WorldWideScience

Sample records for giant dipole modes

  1. Giant dipole modes in heavy-ion reactions

    International Nuclear Information System (INIS)

    Suraud, E.; Schuck, P.

    1988-07-01

    A detailed study of the excitation of giant dipole modes (GDR) in intermediate energy heavy-ion collisions is presented in the framework of a full (non linearized) Landau-Vlasov equation. After having recalled the basic inputs of this dynamical formalism, within insisting upon the limitations of the Uehling-Uhlenbeck collision integral and upon the introduction of a realistic (isospin dependant) effective interaction, we present our tools for analysing the GDR in the simple case of isolated nuclei. We then pass on to simulations of collisions and discuss in some detail isospin modes in the model 12 Be + 12 C reaction. Results obtained for the energy of the excited dipole mode are in agreement with what is expected for excited, rotating, giant dipole oscillations in deformed nuclei

  2. Description of the giant dipole mode in states of high angular momentum

    International Nuclear Information System (INIS)

    Hilton, R.R.

    1982-01-01

    The effects of the Coriolis interaction on the giant dipole mode is discussed within the framework of a cranked deformed oscillator in which dipole-dipole two body forces are taken into account. Energy splittings of the dipole mode in addition to those attributable to the shape are found. (orig.)

  3. Giant Primeval Magnetic Dipoles

    Science.gov (United States)

    Thompson, Christopher

    2017-07-01

    Macroscopic magnetic dipoles are considered cosmic dark matter. Permanent magnetism in relativistic field structures can involve some form of superconductivity, one example being current-carrying string loops (“springs”) with vanishing net tension. We derive the cross-section for free classical dipoles to collide, finding it depends weakly on orientation when mutual precession is rapid. The collision rate of “spring” loops with tension { T }˜ {10}-8{c}4/G in galactic halos approaches the measured rate of fast radio bursts (FRBs) if the loops compose most of the dark matter. A large superconducting dipole (LSD) with mass ˜1020 g and size ˜1 mm will form a ˜100 km magnetosphere moving through interstellar plasma. Although hydromagnetic drag is generally weak, it is strong enough to capture some LSDs into long-lived rings orbiting supermassive black holes (SMBHs) that form by the direct collapse of massive gas clouds. Repeated collisions near young SMBHs could dominate the global collision rate, thereby broadening the dipole mass spectrum. Colliding LSDs produce tiny, hot electromagnetic explosions. The accompanying paper shows that these explosions couple effectively to propagating low-frequency electromagnetic modes, with output peaking at 0.01-1 THz. We describe several constraints on, and predictions of, LSDs as cosmic dark matter. The shock formed by an infalling LSD triggers self-sustained thermonuclear burning in a C/O (ONeMg) white dwarf (WD) of mass ≳1 M ⊙ (1.3 M ⊙). The spark is generally located off the center of the WD. The rate of LSD-induced explosions matches the observed rate of Type Ia supernovae.

  4. TESTING CONVECTIVE-CORE OVERSHOOTING USING PERIOD SPACINGS OF DIPOLE MODES IN RED GIANTS

    Energy Technology Data Exchange (ETDEWEB)

    Montalban, J.; Noels, A.; Dupret, M.-A.; Scuflaire, R. [Institut d' Astrophysique et Geophysique de l' Universite de Liege, Allee du six Aout, 17 B-4000 Liege (Belgium); Miglio, A. [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Ventura, P. [Osservatorio Astronomico di Roma-INAF, via Frascati 33, I-00040 Monteporzio Catone, Rome (Italy)

    2013-04-01

    Uncertainties on central mixing in main-sequence (MS) and core He-burning (He-B) phases affect key predictions of stellar evolution such as late evolutionary phases, chemical enrichment, ages, etc. We propose a test of the extension of extra-mixing in two relevant evolutionary phases based on period spacing ({Delta}P) of solar-like oscillating giants. From stellar models and their corresponding adiabatic frequencies (respectively, computed with ATON and LOSC codes), we provide the first predictions of the observable {Delta}P for stars in the red giant branch and in the red clump (RC). We find (1) a clear correlation between {Delta}P and the mass of the helium core (M{sub He}); the latter in intermediate-mass stars depends on the MS overshooting, and hence it can be used to set constraints on extra-mixing during MS when coupled with chemical composition; and (2) a linear dependence of the average value of the asymptotic period spacing (({Delta}P){sub a}) on the size of the convective core during the He-B phase. A first comparison with the inferred asymptotic period spacing for Kepler RC stars also suggests the need for extra-mixing during this phase, as evinced from other observational facts.

  5. Giant dipole resonance by many levels theory

    International Nuclear Information System (INIS)

    Mondaini, R.P.

    1977-01-01

    The many levels theory is applied to photonuclear effect, in particular, in giant dipole resonance. A review about photonuclear dipole absorption, comparing with atomic case is done. The derivation of sum rules; their modifications by introduction of the concepts of effective charges and mass and the Siegert theorem. The experimental distributions are compared with results obtained by curve adjustment. (M.C.K.) [pt

  6. Giant dipole resonance in hot nuclei

    International Nuclear Information System (INIS)

    Mau, N.V.

    1993-01-01

    Giant resonances built on an excited state of the nucleus at a finite temperature T are studied. The following questions are investigated: how long such collective effects occur in a nucleus when T increases. How the properties of the giant resonances vary when the temperature increases. How the study of giant resonances in hot nuclei can give information on the structure of the nucleus in a highly excited state. The special case of the giant dipole resonance is studied. Some of the experimental results are reviewed and in their theoretical interpretation is discussed. (K.A.). 56 refs., 20 figs., 4 tabs

  7. Giant dipole resonances built on excited states

    International Nuclear Information System (INIS)

    Snover, K.A.

    1983-01-01

    The properties of giant dipole resonances built on excited nuclear states are reviewed, with emphasis on recent results. Nonstatistical (p,γ) reactions in light nuclei, and statistical complex-particle reactions in light and heavy nuclei are discussed. 27 references

  8. Stability of the giant dipole resonance

    International Nuclear Information System (INIS)

    Espino, J.M.; Gallardo, M.

    1987-01-01

    The Giant Dipole Resonance (GDR), because of its stability and its typical period of vibration, can be used as a test for compound nucleus reactions at high temperatures. This stability is studied in a simple model up to 6 MeV of temperature. The experimental methods for getting the properties of the GDR at T ≠ 0 are also commented. (author)

  9. Photon scattering by the giant dipole resonance

    International Nuclear Information System (INIS)

    Bowles, T.J.; Holt, R.J.; Jackson, H.E.; McKeown, R.D.; Specht, J.R.

    1979-01-01

    Although many features of the giant dipole resonance are well known, the coupling between the basic dipole oscillation and other nuclear collective degrees of freedom such as surface vibrations and rotations is poorly understood. This aspect was investigated by elastic and inelastic bremsstrahlung scattering of tagged photons over the energy range 15 to 22 MeV. Target nuclei were 60 Ni, 52 Cr, 56 Fe, 92 Mo, and 96 Mo. Scattering and absorption cross sections are tabulated, along with parameters obtained from a two-Lorentzian analysis of the scattering cross sections; measured spectra are shown. It was necessary to remove Thomson scattering from the experimental results. It was found that coupling to surface vibrations in the giant dipole resonance is much weaker than the dynamic collective model suggests. The elastic scattering cross section for all targets but 60 Ni showed structure that is not evident in the absorption cross section measurement. 12 figures, 2 tables

  10. Effects of thermal and particle-number fluctuations on the giant isovector dipole modes for the 58Ni nucleus in the finite-temperature random-phase approximation

    International Nuclear Information System (INIS)

    Nguyen Dinhdang; Nguyen Zuythang

    1988-01-01

    Using the realistic single-particle energy spectrum obtained in the Woods-Saxon nucleon mean-field potential, we calculate the BCS pairing gap for 58 Ni as a function of temperature taking into account the thermal and particle-number fluctuations. The strength distributions of the electric dipole transitions and the centroids of the isovector giant dipole resonance (IV-GDR) are computed in the framework of the finite-temperature random-phase approximation (RPA) based on the Hamiltonian of the quasiparticle-phonon nuclear model with separate dipole forces. It is shown that the change of the pairing gap at finite temperature can noticeably influence the IV-GDR localisation in realistic nuclei. By taking both thermal and quasiparticle fluctuations in the pairing gap into account the effect of the phase transition from superfluid to normal in the temperature dependence of the IV-GDR centroid is completely smeared out. (author)

  11. Temperature dependence of giant dipole resonance width

    International Nuclear Information System (INIS)

    Vdovin, A.I.; Storozhenko, A.N.

    2005-01-01

    The quasiparticle-phonon nuclear model extended to finite temperature within the framework of the thermo field dynamics is applied to calculate a temperature dependence of the spreading width Γ d own of a giant dipole resonance. Numerical calculations are made for 12S n and 208 Pb nuclei. It is found that the width Γ d own increases with T. The reason of this effect is discussed as well as a relation of the present approach to other ones existing in the literature

  12. Collective Hamiltonians for dipole giant resonances

    International Nuclear Information System (INIS)

    Weiss, L.I.

    1991-07-01

    The collective hamiltonian for the Giant Dipole resonance (GDR), in the Goldhaber-Teller-Model, is analytically constructed using the semiclassical and generator coordinates method. Initially a conveniently parametrized set of many body wave functions and a microscopic hamiltonian, the Skyrme hamiltonian - are used. These collective Hamiltonians are applied to the investigation of the GDR, in He 4 , O 16 and Ca 40 nuclei. Also the energies and spectra of the GDR are obtained in these nuclei. The two sets of results are compared, and the zero point energy effects analysed. (author)

  13. High temperature giant dipole and isoscalar resonances

    International Nuclear Information System (INIS)

    Navarro, J.; Barranco, M.; Garcias, F.; Suraud, E.

    1990-01-01

    We present a systematic study of the Giant Dipole Resonance (GDR) at high temperatures (T > ∼ 4 MeV) in the framework of a semi-classical approximation that uses the m 1 and m 3 RPA sum rules to estimate the GDR mean energy. We focus on the evolution with T of the collective nature of the GDR and of the L = 0,2,3 and 4 isoscalar resonances. We find that the GDR remains particularly collective at high T, suggesting that it might be possible to observe it experimentally even at temperatures close to the maximum one a nucleus can sustain

  14. Giant dipole resonance in hot rotating nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Chakrabarty, D.R. [Bhabha Atomic Research Centre, Nuclear Physics Division, Mumbai (India); Dinh Dang, N. [RIKEN, Nishina Centre for Accelerator-based Science, Saitama (Japan); VINATOM, Institute of Nuclear Science and Technique, Hanoi (Viet Nam); Datar, V.M. [Tata Institute of Fundamental Research, INO Cell, Mumbai (India)

    2016-05-15

    Over the last several decades, extensive experimental and theoretical work has been done on the giant dipole resonance (GDR) in excited nuclei covering a wide range of temperature (T), angular momentum (J) and nuclear mass. A reasonable stability of the GDR centroid energy and an increase of the GDR width with T (in the range∝1-3 MeV) and J are the two well-established results. Some experiments have indicated the saturation of the GDR width at high T. The gradual disappearance of the GDR vibration at much higher T has been observed. Experiments on the Jacobi transition and the GDR built on superdeformed shapes at high rotational frequencies have been reported in a few cases. Theoretical calculations on the damping of the collective dipole vibration, characterised by the GDR width, have been carried out within various models such as the thermal shape fluctuation model and the phonon damping model. These models offer different interpretations of the variation of the GDR width with T and J and have met with varying degrees of success in explaining the experimental data. In this review, the present experimental and theoretical status in this field is discussed along with the future outlook. The interesting phenomenon of the pre-equilibrium GDR excitation in nuclear reactions is briefly addressed. (orig.)

  15. The isoscalar giant dipole resonance and nuclear incompressibility

    International Nuclear Information System (INIS)

    Garg, U.

    2000-01-01

    Complete text of publication follows. The current status of the experimental work on the ISOSCALAR giant dipole resonance (ISGDR) will be reviewed. ISGDR is an exotic mode of collective nuclear vibration and can be described as a hydrodynamical density oscillation in which the volume of the nucleus remains constant and the state can be visualized in the form of a compression wave-analogous to a sound wave-oscillating back and forth through the nucleus. [1] Convincing evidence for the ISGDR has now been obtained in inelastic α-scattering measurements at 200 MeV (IUCF) [2], 240 MeV (Texas A and M) [3] and 400 MeV (RCNP, Osaka) [4]. In all nuclei studied so far, the ISGDR strength is observed to be spread over a rather wide excitation-energy range (up to ∼ 15 MeV). The excitation energy of the ISGDR is related to the nuclear incompressibility, K ∞ . The ISGDR results so far point to a value for K ∞ that is ∼ 30-40% lower than the obtained from the energies of the other compressional mode, the giant monopole resonance. Results from recent theoretical attempts to reconcile this difference will be presented. This work has been supported in part by the U.S. National Science Foundation. (author)

  16. Dependence of the giant dipole strength function on excitation energy

    International Nuclear Information System (INIS)

    Draper, J.E.; Newton, J.O.; Sobotka, L.G.; Lindenberger, H.; Wozniak, G.J.; Moretto, L.G.; Stephens, F.S.; Diamond, R.M.; McDonald, R.J.

    1982-01-01

    Spectra of γ rays associated with deep-inelastic products from the 1150-MeV 136 Xe+ 181 Ta reaction have been measured. The yield of 10--20-MeV γ rays initially increases rapidly with the excitation energy of the products and then more slowly for excitation energies in excess of 120 MeV. Statistical-model calculations with ground-state values of the giant dipole strength function fail to reproduce the shape of the measured γ-ray spectra. This suggests a dependence of the giant dipole strength function on excitation energy

  17. Fragmentation of giant dipole resonance at finite temperature

    International Nuclear Information System (INIS)

    Vdovin, A.

    2005-01-01

    It is well known that the main part of a width of a collective giant resonance built on the ground state in heavy nuclei is due to coupling of one-phonon vibrational states with more complex ones like two phonon or two-particle - two-hole. So it seems natural that the same idea was also explored in studying of the formation and dependence on temperature of a width of giant resonances built on a compound nuclear state. The first microscopic calculations of a giant dipole resonance width at finite temperature have demonstrated its weak dependence on T whereas the experimental width Γ exp strongly increases up to T≤3 MeV. The observed thermal behaviour of Γ exp was attributed mainly to thermal fluctuations of a nuclear shape at finite T . However, further theoretical studies of the problem have shown a strengthening of the GDR spreading with T. We calculate a fragmentation of the giant dipole resonance in hot spherical nuclei within the approach based on the quasiparticle-phonon model extended to finite temperature in with the formalism of thermofield dynamics. The fragmentation of collective giant dipole vibrations at finite T is due to the coupling with 'two-thermal phonon' configurations. The energies and structures of thermal phonon states are calculated from the thermal RPA temperature dependence of the variance σ th of a theoretical E1 strength function and the experimental GDR width Γ exp in 120 Sn. The coupling of thermal phonons is determined by their fermionic structure. The variance σ th of the E1 strength function is found continuously increasing with temperature. The main reason of this behavior is the coupling of the dipole phonons with very low-lying particle-particle (hole-hole) thermal phonons. These phonons are noncollective ones and they appear only at T≠0. The calculated T dependence of σ th is quite similar to that of the experimental width Γ exp in 120 Sn and 208 Pb

  18. The width of the giant dipole resonance at finite temperature

    International Nuclear Information System (INIS)

    Mau, N.V.

    1992-01-01

    A method is proposed to evaluate the effect of the change of the Fermi sea on the width of the giant dipole resonance at finite temperature. In a schematic model it is found that, indeed, in 208 Pb the width increases very sharply up to about T=4 MeV but shows a much weaker variation for higher temperature. (author) 26 refs., 7 figs., 2 tabs

  19. Temperature dependence of spreading width of giant dipole resonance

    International Nuclear Information System (INIS)

    Storozhenko, A.N.; Vdovin, A.I.; Ventura, A.; Blokhin, A.I.

    2002-01-01

    The Quasiparticle-Phonon Nuclear Model extended to finite temperature within the framework of Thermo Field Dynamics is applied to calculate a temperature dependence of the spreading width Γ ↓ of a giant dipole resonance. Numerical calculations are made for 120 Sn and 208 Pb nuclei. It is found that Γ ↓ increases with T. The reason of this effect is discussed as well as a relation of the present approach to other ones, existing in the literature

  20. 'Bi-modal' isoscalar giant dipole strength in 58Ni

    International Nuclear Information System (INIS)

    Nayak, B.K.; Garg, U.; Hedden, M.; Koss, M.; Li, T.; Liu, Y.; Madhusudhana Rao, P.V.; Zhu, S.; Itoh, M.; Sakaguchi, H.; Takeda, H.; Uchida, M.; Yasuda, Y.; Yosoi, M.; Fujimura, H.; Fujiwara, M.; Hara, K.; Kawabata, T.; Akimune, H.; Harakeh, M.N.

    2006-01-01

    The strength distribution of the isoscalar giant dipole resonance (ISGDR) in 58 Ni has been obtained over the energy range 10.5-49.5 MeV via extreme forward angle scattering (including 0 deg.) of 386 MeV α particles. We observe a 'bi-modal' E1 strength distribution for the first time in an A<90 nucleus. The observed ISGDR strength distribution is in reasonable agreement with the predictions of a recent RPA calculation

  1. The natural line shape of the giant dipole resonance

    International Nuclear Information System (INIS)

    Gordon, E.F.; Pitthan, R.

    1977-01-01

    Investigation of photoabsorption experiments in the spherical nucleus 141 Pr, the quasispherical dynamically deformed 197 Au, and the statically deformed 165 Ho showed that the function which describes best the energy dependence of the reduced transition probability is given by the Breit-Wigner form rather than the Lorentz form. However, the form of the resulting measured cross section is approximately of the Lorentz type. The dependence of the giant resonance width GAMMA on the excitation energy was also investigated, and found to be less than 1% per MeV if one considered the known isovector E2 resonance above the giant dipole resonance. Best fit values of the reduced transition probabilities for the three nuclei are given and compared to (e,e') results. (Auth.)

  2. Electromagnetic excitation of the two-phonon giant dipole resonance

    International Nuclear Information System (INIS)

    Emling, H.

    1994-03-01

    It is the aim of this article to summarize our present knowledge on the double isovector giant dipole resonance (DGDR) and our understanding of the electromagnetic excitation mechanism in heavy ion collisions in the relativistic energy regime. In the following chapter, a brief resume on the history of giant resonances is given and, based on their understanding, conclusions on the expected properties of multi-phonon resonances are drawn. In chapter 2, the essential features of electromagnetic heavy ion interactions at (near) relativistic velocities will be illuminated and the theoretical framework is presented, which describes such processes. New experimental methods were required for an appropriate study of Coulomb dissociation processes, which are discussed in chapter 3 together with the experimental results. Chapter 4 is dedicated to summarize the results from electromagnetic excitation studies, to compare with those from alternative methods and, in particular, to contrast experimental findings with theoretical predictions and to address open problems. (orig.)

  3. Breaking of axial symmetry in excited heavy nuclei as identified in giant dipole resonance data

    Energy Technology Data Exchange (ETDEWEB)

    Grosse, E.; Massarczyk, R. [Technische Universitaet Dresden, Institute of Nuclear and Particle Physics, Dresden (Germany); Junghans, A.R. [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiation Physics, Dresden (Germany)

    2017-11-15

    A recent theoretical prediction of a breaking of axial symmetry in quasi all heavy nuclei is confronted to a new critical analysis of photon strength functions of nuclei in the valley of stability. For the photon strength in the isovector giant dipole resonance (IVGDR) regime a parameterization of GDR shapes by the sum of three Lorentzians (TLO) is extrapolated to energies below and above the IVGDR. The impact of non-GDR modes adding to the low energy slope of photon strength is discussed including recent data on photon scattering and other radiative processes. These are shown to be concentrated in energy regions where various model calculations predict intermediate collective strength; thus they are obviously separate from the IVGDR tail. The triple Lorentzian (TLO) ansatz for giant dipole resonances is normalized in accordance to the dipole sum rule. The nuclear droplet model with surface dissipation accounts well for positions and widths without local, nuclide specific, parameters. Very few and only global parameters are needed when a breaking of axial symmetry already in the valley of stability is admitted and hence a reliable prediction for electric dipole strength functions also outside of it is expected. (orig.)

  4. Effect of large neutron excess in the region of the Giant Dipole and Quadrupole Resonance

    CERN Document Server

    Lanza, E G

    1999-01-01

    We study the dipole and quadrupole modes of neutron rich nuclei within the selfconsistent HF + RPA. The presence of neutron skin enhances the mixing of isoscalar and isovector modes. Then it is possible to excite modes of isovector character by an isoscalar probe. In particular we analize the excitation of dipole modes by alpha scattering. The excitation of compressional isoscalar mode is also studied.

  5. Influence of complex particle emission on properties of giant dipole resonance of hot nuclei

    International Nuclear Information System (INIS)

    Wen Wanxin; Jin Genming

    2003-01-01

    The possible reasons for the discrepancy between calculation results based on the statistical evaporation model and experimental data of giant dipole resonance of very hot nuclei are discussed. Both of simulations with the standard CASCADE code and the code coupling complex particle emission are carried out. It is shown that the complex particle emission affects the properties of giant dipole resonance of very hot nuclei

  6. A finite different field solver for dipole modes

    International Nuclear Information System (INIS)

    Nelson, E.M.

    1992-08-01

    A finite element field solver for dipole modes in axisymmetric structures has been written. The second-order elements used in this formulation yield accurate mode frequencies with no spurious modes. Quasi-periodic boundaries are included to allow travelling waves in periodic structures. The solver is useful in applications requiring precise frequency calculations such as detuned accelerator structures for linear colliders. Comparisons are made with measurements and with the popular but less accurate field solver URMEL

  7. A finite element field solver for dipole modes

    International Nuclear Information System (INIS)

    Nelson, E.M.

    1992-01-01

    A finite element field solver for dipole modes in axisymmetric structures has been written. The second-order elements used in this formulation yield accurate mode frequencies with no spurious modes. Quasi-periodic boundaries are included to allow travelling waves in periodic structures. The solver is useful in applications requiring precise frequency calculations such as detuned accelerator structures for linear colliders. Comparisons are made with measurements and with the popular but less accurate field solver URMEL. (author). 7 refs., 4 figs

  8. Isovector giant dipole resonance in hot rotating light nuclei in the calcium region

    International Nuclear Information System (INIS)

    Shanmugam, G.; Thiagasundaram, M.

    1989-01-01

    The isovector giant dipole resonances in hot rotating light nuclei in the calcium region are studied using a rotating anisotropic harmonic oscillator potential and a separable dipole-dipole residual interaction. The influence of temperature on the isovector giant dipole resonance is assumed to occur through the change of deformation of the average field only. Calculations are performed for the three nuclei /sup 40,42/Ca and /sup 46/Ti which have spherical, oblate, and prolate ground states, respectively, to see how their shape transitions at higher excited states affect the isovector giant resonance frequencies built on them. It is seen that, while the width fluctuations present at T = 0 vanish at T = 0.5 MeV in /sup 40,42/Ca, they persist up to T = 1.5 MeV in the case of /sup 46/Ti. This behavior brings out the role of temperature on shell effects which in turn affects the isovector giant dipole resonance widths

  9. Giant dipole resonances in hot nuclear matter in the model of self-relaxing mean field

    International Nuclear Information System (INIS)

    Okolowicz, J.; Ploszajczak, M.; Drozdz, S.; Caurier, E.

    1989-01-01

    The extended time-dependent Hartree-Fock approach is applied for the description of the isovector giant dipole resonance in 40 Ca at finite temperatures. The thermalization process is described using the relaxation-time ansatz for the collision integral. Strong inhibition of the giant-dipole-resonance γ-decay is found due to the fast vaporization of the nuclear surface for thermal excitation energies above E * /A ≅ 4.5 MeV. This pre-equilibrium emission of particles in the vapor phase is associated with the radial expansion of nucleus and with the vanishing particle binding energies mainly for protons. (orig.)

  10. Can we learn about the spin-flip giant dipole resonances with pions

    International Nuclear Information System (INIS)

    Baer, H.W.

    1982-01-01

    Data and calculations for the 40 Ca(π+-,π 0 ) reactions at 164 MeV are shown which indicate that pion scattering possesses a unique signature for separately identifying the 1 - and 2 - spin-isospin components of the giant dipole resonance

  11. The temperature dependence of the width of the giant-dipole resonance

    International Nuclear Information System (INIS)

    Ormand, W.E.; Bortignon, P.F.; Broglia, R.A.

    1996-01-01

    The giant-dipole resonance (GDR) in 120 Sn and 208 Pb is studied as a function of excitation energy, angular momentum, and intrinsic width within the context of the adiabatic model. Theoretical evaluations of the full-width-at-half-maximum (FWHM) for the GDR strength function are compared with recent experimental data and are found to be in good agreement. (orig.)

  12. Data systematics and semidirect decay probability of the giant dipole resonance

    International Nuclear Information System (INIS)

    Ishkhanov, B.S.; Kapitonov, I.M.; Tutyn', I.A.

    1998-01-01

    Information on probability of semidirect decay of giant dipole resonance of nuclei of sd- and fp-shells (A = 16-58) is elaborated on the base of the recent (γ, χγ ' ) experimental results. The shell effect in A-dependence of this probability is discovered

  13. Neutron-skin thickness from the study of the anti-analog giant dipole resonance

    NARCIS (Netherlands)

    Krasznahorkay, A.; Stuhl, L.; Csatlós, M.; Algora, A.; Gulyás, J.; Timár, J.; Paar, N.; Vretenar, D.; Boretzky, K.; Heil, M.; Litvinov, Yu A.; Rossi, D.; Scheidenberger, C.; Simon, H.; Weick, H.; Bracco, A.; Brambilla, S.; Blasi, N.; Camera, F.; Giaz, A.; Million, B.; Pellegri, L.; Riboldi, S.; Wieland, O.; Altstadt, S.; Fonseca, M.; Glorius, J.; Göbel, K.; Heftrich, T.; Koloczek, A.; Kräckmann, S.; Langer, C.; Plag, R.; Pohl, M.; Rastrepina, G.; Reifarth, R.; Schmidt, S.; Sonnabend, K.; Weigand, M.; Harakeh, M. N.; Kalantar-Nayestanaki, N.; Rigollet, C.; Bagchi, S.; Najafi, M. A.; Aumann, T.; Atar, L.; Heine, M.; Holl, M.; Movsesyan, A.; Schrock, P.; Volkov, V.; Wamers, F.; Fiori, E.; Löher, B.; Marganiec, J.; Savran, D.; Johansson, H. T.; Fernández, P. Diaz; Garg, U.; Balabanski, D. L.

    2012-01-01

    The gamma-decay of the anti-analog of the giant dipole resonance (AGDR) has been measured to the isobaric analog state excited in the p(124Sn,n) reaction at a beam energy of 600 MeV/nucleon. The energy of the transition was also calculated with state-of-the-art self-consistent random-phase

  14. A collective model description of the low lying and giant dipole resonant properties of 40424446Ca

    International Nuclear Information System (INIS)

    Weise, J.I.

    1982-01-01

    The low-lying and giant dipole resonant properties of the even-even calcium isotopes are calculated within the framework of the Gneuss-Greiner model and compared with the experimental data. In the low energy region, comparison is also made with the predictions of a coexistence model

  15. Is There a Pronounced Giant Dipole Resonance in 4He?

    International Nuclear Information System (INIS)

    Efros, V.D.; Efros, V.D.; Leidemann, W.; Orlandini, G.; Orlandini, G.

    1997-01-01

    A four-nucleon calculation of the total 4 He photodisintegration cross section is performed. The full final-state interaction is taken into account for the first time. This is achieved via the method of the Lorentz integral transform. Semirealistic NN interactions are employed. Different from the known partial two-body 4 He( γ,n) 3 He and 4 He( γ,p) 3 H cross sections our total cross section exhibits a pronounced giant resonance. Thus, in contrast to older (γ,np) data, we predict quite a strong contribution of the (γ,np) channel at the giant resonance peak energy. copyright 1997 The American Physical Society

  16. Structure of the giant dipole resonance in 208Pb

    International Nuclear Information System (INIS)

    El Naggar, N.M.

    1977-01-01

    A new scheme is devised to study the giant resonance in the heavy magic nucleus 208 Pb. The effect of the 4 + and 5 - collective excitations of the nucleus core is demonstrated. The calculated cross section is compared with the experimental data. (author)

  17. The giant-dipole-resonance effect in coulomb excitation of 10B

    International Nuclear Information System (INIS)

    Vermeer, W.J.; Zabel, T.H.; Esat, M.T.; Kuehner, J.A.; Spear, R.H.; Baxter, A.M.

    1982-04-01

    Coulomb excitation of the 0.718-MeV, Jsup(π) = 1 + , first excited state of 10 B has been studied using projectile excitation by 208 Pb and observing the backward scattered particles. The results give a clear indication of the virtual excitation of the giant dipole resonance as a second-order effect. The observed magnitude is consistent with the usual hydrodynamic model estimate and with a recent shell-model calculation

  18. Thermal and rotational effect on giant dipole resonances in rotating nuclei at high temperature

    International Nuclear Information System (INIS)

    Sugawara-Tanabe, Kazuko; Tanabe, Kosai.

    1986-01-01

    Microscopic calculations are carried out for the giant dipole resonances excited on the thermal high spin states in 162 Er and 166 Er based on the thermal linear response theory with realistic forces and large single-particle space. The dynamical strength function is compared with the experimental γ-ray absorption cross section. The general trend that the resonance energy decreases and the resonance width increases with increasing angular momentum and temperature is well reproduced by the calculations. (author)

  19. OPERATION MODES AND CHARACTERISTICS OF PLASMA DIPOLE ANTENNA

    Directory of Open Access Journals (Sweden)

    Nikolay Nikolaevich Bogachev

    2014-02-01

    Full Text Available Existence modes of  surface electromagnetic wave on a plasma cylinder, operating modes and characteristics of the plasma antenna were studied in this paper. Solutions of the dispersion equation of surface wave were obtained for a plasma cylinder with finite radius for different plasma density values. Operation modes of the plasma asymmetric dipole antenna with finite length and radius were researched by numerical simulation. The electric field distributions of  the plasma antenna in near antenna field and the radiation pattern were obtained. These characteristics were compared to characteristics of the similar metal antenna. Numerical models verification was carried out by comparing of the counted and measured metal antenna radiation patterns.

  20. Controlling magnetic and electric dipole modes in hollow silicon nanocylinders.

    Science.gov (United States)

    van de Haar, Marie Anne; van de Groep, Jorik; Brenny, Benjamin J M; Polman, Albert

    2016-02-08

    We propose a dielectric nanoresonator geometry consisting of hollow dielectric nanocylinders which support geometrical resonances. We fabricate such hollow Si particles with an outer diameter of 108-251 nm on a Si substrate, and determine their resonant modes with cathodo-luminescence (CL) spectroscopy and optical dark-field (DF) scattering measurements. The scattering behavior is numerically investigated in a systematic fashion as a function of wavelength and particle geometry. We find that the additional design parameter as a result of the introduction of a center gap can be used to control the relative spectral spacing of the resonant modes, which will enable additional control over the angular radiation pattern of the scatterers. Furthermore, the gap offers direct access to the enhanced magnetic dipole modal field in the center of the particle.

  1. Excitation of giant modes and decay of hot nuclei

    International Nuclear Information System (INIS)

    Chomaz, Ph.

    1992-01-01

    Several phenomena are discussed which can affect the properties of the Giant Dipole Resonance (GDR) built on excited states. The effect of the N over Z ratio is proposed in the entrance channel to test the hypothesis that the saturation of the GDR strength is due to preequilibrium effects. The important role of the compression is discussed both for the calculation of the temperature and for the other parameters of the Hot GDR. (K.A.) 15 refs.; 9 figs

  2. On Landau Vlasov simulations of giant resonances

    International Nuclear Information System (INIS)

    Pi, M.; Schuck, P.; Suraud, E.; Gregoire, C.; Remaud, B.; Sebille, F.

    1987-05-01

    We present VUU calculations of giant resonances obtained in energetic heavy ion collisions. Also is considered the case of the giant dipole in 40 Ca and the possibility of studying the effects of rotation on such collective modes

  3. Time-dependent shape fluctuations and the giant dipole resonance in hot nuclei: Realistic calculations

    International Nuclear Information System (INIS)

    Alhassid, Y.; Bush, B.; Yale Univ., New Haven, CT

    1990-01-01

    The effects of time-dependent shape fluctuations on the giant dipole resonance (GDR) in hot rotating nuclei are investigated. Using the framework of the Landau theory of shape transitions we develop a realistic macroscopic stochastic model to describe the quadrupole time-dependent shape fluctuations and their coupling to the dipole degrees of freedom. In the adiabatic limit the theory reduces to a previous adiabatic theory of static fluctuations in which the GDR cross section is calculated by averaging over the equilibrium distribution with the unitary invariant metric. Nonadiabatic effects are investigated in this model and found to cause structural changes in the resonance cross section and motional narrowing. Comparisons with experimental data are made and deviations from the adiabatic calculations can be explained. In these cases it is possible to determine from the data the damping of the quadrupole motion at finite temperature. (orig.)

  4. Damping of isovector giant dipole resonances in hot even-even spherical nuclei

    International Nuclear Information System (INIS)

    Dang, N.D.

    1989-01-01

    An approach based on the finite temperature quasiparticle phonon nuclear model (FT-QPNM) with the couplings to (2p2h) states at finite temperature taken into account is suggested for calculations of the damping of giant multipole resonances in hot even-even spherical nuclei. The strength functions for the isovector giant dipole resonance (IV-GDR) are calculated in 58 Ni and 90 Zr for a range of temperatures up to 3 MeV. The results show that the contribution of the interactions with (2p2h) configurations to the IV-GDR spreading width changes weakly with varying temperature. The IV-GDR centroid energy decreases slightly with increasing temperature. The nonvanishing superfluid pairing gap due to thermal fluctuations is included. (orig.)

  5. Search for magnetic dipole strength and giant spin-flip resonances in heavy nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Horen, D. J. [Oak Ridge National Lab., TN (USA); Ikegami, H.; Muraoka, M. [eds.; Osaka Univ., Suita (Japan). Research Center for Nuclear Physics

    1980-01-01

    A description is given of the use of high resolution (n, n) scattering and the (p, n) reaction as tools to investigate highly excited states with emphasis on information pertaining to magnetic dipole strength and giant spin-flip resonances in heavy nuclei. It is shown how the ability to uniquely determine the spins and parities of resonances observed in neutron scattering has been instrumental to an understanding of the distribution of M1 strength in sup(207,208)Pb. Some recent results of (p, n) studies with intermediate energy protons are discussed. Energy systematics of the giant Gamow-Teller (GT) resonance as well as a new ..delta..l = 1, ..delta..S = 1 resonance with J sup(..pi..) = (1,2)/sup -/ are presented. It is shown how the (p, n) reaction might be useful to locate M1 strength in heavy nuclei.

  6. Atlas of giant dipole resonances. Parameters and graphs of photonuclear reaction cross sections

    International Nuclear Information System (INIS)

    Varlamov, A.V.; Varlamov, V.V.; Rudenko, D.S.; Stepanov, M.E.

    1999-01-01

    Parameters of giant dipole resonances (GDR) observed in photonuclear reaction cross sections using various beams of incident photons are presented. Data, given for 200 stable isotopes from 2 H to 243 Am including their natural compositions, were collected from papers published over the years 1951-1996. GDR parameters, such as energy positions, amplitudes and widths, are included into the table and organized by element, isotope and reaction. Graphs of the majority of the photonuclear reaction cross sections, included in the international nuclear data library EXFOR by the end of 1998, are presented. The graphs are provided for 182 stable isotopes and natural compositions. (author)

  7. A study of the giant dipole resonance in doubly even tellurium and cerium isotopes

    International Nuclear Information System (INIS)

    Lepretre, A.; Beil, H.; Bergere, R.; Carlos, P.; Fagot, J.; Miniac, A. de; Veyssiere, A.

    1976-01-01

    The partial photoneutron cross sections [sigma(γ,n)+sigma(γ,pn)] and sigma(γ,2n) of 124 Te, 126 Te, 128 Te, 130 Te and 140 Ce, 142 Ce were measured in the giant dipole resonance region by means of the monochromatic photon beam installation at SACLAY. Absolute total photoneutron cross sections, Lorentz line parameters and integrated cross sections are evaluated. The experimental behaviour of the GDR for the above nuclei and in particular its spreading, is then tentatively interpreted in terms of the improved dynamic collective model using the concept of potential energy surfaces. (Auth.)

  8. Photoexcitation by gamma-ray scattering near threshold and giant dipole resonance

    International Nuclear Information System (INIS)

    Lakosi, L.; Safar, J.; Veres, A.; Sekine, T.; Kaji, H.; Yoshihara, K.

    1993-01-01

    Photoexcitation of 4.5 h half-life 115m In and 56 min half-life 103m Rh isomers by inelastic gamma-ray scattering near threshold and in the giant dipole resonance region has been reviewed. In disagreement with earlier experimental results available in the literature, but in good agreement with our experiments published recently, present calculations indicate that above the photoneutron emission threshold the isomer excitation drops abruptly and remains orders of magnitude smaller than at the threshold, even around resonance maximum. (author)

  9. Studies of photonuclear reactions and photon activation analysis in the giant dipole resonance region using microtrons

    International Nuclear Information System (INIS)

    Tran Duc Thiep; Nguyen Van Do; Nguyen Khac Thi; Truong Thi An; Nguyen Ngoc Son

    2004-01-01

    Microtrons are accelerators of electrons and are simultaneous source of Bremsstrahlung photon flux and fission neutrons. In 1982, a microtron of seventeen trajectories Microtron MT - 17 was put into operation at the National Institute of Physics of Vietnam. Though very modest, microtrons are very useful for developing countries such as Vietnam in both fundamental and applied physics research. During the recent years by using the above mentioned MT - 17 and microtrons from other institutes we have carried out different investigation. In this report we present some results obtained in the studies of photonuclear reactions and photon activation analysis in the giant dipole resonance region. (author)

  10. Survey of the (3He,t) reaction: Excitation of the isobaric analog of the giant dipole resonance

    International Nuclear Information System (INIS)

    Tabor, S.L.; Chang, C.C.; Collins, M.T.; Wagner, G.J.; Wu, J.R.; Halderson, D.W.; Petrovich, F.

    1982-01-01

    The ( 3 He,t) reaction at 130 and 170 MeV has been investigated on targets of 12 C, 16 O, 27 Al, 28 Si, 40 Ca, 46 Ti, and 90 Zr. Data for the ( 3 He, 3 He') reaction were measured simultaneously for reference purposes. Structure is observed in the spectra from the ( 3 He, 3 He') and ( 3 He,t) reaction at the expected positions of the giant quadrupole resonance and the isobaric analog of the giant dipole resonance, respectively. An angular distribution was measured for the suspected giant dipole resonance structure in the 40 Ca( 3 He,t) 40 Sc reaction at 130 MeV. The data are reasonably described by a collective model calculation based on the Goldhaber-Teller model for the giant dipole resonance. Several other strong peaks at excitation energies below the giant dipole resonance are observed in the ( 3 He,t) spectra. Most notable of these are the ones at the expected positions for analogs of well known 1 + states and 1hω stretched states in the targets

  11. Quantitatively analyzing the mechanism of giant circular dichroism in extrinsic plasmonic chiral nanostructures by tracking the interplay of electric and magnetic dipoles.

    Science.gov (United States)

    Hu, Li; Tian, Xiaorui; Huang, Yingzhou; Fang, Liang; Fang, Yurui

    2016-02-14

    Plasmonic chirality has drawn much attention because of tunable circular dichroism (CD) and the enhancement for chiral molecule signals. Although various mechanisms have been proposed to explain the plasmonic CD, a quantitative explanation like the ab initio mechanism for chiral molecules, is still unavailable. In this study, a mechanism similar to the mechanisms associated with chiral molecules was analyzed. The giant extrinsic circular dichroism of a plasmonic splitting rectangle ring was quantitatively investigated from a theoretical standpoint. The interplay of the electric and magnetic modes of the meta-structure is proposed to explain the giant CD. We analyzed the interplay using both an analytical coupled electric-magnetic dipole model and a finite element method model. The surface charge distributions showed that the circular current yielded by the splitting rectangle ring causes the ring to behave like a magneton at some resonant modes, which then interact with the electric modes, resulting in a mixing of the two types of modes. The strong interplay of the two mode types is primarily responsible for the giant CD. The analysis of the chiral near-field of the structure shows potential applications for chiral molecule sensing.

  12. Gravity mode offset and properties of the evanescent zone in red-giant stars

    Science.gov (United States)

    Hekker, S.; Elsworth, Y.; Angelou, G. C.

    2018-03-01

    Context. The wealth of asteroseismic data for red-giant stars and the precision with which these data have been observed over the last decade calls for investigations to further understand the internal structures of these stars. Aim. The aim of this work is to validate a method to measure the underlying period spacing, coupling term, and mode offset of pure gravity modes that are present in the deep interiors of red-giant stars. We subsequently investigate the physical conditions of the evanescent zone between the gravity mode cavity and the pressure mode cavity. Methods: We implement an alternative mathematical description compared to what is used in the literature to analyse observational data and to extract the underlying physical parameters that determine the frequencies of mixed modes. This description takes the radial order of the modes explicitly into account, which reduces its sensitivity to aliases. Additionally, and for the first time, this method allows us to constrain the gravity mode offset ɛg for red-giant stars. Results: We find that this alternative mathematical description allows us to determine the period spacing ΔΠ and the coupling term q for the dipole modes within a few percent of values found in the literature. Additionally, we find that ɛg varies on a star-by-star basis and should not be kept fixed in the analysis. Furthermore, we find that the coupling factor is logarithmically related to the physical width of the evanescent region normalised by the radius at which the evanescent zone is located. Finally, the local density contrast at the edge of the core of red-giant branch models shows a tentative correlation with the offset ɛg. Conclusions: We are continuing to exploit the full potential of the mixed modes to investigate the internal structures of red-giant stars; in this case we focus on the evanescent zone. It remains, however, important to perform comparisons between observations and models with great care as the methods employed

  13. Elementary isovector spin and orbital magnetic dipole modes revisited in the shell model

    International Nuclear Information System (INIS)

    Richter, A.

    1988-08-01

    A review is given on the status of mainly spin magnetic dipole modes in some sd- and fp-shell nuclei studied with inelastic electron and proton scattering, and by β + -decay. Particular emphasis is also placed on a fairly new, mainly orbital magnetic dipole mode investigated by high-resolution (e,e') and (p,p') scattering experiments on a series of fp-shell nuclei. Both modes are discussed in terms of the shell model with various effective interactions. (orig.)

  14. Quantal and thermal dampings of the hot giant dipole resonance due to complex configuration mixing

    CERN Document Server

    Dang, N D; Arima, A

    1999-01-01

    An approach is presented to study the width of the giant dipole resonance (GDR) at non-zero temperature T, which includes all forward-going processes up to two-phonon ones. Calculations are performed in sup 1 sup 2 sup 0 Sn and sup 2 sup 0 sup 8 Pb. An overall agreement between theory and experiment is found. The total width of the GDR due to coupling of the GDR phonon to all ph, pp and hh configurations increases sharply as T increases up to T approx 3 MeV and saturates at T approx 4-6 MeV. The quantal width GAMMA sub Q due to coupling to ph configurations decreases with increasing T. It is almost independent of T if the contribution of two-phonon processes at T not =0 is omitted.

  15. Damping width of giant dipole resonances of cold and hot nuclei: A macroscopic model

    International Nuclear Information System (INIS)

    Mughabghab, S.F.; Sonzogni, A.A.

    2002-01-01

    A phenomenological macroscopic model of the giant dipole resonance (GDR) damping width of cold and hot nuclei with ground-state spherical and near-spherical shapes is developed. The model is based on a generalized Fermi liquid model which takes into account the nuclear surface dynamics. The temperature dependence of the GDR damping width is accounted for in terms of surface and volume components. Parameter-free expressions for the damping width and the effective deformation are obtained. The model is validated with GDR measurements of the following nuclides: 39,40 K, 42 Ca, 45 Sc, 59,63 Cu, 109-120 Sn, 147 Eu, 194 Hg, and 208 Pb, and is compared with the predictions of other models

  16. Study of the giant dipole resonance built on highly excited states in Sn and Dy nuclei

    International Nuclear Information System (INIS)

    Stolk, A.

    1988-01-01

    A study is presented of the giant dipole resonance built on highly excited states. The aim is to get more detailed information on the properties of the GDR and to use it as a tool for the investigation of nuclear structure at high excitation energy. The high energy γ-rays seen from the decay of excited state GDRs in heavy ion fusion reactions reflect the average properties of the states populated by the γ-emission. The measurements at different initial excitation energies of 114 Sn provide information on the nuclear level density near the particle separation energy at an average angular momentum of 10ℎ. The study of shape changes at very high spin in 152-156 Dy nuclei is presented. A theoretical model developed to describe fusion-evaporation reactions is presented. 149 refs.; 63 figs.; 13 tabs

  17. Deformation dependence of the isovector giant dipole resonance: The neodymium isotopic chain revisited

    Directory of Open Access Journals (Sweden)

    L.M. Donaldson

    2018-01-01

    Full Text Available Proton inelastic scattering experiments at energy Ep=200 MeV and a spectrometer scattering angle of 0° were performed on 144,146,148,150Nd and 152Sm exciting the IsoVector Giant Dipole Resonance (IVGDR. Comparison with results from photo-absorption experiments reveals a shift of resonance maxima towards higher energies for vibrational and transitional nuclei. The extracted photo-absorption cross sections in the most deformed nuclei, 150Nd and 152Sm, exhibit a pronounced asymmetry rather than a distinct double-hump structure expected as a signature of K-splitting. This behaviour may be related to the proximity of these nuclei to the critical point of the phase shape transition from vibrators to rotors with a soft quadrupole deformation potential. Self-consistent random-phase approximation (RPA calculations using the SLy6 Skyrme force provide a relevant description of the IVGDR shapes deduced from the present data.

  18. Giant magnons and spiky strings in the Schrödinger/dipole-deformed CFT correspondence

    Science.gov (United States)

    Georgiou, George; Zoakos, Dimitrios

    2018-02-01

    We construct semi-classical string solutions of the Schrödinger Sch 5 × S 5 spacetime, which is conjectured to be the gravity dual of a non-local dipole-deformed CFT. They are the counterparts of the giant magnon and spiky string solutions of the undeformed AdS 5 × S 5 to which they flow when the deformation parameter is turned off. They live in an S 3 subspace of the five-sphere along the directions of which the B-field has non-zero components, having also extent in the Sch 5 part of the metric. Finally, we speculate on the form of the dual field theory operators.

  19. Deformation dependence of the isovector giant dipole resonance: The neodymium isotopic chain revisited

    Science.gov (United States)

    Donaldson, L. M.; Bertulani, C. A.; Carter, J.; Nesterenko, V. O.; von Neumann-Cosel, P.; Neveling, R.; Ponomarev, V. Yu.; Reinhard, P.-G.; Usman, I. T.; Adsley, P.; Brummer, J. W.; Buthelezi, E. Z.; Cooper, G. R. J.; Fearick, R. W.; Förtsch, S. V.; Fujita, H.; Fujita, Y.; Jingo, M.; Kleinig, W.; Kureba, C. O.; Kvasil, J.; Latif, M.; Li, K. C. W.; Mira, J. P.; Nemulodi, F.; Papka, P.; Pellegri, L.; Pietralla, N.; Richter, A.; Sideras-Haddad, E.; Smit, F. D.; Steyn, G. F.; Swartz, J. A.; Tamii, A.

    2018-01-01

    Proton inelastic scattering experiments at energy Ep = 200 MeV and a spectrometer scattering angle of 0° were performed on 144,146,148,150Nd and 152Sm exciting the IsoVector Giant Dipole Resonance (IVGDR). Comparison with results from photo-absorption experiments reveals a shift of resonance maxima towards higher energies for vibrational and transitional nuclei. The extracted photo-absorption cross sections in the most deformed nuclei, 150Nd and 152Sm, exhibit a pronounced asymmetry rather than a distinct double-hump structure expected as a signature of K-splitting. This behaviour may be related to the proximity of these nuclei to the critical point of the phase shape transition from vibrators to rotors with a soft quadrupole deformation potential. Self-consistent random-phase approximation (RPA) calculations using the SLy6 Skyrme force provide a relevant description of the IVGDR shapes deduced from the present data.

  20. Origin of fine structure of the giant dipole resonance in s d -shell nuclei

    Science.gov (United States)

    Fearick, R. W.; Erler, B.; Matsubara, H.; von Neumann-Cosel, P.; Richter, A.; Roth, R.; Tamii, A.

    2018-04-01

    A set of high-resolution zero-degree inelastic proton scattering data on 24Mg, 28Si, 32S, and 40Ca provides new insight into the long-standing puzzle of the origin of fragmentation of the giant dipole resonance (GDR) in s d -shell nuclei. Understanding is achieved by comparison with random phase approximation calculations for deformed nuclei using for the first time a realistic nucleon-nucleon interaction derived from the Argonne V18 potential with the unitary correlation operator method and supplemented by a phenomenological three-nucleon contact interaction. A wavelet analysis allows one to extract significant scales both in the data and calculations characterizing the fine structure of the GDR. The fair agreement for scales in the range of a few hundred keV supports the surmise that the fine structure arises from ground-state deformation driven by α clustering.

  1. Presence of mixed modes in red giants in binary systems

    Directory of Open Access Journals (Sweden)

    Themeßl Nathalie

    2017-01-01

    Full Text Available The frequencies of oscillation modes in stars contain valueable information about the stellar properties. In red giants the frequency spectrum also contains mixed modes, with both pressure (p and gravity (g as restoring force, which are key to understanding the physical conditions in the stellar core. We observe a high fraction of red giants in binary systems, for which g-dominated mixed modes are not pronounced. This trend leads us to investigate whether this is specific for binary systems or a more general feature. We do so by comparing the fraction of stars with only p-dominated mixed modes in binaries and in a larger set of stars from the APOKASC sample. We find only p-dominated mixed modes in about 50% of red giants in detached eclipsing binaries compared to about 4% in the large sample. This could indicate that this phenomenon is tightly related to binarity and that the binary fraction in the APOKASC sample is about 8%.

  2. The 132Sn giant dipole resonance as a constraint on nuclear matter properties

    Science.gov (United States)

    Roach, Brandon; Bonasera, Giacomo; Shlomo, Shalom

    2015-10-01

    Nuclear giant resonances provide a sensitive method for constraining the properties of nuclear matter (NM) - many of which have large uncertainties - and thereby improve the nuclear energy-density functional. In this work, self-consistent Hartree-Fock random-phase approximation (HF-RPA) theory was employed to calculate the strength function and energy of the isovector giant dipole resonance (IVGDR) in the doubly-magic 132Sn nucleus. Several (17) commonly-used Skyrme-type interactions were employed. The correlations between the IVGDR centroid energy and each nuclear matter property were explored, as were correlations between the nuclear matter properties and the 132Sn neutron skin thickness rn -rp . Experimental data for the IVGDR centroid energy was used to constrain the symmetry energy density, the symmetry energy, and its first and second derivatives, respectively, of NM. Further investigation, particularly of nuclides far from stability, will be needed to extend the nuclear energy-density functional to the extremes of density and neutron abundance found in neutron stars and astrophysical nucleosynthesis environments.

  3. Main channels of the decay of the giant dipole resonance in the 20,22Ne nuclei and isospin splitting of the giant dipole resonance in the 22Ne nucleus

    International Nuclear Information System (INIS)

    Varlamov, V.V.; Stepanov, M.E.

    2002-01-01

    Data published in the literature on various photonuclear reactions for the 20,22 Ne isotopes and for their natural mixture are analyzed with the aim of exploring special features of the decay of giant-dipole-resonance states in these two isotopes. With the aid of data on the abundances of the isotopes and on the energy reaction thresholds, the cross sections for the reactions 20,22 Ne[(γ, n) + (γ, np)] and 20,22 Ne[(γ, p) + (γ, np)] are broken down into the contributions from the one-nucleon reactions (γ, n) and (γ, p) and the contributions from the reactions (γ, np). The cross sections evaporation model used here to treat the deexcitation of residual nucle(γ, p) 19,21 F in the energy range E γ = 16.0-28.0 MeV and the cross sections for the reactions 20,22 Ne(γ, np) 18,20 F in the energy range E γ = 23.3-28.0 MeV are estimated. The behavior of the cross-section ratio r = σ(γ, p)/σ(γ, n) for the 22 Ne nucleus as a function of energy is analyzed, and the isospin components of the giant dipole resonance in the 22 Ne nucleus are identified. The contributions of the isospin components of the giant dipole resonance in the 22 Ne nucleus to the cross sections for various photonuclear reactions are determined on the basis of an analysis of the diagram of the excitation and decay of pure isospin states in the 22 Ne nucleus and in nuclei neighboring it, which are members of the corresponding isospin multiplets. The isospin splitting of the giant dipole resonance and the ratio of the intensities of the isospin components are determined to be ΔE = 4.57 ± 0.69 MeV and R = 0.24 ± 0.04, respectively

  4. Elastic and Raman scattering of photons from the giant dipole resonance

    International Nuclear Information System (INIS)

    Bar-Noy, T.

