WorldWideScience

Sample records for strong dipole source

  1. Oscillating molecular dipoles require strongly correlated electronic and nuclear motion

    International Nuclear Information System (INIS)

    Chang, Bo Y; Shin, Seokmin; Palacios, Alicia; Martín, Fernando; Sola, Ignacio R

    2015-01-01

    To create an oscillating electric dipole in an homonuclear diatomic cation without an oscillating driver one needs (i) to break the symmetry of the system and (ii) to sustain highly correlated electronic and nuclear motion. Based on numerical simulations in H 2 + we present results for two schemes. In the first one (i) is achieved by creating a superposition of symmetric and antisymmetric electronic states freely evolving, while (ii) fails. In a second scheme, by preparing the system in a dressed state of a strong static field, both conditions hold. We then analyze the robustness of this scheme with respect to features of the nuclear wave function and its intrinsic sources of decoherence. (tutorial)

  2. Atom-Pair Kinetics with Strong Electric-Dipole Interactions.

    Science.gov (United States)

    Thaicharoen, N; Gonçalves, L F; Raithel, G

    2016-05-27

    Rydberg-atom ensembles are switched from a weakly to a strongly interacting regime via adiabatic transformation of the atoms from an approximately nonpolar into a highly dipolar quantum state. The resultant electric dipole-dipole forces are probed using a device akin to a field ion microscope. Ion imaging and pair-correlation analysis reveal the kinetics of the interacting atoms. Dumbbell-shaped pair-correlation images demonstrate the anisotropy of the binary dipolar force. The dipolar C_{3} coefficient, derived from the time dependence of the images, agrees with the value calculated from the permanent electric-dipole moment of the atoms. The results indicate many-body dynamics akin to disorder-induced heating in strongly coupled particle systems.

  3. 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

  4. Lepton electric dipole moment and strong CP violation

    Science.gov (United States)

    Ghosh, Diptimoy; Sato, Ryosuke

    2018-02-01

    Contribution of the strong CP angle, θ bar , to the Wilson Coefficients of electron and muon electric dipole moment (EDM) operators are discussed. Previously, θ bar contribution to the electron EDM operator was calculated by Choi and Hong [1]. However, the effect of CP-violating three meson coupling was missing in [1]. We include this missing contribution for the first time in the literature, and reevaluate the Wilson coefficients of the lepton EDM operator. We obtain de = - (2.2 - 8.6) ×10-28 θ bar e-cm which is 15-70% of the result obtained in [1]. We also estimated the muon EDM as dμ = - (0.5 - 1.8) ×10-25 θ bar e-cm. Using | θ bar | ≲10-10 suggested by the neutron EDM measurements, we obtain |de | ≲ 8.6 ×10-38e-cm and |dμ | ≲ 1.8 ×10-35e-cm. The θ bar contribution to the muon EDM is much below the sensitivities of the current and near future experiments. Our result shows that the θ bar contribution to de,μ can be larger than the CKM contributions by many orders of magnitude.

  5. Lepton electric dipole moment and strong CP violation

    Directory of Open Access Journals (Sweden)

    Diptimoy Ghosh

    2018-02-01

    Full Text Available Contribution of the strong CP angle, θ¯, to the Wilson Coefficients of electron and muon electric dipole moment (EDM operators are discussed. Previously, θ¯ contribution to the electron EDM operator was calculated by Choi and Hong [1]. However, the effect of CP-violating three meson coupling was missing in [1]. We include this missing contribution for the first time in the literature, and reevaluate the Wilson coefficients of the lepton EDM operator. We obtain de=−(2.2–8.6×10−28θ¯e-cm which is 15–70% of the result obtained in [1]. We also estimated the muon EDM as dμ=−(0.5–1.8×10−25θ¯e-cm. Using |θ¯|≲10−10 suggested by the neutron EDM measurements, we obtain |de|≲8.6×10−38e-cm and |dμ|≲1.8×10−35e-cm. The θ¯ contribution to the muon EDM is much below the sensitivities of the current and near future experiments. Our result shows that the θ¯ contribution to de,μ can be larger than the CKM contributions by many orders of magnitude.

  6. Strong electric and magnetic dipole excitations in deformed nuclei

    International Nuclear Information System (INIS)

    Kneissl, U.

    1993-01-01

    Systematic nuclear resonance fluorescence (NRF) experiments have been performed at the bremsstrahlung facility of the Stutgart dynamitron to investigate the distribution of magnetic and electric dipole excitations in deformed nuclei

  7. Stacked dipole line source excitation of active nano-particles

    DEFF Research Database (Denmark)

    Arslanagic, Samel

    This work investigates electromagnetic properties of cylindrical active coated nano-particles excited by a stac- ked electric dipole line source. The nano-particles consist of a silica nano-core, layered by silver, gold, or copper nano-shell. Attention is devoted to the influence of the source...... location and dipole orientation, the gain constant, and the nano-particle material composition on the electromagnetic field distributions and radiated powers. The results are contrasted to those for the magnetic line source illumination of the nano-particles....

  8. Strong dependence of ultracold chemical rates on electric dipole moments

    International Nuclear Information System (INIS)

    Quemener, Goulven; Bohn, John L.

    2010-01-01

    We use the quantum threshold laws combined with a classical capture model to provide an analytical estimate of the chemical quenching cross sections and rate coefficients of two colliding particles at ultralow temperatures. We apply this quantum threshold model (QT model) to indistinguishable fermionic polar molecules in an electric field. At ultracold temperatures and in weak electric fields, the cross sections and rate coefficients depend only weakly on the electric dipole moment d induced by the electric field. In stronger electric fields, the quenching processes scale as d 4(L+(1/2)) where L>0 is the orbital angular-momentum quantum number between the two colliding particles. For p-wave collisions (L=1) of indistinguishable fermionic polar molecules at ultracold temperatures, the quenching rate thus scales as d 6 . We also apply this model to pure two-dimensional collisions and find that chemical rates vanish as d -4 for ultracold indistinguishable fermions. This model provides a quick and intuitive way to estimate chemical rate coefficients of reactions occuring with high probability.

  9. An alternative subspace approach to EEG dipole source localization

    Science.gov (United States)

    Xu, Xiao-Liang; Xu, Bobby; He, Bin

    2004-01-01

    In the present study, we investigate a new approach to electroencephalography (EEG) three-dimensional (3D) dipole source localization by using a non-recursive subspace algorithm called FINES. In estimating source dipole locations, the present approach employs projections onto a subspace spanned by a small set of particular vectors (FINES vector set) in the estimated noise-only subspace instead of the entire estimated noise-only subspace in the case of classic MUSIC. The subspace spanned by this vector set is, in the sense of principal angle, closest to the subspace spanned by the array manifold associated with a particular brain region. By incorporating knowledge of the array manifold in identifying FINES vector sets in the estimated noise-only subspace for different brain regions, the present approach is able to estimate sources with enhanced accuracy and spatial resolution, thus enhancing the capability of resolving closely spaced sources and reducing estimation errors. The present computer simulations show, in EEG 3D dipole source localization, that compared to classic MUSIC, FINES has (1) better resolvability of two closely spaced dipolar sources and (2) better estimation accuracy of source locations. In comparison with RAP-MUSIC, FINES' performance is also better for the cases studied when the noise level is high and/or correlations among dipole sources exist.

  10. An alternative subspace approach to EEG dipole source localization

    International Nuclear Information System (INIS)

    Xu Xiaoliang; Xu, Bobby; He Bin

    2004-01-01

    In the present study, we investigate a new approach to electroencephalography (EEG) three-dimensional (3D) dipole source localization by using a non-recursive subspace algorithm called FINES. In estimating source dipole locations, the present approach employs projections onto a subspace spanned by a small set of particular vectors (FINES vector set) in the estimated noise-only subspace instead of the entire estimated noise-only subspace in the case of classic MUSIC. The subspace spanned by this vector set is, in the sense of principal angle, closest to the subspace spanned by the array manifold associated with a particular brain region. By incorporating knowledge of the array manifold in identifying FINES vector sets in the estimated noise-only subspace for different brain regions, the present approach is able to estimate sources with enhanced accuracy and spatial resolution, thus enhancing the capability of resolving closely spaced sources and reducing estimation errors. The present computer simulations show, in EEG 3D dipole source localization, that compared to classic MUSIC, FINES has (1) better resolvability of two closely spaced dipolar sources and (2) better estimation accuracy of source locations. In comparison with RAP-MUSIC, FINES' performance is also better for the cases studied when the noise level is high and/or correlations among dipole sources exist

  11. Permanent magnet based dipole magnets for next generation light sources

    Directory of Open Access Journals (Sweden)

    Takahiro Watanabe

    2017-07-01

    Full Text Available We have developed permanent magnet based dipole magnets for the next generation light sources. Permanent magnets are advantageous over electromagnets in that they consume less power, are physically more compact, and there is a less risk of power supply failure. However, experience with electromagnets and permanent magnets in the field of accelerators shows that there are still challenges to replacing main magnets of accelerators for light sources with permanent magnets. These include the adjustability of the magnetic field, the temperature dependence of permanent magnets, and the issue of demagnetization. In this paper, we present a design for magnets for future light sources, supported by experimental and numerical results.

  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. Dipole power supply for National Synchrotron Light Source Booster upgrade

    International Nuclear Information System (INIS)

    Olsen, R.; Dabrowski, J.; Murray, J.

    1992-01-01

    The booster at the NSLS is being upgraded from .75 to 2 pulses per second. To accomplish this, new power supplies for the dipole, quadrupole, and sextupole magnets have been designed and are being constructed. This paper will outline the design of the dipole power supply and control system, and will present results obtained thus far

  14. Characterization of strong (241)Am sources.

    Science.gov (United States)

    Vesterlund, Anna; Chernikova, Dina; Cartemo, Petty; Axell, Kåre; Nordlund, Anders; Skarnemark, Gunnar; Ekberg, Christian; Ramebäck, Henrik

    2015-05-01

    Gamma ray spectra of strong (241)Am sources may reveal information about the source composition as there may be other radioactive nuclides such as progeny and radioactive impurities present. In this work the possibility to use gamma spectrometry to identify inherent signatures in (241)Am sources in order to differentiate sources from each other, is investigated. The studied signatures are age, i.e. time passed since last chemical separation, and presence of impurities. The spectra of some sources show a number of Doppler broadened peaks in the spectrum which indicate the presence of nuclear reactions on light elements within the sources. The results show that the investigated sources can be differentiated between by age and/or presence of impurities. These spectral features would be useful information in a national nuclear forensics library (NNFL) in cases when the visual information on the source, e.g. the source number, is unavailable. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Tracking single dynamic MEG dipole sources using the projected Extended Kalman Filter.

    Science.gov (United States)

    Yao, Yuchen; Swindlehurst, A Lee

    2011-01-01

    This paper presents two new algorithms based on the Extended Kalman Filter (EKF) for tracking the parameters of single dynamic magnetoencephalography (MEG) dipole sources. We assume a dynamic MEG dipole source with possibly both time-varying location and dipole orientation. The standard EKF-based tracking algorithm performs well under the assumption that the dipole source components vary in time as a Gauss-Markov process, provided that the background noise is temporally stationary. We propose a Projected-EKF algorithm that is adapted to a more forgiving condition where the background noise is temporally nonstationary, as well as a Projected-GLS-EKF algorithm that works even more universally, when the dipole components vary arbitrarily from one sample to the next.

  16. Effect of dipole polarizability on positron binding by strongly polar molecules

    International Nuclear Information System (INIS)

    Gribakin, G F; Swann, A R

    2015-01-01

    A model for positron binding to polar molecules is considered by combining the dipole potential outside the molecule with a strongly repulsive core of a given radius. Using existing experimental data on binding energies leads to unphysically small core radii for all of the molecules studied. This suggests that electron–positron correlations neglected in the simple model play a large role in determining the binding energy. We account for these by including the polarization potential via perturbation theory and non-perturbatively. The perturbative model makes reliable predictions of binding energies for a range of polar organic molecules and hydrogen cyanide. The model also agrees with the linear dependence of the binding energies on the polarizability inferred from the experimental data (Danielson et al 2009 J. Phys. B: At. Mol. Opt. Phys. 42 235203). The effective core radii, however, remain unphysically small for most molecules. Treating molecular polarization non-perturbatively leads to physically meaningful core radii for all of the molecules studied and enables even more accurate predictions of binding energies to be made for nearly all of the molecules considered. (paper)

  17. Cosmogenic photons strongly constrain UHECR source models

    Directory of Open Access Journals (Sweden)

    van Vliet Arjen

    2017-01-01

    Full Text Available With the newest version of our Monte Carlo code for ultra-high-energy cosmic ray (UHECR propagation, CRPropa 3, the flux of neutrinos and photons due to interactions of UHECRs with extragalactic background light can be predicted. Together with the recently updated data for the isotropic diffuse gamma-ray background (IGRB by Fermi LAT, it is now possible to severely constrain UHECR source models. The evolution of the UHECR sources especially plays an important role in the determination of the expected secondary photon spectrum. Pure proton UHECR models are already strongly constrained, primarily by the highest energy bins of Fermi LAT’s IGRB, as long as their number density is not strongly peaked at recent times.

  18. Calorimetric measurement of strong γ emitting sources

    International Nuclear Information System (INIS)

    Brangier, B.; Herczeg, C.; Henry, R.

    1968-01-01

    This publication gives the principle and a description of an adiabatic calorimeter for measuring the real activity of strong gamma-emitting sources by absorbing the emitted energy in a mass of copper. Because of the difficulty of evaluating the amount self- absorption, we have built a calorimeter for measuring the self- absorption, and a description of it is given.The results of these three measurements are fairly satisfactory. The calibration and the actual measurements obtained are given with a few corrections made necessary by the design of the apparatus. The correlation of the various results is discussed. (author) [fr

  19. Comparison of the electronic structure of two polymers with strong dipole ordering

    International Nuclear Information System (INIS)

    Xiao Jie; Rosa, Luis G; Poulsen, Matt; Feng, D-Q; Reddy, D Sahadeva; Takacs, James M; Cai, Lei; Zhang, Jiandi; Ducharme, Stephen; Dowben, P A

    2006-01-01

    Two different polymers, with large local electric dipoles, are compared: copolymers of polyvinylidene fluoride with trifluoroethylene [P(VDF-TrFE, 70%:30%)] and polymethylvinylidenecyanide (PMVC). While the different local point group symmetries play a key role, both crystalline polymers exhibit intra-molecular band structure, though the Brillouin zone critical points differ. (letter to the editor)

  20. Anatomically constrained dipole adjustment (ANACONDA) for accurate MEG/EEG focal source localizations

    Science.gov (United States)

    Im, Chang-Hwan; Jung, Hyun-Kyo; Fujimaki, Norio

    2005-10-01

    This paper proposes an alternative approach to enhance localization accuracy of MEG and EEG focal sources. The proposed approach assumes anatomically constrained spatio-temporal dipoles, initial positions of which are estimated from local peak positions of distributed sources obtained from a pre-execution of distributed source reconstruction. The positions of the dipoles are then adjusted on the cortical surface using a novel updating scheme named cortical surface scanning. The proposed approach has many advantages over the conventional ones: (1) as the cortical surface scanning algorithm uses spatio-temporal dipoles, it is robust with respect to noise; (2) it requires no a priori information on the numbers and initial locations of the activations; (3) as the locations of dipoles are restricted only on a tessellated cortical surface, it is physiologically more plausible than the conventional ECD model. To verify the proposed approach, it was applied to several realistic MEG/EEG simulations and practical experiments. From the several case studies, it is concluded that the anatomically constrained dipole adjustment (ANACONDA) approach will be a very promising technique to enhance accuracy of focal source localization which is essential in many clinical and neurological applications of MEG and EEG.

  1. Anatomically constrained dipole adjustment (ANACONDA) for accurate MEG/EEG focal source localizations

    International Nuclear Information System (INIS)

    Im, Chang-Hwan; Jung, Hyun-Kyo; Fujimaki, Norio

    2005-01-01

    This paper proposes an alternative approach to enhance localization accuracy of MEG and EEG focal sources. The proposed approach assumes anatomically constrained spatio-temporal dipoles, initial positions of which are estimated from local peak positions of distributed sources obtained from a pre-execution of distributed source reconstruction. The positions of the dipoles are then adjusted on the cortical surface using a novel updating scheme named cortical surface scanning. The proposed approach has many advantages over the conventional ones: (1) as the cortical surface scanning algorithm uses spatio-temporal dipoles, it is robust with respect to noise; (2) it requires no a priori information on the numbers and initial locations of the activations; (3) as the locations of dipoles are restricted only on a tessellated cortical surface, it is physiologically more plausible than the conventional ECD model. To verify the proposed approach, it was applied to several realistic MEG/EEG simulations and practical experiments. From the several case studies, it is concluded that the anatomically constrained dipole adjustment (ANACONDA) approach will be a very promising technique to enhance accuracy of focal source localization which is essential in many clinical and neurological applications of MEG and EEG

  2. Measurement of dipole-moment in atomic transitions under strong external magnetic field

    International Nuclear Information System (INIS)

    Nittoh, Koichi; Kuwako, Akira; Ikehara, Tadashi; Yoshida, Tadashi; Watanabe, Takasi; Yoguchi, Itaru; Suzuki, Kazuhiro.

    1996-01-01

    Obtaining an accurate value of the electric dipole moment μ is essential in the fields of laser application technologies. A direct way of measuring the electric dipole moment μ is to observe the Rabi-oscillation which manifests itself in the coherent photo-excitation behavior of atoms. In the case of the elements which have large angular momenta, identifying the Rabi-oscillation in their excitation behavior becomes rather difficult. We proposed an accurate and straightforward method of determining the electric-dipole moment μ between multi-fold degenerate levels. The point is to remove the degeneracy by applying an external magnetic field with the aid of the Zeeman effect and, then, to realize a degeneration free coherent excitation. As a result, we can observe the Rabi-oscillations explicitly in the excitation υs. laser-fluence curves. The present method provides a reliable basis of experimental determination of μ. As an example, we applied the present method to a transition to 0-17,362 cm -1 level in uranium and obtained the value μ=0.86±0.06 (Debye). (author)

  3. Source localization using a non-cocentered orthogonal loop and dipole (NCOLD) array

    Institute of Scientific and Technical Information of China (English)

    Liu Zhaoting; Xu Tongyang

    2013-01-01

    A uniform array of scalar-sensors with intersensor spacings over a large aperture size generally offers enhanced resolution and source localization accuracy, but it may also lead to cyclic ambiguity. By exploiting the polarization information of impinging waves, an electromagnetic vec-tor-sensor array outperforms the unpolarized scalar-sensor array in resolving this cyclic ambiguity. However, the electromagnetic vector-sensor array usually consists of cocentered orthogonal loops and dipoles (COLD), which is easily subjected to mutual coupling across these cocentered dipoles/loops. As a result, the source localization performance of the COLD array may substantially degrade rather than being improved. This paper proposes a new source localization method with a non-cocentered orthogonal loop and dipole (NCOLD) array. The NCOLD array contains only one dipole or loop on each array grid, and the intersensor spacings are larger than a half-wave-length. Therefore, unlike the COLD array, these well separated dipoles/loops minimize the mutual coupling effects and extend the spatial aperture as well. With the NCOLD array, the proposed method can efficiently exploit the polarization information to offer high localization precision.

  4. Artificial lateral-line system for imaging dipole sources using Beamforming techniques

    NARCIS (Netherlands)

    Dagamseh, A.M.K.; Wiegerink, Remco J.; Lammerink, Theodorus S.J.; Krijnen, Gijsbertus J.M.

    In nature, fish have the ability to localize prey, school, navigate, etc. using the lateral-line organ [1]. Here we present the use of biomimetic artificial hair-based flow-sensors arranged as lateral-line system in combination with beamforming techniques for dipole source localization in air.

