of experimental information that can be compared to a theoretical calculation. Theoretical calculations using the 'ALICE' code which expresses schematically the reduction in level densities by subtracting from the excitation energy a rotation energy and the 'JULIAN' code which uses a more accurate level density calculation and takes into account the gamma emission competing with the emission of neutrons show that the last programme reports the experimental results whereas the 'ALICE' code does not enable a consistent presentation to be made of all the results by light and heavy ions. Finally, it had to be agreed that the fission does not intervene as

  4. Nuclear photonics

    Science.gov (United States)

    Habs, D.; Günther, M. M.; Jentschel, M.; Thirolf, P. G.

    2012-07-01

    With the planned new γ-beam facilities like MEGa-ray at LLNL (USA) or ELI-NP at Bucharest (Romania) with 1013 γ/s and a band width of ΔEγ/Eγ≈10-3, a new era of γ beams with energies up to 20MeV comes into operation, compared to the present world-leading HIγS facility at Duke University (USA) with 108 γ/s and ΔEγ/Eγ≈3ṡ10-2. In the long run even a seeded quantum FEL for γ beams may become possible, with much higher brilliance and spectral flux. At the same time new exciting possibilities open up for focused γ beams. Here we describe a new experiment at the γ beam of the ILL reactor (Grenoble, France), where we observed for the first time that the index of refraction for γ beams is determined by virtual pair creation. Using a combination of refractive and reflective optics, efficient monochromators for γ beams are being developed. Thus, we have to optimize the total system: the γ-beam facility, the γ-beam optics and γ detectors. We can trade γ intensity for band width, going down to ΔEγ/Eγ≈10-6 and address individual nuclear levels. The term "nuclear photonics" stresses the importance of nuclear applications. We can address with γ-beams individual nuclear isotopes and not just elements like with X-ray beams. Compared to X rays, γ beams can penetrate much deeper into big samples like radioactive waste barrels, motors or batteries. We can perform tomography and microscopy studies by focusing down to μm resolution using Nuclear Resonance Fluorescence (NRF) for detection with eV resolution and high spatial resolution at the same time. We discuss the dominating M1 and E1 excitations like the scissors mode, two-phonon quadrupole octupole excitations, pygmy dipole excitations or giant dipole excitations under the new facet of applications. We find many new applications in biomedicine, green energy, radioactive waste management or homeland security. Also more brilliant secondary beams of neutrons and positrons can be produced.

  5. Search for Excited Electrons in ep Collisions at HERA

    CERN Document Server

    Aaron, F.D.; Andreev, V.; Antunovic, B.; Aplin, S.; Asmone, A.; Astvatsatourov, A.; Bacchetta, A.; Backovic, S.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Beckingham, M.; Begzsuren, K.; Behnke, O.; Belousov, A.; Berger, N.; Bizot, J.C.; Boenig, M.-O.; Boudry, V.; Bozovic-Jelisavcic, I.; Bracinik, J.; Brandt, G.; Brinkmann, M.; Brisson, V.; Bruncko, D.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A.J.; Cantun Avila, K.B.; Cassol-Brunner, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Cholewa, A.; Contreras, J.G.; Coughlan, J.A.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Daum, K.; Deak, M.; de Boer, Y.; Delcourt, B.; Del Degan, M.; Delvax, J.; De Roeck, A.; De Wolf, E.A.; Diaconu, C.; Dodonov, V.; Dossanov, A.; Dubak, A.; Eckerlin, G.; Efremenko, V.; Egli, S.; Eliseev, A.; Elsen, E.; Essenov, S.; Falkiewicz, A.; Faulkner, P.J.W.; Favart, L.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Finke, L.; Fleischer, M.; Fomenko, A.; Gabathuler, E.; Gayler, J.; Ghazaryan, Samvel; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gouzevitch, M.; Grab, C.; Greenshaw, T.; Grell, B.R.; Grindhammer, G.; Habib, S.; Haidt, D.; Hansson, M.; Helebrant, C.; Henderson, R.C.W.; Henschel, H.; Herrera, G.; Hildebrandt, M.; Hiller, K.H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Hreus, T.; Jacquet, M.; Janssen, M.E.; Janssen, X.; Jemanov, V.; Jonsson, L.; Johnson, D.P.; Jung, Andreas Werner; Jung, H.; Kapichine, M.; Katzy, J.; Kenyon, I.R.; Kiesling, C.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knutsson, A.; Kogler, R.; Korbel, V.; Kostka, P.; Kraemer, M.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Kruger, K.; Kutak, K.; Landon, M.P.J.; Lange, W.; Lastovicka-Medin, G.; Laycock, P.; Lebedev, A.; Leibenguth, G.; Lendermann, V.; Levonian, S.; Li, G.; Lipka, K.; Liptaj, A.; List, B.; List, J.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.-I.; Lytkin, L.; Makankine, A.; Malinovski, E.; Marage, P.; Marti, Ll.; Martyn, H.-U.; Maxfield, S.J.; Mehta, A.; Meier, K.; Meyer, A.B.; Meyer, H.; Meyer, H.; Meyer, J.; Michels, V.; Mikocki, S.; Milcewicz-Mika, I.; Moreau, F.; Morozov, A.; Morris, J.V.; Mozer, Matthias Ulrich; Mudrinic, M.; Muller, K.; Murin, P.; Nankov, K.; Naroska, B.; Naumann, Th.; Newman, Paul R.; Niebuhr, C.; Nikiforov, A.; Nowak, G.; Nowak, K.; Nozicka, M.; Olivier, B.; Olsson, J.E.; Osman, S.; Ozerov, D.; Palichik, V.; Panagoulias, I.; Pandurovic, M.; Papadopoulou, Th.; Pascaud, C.; Patel, G.D.; Pejchal, O.; Peng, H.; Perez, E.; Petrukhin, A.; Picuric, I.; Piec, S.; Pitzl, D.; Placakyte, R.; Polifka, R.; Povh, B.; Preda, T.; Radescu, V.; Rahmat, A.J.; Raicevic, N.; Raspiareza, A.; Ravdandorj, T.; Reimer, P.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rotaru, M.; Ruiz Tabasco, J.E.; Rurikova, Z.; Rusakov, S.; Salek, D.; Salvaire, F.; Sankey, D.P.C.; Sauter, M.; Sauvan, E.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schoning, A.; Schultz-Coulon, H.-C.; Sefkow, F.; Shaw-West, R.N.; Sheviakov, I.; Shtarkov, L.N.; Shushkevich, S.; Sloan, T.; Smiljanic, Ivan; Smirnov, P.; Soloviev, Y.; Sopicki, P.; South, D.; Spaskov, V.; Specka, Arnd E.; Staykova, Z.; Steder, M.; Stella, B.; Straumann, U.; Sunar, D.; Sykora, T.; Tchoulakov, V.; Thompson, G.; Thompson, P.D.; Toll, T.; Tomasz, F.; Tran, T.H.; Traynor, D.; Trinh, T.N.; Truol, P.; Tsakov, I.; Tseepeldorj, B.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, K.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Vargas Trevino, A.; Vazdik, Y.; Vinokurova, S.; Volchinski, V.; Wegener, D.; Wessels, M.; Wissing, Ch.; Wunsch, E.; Yeganov, V.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zhu, Y.C.; Zimmermann, T.; Zohrabyan, H.; Zomer, F.

    2008-01-01

    A search for excited electrons is performed using the full $e^{\\pm}p$ data sample collected by the H1 experiment at HERA, corresponding to a total luminosity of 475 pb$^{-1}$. The electroweak decays of excited electrons ${e}^{*}\\to{e}{\\gamma}$, ${e}^{*}\\to{e}Z$ and ${e}^{*}{\\to}\

  6. Coulomb excitation of 73Ga

    CERN Document Server

    Diriken, J; Balabanski, D; Blasi, N; Blazhev, A; Bree, N; Cederkäll, J; Cocolios, T E; Davinson, T; Eberth, J; Ekström, A; Fedorov, D V; Fedosseev, V N; Fraille, L M; Franchoo, S; Georgiev, G; Gladnishki, K; Huyse, M; Ivanov, O V; Ivanov, V S; Iwanicki, V; Jolie, J; Konstantinopoulos, T; Kröll, Th; Krücken, R; Köster, U; Lagoyannis, A; Bianco, G Lo; Maierbeck, P; March, B A; Napiarkowski, P; Patronis, N; Pauwels, D; Reiter, P; Seliverstov, M; Sletten, G; Van de Walle, J; Van Duppen, P; Voulot, D; Walters, W B; Warr, N; Wenander, F; Wrzosek, K

    2010-01-01

    The B(E2; Ii ! If ) values for transitions in 71Ga and 73Ga were deduced from a Coulomb excitation experiment at the safe energy of 2.95 MeV/nucleon using post-accelerated beams of 71,73Ga at the REX-ISOLDE on-line isotope mass separator facility. The emitted gamma rays were detected by the MINIBALL-detector array and B(E2; Ii->If ) values were obtained from the yields normalized to the known strength of the 2+ -> 0+ transition in the 120Sn target. The comparison of these new results with the data of less neutron-rich gallium isotopes shows a shift of the E2 collectivity towards lower excitation energy when adding neutrons beyond N = 40. This supports conclusions from previous studies of the gallium isotopes which indicated a structural change in this isotopical chain between N = 40 and N = 42. Combined with recent measurements from collinear laser spectroscopy showing a 1/2- spin and parity for the ground state, the extracted results revealed evidence for a 1/2-; 3/2- doublet near the ground state in 73 31Ga...

  7. Joliot-Curie School of Nuclear Physics, 1997; Ecole Joliot-Curie de Physique Nucleaire, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Abgrall, Y. [L`Institut National de Physique Nucleaire et de Physique des Particules du CNRS (India2P3), 75 - Paris (France); Collaboration: La Direction des Sciences de la Matiere du CEA (FR); Le Fonds National de la Recherche Scientifique de Belgique (BE)

    1998-12-31

    This document contains the lectures of the Joliot-Curie International School of Nuclear Physics held at Maubuisson, France on 8-13 September 1997. The following lectures of nuclear interest were given: The N-body problem (relativistic and non-relativistic approaches); The shell model (towards a unified of the nuclear structure); Pairing correlations in extreme conditions; Collective excitations in nuclei; Exotic nuclei (production, properties and specificities); Exotic nuclei (halos); Super and hyper deformation (from discrete to continuum, from EUROGAM to EUROBALL); and The spectroscopy of fission fragments. Important new facts are reported and discussed theoretically, concerning the nuclei in high excitation and high states and of the nuclei far off stability. Important technical achievements are reported among which the production of radioactive beams, sophisticated multi-detectors as well as significant advances in the nuclear theoretical methods. The double goal of training of young researchers and of permanent formation and information of the older ones seems to have been reached

  8. Laser-excitation-source development

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    A number of schemes can be used to excite a gas laser, which introduces complexity in the search for the new laser because it requires the development of a host of advanced excitation sources. There are three demonstrated schemes for the excitation of a gas laser: (1) electron beam, (2) electric discharge, and (3) photolytic pumping. The photons for photypic pumping may be obtained with the other two excitation mechanisms in an external gas cell. Thus, from a power conditioning point of view, there are only two important excitation schemes, but each scheme has many different options. Research progress is reported on direct electric-discharge excitation development

  9. Evolution of the collective radiation dose of nuclear reactors from the 2nd through to the 3rd generation and 4th generation sodium-cooled fast reactors

    Science.gov (United States)

    Guidez, Joel; Saturnin, Anne

    2017-11-01

    During the operation of a nuclear reactor, the external individual doses received by the personnel are measured and recorded, in conformity with the regulations in force. The sum of these measurements enables an evaluation of the annual collective dose expressed in man·Sv/year. This information is a useful tool when comparing the different design types and reactors. This article discusses the evolution of the collective dose for several types of reactors, mainly based on publications from the NEA and the IAEA. The spread of good practices (optimization of working conditions and of the organization, sharing of lessons learned, etc.) and ongoing improvements in reactor design have meant that over time, the doses of various origins received by the personnel have decreased. In the case of sodium-cooled fast reactors (SFRs), the compilation and summarizing of various documentary resources has enabled them to be situated and compared to other types of reactors of the second and third generations (respectively pressurized water reactors in operation and EPR under construction). From these results, it can be seen that the doses received during the operation of SFR are significantly lower for this type of reactor.