    1978-12-01

    In the present work we investigated nuclear Raman and elastic scattering of photons from the Giant Dipole Resonance (GDR) of medium and heavy nuclei. The photons beams were obtained from thermal neutron capture on V, Fe, Ni, Cu and Cr discs, utilizing the IRR-2 reactor. Nine targets, 159 Tb, 165 Ho, 175 Lu, 181 Ta, 197 Au, 209 Bi, 232 Th, 237 Np, and 238 U, representing all spherical and deformed nuclei in the region of medium and heavy nuclei, were used. As preliminary works, we discovered and investigated the 11.4 MeV γ-line, measured the attenuation coefficients at 9 and 11.4 MeV, performed a numerical calculation of Delbrueck amplitudes and modified the Simple Rotator Model (SRM). The absolute scattering cross-sections were measured for each scatterer at 4-8 different energies, and angular distributions in the range 90 deg to 140 deg were carried out at 9 MeV and 11.4 MeV. The experimental results were compared with theoretical predictions of the modified SRM and the Dynamic Collective Model (DCM). The results proved that the modified SRM describes appropriately the scattering from the GDR, including elastic and Raman absolute cross-sections and their angular distributions. (author)

  5. Comparison of electric dipole and magnetic loop antennas for exciting whistler modes

    International Nuclear Information System (INIS)

    Stenzel, R. L.; Urrutia, J. M.

    2016-01-01

    The excitation of low frequency whistler modes from different antennas has been investigated experimentally in a large laboratory plasma. One antenna consists of a linear electric dipole oriented across the uniform ambient magnetic field B_0. The other antenna is an elongated loop with dipole moment parallel to B_0. Both antennas are driven by the same rf generator which produces a rf burst well below the electron cyclotron frequency. The antenna currents as well as the wave magnetic fields from each antenna are measured. Both the antenna currents and the wave fields of the loop antenna exceed that of the electric dipole by two orders of magnitude. The conclusion is that loop antennas are far superior to dipole antennas for exciting large amplitude whistler modes, a result important for active wave experiments in space plasmas.

  6. Comparison of electric dipole and magnetic loop antennas for exciting whistler modes

    Energy Technology Data Exchange (ETDEWEB)

    Stenzel, R. L.; Urrutia, J. M. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States)

    2016-08-15

    The excitation of low frequency whistler modes from different antennas has been investigated experimentally in a large laboratory plasma. One antenna consists of a linear electric dipole oriented across the uniform ambient magnetic field B{sub 0}. The other antenna is an elongated loop with dipole moment parallel to B{sub 0}. Both antennas are driven by the same rf generator which produces a rf burst well below the electron cyclotron frequency. The antenna currents as well as the wave magnetic fields from each antenna are measured. Both the antenna currents and the wave fields of the loop antenna exceed that of the electric dipole by two orders of magnitude. The conclusion is that loop antennas are far superior to dipole antennas for exciting large amplitude whistler modes, a result important for active wave experiments in space plasmas.

  7. Properties of Hot and Fast Rotating Atomic Nuclei Studied by Means of Giant Dipole Resonance in Exclusive Experiments

    International Nuclear Information System (INIS)

    Maj, A.

    2000-01-01

    This work entitled ''Properties of hot and fast rotating atomic nuclei studied by means of Giant Dipole Resonance in exclusive experiments'', is the habilitation thesis of dr. Adam Maj. It consists of the review (in Polish) of performed research and of attached reprints from 16 original publications (in English) which A. Maj is the main or one of the main authors. All the studies were performed in collaboration with the groups from Milano and Copenhagen, using the HECTOR array equipment (described in chapter V). The Giant Dipole Resonance couples to the quadrupole degrees of freedom of the nucleus, and therefore constitutes a unique probe to test the shapes of atomic nuclei. In addition, the γ decay of the GDR from highly excited nuclei is a very fast process, it can compete with other modes of nuclear decay, and therefore can provide the information on the initial stages of excited nuclei. The presented investigations were concentrated on the following aspects: the shapes and thermal shape fluctuations, the origin of the behaviour of the GDR width, the properties of some exotic nuclei (Jacobi shapes, superdeformation, superheavy nuclei) and on ''entrance channel'' effects. The GDR γ decay was measured for nuclei with very different masses: from light nuclei with A≅45, through A≅110, 145,170,190, up to superheavy nuclei with A≅270. The shapes of hot nuclei are not fixed but fluctuate. The extent of these fluctuations and their influence on the measured quantities (GDR strength function, angular distribution and effective shape) is discussed in chapter VI.1. The observed width of the GDR is found to arise from the interplay of two effects: the thermal shape fluctuations, which are controlled by the nuclear temperature, and the deformation effects, controlled by the angular momentum. The ''collisional damping'' effect, which should influence the intrinsic GDR width, was found to be negligible (chapter VI.2). The GDR γ decay from hot superheavy nucleus 272 Hs

  8. Giant nuclear resonances

    International Nuclear Information System (INIS)

    Snover, K.A.

    1989-01-01

    Giant nuclear resonances are elementary mods of oscillation of the whole nucleus, closely related to the normal modes of oscillation of coupled mechanical systems. They occur systematically in most if not all nuclei, with oscillation energies typically in the range 10-30 MeV. One of the best - known examples is the giant electric dipole (El) resonance, in which all the protons and all the neutrons oscillate with opposite phase, producing a large time - varying electric dipole moment which acts as an effective antenna for radiating gamma ray. This paper discusses this mode as well as quadrupole and monopole modes

  9. Dipole strength distribution below the giant dipole resonance in {sup 92}Mo, {sup 98}Mo and {sup 100}Mo

    Energy Technology Data Exchange (ETDEWEB)

    Rusev, G.Y.

    2006-07-01

    Investigations of the dipole-strength distributions in {sup 92}Mo, {sup 98}Mo and {sup 100}Mo were carried out by means of the method of nuclear resonance fluorescence. The low-lying excitations in the nuclides {sup 92}Mo, {sup 98}Mo and {sup 100}Mo have been studied in photon-scattering experiments at an electron energy of 6 MeV at the ELBE accelerator and at electron energies from 3.2 to 3.8 MeV at the Dynamitron accelerator. Five levels were observed in {sup 92}Mo. Five levels in {sup 98}Mo and 14 in {sup 100}Mo were identified for the first time in the energy range from 2 to 4 MeV. Dipole-strength distributions up to the neutron-separation energies in the nuclides {sup 92}Mo, {sup 98}Mo and {sup 100}Mo have been investigated at the ELBE accelerator. Because of the possible observation of transitions in the neighboring nuclei produced via ({gamma},n) reaction, additional measurements at electron energies of 8.4 and 7.8 MeV, below the neutron-separation energy, were performed on {sup 98}Mo and {sup 100}Mo, respectively. The number of transitions assigned to {sup 92}Mo, {sup 98}Mo and {sup 100}Mo is 340, 485 and 499, respectively, the main part of them being dipole transitions. Statistical properties of the observed transitions are obtained. The continuum contains the ground-state transitions as well as the branching transitions to the low-lying levels and the subsequent deexcitations of these levels. (orig.)

  10. Role of the low-lying isoscalar dipole modes in the polarization potential

    International Nuclear Information System (INIS)

    Bal'butsev, E.B.; Unzhakova, A.V.; Lanza, E.G.; Catania Univ.

    1994-01-01

    An analysis of the real and imaginary parts of the polarization potential in terms of the relative contributions of the single collective states for the 208 Pb + 208 Pb system has been done. The polarization potential has been calculated within the Feshbach formalism taking into account the collective states calculated with the Wigner function moments method. The contribution of the isoscalar giant dipole resonance states has been estimated being of the order of 10-20% of the total at relatively low incident energy. 14 refs., 4 figs., 1 tab

  11. Dual-mode plasmonic nanorod type antenna based on the concept of a trapped dipole.

    Science.gov (United States)

    Panaretos, Anastasios H; Werner, Douglas H

    2015-04-06

    In this paper we theoretically investigate the feasibility of creating a dual-mode plasmonic nanorod antenna. The proposed design methodology relies on adapting to optical wavelengths the principles of operation of trapped dipole antennas, which have been widely used in the low MHz frequency range. This type of antenna typically employs parallel LC circuits, also referred to as "traps", which are connected along the two arms of the dipole. By judiciously choosing the resonant frequency of these traps, as well as their position along the arms of the dipole, it is feasible to excite the λ/2 resonance of both the original dipole as well as the shorter section defined by the length of wire between the two traps. This effectively enables the dipole antenna to have a dual-mode of operation. Our analysis reveals that the implementation of this concept at the nanoscale requires that two cylindrical pockets (i.e. loading volumes) be introduced along the length of the nanoantenna, inside which plasmonic core-shell particles are embedded. By properly selecting the geometry and constitution of the core-shell particle as well as the constitution of the host material of the two loading volumes and their position along the nanorod, the equivalent effect of a resonant parallel LC circuit can be realized. This effectively enables a dual-mode operation of the nanorod antenna. The proposed methodology introduces a compact approach for the realization of dual-mode optical sensors while at the same time it clearly illustrates the inherent tuning capabilities that core-shell particles can offer in a practical framework.

  12. Beam orbit control in TESLA superconducting cavities from dipole mode measurements

    International Nuclear Information System (INIS)

    Paparella, R.

    2006-09-01

    The knowledge of the electromagnetic interaction between a beam and the surrounding vacuum chamber is necessary in order to optimize the accelerator performance in terms of stored current. Many instability phenomena may occur in the machine because of the fields produced by the beam and acting back on itself. Basically, these fields, wake-fields, produce an extra voltage, affecting the longitudinal dynamics, and a transverse kick which deflects the beam. In this thesis we present the results of theoretical and experimental investigations to demonstrate the possibility of using the dipolar wake fields of the superconducting accelerating to measure the beam transverse position. After an introduction to the ILC project and to the TESLA technology, of superconducting RF cavities, we will approach the problem from an analytical point of view in chapter 2. The expression of the wake fields in a cylindrical cavity will be investigated and the electromagnetic field modes derived from Maxwell equations in an original way. Graphical solutions of a Matlab program simulating the fields due to a particle passing through a pill-box cavity along a generic path will be shown. The interaction of the beam with higher order modes (HOM) in the TESLA cavities has been studied in the past at the TESLA Test Facility (TTF) in order to determine whether the modes with the highest loss factor are sufficiently damped. Starting from the results obtained before 2003, HOM signals has been better observed and examined in order to use dipole modes to find the electric center of each cavity in the first TTF accelerating module. The results presented in chapter 3 will show that by monitoring the HOM signal amplitude for two polarizations of a dipole mode, one can measure electrical center of the modes with a resolution of 50 μm. Moreover, a misalignment of the first TTF module with respect to the gun axis has been predicted using cavity dipole modes. Alternatives to this method are described in

  13. Empty-electronic-state evolution for Sc and electron dynamics at the 3p-3d giant dipole resonance

    International Nuclear Information System (INIS)

    Hu, Y.; Wagener, T.J.; Gao, Y.; Weaver, J.H.

    1989-01-01

    Inverse photoemission has been used to study the developing electronic states of an early transition metal, Sc, during thin-film growth and to investigate the effects of these states on the 3p-3d giant dipole resonance. Energy- and coverage-dependent intensity variations of the empty Sc states show that the 3d maximum moves 1.1 eV toward the Fermi level as the thickness of the Sc film increases from 1 to 300 A as measured with an incident electron energy of 41.25 eV, an effect attributed to metallic band formation via hybridization of atomic 4s and 3d states. Incident-energy-dependent intensity variations for these empty Sc features show resonant photon emission for incident electron energies above the 3p threshold, with maxima at 43 and 44 eV for 300- and 5-A-thick films, respectively. Considerations of hybridization-induced energy shifts of the empty Sc 3d states demonstrate that the radiative energy changes very little with Sc coverages. These studies indicate coupling of decay channels involving the inverse photoemission continuum and the recombination of the atomic 3p-3d giant dipole transition, the energy of the latter being determined by atomic 3p-3d excitation processes

  14. Higher order mode spectra and the dependence of localized dipole modes on the transverse beam position in third harmonic superconducting cavities at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Pei [Manchester Univ. (United Kingdom); Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Baboi, Nicoleta [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Jones, Roger M. [The Cockcroft Institute, Daresbury (United Kingdom)

    2012-06-15

    An electron beam entering an accelerating cavity excites a wakefield. This wakefield can be decomposed into a series of multi-poles or modes. The dominant component of the transverse wakefield is dipole. This report summarizes the higher order mode (HOM) signals of the third harmonic cavities of FLASH measured at various stages: transmission measurements in the single cavity test stand at Fermilab, at CMTB (Cryo- Module Test Bench) and at FLASH, and beam-excited measurements at FLASH. Modes in the first two dipole bands and the fifth dipole band have been identified using a global Lorentzian fit technique. The beam-pipe modes at approximately 4 GHz and some modes in the fifth dipole band have been observed as localized modes, while the first two dipole bands, containing some strong coupling cavity modes, propagate. This report also presents the dependence of the localized dipole modes on the transverse beam position. Linear dependence for various modes has been observed. This makes them suitable for beam position diagnostics. These modes, together with some propagating, strong coupling modes, have been considered in the design of a dedicated electronics for beam diagnostics with HOMs for the third harmonic cavities.

  15. QPM Analysis of 205Tl Nuclear Excitations below the Giant Dipole Resonance

    Science.gov (United States)

    Benouaret, N.; Beller, J.; Isaak, J.; Kelley, J. H.; Pai, H.; Pietralla, N.; Ponomarev, V. Yu.; Raut, R.; Romig, C.; Rusev, G.; Savran, D.; Scheck, M.; Schnorrenberger, L.; Sonnabend, K.; Tonchev, A. P.; Tornow, W.; Weller, H. R.; Zweidinger, M.

    2015-05-01

    We analysed our experimental recent findings of the dipole response of the odd-mass stable nucleus 205Tl within the quasi-particle phonon model. Using the phonon basis constructed for the neighbouring 204Hg and wave function configurations for 205Tl consisting of a mixture of quasiparticle ⊗ N-phonon configurations (N=0,1,2), only one group of fragmented dipole excited states has been reproduced at 5.5 MeV in comparison to the experimental distribution which shows a second group at about 5 MeV. The computed dipole transition strengths are mainly of E1 character which could be associated to the pygmy dipole resonance.

  16. QPM Analysis of 205Tl Nuclear Excitations below the Giant Dipole Resonance

    Directory of Open Access Journals (Sweden)

    Benouaret N.

    2015-01-01

    Full Text Available We analysed our experimental recent findings of the dipole response of the odd-mass stable nucleus 205Tl within the quasi-particle phonon model. Using the phonon basis constructed for the neighbouring 204Hg and wave function configurations for 205Tl consisting of a mixture of quasiparticle ⊗ N-phonon configurations (N=0,1,2, only one group of fragmented dipole excited states has been reproduced at 5.5 MeV in comparison to the experimental distribution which shows a second group at about 5 MeV. The computed dipole transition strengths are mainly of E1 character which could be associated to the pygmy dipole resonance.

  17. Pygmy and core polarization dipole modes in 206Pb: Connecting nuclear structure to stellar nucleosynthesis

    Science.gov (United States)

    Tonchev, A. P.; Tsoneva, N.; Bhatia, C.; Arnold, C. W.; Goriely, S.; Hammond, S. L.; Kelley, J. H.; Kwan, E.; Lenske, H.; Piekarewicz, J.; Raut, R.; Rusev, G.; Shizuma, T.; Tornow, W.

    2017-10-01

    A high-resolution study of the electromagnetic response of 206Pb below the neutron separation energy is performed using a (γ → ,γ‧) experiment at the HI γ → S facility. Nuclear resonance fluorescence with 100% linearly polarized photon beams is used to measure spins, parities, branching ratios, and decay widths of excited states in 206Pb from 4.9 to 8.1 MeV. The extracted ΣB (E 1) ↑ and ΣB (M 1) ↑ values for the total electric and magnetic dipole strength below the neutron separation energy are 0.9 ± 0.2 e2fm2 and 8.3 ± 2.0 μN2, respectively. These measurements are found to be in very good agreement with the predictions from an energy-density functional (EDF) plus quasiparticle phonon model (QPM). Such a detailed theoretical analysis allows to separate the pygmy dipole resonance from both the tail of the giant dipole resonance and multi-phonon excitations. Combined with earlier photonuclear experiments above the neutron separation energy, one extracts a value for the electric dipole polarizability of 206Pb of αD = 122 ± 10 mb /MeV. When compared to predictions from both the EDF+QPM and accurately calibrated relativistic EDFs, one deduces a range for the neutron-skin thickness of Rskin206 = 0.12- 0.19 fm and a corresponding range for the slope of the symmetry energy of L = 48- 60 MeV. This newly obtained information is also used to estimate the Maxwellian-averaged radiative cross section 205Pb (n , γ)206Pb at 30 keV to be σ = 130 ± 25 mb. The astrophysical impact of this measurement-on both the s-process in stellar nucleosynthesis and on the equation of state of neutron-rich matter-is discussed.

  18. Soft dipole mode of 11Li in approximation of asymptotic potential

    International Nuclear Information System (INIS)

    Filippov, G.F.; Lashko, Yu.A.

    2001-01-01

    The soft dipole mode of 11 Li is studied in the frame of microscopic tri-cluster model and in the asymptotic potential approximation. The theory reproduces well the ground state energy, matter radius and the behaviour of the effective photodisintegration cross section in the range of low energies above the decay threshold of 11 Li. Our calculations point two resonant states in this range [ru

  19. Analyzing intrinsic plasmonic chirality by tracking the interplay of electric and magnetic dipole modes.

    Science.gov (United States)

    Hu, Li; Huang, Yingzhou; Pan, Lujun; Fang, Yurui

    2017-09-11

    Plasmonic chirality represents significant potential for novel nanooptical devices due to its association with strong chiroptical responses. Previous reports on plasmonic chirality mechanism mainly focus on phase retardation and coupling. In this paper, we propose a model similar to the chiral molecules for explaining the intrinsic plasmonic chirality mechanism of varies 3D chiral structures quantitatively based on the interplay and mixing of electric and magnetic dipole modes (directly from electromagnetic field numerical simulations), which forms mixed electric and magnetic polarizability.

  20. Dipole modes of a superfluid Bose–Fermi mixture in the BCS-BEC crossover

    International Nuclear Information System (INIS)

    Wen, Wen; Chen, Bingyan; Zhang, Xuewu

    2017-01-01

    Motivated by the first experimental realization by the Ecole Normale Supérieure (ENS) group of a mixture of a Bose–Einstein condensate with a Fermi superfluid continuously changing from a Bardeen–Cooper–Schrieffer (BCS) superfluid to a Bose–Einstein condensate (BEC) (Ferrier-Barbut et al 2014 Science 345 1035), we analytically study the dipole modes of the superfluid Bose–Fermi mixture in the BCS-BEC crossover. The analytical approach can explicitly reveal relationships between the frequencies of the dipole modes and the microscopic properties of the novel system. We start from coupled hydrodynamic equations, where the equation of state for the Fermi superfluid in the crossover is an analytical fitting formula based on experimental data, and by using a scaling approach we analytically study eigenfrequencies of the dipole modes for the coupled system in the ENS experimental parameters. Without the boson–fermion interaction in the equilibrium density profiles, our theoretical results can be reduced to the mean-field model and is consistent with the experimental data. However, by further taking into account the boson–fermion interaction numerically and analytically, we find that the results disagree with the experiment, especially in the parameter regime where the boson interaction is smaller than the boson–fermion interaction. (paper)

  1. Heavy ion coulomb excitation and gamma decay studies of the one and two phonon giant dipole resonances in 208Pb and 209Bi

    International Nuclear Information System (INIS)

    Mueller, P.E.; Beene, J.R.; Bertrand, F.E.; Halbert, M.L.; Olive, D.H.; Varner, R.L.; Sherrill, B.; Thoennessen, M.; Lautridou, P.; Lefevre, F.; Marques, M.; Matulewicz, T.; Mittig, W.; Ostendorf, R.; Roussel-Chomaz, P.; Schutz, Y.; Pol, J. van; Wilschut, H.W.; Diaz, J.; Ferrero, J.L.; Marin, A.

    1994-01-01

    Projectile - phonon coincidences were measured for the scattering of an 80 MeV/nucleon 64 Zn beam from 208 Pb and 209 Bi targets at the GANIL heavy ion accelerator facility. Projectile-like particles between 0.5 and 4.5 relative to the incident beam direction were detected in the SPEG energy loss spectrometer where their momentum, charge, and mass were determined. Photons were detected in the BaF 2 scintillation detector array TAPS. Light charged particles produced in the reaction were detected in the KVI Forward Wall. The analysis of the data acquired in this experiment is focused on three different phenomena: (1) the two phonon giant dipole resonance, (2) time dependence of the decay of the one phonon giant dipole resonance, and (3) giant resonance strength in projectile nuclei. (orig.)

  2. The approximation of asymptotic potential and the soft dipole mode of the 6He

    International Nuclear Information System (INIS)

    Filippov, G.F.; Lashko, Yu.A.; Shvrdov, L.P.; Kato, K.

    1999-01-01

    The soft dipole mode of a three-cluster 6 He nucleus is investigated on the basis of the generalized version of the zero-radius nuclear forces approximation, taking into account a slowly decreasing asymptotic potential and influence of the Paulo exclusion principle on the asymptotic of the wave function, and also the fact of degeneration of 1 - continuous spectrum states. The issue of the behaviour of matrix elements of the two-channel S-matrix and problem of existence of the super-threshold 1 - resonance are discussed [ru

  3. Gravity modes as a way to distinguish between hydrogen- and helium-burning red giant stars

    DEFF Research Database (Denmark)

    Bedding, Timothy R.; Mosser, Benoit; Huber, Daniel

    2011-01-01

    Red giants are evolved stars that have exhausted the supply of hydrogen in their cores and instead burn hydrogen in a surrounding shell. Once a red giant is sufficiently evolved, the helium in the core also undergoes fusion. Outstanding issues in our understanding of red giants include...... uncertainties in the amount of mass lost at the surface before helium ignition and the amount of internal mixing from rotation and other processes. Progress is hampered by our inability to distinguish between red giants burning helium in the core and those still only burning hydrogen in a shell....... Asteroseismology offers a way forward, being a powerful tool for probing the internal structures of stars using their natural oscillation frequencies. Here we report observations of gravity-mode period spacings in red giants that permit a distinction between evolutionary stages to be made. We use high...

  4. Effect of dipole interaction on collective modes in 3He-A

    International Nuclear Information System (INIS)

    Tewordt, L.; Schopohl, N.; Vollhardt, D.

    1977-01-01

    A general theory for the correlation functions of superfluid 3 He which takes into account rigorously the magnetic dipole interaction is developed. The resulting equations are solved for the Anderson--Brinkman--Morel (ABM) state and for wave vectors q oriented parallel to the energy gap axis. Then the dispersion relations of low-frequency modes, including Fermi liquid corrections and damping due to pair breaking, are calculated in the zero-temperature and zero-field limit. There are two real frequency modes arising from each of the longitudinal and transverse spin density correlation functions: a spin wave and an orbit wave, both exhibiting a frequency gap where that of the spin wave is somewhat modified in comparison to the unperturbed longitudinal nuclear magnetic resonance frequency Ω/sup ABM//sub L/. The orbit wave is damped much more strongly than the spin wave. Further, there are two real frequency modes arising from the density correlation function: the sound wave, having a frequency gap of the order Ω/sup ABM//sub L/, and an orbit wave, exhibiting a gap in wave number of order Ω/sup ABM//sub L//v/sub F/.: The NMR frequency undergoes a small splitting, which is the result of the splitting of the energy gap due to the dipole interaction. One of the two gaps still has nodes.: In addition to these low-frequency modes our equations yield resonances at frequencies of the order of the gap frequency Δ 0 /h, i.e., at ω=1.22Δ 0 /h and at ω=1.58 Δ 0 /h. The damping and the oscillator strengths of these resonances are calculated

  5. Effect of dipole-quadrupole Robinson mode coupling upon the beam response to radio-frequency phase noise

    Directory of Open Access Journals (Sweden)

    R. A. Bosch

    2006-09-01

    Full Text Available In an electron storage ring, coupling between dipole and quadrupole Robinson oscillations modifies the spectrum of longitudinal beam oscillations driven by radio-frequency (rf generator phase noise. In addition to the main peak at the resonant frequency of the coupled dipole Robinson mode, another peak occurs at the resonant frequency of the coupled quadrupole mode. To describe these peaks analytically for a quadratic synchrotron potential, we include the dipole and quadrupole modes when calculating the beam response to generator noise. We thereby obtain the transfer function from generator-noise phase modulation to beam phase modulation with and without phase feedback. For Robinson-stable bunches confined in a synchrotron potential with a single minimum, the calculated transfer function agrees with measurements at the Aladdin 800-MeV electron storage ring. The transfer function is useful in evaluating phase feedback that suppresses Robinson oscillations in order to obtain quiet operation of an infrared beam line.

  6. 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

  7. Improvement of photoneutron spectrum measurement produced by bombardment of 2 GeV electrons above giant dipole resonance region

    International Nuclear Information System (INIS)

    Lee, H. S.; Park, J. S.; Choi, H. D.; Sato, Tatsuhiko; Shin, Kasuo; Ban, Syuichi

    2000-01-01

    Above the Giant Dipole Resonance (GDR) region, high energy photoneutron spectra produced by irradiation of 2.04 GeV electrons into Pb target were measured by Time-of-Flight (TOF) technique. The differential photoneutron yields were obtained at a fixed angle of 90 degrees to the electron beam direction. The TOF system consists of Pilot-U plastic scintillation detector, which has fast response time, and the high speed multiscaler or CAMAC TDC. In the improvement of experimental setup to extend the flight distance to 10.4 m lead to make the measurable energy to 500 MeV from 300 MeV. And using the TDC based electronics lead to use a veto counter. The results were compared with the calculated one by using EGS4 and Modified PICA95. The characteristics of this TOF system was introduced in this paper and the results for several measuring conditions, which are flight distance, TOF electronics, and type of neutron detector, were discussed to improve the accuracy of this measurement

  8. Isomeric ratios in photonuclear reactions of molybdenum isotopes induced by bremsstrahlung in the giant dipole resonance region

    International Nuclear Information System (INIS)

    Tran Duc Thiep; Truong Thi An; Phan Viet Cuong; Nguyen The Vinh; Bui Minh Hue; Belov, A.G.; Maslov, O.D.; Mishinsky, G.V.; Zhemenik, V.I.

    2017-01-01

    We have determined the isomeric ratios of isomeric pairs "9"7"m","gNb, "9"5"m","gNb and "9"1"m","gMo produced in "9"8Mo(γ, p)"9"7"m","gNb, "9"6Mo(γ, p)"9"5"m","gNb and "9"2Mo(γ, n)"9"1"m","gMo photonuclear reactions in the giant dipole resonance (GDR) region by the activation method. The results were analyzed, discussed and compared with the similar data from literature to examine the role of excitation energy, neutron configuration, channel effect, and direct and pre-equilibrium processes in (γ, p) photonuclear reactions. In this work the isomeric ratios for "9"7"m","gNb from 14 to 19 MeV, for "1"9"5"m","gNb from 14 to 24 MeV except 20 and 23.5 MeV and for "9"1"m","gMo at 14 and 15 MeV were first measured.

  9. Overtones of isoscalar giant resonances studied in direct particle decay measurements

    NARCIS (Netherlands)

    Hunyadi, M; van den Berg, AM; Csatlos, M; Csige, L; Davids, B; Garg, U; Gulyas, J; Harakeh, MN; de Huu, MA; Krasznahorkay, A; Sohler, D; Wortche, HJ

    The isoscalar giant dipole resonance (ISGDR), which is the lowest-energy overtone mode of the isoscalar giant resonances, has been studied in some medium-heavy and heavy nuclei in coincidence measurements. The observation of the direct nucleon decay channels significantly helped to enhance giant

  10. Calculations of the giant-dipole-resonance photoneutrons using a coupled EGS4-morse code

    International Nuclear Information System (INIS)

    Liu, J.C.; Nelson, W.R.; Kase, K.R.; Mao, X.S.

    1995-10-01

    The production and transport of the photoneutrons from the giant-dipoleresonance reaction have been implemented in a coupled EGS4-MORSE code. The total neutron yield (including both the direct neutron and evaporation neutron components) is calculated by folding the photoneutron yield cross sections with the photon track length distribution in the target. Empirical algorithms based on the measurements have been developed to estimate the fraction and energy of the direct neutron component for each photon. The statistical theory in the EVAP4 code, incorporated as a MORSE subroutine, is used to determine the energies of the evaporation neutrons. These represent major improvements over other calculations that assumed no direct neutrons, a constant fraction of direct neutrons, monoenergetic direct neutron, or a constant nuclear temperature for the evaporation neutrons. It was also assumed that the slow neutrons ( 2 θ, which have a peak emission at 900. Comparisons between the calculated and the measured photoneutron results (spectra of the direct, evaporation and total neutrons; nuclear temperatures; direct neutron fractions) for materials of lead, tungsten, tantalum and copper have been made. The results show that the empirical algorithms, albeit simple, can produce reasonable results over the interested photon energy range

  11. Giant larvaceans: biologically equivalent flapping flexible foils exhibit bending modes that enhance fluid transport

    Science.gov (United States)

    Katija, Kakani; Sherman, Alana; Robison, Bruce

    2016-11-01

    The midwater region of the ocean (below the euphotic zone and above the benthos) is one of the largest ecosystems on our planet, yet remains one of the least explored. Little-known marine organisms that inhabit midwater have developed life strategies that contribute to their evolutionary success, and may inspire engineering solutions for societally relevant challenges. A group of midwater organisms, known as giant larvaceans (genus Bathochordaeus), beat their tails to drive food and particle-laden water through complex, mucus filtering structures to feed. Giant larvaceans, whose motion and kinematics resemble flapping flexible foils, range in size from 1 to 10 cm in length, and can be found between the surface and 400 m. Using remotely-operated vehicles and DeepPIV, an instrument that enables in situ particle image velocimetry (PIV) measurements, the filtration rates and kinematics of giant larvaceans were investigated. These measurements yielded filtration rates for giant larvaceans as high as 80 L/hr, which exceeds expected filtration rates by a factor of 2 when compared with other larvacean groups. Comparing tail kinematics between Bathochordeaus and smaller larvaceans reveals differences in tail bending modes, where a hinge is present throughout the tail beat in giant larvaceans. Using laboratory PIV measurements with swimming animals and soft-bodied mechanical mimics, we reveal how these differences in tail kinematics can lead to enhanced fluid transport. This work has been supported by the Packard Foundation.

  12. Width and strength of the hot giant dipole resonance. The role of the life time of the compound nucleus and the transition from order to chaos

    International Nuclear Information System (INIS)

    Chomaz, P.

    1996-01-01

    A bump in the γ decay spectrum is observed at high energies which is due to the excitation of the Giant Dipole Resonance (GDR) in the compound nucleus. The fact is discussed that the total width of the γ-ray spectrum of the GDR transitions must contain twice the width of the compound nucleus levels. This implies that one must except a rapid increase of the width of the GDR. This increase contributes to the observed saturation of the photon multiplicity. A new suppression factor due to the lost of collectivity induced by the fast particle emission is proposed. (K.A.)

  13. Comment on 'Angular momentum gated giant dipole resonance measurements in the reaction 28Si+58Ni at E(28Si)=100 and 125 MeV'

    International Nuclear Information System (INIS)

    Heckman, P.; Thoennessen, M.

    2003-01-01

    In a recent paper, the giant dipole resonance width was studied as a function of angular momentum in the nucleus 86 Mo. The width of the resonance was found to be constant over a spin range of (0-40)(ℎ/2π). It was concluded that the angular momentum dependence for 86 Mo differs from that of Sn isotopes. We compared both datasets with a phenomenological formula based on the thermal fluctuation theory. The 86 Mo data are inconsistent with the formula in contrast to the previously analyzed Sn data, which seems to indicate that the angular momentum dependence of the phenomenological model is not universally applicable

  14. Electromagnetic and mechanical design of a 56 mm aperture mode dipole for the LHC

    International Nuclear Information System (INIS)

    Ahlbaeck, J.; Ikaeheimo, J.; Jaervi, J.

    1994-01-01

    The Large Hadron Collider (LHC) project is proposed as the future extension of the CERN accelerator complex. The LHC requires twin aperture superconducting dipoles of highest possible field to guide the proton beams in the existing LEP tunnel of 26.7 km circumference. This paper describes the electromagnetic and mechanical design of a 56 mm aperture model dipole for the LHC

  15. 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

  16. Giant Faraday Rotation of High-Order Plasmonic Modes in Graphene-Covered Nanowires.

    Science.gov (United States)

    Kuzmin, Dmitry A; Bychkov, Igor V; Shavrov, Vladimir G; Temnov, Vasily V

    2016-07-13

    Plasmonic Faraday rotation in nanowires manifests itself in the rotation of the spatial intensity distribution of high-order surface plasmon polariton (SPP) modes around the nanowire axis. Here we predict theoretically the giant Faraday rotation for SPPs propagating on graphene-coated magneto-optically active nanowires. Upon the reversal of the external magnetic field pointing along the nanowire axis some high-order plasmonic modes may be rotated by up to ∼100° on the length scale of about 500 nm at mid-infrared frequencies. Tuning the carrier concentration in graphene by chemical doping or gate voltage allows for controlling SPP-properties and notably the rotation angle of high-order azimuthal modes. Our results open the door to novel plasmonic applications ranging from nanowire-based Faraday isolators to the magnetic control in quantum-optical applications.

  17. Two modes of wave propagation manifested in vertical electric dipole radiation over a sphere

    International Nuclear Information System (INIS)

    Houdzoumis, Vassilios A.

    2000-01-01

    The radiation of a vertical electric dipole over an electrically homogeneous sphere is considered anew, starting with a novel mathematical formulation. Both the dipole and the point of observation are assumed to lie on the spherical interface. The analysis is valid for a sphere whose radius is much larger than the wavelength in the outside region. Contributions to the value of the fields come, on the one hand, from the waves that propagate along the interface and, on the other hand, from the waves that propagate through the sphere by successive reflections. (c) 2000 American Geophysical Union

  18. Determination of the electromagnetic character of soft dipole modes solely based on quasicontinuous γ spectroscopy

    International Nuclear Information System (INIS)

    Voinov, A.; Schiller, A.; Guttormsen, M.; Rekstad, J.; Siem, S.

    2003-01-01

    We show that the combined analysis of quasicontinuous γ spectra from the ( 3 He,α) and (n th ,2γ) reactions gives the possibility to measure the electromagnetic character of soft dipole resonances. Two-step γ-cascade spectra have been calculated, using level densities and radiative strength functions from the ( 3 He,αγ) reaction. The calculations show that the intensity of the two-step cascades depends on the electromagnetic character of the soft dipole resonance under study. The difference reaches 40-100% which can be measured experimentally

  19. The isomeric ratios in photonuclear reactions of natural barium induced by bremsstrahlungs with endpoint energies in the giant dipole resonance region

    International Nuclear Information System (INIS)

    Tran Duc Thiep; Truong Thi An; Phan Viet Cuong; Nguyen The Vinh

    2012-01-01

    We have determined the isomeric ratios in 130 Ba(γ, n) 129m,g Ba, 132 Ba(γ, n) 131m,g Ba and 134 Ba(γ, n) 133m,g Ba photonuclear reactions of natural barium induced by bremsstrahlungs with end-point energies in the giant dipole resonance region. The investigated samples were irradiated at electron accelerator Microtron MT-25 of the Flerov Laboratory of Nuclear Reaction, Joint Institute for Nuclear Research, Dubna, Russia. The gamma spectra of the samples irradiated were measured with spectroscopic system consisting of 8192 channel analyzer and high-energy resolution (180 keV at gamma ray 1332 keV of 60 Co) HP(Ge) semiconductor detector Canberra. The GENIE2000 (Canberra) computer program was used for data processing. The results were discussed and compared with those of other authors. (author)

  20. A study of beam position diagnostics using beam-excited dipole modes in third harmonic superconducting accelerating cavities at a free-electron laser

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Pei [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Deutsches Elektronen-Synchrotron (DESY), 22607 Hamburg (Germany); Baboi, Nicoleta [Deutsches Elektronen-Synchrotron (DESY), 22607 Hamburg (Germany); Jones, Roger M.; Shinton, Ian R. R. [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Cockcroft Institute, Cheshire WA4 4AD (United Kingdom); Flisgen, Thomas; Glock, Hans-Walter [Institut fuer Allgemeine Elektrotechnik, Universitaet Rostock, 18051 Rostock (Germany)

    2012-08-15

    We investigate the feasibility of beam position diagnostics using higher order mode (HOM) signals excited by an electron beam in the third harmonic 3.9 GHz superconducting accelerating cavities at FLASH. After careful theoretical and experimental assessment of the HOM spectrum, three modal choices have been narrowed down to fulfill different diagnostics requirements. These are localized dipole beam-pipe modes, trapped cavity modes from the fifth dipole band, and propagating modes from the first two dipole bands. These modes are treated with various data analysis techniques: modal identification, direct linear regression (DLR), and singular value decomposition (SVD). Promising options for beam diagnostics are found from all three modal choices. This constitutes the first prediction, subsequently confirmed by experiments, of trapped HOMs in third harmonic cavities, and also the first direct comparison of DLR and SVD in the analysis of HOM-based beam diagnostics.

  1. A study of beam position diagnostics using beam-excited dipole modes in third harmonic superconducting accelerating cavities at a free-electron laser

    CERN Document Server

    Zhang, P; Jones, R M; Shinton, I R R; Flisgen, T; Glock, H W

    2012-01-01

    We investigate the feasibility of beam position diagnostics using Higher Order Mode (HOM) signals excited by an electron beam in the third harmonic 3.9 GHz superconducting accelerating cavities at FLASH. After careful theoretical and experimental assessment of the HOM spectrum, three modal choices have been narrowed down to fulfill different diagnostics requirements. These are localized dipole beam-pipe modes, trapped cavity modes from the fifth dipole band and propagating modes from the first two dipole bands. These modes are treated with various data analysis techniques: modal identification, direct linear regression (DLR) and singular value decomposition (SVD). Promising options for beam diagnostics are found from all three modal choices. This constitutes the first prediction, subsequently confirmed by experiments, of trapped HOMs in third harmonic cavities, and also the first direct comparison of DLR and SVD in the analysis of HOM-based beam diagnostics.

  2. Relativistic Coulomb excitation of giant resonances in the hydrodynamic model

    International Nuclear Information System (INIS)

    Vasconcellos Gomes, Ana Cristina de.

    1990-05-01

    We investigate the Coulomb excitation of giant dipole resonances in relativistic heavy ion collisions using a macroscopic hydrodynamical model for the harmonic vibrations of the nuclear fluid. The motion is treated as a combination of the Goldhaber-Teller displacement mode and the Steinwedel-Jensen acoustic mode, and the restoring forces are calculated using the droplet model. This model is used as input to study the characteristics of multiple excitation of giant dipole resonances in nuclei. Possible signatures for the existence of such states are also discussed quantitatively. (author). 52 refs., 14 figs., 3 tabs

  3. Multipole giant resonances in highly excited nuclei

    International Nuclear Information System (INIS)

    Xia Keding; Cai Yanhuang

    1989-01-01

    The isoscalar giant surface resonance and giant dipole resonance in highly excited nuclei are discussed. Excitation energies of the giant modes in 208 Pb are calculated in a simplified model, using the concept of energy wieghted sum rule (EWSR), and the extended Thomas-Fermi approximation at the finite temperature is employed to describe the finite temperature is employed to describe the finite temperature equilibrium state. It is shown that EWSR and the energy of the resonance depend only weakly on temperature in the system. This weak dependence is analysed

  4. Probing the core structure and evolution of red giants using gravity-dominated mixed modes observed with Kepler

    NARCIS (Netherlands)

    Mosser, B.; Goupil, M.J.; Belkacem, K.; Michel, E.; Stello, D.; Marques, J.P.; Elsworth, Y.; Barban, C.; Beck, P.G.; Bedding, T.R.; De Ridder, J.; García, R.A.; Hekker, S.; Kallinger, T.; Samadi, R.; Stumpe, M.C.; Barclay, T.; Burke, C.J.

    2012-01-01

    Context. There are now more than 22 months of long-cadence data available for thousands of red giants observed with the Kepler space mission. Consequently, we are able to clearly resolve fine details in their oscillation spectra and see many components of the mixed modes that probe the stellar core.

  5. Gravity modes as a way to distinguish between hydrogen- and helium-burning red giant stars

    NARCIS (Netherlands)

    Bedding, T.R.; Mosser, B.; Huber, D.; Montalbán, J.; Beck, P.; Christensen-Dalsgaard, J.; Elsworth, Y.P.; García, R.A.; Miglio, A.; Stello, D.; White, T.R.; de Ridder, J.; Hekker, S.; Aerts, C.; Barban, C.; Belkacem, K.; Broomhall, A.M.; Brown, T.M.; Buzasi, D.L.; Carrier, F.; Chaplin, W.J.; Di Mauro, M.P.; Dupret, M.-A.; Frandsen, S.; Gilliland, R.L.; Goupil, M.J.; Jenkins, J.M.; Kallinger, T.; Kawaler, S.; Kjeldsen, H.; Mathur, S.; Noels, A.; Silva Aguirre, V.; Ventura, P.

    2011-01-01

    Red giants are evolved stars that have exhausted the supply of hydrogen in their cores and instead burn hydrogen in a surrounding shell. Once a red giant is sufficiently evolved, the helium in the core also undergoes fusion. Outstanding issues in our understanding of red giants include uncertainties

  6. Properties of a new magnetic dipole mode discovered in low energy electron scattering

    International Nuclear Information System (INIS)

    Bohle, D.; Guhr, T.; Hartmann, U.; Hummel, K.D.; Kilgus, G.; Milkau, U.; Richter, A.

    1986-01-01

    In a large range of nuclei low lying J π =1 + states have been found that are excited predominantly by a new M1 mode. Four properties of the new mode will be discussed in detail. Firstly, from the excitation energy systematics observed the strength of the Majorana force of the interacting boson model (IBA) is deduced. Secondly, through the comparison of electron scattering and proton scattering experiments it is shown that the new mode is largely due to the orbital motion of protons with respect to neutrons. Thirdly, taking the nucleus 164 Dy as an example, g-factors and effective boson charges of the M1-, E2- and M3 IBA transition operators, respectively, are studied. The F-scalar magnetic octupol g-factor Ω S is derived for the first time. Finally, the distribution of M1 strength in 156 Gd will be discussed in the light of recent theoretical calculations. (orig.)

  7. Effect of a neutron skin on collective dipoles modes in nuclei

    International Nuclear Information System (INIS)

    Warner, D.D.; Van Isacker, P.; Nagarajan, M.A.

    1992-01-01

    One of the principal motivations for accelerated radioactive beams is to probe nuclear structure at the limits of nuclear stability. For neutron-rich nuclei, an indication of the new phenomena which may occur has already appeared, in the guise of the neutron halo discovered in very light nuclei. More generally, a steadily increasing neutron skin thickness is expected as the neutron excess increases. The presence of such a mantle of dominantly neutron matter will then particularly affect the properties of collective modes involving the out-of-phase motion of neutrons and protons. This paper explores the effect of the neutron skin thickness on the isovector M1 and E1 modes in medium and heavy mass nuclei. A simple model is used, couched in terms of classical oscillations of neutron and proton densities. The treatment includes the open-quotes pygmyclose quotes E1 mode, which corresponds to motion of the core against the loosely-bound neutrons in the mantle and predicts a significant lowering of this mode, even at relatively modest values of the skin thickness

  8. A sum rule description of giant resonances at finite temperature

    International Nuclear Information System (INIS)

    Meyer, J.; Quentin, P.; Brack, M.

    1983-01-01

    A generalization of the sum rule approach to collective motion at finite temperature is presented. The m 1 and msub(-1) sum rules for the isovector dipole and the isoscalar monopole electric modes have been evaluated with the modified SkM force for the 208 Pb nucleus. The variation of the resulting giant resonance energies with temperature is discussed. (orig.)

  9. Giant thermo-optical relaxation oscillations in millimeter-size whispering gallery mode disk resonators.

    Science.gov (United States)

    Diallo, Souleymane; Lin, Guoping; Chembo, Yanne K

    2015-08-15

    In this Letter, we show that giant thermo-optical oscillations can be triggered in millimeter (mm)-size whispering gallery mode (WGM) disk resonators when they are pumped by a resonant continuous-wave laser. Our resonator is an ultrahigh-Q barium fluoride cavity that features a positive thermo-optic coefficient and a negative thermo-elastic coefficient. We demonstrate for the first time, to our knowledge, that the complex interplay between these two thermic coefficients and the intrinsic Kerr nonlinearity yields very sharp slow-fast relaxation oscillations with a slow timescale that can be exceptionally large, typically of the order of 1 s. We use a time-domain model to gain understanding into this instability, and we find that both the experimental and theoretical results are in excellent agreement. The understanding of these thermal effects is an essential requirement for every WGM-related application and our study demonstrates that even in the case of mm-size resonators, such effects can still be accurately analyzed using nonlinear time-domain models.

  10. Suppression of nonlinear frequency-sweeping of resonant interchange modes in a magnetic dipole with applied radio frequency fields

    International Nuclear Information System (INIS)

    Maslovsky, D.; Levitt, B.; Mauel, M. E.

    2003-01-01

    Interchange instabilities excited by energetic electrons trapped by a magnetic dipole nonlinearly saturate and exhibit complex, coherent spectral characteristics and frequency sweeping [H. P. Warren and M. E. Mauel, Phys. Plasmas 2, 4185 (1995)]. When monochromatic radio frequency (rf) fields are applied in the range of 100-1000 MHz, the saturation behavior of the interchange instability changes dramatically. For applied fields of sufficient intensity and pulse-length, coherent interchange fluctuations are suppressed and frequency sweeping is eliminated. When rf fields are switched off, coherent frequency sweeping reappears. Since low frequency interchange instabilities preserve the electron's first and second adiabatic invariants, these observations can be interpreted as resulting from nonlinear resonant wave-particle interactions described within a particle phase-space, (ψ,φ), comprised of the third adiabatic invariant and the azimuthal angle. Self-consistent numerical simulation is used to study (1) the nonlinear development of the instability, (2) the radial mode structure of the interchange instability, and (3) the suppression of frequency sweeping. When the applied rf heating is modeled as an 'rf collisionality', the simulation reproduces frequency sweeping suppression and suggests an explanation for the observations that is consistent with Berk and co-workers [H. L. Berk et al., Phys. Plasmas 6, 3102 (1999)

  11. STRUCTURAL GLITCHES NEAR THE CORES OF RED GIANTS REVEALED BY OSCILLATIONS IN G-MODE PERIOD SPACINGS FROM STELLAR MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, M. S.; Avelino, P. P. [Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, 4150-762 Porto (Portugal); Stello, D. [Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006 (Australia); Christensen-Dalsgaard, J. [Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Townsend, R. H. D., E-mail: mcunha@astro.up.pt [Department of Astronomy, University of Wisconsin–Madison, 2535 Sterling Hall, 475 N. Charter Street, Madison, WI 53706 (United States)

    2015-06-01

    With recent advances in asteroseismology it is now possible to peer into the cores of red giants, potentially providing a way to study processes such as nuclear burning and mixing through their imprint as sharp structural variations—glitches—in the stellar cores. Here we show how such core glitches can affect the oscillations we observe in red giants. We derive an analytical expression describing the expected frequency pattern in the presence of a glitch. This formulation also accounts for the coupling between acoustic and gravity waves. From an extensive set of canonical stellar models we find glitch-induced variation in the period spacing and inertia of non-radial modes during several phases of red giant evolution. Significant changes are seen in the appearance of mode amplitude and frequency patterns in asteroseismic diagrams such as the power spectrum and the échelle diagram. Interestingly, along the red giant branch glitch-induced variation occurs only at the luminosity bump, potentially providing a direct seismic indicator of stars in that particular evolution stage. Similarly, we find the variation at only certain post-helium-ignition evolution stages, namely, in the early phases of helium core burning and at the beginning of helium shell burning, signifying the asymptotic giant branch bump. Based on our results, we note that assuming stars to be glitch-free, while they are not, can result in an incorrect estimate of the period spacing. We further note that including diffusion and mixing beyond classical Schwarzschild could affect the characteristics of the glitches, potentially providing a way to study these physical processes.

  12. Asteroseismology of Red-Giant Stars: Mixed Modes, Differential Rotation, and Eccentric Binaries

    Science.gov (United States)

    Beck, Paul G.

    2013-12-01

    Astronomers are aware of rotation in stars since Galileo Galilei attributed the movement of sunspots to rotation of the Sun in 1613. In contrast to the Sun, whose surface can be resolved by small telescopes or even the (protected) eye, we detect stars as point sources with no spatial information. Numerous techniques have been developed to derive information about stellar rotation. Unfortunately, most observational data allow only for the surface rotational rate to be inferred. The internal rotational profile, which has a great effect on the stellar structure and evolution, remains hidden below the top layers of the star - the essential is hidden to the eyes. Asteroseismology allows us to "sense" indirectly deep below the stellar surface. Oscillations that propagate through the star provide information about the deep stellar interiors while they also distort the stellar surface in characteristic patterns leading to detectable brightness or velocity variations. Also, certain oscillation modes are sensitive to internal rotation and carry information on how the star is spinning deep inside. Thanks to the unprecedented quality of NASA's space telescope Kepler, numerous detailed observations of stars in various evolutionary stages are available. Such high quality data allow that for many stars, rotation can not only be constrained from surface rotation, but also investigated through seismic studies. The work presented in this thesis focuses on the oscillations and internal rotational gradient of evolved single and binary stars. It is shown that the seismic analysis can reach the cores of oscillating red-giant stars and that these cores are rapidly rotating, while nested in a slowly rotating convective envelope.

  13. Giant enhancement of reflectance due to the interplay between surface confined wave modes and nonlinear gain in dielectric media.

    Science.gov (United States)

    Kim, Sangbum; Kim, Kihong

    2017-12-11

    We study theoretically the interplay between the surface confined wave modes and the linear and nonlinear gain of the dielectric layer in the Otto configuration. The surface confined wave modes, such as surface plasmons or waveguide modes, are excited in the dielectric-metal bilayer by obliquely incident p waves. In the purely linear case, we find that the interplay between linear gain and surface confined wave modes can generate a large reflectance peak with its value much greater than 1. As the linear gain parameter increases, the peak appears at smaller incident angles, and the associated modes also change from surface plasmons to waveguide modes. When the nonlinear gain is turned on, the reflectance shows very strong multistability near the incident angles associated with surface confined wave modes. As the nonlinear gain parameter is varied, the reflectance curve undergoes complicated topological changes and sometimes displays separated closed curves. When the nonlinear gain parameter takes an optimally small value, a giant amplification of the reflectance by three orders of magnitude occurs near the incident angle associated with a waveguide mode. We also find that there exists a range of the incident angle where the wave is dissipated rather than amplified even in the presence of gain. We suggest that this can provide the basis for a possible new technology for thermal control in the subwavelength scale.

  14. Spatial and seasonal responses of precipitation in the Ganges and Brahmaputra river basins to ENSO and Indian Ocean dipole modes: implications for flooding and drought

    Science.gov (United States)

    Pervez, M. S.; Henebry, G. M.

    2014-02-01

    We evaluated the spatial and temporal responses of precipitation in the basins as modulated by the El Niño Southern Oscillation (ENSO) and Indian Ocean (IO) dipole modes using observed precipitation records at 43 stations across the Ganges and Brahmaputra basins from 1982 to 2010. Daily observed precipitation records were extracted from Global Surface Summary of the Day dataset and spatial and monthly anomalies were computed. The anomalies were averaged for the years influenced by climate modes combinations. Occurrences of El Niño alone significantly reduced (60% and 88% of baseline in the Ganges and Brahmaputra basins, respectively) precipitation during the monsoon months in the northwestern and central Ganges basin and across the Brahmaputra basin. In contrast, co-occurrence of La Niña and a positive IO dipole mode significantly enhanced (135% and 160% of baseline, respectively) precipitation across both basins. During the co-occurrence of neutral phases in both climate modes (occurring 13 out of 28 yr), precipitation remained below average to average in the agriculturally extensive areas of Haryana, Uttar Pradesh, Bihar, eastern Nepal, and the Rajshahi district in Bangladesh in the Ganges basin and northern Bangladesh, Meghalaya, Assam, and Arunachal Pradesh in the Brahmaputra basin. This pattern implies that a regular water deficit is likely in these areas with implications for the agriculture sector due to its reliance on consistent rainfall for successful production. Major flooding and drought occurred as a consequence of the interactive effects of the ENSO and IO dipole modes, with the sole exception of extreme precipitation and flooding during El Niño events. This observational analysis will facilitate well informed decision making in minimizing natural hazard risks and climate impacts on agriculture, and supports development of strategies ensuring optimized use of water resources in best management practice under changing climate.

  15. Fast core rotation in red-giant stars as revealed by gravity-dominated mixed modes

    NARCIS (Netherlands)

    Beck, P.G.; Montalban, J.; Kallinger, T.; De Ridder, J.; Aerts, C.; García, R.A.; Hekker, S.; Dupret, M.-A.; Mosser, B.; Eggenberger, P.; Stello, D.; Elsworth, Y.; Frandsen, S.; Carrier, F.; Hillen, M.; Gruberbauer, M.; Christensen-Dalsgaard, J.; Miglio, A.; Valentini, M.; Bedding, T.R.; Kjeldsen, H.; Girouard, F.R.; Hall, J.R.; Ibrahim, K.A.

    2012-01-01

    When the core hydrogen is exhausted during stellar evolution, the central region of a star contracts and the outer envelope expands and cools, giving rise to a red giant. Convection takes place over much of the star's radius. Conservation of angular momentum requires that the cores of these stars

  16. Giant Gold Nanowire Vesicle-Based Colorimetric and SERS Dual-Mode Immunosensor for Ultrasensitive Detection of Vibrio parahemolyticus.