  5. Motion of Rydberg atoms with strong permanent-electric-dipole interactions

    International Nuclear Information System (INIS)

    Gonçalves, Luís Felipe; Thaicharoen, Nithiwadee; Raithel, Georg

    2016-01-01

    Using classical trajectories simulations, we investigate the dynamics of a cold sample of Rydberg atoms with high permanent electric dipole moments. The dipolar state can be created using an adiabatic passage through an avoided crossing between an S-like state and a linear Stark state. The simulations yield the pair-correlation functions (PCF) of the atom samples, which allow us to extract the motion of Rydberg-atom pairs in the many-body system. The results reveal the strength and the anisotropic character of the underlying interaction. The simulation is employed to test the suitability of experimental methods designed to derive interaction parameters from PCF. Insight is obtained about the stability of the method against variation of experimentally relevant parameters. Transient correlations due to interaction-induced heating are observed. (paper)

  6. Matching pursuit and source deflation for sparse EEG/MEG dipole moment estimation.

    Science.gov (United States)

    Wu, Shun Chi; Swindlehurst, A Lee

    2013-08-01

    In this paper, we propose novel matching pursuit (MP)-based algorithms for EEG/MEG dipole source localization and parameter estimation for multiple measurement vectors with constant sparsity. The algorithms combine the ideas of MP for sparse signal recovery and source deflation, as employed in estimation via alternating projections. The source-deflated matching pursuit (SDMP) approach mitigates the problem of residual interference inherent in sequential MP-based methods or recursively applied (RAP)-MUSIC. Furthermore, unlike prior methods based on alternating projection, SDMP allows one to efficiently estimate the dipole orientation in addition to its location. Simulations show that the proposed algorithms outperform existing techniques under various conditions, including those with highly correlated sources. Results using real EEG data from auditory experiments are also presented to illustrate the performance of these algorithms.

  7. Interplay between Coulomb-focusing and non-dipole effects in strong-field ionization with elliptical polarization

    Science.gov (United States)

    Daněk, J.; Klaiber, M.; Hatsagortsyan, K. Z.; Keitel, C. H.; Willenberg, B.; Maurer, J.; Mayer, B. W.; Phillips, C. R.; Gallmann, L.; Keller, U.

    2018-06-01

    We study strong-field ionization and rescattering beyond the long-wavelength limit of the dipole approximation with elliptically polarized mid-IR laser pulses. Full three-dimensional photoelectron momentum distributions (PMDs) measured with velocity map imaging and tomographic reconstruction revealed an unexpected sharp ridge structure in the polarization plane (2018 Phys. Rev. A 97 013404). This thin line-shaped ridge structure for low-energy photoelectrons is correlated with the ellipticity-dependent asymmetry of the PMD along the beam propagation direction. The peak of the projection of the PMD onto the beam propagation axis is shifted from negative to positive values when the sharp ridge fades away with increasing ellipticity. With classical trajectory Monte Carlo simulations and analytical analysis, we study the underlying physics of this feature. The underlying physics is based on the interplay between the lateral drift of the ionized electron, the laser magnetic field induced drift in the laser propagation direction, and Coulomb focusing. To apply our observations to emerging techniques relying on strong-field ionization processes, including time-resolved holography and molecular imaging, we present a detailed classical trajectory-based analysis of our observations. The analysis leads to the explanation of the fine structure of the ridge and its non-dipole behavior upon rescattering while introducing restrictions on the ellipticity. These restrictions as well as the ionization and recollision phases provide additional observables to gain information on the timing of the ionization and recollision process and non-dipole properties of the ionization process.

  8. Earthquake source model using strong motion displacement

    Indian Academy of Sciences (India)

    The strong motion displacement records available during an earthquake can be treated as the response of the earth as the a structural system to unknown forces acting at unknown locations. Thus, if the part of the earth participating in ground motion is modelled as a known finite elastic medium, one can attempt to model the ...

  9. Real-Time Localization of Moving Dipole Sources for Tracking Multiple Free-Swimming Weakly Electric Fish

    Science.gov (United States)

    Jun, James Jaeyoon; Longtin, André; Maler, Leonard

    2013-01-01

    In order to survive, animals must quickly and accurately locate prey, predators, and conspecifics using the signals they generate. The signal source location can be estimated using multiple detectors and the inverse relationship between the received signal intensity (RSI) and the distance, but difficulty of the source localization increases if there is an additional dependence on the orientation of a signal source. In such cases, the signal source could be approximated as an ideal dipole for simplification. Based on a theoretical model, the RSI can be directly predicted from a known dipole location; but estimating a dipole location from RSIs has no direct analytical solution. Here, we propose an efficient solution to the dipole localization problem by using a lookup table (LUT) to store RSIs predicted by our theoretically derived dipole model at many possible dipole positions and orientations. For a given set of RSIs measured at multiple detectors, our algorithm found a dipole location having the closest matching normalized RSIs from the LUT, and further refined the location at higher resolution. Studying the natural behavior of weakly electric fish (WEF) requires efficiently computing their location and the temporal pattern of their electric signals over extended periods. Our dipole localization method was successfully applied to track single or multiple freely swimming WEF in shallow water in real-time, as each fish could be closely approximated by an ideal current dipole in two dimensions. Our optimized search algorithm found the animal’s positions, orientations, and tail-bending angles quickly and accurately under various conditions, without the need for calibrating individual-specific parameters. Our dipole localization method is directly applicable to studying the role of active sensing during spatial navigation, or social interactions between multiple WEF. Furthermore, our method could be extended to other application areas involving dipole source

  10. Real-Time Localization of Moving Dipole Sources for Tracking Multiple Free-Swimming Weakly Electric Fish.

    Directory of Open Access Journals (Sweden)

    James Jaeyoon Jun

    Full Text Available In order to survive, animals must quickly and accurately locate prey, predators, and conspecifics using the signals they generate. The signal source location can be estimated using multiple detectors and the inverse relationship between the received signal intensity (RSI and the distance, but difficulty of the source localization increases if there is an additional dependence on the orientation of a signal source. In such cases, the signal source could be approximated as an ideal dipole for simplification. Based on a theoretical model, the RSI can be directly predicted from a known dipole location; but estimating a dipole location from RSIs has no direct analytical solution. Here, we propose an efficient solution to the dipole localization problem by using a lookup table (LUT to store RSIs predicted by our theoretically derived dipole model at many possible dipole positions and orientations. For a given set of RSIs measured at multiple detectors, our algorithm found a dipole location having the closest matching normalized RSIs from the LUT, and further refined the location at higher resolution. Studying the natural behavior of weakly electric fish (WEF requires efficiently computing their location and the temporal pattern of their electric signals over extended periods. Our dipole localization method was successfully applied to track single or multiple freely swimming WEF in shallow water in real-time, as each fish could be closely approximated by an ideal current dipole in two dimensions. Our optimized search algorithm found the animal's positions, orientations, and tail-bending angles quickly and accurately under various conditions, without the need for calibrating individual-specific parameters. Our dipole localization method is directly applicable to studying the role of active sensing during spatial navigation, or social interactions between multiple WEF. Furthermore, our method could be extended to other application areas involving dipole

  11. Nonlinear estimation-based dipole source localization for artificial lateral line systems

    International Nuclear Information System (INIS)

    Abdulsadda, Ahmad T; Tan Xiaobo

    2013-01-01

    As a flow-sensing organ, the lateral line system plays an important role in various behaviors of fish. An engineering equivalent of a biological lateral line is of great interest to the navigation and control of underwater robots and vehicles. A vibrating sphere, also known as a dipole source, can emulate the rhythmic movement of fins and body appendages, and has been widely used as a stimulus in the study of biological lateral lines. Dipole source localization has also become a benchmark problem in the development of artificial lateral lines. In this paper we present two novel iterative schemes, referred to as Gauss–Newton (GN) and Newton–Raphson (NR) algorithms, for simultaneously localizing a dipole source and estimating its vibration amplitude and orientation, based on the analytical model for a dipole-generated flow field. The performance of the GN and NR methods is first confirmed with simulation results and the Cramer–Rao bound (CRB) analysis. Experiments are further conducted on an artificial lateral line prototype, consisting of six millimeter-scale ionic polymer–metal composite sensors with intra-sensor spacing optimized with CRB analysis. Consistent with simulation results, the experimental results show that both GN and NR schemes are able to simultaneously estimate the source location, vibration amplitude and orientation with comparable precision. Specifically, the maximum localization error is less than 5% of the body length (BL) when the source is within the distance of one BL. Experimental results have also shown that the proposed schemes are superior to the beamforming method, one of the most competitive approaches reported in literature, in terms of accuracy and computational efficiency. (paper)

  12. Radiation from a pulsed dipole source in a moving magnetized plasma

    International Nuclear Information System (INIS)

    Gavrilenko, V. G.; Petrov, E. Yu.; Pikulin, V. D.; Sutyagina, D. A.

    2006-01-01

    The problem of radiation from a pulsed dipole source in a moving magnetized plasma described by a diagonal permittivity tensor is considered. An exact solution describing the spatiotemporal behavior of the excited electromagnetic field is obtained. The shape of an electromagnetic pulse that is generated by the source and propagates at different angles to both the direction of the external magnetic field and the direction of plasma motion is investigated. It is found that even nonrelativistic motion of the plasma medium can substantially influence the parameters of radiation from prescribed unsteady sources

  13. Multiple Signal Classification Algorithm Based Electric Dipole Source Localization Method in an Underwater Environment

    Directory of Open Access Journals (Sweden)

    Yidong Xu

    2017-10-01

    Full Text Available A novel localization method based on multiple signal classification (MUSIC algorithm is proposed for positioning an electric dipole source in a confined underwater environment by using electric dipole-receiving antenna array. In this method, the boundary element method (BEM is introduced to analyze the boundary of the confined region by use of a matrix equation. The voltage of each dipole pair is used as spatial-temporal localization data, and it does not need to obtain the field component in each direction compared with the conventional fields based localization method, which can be easily implemented in practical engineering applications. Then, a global-multiple region-conjugate gradient (CG hybrid search method is used to reduce the computation burden and to improve the operation speed. Two localization simulation models and a physical experiment are conducted. Both the simulation results and physical experiment result provide accurate positioning performance, with the help to verify the effectiveness of the proposed localization method in underwater environments.

  14. Modeling of Dipole and Quadrupole Fringe-Field Effects for the Advanced Photon Source Upgrade Lattice

    Energy Technology Data Exchange (ETDEWEB)

    Borland, M.; Lindberg, R.

    2017-06-01

    The proposed upgrade of the Advanced Photon Source (APS) to a multibend-achromat lattice requires shorter and much stronger quadrupole magnets than are present in the existing ring. This results in longitudinal gradient profiles that differ significantly from a hard-edge model. Additionally, the lattice assumes the use of five-segment longitudinal gradient dipoles. Under these circumstances, the effects of fringe fields and detailed field distributions are of interest. We evaluated the effect of soft-edge fringe fields on the linear optics and chromaticity, finding that compensation for these effects is readily accomplished. In addition, we evaluated the reliability of standard methods of simulating hardedge nonlinear fringe effects in quadrupoles.

  15. Magnetic dipole moments of 58Cu and 59Cu by in-source laser spectroscopy

    International Nuclear Information System (INIS)

    Stone, N. J.; Koester, U.; Stone, J. Rikovska; Fedorov, D. V.; Fedoseyev, V. N.; Flanagan, K. T.; Hass, M.; Lakshmi, S.

    2008-01-01

    Online measurements of the magnetic dipole moments and isotope shifts of 58 Cu and 59 Cu by the in-source laser spectroscopy method are reported. The results for the magnetic moments are μ ( 58 Cu) =+0.52(8) μ N ,μ( 59 Cu) =+1.84(3) μ N and for the isotope shifts δν 59,65 =1.72(22) GHz and δν 58,65 =1.99(30) GHz in the transition from the 3d 10 4s 2 S 1/2 ground state to the 3d 10 4p 2 P 1/2 state in Cu I. The magnetic moment of 58 Cu is discussed in the context of the strength of the subshell closure at 56 Ni, additivity rules and large-scale shell model calculations

  16. The algorithms for calculating synthetic seismograms from a dipole source using the derivatives of Green's function

    Science.gov (United States)

    Pavlov, V. M.

    2017-07-01

    The problem of calculating complete synthetic seismograms from a point dipole with an arbitrary seismic moment tensor in a plane parallel medium composed of homogeneous elastic isotropic layers is considered. It is established that the solutions of the system of ordinary differential equations for the motion-stress vector have a reciprocity property, which allows obtaining a compact formula for the derivative of the motion vector with respect to the source depth. The reciprocity theorem for Green's functions with respect to the interchange of the source and receiver is obtained for a medium with cylindrical boundary. The differentiation of Green's functions with respect to the coordinates of the source leads to the same calculation formulas as the algorithm developed in the previous work (Pavlov, 2013). A new algorithm appears when the derivatives with respect to the horizontal coordinates of the source is replaced by the derivatives with respect to the horizontal coordinates of the receiver (with the minus sign). This algorithm is more transparent, compact, and economic than the previous one. It requires calculating the wavenumbers associated with Bessel function's roots of order 0 and order 1, whereas the previous algorithm additionally requires the second order roots.

  17. Dipole estimation errors due to not incorporating anisotropic conductivities in realistic head models for EEG source analysis

    Science.gov (United States)

    Hallez, Hans; Staelens, Steven; Lemahieu, Ignace

    2009-10-01

    EEG source analysis is a valuable tool for brain functionality research and for diagnosing neurological disorders, such as epilepsy. It requires a geometrical representation of the human head or a head model, which is often modeled as an isotropic conductor. However, it is known that some brain tissues, such as the skull or white matter, have an anisotropic conductivity. Many studies reported that the anisotropic conductivities have an influence on the calculated electrode potentials. However, few studies have assessed the influence of anisotropic conductivities on the dipole estimations. In this study, we want to determine the dipole estimation errors due to not taking into account the anisotropic conductivities of the skull and/or brain tissues. Therefore, head models are constructed with the same geometry, but with an anisotropically conducting skull and/or brain tissue compartment. These head models are used in simulation studies where the dipole location and orientation error is calculated due to neglecting anisotropic conductivities of the skull and brain tissue. Results show that not taking into account the anisotropic conductivities of the skull yields a dipole location error between 2 and 25 mm, with an average of 10 mm. When the anisotropic conductivities of the brain tissues are neglected, the dipole location error ranges between 0 and 5 mm. In this case, the average dipole location error was 2.3 mm. In all simulations, the dipole orientation error was smaller than 10°. We can conclude that the anisotropic conductivities of the skull have to be incorporated to improve the accuracy of EEG source analysis. The results of the simulation, as presented here, also suggest that incorporation of the anisotropic conductivities of brain tissues is not necessary. However, more studies are needed to confirm these suggestions.

  18. Dipole estimation errors due to not incorporating anisotropic conductivities in realistic head models for EEG source analysis

    International Nuclear Information System (INIS)

    Hallez, Hans; Staelens, Steven; Lemahieu, Ignace

    2009-01-01

    EEG source analysis is a valuable tool for brain functionality research and for diagnosing neurological disorders, such as epilepsy. It requires a geometrical representation of the human head or a head model, which is often modeled as an isotropic conductor. However, it is known that some brain tissues, such as the skull or white matter, have an anisotropic conductivity. Many studies reported that the anisotropic conductivities have an influence on the calculated electrode potentials. However, few studies have assessed the influence of anisotropic conductivities on the dipole estimations. In this study, we want to determine the dipole estimation errors due to not taking into account the anisotropic conductivities of the skull and/or brain tissues. Therefore, head models are constructed with the same geometry, but with an anisotropically conducting skull and/or brain tissue compartment. These head models are used in simulation studies where the dipole location and orientation error is calculated due to neglecting anisotropic conductivities of the skull and brain tissue. Results show that not taking into account the anisotropic conductivities of the skull yields a dipole location error between 2 and 25 mm, with an average of 10 mm. When the anisotropic conductivities of the brain tissues are neglected, the dipole location error ranges between 0 and 5 mm. In this case, the average dipole location error was 2.3 mm. In all simulations, the dipole orientation error was smaller than 10 deg. We can conclude that the anisotropic conductivities of the skull have to be incorporated to improve the accuracy of EEG source analysis. The results of the simulation, as presented here, also suggest that incorporation of the anisotropic conductivities of brain tissues is not necessary. However, more studies are needed to confirm these suggestions.

  19. Contribution of the source velocity to the scattering of electromagnetic fields caused by airborne magnetic dipoles

    International Nuclear Information System (INIS)

    Sampaio, Edson Emanoel Starteri

    2014-01-01

    The velocity of controlled airborne sources of electromagnetic geophysical surveys plays an additional role in the scattering of the fields by the earth. Therefore, it is necessary to investigate its contribution in the space and time variation of secondary electromagnetic fields. The model of a vertical magnetic dipole moving at a constant speed along a horizontal line in the air and above a homogeneous conductive half-space constitutes a first approach to stress the kinematic aspect and determine the difference between the fields due to an airborne and a static source. The magnetic moment of the source is equal to 10 4  A m 2 , its height is 120 m, and the horizontal and vertical separations between it and the receiver are, respectively, equal to 100 and 50 m: these values of the model are typical of towed-bird airborne TDEM surveys. We employed four values for the common velocities of source and receiver (0, 60, 80, and 100 m s −1 ), four values of the conductivity of the half-space (0.5, 0.1, 0.05, and 0.01 S m −1 ), and two causal source currents (box with periods of 80 and 10 ms and periodic with frequency values of 12.5 and 100 Hz). The results demonstrate that the relative velocity between source and medium yields a measurable variation compared to the static condition. Therefore, it must be taken into consideration by compensating the discrepancy in measured data employing the respective theoretical result. The results also show that it is necessary to adjust the concepts of time and frequency domain for electromagnetic measurements with traveling sources. (paper)

  20. Solid core dipoles and switching power supplies: lower cost light sources?

    Science.gov (United States)

    Benesch, J.; Philip, S.

    2015-05-01

    As a result of improvements in power semiconductors, moderate frequency switching supplies can now provide the hundreds of amps typically required by accelerators with zero-to-peak noise in the kHz region ~ 0.06% in current or voltage mode. Modeling was undertaken using a finite electromagnetic program to determine if eddy currents induced in the solid steel of CEBAF magnets and small supplemental additions would bring the error fields down to the 5ppm level needed for beam quality. The expected maximum field of the magnet under consideration is 0.85 T and the DC current required to produce that field is used in the calculations. An additional 0.1% current ripple is added to the DC current at discrete frequencies 360 Hz, 720 Hz or 7200 Hz. Over the region of the pole within 0.5% of the central integrated BdL the resulting AC field changes can be reduced to less than 1% of the 0.1% input ripple for all frequencies, and a sixth of that at 7200 Hz. Doubling the current, providing 1.5 T central field, yielded the same fractional reduction in ripple at the beam for the cases checked. A small dipole was measured at 60, 120, 360 and 720 Hz in two conditions and the results compared to the larger model for the latter two frequencies with surprisingly good agreement. For light sources with aluminum vacuum vessels and full energy linac injection, the combination of solid core dipoles and switching power supplies may result in significant cost savings. The work may also be used to guide retrofit of existing machines to reduce the level of ripple in the particle beam path.

  1. Generating picosecond x-ray pulses in synchrotron light sources using dipole kickers

    Directory of Open Access Journals (Sweden)

    W. Guo

    2007-02-01

    Full Text Available The duration of the x-ray pulse generated at a synchrotron light source is typically tens of picoseconds. Shorter pulses are highly desired by the users. In electron storage rings, the vertical beam size is usually orders of magnitude less than the bunch length due to radiation damping; therefore, a shorter pulse can be obtained by slitting the vertically tilted bunch. Zholents proposed tilting the bunch using rf deflection. We found that tilted bunches can also be generated by a dipole magnet kick. A vertical tilt is developed after the kick in the presence of nonzero chromaticity. The tilt was successfully observed and a 4.2-ps pulse was obtained from a 27-ps electron bunch at the Advanced Photon Source. Based on this principle, we propose a short-pulse generation scheme that produces picosecond x-ray pulses at a repetition rate of 1–2 kHz, which can be used for pump-probe experiments.

  2. Extreme enhancement of blocking temperature by strong magnetic dipoles interaction of α-Fe nanoparticle-based high-density agglomerate

    International Nuclear Information System (INIS)

    Kura, H; Takahashi, M; Ogawa, T

    2011-01-01

    High-volume fraction α-Fe nanoparticle (NP) agglomerates were prepared using chemically synthesized NPs. In the agglomerate, NPs are separated by surfactant and NP superlattice with a hexagonal close-packed structure is locally realized. Volume fractions of NPs at 20% and 42% were obtained in agglomerates consisting of 2.9 nm and 8.2 nm diameter NPs, respectively. The high saturation magnetization of α-Fe NPs and high volume fraction of NPs in the agglomerate provide strong magnetic dipole-dipole interaction. The interaction energy of the agglomerate became much larger than the anisotropic energy of individual NPs. As a result, the blocking temperature of the 8.2 nm NP agglomerate was significantly enhanced from 52.2 K to around 500 K. (fast track communication)

  3. Explosion source strong ground motions in the Mississippi embayment

    Science.gov (United States)

    Langston, C.A.; Bodin, P.; Powell, C.; Withers, M.; Horton, S.; Mooney, W.