  10. Search for Excited Quarks in ep Collisions at HERA

    CERN Document Server

    Aaron, F D; Alimujiang, K; Andreev, V; Antunovic, B; Asmone, A; Backovic, S; Baghdasaryan, A; Barrelet, E; Bartel, W; Begzsuren, K; Belousov, A; Bizot, J C; Boudry, V; Bozovic-Jelisavcic, I; Bracinik, J; Brandt, G; Brinkmann, M; Brisson, V; Bruncko, D; Bunyatyan, A; Buschhorn, G; Bystritskaya, L; Campbell, A J; Cantun Avila, K B; Cassol-Brunner, F; Cerny, K; Cerny, V; Chekelian, V; Cholewa, A; Contreras, J G; Coughlan, J A; Cozzika, G; Cvach, J; Dainton, J B; Daum, K; Deak, M; de Boer, Y; Delcourt, B; Del Degan, M; Delvax, J; De Roeck, A; De Wolf, E A; Diaconu, C; Dodonov, V; Dossanov, A; Dubak, A; Eckerlin, G; Efremenko, V; Egli, S; Eliseev, A; Elsen, E; Falkiewicz, A; Faulkner, P J W; Favart, L; Fedotov, A; Felst, R; Feltesse, J; Ferencei, J; Fischer, D J; Fleischer, M; Fomenko, A; Gabathuler, E; Gayler, J; Ghazaryan, S; Glazov, A; Glushkov, I; Goerlich, L; Gogitidze, N; Gouzevitch, M; Grab, C; Greenshaw, T; Grell, B R; Grindhammer, G; Habib, S; Haidt, D; Helebrant, C; Henderson, R C W; Hennekemper, E; Henschel, H; Herbst, M; Herrera, G; Hildebrandt, M; Hiller, K H; Hoffmann, D; Horisberger, R; Hreus, T; Jacquet, M; Janssen, M E; Janssen, X; Jemanov, V; Jonsson, L; Jung, Andreas Werner; Jung, H; Kapichine, M; Katzy, J; Kenyon, I R; Kiesling, C; Klein, M; Kleinwort, C; Kluge, T; Knutsson, A; Kogler, R; Korbel, V; Kostka, P; Kraemer, M; Krastev, K; Kretzschmar, J; Kropivnitskaya, A; Kruger, K; Kutak, K; Landon, M P J; Lange, W; Lastovicka-Medin, G; Laycock, P; Lebedev, A; Leibenguth, G; Lendermann, V; Levonian, S; Li, G; Lipka, K; Liptaj, A; List, B; List, J; Loktionova, N; Lopez-Fernandez, R; Lubimov, V; Lytkin, L; Makankine, A; Malinovski, E; Marage, P; Marti, Ll; Martyn, H U; Maxfield, S J; Mehta, A; Meyer, A B; Meyer, H; Meyer, H; Meyer, J; Michels, V; Mikocki, S; Milcewicz-Mika, I; Moreau, F; Morozov, A; Morris, J V; Mozer, Matthias Ulrich; Mudrinic, M; Muller, K; Murin, P; Naroska, B; Naumann, Th; Newman, P R; Niebuhr, C; Nikiforov, A; Nowak, G; Nowak, K; Nozicka, M; Olivier, B; Olsson, J E; Osman, S; Ozerov, D; Palichik, V; Panagoulias, I; Pandurovic, M; Papadopoulou, Th; Pascaud, C; Patel, G D; Pejchal, O; Perez, E; Petrukhin, A; Picuric, I; Piec, S; Pitzl, D; Placakyte, R; Pokorny, B; Polifka, R; Povh, B; Preda, T; Radescu, V; Rahmat, A J; Raicevic, N; Raspiareza, A; Ravdandorj, T; Reimer, P; Rizvi, E; Robmann, P; Roland, B; Roosen, R; Rostovtsev, A; Rotaru, M; Ruiz Tabasco, J E; Rurikova, Z; Rusakov, S; Salek, D; Sankey, D P C; Sauter, M; Sauvan, E; Schmitt, S; Schmitz, C; Schoeffel, L; Schoning, A; Schultz-Coulon, H C; Sefkow, F; Shaw-West, R N; Sheviakov, I; Shtarkov, L N; Shushkevich, S; Sloan, T; Smiljanic, Ivan; Soloviev, Y; Sopicki, P; South, D; Spaskov, V; Specka, Arnd E; Staykova, Z; Steder, M; Stella, B; Stoicea, G; Straumann, U; Sunar, D; Sykora, T; Tchoulakov, V; Thompson, G; Thompson, P D; Toll, T; Tomasz, F; Tran, T H; Traynor, D; Trinh, T N; Truol, P; Tsakov, I; Tseepeldorj, B; Turnau, J; Urban, K; Valkarova, A; Vallee, C; Van Mechelen, P; Vargas Trevino, A; Vazdik, Y; Vinokurova, S; Volchinski, V; von den Driesch, M; Wegener, D; Wissing, Ch; Wunsch, E; Zacek, J; Zalesak, J; Zhang, Z; Zhokin, A; Zimmermann, T; Zohrabyan, H; Zomer, F; Zus, R

    2009-01-01

    A search for excited quarks is performed using the full ep data sample collected by the H1 experiment at HERA, corresponding to a total integrated luminosity of 475 pb^-1. The electroweak decays of excited quarks q* -> q gamma, q* -> q Z and q* -> q W with subsequent hadronic or leptonic decays of the W and Z bosons are considered. No evidence for first generation excited quark production is found. Mass dependent exclusion limits on q* production cross sections and on the ratio f/Lambda of the coupling to the compositeness scale are derived within gauge mediated models. These limits extend the excluded region compared to previous excited quark searches.

  11. Isotope separation using vibrationally excited molecules

    International Nuclear Information System (INIS)

    Woodroffe, J.A.; Keck, J.C.

    1977-01-01

    A system for isotope separation or enrichment wherein molecules of a selected isotope type in a flow of molecules of plural isotope types are vibrationally excited and collided with a background gas to provide enhanced diffusivity for the molecules of the selected isotope type permitting their separate collection. The system typically is for the enrichment of uranium using a uranium hexafluoride gas in combination with a noble gas such as argon. The uranium hexafluoride molecules having a specific isotope of uranium are vibrationally excited by laser radiation. The vibrational energy is converted to a translation energy upon collision with a particle of the background gas and the added translation energy enhances the diffusivity of the selected hexafluoride molecules facilitating its condensation on collection surfaces provided for that purpose. This process is periodically interrupted and the cryogenic flow halted to permit evaporation of the collected molecules to provide a distinct, enriched flow

  12. Method of producing excited states of atomic nuclei

    International Nuclear Information System (INIS)

    Morita, M.; Morita, R.

    1976-01-01

    A method is claimed of producing excited states of atomic nuclei which comprises bombarding atoms with x rays or electrons, characterized in that (1) in the atoms selected to be produced in the excited state of their nuclei, (a) the difference between the nuclear excitation energy and the difference between the binding energies of adequately selected two electron orbits is small enough to introduce the nuclear excitation by electron transition, and (b) the system of the nucleus and the electrons in the case of ionizing an orbital electron in said atoms should satisfy the spin and parity conservation laws; and (2) the energy of the bombarding x rays or electrons should be larger than the binding energy of one of the said two electron orbits which is located at shorter distance from the atomic nucleus. According to the present invention, atomic nuclei can be excited in a relatively simple manner without requiring the use of large scale apparatus, equipment and production facilities, e.g., factories. It is also possible to produce radioactive substances or separate a particular isotope with an extremely high purity from a mixture of isotopes by utilizing nuclear excitation

  13. Kinetic energy in the collective quadrupole Hamiltonian from the experimental data

    Directory of Open Access Journals (Sweden)

    R.V. Jolos

    2017-06-01

    Full Text Available Dependence of the kinetic energy term of the collective nuclear Hamiltonian on collective momentum is considered. It is shown that the fourth order in collective momentum term of the collective quadrupole Hamiltonian generates a sizable effect on the excitation energies and the matrix elements of the quadrupole moment operator. It is demonstrated that the results of calculation are sensitive to the values of some matrix elements of the quadrupole moment. It stresses the importance for a concrete nucleus to have the experimental data for the reduced matrix elements of the quadrupole moment operator taken between all low lying states with the angular momenta not exceeding 4.

  14. Nuclear physics

    International Nuclear Information System (INIS)

    Kamal, Anwar

    2014-01-01

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

  15. Elementary excitations in single-chain magnets

    Science.gov (United States)

    Lutz, Philipp; Aguilà, David; Mondal, Abhishake; Pinkowicz, Dawid; Marx, Raphael; Neugebauer, Petr; Fâk, Björn; Ollivier, Jacques; Clérac, Rodolphe; van Slageren, Joris

    2017-09-01

    Single-chain magnets (SCMs) are one-dimensional coordination polymers or spin chains that display slow relaxation of the magnetization. Typically their static magnetic properties are described by the Heisenberg model, while the description of their dynamic magnetic properties is based on an Ising-like model. The types of excitations predicted by these models (collective vs localized) are quite different. Therefore we probed the nature of the elementary excitations for two SCMs abbreviated Mn2Ni and Mn2Fe , as well as a mononuclear derivative of the Mn2Fe chain, by means of high-frequency electron paramagnetic resonance spectroscopy (HFEPR) and inelastic neutron scattering (INS). We find that the HFEPR spectra of the chains are clearly distinct from those of the monomer. The momentum transfer dependence of the INS intensity did not reveal significant dispersion, indicating an essentially localized nature of the excitations. At the lowest temperatures these are modified by the occurrence of short-range correlations.

  16. Some light-ion excitation-function measurements on titanium, yttrium, and europium, and associated results

    Energy Technology Data Exchange (ETDEWEB)

    West, H.I. Jr. [ed.; Lanier, R.G.; Mustafa, M.G.; Nuckolls, R.M.; Nagle, R.J.; O`Brien, H. [Lawrence Livermore National Lab., CA (United States); Frehaut, J.; Adam, A.; Philis, C. [Service de Physique et Techniques Nucleaires, Centre d`Etudes Bruyeres-le-Chatel, Boite Postale 12 (France)

    1993-11-01

    This report discusses: Fabrication of Plastic-Matrix-Encapsulated Accelerator Targets and Their Use in Measuring Nuclear Excitation Functions; Correcting Excitation Function Data in the Low Energy Region for Finite Thickness of the Target Foils, Including Effects of Straggling; Excitation Functions for the Nuclear Reactions on Titanium Leading to the Production {sup 48}V, {sup 44}Sc and {sup 47}Sc by Proton, Deuteron and Triton Irradiations at 0--35 MeV; Some Excitation Functions of Proton and Deuteron Induced Reactions on {sup 89}Y; Measurements of the Excitation Functions of the Isobaric Chain {sup 87}Y, {sup 87}Y{sup m}, {sup 87}Y{sup g} and {sup 87}Sr{sup m}; Levels in {sup 87}Y Observed in the Decay of {sup 87}Zr; and Nuclear Reaction Excitation Functions from the Irradiation of {sup 151,153}Eu with Protons And deuterons up to 35 MeV.

  17. Electron-induced excitation of 93Mo

    Science.gov (United States)

    Chiara, C. J.; Carroll, J. J.; Marsh, J. C.; Matters, D. A.; Lane, G. J.; Hartley, D. J.; Polasik, M.; Rzadkiewicz, J.; Carpenter, M. P.; Greene, J. P.; Janssens, R. V. F.; Seweryniak, D.; Zhu, S.

    2016-09-01

    The inverse of the internal-conversion process, whereby a free electron is captured into an atomic orbital and subsequently excites the nucleus to a higher-lying state via a virtual energy exchange, was predicted to exist 40 years ago but has yet to be demonstrated experimentally. To search for this mode of nuclear excitation by electron capture, we performed an experiment at the ATLAS facility at Argonne National Laboratory. The t1/2 = 6.85-h, 21/2+ state of 93Mo was populated in the 7Li(90Zr, p 3 n) reaction. The excitation mechanism was predicted to induce depopulation of this isomer as the fast-moving 93mMo recoils slowed in the target material, emitting a characteristic sequence of γ rays in the process. Results of the search for these signature γ rays using Digital Gammasphere will be presented. This material is based upon work supported by the US DOE, Office of Science, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357. This research used resources of ANL's ATLAS facility, which is a DOE Office of Science User Facility.

  18. Nuclear muon capture - theoretical aspects

    International Nuclear Information System (INIS)

    Mukhopadhyay, N.C.

    1978-01-01

    Nuclear muon capture processes are considered with especial reference to particle physics interests and the possibility of probing aspects of nuclear structure such as nuclear symmetries, cluster correlations and giant resonance excitations. The question of the adequacy of the free muon-nucleon weak interaction inputs in an impulse approximation treatment of the muon capture by complex nuclei is examined. (U.K.)

  19. Harmonically excited orbital variations

    International Nuclear Information System (INIS)

    Morgan, T.