    Science.gov (United States)

    Guo, Zhiyong; Jia, Yaru; Song, Xinxin; Lu, Jing; Lu, Xuefei; Liu, Baoqing; Han, Jiaojiao; Huang, Youju; Zhang, Jiawei; Chen, Tao

    2018-05-15

    Conventional methods for the detection of Vibrio parahemolyticus (VP) usually need tedious, labor-intensive processes, and have low sensitivity, which further limits their practical applications. Herein, we developed a simple and efficient colorimetry and surface-enhanced Raman scattering (SERS) dual-mode immunosensor for sensitive detection of VP, by employing giant Au vesicles with anchored tiny gold nanowires (AuNW) as a smart probe. Due to the larger specific surface and special hollow structure of giant Au vesicles, silver staining would easily lead to vivid color change for colorimetric analysis and further amplify SERS signals. The t-test was further used to determine if two sets of data from colorimetry and SERS were significantly different from each other. The result shows that there was no significant difference between data from the two methods. Two sets of data can mutually validate each other and avoid false positive and negative detection. The designed colorimetry-SERS dual-mode sensor would be very promising in various applications such as food safety inspection, personal healthcare, and on-site environmental monitoring.

  17. A study of beam position diagnostics with beam-excited dipole higher order modes using a downconverter test electronics in third harmonic 3.9 GHz superconducting accelerating cavities at FLASH

    International Nuclear Information System (INIS)

    Zhang, P.; Baboi, N.; Lorbeer, B.; Wamsat, T.; Eddy, N.; Fellenz, B.; Wendt, M.; Jones, R.M.

    2012-08-01

    Beam-excited higher order modes (HOM) in accelerating cavities contain transverse beam position information. Previous studies have narrowed down three modal options for beam position diagnostics in the third harmonic 3.9 GHz cavities at FLASH. Localized modes in the beam pipes at approximately 4.1 GHz and in the fifth cavity dipole band at approximately 9 GHz were found, that can provide a local measurement of the beam position. In contrast, propagating modes in the first and second dipole bands between 4.2 and 5.5 GHz can reach a better resolution. All the options were assessed with a specially designed test electronics built by Fermilab. The aim is to de ne a mode or spectral region suitable for the HOM electronics. Two data analysis techniques are used and compared in extracting beam position information from the dipole HOMs: direct linear regression and singular value decomposition. Current experiments suggest a resolution of 50 m accuracy in predicting local beam position using modes in the fifth dipole band, and a global resolution of 20 m over the complete module. Based on these results we decided to build a HOM electronics for the second dipole band and the fifth dipole band, so that we will have both high resolution measurements for the whole module, and localized measurements for individual cavity. The prototype electronics is being built by Fermilab and planned to be tested in FLASH by the end of 2012.

  18. A study of beam position diagnostics with beam-excited dipole higher order modes using a downconverter test electronics in third harmonic 3.9 GHz superconducting accelerating cavities at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, P. [Manchester Univ. (United Kingdom); Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Baboi, N.; Lorbeer, B.; Wamsat, T. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Eddy, N.; Fellenz, B.; Wendt, M. [Fermi National Accelerator Lab., Batavia, IL (United States); Jones, R.M. [Manchester Univ. (United Kingdom); The Cockcroft Institute, Daresbury (United Kingdom)

    2012-08-15

    Beam-excited higher order modes (HOM) in accelerating cavities contain transverse beam position information. Previous studies have narrowed down three modal options for beam position diagnostics in the third harmonic 3.9 GHz cavities at FLASH. Localized modes in the beam pipes at approximately 4.1 GHz and in the fifth cavity dipole band at approximately 9 GHz were found, that can provide a local measurement of the beam position. In contrast, propagating modes in the first and second dipole bands between 4.2 and 5.5 GHz can reach a better resolution. All the options were assessed with a specially designed test electronics built by Fermilab. The aim is to de ne a mode or spectral region suitable for the HOM electronics. Two data analysis techniques are used and compared in extracting beam position information from the dipole HOMs: direct linear regression and singular value decomposition. Current experiments suggest a resolution of 50 m accuracy in predicting local beam position using modes in the fifth dipole band, and a global resolution of 20 m over the complete module. Based on these results we decided to build a HOM electronics for the second dipole band and the fifth dipole band, so that we will have both high resolution measurements for the whole module, and localized measurements for individual cavity. The prototype electronics is being built by Fermilab and planned to be tested in FLASH by the end of 2012.

  19. 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)

  20. Excitation and photon decay of giant resonances excited by intermediate energy heavy ions

    International Nuclear Information System (INIS)

    Bertrand, F.E.; Beene, J.R.

    1987-01-01

    Inelastic scattering of medium energy heavy ions provides very large cross sections and peak-to-continuum ratios for excitation of giant resonances. For energies above about 50 MeV/nucleon, giant resonances are excited primarily through Coulomb excitation, which is indifferent to isospin, thus providing a good probe for the study of isovector giant resonances. The extremely large cross sections available from heavy ion excitation permit the study of rare decay modes of the giant resonances. In particular, recent measurements have been made of the photon decay of giant resonances following excitation by 22 and 84 MeV/nucleon 17 O projectiles. The singles results at 84 MeV/nucleon yield peak cross sections for the isoscalar giant quadrupole resonance and the isovector giant dipole resonance of approximately 0.8 and 3 barns/sr, respectively. Data on the ground state decay of the isoscalar giant quadrupole and isovector giant dipole resonances are presented and compared with calculations. Decays to low-lying excited states are also discussed. Preliminary results from an experiment to isolate the 208 Pb isovector quadrupole resonance using its gamma decay are presented. 22 refs., 19 figs., 1 tab

  1. Kepler Detected Gravity-Mode Period Spacings in a Red Giant Star

    DEFF Research Database (Denmark)

    Beck, P.G.; Bedding, Timothy R.; Mosser, Benoit

    2011-01-01

    Stellar interiors are inaccessible through direct observations. For this reason, helioseismologists made use of the Sun’s acoustic oscillation modes to tune models of its structure. The quest to detect modes that probe the solar core has been ongoing for decades. We report the detection of mixed...... modes penetrating all the way to the core of an evolved star from 320 days of observations with the Kepler satellite. The period spacings of these mixed modes are directly dependent on the density gradient between the core region and the convective envelope....

  2. ACOL dipoles

    International Nuclear Information System (INIS)

    Vlogaert, J.

    1987-01-01

    This paper describes the general design of ACOL dipoles, including the special injection area dipole. A list of mechanical, electrical and magnetic parameters and results of magnetic measurements are presented. Particular attention is paid to the proximity effects between quadrupoles and dipoles

  3. Kepler detected gravity-mode period spacings in a red giant star

    NARCIS (Netherlands)

    Beck, P.G.; Bedding, T.R.; Mosser, B.; Stello, D.; Garcia, R.A.; Kallinger, T.; Hekker, S.; Elsworth, Y.; Frandsen, S.; Carrier, F.; de Ridder, J.; Aerts, C.; White, T.R.; Huber, D.; Dupret, M. A.; Montalban, J.; Miglio, A.; Noels, A.; Chaplin, W.J.; Kjeldsen, H.; Christensen-Dalsgaard, J.; Gilliland, R.L.; Brown, T.M.; Kawaler, S.D.; Mathur, S.; Jenkins, J.M.

    2011-01-01

    Stellar interiors are inaccessible through direct observations. For this reason, helioseismologists made use of the Sun’s acoustic oscillation modes to tune models of its structure. The quest to detect modes that probe the solar core has been ongoing for decades. We report the detection of mixed

  4. Excitation of transverse dipole and quadrupole modes in a pure ion plasma in a linear Paul trap to study collective processes in intense beams

    Energy Technology Data Exchange (ETDEWEB)

    Gilson, Erik P.; Davidson, Ronald C.; Efthimion, Philip C.; Majeski, Richard; Startsev, Edward A.; Wang, Hua [Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Koppell, Stewart [University of Texas at Austin, Austin, Texas 78712 (United States); Talley, Matthew [Brigham Young University, Provo, Utah 84602 (United States)

    2013-05-15

    Transverse dipole and quadrupole modes have been excited in a one-component cesium ion plasma trapped in the Paul Trap Simulator Experiment (PTSX) in order to characterize their properties and understand the effect of their excitation on equivalent long-distance beam propagation. The PTSX device is a compact laboratory Paul trap that simulates the transverse dynamics of a long, intense charge bunch propagating through an alternating-gradient transport system by putting the physicist in the beam's frame of reference. A pair of arbitrary function generators was used to apply trapping voltage waveform perturbations with a range of frequencies and, by changing which electrodes were driven with the perturbation, with either a dipole or quadrupole spatial structure. The results presented in this paper explore the dependence of the perturbation voltage's effect on the perturbation duration and amplitude. Perturbations were also applied that simulate the effect of random lattice errors that exist in an accelerator with quadrupole magnets that are misaligned or have variance in their field strength. The experimental results quantify the growth in the equivalent transverse beam emittance that occurs due to the applied noise and demonstrate that the random lattice errors interact with the trapped plasma through the plasma's internal collective modes. Coherent periodic perturbations were applied to simulate the effects of magnet errors in circular machines such as storage rings. The trapped one component plasma is strongly affected when the perturbation frequency is commensurate with a plasma mode frequency. The experimental results, which help to understand the physics of quiescent intense beam propagation over large distances, are compared with analytic models.

  5. Study of a new magnetic dipole mode in the heavy deformed nuclei 154Sm, 156Gd, 158Gd, 164Dy, 168Er, and 174Yb by high-resolution electron spectroscopy

    International Nuclear Information System (INIS)

    Bohle, D.

    1985-01-01

    By inelastic electron scattering with high energy resolution a new magnetic dipole mode in heavy, deformed nuclei could be detected. For this the nuclei 154 Sm, 156 Gd, 158 Gd, 164 Dy, 168 Er, and 174 Yb were studied at the Darmstadt electron linear accelerator (DALINAC) at small momentum transfer q ≤ 0.6 fm -1 and low excitation energies. A collective magnetic dipole excitation could be discovered in all nuclei at an excitation energy of E x ≅ 66 δA -1/3 MeV whereby δ means the mass deformation. The transition strength extends in the mean to B(M1)↑ ≅ 1.3 μ N 2 . A systematic study of the nucleus 156 Gd yielded hints to a strong fragmentation of the magnetic dipole strength. A comparison of electron scattering, proton scattering, and nuclear resonance fluorescence experiments shows that the new mode is a pure orbital mode. (orig./HSI) [de

  6. Quantum calculation of dipole excitation in fusion reaction

    International Nuclear Information System (INIS)

    Simenel, C.; Chomaz, Ph.; De France, G.

    2000-01-01

    The excitation of the giant dipole resonance by fusion is studied with N/Z asymmetry in the entrance channel. The TDHF solution exhibits a strong dipole vibration which can be associated with a giant vibration along the main axis of a fluctuating prolate shape. The consequences on the gamma-ray emission from hot compound nuclei are discussed. (author)

  7. Double giant resonances in time-dependent relativistic mean-field theory

    International Nuclear Information System (INIS)

    Ring, P.; Podobnik, B.

    1996-01-01

    Collective vibrations in spherical nuclei are described in the framework of time-dependent relativistic mean-field theory (RMFT). Isoscalar quadrupole and isovector dipole oscillations that correspond to giant resonances are studied, and possible excitations of higher modes are investigated. We find evidence for modes which can be interpreted as double resonances. In a quantized RMFT they correspond to two-phonon states. (orig.)

  8. Tailoring surface plasmon resonance and dipole cavity plasmon modes of scattering cross section spectra on the single solid-gold/gold-shell nanorod

    International Nuclear Information System (INIS)

    Chou Chau, Yuan-Fong; Lim, Chee Ming; Kumara, N. T. R. N.; Yoong, Voo Nyuk; Lee, Chuanyo; Huang, Hung Ji; Lin, Chun-Ting; Chiang, Hai-Pang

    2016-01-01

    Tunable surface plasmon resonance (SPR) and dipole cavity plasmon modes of the scattering cross section (SCS) spectra on the single solid-gold/gold-shell nanorod have been numerically investigated by using the finite element method. Various effects, such as the influence of SCS spectra under x- and y-polarizations on the surface of the single solid-gold/gold-shell nanorod, are discussed in detail. With the single gold-shell nanorod, one can independently tune the relative SCS spectrum width by controlling the rod length and rod diameter, and the surface scattering by varying the shell thickness and polarization direction, as well as the dipole peak energy. These behaviors are consistent with the properties of localized SPRs and offer a way to optically control and produce selected emission wavelengths from the single solid-gold/gold-shell nanorod. The electric field and magnetic distributions provide us a qualitative idea of the geometrical properties of the single solid-gold/gold-shell nanorod on plasmon resonance.

  9. Isoscalar giant resonances

    Energy Technology Data Exchange (ETDEWEB)

    Youngblood, D. H. [Texas A and M Univ., College Station (USA). Cyclotron Inst.; Ikegami, H.; Muraoka, M. [eds.

    1980-01-01

    The current status of the knowledges of giant quadrupole resonance (GQR), low energy octupole resonance (LEOR), and giant monopole resonance (GMR), is described. In the lowest order of multipole resonance, both isoscalar and isovector modes can occur. The characteristics of the GQR in light nuclei are apparent in the experimental result for Mg-24. All of the isoscalar E2 strength are known in Mg-24. The Goldhaber-Teller model is preferred over the Steinwedel-Jensen model for the giant dipole resonance (GDR) transition density. A few interesting and puzzling features have been seen in Pb-208. There is some conflict between inelastic alpha and electron scatterings. About LEOR, the RPA calculation of Liu and Brown was compared to the data for 3/sup -/ strength in Ca-40, Zr-90 and Pb-208. The calculation was employed the residual interaction of the Skyrme type. The agreement in Zr-90 was excellent. The effect of quadrupole deformation on the LEOR in Sm isotopes was large. The inelastic alpha scattering data on Al-27, Ca-40, Ti-48, Ni-58, Zn-64 and 66, Zr-90, Sn-116, 118, 120 and 124, Sm-144, 148 and 154, and Pb-208 were utilized in order to identify the GMR, and the GMR parameters were obtained. The GMR exhausting a large fraction of the sum rule was apparent in the nuclei with mass larger than 90. The splitting of the GDR and the broadening of the GQR in permanently deformed nuclei were established. The splitting of GMR was seen in Sm-154. The studies with heavy ions are also described.

  10. Dipole resonances in light neutron-rich nuclei studied with time-dependent calculations of antisymmetrized molecular dynamics

    International Nuclear Information System (INIS)

    Kanada-En'yo, Y.; Kimura, M.

    2005-01-01

    To study isovector dipole responses of neutron-rich nuclei, we applied a time-dependent method of antisymmetrized molecular dynamics. The dipole resonances in Be, B, and C isotopes were investigated. In 10 Be, 15 B, and 16 C, collective modes of the vibration between a core and valence neutrons cause soft resonances at the excitation energy E x =10-15 MeV below the giant dipole resonance (GDR). In 16 C, we found that a remarkable peak at E x =14 MeV corresponds to the coherent motion of four valence neutrons against a 12 C core, whereas the GDR arises in the E x >20 MeV region because of vibration within the core. In 17 B and 18 C, the dipole strengths in the low-energy region decline compared with those in 15 B and 16 C. We also discuss the energy-weighted sum rule for the E1 transitions

  11. Excitation of giant resonances in heavy ion collisions

    International Nuclear Information System (INIS)

    Kuehn, W.

    1991-01-01

    Introduction: What are Giant Resonances? General Features of Giant Resonances, Macroscopic Description and Classification, Basic Excitation Mechanisms, Decay Modes, Giant Resonances Built on Excited States, Relativistic Coulomb Excitation of Giant Resonances, Experimental Situation. (orig.)

  12. Analytical expression of giant Goos-Hänchen shift in terms of proper and improper modes in waveguide structures with arbitrary refractive index profile.

    Science.gov (United States)

    Alishahi, Fatemeh; Mehrany, Khashayar

    2010-06-01

    We analytically relate the giant Goos-Hänchen shift, observed at the interface of a high refractive index prism and a waveguide structure with an arbitrary refractive index profile, to the spatial resonance phenomenon. The proximity effect of the high refractive index prism on modal properties of the waveguide is discussed, and the observed shift is expressed in terms of proper and improper electromagnetic modes supported by the waveguide with no prism. The transversely increasing improper modes are shown playing an increasingly important role as the high refractive index prism comes closer to the waveguide.

  13. Recent Results From Skyrme-TDHF: Giant Resonances and Collisions

    International Nuclear Information System (INIS)

    Stevenson, Paul D.

    2007-01-01

    Using fully three-dimensional Time-Dependent Hartree-Fock with Skyrme forces allows one to explore small and large amplitude collective motion in nuclei using only an effective interaction fitted to ground state and nuclear matter properties as input. In this talk, results are presented for TDHF calculations of giant resonances and nuclear collisions. We examine deformation splitting of the giant dipole resonance on ground and excited intrinsic superdeformed states, showing the interplay between Landau splitting and deformation splitting, including effects of triaxiality[1]. In the case of giant monopole resonances, isospin-mixing is examined, showing that the isovector and isoscalar parts of strength functions are strongly coupled [2]. The role of absorption in the TDHF approach to linear and nonlinear regimes is examined[3]. Calculations of nuclear collisions are also explored, showing that the effects of fully relaxed symmetry produce new modes of energy loss not found in previous calculations [4]. (Author)

  14. Isotopic effect giant resonances

    International Nuclear Information System (INIS)

    Buenerd, M.; Lebrun, D.; Martin, P.; Perrin, G.; Saintignon, P. de; Chauvin, J.; Duhamel, G.

    1981-10-01

    The systematics of the excitation energy of the giant dipole, monopole, and quadrupole resonances are shown to exhibit an isotopic effect. For a given element, the excitation energy of the transition decreases faster with the increasing neutron number than the empirical laws fitting the overall data. This effect is discussed in terms of the available models

  15. Deformations and Displacements of the LHC Superconducting Dipoles Induced by Standard and Non-Standard Operational Modes

    CERN Document Server

    La China, M; Gubello, G; Scandale, Walter

    2004-01-01

    A full-scale and fully-instrumented working model of the LHC lattice cell has been tested at CERN between March and December 2002. Aside of the current, pressure and temperature sensors, controlled by an industrial supervision system, a novel device has been set to monitor magnet positions with respect to the surrounding cryostat. The series of operating modes to test cryogenics, current leads and quench recovery electronics offered the chance to investigate potentially harmful deformations of the superconducting structure. In this paper we present a survey of displacements and deformations experienced by the LHC cell magnets during thermal cycles, current ramps and resistive transitions. Although the system complexity prevented from complete modeling, a preliminary phenomena explanation is given.

  16. The splitting of giant multipole states of deformed nuclei

    International Nuclear Information System (INIS)

    Suzuki, T.; Rowe, D.J.

    1977-01-01

    A vibrating potential model is applied to deformed nuclei with a deformed harmonic oscillator potential in order to discuss the splitting of isoscalar giant quadrupole states. Eigenfrequencies of the collective states are estimated to be √2ω(1 - delta/3), √2ω(1 - delta/6) and √2ω(1 + delta/3) for K = 0 + ,1 + and 2 + modes, respectively. The splitting of isovector dipole and isovector quadrupole states is also studied according to a schematic model as proposed by Bohr and Mottelson. It is shown that isovector dipole states are split, as in a hydrodynamic model, while isovector quadrupole states with the same scaling factors as those of isocalar quadrupole modes. (Auth.)

  17. The dipole response of {sup 132}Sn

    Energy Technology Data Exchange (ETDEWEB)

    Schrock, Philipp; Aumann, Thomas; Johansen, Jacob; Schindler, Fabia [IKP, TU Darmstadt (Germany); Boretzky, Konstanze [GSI Helmholtzzentrum (Germany); Rossi, Dominic [Michigan State University (United States); Collaboration: R3B-Collaboration

    2015-07-01

    The Isovector Giant Dipole Resonance (IVGDR) is a well-known collective excitation in which all protons oscillate against all neutrons of a nucleus. In neutron-rich nuclei an additional low-lying dipole excitation occurs, often denoted as Pygmy Dipole Resonance (PDR). To study the PDR in exotic Sn-isotopes, an experiment has been successfully performed with the upgraded R{sup 3}B-LAND setup at GSI. The complete-kinematics measurement of all reaction participants allows for the reconstuction of the excitation energy and, hence, the extraction of the dipole strength. Presented are the main features of the experiment, the analysis concept and the current status of the analysis of the dipole response of the doubly-magic isotope {sup 132}Sn.

  18. Electric-dipole absorption resonating with longitudinal optical phonon-plasmon system and its effect on dispersion relations of interface phonon polariton modes in metal/semiconductor-stripe structures

    Science.gov (United States)

    Sakamoto, Hironori; Takeuchi, Eito; Yoshida, Kouki; Morita, Ken; Ma, Bei; Ishitani, Yoshihiro

    2018-01-01

    Interface phonon polaritons (IPhPs) in nano-structures excluding metal components are thoroughly investigated because they have lower loss in optical emission or absorption and higher quality factors than surface plasmon polaritons. In previous reports, it is found that strong infrared (IR) absorption is based on the interaction of p-polarized light and materials, and the resonance photon energy highly depends on the structure size and angle of incidence. We report the optical absorption by metal/semiconductor (bulk-GaAs and thin film-AlN)-stripe structures in THz to mid-IR region for the electric field of light perpendicular to the stripes, where both of s- and p-polarized light are absorbed. The absorption resonates with longitudinal optical (LO) phonon or LO phonon-plasmon coupling (LOPC) modes, and thus is independent of the angle of incidence or structure size. This absorption is attributed to the electric dipoles by the optically induced polarization charges at the metal/semiconductor, heterointerfaces, or interfaces of high electron density layers and depression ones. The electric permittivity is modified by the formation of these dipoles. It is found to be indispensable to utilize our form of altered permittivity to explain the experimental dispersion relations of metal/semiconductor-IPhP and SPhP in these samples. This analysis reveals that the IPhPs in the stripe structures of metal/AlN-film on a SiC substrate are highly confined in the AlN film, while the permittivity of the structures of metal/bulk-GaAs is partially affected by the electric-dipoles. The quality factors of the electric-dipole absorption are found to be 42-54 for undoped samples, and the value of 62 is obtained for Al/AlN-IPhP. It is thought that metal-contained structures are not obstacles to mode energy selectivity in phonon energy region of semiconductors.

  19. Electric Dipole States and Time Reversal Violation in Nuclei

    International Nuclear Information System (INIS)

    Auerbach, N.

    2016-01-01

    The nuclear Schiff moment is essential in the mechanism that induces a parity and time reversal violation in the atom. In this presentation we explore theoretically the properties and systematics of the isoscalar dipole in nuclei with the emphasis on the low-energy strength and the inverse energy weighted sum which determines the Schiff moment. We also study the influence of the isovector dipole strength distribution on the Schiff moment. The influence of a large neutron excess in nuclei is examined. The centroid energies of the isoscalar giant resonance (ISGDR) and the overtone of the isovector giant dipole resonance (OIVGDR) are given for a range of nuclei. (paper)

  20. Isoscalar compression modes in relativistic random phase approximation

    International Nuclear Information System (INIS)

    Ma, Zhong-yu; Van Giai, Nguyen.; Wandelt, A.; Vretenar, D.; Ring, P.

    2001-01-01

    Monopole and dipole compression modes in nuclei are analyzed in the framework of a fully consistent relativistic random phase approximation (RRPA), based on effective mean-field Lagrangians with nonlinear meson self-interaction terms. The large effect of Dirac sea states on isoscalar strength distribution functions is illustrated for the monopole mode. The main contribution of Fermi and Dirac sea pair states arises through the exchange of the scalar meson. The effect of vector meson exchange is much smaller. For the monopole mode, RRPA results are compared with constrained relativistic mean-field calculations. A comparison between experimental and calculated energies of isoscalar giant monopole resonances points to a value of 250-270 MeV for the nuclear matter incompressibility. A large discrepancy remains between theoretical predictions and experimental data for the dipole compression mode

  1. Spreading effects on the isovector dipole strength distribution in 208Pb

    International Nuclear Information System (INIS)

    Adachi, S.; Nguyen van Giai

    1984-01-01

    There is seemingly a difficulty with all Hartree-Fock RPA calculations to describe correctly the distribution of dipole strength in heavy nuclei above the giant dipole region. We investigate in a consistent framework the effects of damping into more complex configurations. We show that in 208 Pb, this damping leads to a smooth distribution at higher energies while it gives a satisfactory description of the spreading width of the giant dipole resonance. (orig.)

  2. NON-RADIAL OSCILLATIONS IN M-GIANT SEMI-REGULAR VARIABLES: STELLAR MODELS AND KEPLER OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Stello, Dennis; Compton, Douglas L.; Bedding, Timothy R.; Kiss, Laszlo L.; Bellamy, Beau [Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006 (Australia); Christensen-Dalsgaard, Jørgen; Kjeldsen, Hans [Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); García, Rafael A. [Laboratoire AIM, CEA/DSM-CNRS, Université Paris 7 Diderot, IRFU/SAp, Centre de Saclay, F-91191 Gif-sur-Yvette (France); Mathur, Savita, E-mail: stello@physics.usyd.edu.au [Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301 (United States)

    2014-06-10

    The success of asteroseismology relies heavily on our ability to identify the frequency patterns of stellar oscillation modes. For stars like the Sun this is relatively easy because the mode frequencies follow a regular pattern described by a well-founded asymptotic relation. When a solar-like star evolves off the main sequence and onto the red giant branch its structure changes dramatically, resulting in changes in the frequency pattern of the modes. We follow the evolution of the adiabatic frequency pattern from the main sequence to near the tip of the red giant branch for a series of models. We find a significant departure from the asymptotic relation for the non-radial modes near the red giant branch tip, resulting in a triplet frequency pattern. To support our investigation we analyze almost four years of Kepler data of the most luminous stars in the field (late K and early M type) and find that their frequency spectra indeed show a triplet pattern dominated by dipole modes even for the most luminous stars in our sample. Our identification explains previous results from ground-based observations reporting fine structure in the Petersen diagram and sub-ridges in the period-luminosity diagram. Finally, we find ''new ridges'' of non-radial modes with frequencies below the fundamental mode in our model calculations, and we speculate they are related to f modes.

  3. The Droplet model of the Giant Fipole Resonance

    International Nuclear Information System (INIS)

    Myers, W.D.; Kodama, T.; El-Jaick, L.J.; Hilf, E.R.

    1976-10-01

    The nuclear Giant Dipole Resonance (GDR) energies are calculated using a macroscopic hydronamical model with two new features. The motion is treated as a combination of the usual Goldhaber-Teller (GT) and Steinwedel-Jensen (SJ) modes, and the restoring forces are all calculated using the Droplet Model. The A dependence of the resonance energies is well reproduced without any adjustable parameters, and the measured magnitude of the energies serves to fix the value of the effective mass m* used in the theory. The GDR is found to consist mainly of a GT-type motion with the SJ-mode becoming more important for heavy nuclei. The width P of the GDR is also estimated on the basis of an expression for one-body damping [pt

  4. Plasma confinement in a magnetic dipole

    International Nuclear Information System (INIS)

    Kesner, J.; Bromberg, L.; Garnier, D.; Mauel, M.

    1999-01-01

    A dipole fusion confinement device is stable to MHD interchange and ballooning modes when the pressure profile is sufficiently gentle. The plasma can be confined at high beta, is steady state and disruption free. Theory indicates that when the pressure gradient is sufficiently gentle to satisfy MHD requirements drift waves will also be stable. The dipole approach is particularly applicable for advanced fuels. A new experimental facility is presently being built to test the stability and transport properties of a dipole-confined plasma. (author)

  5. Plasma confinement in a magnetic dipole

    International Nuclear Information System (INIS)

    Kesner, J.; Bromberg, L.; Garnier, D.; Mauel, M.

    2001-01-01

    A dipole fusion confinement device is stable to MHD interchange and ballooning modes when the pressure profile is sufficiently gentle. The plasma can be confined at high beta, is steady state and disruption free. Theory indicates that when the pressure gradient is sufficiently gentle to satisfy MHD requirements drift waves will also be stable. The dipole approach is particularly applicable for advanced fuels. A new experimental facility is presently being built to test the stability and transport properties of a dipole-confined plasma. (author)

  6. Hadron excitation of giant resonances

    International Nuclear Information System (INIS)

    Morsch, H.-P.

    1985-01-01

    A review is given on giant resonance studies in heavy nuclei using scattering of different hadronic probes. Concerning isoscalar giant resonances compression modes are discussed with the possibility to obtain more detailed structure information. From detailed studies of α scattering the distribution of isoscalar strengths of multipolarity up to L=6 was obtained. Some recent aspects of heavy ion excitation of collective modes are mentioned. The possibility to study isovector giant resonances in hadron charge exchange reactions is discussed. Finally, a comparison is made between α and 200 MeV proton scattering from which isoscalar and spin-isospin continuum response are extracted. (orig.)

  7. Dipole Correlation of the Electronic Structures of theConformations of Water Molecule Evolving Through theNormal Modes of Vibrations Between Angular (C2v to Linear(D∝h Shapes

    Directory of Open Access Journals (Sweden)

    Arindam Chakraborty

    2006-03-01

    Full Text Available In order to settle the issue of equivalence or non-equivalence of the two lone pairsof electrons on oxygen atom in water molecule, a quantum chemical study of the dipolecorrelation of the electronic structure of the molecule as a function of conformationsgenerated following the normal modes of vibrations between the two extremeconformations, C2v (∠HOH at 90o and D∝h (∠HOH at 180o, including the equilibrium one,has been performed. The study invokes quantum mechanical partitioning of moleculardipoles into bond moment and lone pair moment and localization of delocalized canonicalmolecular orbitals, CMO’s into localized molecular orbitals, LMO’s. An earlier suggestion,on the basis of photoelectron spectroscopy, that one lone pair is in p-type and the other is ins-type orbital of O atom of water molecule at its equilibrium shape, and also the qualitative“Squirrel Ears” structure are brought under serious scrutiny. A large number ofconformations are generated and the charge density matrix, dipole moment of eachconformation is computed in terms of the generated canonical molecular orbitals, CMO’sand then Sinanoğlu’s localization method is invoked to localize the CMO’s of eachconformation and the quantum mechanical hybridizations of all the bonds and lone pairs onO center are evaluated in terms of the localized molecular orbitals. Computed datademonstrate that the electronic structures i.e. two bond pairs and two lone pairs and itshybridization status of all conformations of water molecule are straightforward in terms ofthe LMO’s. It is further revealed that the pattern of orbital hybridization changescontinuously as a function of evolution of molecular shape. The close analysis of thegenerated LMO’s reveals that one lone pair is accommodated in a pure p orbital and anotherlone pair is in a hybrid

  8. Giant grains

    International Nuclear Information System (INIS)

    Leitch-Devlin, M.A.; Millar, T.J.; Williams, D.A.

    1976-01-01

    Infrared observations of the Orion nebula have been interpreted by Rowan-Robinson (1975) to imply the existence of 'giant' grains, radius approximately 10 -2 cm, throughout a volume about a parsec in diameter. Although Rowan-Robinson's model of the nebula has been criticized and the presence of such grains in Orion is disputed, the proposition is accepted, that they exist, and in this paper situations in which giant grains could arise are examined. It is found that, while a giant-grain component to the interstellar grain density may exist, it is difficult to understand how giant grains arise to the extent apparently required by the Orion nebula model. (Auth.)

  9. Prototype and proposed ISABELLE dipoles

    International Nuclear Information System (INIS)

    McInturff, A.D.; Sampson, W.B.; Robins, K.E.; Dahl, P.F.; Damm, R.

    1977-01-01

    Data are presented on the latest dipole prototypes to update the operational parameters possible for ISABELLE. This data base will constantly expand until the start of construction of the storage rings. The data will include field quality, stray field magnitudes, quench temperature and propagation times, protection capabilities singly and in multiple units, maximum central fields obtained and training behavior. Performance of the dipoles versus temperature and mode of refrigeration will be discussed. The single layer cosine theta turns distribution coils' parameters are better than those required for the operation of the 200 x 200 GeV version of ISABELLE. The double layer prototype has exceeded the magnetic field performance and two dimensional quality of field needed for the 400 x 400 GeV version of ISABELLE

  10. ZZ-CENPL, Chinese Evaluated Nuclear Parameter Library. ZZ CENPL-DLS, Discrete Level Schemes and Gamma Branching Ratios Library; ZZ CENPL-FBP, Fission Barrier Parameter Library; ZZ CENPL-GDRP, Giant Dipole Resonance Parameter Library; ZZ CENPL-NLD, Nuclear Level Density Parameter Library; ZZ CENPL-MCC, Nuclear Ground State Atomic Masses Library; ZZ CENPL-OMP, Optical Model Parameter Library

    International Nuclear Information System (INIS)

    Su Zongdi

    1995-01-01

    Description of program or function: CENPL - GDRP (Giant Dipole Resonance Parameters for Gamma-Ray): - Format: special format described in documentation; - Nuclides: V, Mn, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Rb, Sr, Y, Zr, Nb, Mo, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, I, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Ho, Er, Lu, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, Th, U, Np, Pu. - Origin: Experimental values offered by S.S. Dietrich and B.L. Berman. CENPL - FBP (Fission Barrier Parameter Sub-Library): - Format: special format described in documentation; - Nuclides: (1) 51 nuclei region from Th-230 to Cf-255, (2) 46 nuclei region from Th-229 to Cf-253, (3) 24 nuclei region from Pa-232 to Cf-253; - Origin: (1) Lynn, (2) Analysis of experimental data by Back et al., (3) Ohsawa. CENPL - DLS (Discrete level scheme and branch ratio of gamma decay: - Format: Special format described in documentation; - Origin: ENSDF - BNL. CENPL - NLD (Nuclear Level Density): - Format: Special format described in documentation; - Origin: Huang Zhongfu et al. CENPL - OMP (Optical model parameter sub-library): - Format: special format described in documentation ; - Origin: CENDL, ENDF/B-VI, JENDL-3. CENPL - MC (I) and (II) (Atomic masses and characteristic constants for nuclear ground states) : - Format: Brief table format; - Nuclides: 4760 nuclides ranging from Z=0 A=1 to Z=122 A=318. - Origin: Experimental data and systematic results evaluated by Wapstra, theoretical results calculated by Moller, ENSDF - BNL and Nuclear Wallet Cards. CENPL contains the following six sub-libraries: 1. Atomic Masses and Characteristic Constants for nuclear ground states (MCC). This data consists of calculated and in most cases also measured mass excesses, atomic masses, total binding energies, spins, parities, and half-lives of nuclear ground states, abundances, etc. for 4800 nuclides. 2. Discrete Level Schemes and branching ratios of gamma decay (DLS). The data on nuclear discrete levels are based on the Evaluated

  11. Electroexcitation of giant multipole resonances in 208Pb

    International Nuclear Information System (INIS)

    Sasao, M.; Torizuka, Y.

    1977-01-01

    Electroexcitation of the nuclear continuum for 208 Pb at excitation energies up to 100 MeV has been measured at momentum transfers in the range from 0.45 to 1.2 fm -1 . Unfolding of the radiation tail was performed using a tail function which takes into account the multiple-photon emission effect. The spectra at these momentum transfers deviate significantly from the prediction of the Fermi-gas model but are consistent with the sum of the multipole strengths of the random-phase approximation; the excess cross section on the low excitation energy side indicates the excitation of multipole resonances. A series of 208 Pb spectra at low momentum transfers was expanded into E1, E2 (E0), E3, and higher multipole components using the q dependence of the Tassie model for isoscalar modes and the Goldhaber-Teller or Steinwedel-Jensen model for isovector modes. The giant dipole resonance thus obtained is consistent with that from photoreactions. Isoscalar and isovector giant quadrupole resonances are seen, respectively, at 11 and 22.5 MeV and an octupole resonance at 16 MeV. A monopole resonance is suggested at 13.5 MeV. The reduced 2 > 2 , B (E1), B (E2), and B (E3) consume most of the corresponding energy weighted sum rule if the q dependences of the Tassie and Goldhaber-Teller models are assumed. The results with these models are consistent with the random-phase approximation

  12. Electric dipole moments reconsidered

    International Nuclear Information System (INIS)

    Rupertsberger, H.

    1989-01-01

    The electric dipole moments of elementary particles, atoms, molecules and their connection to the electric susceptibility are discussed for stationary states. Assuming rotational invariance it is emphasized that for such states only in the case of a parity and time reversal violating interaction the considered particles can obtain a nonvanishing expectation value for the electric dipole moment. 1 fig., 13 refs. (Author)

  13. UNK superconducting dipole development

    International Nuclear Information System (INIS)

    Ageev, A.I.; Andreev, N.I.; Balbekov, V.I.

    1987-01-01

    For choozing the design of superconducting dipoles (SCD) for the IHEP UNK the test results for SCD with warm and cold iron are given. The main parameters of dipoles are presented. The SCD designs are described. At present works on SP magnet simulation for UNK are carried out in two directions. Tests are conducted on a rig with a chain of series dipoles with a warm magnetic screen. The purpose of these tests is to study heat exchange and hydraulics in magnets, energy and helium evacuation in emergency magnet transition into normal conditions, simulation of possible cooling and heating schemes. Another direction involves production of short and full-scale dipole models with cold iron and their testing on rigs. The final choice of the dipole design for commercial production is planned for 1987

  14. New properties of giant resonances in highly excited nuclei

    International Nuclear Information System (INIS)

    Morsch, H.P.

    1991-01-01

    Studies on the giant dipole resonance in very hot nuclei investigated in heavy ion-induced particle-γ coincidence experiments are reviewed. A signature is found in the γ-decay of excited nuceli which shows direct decay of the giant dipole resonance. This provides a new dimension in giant resonance studies and the possibility to study the dependence of giant resonance energy, width and sum rule strength on excitation energy and rotation of the system. Further, the fact that the giant resonance splits in deformed nuclei provides a unique way to get information on the shape of hot nuclei. First results are obtained on the following questions: (i)What is the nuclear shape at high temperature (T≥2 MeV)? (ii)Is there a phase transition in the nuclear shape at T∼1.7 MeV? (iii)Does motional narrowing exist in hot nuclei? (author). 19 refs., 11 figs

  15. Relativistic quasiparticle time blocking approximation: Dipole response of open-shell nuclei

    International Nuclear Information System (INIS)

    Litvinova, E.; Ring, P.; Tselyaev, V.

    2008-01-01

    The self-consistent relativistic quasiparticle random-phase approximation (RQRPA) is extended by the quasiparticle-phonon coupling (QPC) model using the quasiparticle time blocking approximation (QTBA). The method is formulated in terms of the Bethe-Salpeter equation (BSE) in the two-quasiparticle space with an energy-dependent two-quasiparticle residual interaction. This equation is solved either in the basis of Dirac states forming the self-consistent solution of the ground state or in the momentum representation. Pairing correlations are treated within the Bardeen-Cooper-Schrieffer (BCS) model with a monopole-monopole interaction. The same NL3 set of the coupling constants generates the Dirac-Hartree-BCS single-quasiparticle spectrum, the static part of the residual two-quasiparticle interaction and the quasiparticle-phonon coupling amplitudes. A quantitative description of electric dipole excitations in the chain of tin isotopes (Z=50) with the mass numbers A=100,106,114,116,120, and 130 and in the chain of isotones with (N=50) 88 Sr, 90 Zr, 92 Mo is performed within this framework. The RQRPA extended by the coupling to collective vibrations generates spectra with a multitude of 2q x phonon (two quasiparticles plus phonon) states providing a noticeable fragmentation of the giant dipole resonance as well as of the soft dipole mode (pygmy resonance) in the nuclei under investigation. The results obtained for the photo absorption cross sections and for the integrated contributions of the low-lying strength to the calculated dipole spectra agree very well with the available experimental data

  16. Statistical decay of dipole-excited states of Zr isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Gayer, Udo; Zweidinger, Markus; Beck, Tobias; Mertes, Laura; Pai, Haridas; Pietralla, Norbert; Ries, Philipp; Romig, Christopher; Werner, Volker [IKP, TU Darmstadt (Germany); Cooper, Nathan [University of Richmond, Richmond (United States); Isaak, Johann [EMMI, GSI, Darmstadt (Germany); FIAS, Frankfurt (Germany); Loeher, Bastian; Savran, Deniz [GSI, Darmstadt (Germany); Scheck, Marcus [School of Engineering, UWS, Paisley (United Kingdom); SUPA, Glasgow (United Kingdom); Tornow, Werner [Duke University, Durham (United States)

    2016-07-01

    Decay properties of electric dipole excitations below the neutron separation threshold of {sup 92,94,96}Zr have been determined in several (γ,γ') and (vector γ,γ') experiments at the Darmstadt High Intensity Photon Setup and the High-Intensity Gamma-Ray Source in Durham, USA. The model of statistical decay is used to guide an interpretation of this low-lying dipole strength which is frequently discussed to arise from the low-energy tail of the giant dipole resonance and potentially an additional resonance structure often referred to as the pygmy dipole resonance. The availability of three complete data sets in the Zr isotopic chain allowed for a precise test of these extrapolations to low energies using different models for the level density and the photon strength function. In the talk, data and calculations are presented, and the suitability of photon scattering data for this kind of analysis is discussed.

  17. Electron scattering studies of selected electric and magnetic dipole and quadrupole transitions in light and heavy nuclei, the new multipole giant resonances and atomic transitions - recent results from the DALINAC

    International Nuclear Information System (INIS)

    Richter, A.

    1977-01-01

    Recent experimental work from the Darmstadt electron linear accelerator (DALINAC) is briefly summarized. Particular emphasis is given to the following topics: high resolution inelastic electron scattering (ΔE approximately 30 keV FWHM) has been used to study the radiative width and magnetization density of the 2 + , T = 1 state at 16.11 MeV in 12 C, E2 strength distribution in 28 Si below an excitation energy of 13 MeV and the isospin forbidden E1 electroexcitation of the 1 - , T = 0 state at 6.95 MeV in 40 Ca. High resolution inelastic electron scattering was also employed to determine certain M1 transitions in 14 N, 28 Si, 39 K, 58 Ni, 90 Zr and 208 Pb and the M2 strength distribution in the two heaviest nuclei. At medium energy resolution (ΔE approximately 200 keV FWHM) spectra at various angles and bombarding energies have been measured from (4-31) MeV for 208 Pb. They are being analyzed in order to determine E0, E1, E2, E3 and M1 giant resonance strength in the continuum. The Z and E dependence and the scaling behaviour of the atomic inner shell ionization cross section at relativistic electron impact is studied on gaseous and solid targets. (orig./BJ) [de

  18. Changes in earth's dipole.

    Science.gov (United States)

    Olson, Peter; Amit, Hagay

    2006-11-01

    The dipole moment of Earth's magnetic field has decreased by nearly 9% over the past 150 years and by about 30% over the past 2,000 years according to archeomagnetic measurements. Here, we explore the causes and the implications of this rapid change. Maps of the geomagnetic field on the core-mantle boundary derived from ground-based and satellite measurements reveal that most of the present episode of dipole moment decrease originates in the southern hemisphere. Weakening and equatorward advection of normal polarity magnetic field by the core flow, combined with proliferation and growth of regions where the magnetic polarity is reversed, are reducing the dipole moment on the core-mantle boundary. Growth of these reversed flux regions has occurred over the past century or longer and is associated with the expansion of the South Atlantic Anomaly, a low-intensity region in the geomagnetic field that presents a radiation hazard at satellite altitudes. We address the speculation that the present episode of dipole moment decrease is a precursor to the next geomagnetic polarity reversal. The paleomagnetic record contains a broad spectrum of dipole moment fluctuations with polarity reversals typically occurring during dipole moment lows. However, the dipole moment is stronger today than its long time average, indicating that polarity reversal is not likely unless the current episode of moment decrease continues for a thousand years or more.

  19. Lepton dipole moments

    CERN Document Server

    Marciano, William J

    2010-01-01

    This book provides a self-contained description of the measurements of the magnetic dipole moments of the electron and muon, along with a discussion of the measurements of the fine structure constant, and the theory associated with magnetic and electric dipole moments. Also included are the searches for a permanent electric dipole moment of the electron, muon, neutron and atomic nuclei. The related topic of the transition moment for lepton flavor violating processes, such as neutrinoless muon or tauon decays, and the search for such processes are included as well. The papers, written by many o

  20. 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)

  1. Spectral structure of the pygmy dipole resonance.

    Science.gov (United States)

    Tonchev, A P; Hammond, S L; Kelley, J H; Kwan, E; Lenske, H; Rusev, G; Tornow, W; Tsoneva, N

    2010-02-19

    High-sensitivity studies of E1 and M1 transitions observed in the reaction 138Ba(gamma,gamma{'}) at energies below the one-neutron separation energy have been performed using the nearly monoenergetic and 100% linearly polarized photon beams of the HIgammaS facility. The electric dipole character of the so-called "pygmy" dipole resonance was experimentally verified for excitations from 4.0 to 8.6 MeV. The fine structure of the M1 "spin-flip" mode was observed for the first time in N=82 nuclei.

  2. Some dipole shower studies

    Science.gov (United States)

    Cabouat, Baptiste; Sjöstrand, Torbjörn

    2018-03-01

    Parton showers have become a standard component in the description of high-energy collisions. Nowadays most final-state ones are of the dipole character, wherein a pair of partons branches into three, with energy and momentum preserved inside this subsystem. For initial-state showers a dipole picture is also possible and commonly used, but the older global-recoil strategy remains a valid alternative, wherein larger groups of partons share the energy-momentum preservation task. In this article we introduce and implement a dipole picture also for initial-state radiation in Pythia, and compare with the existing global-recoil one, and with data. For the case of Deeply Inelastic Scattering we can directly compare with matrix element expressions and show that the dipole picture gives a very good description over the whole phase space, at least for the first branching.

  3. Particle electric dipole moments

    CERN Document Server

    Pendlebury, J M

    2000-01-01

    Measurements of particle electric dipole moments (EDMs) continue to put powerful constraints on theories of T-symmetry and CP-symmetry violation, which form currently one of the most prominent fields in particle physics. EDM measurements have been concentrated on neutral systems such as the neutron and atoms and molecules. These measurements allow one to deduce, in turn, the electric dipole moments of the fundamental fermions, that is, the lighter leptons and quarks and also those of some heavy nuclei.

  4. A density variational approach to nuclear giant resonances at zero and finite temperature

    International Nuclear Information System (INIS)

    Gleissl, P.; Brack, M.; Quentin, P.; Meyer, J.

    1989-02-01

    We present a density functional approach to the description of nuclear giant resonances (GR), using Skyrme type effective interactions. We exploit hereby the theorems of Thouless and others, relating RPA sum rules to static (constrained) Hartree-Fock expectation values. The latter are calculated both microscopically and, where shell effects are small enough to allow it, semiclassically by a density variational method employing the gradient-expanded density functionals of the extended Thomas-Fermi model. We obtain an excellent overall description of both systematics and detailed isotopic dependence of GR energies, in particular with the Skyrme force SkM. For the breathing modes (isoscalar and isovector giant monopole modes), and to some extent also for the isovector dipole mode, the A-dependence of the experimental peak energies is better described by coupling two different modes (corresponding to two different excitation operators) of the same spin and parity and evaluating the eigenmodes of the coupled system. Our calculations are also extended to highly excited nuclei (without angular momentum) and the temperature dependence of the various GR energies is discussed

  5. Tacoma mode

    International Nuclear Information System (INIS)

    Courant, E.D.; Ruth, R.D.; Wang, J.M.

    1979-01-01

    The name Tacoma refers to the Tacoma Narrows Bridge which collapsed on November 8, 1940 due to massive oscillations caused by high winds. One of the destructive modes was a torsion mode which was excited by transverse wind, a dipole force, and continued until the bridge collapsed. The name is used to refer to a coherent mode of oscillation of a spectrum of oscillators in which the amplitude vs frequency graph contains one node, where the node occurs near the driving frequency and a ω is not symmetric about zero. When this result is applied to vertical instabilities in coasting beams, it implies the existence of a coherent skew quadrupole moment, Q/sub xy/, whenever a coherent dipole oscillation exists

  6. Tacoma mode

    International Nuclear Information System (INIS)

    Courant, E.D.; Ruth, R.D.; Wang, J.M.

    1979-01-01

    The name Tacoma refers to the Tacoma Narrows Bridge which collapsed on November 8, 1940 due to massive oscillations caused by high winds. One of the destructive modes was a torsion mode which was excited by transverse wind, a dipole force, and continued until the bridge collapsed. The name is used to refer to a coherent mode of oscillation of a spectrum of oscillators in which the amplitude vs frequency graph contains one node, where the node occurs near the driving frequency and a(ω) is not symmetric about zero. When this result is applied to vertical instabilities in coasting beams, it implies the existence of a coherent skew quadrupole moment, whenever a coherent dipole oscillation exists

  7. Dynamics of nonstationary dipole vortices

    DEFF Research Database (Denmark)

    Hesthaven, J.S.; Lynov, Jens-Peter; Nycander, J.

    1993-01-01

    The dynamics of tilted dipole vortices in the equivalent barotropic vorticity (or Hasegawa-Mima) equation is studied. A recent theory is compared with numerical simulations and found to describe the short time behavior of dipole vortices well. In the long time limit the dipoles are found to eithe...... disintegrate or relax toward a steady eastward propagating dipole vortex. This relaxation is a consequence of nonviscous enstrophy loss by the dipole vortex....

  8. Dipole-dipole dispersion interactions between neutrons

    OpenAIRE

    Babb, James F.; Higa, Renato; Hussein, Mahir S.

    2016-01-01

    We investigate the long-range interactions between two neutrons utilizing recent data on the neutron static and dynamic electric and magnetic dipole polarizabilities. The resulting long-range potentials are used to make quantitative comparisons between the collisions of a neutron with a neutron and a neutron with a proton. We also assess the importance of the first pion production threshold and first excited state of the nucleon, the $\\Delta$-resonance ($J^{\\pi}$ = + 3/2, I = 3/2). We found b...

  9. Giant Chancroid

    Directory of Open Access Journals (Sweden)

    Bhushan Kumar

    1980-01-01

    Full Text Available A case of giant chancroid following rupture of inguinal bubo and having systemic symptoms is described. Response with sulfa and streptomycin combination was excellent and the lesion healed completely in 3 weeks. Early diagnosis and treatment of chancroid will prevent this debilitating complication.

  10. Giant microelectronics

    International Nuclear Information System (INIS)

    Della Sala, D.; Privato, C.; Di Lazzaro, P.; Fortunato, G.

    1999-01-01

    Giant microelectronics, on which the technology of flat liquid-crystal screens is based, is an example of fruitful interaction among independently-developed technologies, in this case thin film micro devices and laser applications. It typifies the interdisciplinary approach needed to produce innovations in microelectronics [it

  11. Finite temperature effects on monopole and dipole excitations

    International Nuclear Information System (INIS)

    Niu, Y F; Paar, N; Vretenar, D; Meng, J

    2011-01-01

    The relativistic random phase approximation based on effective Lagrangian with density dependent meson-nucleon couplings has been extended to finite temperature and employed in studies of multipole excitations within the temperature range T = 1 - 2 MeV. The model calculations showed that isoscalar giant monopole and isovector giant dipole resonances are only slightly modified with temperature, but additional transition strength appears at low energies because of thermal unblocking of single-particle orbitals close to the Fermi level. The analysis of low-lying states shows that isoscalar monopole response in 132 Sn results from single particle transitions, while the isovector dipole strength for 60 Ni, located around 10 MeV, is composed of several single particle transitions, accumulating a small degree of collectivity.

  12. Dipoles at rest

    International Nuclear Information System (INIS)

    Griffiths, D.J.

    1992-01-01

    In a world populated by magnetic monopoles (as well as ordinary electric charges), there are two kinds of electric dipoles: those due to separated electric charges, and those due to current loops of magnetic charge. Similarly, there are two kinds of magnetic dipoles: those due to separated magnetic monopoles, and those due to electric current loops. This paper derives the potentials and fields of each of the four dipole species, and calculates the force, torque, energy, momentum, and angular momentum of each type, when placed (at rest) in a static external field (which may itself be produced by electric charges and currents, magnetic charges and currents, or all of these). Some implications and applications of the various results are discussed

  13. Automating dipole subtraction

    International Nuclear Information System (INIS)

    Hasegawa, K.; Moch, S.; Uwer, P.

    2008-07-01

    We report on automating the Catani-Seymour dipole subtraction which is a general procedure to treat infrared divergences in real emission processes at next-to-leading order in QCD. The automatization rests on three essential steps: the creation of the dipole terms, the calculation of the color linked squared Born matrix elements, and the evaluation of different helicity amplitudes. The routines have been tested for a number of complex processes, such as the real emission process gg→t anti tggg. (orig.)

  14. Automating dipole subtraction

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, K.; Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Uwer, P. [Karlsruhe Univ. (T.H.) (Germany). Inst. fuer Theoretische Teilchenphysik

    2008-07-15

    We report on automating the Catani-Seymour dipole subtraction which is a general procedure to treat infrared divergences in real emission processes at next-to-leading order in QCD. The automatization rests on three essential steps: the creation of the dipole terms, the calculation of the color linked squared Born matrix elements, and the evaluation of different helicity amplitudes. The routines have been tested for a number of complex processes, such as the real emission process gg{yields}t anti tggg. (orig.)

  15. Automatic dipole subtraction

    International Nuclear Information System (INIS)

    Hasegawa, K.

    2008-01-01

    The Catani-Seymour dipole subtraction is a general procedure to treat infrared divergences in real emission processes at next-to-leading order in QCD. We automatized the procedure in a computer code. The code is useful especially for the processes with many parton legs. In this talk, we first explain the algorithm of the dipole subtraction and the whole structure of our code. After that we show the results for some processes where the infrared divergences of real emission processes are subtracted. (author)

  16. Dipole-dipole van der Waals interaction in alkali halides

    International Nuclear Information System (INIS)

    Thakur, B.N.; Thakur, K.P.

    1978-01-01

    Values of van der Waals dipole-dipole constants and interaction energetics of alkali halides are reported using the recent data. The values obtained are somewhat larger than those of earlier workers. (orig.) [de

  17. On the state space of the dipole ghost

    International Nuclear Information System (INIS)

    Binegar, B.