    2006-01-01

    Two strong-motion arrays were deployed for the October 2002 Embayment Seismic Excitation Experiment to study the spatial variation of strong ground motions in the deep, unconsolidated sediments of the Mississippi embayment because there are no comparable strong-motion data from natural earthquakes in the area. Each linear array consisted of eight three-component K2 accelerographs spaced 15 m apart situated 1.2 and 2.5 kin from 2268-kg and 1134-kg borehole explosion sources, respectively. The array data show distinct body-wave and surface-wave arrivals that propagate within the thick, unconsolidated sedimentary column, the high-velocity basement rocks, and small-scale structure near the surface. Time-domain coherence of body-wave and surface-wave arrivals is computed for acceleration, velocity, and displacement time windows. Coherence is high for relatively low-frequency verticalcomponent Rayleigh waves and high-frequency P waves propagating across the array. Prominent high-frequency PS conversions seen on radial components, a proxy for the direct S wave from earthquake sources, lose coherence quickly over the 105-m length of the array. Transverse component signals are least coherent for any ground motion and appear to be highly scattered. Horizontal phase velocity is computed by using the ratio of particle velocity to estimates of the strain based on a plane-wave-propagation model. The resulting time-dependent phase-velocity map is a useful way to infer the propagation mechanisms of individual seismic phases and time windows of three-component waveforms. Displacement gradient analysis is a complementary technique for processing general spatial-array data to obtain horizontal slowness information.

  4. Experimental Verification of Isotropic Radiation from a Coherent Dipole Source via Electric-Field-Driven LC Resonator Metamaterials

    Science.gov (United States)

    Tichit, Paul-Henri; Burokur, Shah Nawaz; Qiu, Cheng-Wei; de Lustrac, André

    2013-09-01

    It has long been conjectured that isotropic radiation by a simple coherent source is impossible due to changes in polarization. Though hypothetical, the isotropic source is usually taken as the reference for determining a radiator’s gain and directivity. Here, we demonstrate both theoretically and experimentally that an isotropic radiator can be made of a simple and finite source surrounded by electric-field-driven LC resonator metamaterials designed by space manipulation. As a proof-of-concept demonstration, we show the first isotropic source with omnidirectional radiation from a dipole source (applicable to all distributed sources), which can open up several possibilities in axion electrodynamics, optical illusion, novel transformation-optic devices, wireless communication, and antenna engineering. Owing to the electric- field-driven LC resonator realization scheme, this principle can be readily applied to higher frequency regimes where magnetism is usually not present.

  5. Combining virtual observatory and equivalent source dipole approaches to describe the geomagnetic field with Swarm measurements

    Science.gov (United States)

    Saturnino, Diana; Langlais, Benoit; Amit, Hagay; Civet, François; Mandea, Mioara; Beucler, Éric

    2018-03-01

    A detailed description of the main geomagnetic field and of its temporal variations (i.e., the secular variation or SV) is crucial to understanding the geodynamo. Although the SV is known with high accuracy at ground magnetic observatory locations, the globally uneven distribution of the observatories hampers the determination of a detailed global pattern of the SV. Over the past two decades, satellites have provided global surveys of the geomagnetic field which have been used to derive global spherical harmonic (SH) models through some strict data selection schemes to minimise external field contributions. However, discrepancies remain between ground measurements and field predictions by these models; indeed the global models do not reproduce small spatial scales of the field temporal variations. To overcome this problem we propose to directly extract time series of the field and its temporal variation from satellite measurements as it is done at observatory locations. We follow a Virtual Observatory (VO) approach and define a global mesh of VOs at satellite altitude. For each VO and each given time interval we apply an Equivalent Source Dipole (ESD) technique to reduce all measurements to a unique location. Synthetic data are first used to validate the new VO-ESD approach. Then, we apply our scheme to data from the first two years of the Swarm mission. For the first time, a 2.5° resolution global mesh of VO time series is built. The VO-ESD derived time series are locally compared to ground observations as well as to satellite-based model predictions. Our approach is able to describe detailed temporal variations of the field at local scales. The VO-ESD time series are then used to derive global spherical harmonic models. For a simple SH parametrization the model describes well the secular trend of the magnetic field both at satellite altitude and at the surface. As more data will be made available, longer VO-ESD time series can be derived and consequently used to

  6. Design, fabrication, and calibration of curved integral coils for measuring transfer function, uniformity, and effective length of LBL ALS [Lawrence Berkeley Laboratory Advanced Light Source] Booster Dipole Magnets

    International Nuclear Information System (INIS)

    Green, M.I.; Nelson, D.; Marks, S.; Gee, B.; Wong, W.; Meneghetti, J.

    1989-03-01

    A matched pair of curved integral coils has been designed, fabricated and calibrated at Lawrence Berkeley Laboratory for measuring Advanced Light Source (ALS) Booster Dipole Magnets. Distinctive fabrication and calibration techniques are described. The use of multifilar magnet wire in fabrication integral search coils is described. Procedures used and results of AC and DC measurements of transfer function, effective length and uniformity of the prototype booster dipole magnet are presented in companion papers. 8 refs

  7. Brain electric correlates of strong belief in paranormal phenomena: intracerebral EEG source and regional Omega complexity analyses.

    Science.gov (United States)

    Pizzagalli, D; Lehmann, D; Gianotti, L; Koenig, T; Tanaka, H; Wackermann, J; Brugger, P

    2000-12-22

    The neurocognitive processes underlying the formation and maintenance of paranormal beliefs are important for understanding schizotypal ideation. Behavioral studies indicated that both schizotypal and paranormal ideation are based on an overreliance on the right hemisphere, whose coarse rather than focussed semantic processing may favor the emergence of 'loose' and 'uncommon' associations. To elucidate the electrophysiological basis of these behavioral observations, 35-channel resting EEG was recorded in pre-screened female strong believers and disbelievers during resting baseline. EEG data were subjected to FFT-Dipole-Approximation analysis, a reference-free frequency-domain dipole source modeling, and Regional (hemispheric) Omega Complexity analysis, a linear approach estimating the complexity of the trajectories of momentary EEG map series in state space. Compared to disbelievers, believers showed: more right-located sources of the beta2 band (18.5-21 Hz, excitatory activity); reduced interhemispheric differences in Omega complexity values; higher scores on the Magical Ideation scale; more general negative affect; and more hypnagogic-like reveries after a 4-min eyes-closed resting period. Thus, subjects differing in their declared paranormal belief displayed different active, cerebral neural populations during resting, task-free conditions. As hypothesized, believers showed relatively higher right hemispheric activation and reduced hemispheric asymmetry of functional complexity. These markers may constitute the neurophysiological basis for paranormal and schizotypal ideation.

  8. 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

  9. Underwater tracking of a moving dipole source using an artificial lateral line: algorithm and experimental validation with ionic polymer–metal composite flow sensors

    International Nuclear Information System (INIS)

    Abdulsadda, Ahmad T; Tan, Xiaobo

    2013-01-01

    Motivated by the lateral line system of fish, arrays of flow sensors have been proposed as a new sensing modality for underwater robots. Existing studies on such artificial lateral lines (ALLs) have been mostly focused on the localization of a fixed underwater vibrating sphere (dipole source). In this paper we examine the problem of tracking a moving dipole source using an ALL system. Based on an analytical model for the moving dipole-generated flow field, we formulate a nonlinear estimation problem that aims to minimize the error between the measured and model-predicted magnitudes of flow velocities at the sensor sites, which is subsequently solved with the Gauss–Newton scheme. A sliding discrete Fourier transform (SDFT) algorithm is proposed to efficiently compute the evolving signal magnitudes based on the flow velocity measurements. Simulation indicates that it is adequate and more computationally efficient to use only the signal magnitudes corresponding to the dipole vibration frequency. Finally, experiments conducted with an artificial lateral line consisting of six ionic polymer–metal composite (IPMC) flow sensors demonstrate that the proposed scheme is able to simultaneously locate the moving dipole and estimate its vibration amplitude and traveling speed with small errors. (paper)

  10. Oscillating dipole with fractional quantum source in Aharonov-Bohm electrodynamics

    Directory of Open Access Journals (Sweden)

    Giovanni Modanese

    Full Text Available We show, in the case of a special dipolar source, that electromagnetic fields in fractional quantum mechanics have an unexpected space dependence: propagating fields may have non-transverse components, and the distinction between near-field zone and wave zone is blurred. We employ an extension of Maxwell theory, Aharonov-Bohm electrodynamics, which is compatible with currents jν conserved globally but not locally; we have derived in another work the field equation ∂μFμν=jν+iν, where iν is a non-local function of jν, called “secondary current”. Y. Wei has recently proved that the probability current in fractional quantum mechanics is in general not locally conserved. We compute this current for a Gaussian wave packet with fractional parameter a=3/2 and find that in a suitable limit it can be approximated by our simplified dipolar source. Currents which are not locally conserved may be present also in other quantum systems whose wave functions satisfy non-local equations. The combined electromagnetic effects of such sources and their secondary currents are very interesting both theoretically and for potential applications. Keywords: Generalized Maxwell theory, Fractional Schrödinger equation, Local current conservation

  11. Enhanced Light Output of Dipole Source in GaN-Based Nanorod Light-Emitting Diodes by Silver Localized Surface Plasmon

    Directory of Open Access Journals (Sweden)

    Huamao Huang

    2014-01-01

    Full Text Available The light output of dipole source in three types of light-emitting diodes (LEDs, including the conventional planar LED, the nanorod LED, and the localized surface plasmon (LSP assisted LED by inserting silver nanoparticles in the gaps between nanorods, was studied by use of two-dimensional finite difference time domain method. The height of nanorod and the size of silver nanoparticles were variables for discussion. Simulation results show that a large height of nanorod induces strong wavelength selectivity, which can be significantly enhanced by LSP. On condition that the height of nanorod is 400 nm, the diameter of silver nanoparticle is 100 nm, and the wavelength is 402.7 nm, the light-output efficiency for LSP assisted LED is enhanced by 190% or 541% as compared to the nanorod counterpart or the planar counterpart, respectively. The space distribution of Poynting vector was present to demonstrate the significant enhancement of light output at the resonant wavelength of LSP.

  12. Extremely Low Frequency (ELF) Propagation Formulas for Dipole Sources Radiating in a Spherical Earth-Ionosphere Waveguide

    National Research Council Canada - National Science Library

    Casey, Joseph

    2002-01-01

    .... In these formulas, the earth and ionosphere boundaries are modeled as scalar surface impedances. The spherical waveguide formulas are applied to predict the electromagnetic fields produced by vertical and horizontal electric dipoles...

  13. A novel energy transfer inducing strong enhancement of electric dipole transition in Na3Mo12PO40:xEu3+ phosphors

    Science.gov (United States)

    Long, Jinqiao; Wang, Tianman; Luo, Zhirong; Gao, Yong; Song, Baoling; Liang, Jing; Liao, Sen; Huang, Yingheng; Zhang, Huaxin

    2017-08-01

    A series of Na3Mo12PO40:xEu3+ phosphors have been successfully synthesized by a solid-state method, and characterized by powder x-ray diffraction (PXRD). The PXRD results confirm that the samples have crystal phases of Na3Mo12PO40. For PL spectra of Na3Mo12PO40:2.0Eu3+ excited by 394 and 465 nm, R (R is the peak area ratio of 5D0  →  7F2 to 5D0  →  7F1) is only 1.46 with an excitation of 394 nm, but increases to 3.03 with an excitation of 465 nm. Furthermore, a new enhancement of electric dipole transition is observed. Emission spectrum (PL) intensity at 617 nm excited by 465 nm is 1.95 times as high as the excitation spectrum (PLE) intensity at 465 nm. Thus, cooperative energy transfers from the magnetic dipole (MD) Eu3+ center to the electric dipole (ED) Eu3+ center when excited by 465 nm is demonstrated for the new fluorescent behavior.

  14. NSLS dipole power source

    International Nuclear Information System (INIS)

    Bagley, G.P.

    1980-01-01

    An SRC DC to DC converter is described which will operate at an output of 275 kW and will supply current to electron storage ring magnets requiring 5 hr stability of 50 ppM. The operation of this modified chopper is described and design equations are presented, along with the system control loop description

  15. NSLS dipole power source

    International Nuclear Information System (INIS)

    Bagley, G.P.

    1980-01-01

    An SCR DC to DC converter is described which will operate at an output of 275 kW and will supply current to electron storage ring magnets requiring 5 h stability of 50 ppM. The operation of this modified chopper is described and design equations are presented, along with the system control loop description

  16. Field distributions and particle optics in main bending dipoles of Oak Ridge Spallation Neutron Source accumulator ring

    International Nuclear Information System (INIS)

    Wang, J.G.

    2013-01-01

    The SNS accumulator ring employs 32 electro-magnetic dipoles to bend proton beams. The dipoles are typical sector magnets with relatively large aperture and short length. Thus, how to correctly treat magnetic fringe fields in the devices remains as a question. We have performed 3D computer simulations to study magnetic field distributions in the dipoles. Further, we have analyzed particle optics based on the space-dependent curvature and focusing functions in the magnets. The effect of magnetic fringe fields on the particle motion, especially the focusing/defocusing and dispersion, is investigated. The lens parameters, including the second-order aberrations, are derived and compared with the design hard-edge parameters used in the ring lattice calculations

  17. The DC field components of horizontal and vertical electric dipole sources immersed in three-layered stratified media

    Directory of Open Access Journals (Sweden)

    D. Llanwyn Jones

    Full Text Available Formulas for computing the Cartesian components of the static (DC fields of horizontal electric dipoles ( HEDs and vertical electric dipoles ( VEDs located in the central zone of a three-layer horizontally stratified medium are derived and presented in a summary form suitable for immediate computation. Formulas are given for the electric and magnetic field components in the upper and central regions. In the general case the computation involves the summation of a convergent infinite series. For the particular case of an infinitely thick central region (corresponding to the two-layer problem, the analysis produces relatively simple closed-form equations for the field components which are suitable for a 'hand calculation'. Specimen calculations for dipoles in seawaters are included and the derived results are compared with computations made using an ac model.

  18. The DC field components of horizontal and vertical electric dipole sources immersed in three-layered stratified media

    Directory of Open Access Journals (Sweden)

    D. Llanwyn Jones

    1997-04-01

    Full Text Available Formulas for computing the Cartesian components of the static (DC fields of horizontal electric dipoles ( HEDs and vertical electric dipoles ( VEDs located in the central zone of a three-layer horizontally stratified medium are derived and presented in a summary form suitable for immediate computation. Formulas are given for the electric and magnetic field components in the upper and central regions. In the general case the computation involves the summation of a convergent infinite series. For the particular case of an infinitely thick central region (corresponding to the two-layer problem, the analysis produces relatively simple closed-form equations for the field components which are suitable for a 'hand calculation'. Specimen calculations for dipoles in seawaters are included and the derived results are compared with computations made using an ac model.

  19. Measuring device for strong gamma-ray sources; Dispositif de mesure des fortes sources emettrices {gamma}

    Energy Technology Data Exchange (ETDEWEB)

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

    1956-07-01

    We are given the description of a hollow argon-filled cylindrical ionisation chamber which is to be used to measure gamma-emitting sources. The instrument is currently used at the Measures Department in routine gauging of some radioelements. Sources are introduced into the central part of the chamber through a remote handling device. Measures are directly registered, it is not worth while removing the source from the container; a deviation of the source has little effect on the ionization current. The chamber was gauged to test such elements as: {sup 198}Au, {sup 60}Co, {sup 192}Ir, {sup 24}Na, {sup 137}Cs. Its measuring power approximately ranges from 100 micro-curies to 5 curies. (author) [French] On decrit une chambre d'ionisation cylindrique creuse, a remplissage d'argon, destinee a la mesure des sources emettrices {gamma}. Cet appareil est utilise couramment par la Section Mesures pour l'etalonnage de routine d'un certain nombre de radioelements. Les sources sont mises en place au centre de la chambre par un dispositif de manipulation a distance. La mesure est faite directement, sans qu'il soit necessaire d'extraire la source de son container; un decentrement de la source n'a en effet pas d'influence sensible sur le courant d'ionisation. Cette chambre d'ionisation a ete etalonnee pour divers radioelements: {sup 198}Au, {sup 60}Co, {sup 192}Ir, {sup 24}Na, {sup 137}Cs. La flamme d'activite mesurable s'etend de 100 microcuries a 5 curies, environ. (auteur)

  20. Strong Schottky barrier reduction at Au-catalyst/GaAs-nanowire interfaces by electric dipole formation and Fermi-level unpinning.

    Science.gov (United States)

    Suyatin, Dmitry B; Jain, Vishal; Nebol'sin, Valery A; Trägårdh, Johanna; Messing, Maria E; Wagner, Jakob B; Persson, Olof; Timm, Rainer; Mikkelsen, Anders; Maximov, Ivan; Samuelson, Lars; Pettersson, Håkan

    2014-01-01

    Nanoscale contacts between metals and semiconductors are critical for further downscaling of electronic and optoelectronic devices. However, realizing nanocontacts poses significant challenges since conventional approaches to achieve ohmic contacts through Schottky barrier suppression are often inadequate. Here we report the realization and characterization of low n-type Schottky barriers (~0.35 eV) formed at epitaxial contacts between Au-In alloy catalytic particles and GaAs-nanowires. In comparison to previous studies, our detailed characterization, employing selective electrical contacts defined by high-precision electron beam lithography, reveals the barrier to occur directly and solely at the abrupt interface between the catalyst and nanowire. We attribute this lowest-to-date-reported Schottky barrier to a reduced density of pinning states (~10(17) m(-2)) and the formation of an electric dipole layer at the epitaxial contacts. The insight into the physical mechanisms behind the observed low-energy Schottky barrier may guide future efforts to engineer abrupt nanoscale electrical contacts with tailored electrical properties.

  1. STRONG SOLAR WIND DYNAMIC PRESSURE PULSES: INTERPLANETARY SOURCES AND THEIR IMPACTS ON GEOSYNCHRONOUS MAGNETIC FIELDS

    International Nuclear Information System (INIS)

    Zuo, Pingbing; Feng, Xueshang; Wang, Yi; Xie, Yanqiong; Xu, Xiaojun

    2015-01-01

    In this investigation, we first present a statistical result of the interplanetary sources of very strong solar wind dynamic pressure pulses (DPPs) detected by WIND during solar cycle 23. It is found that the vast majority of strong DPPs reside within solar wind disturbances. Although the variabilities of geosynchronous magnetic fields (GMFs) due to the impact of positive DPPs have been well established, there appears to be no systematic investigations on the response of GMFs to negative DPPs. Here, we study both the decompression effects of very strong negative DPPs and the compression from strong positive DPPs on GMFs at different magnetic local time sectors. In response to the decompression of strong negative DPPs, GMFs on the dayside near dawn and near dusk on the nightside, are generally depressed. But near the midnight region, the responses of GMF are very diverse, being either positive or negative. For part of the events when GOES is located at the midnight sector, the GMF is found to abnormally increase as the result of magnetospheric decompression caused by negative DPPs. It is known that under certain conditions magnetic depression of nightside GMFs can be caused by the impact of positive DPPs. Here, we find that a stronger pressure enhancement may have a higher probability of producing the exceptional depression of GMF at the midnight region. Statistically, both the decompression effect of strong negative DPPs and the compression effect of strong positive DPPs depend on the magnetic local time, which are stronger at the noon sector

  2. STRONG SOLAR WIND DYNAMIC PRESSURE PULSES: INTERPLANETARY SOURCES AND THEIR IMPACTS ON GEOSYNCHRONOUS MAGNETIC FIELDS

    Energy Technology Data Exchange (ETDEWEB)

    Zuo, Pingbing; Feng, Xueshang; Wang, Yi [SIGMA Weather Group, State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing (China); Xie, Yanqiong [College of Meteorology and Oceanography, PLA University of Science and Technology, Nanjing (China); Xu, Xiaojun, E-mail: pbzuo@spaceweather.ac.cn, E-mail: fengx@spaceweather.ac.cn [Space Science Institute, Macau University of Science and Technology, Macao (China)

    2015-10-20

    In this investigation, we first present a statistical result of the interplanetary sources of very strong solar wind dynamic pressure pulses (DPPs) detected by WIND during solar cycle 23. It is found that the vast majority of strong DPPs reside within solar wind disturbances. Although the variabilities of geosynchronous magnetic fields (GMFs) due to the impact of positive DPPs have been well established, there appears to be no systematic investigations on the response of GMFs to negative DPPs. Here, we study both the decompression effects of very strong negative DPPs and the compression from strong positive DPPs on GMFs at different magnetic local time sectors. In response to the decompression of strong negative DPPs, GMFs on the dayside near dawn and near dusk on the nightside, are generally depressed. But near the midnight region, the responses of GMF are very diverse, being either positive or negative. For part of the events when GOES is located at the midnight sector, the GMF is found to abnormally increase as the result of magnetospheric decompression caused by negative DPPs. It is known that under certain conditions magnetic depression of nightside GMFs can be caused by the impact of positive DPPs. Here, we find that a stronger pressure enhancement may have a higher probability of producing the exceptional depression of GMF at the midnight region. Statistically, both the decompression effect of strong negative DPPs and the compression effect of strong positive DPPs depend on the magnetic local time, which are stronger at the noon sector.