    1985-01-01

    Rephrasing the equations of motion for orbital maneuvers in terms of Lagrangian generalized coordinates instead of Newtonian rectangular cartesian coordinates can make certain harmonic terms in the orbital angular momentum vector more readily apparent. In this formulation the equations of motion adopt the form of a damped harmonic oscillator when torques are applied to the orbit in a variationally prescribed manner. The frequencies of the oscillator equation are in some ways unexpected but can nonetheless be exploited through resonant forcing functions to achieve large secular variations in the orbital elements. Two cases are discussed using a circular orbit as the control case: (1) large changes in orbital inclination achieved by harmonic excitation rather than one impulsive velocity change, and (2) periodic and secular changes to the longitude of the ascending node using both stable and unstable excitation strategies. The implications of these equations are also discussed for both artificial satellites and natural satellites. For the former, two utilitarian orbits are suggested, each exploiting a form of harmonic excitation. 5 refs

  20. The137Cs activity concentration of suspended and dissolved fractions in irrigation waters collected from the 80 km zone around TEPCO's Fukushima Daiichi Nuclear Power Station.

    Science.gov (United States)

    Tsukada, Hirofumi; Nihira, Satoshi; Watanabe, Takashi; Takeda, Satoru

    2017-11-01

    Fifty-four samples of irrigation water were collected in 2014 from agricultural ponds, rivers, and dams within the 80 km zone around TEPCO's Fukushima Daiichi Nuclear Power Station (FDNPS). The samples were filtered with a 0.45 μm pore-size membrane filter to produce suspended and dissolved fractions. The 137 Cs activity concentration of the suspended fraction varied from 1.5 to 300 Bq g -1 dry weight and was significantly higher than that in the soil around each sampling site. The range of 137 Cs activity concentrations in the dissolved fraction varied over three orders of magnitude at 0.0075-6.7 Bq l -1 , which was a larger range than that of the suspended fraction; the higher values for samples were from within the 20 km zone. In the dissolved fraction 87 ± 9% of the 137 Cs (n = 37) was in a monovalent cationic form (Cs + ) and therefore potentially mobile. The distribution coefficient (Kd) ranged from 4100 to 2,100,000; the geometric mean value (110,000) was higher than that reported by the IAEA (2010). The geometric mean Kd of samples collected from the 20 km zone was 61,000 (n = 27), which was significantly lower than that collected from 20 to 80 km zone (200,000, n = 27). The Kd-value was negative correlated with the concentration of stable 133 Cs and the electric conductivity in the dissolved fraction. This shows relatively higher mobility of radiocaesium in irrigation waters may occur when there are higher contents of cations present. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Search for excited charged leptons in electron positron collisions

    CERN Document Server

    Vachon, Brigitte Marie Christine; Sobie, Randall

    2002-01-01

    A search for evidence that fundamental particles are made of smaller subconstituents is performed. The existence of excited states of fundamental particles would be an unambiguous indication of their composite nature. Experimental signatures compatible with the production of excited states of charged leptons in electron-positron collisions are studied. The data analysed were collected by the OPAL detector at the LEP collider. No evidence for the existence of excited states of charged leptons was found. Upper limits on the product of the cross-section and the electromagnetic branching fraction are inferred. Using results from the search for singly produced excited leptons, upper limits on the ratio of the excited lepton coupling constant to the compositeness scale are calculated. From pair production searches, 95% confidence level lower limits on the masses of excited electrons, muons and taus are determined to be 103.2 GeV.

  2. Evolution of nuclear shape in the light radon isotopes

    CERN Multimedia

    Reiter, P; Blazhev, A A; Kruecken, R; Rahkila, P J; Grahn, T; Wadsworth, R; Gernhaeuser, R A; Bree, N C F; Habs, D; Jenkins, D G; Huyse, M L

    2008-01-01

    We propose to carry out Coulomb excitation of post-accelerated beams of $^{202,204}$ Rn from the REX-ISOLDE facility. The aim of this study is to expand our understanding of nuclear shape coexistence, which has been increasingly well-established in the light mercury and lead nuclei to these very heavy nuclei. Such an extension will provide stringent tests of nuclear models of collectivity and shape coexistence in a previously-inaccessible heavy mass region. REX- ISOLDE is the only facility worldwide at the present time which can provide accelerated beams of such heavy radioactive nuclei.

  3. Electron-driven excitations and dissociation of molecules

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Greg [Univ. of California, Davis, CA (United States); Orel, Ann E. [Univ. of California, Davis, CA (United States)

    2015-02-13

    This program studied how energy is interchanged in electron and photon collisions with molecules leading to ex-citation and dissociation. Modern ab initio techniques, both for the photoionization and electron scattering, and the subsequent nuclear dynamics studies, are used to accurately treat these problems. This work addresses vibrational ex-citation and dissociative attachment following electron impact, and the dynamics following inner shell photoionzation. These problems are ones for which a full multi-dimensional treatment of the nuclear dynamics is essential and where non-adiabatic effects are expected to be important.

  4. Seismic analysis of piping systems subjected to multiple support excitations

    International Nuclear Information System (INIS)

    Sundararajan, C.; Vaish, A.K.; Slagis, G.C.

    1981-01-01

    The paper presents the results of a comparative study between the multiple response spectrum method and the time-history method for the seismic analysis of nuclear piping systems subjected to different excitation at different supports or support groups. First, the necessary equations for the above analysis procedures are derived. Then, three actual nuclear piping systems subjected to single and multiple excitations are analyzed by the different methods, and extensive comparisons of the results (stresses) are made. Based on the results, it is concluded that the multiple response spectrum analysis gives acceptable results as compared to the ''exact'', but much more costly, time-history analysis. 6 refs

  5. Proceedings of the 9th national conference on nuclear electronics and nuclear detection technology

    International Nuclear Information System (INIS)

    1999-01-01

    It is the proceedings of the 9th national conference on nuclear electronics and nuclear technology. 114 theses are collected in this proceedings. It includes nuclear electronics, nuclear detector, radiation hardened electronics, computer application in nuclear sciences and technology, nuclear instruments and its application, nuclear monitoring and nuclear explosion measurement, nuclear medical electronics and liquid scintillation counting technology

  6. Lifetime measurements of excited Co I levels

    CERN Document Server

    Klotz, W D; Gobel, L H

    1977-01-01

    In the region of 3500 AA the lifetimes of eight excited Cobalt I levels have been measured by means of the zero field level crossing method. The measured lifetimes belong to the odd configurations 3d/sup 7/4s4p and 3d/sup 8/4p and are of the accuracy of about 5%. The hyperfine structure of levels with I not=J has to be taken into account in evaluating lifetimes from level crossing data, because the nuclear spin of the natural isotope /sup 59/Co is I=7/2. Therefore the influence of the line profile of the exciting resonance lines on the lifetimes has been investigated. The results are compared with those of other authors. Furthermore absolute oscillator strengths were calculated with known branching ratios and a new absolute scale has been established. (23 refs).

  7. Ionization of excited hydrogen and excited hydrogen-like ions in collisions with bare ions

    International Nuclear Information System (INIS)

    Igarashi, Akinori; Shirai, Toshizo

    1995-01-01

    Accompanying the heightening of the density of nuclear fusion plasma and the heightening of the energy of incident atoms, attention has been paid to multi-stage collision excitation process. This collision process possesses a large cross section, and the evaluation of the cross section is an urgent task to analyze the efficiency of plasma heating. In this study, by using CDW-EIS approximation, of which the calculation is relatively easy, the ionization cross section in the collision of bare ions with excited state hydrogen and hydrogen-like ions was calculated. The CDW-EIS approximation was introduced by Crothers and McCann, and it is the high energy approximation that reproduces best the experimental data on the ionization cross section of ground state hydrogen by bare ions. It was confirmed by the result of make-up calculation that if energy becomes high to some extent, the CDW-EIS approximation and Born approximation approach and agree for the ionization from ground state and also from excited state. The results of the ionization collision of bare ions with excited hydrogen atoms and excited hydrogen-like ions are reported. (K.I.)

  8. Students Excited by Stellar Discovery

    Science.gov (United States)

    2011-02-01

    follow-up observations, and Thompson joined online. "Observing with the students is very exciting. It gives the students a chance to learn about radio telescopes and pulsar observing in a very hands-on way, and it is extra fun when we find a pulsar," said Rosen. Snider, on the other hand, said, "I got very, very nervous. I expected when I went there that I would just be watching other people do things, and then I actually go to sit down at the controls. I definitely didn't want to mess something up." Everything went well, and the observations confirmed that the students had found an exotic pulsar. "I learned more in the two hours in the control room than I would have in school the whole day," Mabry said. Pulsars are spinning neutron stars that sling lighthouse beams of radio waves or light around as they spin. A neutron star is what is left after a massive star explodes at the end of its normal life. With no nuclear fuel left to produce energy to offset the stellar remnant's weight, its material is compressed to extreme densities. The pressure squeezes together most of its protons and electrons to form neutrons; hence, the name neutron star. One tablespoon of material from a pulsar would weigh 10 million tons -- as much as a supertanker. The object that the students discovered is in a special class of pulsar that spins very fast - in this case, about 30 times per second, comparable to the speed of a kitchen blender. "The big question we need to answer first is whether this is a young pulsar or a recycled pulsar," said Maura McLaughlin, an astronomer at WVU. "A pulsar spinning that fast is very interesting as it could be newly born or it could be a very old, recycled pulsar." A recycled pulsar is one that was once in a binary system. Material from the companion star is deposited onto the pulsar, causing it to speed up, or be recycled. Mystery remains, however, about whether this pulsar has ever had a companion star. If it did, "it may be that this pulsar had a massive

  9. Highly excited atoms

    International Nuclear Information System (INIS)

    Kleppner, D.; Littman, M.G.; Zimmerman, M.L.

    1981-01-01

    Highly excited atoms are often called Rydberg atoms. These atoms have a wealth of exotic properties which are discussed. Of special interest, are the effects of electric and magnetic fields on Rydberg atoms. Ordinary atoms are scarcely affected by an applied electric or magnetic field; Rydberg atoms can be strongly distorted and even pulled apart by a relatively weak electric field, and they can be squeezed into unexpected shapes by a magnetic field. Studies of the structure of Rydberg atoms in electric and magnetic fields have revealed dramatic atomic phenomena that had not been observed before

  10. Excited QCD 2017

    CERN Document Server

    2017-01-01

    This edition is the ninth in a series of workshops that had been previously organised in Poland (2009), Slovakia (2010 and 2015), France (2011), Portugal (2012 and 2016) and Bosnia and Herzegovina (2013 and 2014). In the year 2017 the workshop goes to the beautiful Sintra near Lisbon, Portugal. The workshop covers diverse aspects of QCD: (i) QCD at low energies: excited hadrons, new resonances, glueballs, multiquarks. (ii) QCD at high temperatures and large densities: heavy-ion collisions, jets, diffraction, hadronisation, quark-gluon plasma, holography, colour-glass condensate, compact stars, applications to astrophysics.

  11. Estimation of the collective ionizing dose in the Portuguese population for the years 2011 and 2012, due to nuclear medicine exams.

    Science.gov (United States)

    Costa, F; Teles, P; Nogueira, A; Barreto, A; Santos, A I; Carvalho, A; Martins, B; Oliveira, C; Gaspar, C; Barros, C; Neves, D; Costa, D; Rodrigues, E; Godinho, F; Alves, F; Cardoso, G; Cantinho, G; Conde, I; Vale, J; Santos, J; Isidoro, J; Pereira, J; Salgado, L; Rézio, M; Vieira, M; Simãozinho, P; Almeida, P; Castro, R; Parafita, R; Pintão, S; Lúcio, T; Reis, T; Vaz, P

    2015-01-01

    In 2009-2010 a Portuguese consortium was created to implement the methodologies proposed by the Dose Datamed II (DDM2) project, aiming to collect data from diagnostic X-ray and nuclear medicine (NM) procedures, in order to determine the most frequently prescribed exams and the associated ionizing radiation doses for the Portuguese population. The current study is the continuation of this work, although it focuses only on NM exams for the years 2011 and 2012. The annual frequency of each of the 28 selected NM exams and the average administered activity per procedure was obtained by means of a nationwide survey sent to the 35 NM centres in Portugal. The results show a reduction of the number of cardiac exams performed in the last two years compared with 2010, leading to a reduction of the annual average effective dose of Portuguese population due to NM exams from 0.08 mSv ± 0.017 mSv/caput to 0.059 ± 0.011 mSv/caput in 2011 and 0.054 ± 0.011 mSv/caput in 2012. Portuguese total annual average collective effective dose due to medical procedures was estimated to be 625.6 ± 110.9 manSv in 2011 and 565.1 ± 117.3 manSv in 2012, a reduction in comparison with 2010 (840.3 ± 183.8 manSv). The most frequent exams and the ones that contributed the most for total population dose were the cardiac and bone exams, although a decrease observed in 2011 and in 2012 was verified. The authors intend to perform this study periodically to identify trends in the annual Portuguese average effective dose and to help to raise awareness about the potential dose optimization. Copyright © 2014 Elsevier España, S.L.U. and SEMNIM. All rights reserved.