    1984-01-01

    A particular representation of SO(4, 2) is identified with the state space of the free dipole ghost. This representation is then given an explicit realization as the solution space of a 4th-order wave equation on a spacetime locally isomorphic to Minkowski space. A discrete basis for this solution space is given, as well as an explicit expression for its SO(4, 2) invariant inner product. The connection between the modes of dipole field and those of the massless scalar field is clarified, and a recent conjecture concerning the restriction of the dipole representation to the Poincare subgroup is confirmed. A particular coordinate transformation then reveals the theory of the dipole ghost in Minkowski space. Finally, it is shown that the solution space of the dipole equation is not unitarizable in a Poincare invariant manner. (orig.)

  18. Dipole stabilizer rods for 400 keV deuteron RFQ

    International Nuclear Information System (INIS)

    Sista, V.L.S. Rao; Srivastava, S.C.L.; Pande, Rajni; Roy, Shweta; Singh, P.

    2009-01-01

    In our 400 keV deuteron RFQ for neutron production, the destructive dipolar modes are very close to the required quadrupolar mode. In order to increase the spacing between the quadrupole and dipole modes the dipolar stabilizer rods (DSR's) are used. The design of the DSR's is done using the computer code CST Microwave studio. The variation of the quadrupole and dipolar mode frequencies with the radius and length of the DSR's are studied. (author)

  19. The electric dipole response of neutron rich tin isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Horvat, Andrea; Aumann, Thomas; Rossi, Dominic; Schindler, Fabia [Institut fuer Kernphysik, TU Darmstadt (Germany); Boretzky, Konstanze [GSI Helmholzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Johansen, Jacob [Aarhus University (Denmark); Schrock, Philipp [The University of Tokyo (Japan); Collaboration: R3B-Collaboration

    2016-07-01

    Studies of the dipole response in medium heavy and heavy neutron rich nuclei reveal valuable information about the isospin dependence of the nuclear equation of state. Therefore an experimental campaign investigating both the electric dipole response via Coulomb excitation and neutron removal along the tin isotope chain ({sup 124-134}Sn) has been carried out at the R3B (Reactions with Relativistic Radioactive Beams) setup at GSI (Helmholtzzentrum fuer Schwerionenforschung) for which the analysis is ongoing. The E1 response was induced via relativistic Coulomb scattering by a lead target in inverse kinematics, and calls for a kinematically complete determination of all reaction products in order to reconstruct the excitation energy by means of the invariant mass method. The goal is to obtain the Coulomb excitation cross section up to the adiabatic cut-off energy, covering the giant dipole resonance (GDR) range.

  20. Dipole-dipole dispersion interactions between neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Babb, James F. [Harvard-Smithsonian Center for Astrophysics, ITAMP, Cambridge, MA (United States); Higa, Renato [Universidade de Sao Paulo, Instituto de Fisica, Sao Paulo (Brazil); Hussein, Mahir S. [Universidade de Sao Paulo, Instituto de Fisica, Sao Paulo (Brazil); Universidade de Sao Paulo, Instituto de Estudos Avancados, Sao Paulo (Brazil); Departamento de Fisica, Instituto Tecnologico de Aeronautica, CTA, Sao Jose dos Campos (Brazil)

    2017-06-15

    We investigate the long-range interactions between two neutrons utilizing recent data on the neutron static and dynamic electric and magnetic dipole polarizabilities. The resulting long-range potentials are used to make quantitative comparisons between the collisions of a neutron with a neutron and a neutron with a proton. We also assess the importance of the first pion production threshold and first excited state of the nucleon, the Δ-resonance (J{sup π} = +3/2, I = 3/2). We found both dynamical effects to be quite relevant for distances r between ∝ 50 fm up to ∝ 10{sup 3} fm in the nn system, the neutron-wall system and in the wall-neutron-wall system, reaching the expected asymptotic limit beyond that. Relevance of our findings to the confinement of ultra cold neutrons inside bottles is discussed. (orig.)

  1. Photoelectron spectroscopy and the dipole approximation

    Energy Technology Data Exchange (ETDEWEB)

    Hemmers, O.; Hansen, D.L.; Wang, H. [Univ. of Nevada, Las Vegas, NV (United States)] [and others

    1997-04-01

    Photoelectron spectroscopy is a powerful technique because it directly probes, via the measurement of photoelectron kinetic energies, orbital and band structure in valence and core levels in a wide variety of samples. The technique becomes even more powerful when it is performed in an angle-resolved mode, where photoelectrons are distinguished not only by their kinetic energy, but by their direction of emission as well. Determining the probability of electron ejection as a function of angle probes the different quantum-mechanical channels available to a photoemission process, because it is sensitive to phase differences among the channels. As a result, angle-resolved photoemission has been used successfully for many years to provide stringent tests of the understanding of basic physical processes underlying gas-phase and solid-state interactions with radiation. One mainstay in the application of angle-resolved photoelectron spectroscopy is the well-known electric-dipole approximation for photon interactions. In this simplification, all higher-order terms, such as those due to electric-quadrupole and magnetic-dipole interactions, are neglected. As the photon energy increases, however, effects beyond the dipole approximation become important. To best determine the range of validity of the dipole approximation, photoemission measurements on a simple atomic system, neon, where extra-atomic effects cannot play a role, were performed at BL 8.0. The measurements show that deviations from {open_quotes}dipole{close_quotes} expectations in angle-resolved valence photoemission are observable for photon energies down to at least 0.25 keV, and are quite significant at energies around 1 keV. From these results, it is clear that non-dipole angular-distribution effects may need to be considered in any application of angle-resolved photoelectron spectroscopy that uses x-ray photons of energies as low as a few hundred eV.

  2. INTERNAL ROTATION OF THE RED-GIANT STAR KIC 4448777 BY MEANS OF ASTEROSEISMIC INVERSION

    Energy Technology Data Exchange (ETDEWEB)

    Di Mauro, M. P.; Cardini, D. [INAF, IAPS Istituto di Astrofisica e Planetologia Spaziali, Roma (Italy); Ventura, R.; Paternò, L. [INAF, Astrophysical Observatory of Catania, Catania (Italy); Stello, D. [Sydney Institute for Astronomy, School of Physics, University of Sydney (Australia); Christensen-Dalsgaard, J.; Hekker, S. [Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Dziembowski, W. A. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warsaw (Poland); Beck, P. G.; De Smedt, K.; Tkachenko, A. [Instituut voor Sterrenkunde, Katholieke Universiteit Leuven (Belgium); Bloemen, S. [Department of Astrophysics, IMAPP, Radboud University Nijmegen, P.O. Box 9010, NL-6500 GL, Nijmegen (Netherlands); Davies, G. R.; Garcia, R. A. [Laboratoire AIM, CEA/DSM-CNRS-Univ. Paris Diderot, IRFU/Sap, Centre de Saclay, F-91191 Gif-sur-Yvette Cedex (France); Elsworth, Y. [School of Physics and Astronomy, University of Birmingham (United Kingdom); Mosser, B. [LESIA, PSL Research University, CNRS, Universitè Pierre et Marie Curie, Université Denis Diderot, Observatoire de Paris, Meudon Cedex (France)

    2016-01-20

    We study the dynamics of the stellar interior of the early red-giant star KIC 4448777 by asteroseismic inversion of 14 splittings of the dipole mixed modes obtained from Kepler observations. In order to overcome the complexity of the oscillation pattern typical of red-giant stars, we present a procedure to extract the rotational splittings from the power spectrum. We find not only that the core rotates from a minimum of 8 to a maximum of 17 times faster than the surface, confirming previous inversion results generated for other red giants (Deheuvels et al.), but we also estimate the variation of the angular velocity within the helium core with a spatial resolution of 0.001R and verify the hypothesis of a sharp discontinuity in the inner stellar rotation. The results show that the entire core rotates rigidly and provide evidence for an angular velocity gradient around the base of the hydrogen-burning shell; however, we do not succeed in characterizing the rotational slope, due to the intrinsic limits of the applied techniques. The angular velocity, from the edge of the core, appears to decrease with increasing distance from the center, reaching an average value in the convective envelope of 68 ± 22 nHz. We conclude that a set of data that includes only dipolar modes is sufficient to infer quite accurately the rotation of a red giant not only in the dense core but also, with a lower level of confidence, in part of the radiative region and in the convective envelope.

  3. The Electromagnetic Dipole Radiation Field through the Hamiltonian Approach

    Science.gov (United States)

    Likar, A.; Razpet, N.

    2009-01-01

    The dipole radiation from an oscillating charge is treated using the Hamiltonian approach to electrodynamics where the concept of cavity modes plays a central role. We show that the calculation of the radiation field can be obtained in a closed form within this approach by emphasizing the role of coherence between the cavity modes, which is…

  4. Electrically Small Magnetic Dipole Antennas with Magnetic Core

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Breinbjerg, Olav

    2010-01-01

    This work extends the theory of a spherical magnetic dipole antenna with magnetic core by numerical results for practical antenna configurations that excite higher-order modes besides the main TE10 spherical mode. The multiarm spherical helix (MSH) and the spherical split ring (SSR) antennas...

  5. Dipole-dipole interaction of dust grains in plasmas

    International Nuclear Information System (INIS)

    Tskhakaya, D.D.; Shukla, P.K.

    2005-01-01

    Complete screening of the negative dust grain charge by a cloud of trapped ions in plasmas is investigated. In the external electric field, the compound dust particle - 'dust grain + ion cloud' acquires a dipole moment due to displacement of the centers of positive and negative charges in the opposite directions. By analogy to the Van der Waals potential, the dipole-dipole interaction of the compound dust particles can have an attractive behavior. It is shown that the dipole-dipole attractive force can exceed the shadowing force that is connected with the reciprocal interception of ions by the neighboring dust grains

  6. Electrostatic stability of electron-positron plasmas in dipole geometry

    OpenAIRE

    Mishchenko, Alexey; Plunk, Gabriel; Helander, Per

    2017-01-01

    The electrostatic stability of electron-positron plasmas is investigated in the point-dipole and Z-pinch limits of dipole geometry. The kinetic dispersion relation for sub-bounce-frequency instabilities is derived and solved. For the zero-Debye-length case, the stability diagram is found to exhibit singular behavior. However, when the Debye length is non-zero, a fluid mode appears, which resolves the observed singularity, and also demonstrates that both the temperature and density gradients c...

  7. Giant resonances: reaction theory approach

    International Nuclear Information System (INIS)

    Toledo Piza, A.F.R. de; Foglia, G.A.

    1989-09-01

    The study of giant resonances through the use of reaction theory approach is presented and discussed. Measurements of cross-sections to the many available decay channels following excitation of giant multipole resonances (GMR) led one to view these phenomena as complicated dynamical syndromes so that theoretical requirements for their study must be extended beyond the traditional bounds of nuclear structure models. The spectra of decay products following GMR excitation in heavy nuclei are well described by statistical model (Hauser-Feshback, HF) predictions indicated that spreading of the collective modes plays a major role in shaping exclusive cross-sections. (A.C.A.S.) [pt

  8. Isotopic dependence of the giant quadrupole resonance in the stable even-mass molybdenum nuclei

    International Nuclear Information System (INIS)

    Moalem, A.; Gaillard, Y.; Bemolle, A.M.; Buenerd, M.; Chauvin, J.; Duhamel, G.; Lebrun, D.; Martin, P.; Perrin, G.; de Saintignon, P.

    1979-01-01

    Inelastic scattering of 110 MeV 3 He particles is used to probe the quadrupole strength in the even Mo isotopes. The peak position of the giant quadrupole resonance is found to decrease more rapidly than predicted by the A/sup -1/3/ law, a behavior very similar to that exhibited by the photonuclear giant dipole resonance. The width and strength of the giant quadrupole resonance are practically constant in 92 Mo through 100 Mo

  9. Dissecting an LHC dipole

    CERN Multimedia

    2004-01-01

    The cold mass of a 15-metre main dipole magnet has some fifteen different components. All the main components are manufactured under CERN's direct responsibility. Four of them transit through CERN before being shipped to the dipole assembly contractors, namely the cable, which constitutes the magnet's superconducting core (see Bulletin 14/2004), the beam screens, the heat exchanger tubes and the cold bore beam tubes. The two latter components transit via Building 927 where they undergo part of the production process. The 58-mm diameter heat exchanger tubes will remove heat from the magnets using superfluid helium. The 53-mm diameter cold bore tubes will be placed under vacuum to allow the twin beams to circulate around the LHC.

  10. Dipole polarizability and neutron skin in {sup 68}Ni

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Dominic [GSI Darmstadt (Germany); Univ. Mainz (Germany); NSCL, MSU (United States); Aumann, Thomas [TU Darmstadt (Germany); Boretzky, Konstanze [GSI Darmstadt (Germany); Collaboration: R3B-Collaboration

    2014-07-01

    The symmetry energy term E{sub sym} of the nuclear equation-of-state describes fundamental phenomena both in nuclear physics and in astrophysics. The electric dipole (E1) response of nuclei as a function of the isospin asymmetry is driven by E{sub sym} and in particular by its density dependence. Studies of the Pygmy Dipole Resonance (PDR) in exotic nuclei have been used to constrain E{sub sym} or the neutron skin thickness ΔR{sub n,p}. The electric dipole polarizability α{sub D}, being very sensitive to the low-lying E1 strength, is correlated to ΔR{sub n,p} in a robust and only moderately less model-dependent manner [PRC 81, 051303 (2010)]. Recently, for the stable nucleus, 208Pb the neutron skin thickness was extracted from the measured αD. Here, a first experimental determination of α{sub D} in an unstable nucleus and the derivation of its ΔR{sub n,p} will be reported. Coulomb excitation in inverse kinematics at the R3B-LAND setup at GSI allows for the investigation of the dipole strength distribution in the neutron-rich {sup 68}Ni covering the pygmy (PDR) and giant dipole resonance (GDR). The E1 strength distribution in the neutron-rich {sup 68}Ni covering the pygmy (PDR) and giant dipole resonance (GDR) s investigated using the R3B-LAND setup at GSI. From the E1 strength distribution in {sup 68}Ni measured using the R3B-LAND setup at GSI, the resonance parameters for the observed PDR at 9.55(17) MeV and the giant dipole resonance at 17.1(2) MeV are determined. In combination with results from Wieland et al. [PRL 102, 092502 (2009)] an unexpectedly large direct photon-decay branching ratio of 7(2) is observed for the PDR. The measured α{sub D} of 3.40(23) fm{sup 3} is compared to relativistic RPA calculations yielding ΔR{sub n,p} of 0.17(2) fm for {sup 68}Ni.

  11. Experiments with dipole antennas

    International Nuclear Information System (INIS)

    Kraftmakher, Yaakov

    2009-01-01

    Employment of a data-acquisition system for data collection and calculations makes experiments with antennas more convenient and less time consuming. The determined directional patterns of the dipole antennas of different lengths are in reasonable agreement with theory. The enhancement of the signal by using a reflector is demonstrated, and a variant of the Yagi-Uda antenna is explored. The experiments are suitable as laboratory works and classroom demonstrations, and are attractive for student projects.

  12. ALICE dipole and decoration

    CERN Multimedia

    Maximilien Brice

    2004-01-01

    The ALICE cavern receives a painting made specially to mark the 50th anniversary of CERN that is mounted on the L3 solenoid magnet, reused from the LEP experiment that ran from 1989 to 2000. The dipole, which is cooled by demineralised water, will bend the path of muons that leave the huge rectangular solenoid. These muons are heavy electrons that interact less with matter allowing them to be studied at large distances from the interaction point.

  13. Visualizing dipole radiation

    International Nuclear Information System (INIS)

    Girwidz, Raimund V

    2016-01-01

    The Hertzian dipole is fundamental to the understanding of dipole radiation. It provides basic insights into the genesis of electromagnetic waves and lays the groundwork for an understanding of half-wave antennae and other types. Equations for the electric and magnetic fields of such a dipole can be derived mathematically. However these are very abstract descriptions. Interpreting these equations and understanding travelling electromagnetic waves are highly limited in that sense. Visualizations can be a valuable supplement that vividly present properties of electromagnetic fields and their propagation. The computer simulation presented below provides additional instructive illustrations for university lectures on electrodynamics, broadening the experience well beyond what is possible with abstract equations. This paper refers to a multimedia program for PCs, tablets and smartphones, and introduces and discusses several animated illustrations. Special features of multiple representations and combined illustrations will be used to provide insight into spatial and temporal characteristics of field distributions—which also draw attention to the flow of energy. These visualizations offer additional information, including the relationships between different representations that promote deeper understanding. Finally, some aspects are also illustrated that often remain unclear in lectures. (paper)

  14. Dipole defects in beryl

    International Nuclear Information System (INIS)

    Holanda, B A; Cordeiro, R C; Blak, A R

    2010-01-01

    Dipole defects in gamma irradiated and thermally treated beryl (Be 3 Al 2 Si 6 O 18 ) samples have been studied using the Thermally Stimulated Depolarization Currents (TSDC) technique. TSDC experiments were performed in pink (morganite), green (emerald), blue (aquamarine) and colourless (goshenite) natural beryl. TSDC spectra present dipole peaks at 190K, 220K, 280K and 310K that change after gamma irradiation and thermal treatments. In morganite samples, for thermal treatments between 700K and 1100K, the 280K peak increase in intensity and the band at 220K disappears. An increase of the 280K peak and a decrease of the 190K peak were observed in the TSDC spectra of morganite after a gamma irradiation of 25kGy performed after the thermal treatments. In the case of emerald samples, thermal treatments enhanced the 280K peak and gamma irradiation partially destroyed this band. The goshenite TSDC spectra present only one band at 280K that is not affected either by thermal treatments or by gamma irradiation. All the observed peaks are of dipolar origin because the intensity of the bands is linearly dependent on the polarization field, behaviour of dipole defects. The systematic study, by means of TSDC measurements, of ionizing irradiation effects and thermal treatments in these crystals makes possible a better understanding of the role played by the impurities in beryl crystals.

  15. ON THE POSSIBLE EXISTENCE OF SHORT-PERIOD g-MODE INSTABILITIES POWERED BY NUCLEAR-BURNING SHELLS IN POST-ASYMPTOTIC GIANT BRANCH H-DEFICIENT (PG1159-TYPE) STARS

    International Nuclear Information System (INIS)

    Corsico, A. H.; Althaus, L. G.; Miller Bertolami, M. M.; Gonzalez Perez, J. M.; Kepler, S. O.

    2009-01-01

    We present a pulsational stability analysis of hot post-asymptotic giant branch (AGB) H-deficient pre-white dwarf stars with active He-burning shells. The stellar models employed are state-of-the-art equilibrium structures representative of PG1159 stars derived from the complete evolution of the progenitor stars, through the thermally pulsing AGB phase and born-again episode. On the basis of fully nonadiabatic pulsation computations, we confirmed theoretical evidence for the existence of a separate PG1159 instability strip in the log T eff -log g diagram characterized by short-period g-modes excited by the ε-mechanism. This instability strip partially overlaps the already known GW Vir instability strip of intermediate/long-period g-modes destabilized by the classical κ-mechanism acting on the partial ionization of C and/or O in the envelope of PG1159 stars. We found that PG1159 stars characterized by thick He-rich envelopes and located inside this overlapping region could exhibit both short and intermediate/long periods simultaneously. As a natural application of our results, we study the particular case of VV 47, a pulsating planetary nebula nucleus (PG1159 type) that is particularly interesting because it has been reported to exhibit a rich and complex pulsation spectrum including a series of unusually short pulsation periods. We found that the long periods exhibited by VV 47 can be readily explained by the classical κ-mechanism, while the observed short-period branch below ∼300 s could correspond to modes triggered by the He-burning shell through the ε-mechanism, although more observational work is needed to confirm the reality of these short-period modes. Were the existence of short-period g-modes in this star convincingly confirmed by future observations, VV 47 could be the first known pulsating star in which both the κ-mechanism and the ε-mechanism of mode driving are simultaneously operating.

  16. The Giant Dipole Resonance in hot nuclei. Experimental aspects

    International Nuclear Information System (INIS)

    Alamanos, N.; Auger, F.

    1994-12-01

    Some of the most recent experimental results on the GDR in hot nuclei are presented. All data on the γ-decay of the GDR show a saturation of the apparent width and a saturation of the yield. However, it is not clear until now, if these effects are related to a GDR width which either saturates or increases continuously with the excitation energy. Very new data associated to selected exit channels could help to clarify the situation. (author). 14 refs., 7 figs

  17. Evolution of giant dipole resonance width at low temperatures ...

    Indian Academy of Sciences (India)

    techniques. Several experiments have been performed by bombarding 7–12 MeV/nucleon alpha beam on various targets (63Cu, 115In and 197Au) and new datasets ... appears to be constant at its ground state value until a critical temperature is reached and subse- ..... it was 38.6 MeV for 63Cu at 35 MeV incident energy.

  18. Dipole polarizability of neutron rich nuclei and the symmetry energy

    Energy Technology Data Exchange (ETDEWEB)

    Horvat, Andrea; Johansen, Jacob; Miki, Kenjiro; Schindler, Fabia; Schrock, Philipp [IKP, TU Darmstadt (Germany); Aumann, Thomas [IKP, TU Darmstadt (Germany); GSI, Darmstadt (Germany); Boretzky, Konstanze [GSI, Darmstadt (Germany); Collaboration: R3B-Collaboration

    2015-07-01

    As a part of a systematic investigation of the dipole response of stable up to very neutron rich tin isotopes, nuclear and electromagnetic excitation of {sup 124}Sn-{sup 134}Sn has been investigated at relativistic energies in inverse kinematics induced by carbon and lead targets at the LAND-R3B setup at GSI in Darmstadt. The electric dipole response and the nuclear reaction cross section, total and charge-changing, are obtained from the kinematically complete determination of momenta of all particles on an event by event basis. The dipole polarizability is extracted from the Coulomb excitation interaction channel, in order to make use of relevant correlations of this observable with nuclear matter properties such as the symmetry energy at saturation density (J) and it's slope (L). The systematics of the low-lying ''pygmy'' dipole strength, the giant dipole resonance (GDR) and the neutron skin thickness are determined with respect to increasing isospin asymmetry. This talk also discusses the correlations and sensitivities of these variables and observables obtained within the framework of nuclear energy density functional theory.

  19. A Boltzmann equation approach to the damping of giant resonances in nuclei

    International Nuclear Information System (INIS)

    Schuck, P.; Winter, J.

    1983-01-01

    The Vlasov equation plus collision term (Boltzmann equation) represents an appropriate frame for the treatment of giant resonances (zero sound modes) in nuclei. With no adjustable parameters we obtain correct positions and widths for the giant quadrupole resonances. (author)

  20. Virtual excitation of the GDR mode in the subbarrier /sup 23/Na(p,. gamma. )/sup 24/Mg reaction

    Energy Technology Data Exchange (ETDEWEB)

    Kicinska-Habior, M; Dabrowska, M; Decowski, P; Matulewicz, T; Sikora, B; Toke, J; Cseh, J; Somorjai, E

    1984-10-01

    Differential cross sections for nonresonant radiative capture of low energy protons (Esub(p)=1,348 keV and 1,370 keV) by /sup 23/Na nuclei exhibit features pointing to the virtual excitation of the giant dipole resonance (GDR) mode. Theoretical analysis carried out within the framework of the direct - semidirect capture model reveals an enhanced coupling of the GDR with the incident proton f-wave consistent with the microscopic structure of the GDR in the s-d shell nuclei.

  1. Splitting of the Pygmy Dipole Resonance

    International Nuclear Information System (INIS)

    Endres, J.; Zilges, A.; Butler, P.; Herzberg, R.-D.; Scheck, M.; Harakeh, M. N.; Harissopulos, S.; Lagoyannis, A.; Kruecken, R.; Ring, P.; Litvinova, E.; Pietralla, N.; Ponomarev, V. Yu.; Sonnabend, K.; Popescu, L.; Savran, D.; Stoica, V. I.; Woertche, H. J.

    2011-01-01

    In recent years investigations have been made to study the electric Pygmy Dipole Resonance (PDR) systematically, mainly in semi-magic nuclei. For this purpose the well understood high resolution (γ,γ') photon scattering method is used. In complementary (α,α'γ) coincidence experiments at E α = 136 MeV a similar γ-energy resolution and a high selectivity to E1 transitions can be obtained at the Big-Bite Spectrometer (BBS) at KVI, Groningen. In comparison to the (γ,γ') method a structural splitting of the PDR is observed in the N = 82 nuclei 138 Ba and 140 Ce and in the Z = 50 nucleus 124 Sn. The low energy part is excited in (γ,γ') as well as in (α,α'γ) while the high energy part is observed in (γ,γ') only. The experimental results together with theoretical QPM and RQTBA calculations on 124 Sn which are able to reproduce the splitting of the PDR qualitatively are presented. The low-lying group of J π = 1 - states seem to represent the more isoscalar neutron-skin oscillation of the PDR while the energetically higher-lying states seemingly belong to the transitional region between the PDR and the isovector Giant Dipole Resonance (IVGDR).

  2. Prompt High Energy Dipole γ Emission

    International Nuclear Information System (INIS)

    Corsi, A.; Giaz, A; Bracco, A.

    2011-01-01

    The study of the collective properties of a nuclear system is a powerful tool to understand the structure which lies inside the nucleus. A successful technique which has been used in this field is the measurement of the γ-decay of the highly collective Giant Dipole Resonance (GDR). In fact, GDR can be used as a probe for the internal structure of hot nuclei and, in addition, constitutes a clock for the thermalization process. Using the fusion-evaporation reaction, it has been recently possible to study (i) the yield of the high-energy γ-ray emission of the Dynamical Dipole which takes place during the fusion process and (ii) the degree of isospin mixing at high temperature in the decay of 80 Zr. In the first case it is important to stress the fact that the predictions of the theoretical models might differ depending on the type of nuclear equation of state (EOS) and on the N-N in-medium cross-section used in the calculations while, in the second physics case, the data are relative to the heaviest N = Z nucleus which has been possible to populate in the I = 0 channel using fusion-evaporation reaction. Both experiments were performed at the Laboratori Nazionali di Legnaro using the HECTOR-GARFIELD array. The high-energy γ-rays were measured in coincidence with light charged particles and fusion-evaporation residues. (author)

  3. AutoDipole - Automated generation of dipole subtraction terms

    International Nuclear Information System (INIS)

    Hasegawa, K.; Uwer, P.

    2009-11-01

    We present an automated generation of the subtraction terms for next-to-leading order QCD calculations in the Catani-Seymour dipole formalism. For a given scattering process with n external particles our Mathematica package generates all dipole terms, allowing for bothmassless and massive dipoles. The numerical evaluation of the subtraction terms proceeds with MadGraph, which provides Fortran code for the necessary scattering amplitudes. Checks of the numerical stability are discussed. (orig.)

  4. AutoDipole - Automated generation of dipole subtraction terms

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, K.; Uwer, P. [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2009-11-15

    We present an automated generation of the subtraction terms for next-to-leading order QCD calculations in the Catani-Seymour dipole formalism. For a given scattering process with n external particles our Mathematica package generates all dipole terms, allowing for bothmassless and massive dipoles. The numerical evaluation of the subtraction terms proceeds with MadGraph, which provides Fortran code for the necessary scattering amplitudes. Checks of the numerical stability are discussed. (orig.)

  5. Collective dipole motion in highly excited (272)Hs (Z=108) nuclei

    NARCIS (Netherlands)

    Tveter, TS; Gaardhoje, JJ; Maj, A; Ramsay, T; Atac, A; Bacelar, J; Bracco, A; Buda, A; Camera, F; Herskind, B; Korten, W; Krolas, W; Menthe, A; Million, B; Nifenecker, H; Pignanelli, M; Pinston, JA; vanderPloeg, H; Schussler, F; Sletten, G

    1996-01-01

    The heavy nucleus (272)(108)Hs (Z = 108) and its evaporation daughters were produced using the reaction Th-232(Ar-40, gamma xn) with beam energies 10.5 and 15.0 MeV/A. The giant dipole resonance gamma radiation from the hot composite system prior to fission has been isolated using a differential

  6. Neutron Electric Dipole Moment

    International Nuclear Information System (INIS)

    Mischke, R.E.

    2003-01-01

    The status of experiments to measure the electric dipole moment of the neutron is presented and the planned experiment at Los Alamos is described. The goal of this experiment is an improvement in sensitivity of a factor of 50 to 100 over the current limit. It has the potential to reveal new sources of T and CP violation and to challenge calculations that propose extensions to the Standard Model. The experiment employs several advances in technique to reach its goals and the feasibility of meeting these technical challenges is currently under study

  7. Neutron Electric Dipole Moment from Gauge-String Duality.

    Science.gov (United States)

    Bartolini, Lorenzo; Bigazzi, Francesco; Bolognesi, Stefano; Cotrone, Aldo L; Manenti, Andrea

    2017-03-03

    We compute the electric dipole moment of nucleons in the large N_{c} QCD model by Witten, Sakai, and Sugimoto with N_{f}=2 degenerate massive flavors. Baryons in the model are instantonic solitons of an effective five-dimensional action describing the whole tower of mesonic fields. We find that the dipole electromagnetic form factor of the nucleons, induced by a finite topological θ angle, exhibits complete vector meson dominance. We are able to evaluate the contribution of each vector meson to the final result-a small number of modes are relevant to obtain an accurate estimate. Extrapolating the model parameters to real QCD data, the neutron electric dipole moment is evaluated to be d_{n}=1.8×10^{-16}θ e cm. The electric dipole moment of the proton is exactly the opposite.

  8. Electromagnetic moments and electric dipole transitions in carbon isotopes

    International Nuclear Information System (INIS)

    Suzuki, Toshio; Sagawa, Hiroyuki; Hagino, Kouichi

    2003-01-01

    We carry out shell model calculations to study electromagnetic moments and electric dipole transitions of C isotopes. We point out the configuration dependence of the quadrupole and magnetic moments of the odd C isotopes, which will be useful to find out the deformations and the spin parities of the ground states of these nuclei. We also study the electric dipole states of C isotopes, focusing on the interplay between low energy pigmy strength and giant dipole resonances. As far as the energies of the resonances are concerned, reasonable agreement is obtained with available experimental data for the photoreaction cross sections in 12 C, 13 C, and 14 C, both in the low energy region below (ℎ/2π)ω=14 MeV and in the high energy giant resonance region (14 MeV 15 C is found to exhaust about 12-16 % of the classical Thomas-Reiche-Kuhn sum rule value and 50-80 % of the cluster sum rule value

  9. Magnetic dipole moment of a moving electric dipole

    OpenAIRE

    Hnizdo, V.

    2012-01-01

    The current density of a moving electric dipole is expressed as the sum of polarization and magnetization currents. The magnetic field due to the latter current is that of a magnetic dipole moment that is consistent with the relativistic transformations of the polarization and magnetization of macroscopic electrodynamics.

  10. Collisional transfer of coherence by electric dipole-dipole interaction

    OpenAIRE

    Gough , W.

    1983-01-01

    An expression is derived for the contribution from dipole-dipole interaction to the intensity of sensitized fluorescence, from the results of a theory by Chiu. Tensor operator methods are used. The degree of polarization is deduced for certain particular cases.

  11. Magnetic field of a dipole and the dipole-dipole interaction

    International Nuclear Information System (INIS)

    Kraftmakher, Yaakov

    2007-01-01

    With a data-acquisition system and sensors commercially available, it is easy to determine magnetic fields produced by permanent magnets and to study the dipole-dipole interaction for different separations and angular positions of the magnets. For sufficiently large distances, the results confirm the 1/R 3 law for the magnetic field and the 1/R 4 law for the interaction force between two dipoles, as well as their angular dependences

  12. Electric dipole strength and dipole polarizability in 48Ca within a fully self-consistent second random–phase approximation

    Directory of Open Access Journals (Sweden)

    D. Gambacurta

    2018-02-01

    Full Text Available The second random–phase–approximation model corrected by a subtraction procedure designed to cure double counting, instabilities, and ultraviolet divergences, is employed for the first time to analyze the dipole strength and polarizability in 48Ca. All the terms of the residual interaction are included, leading to a fully self-consistent scheme. Results are illustrated with two Skyrme parametrizations, SGII and SLy4. Those obtained with the SGII interaction are particularly satisfactory. In this case, the low-lying strength below the neutron threshold is well reproduced and the giant dipole resonance is described in a very satisfactory way especially in its spreading and fragmentation. Spreading and fragmentation are produced in a natural way within such a theoretical model by the coupling of 1 particle-1 hole and 2 particle-2 hole configurations. Owing to this feature, we may provide for the electric polarizability as a function of the excitation energy a curve with a similar slope around the centroid energy of the giant resonance compared to the corresponding experimental results. This represents a considerable improvement with respect to previous theoretical predictions obtained with the random–phase approximation or with several ab-initio models. In such cases, the spreading width of the excitation cannot be reproduced and the polarizability as a function of the excitation energy displays a stiff increase around the predicted centroid energy of the giant resonance.

  13. Electric dipole strength and dipole polarizability in 48Ca within a fully self-consistent second random-phase approximation

    Science.gov (United States)

    Gambacurta, D.; Grasso, M.; Vasseur, O.

    2018-02-01

    The second random-phase-approximation model corrected by a subtraction procedure designed to cure double counting, instabilities, and ultraviolet divergences, is employed for the first time to analyze the dipole strength and polarizability in 48Ca. All the terms of the residual interaction are included, leading to a fully self-consistent scheme. Results are illustrated with two Skyrme parametrizations, SGII and SLy4. Those obtained with the SGII interaction are particularly satisfactory. In this case, the low-lying strength below the neutron threshold is well reproduced and the giant dipole resonance is described in a very satisfactory way especially in its spreading and fragmentation. Spreading and fragmentation are produced in a natural way within such a theoretical model by the coupling of 1 particle-1 hole and 2 particle-2 hole configurations. Owing to this feature, we may provide for the electric polarizability as a function of the excitation energy a curve with a similar slope around the centroid energy of the giant resonance compared to the corresponding experimental results. This represents a considerable improvement with respect to previous theoretical predictions obtained with the random-phase approximation or with several ab-initio models. In such cases, the spreading width of the excitation cannot be reproduced and the polarizability as a function of the excitation energy displays a stiff increase around the predicted centroid energy of the giant resonance.

  14. Complete dipole response in 208Pb from high-resolution polarized proton scattering at 0 deg

    International Nuclear Information System (INIS)

    Neumann-Cosel, P. von; Kalmykov, Y.; Poltoratska, I.; Ponomarev, V. Yu.; Richter, A.; Wambach, J.; Adachi, T.; Fujita, Y.; Matsubara, H.; Sakemi, Y.; Shimizu, Y.; Tameshige, Y.; Yosoi, M.; Bertulani, C. A.; Carter, J.; Fujita, H.; Dozono, M.; Fujita, K.; Hashimoto, H.; Hatanaka, K.

    2009-01-01

    The structure of electric and magnetic dipole modes in 208 Pb is investigated in a high-resolution measurement of the (p-vector,p-vector') reaction under 0 deg. First results on the E1 strength in the region of the pygmy dipole resonance are reported.

  15. E-plane Beam Width Reconfigurable Dipole Antenna with Tunable Parasitic Strip

    DEFF Research Database (Denmark)

    Zhang, Jin; Zhang, Shuai; Pedersen, Gert F.

    2018-01-01

    A 3-dB E-plane beam width (EPBW) reconfig- urable dipole antenna is proposed in this paper. By introducing a tunable C-shape strip, the EPBW of the dipole antenna can switch in three different modes: narrow, middle and wide. Three pairs of PIN diodes are used for controlling. The beam width tuning...

  16. Complete Electric Dipole Response and the Neutron Skin in 208Pb

    NARCIS (Netherlands)

    Tamii, A.; Poltoratska, I.; Neumann-Cosel, P. von; Fujita, Y.

    2011-01-01

    A benchmark experiment on 208Pb shows that polarized proton inelastic scattering at very forward angles including 0◦ is a powerful tool for high-resolution studies of electric dipole (E1) and spin magnetic dipole (M1) modes in nuclei over a broad excitation energy range to test up-to-date nuclear

  17. Backfire antennas with dipole elements

    DEFF Research Database (Denmark)

    Nielsen, Erik Dragø; Pontoppidan, Knud

    1970-01-01

    A method is set up for a theoretical investigation of arbitrary backfire antennas based upon dipole structures. The mutual impedance between the dipole elements of the antenna is taken into account, and the field radiated due to a surface wave reflector of finite extent is determined by calculating...

  18. Dipole plasma in molecular crystals

    International Nuclear Information System (INIS)

    Kotel'nikov, Yu.E.; Kochelaev, B.I.

    1976-01-01

    Collective oscillations in a system of electric dipoles of molecular crystals are investigated. It has been proved in the exciton approximation that in an elementary cell of a molecular crystal with one molecule there may exist energy fluctuations of the ''dipole'' plasma, analogous to plasma oscillations in the charged Fermi liquid

  19. Neutron Electric Dipole Moment Experiments

    OpenAIRE

    Peng, Jen-Chieh

    2008-01-01

    The neutron electric dipole moment (EDM) provides unique information on CP violation and physics beyond the Standard Model. We first review the history of experimental searches for neutron electric dipole moment. The status of future neutron EDM experiments, including experiments using ultra-cold neutrons produced in superfluid helium, will then be presented.

  20. Mapping the HISS Dipole

    International Nuclear Information System (INIS)

    McParland, C.; Bieser, F.

    1984-01-01

    The principal component of the Bevalac HISS facility is a large super-conducting 3 Tesla dipole. The facility's need for a large magnetic volume spectrometer resulted in a large gap geometry - a 2 meter pole tip diameter and a 1 meter pole gap. Obviously, the field required detailed mapping for effective use as a spectrometer. The mapping device was designed with several major features in mind. The device would measure field values on a grid which described a closed rectangular solid. The grid would be a regular with the exact measurement intervals adjustable by software. The device would function unattended over the long period of time required to complete a field map. During this time, the progress of the map could be monitored by anyone with access to the HISS VAX computer. Details of the mechanical, electrical, and control design follow

  1. Transforming giants.

    Science.gov (United States)

    Kanter, Rosabeth Moss

    2008-01-01

    Large corporations have long been seen as lumbering, inflexible, bureaucratic--and clueless about global developments. But recently some multinationals seem to be transforming themselves: They're engaging employees, moving quickly, and introducing innovations that show true connection with the world. Harvard Business School's Kanter ventured with a research team inside a dozen global giants--including IBM, Procter & Gamble, Omron, CEMEX, Cisco, and Banco Real--to discover what has been driving the change. After conducting more than 350 interviews on five continents, she and her colleagues came away with a strong sense that we are witnessing the dawn of a new model of corporate power: The coordination of actions and decisions on the front lines now appears to stem from widely shared values and a sturdy platform of common processes and technology, not from top-down decrees. In particular, the values that engage the passions of far-flung workforces stress openness, inclusion, and making the world a better place. Through this shift in what might be called their guidance systems, the companies have become as creative and nimble as much smaller ones, even while taking on social and environmental challenges of a scale that only large enterprises could attempt. IBM, for instance, has created a nonprofit partnership, World Community Grid, through which any organization or individual can donate unused computing power to research projects and see what is being done with the donation in real time. IBM has gained an inspiring showcase for its new technology, helped business partners connect with the company in a positive way, and offered individuals all over the globe the chance to contribute to something big.

  2. Giant Cell Arteritis

    Science.gov (United States)

    Giant cell arteritis is a disorder that causes inflammation of your arteries, usually in the scalp, neck, and arms. ... arteries, which keeps blood from flowing well. Giant cell arteritis often occurs with another disorder called polymyalgia ...

  3. Asteroseismic Diagram for Subgiants and Red Giants

    Energy Technology Data Exchange (ETDEWEB)

    Gai, Ning; Tang, Yanke [College of Physics and Electronic information, Dezhou University, Dezhou 253023 (China); Yu, Peng [College of Physics and Electronic Engineering, Chongqing Normal University, Chongqing 401331 (China); Dou, Xianghua, E-mail: ning_gai@163.com, E-mail: tyk450@163.com [Shandong Provincial Key Laboratory of Biophysics, Dezhou University, Dezhou 253023 (China)

    2017-02-10

    Asteroseismology is a powerful tool for constraining stellar parameters. NASA’s Kepler mission is providing individual eigenfrequencies for a huge number of stars, including thousands of red giants. Besides the frequencies of acoustic modes, an important breakthrough of the Kepler mission is the detection of nonradial gravity-dominated mixed-mode oscillations in red giants. Unlike pure acoustic modes, mixed modes probe deeply into the interior of stars, allowing the stellar core properties and evolution of stars to be derived. In this work, using the gravity-mode period spacing and the large frequency separation, we construct the ΔΠ{sub 1}–Δ ν asteroseismic diagram from models of subgiants and red giants with various masses and metallicities. The relationship ΔΠ{sub 1}–Δ ν is able to constrain the ages and masses of the subgiants. Meanwhile, for red giants with masses above 1.5 M {sub ⊙}, the ΔΠ{sub 1}–Δ ν asteroseismic diagram can also work well to constrain the stellar age and mass. Additionally, we calculate the relative “isochrones” τ , which indicate similar evolution states especially for similar mass stars, on the ΔΠ{sub 1}–Δ ν diagram.

  4. Electroexcitation of giant resonances in 181Ta

    International Nuclear Information System (INIS)

    Hicks, R.S.; Auer, I.P.; Bergstrom, J.C.; Caplan, H.S.

    1977-01-01

    The giant resonance region of 181 Ta has been investigated by means of inelastic electron scattering with primary electron energies of 79.1 to 118.3 MeV. A peak-fitting procedure was employed to separate the measured spectrum into nine different resonance components. Multipolarity and strength assignments were deduced using DWBA analysis with the Goldhaber-Teller and Steinwedel-Jensen models. In addition to the well-known giant dipole structure, other resonances were identified at 23.2+-0.3 MeV (E2), 9.5+-0.2 and 11.5+-0.2 MeV (E2 or E0), 19.5+-0.8 MeV (E3), 3.70+-0.14 MeV (E3 or E4), and 5.40+-0.15 MeV (E4 or E5). The model dependence of the analysis is discussed. (Auth.)

  5. Study of giant resonances in heavy nuclei

    International Nuclear Information System (INIS)

    Cataldi, M.I.C.

    1986-01-01

    The electrodisintegration cross section for 181 Ta, 208 Pb and 209 Bi was measured by counting the emitted neutrons, with incident electrons in the energy range 8-22 MeV. The data was analysed using the virtual photon method, in order to obtain a multipole decomposition and the intensities of Magnetic Dipole and Electric Quadrupole, isoscalar and isovector, in the Giant Resonance. The results obtained for the isovector Giant Quadrupole Resonance are compared with the measured photodisintegration cross section, using data from Saclay and Livermore. This comparision indicates that the photodisintegration data can be well explained assuming an isovector E2 Resonance located between 120 and 130 A -1/3 MeV, with an intensity of one isovector E2 sum. (author) [pt

  6. Isotopic dependence of giant multipole resonances

    International Nuclear Information System (INIS)

    Bar Touv, J.; Moalem, A.; Shlomo, S.

    1980-01-01

    A procedure is presented which allows the application of linear response theory and the random phase approximation to an open shell. The procedure is applied to Ca isotopes. The general features of giant multipole resonances are found to vary smoothly with the mass. The resonances exhibit more structure in the open lfsub(7/2) shell nuclei. While the energy-weighted dipole sum is practically constant in all isotopes, the isoscalar quadrupole and octupole energy weighted sums increase continuously by approx. 30% from 40 Ca to 48 Ca. (orig.)

  7. Pressure profiles of plasmas confined in the field of a magnetic dipole

    International Nuclear Information System (INIS)

    Davis, Matthew S; Mauel, M E; Garnier, Darren T; Kesner, Jay

    2014-01-01

    Equilibrium pressure profiles of plasmas confined in the field of a dipole magnet are reconstructed using magnetic and x-ray measurements on the levitated dipole experiment (LDX). LDX operates in two distinct modes: with the dipole mechanically supported and with the dipole magnetically levitated. When the dipole is mechanically supported, thermal particles are lost along the field to the supports, and the plasma pressure is highly peaked and consists of energetic, mirror-trapped electrons that are created by electron cyclotron resonance heating. By contrast, when the dipole is magnetically levitated losses to the supports are eliminated and particles are lost via slower cross-field transport that results in broader, but still peaked, plasma pressure profiles. (paper)

  8. Collapse instability of solitons in the nonpolynomial Schroedinger equation with dipole-dipole interactions

    International Nuclear Information System (INIS)

    Gligoric, G; Hadzievski, Lj; Maluckov, A; Malomed, B A

    2009-01-01

    A model of the Bose-Einstein condensate (BEC) of dipolar atoms, confined in a combination of a cigar-shaped trap and optical lattice acting in the axial direction, is studied in the framework of the one-dimensional (1D) nonpolynomial Schroedinger equation (NPSE) with additional terms describing long-range dipole-dipole (DD) interactions. The NPSE makes it possible to describe the collapse of localized modes, which was experimentally observed in the self-attractive BEC confined in tight traps, in the framework of the 1D description. We study the influence of the DD interactions on the dynamics of bright solitons, especially concerning their collapse-induced instability. Both attractive and repulsive contact and DD interactions are considered. The results are summarized in the form of stability/collapse diagrams in a respective parametric space. In particular, it is shown that the attractive DD interactions may prevent the collapse instability in the condensate with attractive contact interactions.

  9. LHC Dipoles Accelerate

    CERN Multimedia

    2001-01-01

    Andrezej Siemko (left), Peter Sievers (centre), and Lucio Rossi (right), have the exciting challenge of preparing and testing 2000 magnets for the LHC. The LHC is going to require a lot of powerful magnets by the time it begins operation in 2006. More specifically, it is going to need 130 special magnets, 400 quadrupoles, and a whopping 1250 dipoles! Preparing and testing these magnets for the conditions they will encounter in the LHC is not an easy task. But evaluation of the most recently received magnet, from the German company Noell, is showing that while the monumental task of receiving and testing nearly 2000 magnets is going to be exhausting, the goals are definitely attainable. At the moment and over the next year, pre-series magnets (the magnets that CERN uses to fine tune performance) are arriving slowly (90 in total will arrive), but by 2003 the rate of series magnet arrival will accelerate to 9 per week, that's over 450 in a single year! And working with these magnets when they arrive is tough. ...

  10. Low-Q Electrically Small Spherical Magnetic Dipole Antennas

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.

    2010-01-01

    Three novel electrically small antenna configurations radiating a TE10 spherical mode corresponding to a magnetic dipole are presented and investigated: multiarm spherical helix (MSH) antenna, spherical split ring resonator (S-SRR) antenna, and spherical split ring (SSR) antenna. All three antennas...... are self-resonant, with the input resistance tuned to 50 ohms by an excitation curved dipole/monopole. A prototype of the SSR antenna has been fabricated and measured, yielding results that are consistent with the numerical simulations. Radiation quality factors (Q) of these electrically small antennas (in...

  11. Possible displacement of mercury's dipole

    International Nuclear Information System (INIS)

    Ng, K.H.; Beard, D.B.

    1979-01-01

    Earlier attempts to model the Hermean magnetospheric field based on a planet-centered magnetic multipole field have required the addition of a quadrupole moment to obtain a good fit to space vehicle observations. In this work we obtain an equally satisfactory fit by assuming a null quadrupole moment and least squares fitting of the displacement of the planetary dipole from the center of the planet. We find a best fit for a dipole displacement from the planet center of 0.033 R/sub m/ away from the solar direction, 0.025 R/sub m/ toward dawn in the magnetic equatorial plane, and 0.189 R/sub m/ northward along the magnetic dipole axis, where R/sub m/ is the planet radius. Therefore the presence of a magnetic quadrupole moment is not ruled out. The compressed dipole field more completely represents the field in the present work than in previous work where the intrinsic quadrupole field was not included in the magnetopause surface and field calculations. Moreover, we have corrected a programing error in previous work in the computation of dipole tilt lambda away from the sun. We find a slight increase for the planet dipole moment of 190γR/sub m/ 3 and a dipole tilt angle lambda away from the sun. We find a slight increase for the planet moment of 190γR/sub m/ 3 and a dipole tilt angle lambda of only 1.2 0 away from the sun. All other parameters are essentially unchanged

  12. Dipole Bands in 196Hg

    International Nuclear Information System (INIS)

    Lawrie, J. J.; Lawrie, E. A.; Newman, R. T.; Sharpey-Schafer, J. F.; Smit, F. D.; Msezane, B.; Benatar, M.; Mabala, G. K.; Mutshena, K. P.; Federke, M.; Mullins, S. M.; Ncapayi, N. J.; Vymers, P.

    2011-01-01

    High spin states in 196 Hg have been populated in the 198 Pt(α,6n) reaction at 65 MeV and the level scheme has been extended. A new dipole band has been observed and a previously observed dipole has been confirmed. Excitation energies, spins and parities of these bands were determined from DCO ratio and linear polarization measurements. Possible quasiparticle excitations responsible for these structures are discussed.

  13. A Note on the Dipole Coordinates

    OpenAIRE

    Kageyama, Akira; Sugiyama, Tooru; Watanabe, Kunihiko; Sato, Tetsuya

    2004-01-01

    A couple of orthogonal coordinates for dipole geometry are proposed for numerical simulations of plasma geophysics in the Earth's dipole magnetic field. These coordinates have proper metric profiles along field lines in contrast to the standard dipole coordinate system that is commonly used in analytical studies for dipole geometry.

  14. Statistical contribution in the giant multipolar resonance decay in hevay nuclei

    International Nuclear Information System (INIS)

    Teruya, N.

    1986-01-01

    Statistical calculations are made for the decay in the electric monopole giant resonance in 208 Pb and electric dipole giant resonance in 209 Bi, using the Hauser-Feshbach formalism. Calculations are done using the experimental energy levels of the corresponding residual nuclei. The particle-vibrator model is used for those experimental levels without spin and parity determination. The influence of different parametrizations of the optical potential in the statistical calculation result is also studied. (L.C.) [pt

  15. Overview and Status of the Levitated Dipole Experiment

    Science.gov (United States)

    Garnier, D. T.; Hansen, A. K.; Mauel, M. E.; Ortiz, E.; Sunn-Pedersen, T.; Dagen, S.; Ellsworth, J.; Karim, I.; Kesner, J.; Minervini, J.; Michael, P.; Zhukovsky, A.

    2002-11-01

    The Levitated Dipole Experiment (LDX) is the first experiment designed to study high-β plasmas confined by a magnetic dipole with near classical energy confinement. The primary goal of the initial phase of LDX operation is the study of plasma behavior near marginal stability for interchange modes at high-β. Other areas of investigation include dipole confinement characteristics, the formation of convective cells within the closed field line geometry and the possibility of non-local transport. LDX consists of three superconducting magnets and highlights the role of innovative magnetic technology that makes possible explorations of entirely new confinement concepts. We describe the LDX machine design and detail the fabrication status of the superconducting floating-coil, charging-coil, and levitation-coil as LDX nears plasma operations. An overview of the project goals, overall program plan, and current status of the experiment will also be presented.

  16. Nonperturbative study of the damping of giant resonances in hot nuclei

    International Nuclear Information System (INIS)

    De Blasio, F.V.; Cassing, W.; Tohyama, M.; Bortignon, P.F.; Broglia, R.A.

    1992-01-01

    The damping of dipole and quadrupole motion in 16 O and 40 Ca at zero and finite temperature is studied including particle-particle and particle-hole interactions to all orders of perturbation. We find that the dipole dynamics in these light nuclei is well described in terms of mean-field theory (time-dependent Hartree-Fock), while the quadrupole motion is strongly damped through the coupling to more complicated configurations. Both the centroid and the damping width of the quadrupole and dipole giant resonances show a clear stability with temperature as a consequence of the weakening of the interaction, which contrasts with the increase of the phase space

  17. The pygmy dipole resonance in neutron-rich nuclei

    International Nuclear Information System (INIS)

    Hung, Nguyen Quang; Kiet, Hoang Anh Tuan; Duc, Huynh Ngoc; Chuong, Nguyen Thi

    2016-01-01

    The pygmy dipole resonance (PDR), which has been observed via the enhancement of the electric dipole strength E 1 of atomic nuclei, is studied within a microscopic collective model. The latter employs the Hartree-Fock (HF) method with effective nucleon-nucleon interactions of the Skyrme types plus the random-phase approximation (RPA). The results of the calculations obtained for various even-even nuclei such as "1"6"-"2"8O, "4"0"-"5"8Ca, "1"0"0"-"1"2"0Sn, and "1"8"2"-"2"1"8Pb show that the PDR is significantly enhanced when the number of neutrons outside the stable core of the nucleus is increased, that is, in the neutron-rich nuclei. As the result, the relative ratio between the energy weighted sum of the strength of the PDR and that of the GDR (giant dipole resonance) does not exceed 4%. The collectivity of the PDR and GDR states will be also discussed. (paper)

  18. Destructive interference between electric and toroidal dipole moments in TiO2 cylinders and frustums with coaxial voids

    Science.gov (United States)

    Terekhov, P. D.; Baryshnikova, K. V.; Evlyukhin, A. B.; Shalin, A. S.

    2017-11-01

    We demonstrate numerically the possibility of multipole interference in the TiO2 (titanium dioxide) microcylinders and microfrustums in the wavelength range 210-300 μm. Resonantly strong destructive interference between toroidal and electric dipole contributions to the scattered field is achieved by a geometry tuning. The toroidal and electric dipole mode overlapping at the resonant wavelength with almost total suppression of the total electric dipole moment is achieved.