  3. Improved separability of dipole sources by tripolar versus conventional disk electrodes: a modeling study using independent component analysis.

    Science.gov (United States)

    Cao, H; Besio, W; Jones, S; Medvedev, A

    2009-01-01

    Tripolar electrodes have been shown to have less mutual information and higher spatial resolution than disc electrodes. In this work, a four-layer anisotropic concentric spherical head computer model was programmed, then four configurations of time-varying dipole signals were used to generate the scalp surface signals that would be obtained with tripolar and disc electrodes, and four important EEG artifacts were tested: eye blinking, cheek movements, jaw movements, and talking. Finally, a fast fixed-point algorithm was used for signal independent component analysis (ICA). The results show that signals from tripolar electrodes generated better ICA separation results than from disc electrodes for EEG signals with these four types of artifacts.

  4. Sex-differences of face coding: evidence from larger right hemispheric M170 in men and dipole source modelling.

    Directory of Open Access Journals (Sweden)

    Hannes O Tiedt

    Full Text Available The processing of faces relies on a specialized neural system comprising bilateral cortical structures with a dominance of the right hemisphere. However, due to inconsistencies of earlier findings as well as more recent results such functional lateralization has become a topic of discussion. In particular, studies employing behavioural tasks and electrophysiological methods indicate a dominance of the right hemisphere during face perception only in men whereas women exhibit symmetric and bilateral face processing. The aim of this study was to further investigate such sex differences in hemispheric processing of personally familiar and opposite-sex faces using whole-head magnetoencephalography (MEG. We found a right-lateralized M170-component in occipito-temporal sensor clusters in men as opposed to a bilateral response in women. Furthermore, the same pattern was obtained in performing dipole localization and determining dipole strength in the M170-timewindow. These results suggest asymmetric involvement of face-responsive neural structures in men and allow to ascribe this asymmetry to the fusiform gyrus. This specifies findings from previous investigations employing event-related potentials (ERP and LORETA reconstruction methods yielding rather extended bilateral activations showing left asymmetry in women and right lateralization in men. We discuss our finding of an asymmetric fusiform activation pattern in men in terms of holistic face processing during face evaluation and sex differences with regard to visual strategies in general and interest for opposite faces in special. Taken together the pattern of hemispheric specialization observed here yields new insights into sex differences in face perception and entails further questions about interactions between biological sex, psychological gender and influences that might be stimulus-driven or task dependent.

  5. An unusually strong Einstein ring in the radio source PKS1830-211

    International Nuclear Information System (INIS)

    Jauncey, D.L.

    1991-01-01

    RADIO observations of the strong, flat-spectrum radio source PKS1830-211 revealed a double structure, with a separation of 1 arcsec, suggesting that it might be a gravitationally lensed object. We have now obtained high-resolution radio images of PKS1830-211 from several interferometric radiotelescope networks, which show an unusual elliptical ring-like structure connecting the two brighter components. The presence of the ring, and the similarity of the two brighter spots, argue strongly that this is indeed a gravitationally lensed system, specifically an Einstein ring in which lens and lensed object are closely aligned. Although the source is close to the galactic plane, it seems that both the lens and background (lensed) object are extragalactic. This object is one hundred times brighter than either of the two previously discovered radio Einstein rings, and is among the six brightest flat-spectrum sources in the sky. Its brightness makes it a peculiar object: it must involve either a chance alignment of a lensing object with an unusually bright background source, or an alignment with a less bright object but amplified to an unusual degree. (author)

  6. Strong source heat transfer simulations based on a GalerKin/Gradient - least - squares method

    International Nuclear Information System (INIS)

    Franca, L.P.; Carmo, E.G.D. do.

    1989-05-01

    Heat conduction problems with temperature-dependent strong sources are modeled by an equation with a laplacian term, a linear term and a given source distribution term. When the linear-temperature-dependent source term is much larger than the laplacian term, we have a singular perturbation problem. In this case, boundary layers are formed to satisfy the Dirichlet boundary conditions. Although this is an elliptic equation, the standard Galerkin method solution is contaminated by spurious oscillations in the neighborhood of the boundary layers. Herein we employ a Galerkin/Gradient-least-squares method which eliminates all pathological phenomena of the Galerkin method. The method is constructed by adding to the Galerkin method a mesh-dependent term obtained by the least-squares form of the gradient of the Euler-Lagrange equation. Error estimates, numerical simulations in one-and multi-dimensions are given that attest the good stability and accuracy properties of the method [pt

  7. AutoLens: Automated Modeling of a Strong Lens's Light, Mass and Source

    Science.gov (United States)

    Nightingale, J. W.; Dye, S.; Massey, Richard J.

    2018-05-01

    This work presents AutoLens, the first entirely automated modeling suite for the analysis of galaxy-scale strong gravitational lenses. AutoLens simultaneously models the lens galaxy's light and mass whilst reconstructing the extended source galaxy on an adaptive pixel-grid. The method's approach to source-plane discretization is amorphous, adapting its clustering and regularization to the intrinsic properties of the lensed source. The lens's light is fitted using a superposition of Sersic functions, allowing AutoLens to cleanly deblend its light from the source. Single component mass models representing the lens's total mass density profile are demonstrated, which in conjunction with light modeling can detect central images using a centrally cored profile. Decomposed mass modeling is also shown, which can fully decouple a lens's light and dark matter and determine whether the two component are geometrically aligned. The complexity of the light and mass models are automatically chosen via Bayesian model comparison. These steps form AutoLens's automated analysis pipeline, such that all results in this work are generated without any user-intervention. This is rigorously tested on a large suite of simulated images, assessing its performance on a broad range of lens profiles, source morphologies and lensing geometries. The method's performance is excellent, with accurate light, mass and source profiles inferred for data sets representative of both existing Hubble imaging and future Euclid wide-field observations.

  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 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

  9. 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

  10. Performance of the upgraded ultracold neutron source at Los Alamos National Laboratory and its implication for a possible neutron electric dipole moment experiment

    Science.gov (United States)

    Ito, T. M.; Adamek, E. R.; Callahan, N. B.; Choi, J. H.; Clayton, S. M.; Cude-Woods, C.; Currie, S.; Ding, X.; Fellers, D. E.; Geltenbort, P.; Lamoreaux, S. K.; Liu, C.-Y.; MacDonald, S.; Makela, M.; Morris, C. L.; Pattie, R. W.; Ramsey, J. C.; Salvat, D. J.; Saunders, A.; Sharapov, E. I.; Sjue, S.; Sprow, A. P.; Tang, Z.; Weaver, H. L.; Wei, W.; Young, A. R.

    2018-01-01

    The ultracold neutron (UCN) source at Los Alamos National Laboratory (LANL), which uses solid deuterium as the UCN converter and is driven by accelerator spallation neutrons, has been successfully operated for over 10 years, providing UCN to various experiments, as the first production UCN source based on the superthermal process. It has recently undergone a major upgrade. This paper describes the design and performance of the upgraded LANL UCN source. Measurements of the cold neutron spectrum and UCN density are presented and compared to Monte Carlo predictions. The source is shown to perform as modeled. The UCN density measured at the exit of the biological shield was 184 (32 ) UCN /cm3 , a fourfold increase from the highest previously reported. The polarized UCN density stored in an external chamber was measured to be 39 (7 ) UCN /cm3 , which is sufficient to perform an experiment to search for the nonzero neutron electric dipole moment with a one-standard-deviation sensitivity of σ (dn) =3 ×10-27e cm .

  11. Cortical processing of tactile stimuli applied in quick succession across the fingertips: temporal evolution of dipole sources revealed by magnetoencephalography.

    Science.gov (United States)

    Karageorgiou, Elissaios; Koutlas, Ioannis G; Alonso, Aurelio A; Leuthold, Arthur C; Lewis, Scott M; Georgopoulos, Apostolos P

    2008-08-01

    We used magnetoencephalography (MEG) in 10 healthy human subjects to study cortical responses to tactile stimuli applied to the fingertips of digits 2-5 of the right hand. Each stimulus lasted 50 ms and was produced by air-driven elastic membranes. Four-hundred stimuli were delivered on each finger in three temporal patterns (conditions). In the "Discrete" condition, stimuli were applied to each finger repetitively with an interstimulus interval (ISI) of 1-2 s. In the "Continuous" condition, stimuli were applied to the fingers sequentially as four-stimulus trains with zero ISI and 1-2 s intervening between trains. Finally, in the "Gap" condition, stimuli were applied as in the Continuous condition but with an ISI of 50 ms. A sensation of tactile motion across fingers (digit 2 --> digit 5) was reported by all subjects in the Continuous and Gap conditions. Cortical responses were extracted as single equivalent current dipoles over a period of 1 s following stimulus onset. In all three conditions, initial responses in left primary somatosensory cortex (SI) were observed ~20 to 50 ms after stimulus onset and were followed by additional left SI responses and bilateral responses in the secondary somatosensory cortex (SII). In addition, in the Continuous and Gap conditions, there was an activation of the precentral gyrus, the temporal aspects of which depended on the temporal relation of the administered stimuli, as follows. An ISI of 0 ms led to activation of the precentral gyrus shortly after the second stimulation, whereas an ISI of 50 ms led to activation of the precentral gyrus after the third stimulation. The current findings support results from previous studies on temporal activity patterns in SI and SII, verify the participation of the precentral gyrus during tactile motion perception and, in addition, reveal aspects of integration of sequential sensory stimulations over nonadjacent areas as well as temporal activity patterns in the postcentral and precentral

  12. 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.

  13. Strong lensing of a regular black hole with an electrodynamics source

    Science.gov (United States)

    Manna, Tuhina; Rahaman, Farook; Molla, Sabiruddin; Bhadra, Jhumpa; Shah, Hasrat Hussain

    2018-05-01

    In this paper we have investigated the gravitational lensing phenomenon in the strong field regime for a regular, charged, static black holes with non-linear electrodynamics source. We have obtained the angle of deflection and compared it to a Schwarzschild black hole and Reissner Nordström black hole with similar properties. We have also done a graphical study of the relativistic image positions and magnifications. We hope that this method may be useful in the detection of non-luminous bodies like this current black hole.

  14. Blow-Up Analysis for a Quasilinear Degenerate Parabolic Equation with Strongly Nonlinear Source

    Directory of Open Access Journals (Sweden)

    Pan Zheng

    2012-01-01

    Full Text Available We investigate the blow-up properties of the positive solution of the Cauchy problem for a quasilinear degenerate parabolic equation with strongly nonlinear source ut=div(|∇um|p−2∇ul+uq,  (x,t∈RN×(0,T, where N≥1, p>2 , and m, l,  q>1, and give a secondary critical exponent on the decay asymptotic behavior of an initial value at infinity for the existence and nonexistence of global solutions of the Cauchy problem. Moreover, under some suitable conditions we prove single-point blow-up for a large class of radial decreasing solutions.

  15. The near-source strong-motion accelerograms recorded by an experimental array in Tangshan, China

    Science.gov (United States)

    Peng, K.; Xie, Lingtian; Li, S.; Boore, D.M.; Iwan, W.D.; Teng, T.L.

    1985-01-01

    A joint research project on strong-motion earthquake studies between the People's Republic of China and the United States is in progress. As a part of this project, an experimental strong-motion array, consisting of twelve Kinemetrics PDR-1 Digital Event Recorders, was deployed in the meizoseismal area of the Ms = 7.8 Tangshan earthquake of July 28, 1976. These instruments have automatic gain ranging, a specified dynamic range of 102 dB, a 2.5 s pre-event memory, programmable triggering, and are equipped with TCG-1B Time Code Generators with a stability of 3 parts in 107 over a range of 0-50??C. In 2 y of operation beginning July, 1982 a total of 603 near-source 3-component accelerograms were gathered from 243 earthquakes of magnitude ML = 1.2-5.3. Most of these accelerograms have recorded the initial P-wave. The configuration of the experimental array and a representative set of near-source strong-motion accelerograms are presented in this paper. The set of accelerograms exhibited were obtained during the ML = 5.3 Lulong earthquake of October 19, 1982, when digital event recorders were triggered. The epicentral distances ranged from 4 to 41 km and the corresponding range of peak horizontal accelerations was 0.232g to 0.009g. A preliminary analysis of the data indicates that compared to motions in the western United States, the peak acceleration attenuates much more rapidly in the Tangshan area. The scaling of peak acceleration with magnitude, however, is similar in the two regions. Data at more distant sites are needed to confirm the more rapid attenuation. ?? 1985.

  16. Probing Motion of Fast Radio Burst Sources by Timing Strongly Lensed Repeaters

    Science.gov (United States)

    Dai, Liang; Lu, Wenbin

    2017-09-01

    Given the possible repetitive nature of fast radio bursts (FRBs), their cosmological origin, and their high occurrence, detection of strongly lensed sources due to intervening galaxy lenses is possible with forthcoming radio surveys. We show that if multiple images of a repeating source are resolved with VLBI, using a method independent of lens modeling, accurate timing could reveal non-uniform motion, either physical or apparent, of the emission spot. This can probe the physical nature of FRBs and their surrounding environments, constraining scenarios including orbital motion around a stellar companion if FRBs require a compact star in a special system, and jet-medium interactions for which the location of the emission spot may randomly vary. The high timing precision possible for FRBs (˜ms) compared with the typical time delays between images in galaxy lensing (≳10 days) enables the measurement of tiny fractional changes in the delays (˜ {10}-9) and hence the detection of time-delay variations induced by relative motions between the source, the lens, and the Earth. We show that uniform cosmic peculiar velocities only cause the delay time to drift linearly, and that the effect from the Earth’s orbital motion can be accurately subtracted, thus enabling a search for non-trivial source motion. For a timing accuracy of ˜1 ms and a repetition rate (of detected bursts) of ˜0.05 per day of a single FRB source, non-uniform displacement ≳0.1-1 au of the emission spot perpendicular to the line of sight is detectable if repetitions are seen over a period of hundreds of days.

  17. 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

  18. 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.

  19. Measurement of spatial and temporal evolution of electromagnetic fields in a 100 MHz plasma source using B dot and double dipole probes

    Energy Technology Data Exchange (ETDEWEB)

    Lane, Barton, E-mail: barton.lane@tel.com; Campbell, Colin; Sawada, Ikuo; Ventzek, Peter L. G., E-mail: peter.ventzek@tel.com [Tokyo Electron America, Inc., 2400 Grove Blvd., Austin, Texas 78741 (United States)

    2016-05-15

    Very high frequency plasma sources are often accompanied by plasma density nonuniformities associated with a standing-wave effect. Electron density measurements using a plasma absorption probe show density nonuniformities that can be larger than predicted by a standing wave model. These structures have been associated with harmonics of the electric fields in the plasma. The authors present the first time and phase-resolved measurements of the spatial structure of the electromagnetic waves in a 100 MHz plasma source using argon at 40 mTorr employing a B dot probe. The authors show that the harmonic structure is related to a current reversal and subsequent circulation that appears when the sheath collapses during the radio frequency cycle. The circulation is driven by inward traveling waves that are electromagnetic in nature, not plasma waves traveling at the electron thermal velocity. Double dipole probe measurements were used to validate the B dot probe electric field measurements derived from the time derivative of Β{sub θ} which is derived from the B dot probe signal.

  20. Adjoint Inversion for Extended Earthquake Source Kinematics From Very Dense Strong Motion Data

    Science.gov (United States)

    Ampuero, J. P.; Somala, S.; Lapusta, N.

    2010-12-01

    Addressing key open questions about earthquake dynamics requires a radical improvement of the robustness and resolution of seismic observations of large earthquakes. Proposals for a new generation of earthquake observation systems include the deployment of “community seismic networks” of low-cost accelerometers in urban areas and the extraction of strong ground motions from high-rate optical images of the Earth's surface recorded by a large space telescope in geostationary orbit. Both systems could deliver strong motion data with a spatial density orders of magnitude higher than current seismic networks. In particular, a “space seismometer” could sample the seismic wave field at a spatio-temporal resolution of 100 m, 1 Hz over areas several 100 km wide with an amplitude resolution of few cm/s in ground velocity. The amount of data to process would be immensely larger than what current extended source inversion algorithms can handle, which hampers the quantitative assessment of the cost-benefit trade-offs that can guide the practical design of the proposed earthquake observation systems. We report here on the development of a scalable source imaging technique based on iterative adjoint inversion and its application to the proof-of-concept of a space seismometer. We generated synthetic ground motions for M7 earthquake rupture scenarios based on dynamic rupture simulations on a vertical strike-slip fault embedded in an elastic half-space. A range of scenarios include increasing levels of complexity and interesting features such as supershear rupture speed. The resulting ground shaking is then processed accordingly to what would be captured by an optical satellite. Based on the resulting data, we perform source inversion by an adjoint/time-reversal method. The gradient of a cost function quantifying the waveform misfit between data and synthetics is efficiently obtained by applying the time-reversed ground velocity residuals as surface force sources, back

  1. The ALPS project release 2.0: open source software for strongly correlated systems

    International Nuclear Information System (INIS)

    Bauer, B; Gamper, L; Gukelberger, J; Hehn, A; Isakov, S V; Ma, P N; Mates, P; Carr, L D; Evertz, H G; Feiguin, A; Freire, J; Koop, D; Fuchs, S; Gull, E; Guertler, S; Igarashi, R; Matsuo, H; Parcollet, O; Pawłowski, G; Picon, J D

    2011-01-01

    We present release 2.0 of the ALPS (Algorithms and Libraries for Physics Simulations) project, an open source software project to develop libraries and application programs for the simulation of strongly correlated quantum lattice models such as quantum magnets, lattice bosons, and strongly correlated fermion systems. The code development is centered on common XML and HDF5 data formats, libraries to simplify and speed up code development, common evaluation and plotting tools, and simulation programs. The programs enable non-experts to start carrying out serial or parallel numerical simulations by providing basic implementations of the important algorithms for quantum lattice models: classical and quantum Monte Carlo (QMC) using non-local updates, extended ensemble simulations, exact and full diagonalization (ED), the density matrix renormalization group (DMRG) both in a static version and a dynamic time-evolving block decimation (TEBD) code, and quantum Monte Carlo solvers for dynamical mean field theory (DMFT). The ALPS libraries provide a powerful framework for programmers to develop their own applications, which, for instance, greatly simplify the steps of porting a serial code onto a parallel, distributed memory machine. Major changes in release 2.0 include the use of HDF5 for binary data, evaluation tools in Python, support for the Windows operating system, the use of CMake as build system and binary installation packages for Mac OS X and Windows, and integration with the VisTrails workflow provenance tool. The software is available from our web server at http://alps.comp-phys.org/

  2. Particle production in field theories coupled to strong external sources, I: Formalism and main results

    International Nuclear Information System (INIS)

    Gelis, Francois; Venugopalan, Raju

    2006-01-01

    We develop a formalism for particle production in a field theory coupled to a strong time-dependent external source. An example of such a theory is the color glass condensate. We derive a formula, in terms of cut vacuum-vacuum Feynman graphs, for the probability of producing a given number of particles. This formula is valid to all orders in the coupling constant. The distribution of multiplicities is non-Poissonian, even in the classical approximation. We investigate an alternative method of calculating the mean multiplicity. At leading order, the average multiplicity can be expressed in terms of retarded solutions of classical equations of motion. We demonstrate that the average multiplicity at next-to-leading order can be formulated as an initial value problem by solving equations of motion for small fluctuation fields with retarded boundary conditions. The variance of the distribution can be calculated in a similar fashion. Our formalism therefore provides a framework to compute from first principles particle production in proton-nucleus and nucleus-nucleus collisions beyond leading order in the coupling constant and to all orders in the source density. We also provide a transparent interpretation (in conventional field theory language) of the well-known Abramovsky-Gribov-Kancheli (AGK) cancellations. Explicit connections are made between the framework for multi-particle production developed here and the framework of reggeon field theory

  3. Source Rupture Process of the 2016 Kumamoto Prefecture, Japan, Earthquake Derived from Near-Source Strong-Motion Records

    Science.gov (United States)

    Zheng, A.; Zhang, W.