  12. Calculation of excitation functions of the 54, 56, 57, 58 Fe (p, n ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 83; Issue 4. Calculation of ... The excitation functions have been compared with experimental nuclear data. ... Proton-induced reaction cross-sections provide clues to understand the nuclear structure and offers a good testing ground for ideas about nuclear forces.

  13. Compression and immersion tests and leaching of radionuclides, stable metals, and chelating agents from cement-solidified decontamination waste collected from nuclear power stations

    International Nuclear Information System (INIS)

    Akers, D.W.; Kraft, N.C.; Mandler, J.W.

    1994-06-01

    A study was performed for the Nuclear Regulatory Commission (NRC) to evaluate structural stability and leachability of radionuclides, stable metals, and chelating agents from cement-solidified decontamination ion-exchange resin wastes collected from seven commercial boiling water reactors and one pressurized water reactor. The decontamination methods used at the reactors were the Can-Decon, AP/Citrox, Dow NS-1, and LOMI processes. Samples of untreated resin waste and solidified waste forms were subjected to immersion and compressive strength testing. Some waste-form samples were leach-tested using simulated groundwaters and simulated seawater for comparison with the deionized water tests that are normally performed to assess waste-form leachability. This report presents the results of these tests and assesses the effects of the various decontamination methods, waste form formulations, leachant chemical compositions, and pH of the leachant on the structural stability and leachability of the waste forms. Results indicate that releases from intact and degraded waste forms are similar and that the behavior of some radionuclides such as 55 Fe, 60 Co, and 99 Tc were similar. In addition, the leachability indexes are greater than 6.0, which meets the requirement in the NRC's ''Technical Position on Waste Form,'' Revision 1

  14. The institutionalisation of ecological standpoint in modern societies: Responses of collective actors to the ecological challenge in the debate on nuclear energy. Final report

    International Nuclear Information System (INIS)

    Jahn, D.; Eickoff, V.; Neudorf, S.; Siegmund, A.; Siegmund, K.; Wilting, D.

    1994-11-01

    We developped a concept for the analysis of the institutionalisation of ecological standpoints in modern societies in order to apply a content analysis on the discourse on nuclear energy over the last 20 years (1973-1993). The world-views concerning the relationship between nature and society of collective actors in the Federal Republic of Germany were the focus. Starting out from the hypothesis that social movements are ''forces of definition'' in modern society, we analysed the BBU (Federal Association of Citizen Action Groups for Environmental Protection) and the Green Party. These groups have had a strong impact on established environmental organisations in Germany. There is also a clear impact of the ecology movement on parts of the Social Democrats (SPD) and trade unions. The impact on the Liberal and Conservative parties is much weaker. However, these actors as well, integrated ecological world-views into their productionist outlooks. With the help of the Greens, the ecological discourse entered into parliament where it was later supported by factions of the SPD. In the area of the productionist sector of society, trade unions challenged employer associations on the grounds of environmental issues. Yet, the German unification retarded the institutionalisation of ecological standpoints. This concerns the ecological movement as well as established actors. However, it needs to be mentioned that this decay started already in the late 1980s. (orig.) [de

  15. Compression and immersion tests and leaching of radionuclides, stable metals, and chelating agents from cement-solidified decontamination waste collected from nuclear power stations

    Energy Technology Data Exchange (ETDEWEB)

    Akers, D.W.; Kraft, N.C.; Mandler, J.W. [EG and G Idaho, Inc., Idaho Falls, ID (United States)

    1994-06-01

    A study was performed for the Nuclear Regulatory Commission (NRC) to evaluate structural stability and leachability of radionuclides, stable metals, and chelating agents from cement-solidified decontamination ion-exchange resin wastes collected from seven commercial boiling water reactors and one pressurized water reactor. The decontamination methods used at the reactors were the Can-Decon, AP/Citrox, Dow NS-1, and LOMI processes. Samples of untreated resin waste and solidified waste forms were subjected to immersion and compressive strength testing. Some waste-form samples were leach-tested using simulated groundwaters and simulated seawater for comparison with the deionized water tests that are normally performed to assess waste-form leachability. This report presents the results of these tests and assesses the effects of the various decontamination methods, waste form formulations, leachant chemical compositions, and pH of the leachant on the structural stability and leachability of the waste forms. Results indicate that releases from intact and degraded waste forms are similar and that the behavior of some radionuclides such as {sup 55}Fe, {sup 60}Co, and {sup 99}Tc were similar. In addition, the leachability indexes are greater than 6.0, which meets the requirement in the NRC`s ``Technical Position on Waste Form,`` Revision 1.

  16. Concentrations of Radiocesium in Local Foods Collected in Kawauchi Village after the Accident at the Fukushima Dai-ichi Nuclear Power Station

    Science.gov (United States)

    Orita, Makiko; Nakashima, Kanami; Hayashida, Naomi; Endo, Yuuko; Yamashita, Shunichi; Takamura, Noboru

    2016-06-01

    We evaluated the current concentrations of radiocesium in local foods collected in Kawauchi Village, which is located less than 30 km from Fukushima Daiichi Nuclear Power Station, to minimize public anxiety regarding internal radiation exposure through the consumption of locally produced foods after the 2011 Fukushima accident. The number of samples exceeding the regulatory radiocesium limit (100 Bq/kg for general foods) was five out of 4,080 vegetables (0.1%), 652 of 1,986 (32.8%) among edible wild plants and fungi, and eight of 647 (1.2%) in fruits. Our study confirmed that the internal radiation doses of ingesting these foods are acceptably low compared to the public dose limit, ranging from 24.4 to 42.7 μSv for males and from 21.7 to 43.4 μSv for females, although the potential for radiation exposure still exists. Long-term comprehensive follow-up should take place to clarify trends in radiocesium concentrations in local foods and the committed effective doses found in Fukushima-area residents. By constructing a system that allows residents to access information on radiocesium concentration in foods, a risk communication model between specialists and residents could be developed in the recovery phase after the Fukushima accident.

  17. Geological disposal of radioactive waste: national commitment, local and regional involvement - A Collective Statement of the OECD Nuclear Energy Agency Radioactive Waste Management Committee Adopted March 2012

    International Nuclear Information System (INIS)

    2012-01-01

    Disposal in engineered facilities built in stable, deep geological formations is the reference solution for permanently isolating long-lived radioactive waste from the human biosphere. This management method is designed to be intrinsically safe and final, meaning that it is not dependent on human presence or intervention in order to fulfil its safety goal. Selecting the site of a waste repository brings up a range of issues involving scientific knowledge, technical capacity, ethical values, territorial planning, community well-being and more. Bringing to fruition the multi-decade task of siting and developing a repository demands a strong national commitment and significant regional and local involvement. This collective statement by the Radioactive Waste Management Committee of the OECD Nuclear Energy Agency recognises the advances made towards greater transparency and dialogue among the diverse stakeholders concerned and identifies the fundamental elements needed to support national commitment and to foster territorial involvement. It concludes that technical and societal partners can develop shared confidence in the safety of geological repositories and jointly carry these projects forward [fr

  18. The collection of the information on peaceful use of atomic energy and nuclear now proliferation and its summaries and analysis. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sato, S.; Takeda, Hiroshi [PESCO Co. Ltd., Tokyo (Japan)

    1999-03-01

    This report summarizes the monthly topics on peaceful uses of atomic energy and management of nuclear materials and its proliferation. The topics are based on the 127 related articles appeared in the newspapers of Japan; those are the Yomiuri, the Asahi, the Mainichi and the Sankei in ten months from May 1998 to February 1999. The most frequent topics are (1) nuclear inspection of Iraq and suspicion for nuclear weapon, (2) nuclear experiments, economic sanctions and CTBT in India and Pakistan, (3) underground nuclear facilities of North Korea and discussions on KEDO. The United Nations Security Council, IAEA and each country have responded on the issues of nuclear disarmament, nuclear non-proliferation, a resolution on suspension of nuclear test, reinforcement of IAEA security actions and an organization of NPT. The next topic is disarmament talks of nuclear weapon and nuclear waste disposal between USA and Russian Federation. Noteworthy issues are promotion of international cooperation on disposal of dismantled nuclear material of Russian Federation and supports for commercial use of plutonium. The fundamental concept is the timing of the pace between USA and Russian Federation on nuclear weapon disarmament. The point is how to realize the plan in the economical difficulty of Russian Federation. Other topics in the newspapers are disposal of Russian atomic submarines, sub-critical nuclear experiments of USA and Russian Federation, tritium production of USA, commercial uses of highly enriched uranium, nuclear of Iran, missile issues, transportation of plutonium. Technical terms and abbreviations are explained after the monthly topics with its background. The total 127 references of the newspaper articles are attached after the topics. (Y. Tanaka)

  19. Novel Role of Superfluidity in Low-Energy Nuclear Reactions.

    Science.gov (United States)

    Magierski, Piotr; Sekizawa, Kazuyuki; Wlazłowski, Gabriel

    2017-07-28

    We demonstrate, within symmetry unrestricted time-dependent density functional theory, the existence of new effects in low-energy nuclear reactions which originate from superfluidity. The dynamics of the pairing field induces solitonic excitations in the colliding nuclear systems, leading to qualitative changes in the reaction dynamics. The solitonic excitation prevents collective energy dissipation and effectively suppresses the fusion cross section. We demonstrate how the variations of the total kinetic energy of the fragments can be traced back to the energy stored in the superfluid junction of colliding nuclei. Both contact time and scattering angle in noncentral collisions are significantly affected. The modification of the fusion cross section and possibilities for its experimental detection are discussed.

  20. Surveying the nuclear caloric curve

    International Nuclear Information System (INIS)

    Ma, Y.G.; Siwek, A.; Peter, J.; Durand, D.; Gulminelli, F.; Steckmeyer, J.C.; Tamain, B.; Vient, E.; Bacri, Ch.O.; and others.

    1996-01-01

    The dependence of nuclear temperature upon excitation energy is experimentally studied. A study of the relation between isotope temperatures and excitation energy up to 25 MeV per nucleon is presented. The 36 Ar+ 58 Ni system is investigated at 52,74 and 95 MeV/u. (K.A.)

  1. Rated power factor and excitation system of large turbine generator

    International Nuclear Information System (INIS)

    Tokumitsu, Iwao; Watanabe, Takashi; Banjou, Minoru.

    1979-01-01

    As for the rated power factor of turbine generators for thermal power stations, 90% has been adopted since around 1960. On the other hand, power transmission system has entered 500 kV age, and 1,000 kV transmission is expected in the near future. As for the supply of reactive power from thermal and nuclear turbine generators, the necessity of supplying leading reactive power has rather increased. Now, the operating power factor of thermal and nuclear generators becomes 96 to 100% actually. As for the excess stability of turbine generators owing to the strengthening of transmission system and the adoption of super-high voltage, the demand of strict conditions can be dealt with by the adoption of super-fast response excitation system of thyristor shunt winding self exciting type. The adoption of the turbine generators with 90 to 95% power factor and the adoption of the thyristor shunt winding self exciting system were examined and evaluated. The rated power factor of generators, excitation system and economy of adopting these systems are explained. When the power factor of generators is increased from 0.9 to 0.95, about 6% of saving can be obtained in the installation cost. When the thyristor shunt winding self excitation is adopted, it is about 10% more economical than AC excitation. (Kako, I.)

  2. Nuclear spectroscopy with fast exotic beams

    International Nuclear Information System (INIS)

    Gade, Alexandra

    2013-01-01

    The often surprising properties of neutron-rich nuclei have prompted extensive experimental and theoretical studies aimed at identifying the driving forces behind the dramatic changes encountered in the exotic regime. Challenging discovery experiments that search for new isotopes in the quest to delineate the limits of nuclear existence provide fundamental benchmarks for nuclear theory, addressing the question what combinations of protons and neutrons can be made into nuclei. As will be discussed here, the existence of certain nuclear species and their production cross sections can provide a first glimpse at nuclear structure effects in the most exotic regime. Striving for more detail on the evolution of nuclear structure, in-beam nuclear spectroscopy with fast beams and thick reaction targets—where γ-ray spectroscopy is used to tag the final state—provides information on the single-particle structure as well as on collective degrees of freedom in nuclei that are available for experiments at beam rates of only a few ions/s. This article will outline—with the example of shell evolution along the N = 40 isotone line—how in-beam experiments measure complementary observables, starting from the nuclear existence and production cross sections to the collective and single-particle properties of the lowest-lying excited states in the vicinity of the very neutron-rich Ti, Cr and Fe N = 40 isotones. The interplay of experimental results and theory will be emphasized at the intersection of nuclear structure and reactions in the joined quest of unraveling the driving forces of shell evolution. (paper)

  3. Halo nuclei: Spectroscopy of excited levels by means of Coulomb excitation and development of an original technique for measurement of fragmentation excitation functions

    International Nuclear Information System (INIS)

    Corre, J.M.