  19. Effects of dipole—dipole interaction on entanglement transfer

    International Nuclear Information System (INIS)

    Guo Hong; Xiong Hengna

    2008-01-01

    A system consisting of two different atoms interacting with a two-mode vacuum, where each atom is resonant only with one cavity mode, is considered. The effects of dipole—dipole (dd) interaction between two atoms on the atom-atom entanglement and mode-mode entanglement are investigated. For a weak dd interaction, when the atoms are initially separable, the entanglement between them can be induced by the dd interaction, and the entanglement transfer between the atoms and the modes occurs efficiently; when the atoms are initially entangled, the entanglement transfer is almost not influenced by the dd interaction. However, for a strong dd interaction, it is difficult to transfer the entanglement from the atoms to the modes, but the atom-atom entanglement can be maintained when the atoms are initially entangled

  20. Two-phonon giant resonances in 136Xe, 208Pb, and 238U

    International Nuclear Information System (INIS)

    Boretzky, K.; Gruenschloss, A.; Ilievski, S.; Adrich, P.; Aumann, T.; Bertulani, C.A.; Cub, J.; Dostal, W.; Eberlein, B.; Elze, T.W.; Emling, H.; Fallot, M.; Holeczek, J.; Holzmann, R.; Kozhuharov, C.; Kratz, J.V.; Kulessa, R.; Leifels, Y.; Leistenschneider, A.; Lubkiewicz, E.; Mordechai, S.; Ohtsuki, T.; Reiter, P.; Simon, H.; Stelzer, K.; Stroth, J.; Suemmerer, K.; Surowiec, A.; Wajda, E.; Walus, W.

    2003-07-01

    The excitation of the double-phonon giant dipole resonance was observed in heavy projectile nuclei impinging on targets of high nuclear charge with energies of 500-700 MeV/nucleon. New experimental data are presented for 136 Xe and 238 U together with further analysis of earlier data on 208 Pb. Differential cross sections dσ/dE * and dσ/dθ for electromagnetic excitations were deduced. Depending on the isotope, cross sections appear to be enhanced in comparison to those expected from a purely harmonic nuclear dipole response. The cumulative effect of excitations of two-phonon states composed of one dipole and one quadrupole phonon, of predicted anharmoniticies in the double-phonon dipole response, and of damping of the dipole resonance during the collision may account for the discrepancy. In addition, decay properties of two-phonon resonances were studied and compared to that of a statistical decay. (orig.)

  1. Dipole Resonances of 76Ge

    Science.gov (United States)

    Ilieva, R. S.; Cooper, N.; Werner, V.; Rusev, G.; Pietralla, N.; Kelly, J. H.; Tornow, W.; Yates, S. W.; Crider, B. P.; Peters, E.

    2013-10-01

    Dipole resonances in 76Ge have been studied using the method of Nuclear Resonance Fluorescence (NRF). The experiment was performed using the Free Electron Laser facility at HI γS/TUNL, which produced linearly polarised quasi-monoenergetic photons in the 4-9 MeV energy range. Photon strength, in particular dipole strength, is an important ingredient in nuclear reaction calculations, and recent interest in its study has been stimulated by observations of a pygmy dipole resonance near the neutron separation energy Sn of certain nuclei. Furthermore, 76Ge is a candidate for 0 ν 2 β -decay. The results are complimentary to a relevant experiment done at TU Darmstadt using Bremsstrahlung beams. Single-resonance parities and a preliminary estimate of the total photo-excitation cross section will be presented. This work was supported by the U.S. DOE under grant no. DE-FG02-91ER40609.

  2. Stacks of SPS Dipole Magnets

    CERN Multimedia

    1974-01-01

    Stacks of SPS Dipole Magnets ready for installation in the tunnel. The SPS uses a separated function lattice with dipoles for bending and quadrupoles for focusing. The 6.2 m long normal conducting dipoles are of H-type with coils that are bent-up at the ends. There are two types, B1 (total of 360) and B2 (384). Both are for a maximum field of 1.8 Tesla and have the same outer dimensions (450x800 mm2 vxh) but with different gaps (B1: 39x129 mm2, B2: 52x92 mm2) tailored to the beam size. The yoke, made of 1.5 mm thick laminations, consists of an upper and a lower half joined together in the median plane once the coils have been inserted.

  3. Cryogenics in CEBAF HMS dipole

    International Nuclear Information System (INIS)

    Bogensberger, P.; Ramsauer, F.; Brindza, P.; Wines, R.; Koefler, H.

    1994-01-01

    The paper will report upon the final design, manufacturing and tests of CEBAF's HMS Dipole cryogenic equipment. The liquid nitrogen circuits, the helium circuits and thermal insulation of the magnet will be addressed. The cryogenic reservoir and control module as an integral part of the HMS Dipole magnet will be presented. The construction, manufacturing, tests and final performance of the HMS Dipole cryogenic system will be reported. The LN 2 circuit and the He circuit are tied together by the control system for cool down, normal operation and standby. This system monitors proper temperature differences between both circuits and controls the cryogenic supply to meet the constraints. Implementation of the control features for the cryogenic system into the control system will be reported

  4. Derivation of the dipole map

    International Nuclear Information System (INIS)

    Ali, Halima; Punjabi, Alkesh; Boozer, Allen

    2004-01-01

    In our method of maps [Punjabi et al., Phy. Rev. Lett. 69, 3322 (1992), and Punjabi et al., J. Plasma Phys. 52, 91 (1994)], symplectic maps are used to calculate the trajectories of magnetic field lines in divertor tokamaks. Effects of the magnetic perturbations are calculated using the low MN map [Ali et al., Phys. Plasmas 11, 1908 (2004)] and the dipole map [Punjabi et al., Phys. Plasmas 10, 3992 (2003)]. The dipole map is used to calculate the effects of externally located current carrying coils on the trajectories of the field lines, the stochastic layer, the magnetic footprint, and the heat load distribution on the collector plates in divertor tokamaks [Punjabi et al., Phys. Plasmas 10, 3992 (2003)]. Symplectic maps are general, efficient, and preserve and respect the Hamiltonian nature of the dynamics. In this brief communication, a rigorous mathematical derivation of the dipole map is given

  5. Coupled-resonator waveguide perfect transport single-photon by interatomic dipole-dipole interaction

    Science.gov (United States)

    Yan, Guo-an; Lu, Hua; Qiao, Hao-xue; Chen, Ai-xi; Wu, Wan-qing

    2018-06-01

    We theoretically investigate single-photon coherent transport in a one-dimensional coupled-resonator waveguide coupled to two quantum emitters with dipole-dipole interactions. The numerical simulations demonstrate that the transmission spectrum of the photon depends on the two atoms dipole-dipole interactions and the photon-atom couplings. The dipole-dipole interactions may change the dip positions in the spectra and the coupling strength may broaden the frequency band width in the transmission spectrum. We further demonstrate that the typical transmission spectra split into two dips due to the dipole-dipole interactions. This phenomenon may be used to manufacture new quantum waveguide devices.

  6. Electrified BPS giants: BPS configurations on giant gravitons with static electric field

    International Nuclear Information System (INIS)

    Ali-Akbari, Mohammad; Sheikh-Jabbari, Mohammad Mahdi

    2007-01-01

    We consider D3-brane action in the maximally supersymmetric type IIB plane-wave background. Upon fixing the light-cone gauge, we obtain the light-cone Hamiltonian which is manifestly supersymmetric. The 1/2 BPS solutions of this theory (solutions which preserve 16 supercharges) are either of the form of spherical three branes, the giant gravitons, or zero size point like branes. We then construct specific classes of 1/4 BPS solutions of this theory in which static electric field on the brane is turned on. These solutions are deformations about either of the two 1/2 BPS solutions. In particular, we study in some detail 1/4 BPS configurations with electric dipole on the three sphere giant, i.e. BIons on the giant gravitons, which we hence call BIGGons. We also study BPS configurations corresponding to turning on a background uniform constant electric field. As a result of this background electric field the three sphere giant is deformed to squashed sphere, while the zero size point like branes turn into circular or straight fundamental strings in the plane-wave background, with their tension equal to the background electric field

  7. Scattering cross section of unequal length dipole arrays

    CERN Document Server

    Singh, Hema; Jha, Rakesh Mohan

    2016-01-01

    This book presents a detailed and systematic analytical treatment of scattering by an arbitrary dipole array configuration with unequal-length dipoles, different inter-element spacing and load impedance. It provides a physical interpretation of the scattering phenomena within the phased array system. The antenna radar cross section (RCS) depends on the field scattered by the antenna towards the receiver. It has two components, viz. structural RCS and antenna mode RCS. The latter component dominates the former, especially if the antenna is mounted on a low observable platform. The reduction in the scattering due to the presence of antennas on the surface is one of the concerns towards stealth technology. In order to achieve this objective, a detailed and accurate analysis of antenna mode scattering is required. In practical phased array, one cannot ignore the finite dimensions of antenna elements, coupling effect and the role of feed network while estimating the antenna RCS. This book presents the RCS estimati...

  8. On some aspects of the semiclassical approach to giant resonances of rotating nuclei

    International Nuclear Information System (INIS)

    Winter, J.

    1985-01-01

    Quadrupole and isovector dipole resonances of rotating nuclei are investigated in the frame-work of Vlasov equations transformed to a rotating system of reference, which are based on the time-dependent Hartree-method for schematic forces. The parameter free model of the self-consistent vibrating harmonic oscillator potential for the quadrupole mode is extended to a coupling to rotation, which also includes large amplitude behaviour. A generalization to an exactly solvable two-liquid model describing the isovector mode is established; for rotating nuclei Hilton's explicit result for the eigenfrequencies is obtained. - The advantage of using the concept of the classical kinetic momentum in a rotating system also in quantum-mechanical descriptions is demonstrated. It completes the standard transformation of density matrices by a time-odd part realized in a phase-factor and permits a more direct interpretation of rotation effects in terms of the classical forces of inertia. - In its generalization from constant angular velocity to constant angular momentum, our model is used to demonstrate that cranking calculations of rotating giant resonances should be corrected for an oscillation of the cranking parameter to assure angular-momentum conservation. (orig.)

  9. Nanodielectrics with giant permittivity

    Indian Academy of Sciences (India)

    Following the prediction, during the last couple of years we have investigated the effect of giant permittivity in one-dimensional systems of conventional metals and conjugated polymer chains. In this article, we have tried to summarize the works on giant permittivity and finally the fabrication of nanocapacitor using metal ...

  10. Active filter for the DESY III dipole circuit

    International Nuclear Information System (INIS)

    Bothe, W.

    1991-01-01

    The DESY 3 dipole circuit is now operated in a ramp mode cycle with 3.6 s repetition rate. Excitation is done by a 12-pulse thyristor converter, followed by a passive filter. The existing current control could be improved by addition of an active filter. The use of a more efficient passive filter reduces the size of the active filter and does not deteriorate the dynamic behavior. The design of the control loops and the results of the simulation are presented

  11. Raising the last LEP dipole

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    The last of the 3280 dipole magnets from the Large Electron-Positron (LEP) collider is seen on its journey to the surface on 12 February 2002. The LEP era, which began at CERN in 1989 and ended 2000, comes to an end.

  12. Locating a buried magnetic dipole

    Energy Technology Data Exchange (ETDEWEB)

    Caffey, T.W.H.

    1977-01-01

    The theoretical basis and required computations for locating a buried magnetic dipole are outlined. The results are compared with measurements made with a tiltable coil lowered to a depth of 20 m in a vertical borehole within a three-layered earth. this work has application to the rescue of trapped miners. 3 figures, 1 table. (RWR)

  13. Particle electric dipole-moments

    Energy Technology Data Exchange (ETDEWEB)

    Pendlebury, J M [Sussex Univ., Brighton (United Kingdom)

    1997-04-01

    The incentive to detect particle electric dipole-moments, as a window on time-reversal violation, remains undiminished. Efforts to improve the measurements for the neutron, the electron and some nuclei are still making rapid progress as more powerful experimental methods are brought to bear. A new measurement for the neutron at ILL is presented. (author). 7 refs.

  14. 5cm aperture dipole studies

    International Nuclear Information System (INIS)

    McInturff, A.D.; Bossert, R.; Carson, J.; Fisk, H.E.; Hanft, R.; Kuchnir, M.; Lundy, R.; Mantech, P.; Strait, J.

    1986-01-01

    The results obtained during the evolution of the design, construction, and testing program of the design ''B'' dipole are presented here. Design ''B'' is one of the original three competing designs for the Superconducting Super Collider ''SSC'' arc dipoles. The final design parameters were as follows: air cored (less than a few percent of the magnetic field derived from any iron present), aluminum collared, two layered winding, 5.5T maximum operating field, and a 5 cm cold aperture. There have been fourteen 64 cm long 5 cm aperture model dipoles cold tested (at 4.3K and less) in this program so far. There was a half length full size (6m) mechanical analog (M-10) built and tested to check the cryostat's mechanical design under ramping and quench conditions. Several deviations from the ''Tevatron'' dipole fabrication technique were incorporated, for example the use of aluminum collars instead of stainless steel. The winding technique variations explored were ''dry welding,'' a technique with the cable covered with Kapton insulation only and ''wet winding'' where the Kapton was covered with a light coat of ''B'' stage epoxy. Test data include quench currents, field quality (Fourier multipole co-efficients), coil magnetization, conductor current performance, and coil loading. Quench current, loss per cycle, and harmonics were measured as a function of the magnitude and rate of change of the magnetic field, and helium bath temperature

  15. The Collider dipole magnet program

    International Nuclear Information System (INIS)

    Baldi, R.W.; Bailey, R.; Bever, D.; Bogart, L.; Gigg, G.; Packer, M.; Page, L.; Stranberg, N.

    1991-01-01

    The Superconducting Super Collider will consist of more large superconducting magnets than have been built to date. Over 12,000 superconducting magnets are required and more than 8,000 will be Collider dipoles. The dipole magnet program is on the critical path of the project and requires the optimized utilization of the Nation's resources - National Laboratories, Universities and Industry. General Dynamics and Westinghouse Electric Corporation have been chosen as the Leader and Follower companies for the design of producible magnets and the manufacturing of the SSC dipoles. Industry has the necessary experience, skills and facilities required to produce reliable and cost effective dipole magnets. At peak production, 10 CDMs per day, very large quantities (nearly 130 metric tonnes/day) of materials will have to be procured from companies nationwide and fabricated into defect-free magnets. A key element of the SSCL's strategy to produce the most efficient CDM program is to employ the Leader-Follower approach, with the Leader transferring technology from the laboratories to the Leader's facility, fully integrating the Follower in the producibility and tooling/factory design efforts, and assisting the Follower in magnet qualification tests. General Dynamics is ready to help build America's most powerful research tool. Management is in place, the facilities are ready for activation and resources are available for immediate assignment

  16. A Tale of Two Dipoles

    DEFF Research Database (Denmark)

    Andersen, Jørgen Bach

    2006-01-01

    A number of antenna topics may be treated by studying just two parallel, closely spaced electrical dipoles. They form an array and they may be coupled to form a single antenna with one port, or coupled through a coupling network to form a multiport antenna. The situations discussed are the creation...

  17. Dipole and spin-dipole strength distributions in isotopes

    Indian Academy of Sciences (India)

    Necla Cakmak

    2018-01-03

    Jan 3, 2018 ... isotopes. NECLA CAKMAK1, SADIYE CAKMAK2, CEVAD SELAM3 and SERDAR UNLU4,∗. 1Department of Physics, Karabuk University, Karabuk, Turkey. 2Department of Physics ... and 14 and the giant resonances in the energy region of. 19–27 MeV were ... even–even nuclei [21]. The restoration of this ...

  18. Multiscale dipole relaxation in dielectric materials

    DEFF Research Database (Denmark)

    Hansen, Jesper Schmidt

    2016-01-01

    Dipole relaxation from thermally induced perturbations is investigated on different length scales for dielectric materials. From the continuum dynamical equations for the polarisation, expressions for the transverse and longitudinal dipole autocorrelation functions are derived in the limit where ...

  19. Dipole rescattering and the nuclear structure function

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, F. [Depto de Ciencias Exatas e da Terra, Universidade Federal de Sao Paulo, SP (Brazil); Goncalves, V. P. [Instituto de Fisica e Matematica, Universidade Federal de Pelotas, Caixa Postal 354, CEP 96010-900, Pelotas, RS (Brazil); Navarra, F. S.; Oliveira, E. G. [Instituto de Fisica, Universidade de Sao Paulo Rua do Matao, Travessa R, 187, 05508-090 Sao Paulo, SP (Brazil)

    2013-03-25

    In the framework of the dipole model, we study the effects of the dipole multiple scatterings in a nuclear target and compute the nuclear structure function. We compare different unitarization schemes and confront our results with the E665 data.

  20. New bound on neutrino dipole moments from globular-cluster stars

    Science.gov (United States)

    Raffelt, Georg G.

    1990-01-01

    Neutrino dipole moments mu(nu) would increase the core mass of red giants at the helium flash by delta(Mc) = 0.015 solar mass x mu(nu)/10 to the -12th muB (where muB is the Bohr magneton) because of enhanced neutrino losses. Existing measurements of the bolometric magnitudes of the brightest red giants in 26 globular clusters, number counts of horizontal-branch stars and red giants in 15 globular clusters, and statistical parallax determinations of field RR Lyr luminosities yield delta(Mc) = 0.009 + or - 0.012 solar mass, so that conservatively mu(nu) is less than 3 x 10 to the -12th muB.

  1. Dynamics of a nonlinear dipole vortex

    DEFF Research Database (Denmark)

    Hesthaven, J.S.; Lynov, Jens-Peter; Nielsen, A.H.

    1995-01-01

    A localized stationary dipole solution to the Euler equations with a relationship between the vorticity and streamfunction given as omega=-psi+psi(3) is presented. By numerical integration of the Euler equations this dipole is shown to be unstable. However, the initially unstable dipole reorganiz...

  2. Formation of dislocation dipoles in irradiated graphite

    International Nuclear Information System (INIS)

    Niwase, Keisuke

    2005-01-01

    Recently, we have proposed a dislocation dipole accumulation model to explain the irradiation-induced amorphization of graphite. However, the structure of dislocation dipole in the hexagonal networks is still an open question at the atomic-level. In this paper, we propose a possible formation process of the dislocation dipole

  3. Polarization electric dipole moment in nonaxial nuclei

    International Nuclear Information System (INIS)

    Denisov, V.Yu.; Davidovskaya, O.I.

    1996-01-01

    An expression for the macroscopic polarization electric dipole moment is obtained for nonaxial nuclei whose radii of the proton and neutron surfaces are related by a linear equation. Dipole transitions associated with the polarization electric dipole moment are analyzed for static and dynamical multipole deformations

  4. Tightly confined atoms in optical dipole traps

    International Nuclear Information System (INIS)

    Schulz, M.

    2002-12-01

    This thesis reports on the design and setup of a new atom trap apparatus, which is developed to confine few rubidium atoms in ultrahigh vacuum and make them available for controlled manipulations. To maintain low background pressure, atoms of a vapour cell are transferred into a cold atomic beam by laser cooling techniques, and accumulated by a magneto-optic trap (MOT) in a separate part of the vacuum system. The laser cooled atoms are then transferred into dipole traps made of focused far-off-resonant laser fields in single- or crossed-beam geometry, which are superimposed with the center of the MOT. Gaussian as well as hollow Laguerre-Gaussian (LG$ ( 01)$) beam profiles are used with red-detuned or blue-detuned light, respectively. Microfabricated dielectric phase objects allow efficient and robust mode conversion of Gaussian into Laguerre-Gaussian laser beams. Trap geometries can easily be changed due to the highly flexible experimental setup. The dipole trap laser beams are focused to below 10 microns at a power of several hundred milliwatts. Typical trap parameters, at a detuning of several ten nanometers from the atomic resonance, are trag depths of few millikelvin, trap frequencies near 30-kHz, trap light scattering rates of few hundred photons per atom and second, and lifetimes of several seconds. The number of dipole-trapped atoms ranges from more than ten thousand to below ten. The dipole-trapped atoms are detected either by a photon counting system with very efficient straylight discrimination, or by recapture into the MOT, which is imaged onto a sensitive photodiode and a CCD-camera. Due to the strong AC-Stark shift imposed by the high intensity trapping light, energy-selective resonant excitation and detection of the atoms is possible. The measured energy distribution is consistent with a harmonic potential shape and allows the determination of temperatures and heating rates. In first measurements, the thermal energy is found to be about 10 % of the

  5. Giant 4p-quadrupole resonances in the Rare Earths

    International Nuclear Information System (INIS)

    Matthew, J.A.D.; Netzer, F.P.; Clark, C.W.; Morar, J.F.

    1987-01-01

    X-ray absorption of Ce obtained by partial secondary yield, is compared with previously obtained electron-energy loss measurements in reflection mode. The absence of a strong feature below 4p 3/2 threshold in photon absorption provides confirmation that the peak in EELS is nondipole in character. Theoretical analysis supports interpretation in terms of a p-f giant quadrupole resonance, a result which broadens the analogy between giant resonances in atomic and nuclear physics

  6. Magnetisation of magnetite nanoparticles medium with dipol-dipol interaction

    International Nuclear Information System (INIS)

    Ali-zade, R. A.

    2005-01-01

    Full text: Magnetisation expression for magnetite nanoparticles medium with dipo-dipol interaction has been obtained. We suggested, that energy magnetic dipol-dipol interaction of magnetite nanopaticles is determined by: E d-d = - m 2 /4πμ 0 r 3 (cth x -1/x) 2 where x=mH/kT. This expression has been substituted in statistical sum of magnetite nanoparticles medium. Obtained statistical sum consists the production of two statistical sums. The first statistical sum described non-interacting magnetite nanoparticle medium and from this is obtained Langevan equation. Second statistical sum is: Z 2 -∫exp(Σm 2 /4π 0 r 3 (cth x -1/x) 2 ) dΩ 2 . The second statistical sum has been expanded in Taylor's set and taken into consideration first two terms. Integration has been carried out over all volume. In this case take into account that, number twice interactions of magnetite nanoparticles in unit volume is equal to N(N-1)/2 at N>>1 to N 2 /2. We obtain expressions for magnetisation and initial magnetic susceptibility of interacting magnetite nanoparticles medium take into account that Φ=-kT ln Z, M=-dΦ/dH, χ=dM/dH: M=M Sφm (cth x -1/x)+ 1/3 M S 2 φ m 2 (1μ 0 H) ln(VM S /kT).(cth x -1/x)(-xcsch 2 x+1/x) χ 0 =1/3 (m/kT)+ 1/27 M S 2 φ m 2 (1μ 0 )ln(VM S /kT).(m/kT) 2 . Second term in the magnetisation is sufficient at weak and middle magnetic fields. At large magnetic fields, it leads to zero. The second term of magnetisation has maximum at x=1.566. The values of experimental and calculated magnetic field corresponding to magnetisation maximum for magnetite nanoparticles medium (mean diameter of nanoparticle is 9.4 nm) are 1.19 10 4 A/m and 1.25 10 4 A/m respectively. Magnetic dipol-dipol interaction influence to magnetisation of magnetite nanoparticles. Magnetite nanoparticles lined along external magnetic fields line and formatted chains. Magnetisation of medium occurs by the 'parallel' mechanism method magnetisation of chains

  7. Double-mode pulsation

    International Nuclear Information System (INIS)

    Cox, A.N.

    1982-01-01

    Double mode pulsation is a very pervasive phenomenon in stars all over the Hertzsprung-Russell diagram. In order of increasing radius, examples are: ZZ Ceti stars, the sun, the delta Scuti stars, RR Lyrae variables, the β Cephei variables and those related to them, Cepheids, and maybe even the Mira stars. These many modes have been interpreted as both radial and nonradial modes, but in many cases the actual mode has not been clearly identified. Yellow giants seem to be the most simple pulsators with a large majority of the RR Lyrae variables and Cepheids showing only one pulsation period. We limit this review to those very few cases for classical Cepheids and RR Lyrae variables which display two modes. For these we know many facts about these stars, but the actual cause of the pulsation in two modes simultaneously remains unknown

  8. Aperture measurements with AC dipole

    CERN Document Server

    Fuster Martinez, Nuria; Dilly, Joschua Werner; Nevay, Laurence James; Bruce, Roderik; Tomas Garcia, Rogelio; Redaelli, Stefano; Persson, Tobias Hakan Bjorn; CERN. Geneva. ATS Department

    2018-01-01

    During the MDs performed on the 15th of September and 29th of November 2017, we measured the LHC global aperture at injection with a new AC dipole method as well as using the Transverse Damper (ADT) blow-up method used during the 2017 LHC commissioning for benchmarking. In this note, the MD procedure is presented as well as the analysis of the comparison between the two methods. The possible benefits of the new method are discussed.

  9. Electric Dipole Moments of Hadrons

    OpenAIRE

    Wirzba, Andreas

    2016-01-01

    A nonzero electric dipole moment (EDM) of the neutron, proton, deuteron, helion or any finite system necessarily involves the breaking of a symmetry, either by the presence of external fields (leading to the case of induced EDMs) or explicitly by the breaking of the discrete parity and time-reflection symmetries in the case of permanent EDMs. Recent - and in the case of the deuteron even unpublished - results for the relevant matrix elements of nuclear EDM operators are presented and the rel...

  10. Dipole-induced exchange bias.

    Science.gov (United States)

    Torres, Felipe; Morales, Rafael; Schuller, Ivan K; Kiwi, Miguel

    2017-11-09

    The discovery of dipole-induced exchange bias (EB), switching from negative to positive sign, is reported in systems where the antiferromagnet and the ferromagnet are separated by a paramagnetic spacer (AFM-PM-FM). The magnitude and sign of the EB is determined by the cooling field strength and the PM thickness. The same cooling field yields negative EB for thin spacers, and positive EB for thicker ones. The EB decay profile as a function of the spacer thickness, and the change of sign, are attributed to long-ranged dipole coupling. Our model, which accounts quantitatively for the experimental results, ignores the short range interfacial exchange interactions of the usual EB theories. Instead, it retains solely the long range dipole field that allows for the coupling of the FM and AFM across the PM spacer. The experiments allow for novel switching capabilities of long range EB systems, while the theory allows description of the structures where the FM and AFM are not in atomic contact. The results provide a new approach to design novel interacting heterostructures.

  11. Lipase polystyrene giant amphiphiles.

    Science.gov (United States)

    Velonia, Kelly; Rowan, Alan E; Nolte, Roeland J M

    2002-04-24

    A new type of giant amphiphilic molecule has been synthesized by covalently connecting a lipase enzyme headgroup to a maleimide-functionalized polystyrene tail (40 repeat units). The resulting biohybrid forms catalytic micellar rods in water.

  12. Metaphyseal giant cell tumor

    International Nuclear Information System (INIS)

    Pereira, L.F.; Hemais, P.M.P.G.; Aymore, I.L.; Carmo, M.C.R. do; Cunha, M.E.P.R. da; Resende, C.M.C.

    1986-01-01

    Three cases of metaphyseal giant cell tumor are presented. A review of the literature is done, demostrating the lesion is rare and that there are few articles about it. Age incidence and characteristics of the tumor are discussed. (Author) [pt

  13. Giant CP stars

    International Nuclear Information System (INIS)

    Loden, L.O.; Sundman, A.

    1989-01-01

    This study is part of an investigation of the possibility of using chemically peculiar (CP) stars to map local galactic structure. Correct luminosities of these stars are therefore crucial. CP stars are generally regarded as main-sequence or near-main-sequence objects. However, some CP stars have been classified as giants. A selection of stars, classified in literature as CP giants, are compared to normal stars in the same effective temperature interval and to ordinary 'non giant' CP stars. There is no clear confirmation of a higher luminosity for 'CP giants', than for CP stars in general. In addition, CP characteristics seem to be individual properties not repeated in a component star or other cluster members. (author). 50 refs., 5 tabs., 3 figs

  14. Features of the giant E1 resonance

    International Nuclear Information System (INIS)

    Bergere, R.

    1976-01-01

    Since most of the available experimental data concerning the giant dipole E1 resonance (GDR) have been obtained with real photons, the characteristics of real photon sources are reviewed with an attempt to connect the experimental particularities of each of them to the specific parameters of the GDR which it is best suited to reach. Some systematic properties gathered from experimental data of GDR (average energy, splitting and broadening of the GDR) are compared with the predictions of the static and dynamic collective models of the nuclei. The position in energy and the fine structure of the GDR are more closely connected to shell model predictions as nuclei get lighter, the various experimental integrated cross sections being also more easily understood by comparisons with microscopic models. Most of the reported data refer to the doorway state through which GDR is excited, however the competition between the decay channels for GDR states is also emphasized

  15. Constraining the neutrino magnetic dipole moment from white dwarf pulsations

    International Nuclear Information System (INIS)

    Córsico, A.H.; Althaus, L.G.; Bertolami, M.M. Miller; Kepler, S.O.; García-Berro, E.

    2014-01-01

    Pulsating white dwarf stars can be used as astrophysical laboratories to constrain the properties of weakly interacting particles. Comparing the cooling rates of these stars with the expected values from theoretical models allows us to search for additional sources of cooling due to the emission of axions, neutralinos, or neutrinos with magnetic dipole moment. In this work, we derive an upper bound to the neutrino magnetic dipole moment (μ ν ) using an estimate of the rate of period change of the pulsating DB white dwarf star PG 1351+489. We employ state-of-the-art evolutionary and pulsational codes which allow us to perform a detailed asteroseismological period fit based on fully DB white dwarf evolutionary sequences. Plasmon neutrino emission is the dominant cooling mechanism for this class of hot pulsating white dwarfs, and so it is the main contributor to the rate of change of period with time (Pidot) for the DBV class. Thus, the inclusion of an anomalous neutrino emission through a non-vanishing magnetic dipole moment in these sequences notably influences the evolutionary timescales, and also the expected pulsational properties of the DBV stars. By comparing the theoretical Pidot value with the rate of change of period with time of PG 1351+489, we assess the possible existence of additional cooling by neutrinos with magnetic dipole moment. Our models suggest the existence of some additional cooling in this pulsating DB white dwarf, consistent with a non-zero magnetic dipole moment with an upper limit of μ ν  ∼< 10 -11  μ B . This bound is somewhat less restrictive than, but still compatible with, other limits inferred from the white dwarf luminosity function or from the color-magnitude diagram of the Globular cluster M5. Further improvements of the measurement of the rate of period change of the dominant pulsation mode of PG 1351+489 will be necessary to confirm our bound

  16. RHIC spin flipper AC dipole controller

    Energy Technology Data Exchange (ETDEWEB)

    Oddo, P.; Bai, M.; Dawson, C.; Gassner, D.; Harvey, M.; Hayes, T.; Mernick, K.; Minty, M.; Roser, T.; Severino, F.; Smith, K.

    2011-03-28

    The RHIC Spin Flipper's five high-Q AC dipoles which are driven by a swept frequency waveform require precise control of phase and amplitude during the sweep. This control is achieved using FPGA based feedback controllers. Multiple feedback loops are used to and dynamically tune the magnets. The current implementation and results will be presented. Work on a new spin flipper for RHIC (Relativistic Heavy Ion Collider) incorporating multiple dynamically tuned high-Q AC-dipoles has been developed for RHIC spin-physics experiments. A spin flipper is needed to cancel systematic errors by reversing the spin direction of the two colliding beams multiple times during a store. The spin flipper system consists of four DC-dipole magnets (spin rotators) and five AC-dipole magnets. Multiple AC-dipoles are needed to localize the driven coherent betatron oscillation inside the spin flipper. Operationally the AC-dipoles form two swept frequency bumps that minimize the effect of the AC-dipole dipoles outside of the spin flipper. Both AC bumps operate at the same frequency, but are phase shifted from each other. The AC-dipoles therefore require precise control over amplitude and phase making the implementation of the AC-dipole controller the central challenge.

  17. Electrostatic stability of electron-positron plasmas in dipole geometry

    Science.gov (United States)

    Mishchenko, Alexey; Plunk, Gabriel G.; Helander, Per

    2018-04-01

    The electrostatic stability of electron-positron plasmas is investigated in the point-dipole and Z-pinch limits of dipole geometry. The kinetic dispersion relation for sub-bounce-frequency instabilities is derived and solved. For the zero-Debye-length case, the stability diagram is found to exhibit singular behaviour. However, when the Debye length is non-zero, a fluid mode appears, which resolves the observed singularity, and also demonstrates that both the temperature and density gradients can drive instability. It is concluded that a finite Debye length is necessary to determine the stability boundaries in parameter space. Landau damping is investigated at scales sufficiently smaller than the Debye length, where instability is absent.

  18. Monopole Giant Resonances and TDHF boundary conditions

    International Nuclear Information System (INIS)

    Stevenson, P.D.; Almehed, D.; Reinhard, P.-G.; Maruhn, J.A.

    2007-01-01

    Using time-dependent Hartree-Fock, we induce isoscalar and isovector monopole vibrations and follow the subsequent vibrations of both the same and opposite isospin nature in the N Z nucleus 132 Sn. By suitable scaling of the proton and neutron parts of the excitation operators, the coupling between the modes is studied, and the approximate normal modes found. Chaotic dynamics are then analysed in the isoscalar giant monopole resonance by using reflecting boundaries in a large space to build up a large number of 0 + states whose spacings are then analysed. A Wigner-like distribution is found

  19. Superconducting multi-cell trapped mode deflecting cavity

    Science.gov (United States)

    Lunin, Andrei; Khabiboulline, Timergali; Gonin, Ivan; Yakovlev, Vyacheslav; Zholents, Alexander

    2017-10-10

    A method and system for beam deflection. The method and system for beam deflection comprises a compact superconducting RF cavity further comprising a waveguide comprising an open ended resonator volume configured to operate as a trapped dipole mode; a plurality of cells configured to provide a high operating gradient; at least two pairs of protrusions configured for lowering surface electric and magnetic fields; and a main power coupler positioned to optimize necessary coupling for an operating mode and damping lower dipole modes simultaneously.

  20. Electric dipole polarizability from first principles calculations

    International Nuclear Information System (INIS)

    Miorelli, M.; University of British Columbia, Vancouver, BC; Bacca, S.; University of Manitoba; Barnea, N.

    2016-01-01

    The electric dipole polarizability quantifies the low-energy behavior of the dipole strength and is related to critical observables such as the radii of the proton and neutron distributions. Its computation is challenging because most of the dipole strength lies in the scattering continuum. In our paper we combine integral transforms with the coupled-cluster method and compute the dipole polarizability using bound-state techniques. Furthermore, employing different interactions from chiral effective field theory, we confirm the strong correlation between the dipole polarizability and the charge radius, and study its dependence on three-nucleon forces. Finally, we find good agreement with data for the 4 He, 40 Ca, and 16 O nuclei, and predict the dipole polarizability for the rare nucleus 22 O.

  1. CERN LHC dipole prototype success

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    In a crash programme, the first prototype superconducting dipole magnet for CERN's LHC protonproton collider was successfully powered for the first time at CERN on 14 April, eventually sailing to 9T, above the 8.65T nominal LHC field, before quenching for the third time. The next stage is to install the delicate measuring system for making comprehensive magnetic field maps in the 10 m long, 50 mm diameter twin-apertures of the magnet. These measurements will check that the required LHC field quality has been achieved at both the nominal and injection fields

  2. Alternative dipole magnets for ISABELLE

    Science.gov (United States)

    Taylor, C.; Althaus, R.; Caspi, S.; Gilbert, W.; Hassenzahl, W. V.; Meuser, R.; Rechen, J.; Warren, R.

    1982-05-01

    A dipole magnet, intended as a possible alternative for the ISABELLE main ring magnet, was designed. Three layers of FNAL Doubler/Saver conductor were used. Two 1.3-m-long models were built and tested, both with and without an iron core, and in both helium I and helium II. The training behavior, cyclic energy loss, point of quench initiation, and quench velocity were determined. A central field of 6.5 tesla was obtained in He I (4.4 K), and 7.6 tesla in He II (1.8K).

  3. Electric and Magnetic Dipole Moments

    CERN Document Server

    CERN. Geneva

    2005-01-01

    The stringent limit on the electric dipole moment of the neutron forced the issue on the strong CP-problem. The most elegant solution of which is the axion field proposed by Peccei and Quinn. The current limit on the QCD parameter theta coming from the limit on the neutron EDM is of order 10-10. I am going to describe the present status on the neutron EDM searches and further prospects on getting down to theta_qcd sensitivity of 10-13 with the new deuteron EDM in storage rings proposal. For completeness the current status and prospects of the muon g-2 experiment will also be given.

  4. The Muon Electric Dipole Moment

    OpenAIRE

    Barger, Vernon; Kao, Chung; Das, Ashok

    1997-01-01

    The electric dipole moment of the muon ($d_\\mu$) is evaluated in a two Higgs doublet model with a softly broken discrete symmetry. For $\\tan\\beta \\equiv |v_2|/|v_1| \\sim 1$, contributions from two loop diagrams involving the $t$ quark and the $W$ boson dominate; while for $\\tan\\beta \\gsim 10$, contributions from two loop diagrams involving the $b$ quark and the $\\tau$ lepton are dominant. For $8 \\gsim \\tan\\beta \\gsim 4$, significant cancellation occurs among the contributions from two loop di...

  5. Permanent Magnet Dipole for DIRAC Design Report

    CERN Document Server

    Vorozhtsov, Alexey

    2012-01-01

    Two dipole magnets including one spare unit are needed for the for the DIRAC experiment. The proposed design is a permanent magnet dipole. The design based on Sm2Co17 blocks assembled together with soft ferromagnetic pole tips. The magnet provides integrated field strength of 24.6 10-3 T×m inside the aperture of 60 mm. This Design Report summarizes the main magnetic and mechanic design parameters of the permanent dipole magnets.

  6. Electric dipole moment of diatomic molecules

    International Nuclear Information System (INIS)

    Rosato, A.

    1983-01-01

    The electric dipole moment of some diatomic molecules is calculated using the Variational Cellular Method. The results obtained for the molecules CO, HB, HF and LiH are compared with other calculations and with experimental data. It is shown that there is strong dependence of the electric dipole moment with respect to the geometry of the cells. It is discussed the possibility of fixing the geometry of the problem by giving the experimental value of the dipole moment. (Author) [pt

  7. SSC collider dipole magnet end mechanical design

    International Nuclear Information System (INIS)

    Delchamps, S.W.; Bossert, R.C.; Carson, J.; Ewald, K.; Fulton, H.; Kerby, J.; Koska, W.; Strait, J.; Wake, M.; Leung, K.K.

    1991-01-01

    This paper describes the mechanical design of the ends of Superconducting Super Collider dipole magnets to be constructed and tested at Fermilab. Coil end clamps, end yoke configuration, and end plate design are discussed. Loading of the end plate by axial Lorentz forces is discussed. Relevant data from 40 mm and 50 mm aperture model dipole magnets built and tested at Fermilab are presented. In particular, the apparent influence of end clamp design on the quench behavior of model SSC dipoles is described

  8. Electric dipole moment of diatomic molecules

    International Nuclear Information System (INIS)

    Rosato, A.

    1983-01-01

    The electric dipole moment of some diatomic molecules is calculated using the Variational Cellular Method. The results obtained for the CO, HB, HF and LiH molecules are compared with other calculations and with experimental data. It is shown that there is strong dependence of the electric dipole moment with respect to the geometry of the cells. The possibility of fixing the geometry of the problem by giving the experimental value of the dipole moment is discussed. (Author) [pt

  9. W-boson electric dipole moment

    International Nuclear Information System (INIS)

    He, X.; McKellar, B.H.J.

    1990-01-01

    The W-boson electric dipole moment is calculated in the SU(3) C xSU(2) L xU(1) Y model with several Higgs-boson doublets. Using the constraint on the CP-violating parameters from the experimental upper bound of the neutron electric dipole moment, we find that the W-boson electric dipole moment is constrained to be less than 10 -4

  10. Excitation of giant monopole and quadrupole resonances

    Energy Technology Data Exchange (ETDEWEB)

    Ogata, H. [Osaka Univ., Suita (Japan). Research Center for Nuclear Physics; Yamagata, T.; Tanaka, M. [and others; Ikegami, H.; Muraoka, M. [eds.; Osaka Univ., Suita (Japan). Research Center for Nuclear Physics

    1980-01-01

    Recent studies on the giant monopole resonance (GMR) and the giant quadrupole resonance (GQR) in /sup 144/Sm and /sup 208/Pb using the ..cap alpha..-scattering performed at RCNP are summarized. The observed angular range covered 1.6/sup 0/ -- 7/sup 0/ with a coupled system of a dipole and a triplet quadrupole magnet. The incident energy was changed from 84 to 119 MeV. The resonance shapes and energy-weighted sum-rule strengths of the GMR and the GQR were reliably deduced as a function of incident energy. The quadrupole strength of --20% was found in the GMR region. The observed excitation function of the GMR was compared with the DWBA calculation, in which the Satchler's Version I was used as a form factor representing the compressional motion of the nucleus. It was found that the experimental excitation function of the GMR shows steeper decrease as lowering the incident energy than the DWBA prediction whereas that of the GQR is successfully described by the DWBA. This suggests that examination of the model describing the GMR is necessary.

  11. The dipole-dipole dispersion forces for small, intermediate and large distances

    International Nuclear Information System (INIS)

    Antonio, J.C.

    1986-10-01

    An improved expression is obtained for the dipole-dipole London dispersion force between closed shell atoms for small, intermediate and large distances compared with their linear dimensions. (Author) [pt

  12. Derivation of the electric dipole--dipole interaction as an electric hyperfine interaction

    International Nuclear Information System (INIS)

    Parker, G.W.

    1986-01-01

    The electric dipole--dipole interaction is derived by assuming that the electron and proton in hydrogen have intrinsic electric dipole moments that interact to give an electric hyperfine interaction. The electric field at the proton due to the electron's presumed dipole moment then gives rise to a contact type term for l = 0 and the normal dipole--dipole term for lnot =0. When combined with our previous derivation of the magnetic hyperfine interaction [Am. J. Phys. 52, 36 (1984)], which used a similar approach, these derivations provide a unified treatment of the interaction of electric and magnetic dipoles. As an application of these results, the product of the electron's and proton's dipole moments is estimated to be less than 10 -29 e 2 cm 2

  13. Enhanced and tunable electric dipole-dipole interactions near a planar metal film

    Science.gov (United States)

    Zhou, Lei-Ming; Yao, Pei-Jun; Zhao, Nan; Sun, Fang-Wen

    2017-08-01

    We investigate the enhanced electric dipole-dipole interaction of surface plasmon polaritons (SPPs) supported by a planar metal film waveguide. By taking two nitrogen-vacancy (NV) center electric dipoles in diamond as an example, both the coupling strength and collective relaxation of two dipoles are studied with the numerical Green Function method. Compared to two-dipole coupling on a planar surface, metal film provides stronger and tunable coupling coefficients. Enhancement of the interaction between coupled NV center dipoles could have applications in both quantum information and energy transfer investigation. Our investigation provides systematic results for experimental applications based on a dipole-dipole interaction mediated with SPPs on a planar metal film.

  14. How to introduce the magnetic dipole moment

    International Nuclear Information System (INIS)

    Bezerra, M; Kort-Kamp, W J M; Cougo-Pinto, M V; Farina, C

    2012-01-01

    We show how the concept of the magnetic dipole moment can be introduced in the same way as the concept of the electric dipole moment in introductory courses on electromagnetism. Considering a localized steady current distribution, we make a Taylor expansion directly in the Biot-Savart law to obtain, explicitly, the dominant contribution of the magnetic field at distant points, identifying the magnetic dipole moment of the distribution. We also present a simple but general demonstration of the torque exerted by a uniform magnetic field on a current loop of general form, not necessarily planar. For pedagogical reasons we start by reviewing briefly the concept of the electric dipole moment. (paper)

  15. Dipoles on a Two-leg Ladder

    DEFF Research Database (Denmark)

    Gammelmark, Søren; Zinner, Nikolaj Thomas

    2013-01-01

    We study polar molecules with long-range dipole-dipole interactions confined to move on a two-leg ladder for different orientations of the molecular dipole moments with respect to the ladder. Matrix product states are employed to calculate the many-body ground state of the system as function...... that there is a critical angle at which ordering disappears. This angle is slightly larger than the angle at which the dipoles are non-interacting along a single leg. This behavior should be observable using current experimental techniques....

  16. Stellar oscillations in planet-hosting giant stars

    Energy Technology Data Exchange (ETDEWEB)

    Hatzes, Artie P; Zechmeister, Mathias [Thueringer Landessternwarte, Sternwarte 5, D-07778 (Germany)], E-mail: artie@tls-tautenburg.de

    2008-10-15

    Recently a number of giant extrasolar planets have been discovered around giant stars. These discoveries are important because many of these giant stars have intermediate masses in the range 1.2-3 Msun. Early-type main sequence stars of this mass range have been avoided by radial velocity planet search surveys due the difficulty of getting the requisite radial velocity precision needed for planet discoveries. Thus, giant stars can tell us about planet formation for stars more massive than the sun. However, the determination of stellar masses for giant stars is difficult due to the fact that evolutionary tracks for stars covering a wide range of masses converge to the same region of the H-R diagram. We report here on stellar oscillations in three planet-hosting giant stars: HD 13189, {beta} Gem, and {iota} Dra. Precise stellar radial velocity measurements for these stars show variations whose periods and amplitudes are consistent with solar-like p-mode oscillations. The implied stellar masses for these objects based on the characteristics of the stellar oscillations are consistent with the predictions of stellar isochrones. An investigation of stellar oscillations in planet hosting giant stars offers us the possibility of getting an independent determination of the stellar mass for these objects which is of crucial importance for extrasolar planet studies.

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

    International Nuclear Information System (INIS)

    Foglia, G.A.

    1991-01-01

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

  18. Testing of a Single 11 T $Nb_3Sn$ Dipole Coil Using a Dipole Mirror Structure

    Energy Technology Data Exchange (ETDEWEB)

    Zlobin, Alexander [Fermilab; Andreev, Nicolai [Fermilab; Barzi, Emanuela [Fermilab; Chlachidze, Guram [Fermilab; Kashikhin, Vadim [Fermilab; Nobrega, Alfred [Fermilab; Novitski, Igor [Fermilab; Turrioni, Daniele [Fermilab; Karppinen, Mikko [CERN; Smekens, David [CERN

    2014-07-01

    FNAL and CERN are developing an 11 T Nb3Sn dipole suitable for installation in the LHC. To optimize coil design parameters and fabrication process and study coil performance, a series of 1 m long dipole coils is being fabricated. One of the short coils has been tested using a dipole mirror structure. This paper describes the dipole mirror magnetic and mechanical designs, and reports coil parameters and test results.

  19. Solitary excitations in discrete two-dimensional nonlinear Schrodinger models with dispersive dipole-dipole interactions

    DEFF Research Database (Denmark)

    Christiansen, Peter Leth; Gaididei, Yuri Borisovich; Johansson, M.

    1998-01-01

    The dynamics of discrete two-dimensional nonlinear Schrodinger models with long-range dispersive interactions is investigated. In particular, we focus on the cases where the dispersion arises from a dipole-dipole interaction, assuming the dipole moments at each lattice site to be aligned either...

  20. Permanent Electric Dipole-Dipole Interactions in Lyotropic Polypeptide Liquid Crystals

    OpenAIRE

    MORI, Norio; Norio, MORI; Research Associate, Department of Industrial Chemistry

    1981-01-01

    The interaction energy between two adjacent α-helical molecules was calculated taking into account for permanent electric dipoles locating orl the helical core of a polymer mainchain in order to explain the cholesteric structure of lyotropic polypeptide liquid crystals. It was concluded that the dipole-dipole interactions were responsible for the formation of the cholesteric structure.

  1. Neutral dipole-dipole dimers: A new field in science

    Science.gov (United States)

    Kosower, Edward M.; Borz, Galina

    2018-03-01

    Dimer formation with dipole neutralization produces species such as low polarity water (LPW) compatible with hydrophobic surfaces (Phys. Chem. Chem. Phys. 2015, 17, 24895-24900) Dimerization and dipole neutralization occurs for N-methylacetamide on polyethylene, a behavior drastically different from its contortions in acetonitrile on AgBr:AgCl planar crystals (AgX) (ChemPhysChem 2014, 15, 3598-3607). The weak infrared absorption of the amide dimer on polyethylene is shown experimentally. Dimerization of palmitic acid is shown along with some of the many ramifications for intracellular systems. Polyoligomers of water are present on polyethylene surfaces. Some high resolution spectra of three of the polyoligomers of water are shown along with a mechanistic scheme for polyoligomer formation and dissolution. The structures of some of the oligomers are known from spectroscopic studies of water on AgX. The scope of the article begins with PE, generally accepted as hydrophobic. The IR of PE revealed not only that water was present but that it appeared in two forms, oligomers (O) and polyoligomers (PO). How did we recognize what they were? These species had been observed as especially strong "marker" peaks in the spectra1 of water placed on planar AgX, a platform developed by Katzir and his coworkers [6]. But there was a problem: the proximity to PE of oligomers with substantial (calculated) dipole moments and thus polarity, including cyclic hexamers of water (chair and boat forms), the cyclic pentamer, the books I and II, and the cyclic trimer [7a]. Another link was needed, a role perfectly fit by the already cited low polarity water (LPW). The choice was experimentally supported by the detection of low intensity absorption in the bending region.Some important generalities flow from these results. What other dimers might be present in the biological or chemical world? Palmitic acid dimer (PAD) would be a candidate for decreasing the polarity of the acid (PA). Another

  2. Spin and isospin modes

    International Nuclear Information System (INIS)

    Suzuki, T.; Sagawa, H.

    2000-01-01

    Complete text of publication follows. Spin and isospin modes in nuclei are investigated. We discuss some of the following topics. 1. Spin-dipole excitations in 12 C and 16 O are studied (1). Effects of tensor and spin-orbit interactions on the distribution of the strengths are investigated, and neutral current neutrino scattering cross sections in 16 O are obtained for heavy-flavor neutrinos from the supernovae. 2. Gamow-Teller (GT) and spin-dipole (SD) modes in 208 Bi are investigated. Quenching and fragmentation of the GT strength are discussed (2). SD excitations and electric dipole (E1) transitions between the GT and SD states are studied (3). Calculated E1 strengths are compared with the sum rule values obtained within the 1p-1h and 1p-1h + 2p-2h configuration spaces. 3. Coulomb displacement energy (CDE) of the IAS of 14 Be is calculated, and the effects of the halo on the CDE and the configuration of the halo state are investigated. 4. Spreading width of IAS and isospin dependence of the width are investigated (4). Our formula for the width explains very well the observed isospin dependence (5). (author)

  3. Local gyrokinetic study of electrostatic microinstabilities in dipole plasmas

    Science.gov (United States)

    Xie, Hua-sheng; Zhang, Yi; Huang, Zi-cong; Ou, Wei-ke; Li, Bo

    2017-12-01

    A linear gyrokinetic particle-in-cell scheme, which is valid for an arbitrary perpendicular wavelength k⊥ρi and includes the parallel dynamic along the field line, is developed to study the local electrostatic drift modes in point and ring dipole plasmas. We find that the most unstable mode in this system can be either the electron mode or the ion mode. The properties and relations of these modes are studied in detail as a function of k⊥ρi , the density gradient κn, the temperature gradient κT, electron to ion temperature ratio τ=Te/Ti , and mass ratio mi/me . For conventional weak gradient parameters, the mode is on the ground state (with eigenstate number l = 0) and especially k∥˜0 for small k⊥ρi . Thus, the bounce averaged dispersion relation is also derived for comparison. For strong gradient and large k⊥ρi , most interestingly, higher order eigenstate modes with even (e.g., l = 2, 4) or odd (e.g., l = 1) parity can be most unstable, which is not expected in the previous studies. High order eigenstate can also easily be most unstable at weak gradient when τ>10 . This work can be particularly important to understand the turbulent transport in laboratory and space magnetosphere.

  4. Fission decay properties of nuclear giant multipole resonances

    International Nuclear Information System (INIS)

    Dias, H.; Arruda Neto, J.D.T.; Hussein, M.S.; Carlson, B.V.

    1986-05-01

    The statistical fission decay properties of the giant dipole, quadrupole and monopole resonances in 236 U are investigated with the aid of the Hauser-Feshbach model. It is found, contrary to several recent claims, that the GQR fission decay probability is as large as that of the GDR, at energies higher than the fission barrier. At energies close to the f.b., the GQR fission probability is found to be appreciably larger than that of the GDR. The GMR fission probability follows closely that of the GQR. (Author) [pt

  5. The giant resonances in hot nuclei. Linear response calculations

    International Nuclear Information System (INIS)

    Braghin, F.L.; Vautherin, D.; Abada, A.

    1995-01-01

    The isovector response function of hot nuclear matter is calculated using various effective Skyrme interactions. For Skyrme forces with a small effective mass the strength distribution is found to be nearly independent of temperature, and shows little collective effects. In contrast effective forces with an effective mass close to unity produce at zero temperature sizeable collective effects which disappear at temperatures of a few MeV. The relevance of these results for the saturation of the multiplicity of photons emitted by the giant dipole resonance in hot nuclei observed in recent experiments beyond T = 3 MeV is discussed. (authors). 12 refs., 3 figs

  6. Schottky-contact plasmonic dipole rectenna concept for biosensing.

    Science.gov (United States)

    Alavirad, Mohammad; Mousavi, Saba Siadat; Roy, Langis; Berini, Pierre

    2013-02-25

    Nanoantennas are key optical components for several applications including photodetection and biosensing. Here we present an array of metal nano-dipoles supporting surface plasmon polaritons (SPPs) integrated into a silicon-based Schottky-contact photodetector. Incident photons coupled to the array excite SPPs on the Au nanowires of the antennas which decay by creating "hot" carriers in the metal. The hot carriers may then be injected over the potential barrier at the Au-Si interface resulting in a photocurrent. High responsivities of 100 mA/W and practical minimum detectable powers of -12 dBm should be achievable in the infra-red (1310 nm). The device was then investigated for use as a biosensor by computing its bulk and surface sensitivities. Sensitivities of ∼ 250 nm/RIU (bulk) and ∼ 8 nm/nm (surface) in water are predicted. We identify the mode propagating and resonating along the nanowires of the antennas, we apply a transmission line model to describe the performance of the antennas, and we extract two useful formulas to predict their bulk and surface sensitivities. We prove that the sensitivities of dipoles are much greater than those of similar monopoles and we show that this difference comes from the gap in dipole antennas where electric fields are strongly enhanced.

  7. Iron saturation control in RHIC dipole magnets

    International Nuclear Information System (INIS)

    Thompson, P.A.; Gupta, R.C.; Kahn, S.A.; Hahn, H.; Morgan, G.H.; Wanderer, P.J.; Willen, E.