    2016-12-01

    On 15 April, 2016 the great earthquake with magnitude Mw7.1 occurred in Kumamoto prefecture, Japan. The focal mechanism solution released by F-net located the hypocenter at 130.7630°E, 32.7545°N, at a depth of 12.45 km, and the strike, dip, and the rake angle of the fault were N226°E, 84° and -142° respectively. The epicenter distribution and focal mechanisms of aftershocks implied the mechanism of the mainshock might have changed in the source rupture process, thus a single focal mechanism was not enough to explain the observed data adequately. In this study, based on the inversion result of GNSS and InSAR surface deformation with active structures for reference, we construct a finite fault model with focal mechanism changes, and derive the source rupture process by multi-time-window linear waveform inversion method using the strong-motion data (0.05 1.0Hz) obtained by K-NET and KiK-net of Japan. Our result shows that the Kumamoto earthquake is a right-lateral strike slipping rupture event along the Futagawa-Hinagu fault zone, and the seismogenic fault is divided into a northern segment and a southern one. The strike and the dip of the northern segment are N235°E, 60° respectively. And for the southern one, they are N205°E, 72° respectively. The depth range of the fault model is consistent with the depth distribution of aftershocks, and the slip on the fault plane mainly concentrate on the northern segment, in which the maximum slip is about 7.9 meter. The rupture process of the whole fault continues for approximately 18-sec, and the total seismic moment released is 5.47×1019N·m (Mw 7.1). In addition, the essential feature of the distribution of PGV and PGA synthesized by the inversion result is similar to that of observed PGA and seismic intensity.

  4. Source, propagation and site effects: impact on mapping strong ground motion in Bucharest area

    International Nuclear Information System (INIS)

    Radulian, R.; Kuznetsov, I.; Panza, G.F.

    2004-01-01

    Achievements in the framework of the NATO SfP project 972266 focused on the impact of Vrancea earthquakes on the security of Bucharest urban area are presented. The problem of Bucharest city security to Vrancea earthquakes is discussed in terms of numerical modelling of seismic motion and intermediate term earthquake prediction. A hybrid numerical scheme developed by Faeh et al. (1990; 1993) for frequencies up to 1 Hz is applied for the realistic modelling of the seismic ground motion in Bucharest. The method combines the modal summation for the 1D bedrock model and the finite differences for the 2D local structure model. All the factors controlling the ground motion at the site are considered: source, propagation and site effects, respectively. The input data includes the recent records provided by the digital accelerometer network developed within the Romanian-German CRC461 cooperation programme and CALIXTO'99, VRANCEA'99, VRANCEA2001 experiments. The numerical simulation proves to be a powerful tool in mapping the strong ground motion for realistic structures, reproducing acceptably from engineering point of view the observations. A new model of the Vrancea earthquake scaling is obtained and implications for the determination of the seismic motion parameters are analyzed. The role of the focal mechanism and attenuation properties upon the amplitude and spectral content of the ground motion are outlined. CN algorithm is applied for predicting Vrancea earthquakes. Finally, implications for the disaster management strategy are discussed. (authors)

  5. Source processes of strong earthquakes in the North Tien-Shan region

    Science.gov (United States)

    Kulikova, G.; Krueger, F.

    2013-12-01

    Tien-Shan region attracts attention of scientists worldwide due to its complexity and tectonic uniqueness. A series of very strong destructive earthquakes occurred in Tien-Shan at the turn of XIX and XX centuries. Such large intraplate earthquakes are rare in seismology, which increases the interest in the Tien-Shan region. The presented study focuses on the source processes of large earthquakes in Tien-Shan. The amount of seismic data is limited for those early times. In 1889, when a major earthquake has occurred in Tien-Shan, seismic instruments were installed in very few locations in the world and these analog records did not survive till nowadays. Although around a hundred seismic stations were operating at the beginning of XIX century worldwide, it is not always possible to get high quality analog seismograms. Digitizing seismograms is a very important step in the work with analog seismic records. While working with historical seismic records one has to take into account all the aspects and uncertainties of manual digitizing and the lack of accurate timing and instrument characteristics. In this study, we develop an easy-to-handle and fast digitization program on the basis of already existing software which allows to speed up digitizing process and to account for all the recoding system uncertainties. Owing to the lack of absolute timing for the historical earthquakes (due to the absence of a universal clock at that time), we used time differences between P and S phases to relocate the earthquakes in North Tien-Shan and the body-wave amplitudes to estimate their magnitudes. Combining our results with geological data, five earthquakes in North Tien-Shan were precisely relocated. The digitizing of records can introduce steps into the seismograms which makes restitution (removal of instrument response) undesirable. To avoid the restitution, we simulated historic seismograph recordings with given values for damping and free period of the respective instrument and

  6. Source Rupture Process of the 2016 Kumamoto, Japan, Earthquake Inverted from Strong-Motion Records

    Science.gov (United States)

    Zhang, Wenbo; Zheng, Ao

    2017-04-01

    On 15 April, 2016 the great earthquake with magnitude Mw7.1 occurred in Kumamoto prefecture, Japan. The focal mechanism solution released by F-net located the hypocenter at 130.7630°E, 32.7545°N, at a depth of 12.45 km, and the strike, dip, and the rake angle of the fault were N226°E, 84˚ and -142° respectively. The epicenter distribution and focal mechanisms of aftershocks implied the mechanism of the mainshock might have changed in the source rupture process, thus a single focal mechanism was not enough to explain the observed data adequately. In this study, based on the inversion result of GNSS and InSAR surface deformation with active structures for reference, we construct a finite fault model with focal mechanism changes, and derive the source rupture process by multi-time-window linear waveform inversion method using the strong-motion data (0.05 1.0Hz) obtained by K-NET and KiK-net of Japan. Our result shows that the Kumamoto earthquake is a right-lateral strike slipping rupture event along the Futagawa-Hinagu fault zone, and the seismogenic fault is divided into a northern segment and a southern one. The strike and the dip of the northern segment are N235°E, 60˚ respectively. And for the southern one, they are N205°E, 72˚ respectively. The depth range of the fault model is consistent with the depth distribution of aftershocks, and the slip on the fault plane mainly concentrate on the northern segment, in which the maximum slip is about 7.9 meter. The rupture process of the whole fault continues for approximately 18-sec, and the total seismic moment released is 5.47×1019N·m (Mw 7.1). In addition, the essential feature of the distribution of PGV and PGA synthesized by the inversion result is similar to that of observed PGA and seismic intensity.

  7. Preparation of a Strong Thin Polonium Source And Preliminary Experiments on the Yield of (α,n) Reactions

    International Nuclear Information System (INIS)

    Broda, E.

    1945-01-01

    This report was written by E. Broda and P. K. Wright at the Cavendish Laboratory (Cambridge) in July 1945 and is about the preparation of a strong thin polonium source and preliminary experiments on the yield of (alpha,n) reactions. This report includes the experiment description, the discussion of the results and consist of 4 parts: (1) the electrode position of polonium under different conditions (2) a standard procedure for preparation of strong thin Po sources (3) a simple method for the recovery of RaD from complex mixtures (4) some preliminary experiments with a Po source. (nowak)

  8. Preparation of a Strong Thin Polonium Source And Preliminary Experiments on the Yield of (α,n) Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Broda, E.

    1945-07-01

    This report was written by E. Broda and P. K. Wright at the Cavendish Laboratory (Cambridge) in July 1945 and is about the preparation of a strong thin polonium source and preliminary experiments on the yield of (alpha,n) reactions. This report includes the experiment description, the discussion of the results and consist of 4 parts: (1) the electrode position of polonium under different conditions (2) a standard procedure for preparation of strong thin Po sources (3) a simple method for the recovery of RaD from complex mixtures (4) some preliminary experiments with a Po source. (nowak)

  9. 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

  10. Electric dipole moment of the neutron in gauge theory

    International Nuclear Information System (INIS)

    Shabalin, E.P.

    1983-01-01

    One of the consequences of violation of CP invariance of the physical world is the existence of an electric dipole moment of elementary particles. The renormalization gauge theory of the electroweak and strong interactions developed during the past decade has revealed several possible sources of violation of CP invariance: direct violation of CP invariance in the Lagrangian of the electroweak interactions, spontaneous violation of CP invariance, and violation of CP invariance in the strong interactions described by quantum chromodynamics. The present review is devoted to a discussion of the predictions for the electric dipole moment of the neutron which follow from the various sources of violation of CP invariance in the theory. It includes the theoretical results obtained in the framework of gauge theory during the past decade up to the beginning of 1982. A comparison of the prediction of various gauge models with the experimental measurements of the electric dipole moment will make it possible to gain a better understanding of the nature of violation of CP invariance

  11. T violation in radiative β decay and electric dipole moments

    Directory of Open Access Journals (Sweden)

    W. Dekens

    2015-12-01

    Full Text Available In radiative β decay, T violation can be studied through a spin-independent T-odd correlation. We consider contributions to this correlation by beyond the standard model (BSM sources of T-violation, arising above the electroweak scale. At the same time such sources, parametrized by dimension-6 operators, can induce electric dipole moments (EDMs. As a consequence, the manifestations of the T-odd BSM physics in radiative β decay and EDMs are not independent. Here we exploit this connection to show that current EDM bounds already strongly constrain the spin-independent T-odd correlation in radiative β decay.

  12. T violation in radiative β decay and electric dipole moments

    Energy Technology Data Exchange (ETDEWEB)

    Dekens, W.; Vos, K.K., E-mail: k.k.vos@rug.nl

    2015-12-17

    In radiative β decay, T violation can be studied through a spin-independent T-odd correlation. We consider contributions to this correlation by beyond the standard model (BSM) sources of T-violation, arising above the electroweak scale. At the same time such sources, parametrized by dimension-6 operators, can induce electric dipole moments (EDMs). As a consequence, the manifestations of the T-odd BSM physics in radiative β decay and EDMs are not independent. Here we exploit this connection to show that current EDM bounds already strongly constrain the spin-independent T-odd correlation in radiative β decay.

  13. 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...

  14. A strongly heated neutron star in the transient z source MAXI J0556-332

    Energy Technology Data Exchange (ETDEWEB)

    Homan, Jeroen; Remillard, Ronald A. [MIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue 37-582D, Cambridge, MA 02139 (United States); Fridriksson, Joel K.; Wijnands, Rudy [Anton Pannekoek Institute for Astronomy, University of Amsterdam, Postbus 94249, 1090 GE Amsterdam (Netherlands); Cackett, Edward M. [Department of Physics and Astronomy, Wayne State University, 666 W. Hancock St., Detroit, MI 48201 (United States); Degenaar, Nathalie [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Linares, Manuel [Instituto de Astrofísica de Canarias, c/ Vía Láctea s/n, E-38205 La Laguna, Tenerife (Spain); Lin, Dacheng, E-mail: jeroen@space.mit.edu [Space Science Center, University of New Hampshire, Durham, NH 03824 (United States)

    2014-11-10

    We present Chandra, XMM-Newton, and Swift observations of the quiescent neutron star in the transient low-mass X-ray binary MAXI J0556-332. Observations of the source made during outburst (with the Rossi X-ray Timing Explorer) reveal tracks in its X-ray color-color and hardness-intensity diagrams that closely resemble those of the neutron-star Z sources, suggesting that MAXI J0556-332 had near- or super-Eddington luminosities for a large part of its ∼16 month outburst. A comparison of these diagrams with those of other Z sources suggests a source distance of 46 ± 15 kpc. Fits to the quiescent spectra of MAXI J0556-332 with a neutron-star atmosphere model (with or without a power-law component) result in distance estimates of 45 ± 3 kpc, for a neutron-star radius of 10 km and a mass of 1.4 M {sub ☉}. The spectra show the effective surface temperature of the neutron star decreasing monotonically over the first ∼500 days of quiescence, except for two observations that were likely affected by enhanced low-level accretion. The temperatures we obtain for the fits that include a power law (kT{sub eff}{sup ∞} = 184-308 eV) are much higher than those seen for any other neutron star heated by accretion, while the inferred cooling (e-folding) timescale (∼200 days) is similar to other sources. Fits without a power law yield higher temperatures (kT{sub eff}{sup ∞} = 190-336 eV) and a shorter e-folding time (∼160 days). Our results suggest that the heating of the neutron-star crust in MAXI J0556-332 was considerably more efficient than for other systems, possibly indicating additional or more efficient shallow heat sources in its crust.

  15. 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)

  16. 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...

  17. The deflection angle of a gravitational source with a global monopole in the strong field limit

    International Nuclear Information System (INIS)

    Cheng Hongbo; Man Jingyun

    2011-01-01

    We investigate the gravitational lensing effect in the strong field background around the Schwarzschild black hole with extremely small mass and solid deficit angle subject to the global monopole by means of the strong field limit issue. We obtain the angular position and magnification of the relativistic images and show that they relate to the global monopole parameter η. We discuss that with the increase of the parameter η, the minimum impact parameter u m and angular separation s increase and the relative magnification r decreases. We also find that s grows extremely as the increasing parameter η becomes large enough. The deflection angle will become larger when the parameter η grows. The effect from the solid deficit angle is the dependence of angular position, angular separation, relative magnification and deflection angle on the parameter η, which may offer a way to characterize some possible distinct signatures of the Schwarzschild black hole with a solid deficit angle associated with the global monopole.

  18. A comparison of two methods for earthquake source inversion using strong motion seismograms

    Directory of Open Access Journals (Sweden)

    G. C. Beroza

    1994-06-01

    Full Text Available In this paper we compare two time-domain inversion methods that have been widely applied to the problem of modeling earthquake rupture using strong-motion seismograms. In the multi-window method, each point on the fault is allowed to rupture multiple times. This allows flexibility in the rupture time and hence the rupture velocity. Variations in the slip-velocity function are accommodated by variations in the slip amplitude in each time-window. The single-window method assumes that each point on the fault ruptures only once, when the rupture front passes. Variations in slip amplitude are allowed and variations in rupture velocity are accommodated by allowing the rupture time to vary. Because the multi-window method allows greater flexibility, it has the potential to describe a wider range of faulting behavior; however, with this increased flexibility comes an increase in the degrees of freedom and the solutions are comparatively less stable. We demonstrate this effect using synthetic data for a test model of the Mw 7.3 1992 Landers, California earthquake, and then apply both inversion methods to the actual recordings. The two approaches yield similar fits to the strong-motion data with different seismic moments indicating that the moment is not well constrained by strong-motion data alone. The slip amplitude distribution is similar using either approach, but important differences exist in the rupture propagation models. The single-window method does a better job of recovering the true seismic moment and the average rupture velocity. The multi-window method is preferable when rise time is strongly variable, but tends to overestimate the seismic moment. Both methods work well when the rise time is constant or short compared to the periods modeled. Neither approach can recover the temporal details of rupture propagation unless the distribution of slip amplitude is constrained by independent data.

  19. 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

  20. Strong neutron sources - How to cope with weapon material production capabilities of fusion and spallation neutron sources?

    International Nuclear Information System (INIS)

    Englert, M.; Franceschini, G.; Liebert, W.

    2013-01-01

    In this article we investigate the potential and relevance for weapon material production in future fusion power plants and spallation neutron sources (SNS) and sketch what should be done to strengthen these technologies against a non-peaceful use. It is shown that future commercial fusion reactors may have military implications: first, they provide an easy source of tritium for weapons, an element that does not fall under safeguards and for which diversion from a plant could probably not be detected even if some tritium accountancy is implemented. Secondly, large fusion reactors - even if not designed for fissile material breeding - could easily produce several hundred kg Pu per year with high weapon quality and very low source material requirements. If fusion-only reactors will prevail over fission-fusion hybrids in the commercialization phase of fusion technology, the safeguard challenge will be more of a legal than of a technical nature. In pure fusion reactors (and in most SNS) there should be no nuclear material present at any time by design. The presence of undeclared nuclear material would indicate a military use of the plant. This fact offers a clear-cut detection criterion for a covert use of a declared facility. Another important point is that tritium does not fall under the definition of 'nuclear material', so a pure fusion reactor or a SNS that do not use nuclear materials are not directly falling under any international non-proliferation treaty requirements. Non-proliferation treaties have to be amended to take into account that fact. (A.C.)

  1. 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.

  2. Natural plant sugar sources of Anopheles mosquitoes strongly impact malaria transmission potential.

    Directory of Open Access Journals (Sweden)

    Weidong Gu

    Full Text Available An improved knowledge of mosquito life history could strengthen malaria vector control efforts that primarily focus on killing mosquitoes indoors using insecticide treated nets and indoor residual spraying. Natural sugar sources, usually floral nectars of plants, are a primary energy resource for adult mosquitoes but their role in regulating the dynamics of mosquito populations is unclear. To determine how the sugar availability impacts Anopheles sergentii populations, mark-release-recapture studies were conducted in two oases in Israel with either absence or presence of the local primary sugar source, flowering Acacia raddiana trees. Compared with population estimates from the sugar-rich oasis, An. sergentii in the sugar-poor oasis showed smaller population size (37,494 vs. 85,595, lower survival rates (0.72 vs. 0.93, and prolonged gonotrophic cycles (3.33 vs. 2.36 days. The estimated number of females older than the extrinsic incubation period of malaria (10 days in the sugar rich site was 4 times greater than in the sugar poor site. Sugar feeding detected in mosquito guts in the sugar-rich site was significantly higher (73% than in the sugar-poor site (48%. In contrast, plant tissue feeding (poor quality sugar source in the sugar-rich habitat was much less (0.3% than in the sugar-poor site (30%. More important, the estimated vectorial capacity, a standard measure of malaria transmission potential, was more than 250-fold higher in the sugar-rich oasis than that in the sugar-poor site. Our results convincingly show that the availability of sugar sources in the local environment is a major determinant regulating the dynamics of mosquito populations and their vector potential, suggesting that control interventions targeting sugar-feeding mosquitoes pose a promising tactic for combating transmission of malaria parasites and other pathogens.

  3. 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.

  4. 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.

  5. Bright broadband coherent fiber sources emitting strongly blue-shifted resonant dispersive wave pulses

    DEFF Research Database (Denmark)

    Tu, Haohua; Lægsgaard, Jesper; Zhang, Rui

    2013-01-01

    We predict and realize the targeted wavelength conversion from the 1550-nm band of a fs Er:fiber laser to an isolated band inside 370-850 nm, corresponding to a blue-shift of 700-1180 nm. The conversion utilizes resonant dispersive wave generation in widely available optical fibers with good...... efficiency (~7%). The converted band has a large pulse energy (~1 nJ), high spectral brightness (~1 mW/nm), and broad Gaussian-like spectrum compressible to clean transform-limited ~17 fs pulses. The corresponding coherent fiber sources open up portable applications of optical parametric oscillators and dual......-output synchronized ultrafast lasers....

  6. Measurements of strongly localized potential well profiles in an inertial electrostatic fusion neutron source

    International Nuclear Information System (INIS)

    Yoshikawa, K.; Takiyama, K.; Koyama, T.