    1994-01-01

    This thesis presents the study of halo nuclei (whose last nucleons are weakly bound and able to move far from the core) in two different and original ways: the first one is a search of bound excited levels by means of Coulomb excitation of medium energy radioactive beams. After a brief recall of classical and relativistic Coulomb excitation theory (Winther and Alder's model), we describe experimental set-up. We used Doppler effect as a signature of the de-excitation of the projectile. The data analysis shows that we populated the excited state E1 of 11 Be nucleus with the cross-section rather different from theoretical value. Different explanations are possible: -destructive Coulomb-nuclear interferences; - an excitation followed by the dissociation of the projectile. This is for the first time that such a result is obtained for radioactive beams at high energy: it shows that Coulomb excitation is a reliable method for the spectroscopy of halo nuclei. In the case of the other studied nuclei 12,14 Be and 8 He, we havn't found excited bound state: upper limits for E1 transition probabilities are given. The second part of this report presents an original technique allowing the measurement of fragmentation excitation function with a beam at fixed energy: it is suitable to study dissociation of weakly bound nuclei. The technique uses a telescope of silicon detectors which plays in the same time the role of target, slowing down material and effective detector. The method used for both reactions (triton, deuteron) and 8 B, 7 Be plus proton proved to be of limited use in the low energy domain due to experimental conditions. However, even if these difficulties are overcome, it seems very difficult to reach the Coulomb barrier domain with our method. (orig.)

  4. Local Control Theory in Trajectory Surface Hopping Dynamics Applied to the Excited-State Proton Transfer of 4-Hydroxyacridine.

    Science.gov (United States)

    Curchod, Basile F E; Penfold, Thomas J; Rothlisberger, Ursula; Tavernelli, Ivano

    2015-07-20

    The application of local control theory combined with nonadiabatic ab initio molecular dynamics to study the photoinduced intramolecular proton transfer reaction in 4-hydroxyacridine was investigated. All calculations were performed within the framework of linear-response time-dependent density functional theory. The computed pulses revealed important information about the underlying excited-state nuclear dynamics highlighting the involvement of collective vibrational modes that would normally be neglected in a study performed on model systems constrained to a subset of the full configuration space. This study emphasizes the strengths of local control theory for the design of pulses that can trigger chemical reactions associated with the population of a given molecular excited state. In addition, analysis of the generated pulses can help to shed new light on the photophysics and photochemistry of complex molecular systems. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Excitation and Transmitted Torque

    Directory of Open Access Journals (Sweden)

    H. B. H. Gubran

    2000-01-01

    Full Text Available In the present study, stress analysis of fiber reinforced thin composite shafts subjected to unbalance excitation and steady torque, is carried out. Shafts of uniform as well as variable wall thickness are considered. The shaft is modeled as a simply supported Timoshenko beam in which shear deformation, rotary inertia and gyroscopic effects have been included. Modified equivalent modulus beam theory has been adopted. Rayleigh-Ritz displacements are used for deriving the solution equations. Shafts with a uniform wall thickness, and with variable wall thickness in which the thickness is varied along the axial length of the shaft for three different cases of fiber angles have been studied. Axial variation of stresses is studied in detail. Results obtained indicate that the stresses in the variable wall thickness are smaller than the one with uniform wall thickness, even for the same weight of the shaft.

  6. CINE: Comet INfrared Excitation

    Science.gov (United States)

    de Val-Borro, Miguel; Cordiner, Martin A.; Milam, Stefanie N.; Charnley, Steven B.

    2017-08-01

    CINE calculates infrared pumping efficiencies that can be applied to the most common molecules found in cometary comae such as water, hydrogen cyanide or methanol. One of the main mechanisms for molecular excitation in comets is the fluorescence by the solar radiation followed by radiative decay to the ground vibrational state. This command-line tool calculates the effective pumping rates for rotational levels in the ground vibrational state scaled by the heliocentric distance of the comet. Fluorescence coefficients are useful for modeling rotational emission lines observed in cometary spectra at sub-millimeter wavelengths. Combined with computational methods to solve the radiative transfer equations based, e.g., on the Monte Carlo algorithm, this model can retrieve production rates and rotational temperatures from the observed emission spectrum.

  7. Length of excitable knots

    Science.gov (United States)

    Maucher, Fabian; Sutcliffe, Paul

    2017-07-01

    In this paper, we present extensive numerical simulations of an excitable medium to study the long-term dynamics of knotted vortex strings for all torus knots up to crossing number 11. We demonstrate that FitzHugh-Nagumo evolution preserves the knot topology for all the examples presented, thereby providing a field theory approach to the study of knots. Furthermore, the evolution yields a well-defined minimal length for each knot that is comparable to the ropelength of ideal knots. We highlight the role of the medium boundary in stabilizing the length of the knot and discuss the implications beyond torus knots. We also show that there is not a unique attractor within a given knot topology.

  8. Monopole excitation of nucleus in the bound muon decay

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  9. Nuclear hadrodynamics

    International Nuclear Information System (INIS)

    Geesaman, D.F.

    1984-01-01

    The role of hadron dynamics in the nucleus is illustrated to show the importance of nuclear medium effects in hadron interactions. The low lying hadron spectrum is considered to provide the natural collective variables for nuclear systems. Recent studies of nucleon-nucleon and delta-nucleon interactions are reviewed, with emphasis on the type of experimental phenomena which signal the importance of the many-body dynamics. 28 references

  10. Liquid storage tanks under seismic excitations

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Yu; Uras, R.A.; Chang, Yao W.

    1993-08-01

    The safety and reliable performance of nuclear power plants is of great concern to both the nuclear community and the general public. A nuclear power plant has to be designed to withstand any earthquakes that may occur at its location. Since a nuclear power plant has many liquid storage tanks, the dynamic response of these tanks under seismic excitations must properly analyzed in order to design these tanks to survive the earthquakes to which they may be subjected. The dynamic response of liquid-storage tanks subjected to ground excitations has been the subject of numerous studies in the past thirty years. However, most of the studies were focused on the responses of the tanks such that the contained liquid can be considered to be incompressible and inviscid. Thus, the effect of liquid viscosity on the dynamic response of the liquid-tank system is often ignored. This is justified for water-storage tanks because water has a very small viscosity. However, there are cases where the liquid viscosity is not small in comparison with that of water. For such cases the designs of these tanks based on the inviscid assumption become questionable, and the effect of viscosity on the dynamic response needs to be assessed. To the best of our knowledge, due to the complexity of the problem, the effect of viscosity has not been studied satisfactorily to date. Since the governing equations are very complicated if viscosity is included in the analysis, the closed form solutions in most cases are unattainable. Therefore, it is necessary to use a computer code to solve the equations-numerically. The computer code used in this study is the finite element code, FLUSTR-ANL(FLUid-STRucture interaction code developed at Argonne National Laboratory) (Chang et al.1988). In this study, the tanks are assumed to be rigid and rigidly supported on their bases, and the responses are considered to be linear.

  11. Analysis and relevant treatment of diametral tolerance of exciter shaft in unit 2

    International Nuclear Information System (INIS)

    Liu Qiang

    2012-01-01

    The generator and exciter unit has three support in Qinshan Nuclear Power Plant Phase Ⅱ, there are two bearings for the generator rotor and one for the exciter, this structure results in that it is difficult to achieve the standard when checking the exciter bearing's diametral tolerance. In the fifth outage of unit 2 in Qinshan Nuclear Power Plant Phase Ⅱ, the diametral tolerance failed to achieve the standard, there were several reasons for this, such as the alignment of generator and exciter coupling, the angular moment of generator and exciter coupling bolt. the end surface condition of generator and exciter coupling, the fitting dimension of the coupling bolt hole and the sleeve in it. After the analysis of all reasons one by one, it was confirmed that the radical reason was the abnormal condition of the generator coupling end surface, the problem was solved by machining it. (author)

  12. Observation of low- and high-energy Gamow-Teller phonon excitations in nuclei.

    Science.gov (United States)

    Fujita, Y; Fujita, H; Adachi, T; Bai, C L; Algora, A; Berg, G P A; von Brentano, P; Colò, G; Csatlós, M; Deaven, J M; Estevez-Aguado, E; Fransen, C; De Frenne, D; Fujita, K; Ganioğlu, E; Guess, C J; Gulyás, J; Hatanaka, K; Hirota, K; Honma, M; Ishikawa, D; Jacobs, E; Krasznahorkay, A; Matsubara, H; Matsuyanagi, K; Meharchand, R; Molina, F; Muto, K; Nakanishi, K; Negret, A; Okamura, H; Ong, H J; Otsuka, T; Pietralla, N; Perdikakis, G; Popescu, L; Rubio, B; Sagawa, H; Sarriguren, P; Scholl, C; Shimbara, Y; Shimizu, Y; Susoy, G; Suzuki, T; Tameshige, Y; Tamii, A; Thies, J H; Uchida, M; Wakasa, T; Yosoi, M; Zegers, R G T; Zell, K O; Zenihiro, J

    2014-03-21

    Gamow-Teller (GT) transitions in atomic nuclei are sensitive to both nuclear shell structure and effective residual interactions. The nuclear GT excitations were studied for the mass number A = 42, 46, 50, and 54 "f-shell" nuclei in ((3)He, t) charge-exchange reactions. In the (42)Ca → (42)Sc reaction, most of the GT strength is concentrated in the lowest excited state at 0.6 MeV, suggesting the existence of a low-energy GT phonon excitation. As A increases, a high-energy GT phonon excitation develops in the 6-11 MeV region. In the (54)Fe → (54)Co reaction, the high-energy GT phonon excitation mainly carries the GT strength. The existence of these two GT phonon excitations are attributed to the 2 fermionic degrees of freedom in nuclei.

  13. NRC collection of abbreviations

    International Nuclear Information System (INIS)

    1992-03-01

    The US Nuclear Regulatory Commission (NRC) staff collected this list of abbreviations from NRC documents and nuclear industry documents, both foreign and domestic. Readers can use the collection, which is not all inclusive, to identify the terms from which the abbreviations are formed. The Editorial Section of the Division of Freedom of Information and Publications Services compiled this collection. In the introduction, the editorial staff offers suggestions for using abbreviations but does not recommend the use of one abbreviation over another

  14. Subsurface excitations in a metal

    DEFF Research Database (Denmark)

    Ray, M. P.; Lake, R. E.; Sosolik, C. E.

    2009-01-01

    We investigate internal hot carrier excitations in a Au thin film bombarded by hyperthermal and low energy alkali and noble gas ions. Excitations within the thin film of a metal-oxide-semiconductor device are measured revealing that ions whose velocities fall below the classical threshold given...... by the free-electron model of a metal still excite hot carriers. Excellent agreement between these results and a nonadiabatic model that accounts for the time-varying ion-surface interaction indicates that the measured excitations are due to semilocalized electrons near the metal surface....

  15. Radiocesium concentrations in the bark, sapwood and heartwood of three tree species collected at Fukushima forests half a year after the Fukushima Dai-ichi nuclear accident.