    1991-01-01

    The Relativistic Heavy Ion Collider (RHIC) will require 360 dipoles of 80 mm bore. This paper discusses the field perturbations produced by the saturation of the yoke iron. Changes have been made to the yoke to reduce these perturbations, in particular, decapole -4 . Measurements and calculations for 6 series of dipole magnets are presented. 2 refs., 2 figs., 1 tab

  8. Microscopic evaluation of the nuclear dipole polarizability

    Energy Technology Data Exchange (ETDEWEB)

    Lipparini, E; Orlandini, G; Stringari, S; Traini, M [Trento Univ. (Italy). Dept. di Matematica e Fisica

    1977-12-01

    The dipole polarizability sum rule has been evaluated by means of a restricted Hartree-Fock approach. The method leads to a simple and analytical expression for the dipole polarizability. Explicit calculations have been performed in /sup 16/O and /sup 40/Ca with different types of interaction.

  9. Electric dipoles on the Bloch sphere

    OpenAIRE

    Vutha, Amar C.

    2014-01-01

    The time evolution of a two-level quantum mechanical system can be geometrically described using the Bloch sphere. By mapping the Bloch sphere evolution onto the dynamics of oscillating electric dipoles, we provide a physically intuitive link between classical electromagnetism and the electric dipole transitions of atomic & molecular physics.

  10. Electric dipoles on the Bloch sphere

    International Nuclear Information System (INIS)

    Vutha, Amar C

    2015-01-01

    The time evolution of a two-level quantum mechanical system can be geometrically described using the Bloch sphere. By mapping the Bloch sphere evolution onto the dynamics of oscillating electric dipoles, we provide a physically intuitive link between classical electromagnetism and the electric dipole transitions of atomic and molecular physics. (paper)

  11. Droplet-model electric dipole moments

    International Nuclear Information System (INIS)

    Myers, W.D.; Swiatecki, W.J.

    1991-01-01

    Denisov's recent criticism of the droplet-model formula for the dipole moment of a deformed nucleus as derived by Dorso et al., it shown to be invalid. This helps to clarify the relation of theory to the measured dipole moments, as discussed in the review article by Aberg et al. (orig.)

  12. Electrostatic-Dipole (ED) Fusion Confinement Studies

    Science.gov (United States)

    Miley, George H.; Shrestha, Prajakti J.; Yang, Yang; Thomas, Robert

    2004-11-01

    The Electrostatic-Dipole (ED) concept significantly differs from a "pure" dipole confinement device [1] in that the charged particles are preferentially confined to the high-pressure region interior of the dipole coil by the assistance of a surrounding spherical electrostatic grid. In present ED experiments, a current carrying coil is embedded inside the grid of an IEC such as to produce a magnetic dipole field. Charged particles are injected axisymmetrically from an ion gun (or duo-plasmatron) into the center of the ED confinement grid/dipole ring where they oscillate along the magnetic field lines and pass the peak field region at the center of the dipole region. As particles begin accelerating away from the center region towards the outer electrostatic grid region, they encounter a strong electrostatic potential (order of 10's of kilovolts) retarding force. The particles then decelerate, reverse direction and re-enter the dipole field region where again magnetic confinement dominates. This process continues, emulating a complex harmonic oscillator motion. The resulting pressure profile averaged over the field curvature offers good plasma stability in the ED configuration. The basic concept and results from preliminary experiments will be described. [1] M.E. Mauel, et al. "Dipole Equilibrium and Stability," 18th IAEA Conference of Plasma Phys. and Control. Nuclear Fusion, Varenna, Italy 2000, IAEA-F1-CN-70/TH

  13. Slice of LHC dipole wiring

    CERN Multimedia

    Dipole model slice made in 1994 by Ansaldo. The high magnetic fields needed for guiding particles around the Large Hadron Collider (LHC) ring are created by passing 12’500 amps of current through coils of superconducting wiring. At very low temperatures, superconductors have no electrical resistance and therefore no power loss. The LHC is the largest superconducting installation ever built. The magnetic field must also be extremely uniform. This means the current flowing in the coils has to be very precisely controlled. Indeed, nowhere before has such precision been achieved at such high currents. 50’000 tonnes of steel sheets are used to make the magnet yokes that keep the wiring firmly in place. The yokes constitute approximately 80% of the accelerator's weight and, placed side by side, stretch over 20 km!

  14. Top down electroweak dipole operators

    Science.gov (United States)

    Fuyuto, Kaori; Ramsey-Musolf, Michael

    2018-06-01

    We derive present constraints on, and prospective sensitivity to, the electric dipole moment (EDM) of the top quark (dt) implied by searches for the EDMs of the electron and nucleons. Above the electroweak scale v, the dt arises from two gauge invariant operators generated at a scale Λ ≫ v that also mix with the light fermion EDMs under renormalization group evolution at two-loop order. Bounds on the EDMs of first generation fermion systems thus imply bounds on |dt |. Working in the leading log-squared approximation, we find that the present upper bound on |dt | is 10-19 e cm for Λ = 1 TeV, except in regions of finely tuned cancellations that allow for |dt | to be up to fifty times larger. Future de and dn probes may yield an order of magnitude increase in dt sensitivity, while inclusion of a prospective proton EDM search may lead to an additional increase in reach.

  15. Charting the Giants

    Science.gov (United States)

    2004-06-01

    Largest Census Of X-Ray Galaxy Clusters Provides New Constraints on Dark Matter [1] Clusters of galaxies Clusters of galaxies are very large building blocks of the Universe. These gigantic structures contain hundreds to thousands of galaxies and, less visible but equally interesting, an additional amount of "dark matter" whose origin still defies the astronomers, with a total mass of thousands of millions of millions times the mass of our Sun. The comparatively nearby Coma cluster, for example, contains thousands of galaxies and measures more than 20 million light-years across. Another well-known example is the Virgo cluster at a distance of about 50 million light-years, and still stretching over an angle of more than 10 degrees in the sky! Clusters of galaxies form in the densest regions of the Universe. As such, they perfectly trace the backbone of the large-scale structures in the Universe, in the same way that lighthouses trace a coastline. Studies of clusters of galaxies therefore tell us about the structure of the enormous space in which we live. The REFLEX survey ESO PR Photo 18a/04 ESO PR Photo 18a/04 Galaxy Cluster RXCJ 1206.2-0848 (Visible and X-ray) [Preview - JPEG: 400 x 478 pix - 70k] [Normal - JPEG: 800 x 956 pix - 1.2Mk] Caption: PR Photo 18a shows the very massive distant cluster of galaxies RXCJ1206.2-0848, newly discovered during the REFLEX project, and located at a redshift of z = 0.44 [3]. The contours indicate the X-ray surface brightness distribution. Most of the yellowish galaxies are cluster members. A gravitationally lensed galaxy with a distorted, very elongated image is seen, just right of the centre. The image was obtained with the EFOSC multi-mode instrument on the ESO 3.6-m telescope at the La Silla Observatory (Chile). ESO PR Photo 18b/04 ESO PR Photo 18b/04 Galaxy cluster RXCJ1131.9-1955 [Preview - JPEG: 400 x 477 pix - 40k] [Normal - JPEG: 800 x 953 pix - 912k] [FullRes - JPEG: 2251 x 2681 pix - 7.7Mk] Caption: PR Photo 18b displays

  16. High-field dipoles for future accelerators

    International Nuclear Information System (INIS)

    Wipf, S.L.

    1984-09-01

    This report presents the concept for building superconducting accelerator dipoles with record high fields. Economic considerations favor the highest possible current density in the windings. Further discussion indicates that there is an optimal range of pinning strength for a superconducting material and that it is not likely for multifilamentary conductors to ever equal the potential performance of tape conductors. A dipole design with a tape-wound, inner high-field winding is suggested. Methods are detailed to avoid degradation caused by flux jumps and to overcome problems with the dipole ends. Concerns for force support structure and field precision are also addressed. An R and D program leading to a prototype 11-T dipole is outlined. Past and future importance of superconductivity to high-energy physics is evident from a short historical survey. Successful dipoles in the 10- to 20-T range will allow interesting options for upgrading present largest accelerators

  17. Giant Congenital Melanocytic Nevus

    DEFF Research Database (Denmark)

    Rasmussen, Bo Sonnich; Henriksen, Trine Foged; Kølle, Stig-Frederik Trojahn

    2015-01-01

    Giant congenital melanocytic nevi (GCMN) occur in 1:20,000 livebirths and are associated with increased risk of malignant transformation. The treatment of GCMN from 1981 to 2010 in a tertiary referral center was reviewed evaluating the modalities used, cosmetic results, associated complications...

  18. Waking the Sleeping Giant

    NARCIS (Netherlands)

    Ollenburger, Mary H.; Descheemaeker, Katrien; Crane, Todd A.; Sanogo, Ousmane M.; Giller, Ken E.

    2016-01-01

    The World Bank argued that West Africa's Guinea Savannah zone forms part of “Africa's Sleeping Giant,” where increases in agricultural production could be an engine of economic growth, through expansion of cultivated land in sparsely populated areas. The district of Bougouni, in southern Mali,

  19. from the Giant Panda

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-03

    Jun 3, 2009 ... 1College of Life Science, China West Normal University, 44# Yuying Road, 637002, Nanchong, China. 2Zhan Jiang educational ... in Escherichia coli and the RPS28 protein fusioned with the N-terminally GST -tagged protein gave rise ... long Conservation Center of the Giant Panda, Sichuan, China. The.

  20. Giant scrotal elephantiasis.

    Science.gov (United States)

    Kuepper, Daniel

    2005-02-01

    How much can a man carry? Penoscrotal elephantiasis is a debilitating syndrome. This is a case report of a patient with giant genital elephantiasis secondary to long-standing lymphogranuloma venereum infection in Ethiopia. Complete surgical resection of the pathologic tissue and penile reconstruction was undertaken with good cosmetic and functional results.

  1. Giant vesical calculus

    African Journals Online (AJOL)

    Giant vesical calculus. A case report. H. H. LAUBSCHER. Summary. An exceptional case of bladder stone is presented. The case is unusual as regards the size of the stone and the fact that the patient did··not seek medical assistance much earlier, as this was readily avail- able. Furthermore, recovery after removal of the.

  2. Juvenile giant fibroadenoma

    Directory of Open Access Journals (Sweden)

    Vipul Yagnik

    2011-07-01

    Full Text Available Fibroadenomas are benign solid tumor associated with aberration of normal lobular development. Juvenile giant fibroadenoma is usually single and >5 cm in size /or >500 gms in weight. Important differential diagnoses are: phyllodes tumor and juvenile gigantomastia. Simple excision is the treatment of choice.

  3. Giant abdominal cystic lymphangioma

    International Nuclear Information System (INIS)

    Vazquez, V.; Florencio, I.; Boluda, F.

    1996-01-01

    We present a case of giant abdominal cystic lymphangioma in a 10-year-old boy. Despite numerous consultations with physicians to identify the underlying problem, it had originally been attributed to ascites of unknown cause. We review the characteristics of this lesion and the diagnostic features that aid in differentiating it from ascites

  4. Giant peritoneal loose bodies

    African Journals Online (AJOL)

    2015-03-27

    Mar 27, 2015 ... not be familiar with the entity, can potentially be confused with malignant or parasitic lesions. Familiarity with their characteristic computed tomographic ... preventing unnecessary surgical intervention in an asymptomatic patient.3,4 It is important to differentiate giant peritoneal loose bodies from lesions such ...

  5. Electric dipole radiation at VLF in a uniform warm magneto-plasma.

    Science.gov (United States)

    Wang, T. N. C.; Bell, T. F.

    1972-01-01

    Use of a linear full electromagnetic wave theory to calculate the input impedance of an electric antenna embedded in a uniform, lossless, unbounded warm magnetoplasma, which is assumed to consist of warm electrons and cold ions. In calculating the dipole radiation resistance for the thermal modes and the thermally modified whistler mode the analysis includes the finite temperature only for the electrons. In deriving the formal solution of the warm plasma dipole input impedance a full-wave analysis is used and two antenna orientations are considered, parallel and perpendicular to the static magnetic field. A general dispersion equation governing the modes of propagation is derived and a detailed analysis is made of the propagation characteristics of these modes.

  6. Piezoelectric components wirelessly driven by dipole antenna-like electric field generator

    Energy Technology Data Exchange (ETDEWEB)

    Bhuyan, S., E-mail: elesatya@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore); Kumar, R.; Panda, S.K. [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore); Hu, J. [Lab of Precision Drive, Nanjing University of Aeronautics and Astronautics, Nanjing 210026 (China)

    2011-08-25

    Highlights: > Wireless energy transmission technique. > Dipole antenna-like electric field generator. > Piezoelecctric resonance. > Finite element analyses. > Simulations and experimental verifications. - Abstract: A new technique of transmitting electric energy wirelessly to piezoelectric components by using a dipole antenna-like electric field generator is explored. Two square size brass plate-shaped live and ground electrodes are used to form a dipole antenna-like electric field generator. When the dipole antenna-like electric field generator in electric resonance with an inductor, a maximum output power of 2.72 mW and an energy conversion efficiency of 0.0174% have been achieved wirelessly by the piezoelectric plate area of 40 mm{sup 2} operating in the thickness vibration mode, placed at the center 4 mm away from the antenna plane with an optimum electrical load of 1365 {Omega}, resonant frequency of 782 kHz, 1 cm electrodes separation, 2500 cm{sup 2} electrode area of dipole antenna-like structure, and input ac source power of 15.58 W applied to the series of dipole antenna-like structure and inductor. The theoretically calculated results have been validated by the experimental studies. It is seen that at the resonance frequency and optimum electrical load, the output power of the wirelessly driven piezoelectric component decreases with the size of piezoelectric component, distance of piezoelectric component from the electrode of antenna plane, but increases with the antenna electrode area.

  7. Electromagnetic drift modes in an inhomogeneous electron gas

    DEFF Research Database (Denmark)

    Shukla, P. K.; Pecseli, H. L.; Juul Rasmussen, Jens

    1986-01-01

    A pair of nonlinear equations is derived which describes the dynamics of the electromagnetic drift oscillations in a nonuniform magnetized electron gas. It is shown that the nonlinear electromagnetic drift modes can propagate in the form of dipole vortices...

  8. Constraints on exotic dipole-dipole couplings between electrons at the micron scale

    Science.gov (United States)

    Kotler, Shlomi; Ozeri, Roee; Jackson Kimball, Derek

    2015-05-01

    Until recently, the magnetic dipole-dipole coupling between electrons had not been directly observed experimentally. This is because at the atomic scale dipole-dipole coupling is dominated by the exchange interaction and at larger distances the dipole-dipole coupling is overwhelmed by ambient magnetic field noise. In spite of these challenges, the magnetic dipole-dipole interaction between two electron spins separated by 2.4 microns was recently measured using the valence electrons of trapped Strontium ions [S. Kotler, N. Akerman, N. Navon, Y. Glickman, and R. Ozeri, Nature 510, 376 (2014)]. We have used this measurement to directly constrain exotic dipole-dipole interactions between electrons at the micron scale. For light bosons (mass 0.1 eV), we find that coupling constants describing pseudoscalar and axial-vector mediated interactions must be | gPegPe/4 πℏc | <= 1 . 5 × 10-3 and | gAegAe/4 πℏc | <= 1 . 2 × 10-17 , respectively, at the 90% confidence level. These bounds significantly improve on previous constraints in this mass range: for example, the constraints on axial-vector interactions are six orders of magnitude stronger than electron-positron constraints based on positronium spectroscopy. Supported by the National Science Foundation, I-Core: the Israeli excellence center, and the European Research Council.

  9. SSC collider dipole magnet end mechanical design

    International Nuclear Information System (INIS)

    Delchamps, S.W.; Bossert, R.C.; Carson, J.; Ewald, K.; Fulton, H.; Kerby, J.; Koska, W.; Strait, J.; Wake, S.M.; Leung, K.K.

    1991-05-01

    This paper describes the mechanical design of the ends of Superconducting Super Collider dipole magnets to be constructed and tested at Fermilab. Coil end clamps, end yoke configuration, and end plate design are discussed. Loading of the end plate by axial Lorentz forces is discussed. Relevant data from 40 mm and 50 mm aperture model dipole magnets built and tested at Fermilab are presented. In particular, the apparent influence of end clamp design on the quench behavior of model SSC dipoles is described. 8 refs., 3 figs

  10. Is the 2MASS dipole convergent?

    OpenAIRE

    Chodorowski, Michał; Bilicki, Maciej; Mamon, Gary A.; Jarrett, Thomas

    2010-01-01

    We study the growth of the clustering dipole of galaxies from the Two Micron All Sky Survey (2MASS). We find that the dipole does not converge before the completeness limit of the 2MASS Extended Source Catalog, i.e. up to about 300 Mpc/h. We compare the observed growth of the dipole with the theoretically expected, conditional growth for the LambdaCDM power spectrum and cosmological parameters constrained by WMAP. The observed growth turns out to be within 1-sigma confidence level of the theo...

  11. Dipole moments of the rho meson

    International Nuclear Information System (INIS)

    Hecht, M.B.; McKellar, B.H.P.

    1997-04-01

    The electric and magnetic dipole moments (EDM) of the rho meson are calculated using the propagators and vertices derived from the quantum chromodynamics Dyson-Schwinger equations. Results obtained from using the Bethe-Salpeter amplitude studied by Chappell, Mitchell et. al., and Pichowsky and Lee, are compared. The rho meson EDM is generated through the inclusion of a quark electric dipole moment, which is left as a free variable. These results are compared to the perturbative results to obtain a measure of the effects of quark interactions and confinement. The two dipole moments are also calculated using the phenomenological MIT bag model to provide a further basis for comparison

  12. Giant cystic craniopharyngiomas

    International Nuclear Information System (INIS)

    Young, S.C.; Zimmerman, R.A.; Nowell, M.A.; Bilaniuk, L.T.; Hackney, D.B.; Grossman, R.I.; Goldberg, H.I.

    1987-01-01

    Three cases of giant cystic craniopharyngiomas with large areas of extension beyond the suprasellar area are presented. The magnetic resonance (MR) appearance in one case is described. These giant tumors had large, multilobulated cysts that comprised the bulk of the tumors. In one case, there was an unusual extension of the large tumor cyst into the lateral ventricle. In two cases, the tumors extended to the level of the foramen magnum. On CT, the cyst contents of these two tumors were hyperdense and became hypodense postoperatively. All three tumors harbored calcifications in the form of clumps in the suprasellar region and rim calcifications around the cysts. None of the tumors exhibited contrast enhancement. A literature review of the radiographic features of craniopharyngiomas is discussed. (orig.)

  13. Giant duodenal ulcers

    Institute of Scientific and Technical Information of China (English)

    Eric Benjamin Newton; Mark R Versland; Thomas E Sepe

    2008-01-01

    Giant duodenal ulcers (GDUs) are a subset of duodenal ulcers that have historically resulted in greater morbidity than usual duodenal ulcers. Until recently,few cases had been successfully treated with medical therapy. However, the widespread use of endoscopy,the introduction of H-2 receptor blockers and proton pump inhibitors, and the improvement in surgical techniques all have revolutionized the diagnosis,treatment and outcome of this condition. Nevertheless,GDUs are still associated with high rates of morbidity,mortality and complications. Thus, surgical evaluation of a patient with a GDU should remain an integral part of patient care. These giant variants, while usually benign, can frequently harbor malignancy. A careful review of the literature highlights the important differences when comparing GDUs to classical peptic ulcers and why they must be thought of differently than their more common counterpart.

  14. Multispin giant magnons

    International Nuclear Information System (INIS)

    Bobev, N. P.; Rashkov, R. C.

    2006-01-01

    We investigate giant magnons from classical rotating strings in two different backgrounds. First we generalize the solution of Hofman and Maldacena and investigate new magnon excitations of a spin chain which are dual to a string on RxS 5 with two nonvanishing angular momenta. Allowing string dynamics along the third angle in the five sphere, we find a dispersion relation that reproduces the Hofman and Maldacena one and the one found by Dorey for the two spin case. In the second part of the paper we generalize the two 'spin' giant magnon to the case of β-deformed AdS 5 xS 5 background. We find agreement between the dispersion relation of the rotating string and the proposed dispersion relation of the magnon bound state on the spin chain

  15. Isoscalar giant resonances in a relativistic model

    International Nuclear Information System (INIS)

    L'Huillier, M.; Nguyen Van Giai.

    1988-07-01

    Isoscalar giant resonances in finite nuclei are studied in a relativistic Random Phase Approximation (RRPA) approach. The model is self-consistent in the sense that one set of coupling constants generates the Dirac-Hartree single-particle spectrum and the residual particle-hole interaction. The RRPA is used to calculate response functions of multipolarity L = 0,2,3, and 4 in light and medium nuclei. It is found that monopole and quadrupole modes exhibit a collective character. The peak energies are overestimated, but not as much as one might think if the bulk properties (compression modulus, effective mass) were the only relevant quantities

  16. The neutron electric dipole moment

    International Nuclear Information System (INIS)

    He, X.G.; McKellar, B.H.J.; Pakvasa, S.

    1989-01-01

    A systematic study was made of the electric dipole moment (EDM) of neutron D n in various models of CP violation. It was found that in the standard KM model with 3 families the neutron EDM is in the range 1.4x10 -33 ≤ D n ≤ 1.6x10 -31 ecm; that the two Higgs doublet model has approximately the same value of D n as the standard model; that D n in the Weinberg model is predicted to satisfy D n > 10 -25 ecm; that in a class of left-right symmetric models D n is of the order of 10 -26-11 ecm; that in supersymmetric models D n is of the order 10 -22 φ ecm with φ being the possible phase difference of the phases of gluino mass and the gluino-quark-smark mixing matrix and that the strong CP parameter θ is found to be θ -9 , using the present experimental limit that D n -25 ecm with 90% confidence. 65 refs., 10 figs

  17. Superconducting Coil of Po Dipole

    CERN Multimedia

    1983-01-01

    The Po superconducting dipole was built as a prototype beam transport magnet for the SPS extracted proton beam P0. Its main features were: coil aperture 72 mm, length 5 m, room-temperature yoke, NbTi cable conductor impregnated with solder, nominal field 4.2 T at 4.7 K (87% of critical field). It reached its nominal field without any quench.After this successful test up to its nominal field of 4.2 T, the power was not raised to reach a quench. The magnet was not installed in a beam and had no other further use. Nevertheless its construction provided knowledges and experience which became useful in the design and construction of the LHC magnets. The photo shows a detail of the inner layer winding before superposing the outer layer to form the complete coil of a pole. Worth noticing is the interleaved glass-epoxy sheet (white) with grooved channels for the flow of cooling helium. See also 8211532X.

  18. Red giants seismology

    Science.gov (United States)

    Mosser, B.; Samadi, R.; Belkacem, K.

    2013-11-01

    The space-borne missions CoRoT and Kepler are indiscreet. With their asteroseismic programs, they tell us what is hidden deep inside the stars. Waves excited just below the stellar surface travel throughout the stellar interior and unveil many secrets: how old is the star, how big, how massive, how fast (or slow) its core is dancing. This paper intends to paparazze the red giants according to the seismic pictures we have from their interiors.

  19. Giant Otters in Peru

    OpenAIRE

    Schenk C.; Staib E.

    1992-01-01

    We are in the second year of fieldwork surveying for Giant Otters in the southeastern rainforest of Peru, in three areas with differing levels of legal protection. While there is some illegal hunting still happening outside the protected areas, the main threat to the otters is badly-conducted tourism. Well-organised tourism can be a promising argument for establishing protected areas like national parks.

  20. Intraoral giant condyloma acuminatum

    Directory of Open Access Journals (Sweden)

    Gupta R

    2001-09-01

    Full Text Available A case of intraoral giant condyloma acuminatum is reported in a 50- year- old Indian. He did not respond to topical application of podophyllin 20% but responded partially to electric cauterisation. Surgical excision was done to get rid of the warty growh completely. Since there were no skin or genital lesions and no history of marital or extramarital sexual contact the lesion was probably acquired from environmental sources. Nonsexual transmission should be considered especially when the lesions are extragenital.

  1. Giant prolactinomas in women

    DEFF Research Database (Denmark)

    Delgrange, Etienne; Raverot, Gerald; Bex, Marie

    2014-01-01

    OBJECTIVE: To characterise distinctive clinical features of giant prolactinomas in women. DESIGN: A multicentre, retrospective case series and literature review. METHODS: We collected data from 15 female patients with a pituitary tumour larger than 4 cm and prolactin levels above 1000 μg/l and id......OBJECTIVE: To characterise distinctive clinical features of giant prolactinomas in women. DESIGN: A multicentre, retrospective case series and literature review. METHODS: We collected data from 15 female patients with a pituitary tumour larger than 4 cm and prolactin levels above 1000 μg....../l and identified 19 similar cases from the literature; a gender-based comparison of the frequency and age distribution was obtained from a literature review. RESULTS: The initial PubMed search using the term 'giant prolactinomas' identified 125 patients (13 women) responding to the inclusion criteria. The female......:male ratio was 1:9. Another six female patients were found by extending the literature search, while our own series added 15 patients. The median age at diagnosis was 44 years in women compared with 35 years in men (Pwomen (n=34), we...

  2. Demonstration of Magnetic Dipole Resonances of Dielectric Nanospheres in the Visible Region

    DEFF Research Database (Denmark)

    Evlyukhin, A. B.; Novikov, S. M.; Zywietz, U.

    2012-01-01

    Strong resonant light scattering by individual spherical Si nanoparticles is experimentally demonstrated, revealing pronounced resonances associated with the excitation of magnetic and electric modes in these nanoparticles. It is shown that the low-frequency resonance corresponds to the magnetic...... dipole excitation. Due to high permittivity, the magnetic dipole resonance is observed in the visible spectral range for Si nanoparticles with diameters of similar to 200 nm, thereby opening a way to the realization of isotropic optical metamaterials with strong magnetic responses in the visible region....

  3. Observation of dipole bands in 144Sm

    International Nuclear Information System (INIS)

    Raut, R.; Ganguly, S.; Kshetri, R.; Banerjee, P.; Bhattacharya, S.; Dasmahapatra, B.; Mukherjee, A.; Sahasarkar, M.; Goswami, A.; Basu, S.K.; Bhattacharjee, T.; Mukherjee, G.; Chakraborty, A.; Ghughre, S.S.; Krishichayan; Mukhopadhyay, S.; Gangopadhyay, G.; Singh, A.K.

    2007-01-01

    The nucleus 144 Sm (Z=62, N=82), with its proximity to the shell closure and possibilities of particles and holes occupying high j orbitals, following appropriate excitations, is a suitable system for observation of dipole (MR) bands

  4. Plasmonic functionalities based on detuned electrical dipoles

    DEFF Research Database (Denmark)

    Pors, Anders Lambertus; Nielsen, Michael Grøndahl; Bozhevolnyi, Sergey I.

    2013-01-01

    We introduce and demonstrate the concept of detuned electrical dipoles (DED) that originates from the plasmonic realization of the dressed-state picture of electromagnetically induced transparency in atomic physics. Numerically and experimentally analyzing DED metamaterials consisting of unit cells...

  5. Dislocation dipole annihilation in diamond and silicon

    Energy Technology Data Exchange (ETDEWEB)

    Rabier, J; Pizzagalli, L, E-mail: jacques.rabier@univ-poitiers.fr [Institut PPRIMME, Departement de Physique et Mecanique des Materiaux - UPR 3346 CNRS, Universite de Poitiers, ENSMA - SP2MI, BP 30179, F-86962 Chasseneuil Futuroscope Cedex (France)

    2011-02-01

    The mechanism of dislocation dipole annihilation has been investigated in C and Si using atomistic calculations with the aim of studying their annihilation by-products. It is shown, in C as well as in Si, that dipole annihilation yields debris that can be depicted as a cluster of vacancies, or alternately by two internal free surfaces. These defects have no strain field and can hardly be seen using usual TEM techniques. This suggests that the brown colouration of diamond could be due to microstructures resulting from deformation mechanisms associated with dipole formation and their annihilation rather than to a climb mechanism and vacancy aggregation. In silicon where a number of dipoles have been evidenced by TEM when dislocation trails are found, such debris could be the missing link responsible for the observation of strong chemical reactivity and electrical activity in the wake of moving dislocations.

  6. A sum rule calculation of the neutron electric dipole moment from a quark chromoelectric dipole coupling

    International Nuclear Information System (INIS)

    Kogan, I.I.; Wyler, D.

    1992-01-01

    The neutron electric dipole moment (NEDM) from a quark chromoelectric dipole moment is calculated using a QCD sumrule approach. We demonstrate that leading contributions to the NEDM come from induced condensates (quark and quark-gluon condensate magnetic susceptibilities) which are also determined. Other possible contributions to the NEDM such as a quark electric dipole moment or a triple gluon operator are briefly discussed. (orig.)

  7. Noncommutative QED and anomalous dipole moments

    International Nuclear Information System (INIS)

    Riad, I.F.; Sheikh-Jabbari, M.M.

    2000-09-01

    We study QED on noncommutative spaces, NCQED. In particular we present the detailed calculation for the noncommutative electron-photon vertex and show that the Ward identity is satisfied. We discuss that in the noncommutative case moving electron will show electric dipole effects. In addition, we work out the electric and magnetic dipole moments up to one loop level. For the magnetic moment we show that noncommutative electron has an intrinsic (spin independent) magnetic moment. (author)

  8. Colour dipoles and virtual Compton scattering

    International Nuclear Information System (INIS)

    McDermott, M.

    2002-01-01

    An analysis of Deeply Virtual Compton Scattering (DVCS) is made within the colour dipole model. We compare and contrast two models for the dipole cross-section which have been successful in describing structure function data. Both models agree with the available cross section data on DVCS from HERA. We give predictions for various azimuthal angle asymmetries in HERA kinematics and for the DVCS cross section in the THERA region. (orig.)

  9. Electric Dipole Echoes in Rydberg Atoms

    International Nuclear Information System (INIS)

    Yoshida, S.; Reinhold, C. O.; Burgdoerfer, J.; Zhao, W.; Mestayer, J. J.; Lancaster, J. C.; Dunning, F. B.

    2007-01-01

    We report the first observation of echoes in the electric dipole moment of an ensemble of Rydberg atoms precessing in an external electric field F. Rapid reversal of the field direction is shown to play a role similar to that of a π pulse in NMR in rephasing a dephased ensemble of electric dipoles resulting in the buildup of an echo. The mechanisms responsible for this are discussed with the aid of classical trajectory Monte Carlo simulations

  10. Magneto-Electric Dipole Antenna Arrays

    OpenAIRE

    Gupta, Shulabh; Jiang, Li Jun; Caloz, Christophe

    2014-01-01

    A planar magneto-electric (ME) dipole antenna array is proposed and demonstrated by both full-wave analysis and experiments. The proposed structure leverages the infinite wavelength propagation characteristic of composite right/left-handed (CRLH) transmission lines to form high-gain magnetic radiators combined with radial conventional electric radiators, where the overall structure is excited by a single differential feed. The traveling-wave type nature of the proposed ME-dipole antenna enabl...

  11. High field dipole magnet design concepts

    International Nuclear Information System (INIS)

    Nicol, T.H.

    1988-12-01

    High field dipole magnets will play a crucial role in the development of future accelerators whether at Fermilab or elsewhere. This paper presents conceptual designs for two such dipoles; 6.6 and 8.8 Tesla, with special focus on their suitability for upgrades to the Fermilab Tevatron. Descriptions and cross-sectional views will be presented as will preliminary estimates of heat loads and costs. 3 refs., 2 figs., 2 tabs

  12. Surface effects on the red giant branch

    Science.gov (United States)

    Ball, W. H.; Themeßl, N.; Hekker, S.

    2018-05-01

    Individual mode frequencies have been detected in thousands of individual solar-like oscillators on the red giant branch (RGB). Fitting stellar models to these mode frequencies, however, is more difficult than in main-sequence stars. This is partly because of the uncertain magnitude of the surface effect: the systematic difference between observed and modelled frequencies caused by poor modelling of the near-surface layers. We aim to study the magnitude of the surface effect in RGB stars. Surface effect corrections used for main-sequence targets are potentially large enough to put the non-radial mixed modes in RGB stars out of order, which is unphysical. Unless this can be circumvented, model-fitting of evolved RGB stars is restricted to the radial modes, which reduces the number of available modes. Here, we present a method to suppress gravity modes (g-modes) in the cores of our stellar models, so that they have only pure pressure modes (p-modes). We show that the method gives unbiased results and apply it to three RGB solar-like oscillators in double-lined eclipsing binaries: KIC 8410637, KIC 9540226 and KIC 5640750. In all three stars, the surface effect decreases the model frequencies consistently by about 0.1-0.3 μHz at the frequency of maximum oscillation power νmax, which agrees with existing predictions from three-dimensional radiation hydrodynamics simulations. Though our method in essence discards information about the stellar cores, it provides a useful step forward in understanding the surface effect in RGB stars.

  13. Probing the Deep End of the Milky Way with New Oscillating Kepler Giants

    Science.gov (United States)

    Mathur, Savita; García, Rafael A.; Huber, Daniel; Regulo, Clara; Stello, Dennis; Beck, Paul G.; Houmani, Kenza; Salabert, David

    2017-10-01

    The Kepler mission has been a success in both exoplanet search and stellar physics studies. Red giants have actually been quite a highlight in the Kepler scene. The Kepler long and almost continuous four-year observations allowed us to detect oscillations in more than 15,000 red giants targeted by the mission. However by looking at the power spectra of 45,000 stars classified as dwarfs according to the Q1-16 Kepler star properties catalog, we detected red-giant like oscillations in 850 stars. Even though this is a small addition to the known red-giant sample, these misclassified stars represent a goldmine for galactic archeology studies. Indeed they happen to be fainter (down to Kp 16) and more distant (d>10kPc) than the known red giants, opening the possibility to probe unknown regions of our Galaxy. The faintness of these red giants with detected oscillations is very promising for detecting acoustic modes in red giants observed with K2 and TESS. In this talk, I will present this new sample of red giants with their revised stellar parameters derived from asteroseismology. Then I will discuss about the distribution of their masses, distances, and evolutionary states compared to the previously known sample of red giants.

  14. Dipole and quadrupole magnetic resonances in nuclei of Ni isotopes

    International Nuclear Information System (INIS)

    Goncharova, N.G.; Mishchenko, G.M.; Ehramzhyan, R.A.

    1982-01-01

    Basing on a microscopic approach to the nuclear shell model, magnetic resonances following the electron excitation of the 58 Ni and 60 Ni nuclei are considered. 0h/2π#betta# and 2h/2π#betta#-transitions are taken into accoun for the M1-excitations. For the M2-states, transitions to the next shell are considered only. For the magnetic excitations the form factors and electron-excitation cross sections are calculated, and the effect of the lower 2 1+ , 2 2+ , 3 - , 4 + phonon excitations on the position and structure of the M1- and M2-resonances is traced. +he energies and mean equilibrium deformations are presented for the phonons taken into account. The structure and position of the main magnetic resonance maxima, in difference with the giant dipole resonance in photoabsorption, have proven to be weakly dependent on the isotope choice. For the M1-resonance this effect is related with the fact that the lower excitation states, located in the energy range E 60 Ni and 58 Ni, respectively. A strongly collectivized state, acquiring a notable strength of the M-1 transitions, is located at approximately 32 MeV. The form factor for this level attains the maximum at q=160-190 MeV/c

  15. Electron inelastic scattering by compound nuclei and giant multipole resonances

    International Nuclear Information System (INIS)

    Dzhavadov, A.V.; Mukhtarov, A.I.; Mirabutalybov, M.M.

    1980-01-01

    Multipole giant resonances in heavy nuclei have been investigated with the application of the Danos-Greiner dynamic collective theory to the Tassi model. The monopole giant resonance has been studied in 158 Gd, 166 Er, 184 W, 232 Th and 238 V nuclei at the incident electron energy E=200 MeV. Dependences of the form factor square of electron scattering by a 166 Er nucleus on the scattering angle obtained in the distorted-wave high-energy approximation (DWHEA) are presented. Giant dipole and quadrupole resonances in 60 Ni and 90 Zr nuclei have been studied. A comparison has been made of theoretical results obtained in the DWHEA for the dependence of the form factor square on the effective momentum transfer with the experimental data. The analysis of the obtained results led to the following conclusions. To draw a conclusion about the validity of one or another nuclear model and methods for calculating form factors, it is necessary to investigate, both theoretically and experimentally, electron scattering at great angles (THETA>=70 deg). To obtain a good agreement it is necessary to take account of the actual proton and neutron distributions in the ground state and their dynamic properties in an excited state [ru

  16. Giant Ulcerative Dermatofibroma

    Directory of Open Access Journals (Sweden)

    Turgut Karlidag

    2013-01-01

    Full Text Available Dermatofibroma is a slowly growing common benign cutaneous tumor characterized by hard papules and nodules. The rarely seen erosions and ulcerations may cause difficulties in the diagnosis. Dermatofibrosarcoma protuberans, which is clinically and histopathologically of malignant character, displays difficulties in the diagnosis since it has similarities with basal cell carcinoma, epidermoid carcinoma, and sarcomas. Head and neck involvement is very rare. In this study, a giant dermatofibroma case, which is histopathologically, ulcerative dermatofibroma, the biggest lesion of the head and neck region and seen rarely in the literature that has characteristics similar to dermatofibrosarcoma protuberans, has been presented.

  17. GIANT PROSTHETIC VALVE THROMBUS

    Directory of Open Access Journals (Sweden)

    Prashanth Kumar

    2015-04-01

    Full Text Available Mechanical prosthetic valves are predisposed to bleeding, thrombosis & thromboembolic complications. Overall incidence of thromboembolic complications is 1% per year who are on oral anticoagulants, whereas bleeding complications incidence is 0.5% to 6.6% per year. 1, 2 Minimization of Scylla of thromboembolic & Charybdis of bleeding complication needs a balancing act of optimal antithrombotic therapy. We are reporting a case of middle aged male patient with prosthetic mitral valve presenting in heart failure. Patient had discontinued anticoagulants, as he had subdural hematoma in the past. He presented to our institute with a giant prosthetic valve thrombus.

  18. A Giant Urethral Calculus.

    Science.gov (United States)

    Sigdel, G; Agarwal, A; Keshaw, B W

    2014-01-01

    Urethral calculi are rare forms of urolithiasis. Majority of the calculi are migratory from urinary bladder or upper urinary tract. Primary urethral calculi usually occur in presence of urethral stricture or diverticulum. In this article we report a case of a giant posterior urethral calculus measuring 7x3x2 cm in a 47 years old male. Patient presented with acute retention of urine which was preceded by burning micturition and dribbling of urine for one week. The calculus was pushed in to the bladder through the cystoscope and was removed by suprapubic cystolithotomy.

  19. Giant paraganglioma in

    Directory of Open Access Journals (Sweden)

    Alka Gupta

    2017-07-01

    Full Text Available Paraganglioma is a rare neuroendocrine catecholamine producing tumour in childhood which arises outside the adrenal medulla. We present a 12 year old girl with giant paraganglioma with severe hypertension and end organ damage. Diagnosis was confirmed with 24 h urinary Vanillymandelic Acid (VMA and CT scan. Preoperative blood pressure was controlled with intravenous nitroprusside, and oral prazosin, amlodepine, labetalol and metoprolol. General anaesthesia with epidural analgesia was given. Intra operative blood pressure rise was managed with infusion of nitriglycerine (NTG, esmolol, nitroprusside and propofol.

  20. GIANT INTRACANALICULAR FIBROADENOMA

    Science.gov (United States)

    Smith, Clyn; Parsons, Robert J.; Bogart, William M.

    1951-01-01

    Five cases of giant intracanalicular fibroadenoma (“cystosarcoma phylloides”) were observed at one hospital in a period of three years. In a search of the literature, additional reports of breast tumors of this kind, not included in previous reviews, were noted. As there is record of 229 cases, it would appear that this rapidly growing benign tumor should be kept in mind in the diagnosis of masses in the breast. If removal is incomplete, there may be recurrence. Simple mastectomy is the treatment of choice. Radical mastectomy should be avoided. ImagesFigure 1Figure 2.Figure 3Figure 4Figure 5 PMID:14848732

  1. Giant monopole resonance in transitional and deformed nuclei

    International Nuclear Information System (INIS)

    Garg, U.; Bogucki, P.; Bronson, J.D.; Lui, Y.; Youngblood, D.H.

    1984-01-01

    Small-angle inelastic α-scattering measurements have been made at E/sub α/ = 129 MeV on /sup 144,148/Sm and /sup 142,146,150/Nd to investigate the giant monopole resonance in transitional and deformed nuclei. The experimental data reveal a mixing of L = 0 and L = 2 modes in 148 Sm resulting in almost identical angular distributions for the two components of the giant resonance peaks in the angular range 2 0 --6 0 . A ''splitting'' of the giant monopole resonance is observed in 150 Nd; the extent of this splitting is smaller than that reported for 154 Sm. Comparison is made with the predictions of various theoretical models

  2. Dynamic dipole-dipole interactions between excitons in quantum dots of different sizes

    DEFF Research Database (Denmark)

    Matsueda, Hideaki; Leosson, Kristjan; Xu, Zhangcheng

    2004-01-01

    A model of the resonance dynamic dipole-dipole interaction between excitons confined in quantum dots (QDs) of different sizes at close enough distance is given in terms of parity inheritance and exchange of virtual photons. Microphotoluminescence spectra of GaAs-AlGaAs coupled QDs are proposed to...

  3. Dynamic Dipole-Dipole Interactions between Excitons in Quantum Dots of Different Sizes

    DEFF Research Database (Denmark)

    Matsueda, Hideaki; Leosson, Kristjan; Xu, Zhangcheng

    2005-01-01

    Micro-photoluminescence spectra of GaAs/AlGaAs coupled quantum dots (QDs) are given, and proposed to be analyzed by our resonance dynamic dipole-dipole interaction (RDDDI) model, based on parity inheritance and exchange of virtual photons among QDs of different sizes....

  4. Inhibition of two-photon absorption due to dipole-dipole interaction in nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Mahi R. [Department of Physics and Astronomy, University of Western Ontario, London, N6A 3K7 (Canada)], E-mail: msingh@uwo.ca

    2008-07-21

    We have investigated the inhibition of two-photon absorption in photonic crystals doped with an ensemble of four-level nanoparticles. The particles are interacting with one another by the dipole-dipole interaction. Dipoles in nanoparticles are induced by a selected transition. Numerical simulations have been performed for an isotropic photonic crystal. Interesting phenomena have been predicted such as the inhibition of the two-photon absorption due to the dipole-dipole interaction. It has also been found that the inhibition effect can be switched on and off by tuning a decay resonance energy within the energy band of the crystal. A theory of dressed states has been used to explain the results.

  5. LHC dipoles: the countdown has begun

    CERN Document Server

    Patrice Loiez

    2002-01-01

    At the entrance to the fourth floor corridor of the LHC-MMS (Main Magnets and Superconductors) Group in building 30, the Director-General has unveiled an electronic information panel indicating the number of LHC dipoles still to be delivered and the days remaining to the deadline (30 June 2006). The panel was the idea of Lucio Rossi, leader of the MMS Group, which is responsible for the construction of the dipole magnets. The unveiling ceremony took place on the morning of Friday 11 October 2002, at the end of a drink held to celebrate with MMS group and the LHC top management the exceptional performance of the latest dipoles, built by the French consortium Alstom-Jeumont. They are the first dipoles to achieve a magnetic field of 9 tesla in one go without quenching, thus exceeding the nominal operating field of 8.3 tesla. The challenge is now to increase the production rate from 2 to 35 dipoles per month by 2004 in order to meet the deadline, while maintaining this quality. Photo 01: The Director-General Luci...

  6. Allometry indicates giant eyes of giant squid are not exceptional.

    Science.gov (United States)

    Schmitz, Lars; Motani, Ryosuke; Oufiero, Christopher E; Martin, Christopher H; McGee, Matthew D; Gamarra, Ashlee R; Lee, Johanna J; Wainwright, Peter C

    2013-02-18

    The eyes of giant and colossal squid are among the largest eyes in the history of life. It was recently proposed that sperm whale predation is the main driver of eye size evolution in giant squid, on the basis of an optical model that suggested optimal performance in detecting large luminous visual targets such as whales in the deep sea. However, it is poorly understood how the eye size of giant and colossal squid compares to that of other aquatic organisms when scaling effects are considered. We performed a large-scale comparative study that included 87 squid species and 237 species of acanthomorph fish. While squid have larger eyes than most acanthomorphs, a comparison of relative eye size among squid suggests that giant and colossal squid do not have unusually large eyes. After revising constants used in a previous model we found that large eyes perform equally well in detecting point targets and large luminous targets in the deep sea. The eyes of giant and colossal squid do not appear exceptionally large when allometric effects are considered. It is probable that the giant eyes of giant squid result from a phylogenetically conserved developmental pattern manifested in very large animals. Whatever the cause of large eyes, they appear to have several advantages for vision in the reduced light of the deep mesopelagic zone.

  7. Magnetic dipole excitations of the 163Dy nucleus

    Science.gov (United States)

    Zenginerler, Zemine; Tabar, Emre; Yakut, Hakan; Kuliev, Ali Akbar; Guliyev, Ekber

    2014-03-01

    In this study some properties of the magnetic dipole excitations of the deformed odd mass 163Dy nucleus were studied by using Quasiparticle-phonon nuclear model (QPNM). The several of the ground-state and low-lying magnetic dipole (M1) mode characteristics were calculated for deformed odd-mass nuclei using a separable Hamiltonian within the QPNM. The M1 excited states, reduced transition probabilities B(M1), the ground-state magnetic properties such as magnetic moment (μ), intrinsic magnetic moment (gK) , effective spin factor (gseff.) are the fundamental characteristics of the odd-mass nucleus and provide key information to understand nuclear structure. The theoretical results were compared with the available experimental data and other theoretical approaches. Calculations show that the spin-spin interaction in this isotopes leads to polarization effect influencing the magnetic moments. Furthermore we found a strong fragmentation of the M1 strength in 163Dy nucleus which was in qualitative agreement with the experimental data. Sakarya University, Project Number: 2012-50-02-007 and Z.Zenginerler acknowledge to TUBITAK-TURKEY 2013, fellowship No: 2219.

  8. Perturbative odderon in the dipole model

    International Nuclear Information System (INIS)

    Kovchegov, Yuri V.; Szymanowski, Lech; Wallon, Samuel

    2004-01-01

    We show that, in the framework of Mueller's dipole model, the perturbative QCD odderon is described by the dipole model equivalent of the BFKL equation with a C-odd initial condition. The eigenfunctions and eigenvalues of the odderon solution are the same as for the dipole BFKL equation and are given by the functions E n,ν and χ(n,ν) correspondingly, where the C-odd initial condition allows only for odd values of n. The leading high-energy odderon intercept is given by α odd -1=((2α s N c )/(π))χ(n=1,ν=0)=0 in agreement with the solution found by Bartels, Lipatov and Vacca. We proceed by writing down an evolution equation for the odderon including the effects of parton saturation. We argue that saturation makes the odderon solution a decreasing function of energy

  9. Installation Strategy for the LHC Main Dipoles

    CERN Multimedia

    Fartoukh, Stephane David

    2004-01-01

    All positions in the LHC machine are not equivalent in terms of beam requirements on the geometry and the field quality of the main dipoles. In the presence of slightly or strongly out-of tolerance magnets, a well-defined installation strategy will therefore contribute to preserve or even optimize the performance of the machine. Based on the present status of the production, we have anticipated a list of potential issues (geometry, transfer function, field direction and random b3) which, combined by order of priority, have been taken into account to define a simple but efficient installation algorithm for the LHC main dipoles. Its output is a prescription for installing the available dipoles in sequence while reducing to an absolute minimum the number of holes required by geometry or FQ issues.

  10. Transportation studies: 40-MM collider dipole magnets

    International Nuclear Information System (INIS)

    Daly, E.

    1992-01-01

    Several fully functional 40-mm Collider Dipole Magnets (CDM) were instrumented with accelerometers to monitor shock and vibration loads during transport. The magnets were measured with optical tooling telescopes before and after transport. Changes in mechanical alignment due to shipping and handling were determined. The mechanical stability of the cryogen lines were checked using the same method. Field quality and dipole angle were measured warm before and after transport to determine changes in these parameters. Power spectra were calculated for accelerometers located on the cold mass, vacuum vessel, and trailer bed. Where available, plots of field quality and dipole roll both before and after were created. Shipping loads measured were largest in the vertical direction, where most of the structural deformation of the magnet was evident. It was not clear that magnetic performance was affected by the shipping and handling environment

  11. Perturbative odderon in the dipole model

    Energy Technology Data Exchange (ETDEWEB)

    Kovchegov, Yuri V.; Szymanowski, Lech; Wallon, Samuel

    2004-04-29

    We show that, in the framework of Mueller's dipole model, the perturbative QCD odderon is described by the dipole model equivalent of the BFKL equation with a C-odd initial condition. The eigenfunctions and eigenvalues of the odderon solution are the same as for the dipole BFKL equation and are given by the functions E{sup n,{nu}} and {chi}(n,{nu}) correspondingly, where the C-odd initial condition allows only for odd values of n. The leading high-energy odderon intercept is given by {alpha}{sub odd}-1=((2{alpha}{sub s}N{sub c})/({pi})){chi}(n=1,{nu}=0)=0 in agreement with the solution found by Bartels, Lipatov and Vacca. We proceed by writing down an evolution equation for the odderon including the effects of parton saturation. We argue that saturation makes the odderon solution a decreasing function of energy.

  12. Neutron Electric Dipole Moment from colored scalars⋆

    Directory of Open Access Journals (Sweden)

    Fajfer Svjetlana

    2014-01-01

    Full Text Available We present new contributions to the neutron electric dipole moment induced by a color octet, weak doublet scalar, accommodated within a modified Minimal Flavor Violating framework. These flavor non-diagonal couplings of the color octet scalar might account for an assymmetry of order 3 × 10−3 for aCP(D0 → K−K+ − aCP(D0 → π+π− at tree level. The same couplings constrained by this assymmetry also induce two-loop contributions to the neutron electric dipole moment. We find that the direct CP violating asymmetry in neutral D-meson decays is more constraining on the allowed parameter space than the current experimental bound on neutron electric dipole moment.

  13. Dipole strength distributions from HIGS Experiments

    Science.gov (United States)

    Werner, V.; Cooper, N.; Goddard, P. M.; Humby, P.; Ilieva, R. S.; Rusev, G.; Beller, J.; Bernards, C.; Crider, B. P.; Isaak, J.; Kelley, J. H.; Kwan, E.; Löher, B.; Peters, E. E.; Pietralla, N.; Romig, C.; Savran, D.; Scheck, M.; Tonchev, A. P.; Tornow, W.; Yates, S. W.; Zweidinger, M.

    2015-05-01

    A series of photon scattering experiments has been performed on the double-beta decay partners 76Ge and 76Se, in order to investigate their dipole response up to the neutron separation threshold. Gamma-ray beams from bremsstrahlung at the S-DALINAC and from Compton-backscattering at HIGS have been used to measure absolute cross sections and parities of dipole excited states, respectively. The HIGS data allows for indirect measurement of averaged branching ratios, which leads to significant corrections in the observed excitation cross sections. Results are compared to statistical calculations, to test photon strength functions and the Axel-Brink hypothesis

  14. Dipole vortices in the Great Australian Bight

    DEFF Research Database (Denmark)

    Cresswell, George R.; Lund-Hansen, Lars C.; Nielsen, Morten Holtegaard

    2015-01-01

    Shipboard measurements from late 2006 made by the Danish Galathea 3 Expedition and satellite sea surface temperature images revealed a chain of cool and warm mushroom' dipole vortices that mixed warm, salty, oxygen-poor waters on and near the continental shelf of the Great Australian Bight (GAB...... denser than the cooler offshore waters. The field of dipoles evolved and distorted, but appeared to drift westwards at 5km day-1 over two weeks, and one new mushroom carried GAB water southwards at 7km day(-1). Other features encountered between Cape Leeuwin and Tasmania included the Leeuwin Current...

  15. On the dipole approximation with error estimates

    Science.gov (United States)

    Boßmann, Lea; Grummt, Robert; Kolb, Martin

    2018-01-01

    The dipole approximation is employed to describe interactions between atoms and radiation. It essentially consists of neglecting the spatial variation of the external field over the atom. Heuristically, this is justified by arguing that the wavelength is considerably larger than the atomic length scale, which holds under usual experimental conditions. We prove the dipole approximation in the limit of infinite wavelengths compared to the atomic length scale and estimate the rate of convergence. Our results include N-body Coulomb potentials and experimentally relevant electromagnetic fields such as plane waves and laser pulses.

  16. Dipole strength distributions from HIGS Experiments

    Directory of Open Access Journals (Sweden)

    Werner V.

    2015-01-01

    76Ge and 76Se, in order to investigate their dipole response up to the neutron separation threshold. Gamma-ray beams from bremsstrahlung at the S-DALINAC and from Compton-backscattering at HIGS have been used to measure absolute cross sections and parities of dipole excited states, respectively. The HIGS data allows for indirect measurement of averaged branching ratios, which leads to significant corrections in the observed excitation cross sections. Results are compared to statistical calculations, to test photon strength functions and the Axel-Brink hypothesis

  17. Asymmetry of neoclassical transport by dipole electric field

    International Nuclear Information System (INIS)

    Wang Zhongtian; Wang Long

    2004-01-01

    Effects of dipole electric fields on neoclassical transport are studied. Large asymmetry in transport is created. The dipole fields, which are in a negative R-direction, reduce the ion drift, increase electron drift, and change the steps of excursion due to collisions. It is found that different levels of dipole field intensities have different types of transport. For the lowest level of the dipole field, the transport returns to the neoclassical one. For the highest level of the dipole field, the transport is turned to be the turbulence transport similar to the pseudo-classical transport. Experimental data may be corresponded to a large level of the dipole field intensity. (authors)

  18. Multiple transparency windows and Fano interferences induced by dipole-dipole couplings

    Science.gov (United States)

    Diniz, E. C.; Borges, H. S.; Villas-Boas, C. J.