    2001-01-01

    Direct measurements of localized electric fields are made by the laser-induced fluorescence (LIF) method by use of the Stark effects in the central cathode core region of an Inertial-Electrostatic Confinement Fusion (IECF) neutron (proton) source, which is expected for various applications, such as luggage security inspection, non-destructive testing, land mine detector, or positron emitter production for cancer detection, currently producing continuously about 10 7 n/sec D-D neutrons. Since 1967 when the first fusion reaction was successfully proved experimentally in a very compact IECF device, potential well formation due to space charge associated with spherically converging ion beams has been a central key issue to be clarified in the beam-beam colliding fusion, which is the major mechanism of the IECF neutron source. Many experiments, but indirect, were made so far to clarify the potential well, but none of them produced definitive evidence, however. Results by the present LIF method show a double well potential profile with a slight concave for ion beams with relatively larger angular momenta, whereas for ions with smaller angular momenta, potential but much steeper peak to develop. (author)

  7. 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

  8. Compact X-ray sources. Simulating the electron/strong laser interaction

    Energy Technology Data Exchange (ETDEWEB)

    Hartin, Anthony [DESY, CFEL, Hamburg (Germany)

    2016-07-01

    The collision of an intense laser with an electron bunch can be used to produce X-rays via the inverse Compton scattering (ICS) mechanism. The ICS can be simulated via either a classical theory in which electrons and photons are treated in terms of classical electromagnetic waves - or a quantum theory in which charged particles interact with strong electromagnetic fields. The laser intensity used in a practical ICS collision is likely to be at such a level that quantum effects may be significant and the use of quantum theory may become a necessity. A simulation study is presented here comparing the classical and quantum approaches to the ICS. A custom particle-in-cell (PIC) software code, with photon generation by monte carlo of the exact quantum transition probability is used to simulate the quantum treatment. Peak resonant energies and the angular distribution of the X-rays are obtained and compared with those predicted by the classical theory. The conditions under which significant differences between the two theories emerges is obtained.

  9. Can a Hexapole magnet of an ECR Ion Source be too strong?

    CERN Document Server

    Drentje, A G; Kremers, H R; Meyer, D; Mulder, J; Sijbring, J

    1999-01-01

    Experience of many ECRIS designers and users during more than a decade has given a few experimental rules, or "scaling laws". Many of these have been discussed at the ECRIS workshops. After the 1993 workshop it was concluded that the properties of the magnetic trap, in particular the strength of the radial component, determine to a great deal the confinement characteristics. For that reason it was decided at the KVI to choose a very strong magnet for the new 14 GHz ECRIS4 to be used in the Atomic Physics experiments. The hexapole magnet designed by the Giessen group is a good example. The induction, measured 2.5 mm inside the pole tips (i.e. at the wall of the plasma chamber) amounts more than 1.2 T. The measured radial field component Br obeys closely the expression Br= 0.00136 r2. (with B in T, r in mm). The quality of the magnetic trap can be given by the "radial mirror ratio", which is usually defined as R = Bmax / Breson, with Breson equal 0.5 T for a 14 GHz ECRIS. For the KVI magnet this would give R= 2...

  10. 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.

  11. 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.

  12. The SCEC Broadband Platform: Open-Source Software for Strong Ground Motion Simulation and Validation

    Science.gov (United States)

    Silva, F.; Goulet, C. A.; Maechling, P. J.; Callaghan, S.; Jordan, T. H.

    2016-12-01

    The Southern California Earthquake Center (SCEC) Broadband Platform (BBP) is a carefully integrated collection of open-source scientific software programs that can simulate broadband (0-100 Hz) ground motions for earthquakes at regional scales. The BBP can run earthquake rupture and wave propagation modeling software to simulate ground motions for well-observed historical earthquakes and to quantify how well the simulated broadband seismograms match the observed seismograms. The BBP can also run simulations for hypothetical earthquakes. In this case, users input an earthquake location and magnitude description, a list of station locations, and a 1D velocity model for the region of interest, and the BBP software then calculates ground motions for the specified stations. The BBP scientific software modules implement kinematic rupture generation, low- and high-frequency seismogram synthesis using wave propagation through 1D layered velocity structures, several ground motion intensity measure calculations, and various ground motion goodness-of-fit tools. These modules are integrated into a software system that provides user-defined, repeatable, calculation of ground-motion seismograms, using multiple alternative ground motion simulation methods, and software utilities to generate tables, plots, and maps. The BBP has been developed over the last five years in a collaborative project involving geoscientists, earthquake engineers, graduate students, and SCEC scientific software developers. The SCEC BBP software released in 2016 can be compiled and run on recent Linux and Mac OS X systems with GNU compilers. It includes five simulation methods, seven simulation regions covering California, Japan, and Eastern North America, and the ability to compare simulation results against empirical ground motion models (aka GMPEs). The latest version includes updated ground motion simulation methods, a suite of new validation metrics and a simplified command line user interface.

  13. 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.

  14. 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....

  15. 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)

  16. Quantification of Greenhouse Gas Emission Rates from strong Point Sources by Airborne IPDA-Lidar Measurements: Methodology and Experimental Results

    Science.gov (United States)

    Ehret, G.; Amediek, A.; Wirth, M.; Fix, A.; Kiemle, C.; Quatrevalet, M.

    2016-12-01

    We report on a new method and on the first demonstration to quantify emission rates from strong greenhouse gas (GHG) point sources using airborne Integrated Path Differential Absorption (IPDA) Lidar measurements. In order to build trust in the self-reported emission rates by countries, verification against independent monitoring systems is a prerequisite to check the reported budget. A significant fraction of the total anthropogenic emission of CO2 and CH4 originates from localized strong point sources of large energy production sites or landfills. Both are not monitored with sufficiently accuracy by the current observation system. There is a debate whether airborne remote sensing could fill in the gap to infer those emission rates from budgeting or from Gaussian plume inversion approaches, whereby measurements of the GHG column abundance beneath the aircraft can be used to constrain inverse models. In contrast to passive sensors, the use of an active instrument like CHARM-F for such emission verification measurements is new. CHARM-F is a new airborne IPDA-Lidar devised for the German research aircraft HALO for the simultaneous measurement of the column-integrated dry-air mixing ratio of CO2 and CH4 commonly denoted as XCO2 und XCH4, respectively. It has successfully been tested in a serious of flights over Central Europe to assess its performance under various reflectivity conditions and in a strongly varying topography like the Alps. The analysis of a methane plume measured in crosswind direction of a coal mine ventilation shaft revealed an instantaneous emission rate of 9.9 ± 1.7 kt CH4 yr-1. We discuss the methodology of our point source estimation approach and give an outlook on the CoMet field experiment scheduled in 2017 for the measurement of anthropogenic and natural GHG emissions by a combination of active and passive remote sensing instruments on research aircraft.

  17. 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...

  18. The contribution of Diamond Light Source to the study of strongly correlated electron systems and complex magnetic structures.

    Science.gov (United States)

    Radaelli, P G; Dhesi, S S

    2015-03-06

    We review some of the significant contributions to the field of strongly correlated materials and complex magnets, arising from experiments performed at the Diamond Light Source (Harwell Science and Innovation Campus, Didcot, UK) during the first few years of operation (2007-2014). We provide a comprehensive overview of Diamond research on topological insulators, multiferroics, complex oxides and magnetic nanostructures. Several experiments on ultrafast dynamics, magnetic imaging, photoemission electron microscopy, soft X-ray holography and resonant magnetic hard and soft X-ray scattering are described. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  19. 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.

  20. 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

  1. 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.)

  2. 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.)

  3. 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)

  4. 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

  5. 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.

  6. Strong-motion characteristics and source process during the Suruga Bay earthquake in 2009 through observed records on rock sites

    International Nuclear Information System (INIS)

    Shiba, Yoshiaki; Sato, Hiroaki; Kuriyama, Masayuki

    2010-01-01

    On 11 August 2009, a moderate earthquake of M 6.5 occurred in the Suruga Bay region, south of Shizuoka prefecture. During this event, JMA Seismic Intensity reached 6 lower in several cities around the hypocenter, and at Hamaoka nuclear power plant of Chubu Electric Power reactors were automatically shutdown due to large ground motions. Though the epicenter is located at the eastern edge of source area for the assumed great Tokai earthquake of M 8, this event is classified into the intra-plate (intra-slab) earthquake, due to its focal depth lower than that of the plate boundary and fault geometry supposed from the moment tensor solution. Dense strong-motion observation network has been deployed mainly on the rock outcrops by our institute around the source area, and the waveform data of the main shock and several aftershocks were obtained at 13 stations within 100 km from the hypocenter. The observed peak ground motions and velocity response spectral amplitudes are both obviously larger than the empirical attenuation relations derived from the inland and plate-boundary earthquake data, which displays the characteristics of the intra-slab earthquake faulting. Estimated acceleration source spectra of the main shock also exhibit the short period level about 1.7 times larger than the average of those for past events, and it corresponds with the additional term in the attenuation curve of the peak ground acceleration for the intra-plate earthquake. Detailed source process of the main shock is inferred using the inversion technique. The initial source model is assumed to be composed of two distinct fault planes according to the minute aftershock distribution. Estimated source model shows that large slip occurred near the hypocenter and at the boundary region between two fault planes where the rupture transfers from primary to secondary fault. Furthermore the broadband source inversion using velocity motions in the frequency up to 5 Hz demonstrates the high effective

  7. 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.)

  8. 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.

  9. 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

  10. 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.

  11. Substorm onset location and dipole tilt angle

    Directory of Open Access Journals (Sweden)

    J. Wanliss

    2006-03-01

    Full Text Available From an initial data set of over 200 substorms we have studied a subset of 30 magnetospheric substorms close to magnetic midnight to investigate, in a statistical fashion, the source region of the auroral arc that brightens at the onset of expansive phase. This arc is usually identified as the ionospheric signature of the expansive phase onset that occurs in the magnetotail. All the substorm onsets were identified via ground-based magnetometer and photometer data from the CANOPUS array. Various Tsyganenko global magnetic field models were used to map magnetic field lines from the location of the onset arc out to its greatest radial distance in the magnetotail. The results appear to favour the current disruption model of substorms since the average onset location has an average of 14.1 Earth radii (RE and is therefore more consistent with theories that place the onset location in the inner magnetotail. For the narrow range of tilts available our modeling indicates the parameter that appears to strongly influence the location of the substorm onset is the dipole tilt angle; as tilt becomes less negative onsets occur further downtail.

  12. 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.

  13. 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.

  14. 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)

  15. 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.

  16. 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.

  17. 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.)

  18. 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.)

  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. 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

  1. 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).

  2. Atom collisions in a strong electromagnetic field

    International Nuclear Information System (INIS)

    Smirnov, V.S.; Chaplik, A.V.

    1976-01-01

    It is shown that the long-range part of interatomic interaction is considerably altered in a strong electromagnetic field. Instead of the van der Waals law the potential asymptote can best be described by a dipole-dipole R -3 law. Impact broadening and the line shift in a strong nonresonant field are calculated. The possibility of bound states of two atoms being formed in a strong light field is discussed

  3. Electric dipole moments in two-Higgs-doublet models

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Martin [Institut für Physik, Technische Universität Dortmund,Otto-Hahn-Str. 4, D-44221 Dortmund (Germany); Pich, Antonio [IFIC, Universitat de València - CSIC,Apt. Correos 22085, E-46071 València (Spain)

    2014-04-10

    Electric dipole moments are extremely sensitive probes for additional sources of CP violation in new physics models. Specifically, they have been argued in the past to exclude new CP-violating phases in two-Higgs-doublet models. Since recently models including such phases have been discussed widely, we revisit the available constraints in the presence of mechanisms which are typically invoked to evade flavour-changing neutral currents. To that aim, we start by assessing the necessary calculations on the hadronic, nuclear and atomic/molecular level, deriving expressions with conservative error estimates. Their phenomenological analysis in the context of two-Higgs-doublet models yields strong constraints, in some cases weakened by a cancellation mechanism among contributions from neutral scalars. While the corresponding parameter combinations do not yet have to be unnaturally small, the constraints are likely to preclude large effects in other CP-violating observables. Nevertheless, the generically expected contributions to electric dipole moments in this class of models lie within the projected sensitivity of the next-generation experiments.

  4. 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.

  5. 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.

  6. 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.

  7. 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...

  8. 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

  9. 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...

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. Runaway breakdown in strong electric field as a source of terrestrial gamma flashes and gamma bursts in lightning leader steps

    Energy Technology Data Exchange (ETDEWEB)

    Gurevich, A.V. [P.N. Lebedev Physical Institute, Russian Academy of Sciences, 119991 Moscow (Russian Federation)]. E-mail: alex@lpi.ru; Zybin, K.P. [P.N. Lebedev Physical Institute, Russian Academy of Sciences, 119991 Moscow (Russian Federation); Medvedev, Yu.V. [Joint Institute for High Temperature, Russian Academy of Sciences, 127412 Moscow (Russian Federation)

    2007-01-22

    The new model of lightning step leader is proposed. It includes three main processes developing simultaneously in a strong electric field: conventional breakdown, effect of runaway electrons and runaway breakdown (RB). The theory of RB in strong electric field is developed. Comparison with the existing observational data shows that the model can serve as a background for the explanation of gamma bursts in step leader and TGF.

  16. Runaway breakdown in strong electric field as a source of terrestrial gamma flashes and gamma bursts in lightning leader steps

    International Nuclear Information System (INIS)

    Gurevich, A.V.; Zybin, K.P.; Medvedev, Yu.V.

    2007-01-01

    The new model of lightning step leader is proposed. It includes three main processes developing simultaneously in a strong electric field: conventional breakdown, effect of runaway electrons and runaway breakdown (RB). The theory of RB in strong electric field is developed. Comparison with the existing observational data shows that the model can serve as a background for the explanation of gamma bursts in step leader and TGF

  17. Quantitative analysis on electric dipole energy in Rashba band splitting.

    Science.gov (United States)

    Hong, Jisook; Rhim, Jun-Won; Kim, Changyoung; Ryong Park, Seung; Hoon Shim, Ji

    2015-09-01

    We report on quantitative comparison between the electric dipole energy and the Rashba band splitting in model systems of Bi and Sb triangular monolayers under a perpendicular electric field. We used both first-principles and tight binding calculations on p-orbitals with spin-orbit coupling. First-principles calculation shows Rashba band splitting in both systems. It also shows asymmetric charge distributions in the Rashba split bands which are induced by the orbital angular momentum. We calculated the electric dipole energies from coupling of the asymmetric charge distribution and external electric field, and compared it to the Rashba splitting. Remarkably, the total split energy is found to come mostly from the difference in the electric dipole energy for both Bi and Sb systems. A perturbative approach for long wave length limit starting from tight binding calculation also supports that the Rashba band splitting originates mostly from the electric dipole energy difference in the strong atomic spin-orbit coupling regime.

  18. On the nature of the Madagascar dipoles: An analysis from Argo profiling floats and altimetry measurements

    Science.gov (United States)

    Aguiar-González, Borja; Ponsoni, Leandro; Ridderinkhof, Herman; de Ruijter, Will P. M.; Maas, Leo R. M.

    2016-04-01

    The South East Madagascar Current (SEMC) flows poleward along the eastern coast of Madagascar as a western boundary current which further south provides some of the source waters of the Agulhas Current, either directly or in the form of eddies. We investigate the region of dipole formation south of Madagascar combining vertical T/S profiles from Argo floats, altimetry measurements and an existing eddy detection algorithm. Results from our analysis show that the dipole consists of an anticyclonic intrathermocline eddy (ITE) formed on its southern flank and a cyclonic ITE formed on its northern flank. Both lobes of the dipole exhibit similar T/S properties throughout the water column, although vertically shifted within the thermocline depending on its nature: upward in a cyclonic ITE and downward in an anticyclonic ITE. A subsurface salinity maximum of about 35.5 psu characterizes the upper layers with Subtropical Surface Water (STSW). At intermediate levels, a well defined path of South Indian Central Water (SICW) extends throughout the water column up to reach a minimum in salinity of 34.5 psu, corresponding to Antarctic Intermediate Water (AAIW). Below, at deep layers, the North Atlantic Deep Water (NADW) is found. The intrathermocline nature of the Madagascar dipoles has not been previously reported and represents an important feature to be considered when assessing the heat and salt fluxes driven by eddy movement and contributing to the Agulhas Current. Unlike surface eddies, intrathermocline eddies strongly influence the intermediate/deeper layers in the oceans and, hence, may have a larger contribution in the spreading rates and pathways of water masses. Because the intrathermocline nature of eddies is invisible to altimetry measurements, these results stress the importance of combining altimetry with historical records of Argo profiles which uncover eddy dynamics below the sea surface. Lastly, we further investigate from altimetry the area of dipole formation

  19. 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

  20. 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

  1. Active cancellation of probing in linear dipole phased array

    CERN Document Server

    Singh, Hema; Jha, Rakesh Mohan

    2015-01-01

    In this book, a modified improved LMS algorithm is employed for weight adaptation of dipole array for the generation of beam pattern in multiple signal environments. In phased arrays, the generation of adapted pattern according to the signal scenario requires an efficient adaptive algorithm. The antenna array is expected to maintain sufficient gain towards each of the desired source while at the same time suppress the probing sources. This cancels the signal transmission towards each of the hostile probing sources leading to active cancellation. In the book, the performance of dipole phased array is demonstrated in terms of fast convergence, output noise power and output signal-to-interference-and noise ratio. The mutual coupling effect and role of edge elements are taken into account. It is established that dipole array along with an efficient algorithm is able to maintain multilobe beamforming with accurate and deep nulls towards each probing source. This work has application to the active radar cross secti...

  2. Differentiating weak ties and strong ties among external sources of influences for enterprise resource planning (ERP) adoption

    Science.gov (United States)

    Aubert, Benoit; Léger, Pierre-Majorique; Larocque, Denis

    2012-05-01

    Enterprise resource planning (ERP) systems represent a major IT adoption decision. ERP adoption decisions, in the chemicals and allied products sectors, were examined between 1994 and 2005. Networks of strong ties and weak ties partners are investigated. Results show that neighbouring companies linked with strong ties can have an influence on organisations making such adoption decision. Past decisions made by major trading partners have a significant influence on the decision to adopt an ERP system for a given organisation. This reflects the complex nature of the knowledge required for such adoption.

  3. Comparison of electric dipole and magnetic dipole models for electromagnetic pulse generated by nuclear detonation in space

    International Nuclear Information System (INIS)

    Zhu Meng; Zhou Hui; Cheng Yinhui; Li Baozhong; Wu Wei; Li Jinxi; Ma Liang; Zhao Mo

    2013-01-01

    Electromagnetic pulse can be generated by the nuclear detonation in space via two radiation mechanisms. The electric dipole and magnetic dipole models were analyzed. The electric radiation in the far field generated by two models was calculated as well. Investigations show that in the case of one hundred TNT yield detonations, when electrons are emitted according to the Gaussian shape, two radiation models can give rise to the electric field in great distances with amplitudes of kV/m and tens of V/m, independently. Because the geomagnetic field in space is not strong and the electrons' angular motion is much weaker than the motion in the original direction, radiations from the magnetic dipole model are much weaker than those from the electric dipole model. (authors)

  4. He leak testing of Indus-2 dipole vacuum chambers

    International Nuclear Information System (INIS)

    Sindal, B.K.; Bhavsar, S.T.; Shukla, S.K.

    2003-01-01

    Full text: Centre for Advanced Technology is developing its second synchrotron radiation source INDUS-2 which is a 2.5 GeV electron storage ring. Dipole vacuum chambers are the vital components of Indus-2 vacuum system. Each of these chambers is approx. 3.6 m long and 0.67 m wide with 24 nos. of ports of various sizes. The dipole chambers were made by machining two halves and they are then lip welded together. The dipole chamber has approx. 14 m of total weld length and it was leak tested for leak tightness of the order of 10 -10 mbar 1/s. Helium mass spectrometer leak detector (HMSLD) was utilized for the leak testing. Subsequently the leaks of various orders in welding joints were repaired and leak tightness achieved. This paper describes the experiences during leak testing of 20 nos. of aluminum dipole chambers for INDUS-2

  5. 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.

  6. A Catalogue of Source Parameters of Moderate and Strong Earthquakes for Turkey and its Surrounding Area (1938-2015)

    Science.gov (United States)

    Kalafat, D.; Toksoz, M. N.

    2015-12-01

    Turkey and Surrounding area, especially North Anatolian Fault Zone (NAFZ), East Anatolian Fault Zone (EAFZ), Western Turkey, cost of the Aegean Sea and Mediterranean Sea regions are seismically very active and undergoing rapid deformation. Earthquakes with M >6.0 do occur every couple of years regularly in this region, Moderate-magnitude seismicity (4.04.0 which were calculated of the fault-source parameters for Turkey and its surrounding area between 1938-2015. The fault source parameters of total over the 1200 earthquakes were calculated. The fault-source parameters of about 56.0 % of the all events were calculated with this study and 44.0 % of the rest were obtained from the other sources. The parameters of the old and incomplete events also were calculated in order to prepare the homogeneous and extended fault- source parameters set in the study. ACKNOWLEDGMENTS This study was supported by the Department of Science Fellowship and Grant programs of TUBITAK (The Scientific and Technological Research Council of Turkey).