    Science.gov (United States)

    Kuroda, Katsushi; Kagawa, Akira; Tonosaki, Mario

    2013-08-01

    Radiocesium ((134)Cs and (137)Cs) distribution in tree stems of Japanese cedar (aged 40-56 y), red pine (42 y), and oak (42 y) grown in Fukushima Prefecture were investigated approximately half a year after the Fukushima Dai-ichi nuclear accident. Japanese cedar, red pine, and oak were selected from five sites, one site, and one site, respectively. Three trees at each site were felled, and bark, sapwood (the outer layer of wood in the stem), and heartwood (the inner layer of wood in the stem) separately collected to study radiocesium concentrations measured by gamma-ray spectrometry. The radiocesium deposition densities at the five sites were within the range of 16-1020 kBq m(-2). The radiocesium was distributed in bark, sapwood, and heartwood in three tree species, indicating that very rapid translocation of radiocesium into the wood. The concentration of radiocesium in oak (deciduous angiosperm) bark was higher than that in the bark of Japanese cedar and red pine (evergreen gymnosperms). Both sapwood and heartwood contained radiocesium, and the values were much lower than that in the bark samples. The results suggest that radiocesium contamination half a year after the accident was mainly attributable to the direct radioactive deposition. The radiocesium concentrations in the Japanese cedar samples taken from five sites rose with the density of radiocesium accumulation on the ground surface. To predict the future dynamics of radiocesium in tree stems, the present results taken half a year after the accident are important, and continuous study of radiocesium in tree stems is necessary. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Z-dependence of Mean Excitation Energies for Second and Third Row Atoms and Their Ions

    DEFF Research Database (Denmark)

    Sauer, Stephan P. A.; Sabin, John R.; Oddershede, Jens

    2018-01-01

    All mean excitations energies for second and third row atoms and their ions are calculated in the random‐phase approximation using large basis sets. To a very good approximation it turns out that mean excitation energies within an isoelectronic series is a quadratic function of the nuclear charge...

  17. Nucleon Isovector Pairing in Nuclei: Microscopic Approach, Boson Representation, and Collective Model

    Science.gov (United States)

    Jolos, R. V.; Kartavenko, V. G.; Kolganova, E. A.

    2018-03-01

    Nucleon pair correlations in atomic nuclei are analyzed within a nuclear microscopic model with residual isovector pairing forces. These are formulated in the boson representation of fermion operators whereby the collective mode of pair excitations can be isolated without restricting the size of the one-particle basis. This method allows one to analyze the fluctuations in the nonsuperfluid phase of nuclear matter, its phase transition to the superfluid phase, and strong pair correlations. The performance of the method is exemplified by numerical results for the nuclei in the vicinity of the doubly magic 56Ni nucleus.

  18. Proceedings of the 9. Workshop on Nuclear Physics - Communications of basic nuclear physics

    International Nuclear Information System (INIS)

    1986-01-01

    The abstracts of researches on basic nuclear physics of 9. Workshop on Nuclear Physics in Brazil are presented. Mathematical models and experimental methods for nuclear phenomenon description, such as nuclear excitation and disintegration of several nuclei were discussed. (M.C.K.) [pt

  19. The giant quadrupole resonance in highly excited rotating nuclei

    International Nuclear Information System (INIS)

    Civitarese, O.; Furui, S.; Ploszajczak, M.; Faessler, A.

    1983-01-01

    The giant quadrupole resonance in highly excited, fast rotating nuclei is studied as a function of both the nuclear temperature and the nuclear angular momentum. The photo-absorption cross sections for quadrupole radiation in 156 Dy, 160 Er and 164 Er are evaluated within the linear response theory. The strength functions of the γ-ray spectrum obtained from the decay of highly excited nuclear states by deexcitation of the isoscalar quadrupole mode show a fine structure, which depends on the temperature T, the angular momentum I and the deformation of the nucleus β. The splitting of the modes associated with the signature-conserving and signature-changing components of the quadrupole field is discussed. (orig.)

  20. Emergence of Asynchronous Local Clocks in Excitable Media.

    Science.gov (United States)

    Gerum, Richard Carl; Fabry, Ben; Metzner, Claus

    2015-01-01

    Excitable media such as the myocardium or the brain consist of arrays of coupled excitable elements, in which the local excitation of a single element can propagate to its neighbors in the form of a non-linear autowave. Since each element has to pass through a refractory period immediately after excitation, the frequency of autowaves is self-limiting. In this work, we consider the case where each element is spontaneously excited at a fixed average rate and thereby initiates a new autowave. Although these spontaneous self-excitation events are modelled as independent Poisson point processes with exponentially distributed waiting times, the travelling autowaves lead collectively to a non-exponential, unimodal waiting time distribution for the individual elements. With increasing system size, a global 'clock' period T emerges as the most probable waiting time for each element, which fluctuates around T with an increasingly small but non-zero variance. This apparent synchronization between asynchronous, temporally uncorrelated point processes differs from synchronization effects between perfect oscillators interacting in a phase-aligning manner. Finally, we demonstrate that asynchronous local clocks also emerge in non-homogeneous systems in which the rates of self-excitation are different for all individuals, suggesting that this novel mechanism can occur in a wide range of excitable media.

  1. Topological excitations in magnetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D., E-mail: bazeia@fisica.ufpb.br [Departamento de Física, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB (Brazil); Doria, M.M. [Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro (Brazil); Dipartimento di Fisica, Università di Camerino, I-62032 Camerino (Italy); Rodrigues, E.I.B. [Departamento de Física, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB (Brazil)

    2016-05-20

    In this work we propose a new route to describe topological excitations in magnetic systems through a single real scalar field. We show here that spherically symmetric structures in two spatial dimensions, which map helical excitations in magnetic materials, admit this formulation and can be used to model skyrmion-like structures in magnetic materials.

  2. Nuclear data newsletter. No. 26

    International Nuclear Information System (INIS)

    1998-10-01

    This issue announces the online and offline news concerning nuclear data cross section libraries and data processing codes available from Nuclear Data Section (NDS) of IAEA. In includes announcements on development activities of IAEA in the field of nuclear data collections and relevant computer codes and lists selected reports and documents on nuclear data as well as cooperating nuclear data service centres

  3. Nuclear data newsletter. No. 27

    International Nuclear Information System (INIS)

    1999-03-01

    This issue announces the online and offline news concerning nuclear data cross section libraries and data processing codes available from Nuclear Data Section (NDS) of IAEA. In includes announcements on development activities of IAEA in the field of nuclear data collections and relevant computer codes and lists selected reports and documents on nuclear data as well as cooperating nuclear data service centres

  4. Nuclear data newsletter. No. 32

    International Nuclear Information System (INIS)

    2001-09-01

    This issue announces the online and offline news concerning nuclear data cross section libraries and data processing codes available from Nuclear Data Section (NDS) of IAEA. It includes announcements on development activities of IAEA in the field of nuclear data collections and relevant computer codes and lists selected reports and documents on nuclear data as well as cooperating nuclear data service centres

  5. Nuclear data newsletter. No. 29

    International Nuclear Information System (INIS)

    2000-04-01

    This issue announces the online and offline news concerning nuclear data cross section libraries and data processing codes available from Nuclear Data Section (NDS) of IAEA. In includes announcements on development activities of IAEA in the field of nuclear data collections and relevant computer codes and lists selected reports and documents on nuclear data as well as cooperating nuclear data service centres

  6. Nuclear data newsletter. No. 28

    International Nuclear Information System (INIS)

    1999-10-01

    This issue announces the online and offline news concerning nuclear data cross section libraries and data processing codes available from Nuclear Data Section (NDS) of IAEA. In includes announcements on development activities of IAEA in the field of nuclear data collections and relevant computer codes and lists selected reports and documents on nuclear data as well as cooperating nuclear data service centres

  7. Coulomb excitation at shell-closure N = 40

    International Nuclear Information System (INIS)

    Leenhardt, S.; Azaiez, F.; Sorlin, O.

    1999-01-01

    The structure of exotic nuclei can be investigated by Coulomb excitation of radioactive beams. The value of the energy of the first 2 + and its excitation probability B(E2) can improve our knowledge about collective modes of even-even nuclei. The search of new regions of deformation and shape coexistence is also a strong motivation. Recent experiments have been performed with GANIL/LISE3 facility, using the detector 'Chateau de Cristal'. (authors)

  8. Intrinsic excitations in deformed nuclei: characteristic predictions of the IBA

    International Nuclear Information System (INIS)

    Casten, R.F.

    1982-01-01

    Deformed nuclei represent perhaps the largest and best studied class of nuclear level schemes. The Interacting Boson Approximation (IBA) model is devised so as to provide a general framework for the description of low lying collective states in nuclei spanning vibrational, rotational (i.e., deformed) and axially asymmetric types as well as the transitional species intermediate between these limiting cases. The juxtaposition of these two statements makes it all the more surprising that until recently there had been no thorough test of the model in such nuclei. Partly, the explanation for this lies in the type of data required for an adequate test. Since the IBA predicts a broad range of collective states it requires a correspondingly thorough empirical test. Moreover, in deformed nuclei, though the characteristic predictions that distinguish the IBA from the traditional, familiar collective model of harmonic β and γ vibrations are important, their clearest manifestation occurs in very weak, hard-to-detect low energy transitions between excited vibrational bands (in particular between β and γ bands), that had not heretofore been systematically observed. The present brief summary will begin with a review of the properties of the (n,γ) reaction that render it a useful empirical tool for such studies, and follow this with a description of the results of the 168 Er study and the application of the IBA model to the resultant level scheme. The discussion will then be generalized to other deformed nuclei and to the inherent systematic predictions that must characterize the IBA for such nuclei. Many of these ideas will be related to the role of finite boson number in the IBA

  9. Isospin effects in nuclear vibrations

    International Nuclear Information System (INIS)

    Madsen, V.A.; Brown, V.R.

    1984-09-01

    A review of the evidence that the ratio of neutron and proton multipole matrix elements for collective vibrations in single-closed-shell nuclei differ systematically from N/Z is presented. A theoretical framework is given for understanding the data on the basis of the ideas of core polarization. It follows that nuclear deformation parameters are probe dependent and that analysis of excitations by two different probes such as (p,p') and (n,n') can, in principle, give the ratio M/sub n//M/sub p/. Application is made to first 2 + states of open shell nuclei. Trends of M/sub n//M/sub p/ for higher 2 + states are presented. Expected systematics of M/sub n//M/sub p/ ratios for giant isoscalar quadrupole transitions are presented. 22 references

  10. Nuclear Information and Knowledge, News from the Nuclear Information Section, No. 14, June 2013

    International Nuclear Information System (INIS)

    2013-06-01

    A Google search for 'nuclear information' places INIS on the first page of the results. In fact, it is ranked second of all search hits. This great result was achieved through hard work collecting world nuclear documentation for more than 40 years. INIS achieved this admirable place through a tremendous amount of joint effort and work, but in order to remain there, constant improvements and changes are necessary. This issue of the Nuclear Information and Knowledge Newsletter talks about some of those changes and the work done by the Nuclear Information Section during the last months.A great number of records were added to the INIS Collection. This and other achievements are described in the article on INIS. The main INIS input tool, FIBRE+, has undergone modifications, adding new features. The article on the history of digital preservation at INIS describes the ways and means for digitizing and making available hundreds of thousands of full texts. Some of the most exciting changes are happening with the INIS Collection Search (ICS). Its improved usability, enhanced search results, emailing and quick browsing are some of the features described here

  11. Evolution of nuclear spectroscopy at Saha Institute of Nuclear Physics

    Indian Academy of Sciences (India)

    Abstract. Experimental studies of nuclear excitations have been an important subject from the ear- liest days when the institute was established. The construction of 4 MeV proton cyclotron was mainly aimed to achieve this goal. Early experiments in nuclear spectroscopy were done with radioactive nuclei with the help of ...

  12. Get excited: reappraising pre-performance anxiety as excitement.

    Science.gov (United States)

    Brooks, Alison Wood

    2014-06-01

    Individuals often feel anxious in anticipation of tasks such as speaking in public or meeting with a boss. I find that an overwhelming majority of people believe trying to calm down is the best way to cope with pre-performance anxiety. However, across several studies involving karaoke singing, public speaking, and math performance, I investigate an alternative strategy: reappraising anxiety as excitement. Compared with those who attempt to calm down, individuals who reappraise their anxious arousal as excitement feel more excited and perform better. Individuals can reappraise anxiety as excitement using minimal strategies such as self-talk (e.g., saying "I am excited" out loud) or simple messages (e.g., "get excited"), which lead them to feel more excited, adopt an opportunity mind-set (as opposed to a threat mind-set), and improve their subsequent performance. These findings suggest the importance of arousal congruency during the emotional reappraisal process. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  13. Book of abstracts of International Conference on Nuclear Structure and Dynamics 2009

    International Nuclear Information System (INIS)

    Prepolec, L.; Niksic, T.

    2009-01-01

    Following the long tradition of nuclear physics conferences organized by our two institutes, e.g. the Adriatic International Conference and Europhysics Study Conferences, this meeting will provide a broad discussion forum on recent experimental and theoretical advances in the physics of nuclear structure and reactions. The main focus will be on the following topics: Nuclear structure and reactions far from stability; Exotic modes of excitation and decays; Collective phenomena and symmetries; Ab initio, cluster model, and shell-model approaches; Nuclear energy density functionals; Heavy-ion reactions at near-barrier energies; Dynamics of light-ion reactions; Nuclear reactions of astrophysical interest; Weak-interaction processes. This booklet contains the abstracts of contributions which will be presented at the Conference, either as invited and contributed talks, or oral poster presentations

  14. Excitation-energy influence at the scission configuration

    Directory of Open Access Journals (Sweden)

    Ramos D.