    2018-04-01

    We investigate the optical properties of a two-level system (TLS) coupled to a one-dimensional array of N other TLSs with dipole-dipole coupling between the first neighbors. The first TLS is probed by a weak field, and we assume that it has a decay rate much greater than the decay rates of the other TLSs. For N =1 and in the limit of a Rabi frequency of a probe field much smaller than the dipole-dipole coupling, the optical response of the first TLS, i.e., its absorption and dispersion, is equivalent to that of a three-level atomic system in the configuration which allows one to observe the electromagnetically induced transparency (EIT) phenomenon. Thus, here we investigate an induced transparency phenomenon where the dipole-dipole coupling plays the same role as the control field in EIT in three-level atoms. We describe this physical phenomenon, named a dipole-induced transparency (DIT), and investigate how it scales with the number of coupled TLSs. In particular, we have shown that the number of TLSs coupled to the main TLS is exactly equal to the number of transparency windows. The ideas presented here are very general and can be implemented in different physical systems, such as an array of superconducting qubits, or an array of quantum dots, spin chains, optical lattices, etc.

  19. Toward verification of electroweak baryogenesis by electric dipole moments

    International Nuclear Information System (INIS)

    Fuyuto, Kaori; Hisano, Junji; Senaha, Eibun

    2016-01-01

    We study general aspects of the CP-violating effects on the baryon asymmetry of the Universe (BAU) and electric dipole moments (EDMs) in models extended by an extra Higgs doublet and a singlet, together with electroweak-interacting fermions. In particular, the emphasis is on the structure of the CP-violating interactions and dependences of the BAU and EDMs on masses of the relevant particles. In a concrete mode, we investigate a relationship between the BAU and the electron EDM for a typical parameter set. As long as the BAU-related CP violation predominantly exists, the electron EDM has a strong power in probing electroweak baryogenesis. However, once a BAU-unrelated CP violation comes into play, the direct correlation between the BAU and electron EDM can be lost. Even in such a case, we point out that verifiability of the scenario still remains with the help of Higgs physics.

  20. Toward verification of electroweak baryogenesis by electric dipole moments

    Energy Technology Data Exchange (ETDEWEB)

    Fuyuto, Kaori, E-mail: fuyuto@th.phys.nagoya-u.ac.jp [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Hisano, Junji, E-mail: hisano@eken.phys.nagoya-u.ac.jp [Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya University, Nagoya 464-8602 (Japan); Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Kavli IPMU (WPI), University of Tokyo, Kashiwa, Chiba 277-8584 (Japan); Senaha, Eibun, E-mail: senaha@ncu.edu.tw [Department of Physics and Center for Mathematics and Theoretical Physics, National Central University, Taoyuan, 32001, Taiwan (China)

    2016-04-10

    We study general aspects of the CP-violating effects on the baryon asymmetry of the Universe (BAU) and electric dipole moments (EDMs) in models extended by an extra Higgs doublet and a singlet, together with electroweak-interacting fermions. In particular, the emphasis is on the structure of the CP-violating interactions and dependences of the BAU and EDMs on masses of the relevant particles. In a concrete mode, we investigate a relationship between the BAU and the electron EDM for a typical parameter set. As long as the BAU-related CP violation predominantly exists, the electron EDM has a strong power in probing electroweak baryogenesis. However, once a BAU-unrelated CP violation comes into play, the direct correlation between the BAU and electron EDM can be lost. Even in such a case, we point out that verifiability of the scenario still remains with the help of Higgs physics.

  1. Recurrent giant juvenile fibroadenoma

    Directory of Open Access Journals (Sweden)

    Kathryn S. King

    2017-11-01

    Full Text Available Breast masses in children, though rare, present a difficult clinical challenge as they can represent a wide variety of entities from benign fibroadenomas to phyllodes tumors. Rapidly growing or recurrent masses can be particularly concerning to patients, families and physicians alike. Clinical examination and conventional imaging modalities are not efficacious in distinguishing between different tumor types and surgical excision is often recommended for both final diagnosis and for treatment of large or rapidly growing masses. While surgical excision can result in significant long-term deformity of the breast there are some surgical techniques that can be used to limit deformity and/or aid in future reconstruction. Here we present a case of recurrent giant juvenile fibroadenoma with a review of the clinical presentation, diagnostic tools and treatment options.

  2. Maxillomandibular giant osteosclerotic lesions

    Directory of Open Access Journals (Sweden)

    Constantino LEDESMA-MONTES

    2018-06-01

    Full Text Available Abstract Giant Osteosclerotic Lesions (GOLs are a group of rarely reported intraosseous lesions. Their precise diagnosis is important since they can be confused with malignant neoplasms. Objective This retrospective study aimed to record and analyze the clinical and radiographic Giant Osteosclerotic Lesions (GOLs detected in the maxillomandibular area of patients attending to our institution. Materials and Methods: Informed consent from the patients was obtained and those cases of 2.5 cm or larger lesions with radiopaque or mixed (radiolucid-radiopaque appearance located in the maxillofacial bones were selected. Assessed parameters were: age, gender, radiographic aspect, shape, borders, size, location and relations to roots. Lesions were classified as radicular, apical, interradicular, interradicular-apical, radicular-apical or located in a previous teeth extraction area. Additionally, several osseous and dental developmental alterations (DDAs were assessed. Results Seventeen radiopacities in 14 patients were found and were located almost exclusively in mandible and were two types: idiopathic osteosclerosis and condensing osteitis. GOLs were more frequent in females, and in the anterior and premolar zones. 94.2% of GOLs were qualified as idiopathic osteosclerosis and one case was condensing osteitis. All studied cases showed different osseous and dental developmental alterations (DDAs. The most common were: Microdontia, hypodontia, pulp stones, macrodontia and variations in the mental foramina. Conclusions GOLs must be differentiated from other radiopaque benign and malignant tumors. Condensing osteitis, was considered an anomalous osseous response induced by a chronic low-grade inflammatory stimulus. For development of idiopathic osteosclerosis, two possible mechanisms could be related. The first is modification of the normal turnover with excessive osseous deposition. The second mechanism will prevent the normal bone resorption, arresting the

  3. Engineering electric and magnetic dipole coupling in arrays of dielectric nanoparticles

    Science.gov (United States)

    Li, Jiaqi; Verellen, Niels; Van Dorpe, Pol

    2018-02-01

    Dielectric nanoparticles with both strong electric and magnetic dipole (ED and MD) resonances offer unique opportunities for efficient manipulation of light-matter interactions. Here, based on numerical simulations, we show far-field diffractive coupling of the ED and MD modes in a periodic rectangular array. By using unequal periodicities in the orthogonal directions, each dipole mode is separately coupled and strongly tuned. With this method, the electric and magnetic response of the dielectric nanoparticles can be deliberately engineered to accomplish various optical functionalities. Remarkably, an ultra-sharp MD resonance with sub-10 nm linewidth is achieved with a large enhancement factor for the magnetic field intensity on the order of ˜103. Our results will find useful applications for the detection of chemical and biological molecules as well as the design of novel photonic metadevices.

  4. Warped Dipole Completed, with a Tower of Higgs Bosons

    CERN Document Server

    Agashe, Kaustubh; Cui, Yanou; Randall, Lisa; Son, Minho

    2015-01-01

    In the context of warped extra-dimensional models which address both the Planck-weak- and flavor-hierarchies of the Standard Model (SM), it has been argued that certain observables can be calculated within the 5D effective field theory only with the Higgs field propagating in the bulk of the extra dimension, just like other SM fields. The related studies also suggested an interesting form of decoupling of the heavy Kaluza-Klein (KK) fermion states in the warped 5D SM in the limit where the profile of the SM Higgs approaches the IR brane. We demonstrate that a similar phenomenon occurs when we include the mandatory KK excitations of the SM Higgs in loop diagrams giving dipole operators for SM fermions, where the earlier work only considered the SM Higgs (zero mode). In particular, in the limit of a quasi IR-localized SM Higgs, the effect from summing over KK Higgs modes is unsuppressed (yet finite), in contrast to the naive expectation that KK Higgs modes decouple as their masses become large. In this case, a ...

  5. Modification of the Xe 4d giant resonance by the C60 shell in molecular Xe at C60

    International Nuclear Information System (INIS)

    Amusia, M. Ya.; Baltenkov, A. S.; Chernysheva, L. V.; Felfli, Z.; Msezane, A. Z.

    2006-01-01

    It is demonstrated that in photoabsorption of the 4d 10 subshell of a Xe atom in molecular Xe at C 60 , the 4d giant resonance that characterizes the isolated Xe atom is distorted significantly. The reflection of photoelectron waves by the C 60 shell leads to profound oscillations in the photoionization cross section such that the Xe giant resonance is transformed into four strong peaks. Similarly, the angular anisotropy parameters, both dipole and nondipole, are also modified. The method of calculation is based on the approximation of the C 60 shell by an infinitely thin bubble potential that leaves the sum rule for the 4d-electrons almost unaffected, but noticeably modifies the dipole polarizability of the 4d-shell

  6. Analyzing the Anomalous Dipole Moment Type Couplings of Heavy Quarks with FCNC Interactions at the CLIC

    International Nuclear Information System (INIS)

    Senol, A.; Tasci, A. T.; Verep, C.

    2014-01-01

    We examine both anomalous magnetic and dipole moment type couplings of a heavy quark via its single production with subsequent dominant standard model decay modes at the compact linear collider (CLIC). The signal and background cross sections are analyzed for heavy quark masses 600 and 700 GeV. We make the analysis to delimitate these couplings as well as to find the attainable integrated luminosities for 3σ observation limit

  7. Polarization of Magnetic Dipole Emission and Spinning Dust Emission from Magnetic Nanoparticles

    OpenAIRE

    Hoang, Thiem; Lazarian, A.

    2015-01-01

    Magnetic dipole emission (MDE) from interstellar magnetic nanoparticles is an important Galactic foreground in the microwave frequencies, and its polarization level may pose great challenges for achieving reliable measurements of cosmic microwave background (CMB) B-mode signal. To obtain theoretical constraints on the polarization of MDE, we first compute the degree of alignment of big silicate grains incorporated with magnetic inclusions. We find that, in realistic conditions of the interste...

  8. Conceptual design of Dipole Research Experiment (DREX)

    Science.gov (United States)

    Xiao, Qingmei; Wang, Zhibin; Wang, Xiaogang; Xiao, Chijie; Yang, Xiaoyi; Zheng, Jinxing

    2017-03-01

    A new terrella-like device for laboratory simulation of inner magnetosphere plasmas, Dipole Research Experiment, is scheduled to be built at the Harbin Institute of Technology (HIT), China, as a major state scientific research facility for space physics studies. It is designed to provide a ground experimental platform to reproduce the inner magnetosphere to simulate the processes of trapping, acceleration, and transport of energetic charged particles restrained in a dipole magnetic field configuration. The scaling relation of hydromagnetism between the laboratory plasma of the device and the geomagnetosphere plasma is applied to resemble geospace processes in the Dipole Research Experiment plasma. Multiple plasma sources, different kinds of coils with specific functions, and advanced diagnostics are designed to be equipped in the facility for multi-functions. The motivation, design criteria for the Dipole Research Experiment experiments and the means applied to generate the plasma of desired parameters in the laboratory are also described. Supported by National Natural Science Foundation of China (Nos. 11505040, 11261140326 and 11405038), China Postdoctoral Science Foundation (Nos. 2016M591518, 2015M570283) and Project Supported by Natural Scientific Research Innovation Foundation in Harbin Institute of Technology (No. 2017008).

  9. Installation of the ALICE dipole magnet

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    The large dipole magnet is installed on the ALICE detector at CERN. This magnet, which is cooled by demineralised water, will bend the path of muons that leave the huge rectangular solenoid (in the background). These muons are heavy electrons that interact less with matter, allowing them to traverse the main section of the detector.

  10. The isotopic dipole moment of HDO

    Energy Technology Data Exchange (ETDEWEB)

    Assafrao, Denise; Mohallem, Jose R [Laboratorio de Atomos e Moleculas Especiais, Departamento de Fisica, ICEx, Universidade Federal de Minas Gerais, CP 702, 30123-970, Belo Horizonte, MG (Brazil)

    2007-03-14

    An adiabatic variational approximation is used to study the monodeuterated water molecule, HDO, accounting for the isotopic effect. The isotopic dipole moment, pointing from D to H, is then calculated for the first time, yielding (1.5 {+-} 0.1) x 10{sup -3} Debye, being helpful in the interpretation of experiments. (fast track communication)

  11. LHC Dipoles: The countdown has begun

    CERN Document Server

    2002-01-01

    One of the LHC dipole magnets has just achieved a record magnetic field of 9 Tesla in one go without quenching. The challenge now is to increase the production rate to 35 magnets a month by 2004. As a new information panel in Building 30 shows, the countdown has begun.

  12. Forced flow cooling of ISABELLE dipole magnets

    International Nuclear Information System (INIS)

    Bamberger, J.A.; Aggus, J.; Brown, D.P.; Kassner, D.A.; Sondericker, J.H.; Strobridge, T.R.

    1976-01-01

    The superconducting magnets for ISABELLE will use a forced flow supercritical helium cooling system. In order to evaluate this cooling scheme, two individual dipole magnets were first tested in conventional dewars using pool boiling helium. These magnets were then modified for forced flow cooling and retested with the identical magnet coils. The first evaluation test used a l m-long ISA model dipole magnet whose pool boiling performance had been established. The same magnet was then retested with forced flow cooling, energizing it at various operating temperatures until quench occurred. The magnet performance with forced flow cooling was consistent with data from the previous pool boiling tests. The next step in the program was a full-scale ISABELLE dipole ring magnet, 4.25 m long, whose performance was first evaluated with pool boiling. For the forced flow test the magnet was shrunk-fit into an unsplit laminated core encased in a stainless steel cylinder. The high pressure gas is cooled below 4 K by a helium bath which is pumped below atmospheric pressure with an ejector nozzle. The performance of the full-scale dipole magnet in the new configuration with forced flow cooling, showed a 10 percent increase in the attainable maximum current as compared to the pool boiling data

  13. Dipole nano-laser: Theory and properties

    Energy Technology Data Exchange (ETDEWEB)

    Ghannam, T., E-mail: gtalal@hotmail.com [King Abdullah Institute for Nano-Technology, King Saud University, PO Box 2454, Riyadh 11451 (Saudi Arabia)

    2014-03-31

    In this paper we outline the main quantum properties of the system of nano-based laser called Dipole Nano-Laser emphasizing mainly on its ability to produce coherent light and for different configurations such as different embedding materials and subjecting it to an external classical electric field.

  14. Formation of dipole vortex in the ionosphere

    International Nuclear Information System (INIS)

    Shukla, P.K.; Yu, M.Y.

    1985-01-01

    It is shown that isolated dipole vortices can exist in the F-region of the ionosphere. These are associated with the Rayleigh-Taylor and E x B 0 gradient drift instabilities. The vortices may be responsible for the rapid structuring of barium clouds as well as other phenomena observed in the upper ionosphere

  15. Fringing field measurement of dipole magnet

    International Nuclear Information System (INIS)

    Lu Hongyou; Jiang Weisheng; Mao Naifeng; Mao Xingwang

    1985-01-01

    The fringing field of a dipole magnet with a C-type circuit and homogeneous field in the gap has been measured including the distributions of fringing fields with and without magnetic shield. The measured data was analyzed by using the concept of virtual field boundary

  16. Scattering properties of point dipole interactions

    DEFF Research Database (Denmark)

    Zolotaryuk, Alexander; Christiansen, Peter Leth; Iermakova, S.V.

    2006-01-01

    dipole interactions with a renormalized coupling constant are analysed. Depending on the parameter values, all these interactions being self-adjoint extensions of the one-dimensional Schrodinger operator are shown to be divided into four types: (i) interactions will full transparency, (ii) non...

  17. Supersymmetric relations among electromagnetic dipole operators

    International Nuclear Information System (INIS)

    Graesser, Michael; Thomas, Scott

    2002-01-01

    Supersymmetric contributions to all leptonic electromagnetic dipole operators have essentially identical diagrammatic structure. With approximate slepton universality this allows the muon anomalous magnetic moment to be related to the electron electric dipole moment in terms of supersymmetric phases, and to radiative flavor changing lepton decays in terms of small violations of slepton universality. If the current discrepancy between the measured and standard model values of the muon anomalous magnetic moment is due to supersymmetry, the current bound on the electron electric dipole moment then implies that the phase of the electric dipole operator is less than 2x10 -3 . Likewise the current bound on μ→eγ decay implies that the fractional selectron-smuon mixing in the left-left mass squared matrix, δm μ-tildee-tilde) 2 /m l-tilde) 2 , is less than 10 -4 . These relations and constraints are fairly insensitive to details of the superpartner spectrum for moderate to large tan β

  18. Results on Fermilab main injector dipole measurements

    International Nuclear Information System (INIS)

    Brown, B.C.; Baiod, R.; DiMarco, J.; Glass, H.D.; Harding, D.J.; Martin, P.S.; Mishra, S.; Mokhtarani, A.; Orris, D.F.; russell, O.A.; Tompkins, J.C.; Walbridge, D.G.C.

    1995-06-01

    Measurements of the Productions run of Fermilab Main Injector Dipole magnets is underway. Redundant strength measurements provide a set of data which one can fit to mechanical and magnetic properties of the assembly. Plots of the field contribution from the steel supplement the usual plots of transfer function (B/I) vs. I in providing insight into the measured results

  19. Electric dipole moment of 3He

    International Nuclear Information System (INIS)

    Avishai, Y.; Fabre de la Ripelle, M.

    1987-01-01

    The contribution of CP violating nucleon-nucleon interaction to the electric dipole moment of 3 He is evaluated following a recent proposal for its experimental detection. Two models of CP violating interactions are used, namely, the Kobayashi-Maskawa mechanism and the occurrence of the Θ term in the QCD lagrangian. These CP violating interactions are combined with realistic strong nucleon-nucleon interactions to induce a CP forbidden component of the 3 He wave function. The matrix element of the electric dipole operator is then evaluated between CP allowed and CP forbidden components yielding the observable electric dipole moment. Using the parameters emerging from the penguin terms in the Kobaysashi-Maskawa model we obtain a result much larger than the electric dipole moment of the neutron in the same model. On the other hand, no enhancement is found for the Θ-term mechanism. A possible explanation for this difference is discussed. Numerical estimates can be given only in the Kobayashi-Maskawa model, giving d( 3 He) ≅ 10 30 e . cm. In the second mechanism, the estimate give d ( 3 He) ≅ 10 16 anti Θ. (orig.)

  20. Induced electric dipole in a quantum ring

    Energy Technology Data Exchange (ETDEWEB)

    Dantas, L.; Furtado, Claudio, E-mail: furtado@fisica.ufpb.br

    2013-12-02

    In this contribution, we investigate the quantum dynamics of a neutral particle confined in a quantum ring potential. We use two different field configurations for induced electric dipole in the presence of electric and magnetic fields and a general confining potential, for which we solve the Schrödinger equation and obtain the complete set of eigenfunctions and eigenvalues.

  1. Search for a neutron electric dipole moment

    Energy Technology Data Exchange (ETDEWEB)

    Morse, J [Rutherford Appleton Laboratory, Chilton (U.K.)

    1984-03-01

    To search for evidence of a breakdown of symmetry under the time reversal transformation, a magnetic resonance measurement is made to detect an electric dipole moment (EDM) of ultracold neutrons stored for periods approximately= 60s in the presence of a strong electric field. The measured neutron EDM is (0.3 +- 4.8) x 10/sup -25/ ecm.

  2. Collective motion and giant resonances

    International Nuclear Information System (INIS)

    Wilhelmi, Z.; Kicinska-Habior, M.

    1984-01-01

    The report contains 15 papers devoted to problems of giant collective excitations of nuclei, heavy-ion induced reactions and their bearing on various aspects of nuclear structure. In some of them the numerical data are given. (A.S.)

  3. Ionization of Rb Rydberg atoms in the attractive nsnp dipole-dipole potential

    International Nuclear Information System (INIS)

    Park, Hyunwook; Shuman, E. S.; Gallagher, T. F.

    2011-01-01

    We have observed the ionization of a cold gas of Rb Rydberg atoms which occurs when nsns van der Waals pairs of ns atoms of n≅ 40 on a weakly repulsive potential are transferred to an attractive dipole-dipole nsnp potential by a microwave transition. Comparing the measurements to a simple model shows that the initial 300-μK thermal velocity of the atoms plays an important role. Excitation to a repulsive dipole-dipole potential does not lead to more ionization on a 15-μs time scale than leaving the atoms in the weakly repulsive nsns state. This observation is slightly surprising since a radiative transition must occur to allow ionization in the latter case. Finally, by power broadening of the microwave transition, to allow transitions from the initial nsns state to the nsnp state over a broad range of internuclear spacings, it is possible to accelerate markedly the evolution to a plasma.

  4. A wideband (3 to 5 GHz) wide-scan connected array of dipoles with low cross polarization

    NARCIS (Netherlands)

    Cavallo, D.; Neto, A.; Gerini, G.

    2012-01-01

    A wideband, wide-scan prototype phased array of connected dipoles has been manufactured and tested from 3 to 5 GHz. The array comprises 7 × 7 elements, each fed by a loop-shaped transformer to avoid common-mode resonances. Such resonances typically affect this type of arrays, with consequent

  5. Dual Aharonov-Casher effect and persistent dipole current

    International Nuclear Information System (INIS)

    Yi, J.; Jeon, G.S.; Choi, M.Y.

    1995-01-01

    An electric dipole moving in a magnetic field acquires a nontrivial quantum phase in the appropriate configuration. It is shown that this phase is manifested by the persistent dipole current induced on a ring pierced by a line of magnetic monopoles. Such a current depends on the statistics of the dipoles, which may have interesting implications for experiments. It is also pointed out that the dipole current cannot be self-sustained

  6. Position and Momentum Entanglement of Dipole-Dipole Interacting Atoms in Optical Lattices

    Science.gov (United States)

    Opatrný, T.; Kolář, M.; Kurizki, G.

    We consider a possible realization of the position- and momentum-correlated atomic pairs that are confined to adjacent sites of two mutually shifted optical lattices and are entangled via laser-induced dipole-dipole interactions. The Einstein-Podolsky-Rosen (EPR) "paradox" [Einstein 1935] with translational variables is then modified by lattice-diffraction effects. We study a possible mechanism of creating such diatom entangled states by varying the effective mass of the atoms.

  7. Translational Entanglement of Dipole-Dipole Interacting Atoms in Optical Lattices

    OpenAIRE

    Opatrny, T.; Deb, B.; Kurizki, G.

    2003-01-01

    We propose and investigate a realization of the position- and momentum-correlated Einstein-Podolsky-Rosen (EPR) states [Phys. Rev. 47, 777 (1935)] that have hitherto eluded detection. The realization involves atom pairs that are confined to adjacent sites of two mutually shifted optical lattices and are entangled via laser-induced dipole-dipole interactions. The EPR "paradox" with translational variables is then modified by lattice-diffraction effects, and can be verified to a high degree of ...

  8. The giant resonance and the shape of hot nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Bracco, A; Camera, F; Million, B; Pignanelli, M [Milan Univ. (Italy). Ist. di Fisica; Gaardhoje, J J; Maj, A; Atac, A [Niels Bohr Inst., Copenhagen (Denmark)

    1992-08-01

    The gamma decay of the giant dipole resonance is a sensitive tool for investigating how nuclear shape changes with spin and excitation energy, but the information is coded in a subtle way, inasmuch as the shape and orientation of nuclei at finite temperature display large fluctuations. At the time of the conference, the three systems {sup 109-110}Sn, {sup 161-162}Yb and {sup 165-167}Er had recently been studied on the HECTOR spectrometer. The Sn nuclei are spherical in their ground states, and are expected to become oblate under the stress of rotation. The Yb and Er nuclei are prolate, and are expected to become first spherical, then oblate. While the patterns of the measured angular anisotropies are consistent with this general picture, many questions still remain open. 3 refs., 1 tab., 3 figs.

  9. Decay of the giant monopole resonance in heavy nuclei

    International Nuclear Information System (INIS)

    Brandenburg, S.

    1985-01-01

    In this thesis an experimental study of the properties of the giant monopole resonance (GMR) in nuclei is described. The main subject is the study of the neutron decay of the GMR in 208 Pb, and the fission decay of the GMR in 238 U. Furthermore the strength distribution and decay properties of the monopole strength in 24 Mg and 40 Ca were studied. The strength distribution of the isoscalar monopole (and also of the isoscalar dipole) strength as obtained from the angular distribution of the excited strength at small scattering angles are discussed. For the excitation of the GMR inelastic scattering at very small scattering angles, including 0 0 , of 120 MeV α-particles was employed. The experimental technique for performing this type of measurements at the KVI was developed in the course of this study and is the subject of a separate chapter. (Auth.)

  10. Optimal control of orientation and entanglement for two dipole-dipole coupled quantum planar rotors.

    Science.gov (United States)

    Yu, Hongling; Ho, Tak-San; Rabitz, Herschel

    2018-05-09

    Optimal control simulations are performed for orientation and entanglement of two dipole-dipole coupled identical quantum rotors. The rotors at various fixed separations lie on a model non-interacting plane with an applied control field. It is shown that optimal control of orientation or entanglement represents two contrasting control scenarios. In particular, the maximally oriented state (MOS) of the two rotors has a zero entanglement entropy and is readily attainable at all rotor separations. Whereas, the contrasting maximally entangled state (MES) has a zero orientation expectation value and is most conveniently attainable at small separations where the dipole-dipole coupling is strong. It is demonstrated that the peak orientation expectation value attained by the MOS at large separations exhibits a long time revival pattern due to the small energy splittings arising form the extremely weak dipole-dipole coupling between the degenerate product states of the two free rotors. Moreover, it is found that the peak entanglement entropy value attained by the MES remains largely unchanged as the two rotors are transported to large separations after turning off the control field. Finally, optimal control simulations of transition dynamics between the MOS and the MES reveal the intricate interplay between orientation and entanglement.

  11. Formation and temporal evolution of the Lamb-dipole

    DEFF Research Database (Denmark)

    Nielsen, A.H.; Juul Rasmussen, J.

    1997-01-01

    of the evolving dipoles depend on the initial condition. However, the gross properties of their evolution are only weakly dependent on the detailed structure and can be well-described by the so-called Lamb-dipole solution. The viscous decay of the Lamb-dipole, leading to an expansion and a decreasing velocity...

  12. The sympletic model for giant monopole resonances

    International Nuclear Information System (INIS)

    Oliveira, M.M.B.M.

    1985-01-01

    Following recently published articles, it's investigated how to apply the sympletic model to the study of giant monopole resonances in spherical nuclei. The results obtained agree with those already published for monopole mode energies, wave functions, radii and nuclear incompressibility of 16 O and 40 Ca nuclei. An analyse of how the spurious center-of-mass motion influence resonance energies is made. The sum rules of the monopole operator, m-bar e , o ≤ e ≤ 3, are calculated, demonstrating at first that they are conserved in the sympletic model. Then it's studied, for those sum rules, the importance of n-boson correlations in the fundamental state, which is an extension of those sum rules, of the analysis for the nuclear incompressibility, performed in above mentioned articles. (Author) [pt

  13. Bringing Low the Giants

    CERN Multimedia

    2001-01-01

    Their work goes on unseen, because they a hundred metres beneath your feet. But while the race against the clock to build the LHC has begun on the surface, teams underground are feverishly engaged to dismantle LEP and its experiments. Four months after the start of dismantling, the technical coordinators of the different experiments discuss the progress of work. Little men attack the giant ALEPH. The barrel and its two endcaps have been removed to the end of the cavern and stripped of their cables. The breaking up of the detector can now begin. At ALEPH, counting rooms removed all in one go Jean-Paul Fabre, technical coordinator at ALEPH:'After making safe the structure, the first step was to remove the wiring and cables. Some 210 cubic metres were brought out. Then the counting rooms all round the detector were taken out. They were brought up from the cavern all in one go, up through the shaft, which is 10 metres wide and 150 metres deep. They made it with 15 centimetres to spare. They have been emptied of...

  14. Giant high occipital encephalocele

    Directory of Open Access Journals (Sweden)

    Agrawal Amit

    2016-03-01

    Full Text Available Encephaloceles are rare embryological mesenchymal developmental anomalies resulting from inappropriate ossification in skull through with herniation of intracranial contents of the sac. Encephaloceles are classified based on location of the osseous defect and contents of sac. Convexity encephalocele with osseous defect in occipital bone is called occipital encephalocele. Giant occipital encephaloceles can be sometimes larger than the size of baby skull itself and they pose a great surgical challenge. Occipital encephaloceles (OE are further classified as high OE when defect is only in occipital bone above the foramen magnum, low OE when involving occipital bone and foramen magnum and occipito-cervical when there involvement of occipital bone, foramen magnum and posterior upper neural arches. Chiari III malformation can be associated with high or low occipital encephaloceles. Pre-operatively, it is essential to know the size of the sac, contents of the sac, relation to the adjacent structures, presence or absence of venous sinuses/vascular structures and osseous defect size. Sometimes it becomes imperative to perform both CT and MRI for the necessary information. Volume rendered CT images can depict the relation of osseous defect to foramen magnum and provide information about upper neural arches which is necessary in classifying these lesions.

  15. Anogenital giant seborrheic keratosis.

    Science.gov (United States)

    Wollina, Uwe; Chokoeva, Anastasiya; Tchernev, Georgi; Heinig, Birgit; Schönlebe, Jacqueline

    2017-08-01

    Seborrheic keratosis (SK) are very common benign epidermal tumors. Giant seborrheic keratosis (GSK) is a rare variant with clinical characteristics, which leads very often to misdiagnosis. A genital site of SK is very unusual clinical manifestation and although the cause is still unknown, current literature data point to a possible pathogenetic role of chronic friction and HPV infection. The rare genital localization makes Buschke-Löwenstein tumor and verrucous carcinoma important differential diagnoses. GSK may also show some clinical features of a melanoacanthoma, which makes cutaneous melanoma as another possible differential diagnosis. The clinical diagnosis of genital GSK is often a very difficult one, because the typical clinical features of GSK disappear and the most common dermoscopic features of GSK are usually not seen in the genital region lesions. The diagnosis of GSK of the anogenital area should be made only and always after the exact histological verification and variety of differential diagnosis should be carefully considered. The treatment of GSK is primary surgically. We present a rare case of GSK with concomitant HPV infection in the anogenital region of 72-year-old patient. Surgical approach was performed with excellent outcome.

  16. Dipole-dipole interactions in a hot atomic vapor and in an ultracold gas of Rydberg atoms

    Science.gov (United States)

    Sautenkov, V. A.; Saakyan, S. A.; Bronin, S. Ya; Klyarfeld, A. B.; Zelener, B. B.; Zelener, B. V.

    2018-01-01

    In our paper ideal and non-ideal gas media of neutral atoms are analyzed. The first we discuss a dipole broadening of atomic transitions in excited dilute and dense metal vapors. Then the theoretical studies of the dipole-dipole interactions in dense ultracold gas of Rydberg atoms are considered. Possible future experiments on a base of our experimental arrangement are suggested.

  17. Convective-core Overshoot and Suppression of Oscillations: Constraints from Red Giants in NGC 6811

    Energy Technology Data Exchange (ETDEWEB)

    Arentoft, T.; Brogaard, K.; Jessen-Hansen, J.; Silva Aguirre, V.; Kjeldsen, H.; Mosumgaard, J. R. [Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Sandquist, E. L., E-mail: toar@phys.au.dk [San Diego State University, Department of Astronomy, San Diego, CA 92182 (United States)

    2017-04-01

    Using data from the NASA spacecraft Kepler , we study solar-like oscillations in red giant stars in the open cluster NGC 6811. We determine oscillation frequencies, frequency separations, period spacings of mixed modes, and mode visibilities for eight cluster giants. The oscillation parameters show that these stars are helium-core-burning red giants. The eight stars form two groups with very different oscillation power spectra; the four stars with the lowest Δ ν values display rich sets of mixed l = 1 modes, while this is not the case for the four stars with higher Δ ν . For the four stars with lowest Δ ν , we determine the asymptotic period spacing of the mixed modes, Δ P , which together with the masses we derive for all eight stars suggest that they belong to the so-called secondary clump. Based on the global oscillation parameters, we present initial theoretical stellar modeling that indicates that we can constrain convective-core overshoot on the main sequence and in the helium-burning phase for these ∼2 M {sub ⊙} stars. Finally, our results indicate less mode suppression than predicted by recent theories for magnetic suppression of certain oscillation modes in red giants.

  18. Field of a dipole in charged black-hole electrostatics

    International Nuclear Information System (INIS)

    Souza, J.A.

    1979-01-01

    By using the solution of Adler and Das for Maxwell's equations in a Reissner-Nordstroem optimally charged background metric, the field of a static electric dipole is found and then, by a duality rotation, the field of a static magnetic dipole is obtained. A generalization of the concept of electric-dipole moment is proposed for static dipoles in curved manifolds, and the behaviour of the fields both for the dipole very near and very far from the singular surface of the Reissner-Nordstroem geometry is studied. (author)

  19. Projected Dipole Model for Quantum Plasmonics

    DEFF Research Database (Denmark)

    Yan, Wei; Wubs, Martijn; Mortensen, N. Asger

    2015-01-01

    of classical electrodynamics, while quantum properties are described accurately through an infinitely thin layer of dipoles oriented normally to the metal surface. The nonlocal polarizability of the dipole layer-the only introduced parameter-is mapped from the free-electron distribution near the metal surface...... as obtained with 1D quantum calculations, such as time-dependent density-functional theory (TDDFT), and is determined once and for all. The model can be applied in two and three dimensions to any system size that is tractable within classical electrodynamics, while capturing quantum plasmonic aspects......Quantum effects of plasmonic phenomena have been explored through ab initio studies, but only for exceedingly small metallic nanostructures, leaving most experimentally relevant structures too large to handle. We propose instead an effective description with the computationally appealing features...

  20. The LHC dipole test control architecture

    International Nuclear Information System (INIS)

    Gorskaya, E.; Samojlov, V.; Raimondo, A.; Rijllart, A.

    2003-01-01

    The next large accelerator project at CERN is the Large Hadron Collider, which is foreseen to be installed in the existing LEP tunnel, and scheduled to be commissioned in 2007. For this project, 1200 15-metre long dipole magnets need to be tested at CERN in warm and cold conditions on dedicated test benches that are under development. The final LHC dipole series test set-up will consist of 12 benches organized in 6 clusters of two benches sharing the largest and most expensive devices. This sharing is made possible by a deliberate de-phasing of the tests among magnets, ensuring an optimum use of resources, such as cryogenics and power equipment, without limiting the total throughput. An offered two-level control architecture includes: 1) the Test 'Master' that drives the test for a cluster; 2) the Resource 'Manager' that allocates common devices and central resources. The implementation of this architecture is done in the LabVIEW environment

  1. Broadband standard dipole antenna for antenna calibration

    Science.gov (United States)

    Koike, Kunimasa; Sugiura, Akira; Morikawa, Takao

    1995-06-01

    Antenna calibration of EMI antennas is mostly performed by the standard antenna method at an open-field test site using a specially designed dipole antenna as a reference. In order to develop broadband standard antennas, the antenna factors of shortened dipples are theoretically investigated. First, the effects of the dipole length are analyzed using the induced emf method. Then, baluns and loads are examined to determine their influence on the antenna factors. It is found that transformer-type baluns are very effective for improving the height dependence of the antenna factors. Resistive loads are also useful for flattening the frequency dependence. Based on these studies, a specification is developed for a broadband standard antenna operating in the 30 to 150 MHz frequency range.

  2. Electric Dipole Moment Results from lattice QCD

    Science.gov (United States)

    Dragos, Jack; Luu, Thomas; Shindler, Andrea; de Vries, Jordy

    2018-03-01

    We utilize the gradient flow to define and calculate electric dipole moments induced by the strong QCD θ-term and the dimension-6 Weinberg operator. The gradient flow is a promising tool to simplify the renormalization pattern of local operators. The results of the nucleon electric dipole moments are calculated on PACS-CS gauge fields (available from the ILDG) using Nf = 2+1, of discrete size 323×64 and spacing a ≃ 0.09 fm. These gauge fields use a renormalization-group improved gauge action and a nonperturbatively O(a) improved clover quark action at β = 1.90, with cSW = 1.715. The calculation is performed at pion masses of mπ ≃ 411, 701 MeV.

  3. Electric Dipole Moment Results from lattice QCD

    Directory of Open Access Journals (Sweden)

    Dragos Jack

    2018-01-01

    Full Text Available We utilize the gradient flow to define and calculate electric dipole moments induced by the strong QCD θ-term and the dimension-6 Weinberg operator. The gradient flow is a promising tool to simplify the renormalization pattern of local operators. The results of the nucleon electric dipole moments are calculated on PACS-CS gauge fields (available from the ILDG using Nf = 2+1, of discrete size 323×64 and spacing a ≃ 0.09 fm. These gauge fields use a renormalization-group improved gauge action and a nonperturbatively O(a improved clover quark action at β = 1.90, with cSW = 1.715. The calculation is performed at pion masses of mπ ≃ 411, 701 MeV.

  4. Energy flow of electric dipole radiation in between parallel mirrors

    Science.gov (United States)

    Xu, Zhangjin; Arnoldus, Henk F.

    2017-11-01

    We have studied the energy flow patterns of the radiation emitted by an electric dipole located in between parallel mirrors. It appears that the field lines of the Poynting vector (the flow lines of energy) can have very intricate structures, including many singularities and vortices. The flow line patterns depend on the distance between the mirrors, the distance of the dipole to one of the mirrors and the angle of oscillation of the dipole moment with respect to the normal of the mirror surfaces. Already for the simplest case of a dipole moment oscillating perpendicular to the mirrors, singularities appear at regular intervals along the direction of propagation (parallel to the mirrors). For a parallel dipole, vortices appear in the neighbourhood of the dipole. For a dipole oscillating under a finite angle with the surface normal, the radiating tends to swirl around the dipole before travelling off parallel to the mirrors. For relatively large mirror separations, vortices appear in the pattern. When the dipole is off-centred with respect to the midway point between the mirrors, the flow line structure becomes even more complicated, with numerous vortices in the pattern, and tiny loops near the dipole. We have also investigated the locations of the vortices and singularities, and these can be found without any specific knowledge about the flow lines. This provides an independent means of studying the propagation of dipole radiation between mirrors.

  5. Bosonic and fermionic dipoles on a ring

    DEFF Research Database (Denmark)

    Zöllner, Sascha; Pethick, C. J.; Bruun, Georg Morten

    2011-01-01

    We show that dipolar bosons and fermions confined in a quasi-one-dimensional ring trap exhibit a rich variety of states because their interaction is inhomogeneous. For purely repulsive interactions, with increasing strength of the dipolar coupling there is a crossover from a gaslike state...... to an inhomogeneous crystal-like one. For small enough angles between the dipoles and the plane of the ring, there are regions with attractive interactions, and clustered states can form....

  6. The LHC AC Dipole system: an introduction

    CERN Document Server

    Serrano, J; CERN. Geneva. BE Department

    2010-01-01

    The LHC AC Dipole is an instrument to study properties of the LHC lattice by inducing large transverse displacements in the beam. These displacements are generated by exciting the beam with an oscillating magnetic field at a frequency close to the tune. This paper presents the system requirements and the technical solution chosen to meet them, based of high-power audio amplifiers and a resonant parallel RLC circuit.

  7. Field quality of LHC superconducting dipole magnets

    International Nuclear Information System (INIS)

    Mishra, R.K.

    2003-01-01

    The author reports here the main results of field measurements performed so far on the LHC superconducting dipoles at superfluid helium temperature. The main field strength at injection, collision conditions and higher order multipoles are discussed. Superconducting magnets exhibit additional field imperfections due to diamagnetic properties of superconducting cables, apart from geometric error, saturation of iron yoke and eddy currents error. Dynamic effects on field harmonics, such as field decay at injection and subsequent snap back are also discussed. (author)

  8. 15 T And Beyond - Dipoles and Quadrupoles

    International Nuclear Information System (INIS)

    Sabbi, GianLuca

    2008-01-01

    Starting with the invention of the cyclotron by Lawrence, accelerator-based experiments have been the primary source of new discoveries in particle physics. In order to progress toward higher energy and luminosity, higher field magnets are required. R and D programs are underway to take advantage of new developments in superconducting materials, achieve better efficiency and simplify magnet fabrication while preserving accelerator-class field quality. A review of recent progress on high field dipole and quadrupole magnets is presented.

  9. Extended equivalent dipole model for radiated emissions

    OpenAIRE

    Obiekezie, Chijioke S.

    2016-01-01

    This work is on the characterisation of radiated fields from electronic devices. An equivalent dipole approach is used. Previous work showed that this was an effective approach for single layer printed circuit boards where an infinite ground plane can be assumed. In this work, this approach is extended for the characterisation of more complex circuit boards or electronic systems.\\ud For complex electronic radiators with finite ground planes, the main challenge is characterising field diffract...

  10. Electric dipole transitions of heavy quarkonium

    Energy Technology Data Exchange (ETDEWEB)

    Pietrulewicz, Piotr [Universitaet Wien (Austria)

    2012-07-01

    In this talk we present the theoretical treatment of electric dipole transitions of heavy quarkonia within an effective field theory formalism. Inside the effective field theory called potential nonrelativistic QCD (pNRQCD) we account for the relativistic corrections to the decay rate in a systematic and model-independent way. Former results from potential model calculations are scrutinized, and a phenomenological analysis in relation to the experimental data is presented.

  11. CP-violation and electric dipole moments

    Energy Technology Data Exchange (ETDEWEB)

    Le Dall, Matthias; Ritz, Adam, E-mail: aritz@uvic.ca [University of Victoria, Department of Physics and Astronomy (Canada)

    2013-03-15

    Searches for intrinsic electric dipole moments of nucleons, atoms and molecules are precision flavour-diagonal probes of new -odd physics. We review and summarise the effective field theory analysis of the observable EDMs in terms of a general set of CP-odd operators at 1 GeV, and the ensuing model-independent constraints on new physics. We also discuss the implications for supersymmetric models, in light of the mass limits emerging from the LHC.

  12. Magnetic field modification of optical magnetic dipoles.

    Science.gov (United States)

    Armelles, Gaspar; Caballero, Blanca; Cebollada, Alfonso; Garcia-Martin, Antonio; Meneses-Rodríguez, David

    2015-03-11

    Acting on optical magnetic dipoles opens novel routes to govern light-matter interaction. We demonstrate magnetic field modification of the magnetic dipolar moment characteristic of resonant nanoholes in thin magnetoplasmonic films. This is experimentally shown through the demonstration of the magneto-optical analogue of Babinet's principle, where mirror imaged MO spectral dependencies are obtained for two complementary magnetoplasmonic systems: holes in a perforated metallic layer and a layer of disks on a substrate.

  13. SPS Dipole Multipactor Test and TEWave Diagnostics

    CERN Document Server

    Caspers, F; Edwards, P; Federmann, S; Holz, M; Taborelli, M

    2013-01-01

    Electron cloud accumulation in particle accelerators can be mitigated by coating the vacuum beam pipe with thin films of low secondary electron yield (SEY) material. The SEY of small coated samples are usually measured in the laboratory. To further test the properties of different coating materials, RF-induced multipacting in a coaxial waveguide configuration can be performed. The technique is applied to two main bending dipoles of the SPS, where the RF power is fed through a tungsten wire stretched along the vacuum chamber (6.4 m). A dipole with a bare stainless steel chamber shows a clear power threshold initiating an abrupt rise in reflected power and pressure. The effect is enhanced at RF frequencies corresponding to electron cyclotron resonances for given magnetic fields. Preliminary results show that the dipole with a carbon coated vacuum chamber does not exhibit any pressure rise or reflected RF power up to the maximum available input power. In the case of a large scale coating production this techniqu...

  14. Direct amplitude detuning measurement with ac dipole

    Directory of Open Access Journals (Sweden)

    S. White

    2013-07-01

    Full Text Available In circular machines, nonlinear dynamics can impact parameters such as beam lifetime and could result in limitations on the performance reach of the accelerator. Assessing and understanding these effects in experiments is essential to confirm the accuracy of the magnetic model and improve the machine performance. A direct measurement of the machine nonlinearities can be obtained by characterizing the dependency of the tune as a function of the amplitude of oscillations (usually defined as amplitude detuning. The conventional technique is to excite the beam to large amplitudes with a single kick and derive the tune from turn-by-turn data acquired with beam position monitors. Although this provides a very precise tune measurement it has the significant disadvantage of being destructive. An alternative, nondestructive way of exciting large amplitude oscillations is to use an ac dipole. The perturbation Hamiltonian in the presence of an ac dipole excitation shows a distinct behavior compared to the free oscillations which should be correctly taken into account in the interpretation of experimental data. The use of an ac dipole for direct amplitude detuning measurement requires careful data processing allowing one to observe the natural tune of the machine; the feasibility of such a measurement is demonstrated using experimental data from the Large Hadron Collider. An experimental proof of the theoretical derivations based on measurements performed at injection energy is provided as well as an application of this technique at top energy using a large number of excitations on the same beam.

  15. Neutrino production of single pions: Dipole description

    International Nuclear Information System (INIS)

    Kopeliovich, B. Z.; Schmidt, Ivan; Siddikov, M.

    2011-01-01

    The light-cone distribution amplitudes for the axial current are derived within the instanton vacuum model, which incorporates nonperturbative effects including spontaneous chiral symmetry breaking. This allows one to extend applicability of the dipole approach, usually used in the perturbative domain, down to Q 2 →0, where the partially conserved axial current imposes a relation between the neutrino-production cross section and the one induced by pions. A dramatic breakdown of the Adler relation for diffractive neutrino production of pions, caused by absorptive corrections, was revealed recently by Kopeliovich et al.. Indeed, comparing with the cross section predicted by the dipole phenomenology at Q 2 →0 on a proton target we confirmed the sizable deviation from the value given by the Adler relation, as was estimated by Kopeliovich et al. within a simplified two-channel model. The dipole approach also confirms that in the black-disk limit, where the absorptive corrections maximize, the diffractive cross section ceases, on the contrary to the expectation based on the partially conserved axial current.

  16. Local electric dipole moments: A generalized approach.

    Science.gov (United States)

    Groß, Lynn; Herrmann, Carmen

    2016-09-30

    We present an approach for calculating local electric dipole moments for fragments of molecular or supramolecular systems. This is important for understanding chemical gating and solvent effects in nanoelectronics, atomic force microscopy, and intensities in infrared spectroscopy. Owing to the nonzero partial charge of most fragments, "naively" defined local dipole moments are origin-dependent. Inspired by previous work based on Bader's atoms-in-molecules (AIM) partitioning, we derive a definition of fragment dipole moments which achieves origin-independence by relying on internal reference points. Instead of bond critical points (BCPs) as in existing approaches, we use as few reference points as possible, which are located between the fragment and the remainder(s) of the system and may be chosen based on chemical intuition. This allows our approach to be used with AIM implementations that circumvent the calculation of critical points for reasons of computational efficiency, for cases where no BCPs are found due to large interfragment distances, and with local partitioning schemes other than AIM which do not provide BCPs. It is applicable to both covalently and noncovalently bound systems. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  17. Quantum calculations of the IR spectrum of liquid water using ab initio and model potential and dipole moment surfaces and comparison with experiment

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hanchao; Wang, Yimin; Bowman, Joel M. [Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322 (United States)

    2015-05-21

    The calculation and characterization of the IR spectrum of liquid water have remained a challenge for theory. In this paper, we address this challenge using a combination of ab initio approaches, namely, a quantum treatment of IR spectrum using the ab initio WHBB water potential energy surface and a refined ab initio dipole moment surface. The quantum treatment is based on the embedded local monomer method, in which the three intramolecular modes of each embedded H{sub 2}O monomer are fully coupled and also coupled singly to each of six intermolecular modes. The new dipole moment surface consists of a previous spectroscopically accurate 1-body dipole moment surface and a newly fitted ab initio intrinsic 2-body dipole moment. A detailed analysis of the new dipole moment surface in terms of the coordinate dependence of the effective atomic charges is done along with tests of it for the water dimer and prism hexamer double-harmonic spectra against direct ab initio calculations. The liquid configurations are taken from previous molecular dynamics calculations of Skinner and co-workers, using the TIP4P plus E3B rigid monomer water potential. The IR spectrum of water at 300 K in the range of 0–4000 cm{sup −1} is calculated and compared with experiment, using the ab initio WHBB potential and new ab initio dipole moment, the q-TIP4P/F potential, which has a fixed-charged description of the dipole moment, and the TTM3-F potential and dipole moment surfaces. The newly calculated ab initio spectrum is in very good agreement with experiment throughout the above spectral range, both in band positions and intensities. This contrasts to results with the other potentials and dipole moments, especially the fixed-charge q-TIP4P/F model, which gives unrealistic intensities. The calculated ab initio spectrum is analyzed by examining the contribution of various transitions to each band.

  18. Quantum calculations of the IR spectrum of liquid water using ab initio and model potential and dipole moment surfaces and comparison with experiment

    International Nuclear Information System (INIS)

    Liu, Hanchao; Wang, Yimin; Bowman, Joel M.

    2015-01-01

    The calculation and characterization of the IR spectrum of liquid water have remained a challenge for theory. In this paper, we address this challenge using a combination of ab initio approaches, namely, a quantum treatment of IR spectrum using the ab initio WHBB water potential energy surface and a refined ab initio dipole moment surface. The quantum treatment is based on the embedded local monomer method, in which the three intramolecular modes of each embedded H 2 O monomer are fully coupled and also coupled singly to each of six intermolecular modes. The new dipole moment surface consists of a previous spectroscopically accurate 1-body dipole moment surface and a newly fitted ab initio intrinsic 2-body dipole moment. A detailed analysis of the new dipole moment surface in terms of the coordinate dependence of the effective atomic charges is done along with tests of it for the water dimer and prism hexamer double-harmonic spectra against direct ab initio calculations. The liquid configurations are taken from previous molecular dynamics calculations of Skinner and co-workers, using the TIP4P plus E3B rigid monomer water potential. The IR spectrum of water at 300 K in the range of 0–4000 cm −1 is calculated and compared with experiment, using the ab initio WHBB potential and new ab initio dipole moment, the q-TIP4P/F potential, which has a fixed-charged description of the dipole moment, and the TTM3-F potential and dipole moment surfaces. The newly calculated ab initio spectrum is in very good agreement with experiment throughout the above spectral range, both in band positions and intensities. This contrasts to results with the other potentials and dipole moments, especially the fixed-charge q-TIP4P/F model, which gives unrealistic intensities. The calculated ab initio spectrum is analyzed by examining the contribution of various transitions to each band

  19. Formation of giant planets

    International Nuclear Information System (INIS)

    Perri, F.

    1975-01-01

    When a planetary core composed of condensed matter is accumulated in the primitive solar nebula, the gas of the nebula becomes gravitationally concentrated as an envelope surrounding the planetary core. Models of such gaseous envelopes have been constructed subject to the assumption that the gas everywhere is on the same adiabat as that in the surrounding nebula. The gaseous envelope extends from the surface of the core to the distance at which the gravitational attraction of core plus envelope becomes equal to the gradient of the gravitational potential in the solar nebula; at this point the pressure and temperature of the gas in the envelope are required to attain the background values characteristic of the solar nebula. In general, as the mass of the condensed core increases, increasing amounts of gas became concentrated in the envelope, and these envelopes are stable against hydrodynamic instabilities. However, the core mass then goes through a maximum and starts to decrease. In most of the models tested the envelopes were hydrodynamically unstable beyond the peak in the core mass. An unstable situation was always created if it was insisted that the core mass contain a larger amount of matter than given by these solutions. For an initial adiabat characterized by a temperature of 450 0 K and a pressure of 5 x 10 -6 atmospheres, the maximum core mass at which instability occurs is approximately 115 earth masses. It is concluded that the giant planets obtained their large amounts of hydrogen and helium by a hydrodynamic collapse process in the solar nebula only after the nebula had been subjected to a considerable period of cooling

  20. A Study on the Transversal Optical Mode in Amorphous Gallium Arsenide

    OpenAIRE

    Grado-Caffaro, M. A.; Grado-Caffaro, M.

    1998-01-01

    Contributions to the far-infrared spectrum corresponding to both dynamical and structural disorders in a-GaAs are examined when frequency coincides with the transversal optical mode. Under these circumstances, dipole moment matrix element is discussed.

  1. Giant amplification in degenerate band edge slow-wave structures interacting with an electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Mohamed A. K.; Veysi, Mehdi; Capolino, Filippo [Department of Electrical Engineering and Computer Science, University of California, Irvine, California 92697 (United States); Figotin, Alexander [Department of Mathematics, University of California, Irvine, California 92697 (United States)

    2016-03-15

    We propose a new amplification regime based on a synchronous operation of four degenerate electromagnetic (EM) modes in a slow-wave structure and the electron beam, referred to as super synchronization. These four EM modes arise in a Fabry-Pérot cavity when degenerate band edge (DBE) condition is satisfied. The modes interact constructively with the electron beam resulting in superior amplification. In particular, much larger gains are achieved for smaller beam currents compared to conventional structures based on synchronization with only a single EM mode. We demonstrate giant gain scaling with respect to the length of the slow-wave structure compared to conventional Pierce type single mode traveling wave tube amplifiers. We construct a coupled transmission line model for a loaded waveguide slow-wave structure exhibiting a DBE, and investigate the phenomenon of giant gain via super synchronization using the Pierce model generalized to multimode interaction.

  2. Polarized photon scattering of 52Cr: Determining the parity of dipole states

    Science.gov (United States)

    Krishichayan, Fnu; Bhike, M.; Tornow, W.