  7. A semi-empirical analysis of strong-motion peaks in terms of seismic source, propagation path, and local site conditions

    Science.gov (United States)

    Kamiyama, M.; Orourke, M. J.; Flores-Berrones, R.

    1992-09-01

    A new type of semi-empirical expression for scaling strong-motion peaks in terms of seismic source, propagation path, and local site conditions is derived. Peak acceleration, peak velocity, and peak displacement are analyzed in a similar fashion because they are interrelated. However, emphasis is placed on the peak velocity which is a key ground motion parameter for lifeline earthquake engineering studies. With the help of seismic source theories, the semi-empirical model is derived using strong motions obtained in Japan. In the derivation, statistical considerations are used in the selection of the model itself and the model parameters. Earthquake magnitude M and hypocentral distance r are selected as independent variables and the dummy variables are introduced to identify the amplification factor due to individual local site conditions. The resulting semi-empirical expressions for the peak acceleration, velocity, and displacement are then compared with strong-motion data observed during three earthquakes in the U.S. and Mexico.

  8. High-frequency source radiation during the 2011 Tohoku-Oki earthquake, Japan, inferred from KiK-net strong-motion seismograms

    Science.gov (United States)

    Kumagai, Hiroyuki; Pulido, Nelson; Fukuyama, Eiichi; Aoi, Shin

    2013-01-01

    investigate source processes of the 2011 Tohoku-Oki earthquake, we utilized a source location method using high-frequency (5-10 Hz) seismic amplitudes. In this method, we assumed far-field isotropic radiation of S waves, and conducted a spatial grid search to find the best fitting source locations along the subducted slab in each successive time window. Our application of the method to the Tohoku-Oki earthquake resulted in artifact source locations at shallow depths near the trench caused by limited station coverage and noise effects. We then assumed various source node distributions along the plate, and found that the observed seismograms were most reasonably explained when assuming deep source nodes. This result suggests that the high-frequency seismic waves were radiated at deeper depths during the earthquake, a feature which is consistent with results obtained from teleseismic back-projection and strong-motion source model studies. We identified three high-frequency subevents, and compared them with the moment-rate function estimated from low-frequency seismograms. Our comparison indicated that no significant moment release occurred during the first high-frequency subevent and the largest moment-release pulse occurred almost simultaneously with the second high-frequency subevent. We speculated that the initial slow rupture propagated bilaterally from the hypocenter toward the land and trench. The landward subshear rupture propagation consisted of three successive high-frequency subevents. The trenchward propagation ruptured the strong asperity and released the largest moment near the trench.

  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. Strong Maximum Principle for Multi-Term Time-Fractional Diffusion Equations and its Application to an Inverse Source Problem

    OpenAIRE

    Liu, Yikan

    2015-01-01

    In this paper, we establish a strong maximum principle for fractional diffusion equations with multiple Caputo derivatives in time, and investigate a related inverse problem of practical importance. Exploiting the solution properties and the involved multinomial Mittag-Leffler functions, we improve the weak maximum principle for the multi-term time-fractional diffusion equation to a stronger one, which is parallel to that for its single-term counterpart as expected. As a direct application, w...

  11. Electromagnetic fields of ionospheric point dipoles in the earthionosphere waveguide

    International Nuclear Information System (INIS)

    Rybachek, S.T.

    1985-01-01

    This paper addresses the problem of excitation of the spherical earth-anisotropic ionosphere waveguide by ionospheric dipole sources. The solution obtained is based on a generalized reciprocity theorem which provides a relationship to the problem of finding electromagnetic fields in the ionosphere created by sources located in the waveguide. Some results of the calculations are presented

  12. 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

  13. 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.

  14. 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

  15. On the source of the dust extinction in type Ia supernovae and the discovery of anomalously strong Na I absorption

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, M. M.; Morrell, Nidia; Hsiao, E. Y.; Campillay, Abdo; Contreras, Carlos [Carnegie Observatories, Las Campanas Observatory, Casilla 601, La Serena (Chile); Simon, Joshua D.; Burns, Christopher R.; Persson, Sven E.; Thompson, I. B.; Freedman, Wendy L. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara St., Pasadena, CA 91101 (United States); Cox, Nick L. J. [Instituut voor Sterrenkunde, KU Leuven, Celestijnenlaan 200D bus 2401, 3001 Leuven (Belgium); Foley, Ryan J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Karakas, Amanda I. [Research School of Astronomy and Astrophysics, The Australian National University, Weston, ACT 2611 (Australia); Patat, F. [European Southern Observatory (ESO), Karl Schwarschild Strasse 2, D-85748, Garching bei München (Germany); Sternberg, A. [Max Planck Institute for Astrophysics, Karl Schwarzschild Strasse 1, D-85741 Garching bei München (Germany); Williams, R. E. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Gal-Yam, A. [Benoziyo Center for Astrophysics, Faculty of Physics, Weizmann Institute of Science, Rehovot 76100 (Israel); Leonard, D. C. [Department of Astronomy, San Diego State University, San Diego, CA 92182 (United States); Stritzinger, Maximilian [Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Folatelli, Gastón, E-mail: mmp@lco.cl [Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, the University of Tokyo, Kashiwa 277-8583 (Japan); and others

    2013-12-10

    High-dispersion observations of the Na I D λλ5890, 5896 and K I λλ7665, 7699 interstellar lines, and the diffuse interstellar band at 5780 Å in the spectra of 32 Type Ia supernovae are used as an independent means of probing dust extinction. We show that the dust extinction of the objects where the diffuse interstellar band at 5780 Å is detected is consistent with the visual extinction derived from the supernova colors. This strongly suggests that the dust producing the extinction is predominantly located in the interstellar medium of the host galaxies and not in circumstellar material associated with the progenitor system. One quarter of the supernovae display anomalously large Na I column densities in comparison to the amount of dust extinction derived from their colors. Remarkably, all of the cases of unusually strong Na I D absorption correspond to 'Blueshifted' profiles in the classification scheme of Sternberg et al. This coincidence suggests that outflowing circumstellar gas is responsible for at least some of the cases of anomalously large Na I column densities. Two supernovae with unusually strong Na I D absorption showed essentially normal K I column densities for the dust extinction implied by their colors, but this does not appear to be a universal characteristic. Overall, we find the most accurate predictor of individual supernova extinction to be the equivalent width of the diffuse interstellar band at 5780 Å, and provide an empirical relation for its use. Finally, we identify ways of producing significant enhancements of the Na abundance of circumstellar material in both the single-degenerate and double-degenerate scenarios for the progenitor system.

  16. 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.

  17. X-ray laser implementation by means of a strong source of high-spin metastable atoms

    International Nuclear Information System (INIS)

    Helman, J.S.; Rau, C.; Bunge, C.F.

    1983-01-01

    High-spin metastable atomic beams of high density and extremely small divergence can be produced by electron capture during grazing-angle scattering of ion beams at ferromagnetic surfaces. This can be used to generate a long-lived reservoir of Li 1s2s2p 4 P/sub 5/2//sup ts0/ with enough density of metastables so that after laser-induced transfer to Li 1s2p/sup ts2/P strong lasing at 207 A should occur. This novel technique can also be used to produce a variety of other metastables known as potential candidates for lasing at shorter wavelengths

  18. Carbon and nitrogen stable isotope ratios analysis of food sources for Chironomus acerbiphilus larvae (Diptera Chironomidae) in strongly acidic lake Katanuma

    Energy Technology Data Exchange (ETDEWEB)

    Doi, Hideyuki [Tohoku Univ., Sendai (Japan). Graduate School of Science; Kikuchi, Eisuke; Shikano, Shuichi

    2001-12-01

    The food sources for Chironomus acerbiphilus larvae (Diptera Chironomidae) were analyzed using carbon and nitrogen stable isotope ratios in Lake Katanuma. Lake Katanuma is a volcanic and strongly acidic lake (average pH 2.2). In Lake Katanuma, potential sources of diets for the chironomid larvae are limited including a benthic diatom (Pinnularia braunii), a phytoplankton (Chlamydomonas acidophila), sulfate oxidizing bacteria, and vascular plants supplied from vegetation surrounding the lake. Based on the average carbon and nitrogen isotope ratios among these potential sources and sediment, benthic diatoms were considered to be most probable food source of the chironomid larvae. {delta}{sup 13}C values of the chironomid were significantly different among seasons and habitat depths, suggesting that diet of C. acerbiphilus changed seasonally and with habitat depth. (author)

  19. Carbon and nitrogen stable isotope ratios analysis of food sources for Chironomus acerbiphilus larvae (Diptera Chironomidae) in strongly acidic lake Katanuma

    International Nuclear Information System (INIS)

    Doi, Hideyuki; Kikuchi, Eisuke; Shikano, Shuichi

    2001-01-01

    The food sources for Chironomus acerbiphilus larvae (Diptera Chironomidae) were analyzed using carbon and nitrogen stable isotope ratios in Lake Katanuma. Lake Katanuma is a volcanic and strongly acidic lake (average pH 2.2). In Lake Katanuma, potential sources of diets for the chironomid larvae are limited including a benthic diatom (Pinnularia braunii), a phytoplankton (Chlamydomonas acidophila), sulfate oxidizing bacteria, and vascular plants supplied from vegetation surrounding the lake. Based on the average carbon and nitrogen isotope ratios among these potential sources and sediment, benthic diatoms were considered to be most probable food source of the chironomid larvae. δ 13 C values of the chironomid were significantly different among seasons and habitat depths, suggesting that diet of C. acerbiphilus changed seasonally and with habitat depth. (author)

  20. Dipole response of 76Se above 4 MeV

    Science.gov (United States)

    Goddard, P. M.; Cooper, N.; Werner, V.; Rusev, G.; Stevenson, P. D.; Rios, A.; Bernards, C.; Chakraborty, A.; Crider, B. P.; Glorius, J.; Ilieva, R. S.; Kelley, J. H.; Kwan, E.; Peters, E. E.; Pietralla, N.; Raut, R.; Romig, C.; Savran, D.; Schnorrenberger, L.; Smith, M. K.; Sonnabend, K.; Tonchev, A. P.; Tornow, W.; Yates, S. W.

    2013-12-01

    The dipole response of 3476Se in the energy range from 4 to 9 MeV has been analyzed using a (γ⃗,γ') polarized photon scattering technique, performed at the High Intensity γ-Ray Source facility at Triangle Universities Nuclear Laboratory, to complement previous work performed using unpolarized photons. The results of this work offer both an enhanced sensitivity scan of the dipole response and an unambiguous determination of the parities of the observed J=1 states. The dipole response is found to be dominated by E1 excitations, and can reasonably be attributed to a pygmy dipole resonance. Evidence is presented to suggest that a significant amount of directly unobserved excitation strength is present in the region, due to unobserved branching transitions in the decays of resonantly excited states. The dipole response of the region is underestimated when considering only ground state decay branches. We investigate the electric dipole response theoretically, performing calculations in a three-dimensional (3D) Cartesian-basis time-dependent Skyrme-Hartree-Fock framework.

  1. Continuous millennial decrease of the Earth's magnetic axial dipole

    Science.gov (United States)

    Poletti, Wilbor; Biggin, Andrew J.; Trindade, Ricardo I. F.; Hartmann, Gelvam A.; Terra-Nova, Filipe

    2018-01-01

    Since the establishment of direct estimations of the Earth's magnetic field intensity in the first half of the nineteenth century, a continuous decay of the axial dipole component has been observed and variously speculated to be linked to an imminent reversal of the geomagnetic field. Furthermore, indirect estimations from anthropologically made materials and volcanic derivatives suggest that this decrease began significantly earlier than direct measurements have been available. Here, we carefully reassess the available archaeointensity dataset for the last two millennia, and show a good correspondence between direct (observatory/satellite) and indirect (archaeomagnetic) estimates of the axial dipole moment creating, in effect, a proxy to expand our analysis back in time. Our results suggest a continuous linear decay as the most parsimonious long-term description of the axial dipole variation for the last millennium. We thus suggest that a break in the symmetry of axial dipole moment advective sources occurred approximately 1100 years earlier than previously described. In addition, based on the observed dipole secular variation timescale, we speculate that the weakening of the axial dipole may end soon.

  2. A Novel Blind Source Separation Algorithm and Performance Analysis of Weak Signal against Strong Interference in Passive Radar Systems

    Directory of Open Access Journals (Sweden)

    Chengjie Li

    2016-01-01

    Full Text Available In Passive Radar System, obtaining the mixed weak object signal against the super power signal (jamming is still a challenging task. In this paper, a novel framework based on Passive Radar System is designed for weak object signal separation. Firstly, we propose an Interference Cancellation algorithm (IC-algorithm to extract the mixed weak object signals from the strong jamming. Then, an improved FastICA algorithm with K-means cluster is designed to separate each weak signal from the mixed weak object signals. At last, we discuss the performance of the proposed method and verify the novel method based on several simulations. The experimental results demonstrate the effectiveness of the proposed method.

  3. Overview of the relations earthquake source parameters and the specification of strong ground motion for design purposes

    International Nuclear Information System (INIS)

    Bernreuter, D.L.

    1977-08-01

    One of the most important steps in the seismic design process is the specification of the appropriate ground motion to be input into the design analysis. From the point-of-view of engineering design analysis, the important parameters are peak ground acceleration, spectral shape and peak spectral levels. In a few cases, ground displacement is a useful parameter. The earthquake is usually specified by giving its magnitude and either the epicentral distance or the distance of the closest point on the causitive fault to the site. Typically, the appropriate ground motion parameters are obtained using the specified magnitude and distance in equations obtained from regression analysis among the appropriate variables. Two major difficulties with such an approach are: magnitude is not the best parameter to use to define the strength of an earthquake, and little near-field data is available to establish the appropriate form for the attenuation of the ground motion with distance, source size and strength. These difficulties are important for designing a critical facility; i.e., one for which a very low risk of exceeding the design ground motion is required. Examples of such structures are nuclear power plants, schools and hospitals. for such facilities, a better understanding of the relation between the ground motion and the important earthquake source parameters could be very useful for several reasons

  4. Magnitude, direction and location of the resultant dipole moment of the pig heart.

    Science.gov (United States)

    Hodgkin, B C; Nelson, C V; Angelakos, E T

    1976-04-01

    Vectorcardiograms were obtained from 50 young domestic pigs using the Nelson lead system. Compensation for body size and shape is achieved and the resultant dipole moment magnitude reflects heart size. A strong relationship was found between heart size and maximum magnitude. Dipole moment magnitude increased as four pigs increased from five to ten weeks of age. The dipole moment during QRS is considered in light of known pig heart excitation pattern. Dipole locations during QRS, calculated by computer solution of the Gabor-Nelson equations, were in agreement with heart location and excitation data.

  5. High-field strong-focusing undulator designs for X-ray Linac Coherent Light Source (LCLS) applications

    International Nuclear Information System (INIS)

    Caspi, S.; Schlueter, R.; Tatchyn, R.

    1995-01-01

    Linac-driven X-Ray Free Electron Lasers (e.g., Linac Coherent Light Sources (LCLSs)), operating on the principle of single-pass saturation in the Self-Amplified Spontaneous Emission (SASE) regime typically require multi-GeV beam energies and undulator lengths in excess of tens of meters to attain sufficient gain in the 1 angstrom--0.1 angstrom range. In this parameter regime, the undulator structure must provide: (1) field amplitudes B 0 in excess of 1T within periods of 4cm or less, (2) peak on-axis focusing gradients on the order of 30T/m, and (3) field quality in the 0.1%--0.3% range. In this paper the authors report on designs under consideration for a 4.5--1.5 angstrom LCLS based on superconducting (SC), hybrid/PM, and pulsed-Cu technologies

  6. An empirical assessment of near-source strong ground motion for a 6.6 mb (7.5 MS) earthquake in the Eastern United States

    International Nuclear Information System (INIS)

    Campbell, Kenneth W.

    1984-06-01

    To help assess the impact of the current U.S. Geological Survey position on the seismic safety of nuclear power plants in the Eastern United States (EUS), several techniques for estimating near-source strong ground motion for a Charleston size earthquake were evaluated. The techniques for estimating the near-source strong ground motion for a 6.6 m b (7.5 M S ) in the Eastern United States which were assessed are methods based on site specific analyses, semi-theoretical scaling techniques, and intensity-based estimates. The first involves the statistical analysis of ground motion records from earthquakes and recording stations having the same general characteristics (earthquakes with magnitudes of 7.5 M S or larger, epicentral distances of 25 km or less, and sites of either soil or rock). Some recommendations for source and characterization scaling of the bias resulting primarily from an inadequate sample of near-source recordings from earthquakes of large magnitude are discussed. The second technique evaluated requires that semi-theoretical estimates of peak ground motion parameters for a 6.6 m b (7.5 M S ) earthquake be obtained from scaling relations. Each relation uses a theoretical expression between peak acceleration magnitude and distance together with available strong motion data (majority coming from California) to develop a scaling relation appropriate for the Eastern United States. None of the existing ground motion models for the EUS include the potential effects of source or site characteristics. Adjustments to account for fault mechanisms, site topography, site geology, and the size and embedment of buildings are discussed. The final approach used relations between strong ground motion parameters and Modified Mercalli Intensity in conjunction with two methods to estimate peak parameters for a 6.6 m s (7.5 M S ) earthquake. As with other techniques, adjustment of peak acceleration estimates are discussed. Each method differently approaches the problem

  7. The SCEC Broadband Platform: A Collaborative Open-Source Software Package for Strong Ground Motion Simulation and Validation

    Science.gov (United States)

    Silva, F.; Maechling, P. J.; Goulet, C. A.; Somerville, P.; Jordan, T. H.

    2014-12-01

    The Southern California Earthquake Center (SCEC) Broadband Platform is a collaborative software development project involving geoscientists, earthquake engineers, graduate students, and the SCEC Community Modeling Environment. The SCEC Broadband Platform (BBP) is open-source scientific software that can generate broadband (0-100Hz) ground motions for earthquakes, integrating complex scientific modules that implement rupture generation, low and high-frequency seismogram synthesis, non-linear site effects calculation, and visualization into a software system that supports easy on-demand computation of seismograms. The Broadband Platform operates in two primary modes: validation simulations and scenario simulations. In validation mode, the Platform runs earthquake rupture and wave propagation modeling software to calculate seismograms for a well-observed historical earthquake. Then, the BBP calculates a number of goodness of fit measurements that quantify how well the model-based broadband seismograms match the observed seismograms for a certain event. Based on these results, the Platform can be used to tune and validate different numerical modeling techniques. In scenario mode, the Broadband Platform can run simulations for hypothetical (scenario) earthquakes. In this mode, users input an earthquake description, a list of station names and locations, and a 1D velocity model for their region of interest, and the Broadband Platform software then calculates ground motions for the specified stations. Working in close collaboration with scientists and research engineers, the SCEC software development group continues to add new capabilities to the Broadband Platform and to release new versions as open-source scientific software distributions that can be compiled and run on many Linux computer systems. Our latest release includes 5 simulation methods, 7 simulation regions covering California, Japan, and Eastern North America, the ability to compare simulation results

  8. Effects of gastrointestinal tissue structure on computed dipole vectors

    Directory of Open Access Journals (Sweden)

    Pullan Andrew J

    2007-10-01

    Full Text Available Abstract Background Digestive diseases are difficult to assess without using invasive measurements. Non-invasive measurements of body surface electrical and magnetic activity resulting from underlying gastro-intestinal activity are not widely used, in large due to their difficulty in interpretation. Mathematical modelling of the underlying processes may help provide additional information. When modelling myoelectrical activity, it is common for the electrical field to be represented by equivalent dipole sources. The gastrointestinal system is comprised of alternating layers of smooth muscle (SM cells and Interstitial Cells of Cajal (ICC. In addition the small intestine has regions of high curvature as the intestine bends back upon itself. To eventually use modelling diagnostically, we must improve our understanding of the effect that intestinal structure has on dipole vector behaviour. Methods Normal intestine electrical behaviour was simulated on simple geometries using a monodomain formulation. The myoelectrical fields were then represented by their dipole vectors and an examination on the effect of structure was undertaken. The 3D intestine model was compared to a more computationally efficient 1D representation to determine the differences on the resultant dipole vectors. In addition, the conductivity values and the thickness of the different muscle layers were varied in the 3D model and the effects on the dipole vectors were investigated. Results The dipole vector orientations were largely affected by the curvature and by a transmural gradient in the electrical wavefront caused by the different properties of the SM and ICC layers. This gradient caused the dipoles to be oriented at an angle to the principal direction of electrical propagation. This angle increased when the ratio of the longitudinal and circular muscle was increased or when the the conductivity along and across the layers was increased. The 1D model was able to represent the

  9. Minimum Q Electrically Small Spherical Magnetic Dipole Antenna - Practice

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Breinbjerg, Olav

    2009-01-01

    Practical aspects of applying a magnetic core to approach the Chu lower bound for the radiation Q factor of an electrically small magnetic dipole antenna are considered. It is shown that although a magnetic core does reduce the Q factor, its effect is not as strong as predicted by Wheeler...