    2017-01-01

    Full Text Available Transfer- and fusion-induced fission in inverse kinematics was proven to be a powerful tool to investigate nuclear fission, widening the information of the fission fragments and the access to unstable fissioning systems with respect to other experimental approaches. An experimental campaign for fission investigation has being carried out at GANIL with this technique since 2008. In these experiments, a beam of 238U, accelerated to 6.1 MeV/u, impinges on a 12C target. Fissioning systems from U to Cf are populated through transfer and fusion reactions, with excitation energies that range from few MeV up to 46 MeV. The use of inverse kinematics, the SPIDER telescope, and the VAMOS spectrometer permitted the characterization of the fissioning system in terms of mass, nuclear charge, and excitation energy, and the isotopic identification of the full fragment distribution. The neutron excess, the total neutron multiplicity, and the even-odd staggering in the nuclear charge of fission fragments are presented as a function of the excitation energy of the fissioning system. Structure effects are observed at Z∼50 and Z∼55, where their impact evolves with the excitation energy.

  15. Limiting Temperatures for Collective Motion: The Giant Dipole Resonance in Very Hot Nuclei

    Science.gov (United States)

    Piattelli, P.; Blumenfeld, Y.; Le Faou, J. H.; Suomijärvi, T.; Agodi, C.; Alamanos, N.; Alba, R.; Auger, F.; Bellia, G.; Chomaz, Ph.; Coniglione, R.; Del Zoppo, A.; Finocchiaro, P.; Frascaria, N.; Gaardhøje, J. J.; Garron, J. P.; Gillibert, A.; Lamehi-Rachti, M.; Liguori-Neto, R.; Loukachine, K.; Maiolino, C.; Migneco, E.; Roynette, J. C.; Santonocito, D.; Sapienza, P.; Scarpaci, J. A.

    1996-02-01

    The study of the Giant Dipole Resonance (GDR) excited in hot nuclei allows to follow the evolution of collective motion with increasing nuclear temperature. A brief review of the characteristics of the GDR excited in nuclei with excitation energies up to ˜ 500 MeV is given. The results of recent experiments in which very hot nuclei have been studied with a nearly 4π detector are presented. Gamma-rays, light charged particles and evaporation residues emitted from hot nuclei of mass around 115 and excitation energies above 300 MeV, formed in the 36Ar + 90Zr at 27 MeV/u and 36Ar + 98Mo at 37 MeV/u reactions, have been measured with the MEDEA multidetector. The γ-ray yield from the decay of the Giant Dipole Resonance in these nuclei has been found to be independent of excitation energy and bombarding energy. The measured γ-ray spectra are compared with statistical calculations encompassing several recent theoretical models for the quenching of gamma-ray emission from the dipole resonance at very high temperatures. The best agreement with the data is obtained by assuming a cut-off of the resonance γ-emission above an excitation energy of 250 MeV.

  16. Microcanonical simulation of nuclear multifragmentation

    International Nuclear Information System (INIS)

    Randrup, J.; Koonin, S.E.

    1987-01-01

    We discuss the formal basis for the theoretical treatment of nuclear multifragmentation within a microcanonical framework. The important role played by highly excited nuclear states and the interfragment forces is illustrated. The requirement of detailed balance is especially discussed and illustrated for the fission-fusion Metropolis moves in configuration space. 13 refs., 2 figs

  17. Gravitational waves from neutron star excitations in a binary inspiral

    Science.gov (United States)

    Parisi, Alessandro; Sturani, Riccardo

    2018-02-01

    In the context of a binary inspiral of mixed neutron star-black hole systems, we investigate the excitation of the neutron star oscillation modes by the orbital motion. We study generic eccentric orbits and show that tidal interaction can excite the f -mode oscillations of the star by computing the amount of energy and angular momentum deposited into the star by the orbital motion tidal forces via closed form analytic expressions. We study the f -mode oscillations of cold neutron stars using recent microscopic nuclear equations of state, and we compute their imprint into the emitted gravitational waves.

  18. Excited cooper pairs

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Arrietea, M. G.; Solis, M. A.; De Llano, M. [Universidad Nacional Autonoma de Mexico, Mexico, D.F (Mexico)

    2001-02-01

    Excited cooper pairs formed in a many-fermion system are those with nonzero total center-of mass momentum (CMM). They are normally neglected in the standard Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity for being too few compared with zero CMM pairs. However, a Bose-Einstein condensation picture requires both zero and nonzero CMM pairs. Assuming a BCS model interaction between fermions we determine the populations for all CMM values of Cooper pairs by actually calculating the number of nonzero-CMM pairs relative to that of zero-CMM ones in both 2D and 3D. Although this ratio decreases rapidly with CMM, the number of Cooper pairs for any specific CMM less than the maximum (or breakup of the pair) momentum turns out to be typically larger than about 95% of those with zero-CMM at zero temperature T. Even at T {approx}100 K this fraction en 2D is still as large as about 70% for typical quasi-2D cuprate superconductor parameters. [Spanish] Los pares de cooper excitados formados en un sistema de muchos electrones, son aquellos con momentos de centro de masa (CMM) diferente de cero. Normalmente estos no son tomados en cuenta en la teoria estandar de la superconductividad de Bardeen-Cooper-Schrieffer (BCS) al suponer que su numero es muy pequeno comparados con los pares de centro de masa igual a cero. Sin embargo, un esquema de condensacion Bose-Einstein requiere de ambos pares, con CMM cero y diferente de cero. Asumiendo una interaccion modelo BCS entre los fermiones, determinamos la poblacion de pares cooper con cada uno de todos los posibles valores del CMM calculando el numero de pares con momentos de centro de masa diferente de cero relativo a los pares de CMM igual a cero, en 2D y 3D. Aunque esta razon decrece rapidamente con el CMM, el numero de pares de cooper para cualquier CMM especifico menor que el momento maximo (o rompimiento de par) es tipicamente mas grande que el 95% de aquellos con CMM cero. Aun a T {approx}100 K esta fraccion en 2D es

  19. State-selective high-energy excitation of nuclei by resonant positron annihilation

    Directory of Open Access Journals (Sweden)

    Nikolay A. Belov

    2015-02-01

    Full Text Available In the annihilation of a positron with a bound atomic electron, the virtual γ photon created may excite the atomic nucleus. We put forward this effect as a spectroscopic tool for an energy-selective excitation of nuclear transitions. This scheme can efficiently populate nuclear levels of arbitrary multipolarities in the MeV regime, including giant resonances and monopole transitions. In certain cases, it may have higher cross sections than the conventionally used Coulomb excitation and it can even occur with high probability when the latter is energetically forbidden.

  20. Uniform excitations in magnetic nanoparticles

    DEFF Research Database (Denmark)

    Mørup, Steen; Frandsen, Cathrine; Hansen, Mikkel Fougt

    2010-01-01

    and the magnetic hyperfine field, in contrast to the Bloch T3/2 law in bulk materials. The temperature dependence of the average magnetization is conveniently studied by Mössbauer spectroscopy. The energy of the uniform excitations of magnetic nanoparticles can be studied by inelastic neutron scattering.......We present a short review of the magnetic excitations in nanoparticles below the superparamagnetic blocking temperature. In this temperature regime, the magnetic dynamics in nanoparticles is dominated by uniform excitations, and this leads to a linear temperature dependence of the magnetization...

  1. Excited states in biological systems

    International Nuclear Information System (INIS)

    Cilento, G.; Zinner, K.; Bechara, E.J.H.; Duran, N.; Baptista, R.C. de; Shimizu, Y.; Augusto, O.; Faljoni-Alario, A.; Vidigal, C.C.C.; Oliveira, O.M.M.F.; Haun, M.

    1979-01-01

    Some aspects of bioluminescence related to bioenergetics are discussed: 1. chemical generation of excited species, by means of two general processes: electron transference and cyclic - and linear peroxide cleavage; 2. biological systems capable of generating excited states and 3. biological functions of these states, specially the non-emissive ones (tripletes). The production and the role of non-emissive excited states in biological systems are analysed, the main purpose of the study being the search for non-emissive states. Experiences carried out in biological systems are described; results and conclusions are given. (M.A.) [pt

  2. Nuclear law - Nuclear safety

    International Nuclear Information System (INIS)

    Pontier, Jean-Marie; Roux, Emmanuel; Leger, Marc; Deguergue, Maryse; Vallar, Christian; Pissaloux, Jean-Luc; Bernie-Boissard, Catherine; Thireau, Veronique; Takahashi, Nobuyuki; Spencer, Mary; Zhang, Li; Park, Kyun Sung; Artus, J.C.

    2012-01-01

    This book contains the contributions presented during a one-day seminar. The authors propose a framework for a legal approach to nuclear safety, a discussion of the 2009/71/EURATOM directive which establishes a European framework for nuclear safety in nuclear installations, a comment on nuclear safety and environmental governance, a discussion of the relationship between citizenship and nuclear, some thoughts about the Nuclear Safety Authority, an overview of the situation regarding the safety in nuclear waste burying, a comment on the Nome law with respect to electricity price and nuclear safety, a comment on the legal consequences of the Fukushima accident on nuclear safety in the Japanese law, a presentation of the USA nuclear regulation, an overview of nuclear safety in China, and a discussion of nuclear safety in the medical sector

  3. Picosecond excitation transport in disordered systems

    International Nuclear Information System (INIS)

    Hart, D.E.

    1987-11-01

    Time-resolved fluorescence decay profiles are used to study excitation transport in 2- and 3-dimensional disordered systems. Time-correlated single photon counting detection is used to collect the fluorescence depolarization data. The high signal-to-noise ratios afforded by this technique makes it possible to critically examine current theories of excitation transport. Care has been taken to eliminate or account for the experimental artifacts common to this type of study. Solutions of 3,3'-diethyloxadicarbocyanine iodide (DODCI) in glycerol serve as a radomly distributed array of energy donors in 3-dimensions. A very thin sample cell (/approximately/ 2 μm) is used to minimize the effects of fluorescence self-absorption on the decay kinetics. Evidence of a dynamic shift of the fluorescence spectrum of DODCI in glycerol due to solvent reorganization is presented. The effects of excitation trapping on the decay profiles is minimized in the data analysis procedure. The 3-body theory of Gochanour, Andersen, and Fayer (GAF) and the far less complex 2-particle analytic theory of Huber, Hamilton, and Barnett yield indistinguishable fits to the data over the wide dynamic range of concentrations and decay times studied

  4. Odd-even effect dependence on the excitation energy in low energy fission

    Science.gov (United States)

    Mirea, M.

    2017-09-01

    An inversion of the odd-even effect was observed experimentally in cold fission: the odd-odd fragmentation yields are favored over the even-even ones for excitations energies of the fragments smaller than 4 MeV. This effect is linked to the important problem of quasiparticle excitations during the dynamical evolution of the nuclear system from its ground-state configuration up to scission. An explanation based on the Landau-Zener promotion mechanism generalized for superfluid systems is offered for the inversion of the odd-even effect. In principle, the even-even fission products cannot be produced at very low excitation energies due dynamical quasiparticle excitations produced in the avoided- level-crossing regions. These excitations are produced with a large probability when the nuclear system deforms slowly.

  5. Source characterization of selected North Caspian events from the relative excitation of regional phases. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Niazi, M.

    1981-11-01

    Seismograms of seven recent events (presumed underground nuclear explosions) which occurred during 1976-1979 in the North Caspian Sea region of the western Soviet Kazakh are compared at regional distances for their relative source excitation characteristics. The body wave magnitude estimates of these events range from 5.1 to 6.0. The data consist of analog and digital records collected at stations ranging in instrumental sophistication from temporary sites with single component smoke drum capability to those of SRO, ASRO and array (ILPA) configurations with digitally recorded down-hole observations. The amplitude and frequency measurements of the analog seismograms for the first arrival and the peak amplitude of P coda as well as for the clear S wave signals recorded for different events at the same station are compared.

  6. Scattering of highly excited atoms

    International Nuclear Information System (INIS)

    Raith, W.

    1980-01-01

    Experimental methods to excite atomic beams into Rydberg states and the first results of collision experiments with such beams are reported. For further information see hints under relevant topics. (orig.) [de

  7. High power laser exciter accelerators

    International Nuclear Information System (INIS)

    Martin, T.H.