    2014-03-01

    Observation of dipole states in nuclei are important because they provide information on various collective and single-particle nuclear excitation modes, e.g., pygmy dipole resonance (PDR) and spin-flip M1 resonance. The PDR has been extensively studied in the higher and medium mass region, whereas not much information is available around the low mass (A ~ 50) region where, apparently,the PDR starts to form. The present photoresponse of 52Cr has been investigated to test the evolution of the PDR in a nucleus with a small number of excess neutrons as well as to look for spin-flip M1 resonance excitation mode. Spin-1 states in 52Cr between 5.0 to 9.5 MeV excitation energy were excited by exploiting fully polarized photons using the (γ ,γ') nuclear resonance fluorescence technique, a completely model-independent electromagnetic method. The de-excitation γ-rays were detected using a HPGe array. The experiment was carried out using the HIGS facility at TUNL. Results of unambiguous parity determinations of dipole states in 52Cr will be presented.

  3. Giant lobelias exemplify convergent evolution

    Directory of Open Access Journals (Sweden)

    Givnish Thomas J

    2010-01-01

    Full Text Available Abstract Giant lobeliads on tropical mountains in East Africa and Hawaii have highly unusual, giant-rosette growth forms that appear to be convergent on each other and on those of several independently evolved groups of Asteraceae and other families. A recent phylogenetic analysis by Antonelli, based on sequencing the widest selection of lobeliads to date, raises doubts about this paradigmatic example of convergent evolution. Here I address the kinds of evidence needed to test for convergent evolution and argue that the analysis by Antonelli fails on four points. Antonelli's analysis makes several important contributions to our understanding of lobeliad evolution and geographic spread, but his claim regarding convergence appears to be invalid. Giant lobeliads in Hawaii and Africa represent paradigmatic examples of convergent evolution.

  4. CMB lensing and giant rings

    Energy Technology Data Exchange (ETDEWEB)

    Rathaus, Ben; Itzhaki, Nissan, E-mail: nitzhaki@post.tau.ac.il, E-mail: ben.rathaus@gmail.com [Raymond and Beverly Sackler Faculty of Exact Sciences, School of Physics and Astronomy, Tel-Aviv University, Ramat-Aviv, 69978 (Israel)

    2012-05-01

    We study the CMB lensing signature of a pre-inationary particle (PIP), assuming it is responsible for the giant rings anomaly that was found recently in the WMAP data. Simulating Planck-like data we find that generically the CMB lensing signal to noise ratio associated with such a PIP is quite small and it would be difficult to cross correlate the temperature giant rings with the CMB lensing signal. However, if the pre-inationary particle is also responsible for the bulk flow measured from the local large scale structure, which happens to point roughly at the same direction as the giant rings, then the CMB lensing signal to noise ratio is fairly significant.

  5. An engineered CARS substrate with giant field enhancement in crisscross dimer nanostructure.

    Science.gov (United States)

    Zhang, Jia; Chen, Shu; Wang, Junqiao; Mu, Kaijun; Fan, Chunzhen; Liang, Erjun; Ding, Pei

    2018-01-15

    We theoretically investigate the optical properties of a nanostructure consisting of the two identical and symmetrically arranged crisscrosses. A plasmonic Fano resonance is induced by a strong interplay between bright mode and dark modes, where the bright mode is due to electric dipole resonance while dark modes originate from the magnetic dipole induced by LC resonances. In this article, we find that the electric field "hotspots" corresponding to three different wavelengths can be positioned at the same spatial position, and its spectral tunability is achieved by changing geometric parameters. The crisscrosses system can be designed as a plasmonic substrate for enhancing Coherent Anti-Stokes Raman Scattering (CARS) signal. This discovery provides a new method to achieve single molecule detection. At the same time, it also has many important applications for multi-photon imaging and other nonlinear optical processes, such as four-wave mixing and stimulated Raman scattering.

  6. Imaging of giant pituitary adenomas

    Energy Technology Data Exchange (ETDEWEB)

    Majos, C.; Coll, S.; Aguilera, C.; Pons, L.C. [Bellvitge Univ., Barcelona (Spain). Inst. de Diagnostice per la Imatge; Acebes, J.J. [Department of Neurosurgery, Ciutat Sanitaria i Universitaria de Bellvitge, L`Hospitalet de Llobregat, Barcelona (Spain)

    1998-10-01

    We present five proven giant pituitary adenomas studied by CT and MRI, and review the clinical and imaging findings. Our aim was to examine the radiologic appearances and to search for criteria useful in distinguishing these tumors from other sellar and suprasellar tumours, mainly craniopharyngioma. The main differences from small adenomas were high prevalence of macrocysts, a more invasive behaviour and a clinical picture dominated by mass effect rather than endocrine disturbance. Factors supporting the diagnosis of pituitary adenoma in a giant intra- and suprasellar mass include: infrasellar extension, absence of calcification and presence of low-signal cysts on T1-weighted images. (orig.) (orig.) With 4 figs., 2 tabs., 9 refs.

  7. [Giant intradiploic infratentorial epidermoid cyst].

    Science.gov (United States)

    Alberione, F; Caire, F; Fischer-Lokou, D; Gueye, M; Moreau, J J

    2007-10-01

    Epidermoid cysts are benign, uncommon lesions (1% of all intracranial tumors). Their localization is intradiploic in 25% of cases, and exceptionally subtentorial. We report here a rare case of giant intradiploic infratentorial epidermoid cyst. A 74-year old patient presented with recent diplopia and sindrome cerebellar. CT scan and MR imaging revealed a giant osteolytic extradural lesion of the posterior fossa (5.2 cm x 3.8 cm) with a small area of peripheral enhancement after contrast injection. Retrosigmoid suboccipital craniectomy allowed a satisfactory removal of the tumor, followed by an acrylic cranioplasty. The outcome was good. Neuropathological examination confirmed an epidermoid cyst. We review the literature and discuss our case.

  8. Percolation with multiple giant clusters

    International Nuclear Information System (INIS)

    Ben-Naim, E; Krapivsky, P L

    2005-01-01

    We study mean-field percolation with freezing. Specifically, we consider cluster formation via two competing processes: irreversible aggregation and freezing. We find that when the freezing rate exceeds a certain threshold, the percolation transition is suppressed. Below this threshold, the system undergoes a series of percolation transitions with multiple giant clusters ('gels') formed. Giant clusters are not self-averaging as their total number and their sizes fluctuate from realization to realization. The size distribution F k , of frozen clusters of size k, has a universal tail, F k ∼ k -3 . We propose freezing as a practical mechanism for controlling the gel size. (letter to the editor)

  9. Statistical decay of giant resonances

    International Nuclear Information System (INIS)

    Dias, H.; Teruya, N.; Wolynec, E.

    1986-01-01

    Statistical calculations to predict the neutron spectrum resulting from the decay of Giant Resonances are discussed. The dependence of the resutls on the optical potential parametrization and on the level density of the residual nucleus is assessed. A Hauser-Feshbach calculation is performed for the decay of the monople giant resonance in 208 Pb using the experimental levels of 207 Pb from a recent compilation. The calculated statistical decay is in excelent agreement with recent experimental data, showing that the decay of this resonance is dominantly statistical, as predicted by continuum RPA calculations. (Author) [pt

  10. Statistical decay of giant resonances

    International Nuclear Information System (INIS)

    Dias, H.; Teruya, N.; Wolynec, E.

    1986-02-01

    Statistical calculations to predict the neutron spectrum resulting from the decay of Giant Resonances are discussed. The dependence of the results on the optical potential parametrization and on the level density of the residual nucleus is assessed. A Hauser-Feshbach calculation is performed for the decay of the monopole giant resonance in 208 Pb using the experimental levels of 207 Pb from a recent compilation. The calculated statistical decay is in excellent agreement with recent experimental data, showing that decay of this resonance is dominantly statistical, as predicted by continuum RPA calculations. (Author) [pt

  11. Migration of accreting giant planets

    Science.gov (United States)

    Robert, C.; Crida, A.; Lega, E.; Méheut, H.

    2017-09-01

    Giant planets forming in protoplanetary disks migrate relative to their host star. By repelling the gas in their vicinity, they form gaps in the disk's structure. If they are effectively locked in their gap, it follows that their migration rate is governed by the accretion of the disk itself onto the star, in a so-called type II fashion. Recent results showed however that a locking mechanism was still lacking, and was required to understand how giant planets may survive their disk. We propose that planetary accretion may play this part, and help reach this slow migration regime.

  12. Spin-flip measurements in the proton inelastic scattering on 12C and giant resonance effects

    International Nuclear Information System (INIS)

    De Leo, R.; D'Erasmo, G.; Ferrero, F.; Pantaleo, A.; Pignanelli, M.

    1975-01-01

    Differential cross sections and spin-flip probabilities (SFP) for the inelastic scattering of protons, exciting the 2 + state at 4.43 MeV in 12 C, have been measured at several incident energies between 15.9 and 37.6 MeV. The changes in the shape of the SFP angular distributions are rather limited, while the absolute values show a pronounced increase, resonant like, in two energy regions centered at about 20 and 29 MeV. The second resonance reproduces very closely the energy dependence of the E2 giant quadrupole strength found in a previous experiment. The resonance at 20 MeV should correspond to a substructure of the E1 giant dipole resonance. (Auth.)

  13. Dramatic distortion of the 4d giant resonance by the C{sub 60} fullerene shell

    Energy Technology Data Exchange (ETDEWEB)

    Amusia, M Ya [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel); Baltenkov, A S [Arifov Institute of Electronics, Akademgorodok, 700125 Tashkent (Uzbekistan); Chernysheva, L V [A F Ioffe Physical-Technical Institute, St Petersburg 194021 (Russian Federation); Felfli, Z [Department of Physics and Center for Theoretical Studies of Physical Systems, Clark Atlanta University, Atlanta, GA 30314 (United States); Msezane, A Z [Department of Physics and Center for Theoretical Studies of Physical Systems, Clark Atlanta University, Atlanta, GA 30314 (United States)

    2005-05-28

    The photoionization cross section for the endohedral Xe at C{sub 60} atom is investigated within the framework of representing the C{sub 60} by a delta-type potential. Results demonstrate that in Xe at C{sub 60}, the 4d giant resonance is distorted significantly when compared with that of the isolated Xe atom. The reflection of the photoelectron waves by the C{sub 60} causes strong oscillations in the photoionization cross section resulting in the replacement of the Xe 4d giant resonance by four prominent peaks. The approximation of C{sub 60} by an infinitely thin real potential preserves reasonably well the sum rule for the 4d electrons but modifies the dipole polarizability of the 4d shell. (letter to the editor)

  14. Giant serpentine intracranial aneurysm: a case report

    International Nuclear Information System (INIS)

    Park, Jae Seong; Lee, Myeong Sub; Kim, Myung Soon; Kim, Dong Jin; Park, Joong Wha; Whang, Kum

    2001-01-01

    The authors present a case of giant serpentine aneurysm (a partially thrombosed aneurysm containing tortuous vascular channels with a separate entrance and outflow pathway). Giant serpentine aneurysms form a subgroup of giant intracranial aneurysms, distinct from saccular and fusiform varieties, and in this case, too, the clinical presentation and radiographic features of CT, MR imaging and angiography were distinct

  15. Giant multipole resonances: perspectives after ten years

    International Nuclear Information System (INIS)

    Bertrand, F.E.

    1980-01-01

    Nearly ten years ago evidence was published for the first of the so-called giant multipole resonances, the giant quadrupole resonance. During the ensuing years research in this field has spread to many nuclear physics laboratories throughout the world. The present status of electric giant multipole resonances is reviewed. 24 figures, 1 table

  16. Giant pulses of pulsar radio emission

    OpenAIRE

    Kuzmin, A. D.

    2007-01-01

    Review report of giant pulses of pulsar radio emission, based on our detections of four new pulsars with giant pulses, and the comparative analysis of the previously known pulsars with giant pulses, including the Crab pulsar and millisecond pulsar PSR B1937+21.

  17. Anisotropic chemical strain in cubic ceria due to oxygen-vacancy-induced elastic dipoles.

    Science.gov (United States)

    Das, Tridip; Nicholas, Jason D; Sheldon, Brian W; Qi, Yue

    2018-06-06

    Accurate characterization of chemical strain is required to study a broad range of chemical-mechanical coupling phenomena. One of the most studied mechano-chemically active oxides, nonstoichiometric ceria (CeO2-δ), has only been described by a scalar chemical strain assuming isotropic deformation. However, combined density functional theory (DFT) calculations and elastic dipole tensor theory reveal that both the short-range bond distortions surrounding an oxygen-vacancy and the long-range chemical strain are anisotropic in cubic CeO2-δ. The origin of this anisotropy is the charge disproportionation between the four cerium atoms around each oxygen-vacancy (two become Ce3+ and two become Ce4+) when a neutral oxygen-vacancy is formed. Around the oxygen-vacancy, six of the Ce3+-O bonds elongate, one of the Ce3+-O bond shorten, and all seven of the Ce4+-O bonds shorten. Further, the average and maximum chemical strain values obtained through tensor analysis successfully bound the various experimental data. Lastly, the anisotropic, oxygen-vacancy-elastic-dipole induced chemical strain is polarizable, which provides a physical model for the giant electrostriction recently discovered in doped and non-doped CeO2-δ. Together, this work highlights the need to consider anisotropic tensors when calculating the chemical strain induced by dilute point defects in all materials, regardless of their symmetry.

  18. Development of the new gamma-ray calorimeter for the measurement of Pigmy Dipole Resonance

    Science.gov (United States)

    Shikata, Mizuki; Nakamura, Takashi; Togano, Yasuhiro; Kondo, Yosuke

    2014-09-01

    A new γ-ray calorimeter CATANA (CAlorimeter for gamma γ-ray Transition in Atomic Nuclei at high isospin Asynmetry) has been developed to measure highly excited states like the pygmy dipole resonance and the giant dipole resonance. CATANA will be used with the SAMURAI spectrometer at RIBF. The excitation energy spectrum will be reconstructed combining the invariant mass of the reaction products measured by SAMURAI and γ-ray energies from CATANA. CATANA has focused on achieving a high detection efficiency. It is calculated as 56% for 1 MeV γ-rays from beam with a velocity of β = 0.6. The CATANA array consists of 200 CsI(Na) crystals and covers angles from 10 to 120 degrees along the beam axis. In this study, we have tested prototype crystals of CATANA to evaluate their performance. A position dependence of the light input have been measured and compared with a Monte-Carlo simulation based on GEANT4. In this talk, we will report the design of CATANA and the result of the tests and the simulation.

  19. Electric dipole excitation of {sup 208}Pb by polarized electron impact

    Energy Technology Data Exchange (ETDEWEB)

    Jakubassa-Amundsen, D.H. [University of Munich, Mathematics Institute, Munich (Germany); Ponomarev, V.Yu. [Technische Universitaet Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany)

    2016-03-15

    The cross sections and spin asymmetries for the excitation of 1{sup -} states in {sup 208}Pb by transversely polarized electrons with collision energy of 30-180MeV have been examined within the DWBA scattering formalism. As examples, we have considered a low-lying 1{sup -} state and also states belonging to the pygmy dipole and giant dipole resonances. The structure of these states and their corresponding transition charge and current densities have been taken from an RPA calculation within the quasiparticle phonon model. The complex-plane rotation method has been applied to achieve the convergence of the radial DWBA integrals for backward scattering. We have studied the behaviour of the cross sections and spin asymmetries as a function of electron energy and scattering angle. The role of the longitudinal and transversal contributions to the excitation has been thoroughly studied. We conclude that the spin asymmetry S, related to unpolarized outgoing electrons, is mostly well below 1% even at the backward scattering angles and its measurement provides a challenge for future experiments with polarized electrons. (orig.)

  20. Nursery of Giants

    Science.gov (United States)

    2004-01-01

    Hidden behind a shroud of dust in the constellation Cygnus is a stellar nursery called DR21, which is giving birth to some of the most massive stars in our galaxy. Visible light images reveal no trace of this interstellar cauldron because of heavy dust obscuration. In fact, visible light is attenuated in DR21 by a factor of more than 10,000,000,000,000,000,000,000,000,000,000,000,000,000 (ten thousand trillion heptillion). New images from NASA's Spitzer Space Telescope allow us to peek behind the cosmic veil and pinpoint one of the most massive natal stars yet seen in our Milky Way galaxy. The never-before-seen star is 100,000 times as bright as the Sun. Also revealed for the first time is a powerful outflow of hot gas emanating from this star and bursting through a giant molecular cloud. This image is a large-scale mosaic assembled from individual photographs obtained with the InfraRed Array Camera (IRAC) aboard Spitzer. The image covers an area about two times that of a full moon. The mosaic is a composite of images obtained at mid-infrared wavelengths of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8 microns (red). The brightest infrared cloud near the top center corresponds to DR21, which presumably contains a cluster of newly forming stars at a distance of 10,000 light-years. Protruding out from DR21 toward the bottom left of the image is a gaseous outflow (green), containing both carbon monoxide and molecular hydrogen. Data from the Spitzer spectrograph, which breaks light into its constituent individual wavelengths, indicate the presence of hot steam formed as the outflow heats the surrounding molecular gas. Outflows are physical signatures of processes that create supersonic beams, or jets, of gas. They are usually accompanied by discs of material around the new star, which likely contain the materials from which future planetary systems are formed. Additional newborn stars, depicted in green, can be seen surrounding the DR21 region

  1. Terahertz radiation-induced sub-cycle field electron emission across a split-gap dipole antenna

    International Nuclear Information System (INIS)

    Zhang, Jingdi; Averitt, Richard D.; Zhao, Xiaoguang; Fan, Kebin; Wang, Xiaoning; Zhang, Xin; Zhang, Gu-Feng; Geng, Kun

    2015-01-01

    We use intense terahertz pulses to excite the resonant mode (0.6 THz) of a micro-fabricated dipole antenna with a vacuum gap. The dipole antenna structure enhances the peak amplitude of the in-gap THz electric field by a factor of ∼170. Above an in-gap E-field threshold amplitude of ∼10 MV/cm −1 , THz-induced field electron emission is observed as indicated by the field-induced electric current across the dipole antenna gap. Field emission occurs within a fraction of the driving THz period. Our analysis of the current (I) and incident electric field (E) is in agreement with a Millikan-Lauritsen analysis where log (I) exhibits a linear dependence on 1/E. Numerical estimates indicate that the electrons are accelerated to a value of approximately one tenth of the speed of light

  2. Proposal for Translational Entanglement of Dipole-Dipole Interacting Atoms in Optical Lattices

    Science.gov (United States)

    Opatrný, Tomáš; Deb, Bimalendu; Kurizki, Gershon

    2003-06-01

    We propose and investigate a realization of the position- and momentum-correlated Einstein-Podolsky-Rosen (EPR) states [Phys. Rev. 47, 777 (1935)] that have hitherto eluded detection. The realization involves atom pairs that are confined to adjacent sites of two mutually shifted optical lattices and are entangled via laser-induced dipole-dipole interactions. The EPR “paradox” with translational variables is then modified by lattice-diffraction effects and can be verified to a high degree of accuracy in this scheme.

  3. Vortical structures for nanomagnetic memory induced by dipole-dipole interaction in monolayer disks

    Science.gov (United States)

    Liu, Zhaosen; Ciftja, Orion; Zhang, Xichao; Zhou, Yan; Ian, Hou

    2018-05-01

    It is well known that magnetic domains in nanodisks can be used as storage units for computer memory. Using two quantum simulation approaches, we show here that spin vortices on magnetic monolayer nanodisks, which are chirality-free, can be induced by dipole-dipole interaction (DDI) on the disk-plane. When DDI is sufficiently strong, vortical and anti-vortical multi-domain textures can be generated simultaneously. Especially, a spin vortex can be easily created and deleted through either external magnetic or electrical signals, making them ideal to be used in nanomagnetic memory and logical devices. We demonstrate these properties in our simulations.

  4. Electrically Small Magnetic Dipole Antennas With Quality Factors Approaching the Chu Lower Bound

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Breinbjerg, Olav; Yaghjian, Arthur D.

    2010-01-01

    We investigate the quality factor Q for electrically small current distributions and practical antenna designs radiating the TE10 magnetic dipole field. The current distributions and the antenna designs employ electric currents on a spherical surface enclosing a magneto-dielectric material...... numerically. It is found that for a given antenna size and permittivity there is an optimum permeability that ensures the lowest possible Q, and this optimum permeability is inversely proportional to the square of the antenna electrical radius. When the relative permittivity is equal to 1, the optimum...... permeability yields the quality factor Q that constitutes the lower bound for a magnetic dipole antenna with a magneto-dielectric core. Furthermore, the smaller the antenna the closer its quality factor Q can approach the Chu lower bound. Simulated results for the TE10-mode multiarm spherical helix antenna...

  5. Isoscalar and isovector giant resonances in a self-consistent phonon coupling approach

    Energy Technology Data Exchange (ETDEWEB)

    Lyutorovich, N.; Tselyaev, V. [Physical Faculty, St. Petersburg State University, RU-198504 St. Petersburg (Russian Federation); Speth, J., E-mail: J.Speth@fz-juelich.de [Institut für Kernphysik, Forschungszentrum Jülich, D-52425 Jülich (Germany); Krewald, S.; Grümmer, F. [Institut für Kernphysik, Forschungszentrum Jülich, D-52425 Jülich (Germany); Reinhard, P.-G. [Institut für Theoretische Physik II, Universität Erlangen-Nürnberg, D-91058 Erlangen (Germany)

    2015-10-07

    We present fully self-consistent calculations of isoscalar giant monopole and quadrupole as well as isovector giant dipole resonances in heavy and light nuclei. The description is based on Skyrme energy-density functionals determining the static Hartree–Fock ground state and the excitation spectra within random-phase approximation (RPA) and RPA extended by including the quasiparticle-phonon coupling at the level of the time-blocking approximation (TBA). All matrix elements were derived consistently from the given energy-density functional and calculated without any approximation. As a new feature in these calculations, the single-particle continuum was included thus avoiding the artificial discretization usually implied in RPA and TBA. The step to include phonon coupling in TBA leads to small, but systematic, down shifts of the centroid energies of the giant resonances. These shifts are similar in size for all Skyrme parametrizations investigated here. After all, we demonstrate that one can find Skyrme parametrizations which deliver a good simultaneous reproduction of all three giant resonances within TBA.

  6. Isoscalar and isovector giant resonances in a self-consistent phonon coupling approach

    Directory of Open Access Journals (Sweden)

    N. Lyutorovich

    2015-10-01

    Full Text Available We present fully self-consistent calculations of isoscalar giant monopole and quadrupole as well as isovector giant dipole resonances in heavy and light nuclei. The description is based on Skyrme energy-density functionals determining the static Hartree–Fock ground state and the excitation spectra within random-phase approximation (RPA and RPA extended by including the quasiparticle-phonon coupling at the level of the time-blocking approximation (TBA. All matrix elements were derived consistently from the given energy-density functional and calculated without any approximation. As a new feature in these calculations, the single-particle continuum was included thus avoiding the artificial discretization usually implied in RPA and TBA. The step to include phonon coupling in TBA leads to small, but systematic, down shifts of the centroid energies of the giant resonances. These shifts are similar in size for all Skyrme parametrizations investigated here. After all, we demonstrate that one can find Skyrme parametrizations which deliver a good simultaneous reproduction of all three giant resonances within TBA.

  7. Low-frequency RF Coupling To Unconventional (Fat Unbalanced) Dipoles

    Energy Technology Data Exchange (ETDEWEB)

    Ong, M M; Brown, C G; Perkins, M P; Speer, R D; Javedani, J B

    2010-12-07

    detonator bridge wire. This is called the common-mode voltage. The explosive component inside a detonator is relatively sensitive, and any electrical arc is a concern. In a safety analysis, the pin-to-cup voltage, i.e., detonator voltage, must be calculated to decide if an arc will form. If the electric field is known, the voltage between any two points is simply the integral of the field along a line between the points. Eq. 1.1. For simplicity, it is assumed that the electric field and dipole elements are aligned. Calculating the induced detonator voltage is more complex because of the field concentration caused by metal components. If the detonator cup is not electrically connected to the metal HE container, the portion of the voltage generated by the dipole at the detonator will divide between the container-to-cup and cup-to-pin gaps. The gap voltages are determined by their capacitances. As a simplification, it will be assumed the cup is electrically attached, short circuited, to the HE container. The electrical field in the pin-to-cup area is determined by the field near the dipole, the length of the dipole, the shape of the arms, and the orientation of the arms. Given the characteristics of a lightning strike and the inductance of the facility, the electric fields in the ''Faraday cage'' can be calculated. The important parameters for determining the voltage in an empty facility are the inductance of the rebars and the rate of change of the current, Eq. 1.3. The internal electric fields are directly related to the facility voltages, however, the electric fields in the pin-to-cup space is much higher than the facility fields because the antenna will concentrate the fields covered by the arms. Because the lightning current rise-time is different for every strike, the maximum electric field and the induced detonator voltage should be described by probability distributions. For pedantic purposes, the peak field in the simulations will be simply set to

  8. Nanoscale shift of the intensity distribution of dipole radiation.

    Science.gov (United States)

    Shu, Jie; Li, Xin; Arnoldus, Henk F

    2009-02-01

    The energy flow lines (field lines of the Poynting vector) for radiation emitted by a dipole are in general curves, rather than straight lines. For a linear dipole the field lines are straight, but when the dipole moment of a source rotates, the field lines wind numerous times around an axis, which is perpendicular to the plane of rotation, before asymptotically approaching a straight line. We consider an elliptical dipole moment, representing the most general state of oscillation, and this includes the linear dipole as a special case. Due to the spiraling near the source, for the case of a rotating dipole moment, the field lines in the far field are displaced with respect to the outward radial direction, and this leads to a shift of the intensity distribution of the radiation in the far field. This shift is shown to be independent of the distance to the source and, although of nanoscale dimension, should be experimentally observable.

  9. Amplitudes of solar-like oscillations in red giants: Departures from the quasi-adiabatic approximation

    Directory of Open Access Journals (Sweden)

    Barban C.

    2013-03-01

    Full Text Available CoRoT and Kepler measurements reveal us that the amplitudes of solar-like oscillations detected in red giant stars scale from stars to stars in a characteristic way. This observed scaling relation is not yet fully understood but constitutes potentially a powerful diagnostic about mode physics. Quasi-adiabatic theoretical scaling relations in terms of mode amplitudes result in systematic and large differences with the measurements performed for red giant stars. The use of a non-adiabatic intensity-velocity relation derived from a non-adiabatic pulsation code significantly reduces the discrepancy with the CoRoT measurements. The origin of the remaining difference is still unknown. Departure from adiabatic eigenfunction is a very likely explanation that is investigated in the present work using a 3D hydrodynamical model of the surface layers of a representative red giant star.

  10. Giant lipomas of the hand

    Directory of Open Access Journals (Sweden)

    Gokce Yildiran

    2015-04-01

    Conclusion: Giant lipomas of the hand are very rare and may cause compressions and other complications. Thus, they require a careful preoperative evaluation in order to make a proper differential diagnosis. [Hand Microsurg 2015; 4(1.000: 8-11

  11. Management of giant paraesophageal hernia.

    Science.gov (United States)

    Awais, O; Luketich, J D

    2009-04-01

    Management of giant paraesophageal hernia remains one of the most difficult challenges faced by surgeons treating complex benign esophageal disorders. These large hernias are acquired disorders; therefore, they invariably present in elderly patients. The dilemma that surgeons faced in the open surgical era was the risk of open surgery in this elderly, sick patient population versus the life threatening catastrophic complications, nearly 30% in some series, observed with medical management. During the 1990s, it was clearly recognized that laparoscopic surgery led to decreased morbidity with a quicker recovery. This has lead to a 6-fold increase in the surgical management of giant paraesophageal hernias over the last decade compared to a period of five decades of open surgery; however, this has not necessarily translated into better outcomes. One of the major issues with giant paraesophageal hernias is recognizing short esophagus and performing a lengthening procedure, if needed. Open series which report liberal use of Collis gastroplasty leading to a tension-free intraabdominal fundoplication have shown the best anatomic and clinical outcomes. As we duplicate the open experience laparoscopically, the principle of identifying a shortened esophagus and constructing a neo-esophagus must be honored for the success of the operation. The benefits of laparoscopy are obvious but should not come at the cost of a lesser operation. This review will illustrate that laparoscopic repair of giant paraesophageal hernia at experienced centers can be performed safely with similar outcomes to open series when the fundamental principles of the operation are maintained.

  12. A Giant or a Dwarf?

    DEFF Research Database (Denmark)

    Schmid, Herman

    2005-01-01

    EU may appear to be a giant when it can act on behalf of a united Europe, but usually it is hampered by conflicting member state interests. The EU economic and administrative resources for foreign and trade policy are quite small (on level with one of its major member states) and the hopes in many...

  13. 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.)

  14. Determination of giant resonance strengths

    International Nuclear Information System (INIS)

    Serr, F.E.

    1983-01-01

    Using theoretical strength functions to describe the different giant resonances expected at excitation energies of the order of (60-85)/Asup(1/3) MeV, we calculate the double differential cross sections d 2 sigma/dΩ dE associated with the reactions 208 Pb(α, α') and 90 Zr(α, α') (Esub(α) = 152 MeV). The angular distributions for the giant quadrupole and giant monopole resonances obtained from fits to these spectra, making simple, commonly used assumptions for the peak shapes and background, are compared to the original angular distributions. The differences between them are an indication of some of the uncertainties affecting the giant resonance strengths extracted from hadron inelastic scattering data. Fits to limited angular regions lead to errors of up to 50% in the value of the energy-weighted sum rule, depending on the angles examined. While it seems possible to extract the correct EWSR for the GMR by carrying out the analyses at 0 0 , no single privileged angle seems to exist in the case of the GQR. (orig.)

  15. Michigan has a sleeping giant

    CERN Multimedia

    Brock, Raymond; Nichols, Sue

    2007-01-01

    "That giant is 750 miles of fiber optic cable that lassoes its three biggest research universities and Van Andel Institute to the future. Its mission: to uncover the nature of the Big Bang by connecton U.S. physicists to their huge experiment ATLAS in Geneva.." (4 pages)

  16. Structure of dipole bands in 106In

    International Nuclear Information System (INIS)

    Deo, A. Y.; Palit, R.; Naik, Z.; Joshi, P. K.; Mazumdar, I.; Sihotra, S.; Mehta, D.; Kumar, S.; Chakrabarti, R.; Kshetri, R.; Jain, H. C.

    2009-01-01

    High spin states in neutron-deficient 106 In were investigated using 78 Se( 32 S,p3n) reaction at 125 MeV. The level scheme is extended up to 7 MeV of excitation energy for the negative parity states constituting four dipole bands, and the positive parity states which mainly exhibit single-particle excitations are extended up to 5 MeV. Projected deformed Hartree-Fock calculations were carried out to understand the configurations of different bands in this nucleus.

  17. Magnetic monopoles and dipoles in quantum mechanics

    International Nuclear Information System (INIS)

    Lipkin, H.J.; Peshkin, M.

    1986-01-01

    The force on and the energy of a ''di-monopole'', which is the limiting case of a dipole made from two monopoles at zero separation and finite magnetic moment, interacting with an externally fixed magnetic field resulting from an electric current, is considered. A model involving only a monopole is used to illustrate the physical principles involved when magnetic sources move in a solenoidal field whose source is an electric current. The problems encountered in Hamiltonian theory are discussed. 5 refs., 3 figs

  18. Directional Dipole Model for Subsurface Scattering

    DEFF Research Database (Denmark)

    Frisvad, Jeppe Revall; Hachisuka, Toshiya; Kjeldsen, Thomas Kim

    2014-01-01

    Rendering translucent materials using Monte Carlo ray tracing is computationally expensive due to a large number of subsurface scattering events. Faster approaches are based on analytical models derived from diffusion theory. While such analytical models are efficient, they miss out on some...... point source diffusion. A ray source corresponds better to the light that refracts through the surface of a translucent material. Using this ray source, we are able to take the direction of the incident light ray and the direction toward the point of emergence into account. We use a dipole construction...

  19. The AGL equation from the dipole picture

    International Nuclear Information System (INIS)

    Gay Ducati, M.B.; Goncalves, V.P.

    1999-01-01

    The AGL equation includes all multiple pomeron exchanges in the double logarithmic approximation (DLA) limit, leading to a unitarized gluon distribution in the small x regime. This equation was originally obtained using the Glauber-Mueller approach. We demonstrate in this paper that the AGL equation and, consequently, the GLR equation, can also be obtained from the dipole picture in the double logarithmic limit, using an evolution equation, recently proposed, which includes all multiple pomeron exchanges in the leading logarithmic approximation. Our conclusion is that the AGL equation is a good candidate for a unitarized evolution equation at small x in the DLA limit

  20. Effective gluon operators and neutron dipole moment

    International Nuclear Information System (INIS)

    Bigi, I.; Ural'tsev, N.G.

    1991-01-01

    The role of the purely gluon CP odd six-dimension effective arising in various CP-breaking models is discussed. This operators of most interest in the nonminimal Higgs sector models, the right W models and supersymmetric theories, where it may induce the neutron dipole moment at the level of the experimental restriction. The method for evaluating the magnitude d n is proposed and the reasons are given in favor that the original Weiberg's estimate based on the naive Dimensional Analysis is overdone significantly. The Peccei -Quinn mechanism, impact on the magnitude of d n , which generally may be very essential, is discussed

  1. Electric dipole moment of 3He

    International Nuclear Information System (INIS)

    Avishai, Y.; Fabre de la Ripelle, M.

    1986-01-01

    The contribution of a CP-nonconserving nucleon-nucleon interaction to the electric dipole moment of 3 He is evaluated in view of a recent proposal for its experimental detection. We use two models of CP-nonconserving interactions in combination with a Reid soft-core strong nucleon-nucleon interaction. In the Kobayashi-Maskawa model of CP nonconservation the order of magnitude is 10 -30 eX while the presence of the theta term in the QCD Langrangian contributes an order of magnitude 10 -16 theta-bar e cm

  2. The universal function in color dipole model

    Science.gov (United States)

    Jalilian, Z.; Boroun, G. R.

    2017-10-01

    In this work we review color dipole model and recall properties of the saturation and geometrical scaling in this model. Our primary aim is determining the exact universal function in terms of the introduced scaling variable in different distance than the saturation radius. With inserting the mass in calculation we compute numerically the contribution of heavy productions in small x from the total structure function by the fraction of universal functions and show the geometrical scaling is established due to our scaling variable in this study.

  3. Direct photons and dileptons via color dipoles

    International Nuclear Information System (INIS)

    Kopeliovich, B.Z.; Rezaeian, A.H.; Pirner, H.J.; Schmidt, Ivan

    2007-01-01

    Drell-Yan dilepton pair production and inclusive direct photon production can be described within a unified framework in the color dipole approach. The inclusion of non-perturbative primordial transverse momenta and DGLAP evolution is studied. We successfully describe data for dilepton spectra from 800-GeV pp collisions, inclusive direct photon spectra for pp collisions at RHIC energies √(s)=200 GeV, and for pp-bar collisions at tevatron energies √(s)=1.8 TeV, in a formalism that is free from any extra parameters

  4. Field simulations for large dipole magnets

    International Nuclear Information System (INIS)

    Lazzaro, A.; Cappuzzello, F.; Cunsolo, A.; Cavallaro, M.; Foti, A.; Khouaja, A.; Orrigo, S.E.A.; Winfield, J.S.

    2007-01-01

    The problem of the description of magnetic field for large bending magnets is addressed in relation to the requirements of modern techniques of trajectory reconstruction. The crucial question of the interpolation and extrapolation of fields known at a discrete number of points is analysed. For this purpose a realistic field model of the large dipole of the MAGNEX spectrometer, obtained with finite elements three dimensional simulations, is used. The influence of the uncertainties in the measured field to the quality of the trajectory reconstruction is treated in detail. General constraints for field measurements in terms of required resolutions, step sizes and precisions are thus extracted

  5. EDM: Neutron electric dipole moment measurement

    Directory of Open Access Journals (Sweden)

    Peter Fierlinger

    2016-02-01

    Full Text Available An electric dipole moment (EDM of the neutron would be a clear sign of new physics beyond the standard model of particle physics. The search for this phenomenon is considered one of the most important experiments in fundamental physics and could provide key information on the excess of matter versus antimatter in the universe. With high measurement precision, this experiment aims to ultimately achieve a sensitivity of 10-28 ecm, a 100-fold improvement in the sensitivity compared to the state-of-the-art. The EDM instrument is operated by an international collaboration based at the Technische Universität München.

  6. Neutron Electric Dipole Moment on the Lattice

    Science.gov (United States)

    Yoon, Boram; Bhattacharya, Tanmoy; Gupta, Rajan

    2018-03-01

    For the neutron to have an electric dipole moment (EDM), the theory of nature must have T, or equivalently CP, violation. Neutron EDM is a very good probe of novel CP violation in beyond the standard model physics. To leverage the connection between measured neutron EDM and novel mechanism of CP violation, one requires the calculation of matrix elements for CP violating operators, for which lattice QCD provides a first principle method. In this paper, we review the status of recent lattice QCD calculations of the contributions of the QCD Θ-term, the quark EDM term, and the quark chromo-EDM term to the neutron EDM.

  7. Neutron Electric Dipole Moment on the Lattice

    Directory of Open Access Journals (Sweden)

    Yoon Boram

    2018-01-01

    Full Text Available For the neutron to have an electric dipole moment (EDM, the theory of nature must have T, or equivalently CP, violation. Neutron EDM is a very good probe of novel CP violation in beyond the standard model physics. To leverage the connection between measured neutron EDM and novel mechanism of CP violation, one requires the calculation of matrix elements for CP violating operators, for which lattice QCD provides a first principle method. In this paper, we review the status of recent lattice QCD calculations of the contributions of the QCD Θ-term, the quark EDM term, and the quark chromo-EDM term to the neutron EDM.

  8. Electric Dipole Moments in Split Supersymmetry

    CERN Document Server

    Giudice, Gian Francesco

    2006-01-01

    We perform a quantitative study of the neutron and electron electric dipole moments (EDM) in Supersymmetry, in the limit of heavy scalars. The leading contributions arise at two loops. We give the complete analytic result, including a new contribution associated with Z-Higgs exchange, which plays an important and often leading role in the neutron EDM. The predictions for the EDM are typically within the sensitivities of the next generation experiments. We also analyse the correlation between the electron and neutron EDM, which provides a robust test of Split Supersymmetry.

  9. Prototype steel-concrete LEP dipole magnet

    CERN Multimedia

    1981-01-01

    The magnetic field needed in the LEP dipole magnets was rather low, of a fraction of tesla. This lead to the conception of a novel yoke structure consisting of stacks of 1.5 mm thick low-carbon steel laminations spaced by 4.1 mm with the spaces filled with concrete. The excitation coils were also very simple: aluminium bars insulated by polyester boxes in this prototype, by glass-epoxy in the final magnets. For details see LEP-Note 118,1978 and LEP-Note 233 1980. See also 8111529,7908528X.

  10. Strong CP violation and the neutron electric dipole form factor

    International Nuclear Information System (INIS)

    Kuckei, J.; Dib, C.; Faessler, A.; Gutsche, T.; Kovalenko, S. G.; Lyubovitskij, V. E.; Pumsa-ard, K.

    2007-01-01

    We calculate the neutron electric dipole form factor induced by the CP-violating θ term of QCD within a perturbative chiral quark model which includes pion and kaon clouds. On this basis, we derive the neutron electric dipole moment and the electron-neutron Schiff moment. From the existing experimental upper limits on the neutron electric dipole moment, we extract constraints on the θ parameter and compare our results with other approaches

  11. An effective field theory for the neutron electric dipole moment

    International Nuclear Information System (INIS)

    Chang, D.; Kephart, T.W.; Keung, W.Y.; Yuan, T.C.

    1992-01-01

    We derive a CP-odd effective field theory involving the field strengths of the gluon and the photon and their duals as a result of integrating out a heavy quark which carries both the chromo-electric dipole moment and electric dipole moment. The coefficients of the induced gluonic, photonic, and mixed gluon-photon operators with dimension ≤ 8 are determined. Implications of some of these operators on the neutron electric dipole moment are also discussed. (orig.)

  12. Electric Dipole Antenna: A Source of Gravitational Radiation

    Directory of Open Access Journals (Sweden)

    Chifu E. N.

    2013-07-01

    Full Text Available In this article, the gravitational scalar potential due to an oscillating electric dipole antenna placed in empty space is derived. The gravitational potential obtained propagates as a wave. The gravitational waves have phase velocity equal to the speed of light in vacuum (c at the equatorial plane of the electric dipole antenna, unlike electromagnetic waves from the dipole antenna that cancel out at the equatorial plane due to charge symmetry.

  13. Electric-dipole-induced universality for Dirac fermions in graphene.

    Science.gov (United States)

    De Martino, Alessandro; Klöpfer, Denis; Matrasulov, Davron; Egger, Reinhold

    2014-05-09

    We study electric dipole effects for massive Dirac fermions in graphene and related materials. The dipole potential accommodates towers of infinitely many bound states exhibiting a universal Efimov-like scaling hierarchy. The dipole moment determines the number of towers, but there is always at least one tower. The corresponding eigenstates show a characteristic angular asymmetry, observable in tunnel spectroscopy. However, charge transport properties inferred from scattering states are highly isotropic.

  14. Angle-dependent quantum Otto heat engine based on coherent dipole-dipole coupling

    Science.gov (United States)

    Su, Shan-He; Luo, Xiao-Qing; Chen, Jin-Can; Sun, Chang-Pu

    2016-08-01

    Electromagnetic interactions between molecules or within a molecule have been widely observed in biological systems and exhibit broad application for molecular structural studies. Quantum delocalization of molecular dipole moments has inspired researchers to explore new avenues to utilize this physical effect for energy harvesting devices. Herein, we propose a simple model of the angle-dependent quantum Otto heat engine which seeks to facilitate the conversion of heat to work. Unlike previous studies, the adiabatic processes are accomplished by varying only the directions of the magnetic field. We show that the heat engine continues to generate power when the angle relative to the vector r joining the centres of coupled dipoles departs from the magic angle θm where the static coupling vanishes. A significant improvement in the device performance has to be attributed to the presence of the quantum delocalized levels associated with the coherent dipole-dipole coupling. These results obtained may provide a promising model for the biomimetic design and fabrication of quantum energy generators.

  15. Induced dipole-dipole coupling between two atoms at a migration resonance

    Science.gov (United States)

    Kaur, Maninder; Mian, Mahmood

    2018-05-01

    Results of numerical simulations for the resonant energy exchange phenomenon called Migration reaction between two cold Rydberg atoms are presented. The effect of spatial interatomic distance on the onset of peculiar coherent mechanism is investigated. Observation of Rabi-like population inversion oscillation at the resonance provides a clear signature of dipole induced exchange of electronic excitations between the atoms. Further we present the results for the dependence of expectation value of the interaction hamiltonian on the interatomic distance, which is responsible for energy exchange process. The results of this observation endorse the range of inter atomic distance within which the excitation exchange process occurs completely or partially. Migration process enhance the Rydberg-Rydberg interaction in the absence of an external field, under the condition of the zero permanent dipole moments. Our next observation sheds light on the fundamental mechanism of induced electric fields initiated by the oscillating dipoles in such energy exchange processes. We explore the dependence of induced electric field on the interatomic distance and angle between the dipoles highlighting the inverse power law dependence and anisotropic property of the field. We put forward an idea to utilise the coherent energy exchange process to build efficient and fast energy transfer channels by incorporating more atoms organised at successive distances with decreasing distance gradient.

  16. Giant hydronephrosis mimicking progressive malignancy

    Science.gov (United States)

    Schrader, Andres Jan; Anderer, Georgia; von Knobloch, Rolf; Heidenreich, Axel; Hofmann, Rainer

    2003-01-01

    Background Cases of giant hydronephroses are rare and usually contain no more than 1–2 litres of fluid in the collecting system. We report a remarkable case of giant hydronephrosis mimicking a progressive malignant abdominal tumour. Case presentation A 78-year-old cachectic woman presented with an enormous abdominal tumour, which, according to the patient, had slowly increased in diameter. Medical history was unremarkable except for a hysterectomy >30 years before. A CT scan revealed a giant cystic tumour filling almost the entire abdominal cavity. It was analysed by two independent radiologists who suspected a tumour originating from the right kidney and additionally a cystic ovarian neoplasm. Subsequently, a diagnostic and therapeutic laparotomy was performed: the tumour presented as a cystic, 35 × 30 × 25 cm expansive structure adhesive to adjacent organs without definite signs of invasive growth. The right renal hilar vessels could finally be identified at its basis. After extirpation another tumourous structure emerged in the pelvis originating from the genital organs and was also resected. The histopathological examination revealed a >15 kg hydronephrotic right kidney, lacking hardly any residual renal cortex parenchyma. The second specimen was identified as an ovary with regressive changes and a large partially calcified cyst. There was no evidence of malignant growth. Conclusion Although both clinical symptoms and the enormous size of the tumour indicated malignant growth, it turned out to be a giant hydronephrosis. Presumably, a chronic obstruction of the distal ureter had caused this extraordinary hydronephrosis. As demonstrated in our case, an accurate diagnosis of giant hydronephrosis remains challenging due to the atrophy of the renal parenchyma associated with chronic obstruction. Therefore, any abdominal cystic mass even in the absence of other evident pathologies should include the differential diagnosis of a possible hydronephrosis. Diagnostic

  17. Enhanced terahertz magnetic dipole response by subwavelength fiber

    DEFF Research Database (Denmark)

    Atakaramians, Shaghik; Shadrivov, Ilya V.; Miroshnichenko, Andrey E.

    2018-01-01

    Dielectric sub-wavelength particles have opened up a new platform for realization of magnetic light. Recently, we have demonstrated that a dipole emitter by a sub-wavelength fiber leads to an enhanced magnetic response. Here, we experimentally demonstrate an enhanced magnetic dipole source......-fiber system excited by a magnetic source. This coupled magnetic dipole and optical fiber system can be considered a unit cell of metasurfaces for manipulation of terahertz radiation and is a proof-of-concept of a possibility to achieve enhanced radiation of a dipole source in proximity of a sub...

  18. Measurement of the b hadron lifetime with the dipole method

    Science.gov (United States)

    Buskulic, D.; de Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J.-P.; Minard, M.-N.; Pietrzyk, B.; Ariztizabal, F.; Comas, P.; Crespo, J. M.; Delfino, M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Gaitan, V.; Garrido, Ll.; Mattison, T.; Pacheco, A.; Padilla, C.; Pascual, A.; Creanza, D.; de Palma, M.; Farilla, A.; Iaselli, G.; Maggi, G.; Marinelli, N.; Natali, S.; Nuzzo, S.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Chai, Y.; Hu, H.; Huang, D.; Huang, X.; Lin, J.; Wang, T.; Xie, Y.; Xu, D.; Xu, R.; Zhang, J.; Zhang, L.; Zhao, W.; Bonvicini, G.; Boudreau, J.; Casper, D.; Drevermann, H.; Forty, R. W.; Ganis, G.; Gay, C.; Hagelberg, R.; Harvey, J.; Hilgart, J.; Jacobsen, R.; Jost, B.; Knobloch, J.; Lehraus, I.; Maggi, M.; Markou, C.; Martinez, M.; Mato, P.; Meinhard, H.; Minten, A.; Miquel, R.; Moser, H.-G.; Palazzi, P.; Pater, J. R.; Perlas, J. A.; Pusztaszeri, J.-F.; Ranjard, F.; Rolandi, L.; Rothberg, J.; Ruan, T.; Saich, M.; Schlatter, D.; Schmelling, M.; Sefkow, F.; Tejessy, W.; Tomalin, I. R.; Veenhof, R.; Wachsmuth, H.; Wasserbaech, S.; Wiedenmann, W.; Wildish, T.; Witzeling, W.; Wotschack, J.; Ajaltouni, Z.; Badaud, F.; Bardadin-Otwinowska, M.; El Fellous, R.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Prulhière, F.; Saadi, F.; Fearnley, T.; Hansen, J. B.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Møllerud, R.; Nilsson, B. S.; Kyriakis, A.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Zachariadou, K.; Badier, J.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Bourdon, P.; Fouque, G.; Orteu, S.; Rougé, A.; Rumpf, M.; Tanaka, R.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Veitch, E.; Focardi, E.; Moneta, L.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Ikeda, M.; Levinthal, D.; Antonelli, A.; Baldini, R.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Cerutti, F.; Chiarella, V.; D'Ettorre-Piazzoli, B.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Picchi, P.; Colrain, P.; Ten Have, I.; Lynch, J. G.; Maitland, W.; Morton, W. T.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Smith, M. G.; Thompson, A. S.; Turnbull, R. M.; Brandl, B.; Braun, O.; Geweniger, C.; Hanke, P.; Hepp, V.; Kluge, E. E.; Maumary, Y.; Putzer, A.; Rensch, B.; Stahl, A.; Tittel, K.; Wunsch, M.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Cattaneo, M.; Colling, D. J.; Dornan, P. J.; Greene, A. M.; Hassard, J. F.; Lieske, N. M.; Moutoussi, A.; Nash, J.; Patton, S.; Payne, D. G.; Phillips, M. J.; San Martin, G.; Sedgbeer, J. K.; Wright, A. G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Vogl, R.; Bowdery, C. K.; Brodbeck, T. J.; Finch, A. J.; Foster, F.; Hughes, G.; Jackson, D.; Keemer, N. R.; Nuttall, M.; Patel, A.; Sloan, T.; Snow, S. W.; Whelan, E. P.; Kleinknecht, K.; Raab, J.; Renk, B.; Sander, H.-G.; Schmidt, H.; Walther, S. M.; Wanke, R.; Wolf, B.; Zimmermann, A.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Carr, J.; Coyle, P.; Drinkard, J.; Etienne, F.; Nicod, D.; Papalexiou, S.; Payre, P.; Roos, L.; Rousseau, D.; Schwemling, P.; Talby, M.; Adlung, S.; Assmann, R.; Bauer, C.; Blum, W.; Brown, D.; Cattaneo, P.; Dehning, B.; Dietl, H.; Dydak, F.; Frank, M.; Halley, A. W.; Jakobs, K.; Lauber, J.; Lütjens, G.; Lutz, G.; Männer, W.; Richter, R.; Schröder, J.; Schwarz, A. S.; Settles, R.; Seywerd, H.; Stierlin, U.; Stiegler, U.; St. Denis, R.; Wolf, G.; Alemany, R.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Jaffe, D. E.; Janot, P.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Schune, M.-H.; Veillet, J.-J.; Videau, I.; Zhang, Z.; Abbaneo, D.; Bagliesi, G.; Batignani, G.; Bottigli, U.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Ciulli, V.; Dell'Orso, R.; Ferrante, I.; Fidecaro, F.; Foà, L.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Mannelli, E. B.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Triggiani, G.; Valassi, A.; Vannini, C.; Venturi, A.; Verdini, P. G.; Walsh, J.; Betteridge, A. P.; Gao, Y.; Green, M. G.; March, P. V.; Mir, Ll. M.; Medcalf, T.; Quazi, I. S.; Strong, J. A.; West, L. R.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Haywood, S.; Norton, P. R.; Thompson, J. C.; Bloch-Devaux, B.; Colas, P.; Duarte, H.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J.-F.; Rosowsky, A.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Si Mohand, D.; Vallage, B.; Johnson, R. P.; Litke, A. M.; Taylor, G.; Wear, J.; Ashman, J. G.; Babbage, W.; Booth, C. N.; Buttar, C.; Cartwright, S.; Combley, F.; Dawson, I.; Thompson, L. F.; Barbeiro, E.; Böhrer, A.; Brandt, S.; Cowan, G.; Grupen, C.; Lutters, G.; Rivera, F.; Schäfer, U.; Smolik, L.; Bosisio, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Ragusa, F.; Bellantoni, L.; Chen, W.; Conway, J. S.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; Grahl, J.; Harton, J. L.; Hayes, O. J.; Nachtman, J. M.; Pan, Y. B.; Saadi, Y.; Schmitt, M.; Scott, I.; Sharma, V.; Shi, Z. H.; Turk, J. D.; Walsh, A. M.; Weber, F. V.; Sau Lan Wu; Wu, X.; Zheng, M.; Zobernig, G.; Aleph Collaboration

    1993-09-01

    A measurement of the average lifetime of b hadrons has been performed with dipole method on a sample of 260 000 hadronic Z decays recorded with the ALEPH detector during 1991. The dipole is the distance between the vertices built in the opposite hemispheres. The mean dipole is extracted from all the events without attempting b enrichment. Comparing the average of the data dipole distribution with a Monte Carlo calibration curve obtained with different b lifetimes, an average b hadron lifetime of 1.51±0.08 ps is extracted.

  19. The neutron electric dipole moment and the Weinberg's operator

    International Nuclear Information System (INIS)

    Li Chongsheng; Hu Bingquan

    1992-01-01

    After a summary of the predictions for the neutron electric dipole moment in a number of models of CP violation, the authors review mainly the recent developments associated with Weimberg's purely gluonic CP violation operator. Its implications on the neutron electric dipole moment in various models of CP violation are discussed. Inspired by Weimberg's work, several new mechanisms of generating large electric dipole moments of charged leptons and large electric and chromo-electric dipole moments of light quarks are recently proposed. Brief discussions on these new developments are also given

  20. Dipole moments of molecules solvated in helium nanodroplets

    International Nuclear Information System (INIS)

    Stiles, Paul L.; Nauta, Klaas; Miller, Roger E.

    2003-01-01

    Stark spectra are reported for hydrogen cyanide and cyanoacetylene solvated in helium nanodroplets. The goal of this study is to understand the influence of the helium solvent on measurements of the permanent electric dipole moment of a molecule. We find that the dipole moments of the helium solvated molecules, calculated assuming the electric field is the same as in vacuum, are slightly smaller than the well-known gas-phase dipole moments of HCN and HCCCN. A simple elliptical cavity model quantitatively accounts for this difference, which arises from the dipole-induced polarization of the helium