    1975-01-01

    Recent developments in untriggered oil and water switching now permit the construction of compact, high energy density pulsed power sources for laser excitation. These accelerators, developed principally for electron beam fusion studies, appear adaptable to laser excitation and will provide electron beams of 10 13 to 10 14 W in the next several years. The accelerators proposed for e-beam fusion essentially concentrate the available power from the outside edge of a disk into the central region where the electron beam is formed. One of the main problem areas, that of power flow at the vacuum diode insulator, is greatly alleviated by the multiplicity of electron beams that are allowable for laser excitation. A proposal is made whereby the disk-shaped pulsed power sections are stacked vertically to form a series of radially flowing electron beams to excite the laser gas volume. (auth)

  8. Institute for Nuclear Theory

    International Nuclear Information System (INIS)

    Haxton, W.; Bertsch, G.; Henley, E.M.

    1993-01-01

    This report briefly discussion the following programs of the Institute for Nuclear Theory: fundamental interactions in nuclei; strangeness in hadrons and nuclei; microscopic nuclear structure theory; nuclear physics in atoms and molecules; phenomenology and lattice QCD; and large amplitude collective motion

  9. CSNI collective statement on support facilities for existing and advanced reactors. The function of OECD/Nea joint projects Nea committee on the safety of nuclear installations (CSNI)

    International Nuclear Information System (INIS)

    2008-01-01

    The NEA Committee on the Safety of Nuclear Installations (CSNI) has recently completed a study on the availability and utilisation of facilities supporting safety studies for current and advanced nuclear power reactors. The study showed that significant steps had been undertaken in the past several years in support of safety test facilities, mainly by conducting multinational joint projects centered on the capability of unique test facilities worldwide. Given the positive experience of the safety research projects, it has been recommended that efforts be made to prioritize technical issues associated with advanced (Generation IV) reactor designs and to develop options on how to efficiently obtain the necessary data through internationally co-ordinated research, preparing a gradual extension of safety research beyond the needs set by currently operating reactors. This statement constitutes a reference for future CSNI activities and for safety authorities, R and D centres and industry for internationally co-ordinated research initiatives in the nuclear safety research area. (author)

  10. Autowaves in moving excitable media

    Directory of Open Access Journals (Sweden)

    V.A.Davydov

    2004-01-01

    Full Text Available Within the framework of kinematic theory of autowaves we suggest a method for analytic description of stationary autowave structures appearing at the boundary between the moving and fixed excitable media. The front breakdown phenomenon is predicted for such structures. Autowave refraction and, particulary, one-side "total reflection" at the boundary is considered. The obtained analytical results are confirmed by computer simulations. Prospects of the proposed method for further studies of autowave dynamics in the moving excitable media are discussed.

  11. Electron-excited molecule interactions

    International Nuclear Information System (INIS)

    Christophorou, L.G.; Tennessee Univ., Knoxville, TN

    1991-01-01

    In this paper the limited but significant knowledge to date on electron scattering from vibrationally/rotationally excited molecules and electron scattering from and electron impact ionization of electronically excited molecules is briefly summarized and discussed. The profound effects of the internal energy content of a molecule on its electron attachment properties are highlighted focusing in particular on electron attachment to vibrationally/rotationally and to electronically excited molecules. The limited knowledge to date on electron-excited molecule interactions clearly shows that the cross sections for certain electron-molecule collision processes can be very different from those involving ground state molecules. For example, optically enhanced electron attachment studies have shown that electron attachment to electronically excited molecules can occur with cross sections 10 6 to 10 7 times larger compared to ground state molecules. The study of electron-excited molecule interactions offers many experimental and theoretical challenges and opportunities and is both of fundamental and technological significance. 54 refs., 15 figs

  12. Formation and de-excitation of hot nuclei in reactions induced by proton beams (475 MeV and 2 GeV) and 3He beam (2 GeV)

    International Nuclear Information System (INIS)

    Ledoux, X.

    1995-04-01

    We are studying the formation and the de-excitation of hot nuclei created in reactions induced by light high energy projectiles. These reactions, described in a two step model: an intranuclear cascade followed by an evaporation phase, produce nuclei in which the collective modes (compression, rotation, deformation) are weakly excited. By measuring the neutron multiplicities, event by event with ORION, and the light charged particle energies and multiplicities one can evaluate the excitation energy distribution of the nuclei. At the same time, theoretical simulations are carried out using the intranuclear cascade code developed by J. Cugnon and the statistical de-excitation code GEMINI. The good agreement with experimental results indicate that 10% of the p-nucleus interactions lead to temperatures greater than 5 MeV. The observation of the fission of a nucleus with a temperature close to 5 MeV shows that the nucleus behaves as a set of bound nucleons and, that the temperature stability limit is not yet reached. The observed decline of fission probability at high excitation energies is most likely to be correlated to the appearance of an other de-excitation process (evaporation residues emission or multifragmentation) which could not be experimentally detected. Finally, in the last chapter, we briefly present the principle of transmutation for long-lived nuclear waste with a proton accelerator and underline the interest of the present work in such studies. (author). 54 refs., 80 figs., 13 tabs

  13. Enhanced nuclear level decay in hot dense plasmas

    International Nuclear Information System (INIS)

    Gosselin, G.; Morel, P.

    2004-01-01

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

  14. Search for excited electrons in ep collisions at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Aaron, F.D. [National Inst. for Physics and Nuclear Engineering (NIPNE), Bucharest (Romania)]|[Bucharest Univ. (Romania). Faculty of Physics; Alexa, C. [National Inst. for Physics and Nuclear Engineering (NIPNE), Bucharest (Romania); Andreev, V. [Lebedev Physical Inst., Moscow (RU)] (and others)

    2008-05-15

    A search for excited electrons is performed using the full e{sup {+-}}p data sample collected by the H1 experiment at HERA, corresponding to a total luminosity of 475 pb{sup -1}. The electroweak decays of excited electrons e{sup *} {yields}e{gamma}, e{sup *} {yields}eZ and e{sup *} {yields}{nu}W with subsequent hadronic or leptonic decays of the W and Z bosons are considered. No evidence for excited electron production is found. Mass dependent exclusion limits on e{sup *} production cross sections and on the ratio f/{lambda} of the coupling to the compositeness scale are derived within gauge mediated models. These limits extend the excluded region compared to previous excited electron searches. The e{sup *} production via contact interactions is also addressed for the first time in ep collisions. (orig.)

  15. Search for excited quarks in ep collisions at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Aaron, F.D. [National Inst. for Physics and Nuclear Engineering (NIPNE), Bucharest (Romania); Bucharest Univ. (Romania). Faculty of Physics; Alexa, C. [National Inst. for Physics and Nuclear Engineering (NIPNE), Bucharest (Romania); Alimujiang, K. [DESY, Hamburg (DE)] (and others)

    2009-03-15

    A search for excited quarks is performed using the full e{sup {+-}}p data sample collected by the H1 experiment at HERA, corresponding to a total integrated luminosity of 475 pb{sup -1}. The electroweak decays of excited quarks q{sup *}{yields}q{gamma}, q{sup *}{yields}qZ and q{sup *}{yields}qW with subsequent hadronic or leptonic decays of the W and Z bosons are considered. No evidence for first generation excited quark production is found. Mass dependent exclusion limits on q{sup *} production cross sections and on the ratio f/{lambda} of the coupling to the compositeness scale are derived within gauge mediated models. These limits extend the excluded region compared to previous excited quark searches. (orig.)

  16. Varieties of Dioptase: Their Magnetic Structure and Collective Excitations

    Science.gov (United States)

    Prisk, T.; Hoffmann, C.; Kolesnikov, A.; Anovitz, L. M.; Matsuda, M.; Podlesnyak, A.; Yan, J.

    2017-12-01

    Diopase [Cu6Si6O18 * 6 H2O] is a copper cyclosilicate mineral that exists within three different polymorphic forms. In the naturally occurring green phase, micropore channels are formed by corrugated rings of Si6O18 connected by Cu2+ ions. These channels contain rings of water molecules H2O which are co-ordinated to the Cu2+ ions, forming Jahn-Teller distorted octahedra. This results in the polymorph's green color. When the mineral is annealed at 400 C, it transforms into a blue polymorph where the positions of the the water molecules H2O become disordered within the channels. If annealed at 600 C, the water molecules are expelled from crystal structure altogether, leaving intact a framework where where the copper atom has quasi-planar co-ordination with neighboring oxygen atoms. The Cu2+ ions are responsible for the appearance of long-range antiferromagnetic order in green dioptase at 14 K. Comparative magnetic susceptibility measurements of these polymorphs demonstrate that altering the hydration state of the mineral leads to profound changes in its magnetic properties. This is presumably due to the fact that the local environment of the Cu2+ ions is modified by changes in the Cu atom's co-ordination with the water oxygen. Green, blue, and black dioptase together provide a case study in the coupling of a mineral's hydration state to its magnetic properties. In this presentation, we report upon a comparative study of dioptase polymorphs. We have applied heat capacity, magnetic susceptibility, single-crystal diffraction, and inelastic neutron scattering techniques. Magnetic diffraction patterns were obtained using the Polarized Triple Axis Spectrometer at the High Flux Isotope Reactor, while measurements of the spin wave dispersion were performed using the Cold Neutron Chopper Spectrometer at the Spallation Neutron Source. We find that, in green dioptase, the Cu2+ ions form spiral antiferromagnetic chains parallel to the micropore channels. However, in blue dioptase, long-range antiferromagnetic order is completely suppressed down to at least 2 K. Black dioptase undergoes a phase transition at 7 K into a low dimensional antiferromagnet, apparently having a different magnetic structure from its green counterpart.

  17. BCS-BEC crossover in dense relativistic matter: Collective excitations

    Czech Academy of Sciences Publication Activity Database

    Brauner, Tomáš

    2008-01-01

    Roč. 77, č. 9 (2008), 096006/1-096006/11 ISSN 1550-7998 R&D Projects: GA ČR GA202/06/0734 Institutional research plan: CEZ:AV0Z10480505 Keywords : quark matter * dynamical model * gross-neveu Subject RIV: BE - Theoretical Physics Impact factor: 5.050, year: 2008

  18. The 2+ excitation of the Hoyle state

    Directory of Open Access Journals (Sweden)

    Khoa Dao T.

    2016-01-01

    Full Text Available To understand why the 2+ excitation of the Hoyle state was so difficult to observe in the direct reaction experiments with the 12C target, a detailed folding model + coupled-channel analysis of the inelastic α+12C scattering at Elab = 240 and 386 MeV has been done using the complex optical potential and inelastic scattering form factor obtained from the double-folding model using the nuclear transition densities predicted by the antisymmetrized molecular dynamics. With the complex strength of the density dependent nucleon-nucleon interaction fixed by the optical model description of the elastic α+12C scattering, the inelastic scattering form factor was fine tuned to the best coupled-channel description of the (α, α′ cross section measured for each excited state of 12C, and the corresponding isoscalar Eλ transition strength has been accurately determined. The present analysis of the (α, α′ data measured in the energy bins around Ex ≈ 10 MeV has unambiguously revealed the E2 transition strength that should be assigned to the 22+ state of 12C. A very weak transition strength B(E2; 01+ → 22+ ≈ 3 e2fm4 has been established, which is smaller than the E2 strength predicted for the transition from the Hoyle state to the 22+ state by at least two orders of magnitude. This is one of the main reasons why the direct excitation of the 22+ state of 12C has been difficult to observe in the experiments.

  19. Iodine (p,n) and (d,2n) excitation function measurements

    International Nuclear Information System (INIS)

    West, H.I. Jr.; Nuckolls, R.M.; Mustafa, M.G.; Lanier, R.G.

    1991-01-01

    We have measured the nuclear excitation functions for the reactions 127 I (p,n) 127 Xe and 127 I(d,2n) 127 Xe. These results are being used in the interpretation of data obtained from nuclear test diagnostics. 15 refs., 3 figs., 3 tabs

  20. Measurement of excited state static moments

    International Nuclear Information System (INIS)

    Sergolle, Henri

    Electric quadrupole and magnetic dipole moments are defined from a classical description of the nucleus and a quantum expression is given for the operators. The principal characteristics of the moment interaction with an outer electric or magnetic field are recalled. The study of the perturbed angular distributions of nuclear reaction products allows half-lives of high spin isomer states to be measured (from a few ps to several hours). The decay gamma rays present, under certain conditions, a strong anisotropy; in principle only one detector is sufficient to observe the angular distribution; coincidences are unnecessary and a high counting rate becomes possible. The measurement of the Coulomb excitation probabilities give the electric (dynamic and static) moments and indirectly quadrupolar moments; two techniques are used: the analysis of elastically and inelastically scattered particles and measurement of the deexcitation γ rays in coincidence with the scattered ions. Quadrupole moments can be measured from the precession of the angular distribution [fr