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. On the Effect of Dipole-Dipole Interactions on the Quantum Statistics of Surface Plasmons in Multiparticle Spaser Systems

    Science.gov (United States)

    Shesterikov, A. V.; Gubin, M. Yu.; Karpov, S. N.; Prokhorov, A. V.

    2018-04-01

    The problem of controlling the quantum dynamics of localized plasmons has been considered in the model of a four-particle spaser composed of metallic nanoparticles and semiconductor quantum dots. Conditions for the observation of stable steady-state regimes of the formation of surface plasmons in this model have been determined in the mean-field approximation. It has been shown that the presence of strong dipole-dipole interactions between metallic nanoparticles of the spaser system leads to a considerable change in the quantum statistics of plasmons generated on the nanoparticles.

  16. The influence of Indian Ocean Dipole (IOD) on biogeochemistry of ...

    Indian Academy of Sciences (India)

    Positive SST anomalies (SSTA) were found in the Arabian Sea (0.4 to 1.8 ... Keywords. Indian Ocean Dipole; biogeochemistry; carbon; chlorophyll; Arabian Sea; models. ... mainly control the strength of this source (Sarma ... of the CO2 evasion at the air–water interface (70 ..... tive SSHA due to asymmetric effect of upwelling.

  17. Electric dipole moments of the nucleon and light nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Wirzba, Andreas

    2014-08-15

    The electric dipole moments of the nucleon and light ions are discussed and strategies for disentangling the underlying sources of CP violation beyond the Kobayashi–Maskawa quark-mixing mechanism of the Standard Model are indicated. Contribution to “45 years of nuclear theory at Stony Brook: a tribute to Gerald E. Brown”.

  18. Searches for permanent electric dipole moments in Radium isotopes

    NARCIS (Netherlands)

    Willmann, L.; Jungmann, K.; Wilschut, H.W.

    2010-01-01

    Permanent electric dipole moments are uniquely sensitive to sources of T and P violation in fundamental interactions. In particular radium isotopes offer the largest intrinsic sensitivity. We want to explore the prospects for utilizing the high intense beams from HIE-ISOLDE to boost the statistical

  19. A novel inversion scheme for a magnetic dipole

    International Nuclear Information System (INIS)

    Koka, S.; Valsakumar, M.C.; Janawadkar, M.P.; Radhakrishnan, T.S.

    1997-01-01

    In a number of applications of SQUID devices such as biomagnetism, there is a need to infer the position and strength of the source(s) of the magnetic field on the basis of measurements of magnetic fields H and magnetic field gradients δH j /δx k at suitable observation point(s). It is well known that while a specification of sources uniquely determines the resulting field distribution, the inverse problem, in general, does not admit of a unique solution. However, there exist circumstances under which the source may be modeled reasonably well as a single magnetic dipole m. A novel method, which gives a unique solution to localize such a dipole source by measuring all the magnetic field components and their spatial derivatives at a single arbitrary point in space is reported

  20. 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.

  1. 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)

  2. 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.

  3. 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

  4. 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

  5. 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...

  6. Dipole location using SQUID based measurements: Application to magnetocardiography

    Science.gov (United States)

    Mariyappa, N.; Parasakthi, C.; Sengottuvel, S.; Gireesan, K.; Patel, Rajesh; Janawadkar, M. P.; Sundar, C. S.; Radhakrishnan, T. S.

    2012-07-01

    We report a method of inferring the dipole location using iterative nonlinear least square optimization based on Levenberg-Marquardt algorithm, wherein, we use different sets of pseudo-random numbers as initial parameter values. The method has been applied to (i) the simulated data representing the calculated magnetic field distribution produced by a point dipole placed at a known position, (ii) the experimental data from SQUID based measurements of the magnetic field distribution produced by a source coil carrying current, and (iii) the actual experimentally measured magnetocardiograms of human subjects using a SQUID based system.

  7. 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 ...

  8. 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.

  9. Study of top quark dipole interactions in t t \\xAF production associated with two heavy gauge bosons at the LHC

    Science.gov (United States)

    Etesami, Seyed Mohsen; Khatibi, Sara; Mohammadi Najafabadi, Mojtaba

    2018-04-01

    In this paper, we investigate the prospects of measuring the strong and weak dipole moments of the top quark at the Large Hadron Collider (LHC). Measurements of these couplings provide an excellent opportunity to probe new physics interactions as they have quite small magnitudes in the standard model. Our analyses are performed using the production cross sections of t t ¯W W and t t ¯Z Z processes in the same sign dilepton and four-lepton final states, respectively. The sensitivities to strong and weak top quark dipole interactions at the 95% confidence level for various integrated luminosity scenarios are derived and compared with other studies. To estimate the constraints, the main source of backgrounds and a realistic simulation of the detector response are considered.

  10. 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...

  11. 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

  12. 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

  13. Enhanced terahertz magnetic dipole response by subwavelength fiber

    Directory of Open Access Journals (Sweden)

    Shaghik Atakaramians

    2018-05-01

    Full Text Available 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 in the terahertz frequency range. By placing the fiber next to the hole in a metal screen, we find that the radiation power can be enhanced more than one order of magnitude. The enhancement is due to the excitation of the Mie-type resonances in the fiber. We demonstrate that such a system is equivalent to a double-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-wavelength fiber. It can also be scaled down to optical frequencies opening up promising avenues for developing integrated nanophotonic devices such as nanoantennas or lasers on fibers.

  14. IS THE TWO MICRON ALL SKY SURVEY CLUSTERING DIPOLE CONVERGENT?

    International Nuclear Information System (INIS)

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

    2011-01-01

    There is a long-standing controversy about the convergence of the dipole moment of the galaxy angular distribution (the so-called clustering dipole). Is the dipole convergent at all, and if so, what is the scale of the convergence? We study the growth of the clustering dipole of galaxies as a function of the limiting flux of the sample from the Two Micron All Sky Survey (2MASS). Contrary to some earlier claims, we find that the dipole does not converge before the completeness limit of the 2MASS Extended Source Catalog, i.e., up to 13.5 mag in the near-infrared K s band (equivalent to an effective distance of 300 Mpc h -1 ). We compare the observed growth of the dipole with the theoretically expected, conditional one (i.e., given the velocity of the Local Group relative to the cosmic microwave background), for the ΛCDM power spectrum and cosmological parameters constrained by the Wilkinson Microwave Anisotropy Probe. The observed growth turns out to be within 1σ confidence level of its theoretical counterpart once the proper observational window of the 2MASS flux-limited catalog is included. For a contrast, if the adopted window is a top hat, then the predicted dipole grows significantly faster and converges (within the errors) to its final value for a distance of about 300 Mpc h -1 . By comparing the observational windows, we show that for a given flux limit and a corresponding distance limit, the 2MASS flux-weighted window passes less large-scale signal than the top-hat one. We conclude that the growth of the 2MASS dipole for effective distances greater than 200 Mpc h -1 is only apparent. On the other hand, for a distance of 80 Mpc h -1 (mean depth of the 2MASS Redshift Survey) and the ΛCDM power spectrum, the true dipole is expected to reach only ∼80% of its final value. Eventually, since for the window function of 2MASS the predicted growth is consistent with the observed one, we can compare the two to evaluate β ≡ Ω m 0.55 /b. The result is β = 0.38

  15. 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.

  16. 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

  17. Beam Manipulation with an RF Dipole

    International Nuclear Information System (INIS)

    Bai, M.

    1999-01-01

    Coherent betatron motion adiabatically excited by an RF dipole has been successfully employed to overcome strong intrinsic spin depolarization resonances in the AGS, while a solenoid partial snake has been used to correct imperfection spin resonances. The experimental results showed that a full spin flip was obtained in passing through an intrinsic spin resonance when all the beam particles were forced to oscillate coherently at a large amplitude without diluting the beam emittance. With this method, they have successfully accelerated polarized beam up to 23.5 GeV/c. A new type of second order spin resonances was also discovered. As a non-destructive manipulation, this method can also be used for nonlinear beam dynamics studies and beam diagnosis such as measuring phase advance and betatron amplitude function

  18. Electric Dipole Theory of Chemical Synaptic Transmission

    Science.gov (United States)

    Wei, Ling Y.

    1968-01-01

    In this paper we propose that chemicals such as acetylcholine are electric dipoles which when oriented and arranged in a large array could produce an electric field strong enough to drive positive ions over the junction barrier of the post-synaptic membrane and thus initiate excitation or produce depolarization. This theory is able to explain a great number of facts such as cleft size, synaptic delay, nonregeneration, subthreshold integration, facilitation with repetition, and the calcium and magnesium effects. It also shows why and how acetylcholine could act as excitatory or inhibitory transmitters under different circumstances. Our conclusion is that the nature of synaptic transmission is essentially electrical, be it mediated by electrical or chemical transmitters. PMID:4296121

  19. 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

  20. Manipulation of positron orbits in a dipole magnetic field with fluctuating electric fields

    Science.gov (United States)

    Saitoh, H.; Horn-Stanja, J.; Nißl, S.; Stenson, E. V.; Hergenhahn, U.; Pedersen, T. Sunn; Singer, M.; Dickmann, M.; Hugenschmidt, C.; Stoneking, M. R.; Danielson, J. R.; Surko, C. M.

    2018-01-01

    We report the manipulation of positron orbits in a toroidal dipole magnetic field configuration realized with electric fields generated by segmented electrodes. When the toroidal circulation motion of positrons in the dipole field is coupled with time-varying electric fields generated by azimuthally segmented outer electrodes, positrons undergo oscillations of their radial positions. This enables quick manipulation of the spatial profiles of positrons in a dipole field trap by choosing appropriate frequency, amplitude, phase, and gating time of the electric fields. According to numerical orbit analysis, we applied these electric fields to positrons injected from the NEPOMUC slow positron facility into a prototype dipole field trap experiment with a permanent magnet. Measurements with annihilation γ-rays clearly demonstrated the efficient compression effects of positrons into the strong magnetic field region of the dipole field configuration. This positron manipulation technique can be used as one of essential tools for future experiments on the formation of electron-positron plasmas.

  1. 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.

  2. 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...

  3. 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.

  4. Simulation of Light Collection for Neutron Electrical Dipole Moment measurement

    Science.gov (United States)

    Ji, Pan; nEDM Collaboration

    2017-09-01

    nEDM (Neutron Electrical Dipole moment) measurement addresses a critical topic in particle physics and Standard Model, that is CPT violation in neutron electrical dipole moment if detected in which the Time reversal violation is connected to the matter/antimatter imparity of the universe. The neutron electric dipole moment was first measured in 1950 by Smith, Purcell, and Ramsey at the Oak Ridge Reactor - the first intense neutron source. This measurement showed that the neutron was very nearly round (to better than one part in a million). The goal of the nEDM experiment is to further improve the precision of this measurement by another factor of 100. The signal from the experiment is detected by collecting the photons generated when neutron beams were captured by liquid helium 3. The Geant4 simulation project that I participate simulates the process of light collection to improve the design for higher capture efficiency. The simulated geometry includes light source, reflector, wavelength shifting fibers, wavelength shifting TPB and acrylic as in real experiment. The UV photons exiting from Helium go through two wavelength-shifting processes in TPB and fibers to be finally captured. Oak Ridge National Laboratory Neutron Electric Dipole Moment measurement project.

  5. The RINGO2 and DIPOL optical polarization catalogue of blazars

    Science.gov (United States)

    Jermak, H.; Steele, I. A.; Lindfors, E.; Hovatta, T.; Nilsson, K.; Lamb, G. P.; Mundell, C.; Barres de Almeida, U.; Berdyugin, A.; Kadenius, V.; Reinthal, R.; Takalo, L.

    2016-11-01

    We present ˜2000 polarimetric and ˜3000 photometric observations of 15 γ-ray bright blazars over a period of 936 days (2008-10-11 to 2012-10-26) using data from the Tuorla blazar monitoring program (KVA DIPOL) and Liverpool Telescope (LT) RINGO2 polarimeters (supplemented with data from SkyCamZ (LT) and Fermi-LAT γ-ray data). In 11 out of 15 sources we identify a total of 19 electric vector position angle (EVPA) rotations and 95 flaring episodes. We group the sources into subclasses based on their broad-band spectral characteristics and compare their observed optical and γ-ray properties. We find that (1) the optical magnitude and γ-ray flux are positively correlated, (2) EVPA rotations can occur in any blazar subclass, four sources show rotations that go in one direction and immediately rotate back, (3) we see no difference in the γ-ray flaring rates in the sample; flares can occur during and outside of rotations with no preference for this behaviour, (4) the average degree of polarization (DoP), optical magnitude and γ-ray flux are lower during an EVPA rotation compared with during non-rotation and the distribution of the DoP during EVPA rotations is not drawn from the same parent sample as the distribution outside rotations, (5) the number of observed flaring events and optical polarization rotations are correlated, however we find no strong evidence for a temporal association between individual flares and rotations and (6) the maximum observed DoP increases from ˜10 per cent to ˜30 per cent to ˜40 per cent for subclasses with synchrotron peaks at high, intermediate and low frequencies, respectively.

  6. Decay properties of the Pygmy dipole resonance

    Energy Technology Data Exchange (ETDEWEB)

    Isaak, J.; Savran, D.; Silva, J. [EMMI, Darmstadt (Germany); FIAS, Frankfurt (Germany); Aumann, T.; Loeher, B. [IKP, TU Darmstadt (Germany); GSI, Darmstadt (Germany); Beck, T.; Gayer, U.; Pietralla, N.; Romig, C.; Scheit, H.; Werner, V.; Zweidinger, M. [IKP, TU Darmstadt (Germany); Cooper, N. [WNSL, Yale University, New Haven (United States); Derya, V.; Zilges, A. [IKP, Universitaet zu Koeln (Germany); Kelley, J. [Department of Physics, Duke University, TUNL (United States); Department of Physics, NCSU (United States); Scheck, M. [School of Engineering, UWS, Paisley (United Kingdom); SUPA, Glasgow (United Kingdom); Tornow, W.; Weller, H. [Department of Physics, Duke University, TUNL (United States)

    2015-07-01

    The so-called Pygmy Dipole Resonance (PDR) has been investigated in stable and in a few unstable nuclei in the past decades. So far, decay properties have been determined only in an indirect or model-dependent way. An excellent tool to extend the study of the decay pattern of the PDR is provided by the γ{sup 3}-setup at the High Intensity γ-ray Source (HIγS). The combination of the γ-γ-coincidence method and the quasi-monochromatic photon beam at HIγS allows to observe primary transitions directly with high sensitivity and to obtain information on the decay behavior of individual states as well as extracting averaged quantities in a model-independent way. Recent experimental results for nuclei in the Z=50 and N=82 mass region are presented.

  7. 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

  8. Magnetic dipole strength in 128Xe and 134Xe in the spin-flip resonance region

    Science.gov (United States)

    Massarczyk, R.; Rusev, G.; Schwengner, R.; Dönau, F.; Bhatia, C.; Gooden, M. Â. E.; Kelley, J. Â. H.; Tonchev, A. Â. P.; Tornow, W.

    2014-11-01

    The magnetic dipole strength in the energy region of the spin-flip resonance is investigated in 128Xe and 134Xe using quasimonoenergetic and linearly polarized γ -ray beams at the High-Intensity γ -Ray Source facility in Durham, North Carolina, USA. Absorption cross sections were deduced for the magnetic and electric and dipole strength distributions separately for various intervals of excitation energy, including the strength of states in the unresolved quasicontinuum. The magnetic dipole strength distributions show structures resembling a resonance in the spin-flip region around an excitation energy of 8 MeV. The electric dipole strength distributions obtained from the present experiments are in agreement with the ones deduced from an earlier experiment using broad-band bremsstrahlung instead of a quasimonoenergetic beam. The experimental magnetic and electric dipole strength distributions are compared with phenomenological approximations and with predictions of a quasiparticle random phase approximation in a deformed basis.

  9. 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.

  10. Source rupture process of the 2016 Kaikoura, New Zealand earthquake estimated from the kinematic waveform inversion of strong-motion data

    Science.gov (United States)

    Zheng, Ao; Wang, Mingfeng; Yu, Xiangwei; Zhang, Wenbo

    2018-03-01

    On 2016 November 13, an Mw 7.8 earthquake occurred in the northeast of the South Island of New Zealand near Kaikoura. The earthquake caused severe damages and great impacts on local nature and society. Referring to the tectonic environment and defined active faults, the field investigation and geodetic evidence reveal that at least 12 fault sections ruptured in the earthquake, and the focal mechanism is one of the most complicated in historical earthquakes. On account of the complexity of the source rupture, we propose a multisegment fault model based on the distribution of surface ruptures and active tectonics. We derive the source rupture process of the earthquake using the kinematic waveform inversion method with the multisegment fault model from strong-motion data of 21 stations (0.05-0.35 Hz). The inversion result suggests the rupture initiates in the epicentral area near the Humps fault, and then propagates northeastward along several faults, until the offshore Needles fault. The Mw 7.8 event is a mixture of right-lateral strike and reverse slip, and the maximum slip is approximately 19 m. The synthetic waveforms reproduce the characteristics of the observed ones well. In addition, we synthesize the coseismic offsets distribution of the ruptured region from the slips of upper subfaults in the fault model, which is roughly consistent with the surface breaks observed in the field survey.

  11. The peculiar acceleration of the Local Group as deduced from the optical and IRAS flux dipoles

    International Nuclear Information System (INIS)

    Lahav, O.; Lynden-Bell, D.

    1988-01-01

    The relation between the peculiar acceleration of the Local Group and the surface brightness dipole moments of all-sky optical and IRAS samples is studied. Our revised optical dipole lies within 7 0 of the direction of the Local Group's motion through the Microwave Background Radiation (MBR). The directions of the optical, IRAS and MBR dipoles are all consistent with each other. To analyse the optical dipole we have calculated diameter functions for the UGC and ESO galaxy catalogues from redshift surveys. Most of the optical dipole arises from the Centaurus-Virgo direction and from the 'Local Void' on the opposite side of the sky. The sources of the IRAS dipole are more evenly distributed around the sky. A simple 'shell model', fitted to the variation of the dipoles as a function of flux, suggests that the dipoles arise from galaxies whose recession velocities are smaller than 4000 kms -1 . We find a high Ω 0 value for the IRAS sample and a low one for the optical sample. These results may be reconciled if the optical galaxy distribution is more biased relative to the matter distribution than the IRAS galaxy distribution. (author)

  12. Electric Dipole Echoes and Noise-Induced Coherence

    International Nuclear Information System (INIS)

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

    2007-01-01

    The generation of echoes in the electric dipole moment of a Rydberg wavepacket precessing in an external electric field by reversal of the field is described. When the wavepacket experiences reversible dephasing, large echoes are observed pointing to strong refocusing of the wavepacket. The presence of irreversible dephasing leads to a reduction in the size of the echoes. The effect of irreversible dynamics on echoes is investigated using artificially synthesized noise. Methods to determine the decoherence rate are discussed

  13. Electric dipole moments of nanosolvated acid molecules in water clusters.

    Science.gov (United States)

    Guggemos, Nicholas; Slavíček, Petr; Kresin, Vitaly V

    2015-01-30

    The electric dipole moments of (H2O)nDCl (n=3-9) clusters have been measured by the beam-deflection method. Reflecting the (dynamical) charge distribution within the system, the dipole moment contributes information about the microscopic structure of nanoscale solvation. The addition of a DCl molecule to a water cluster results in a strongly enhanced susceptibility. There is evidence for a noticeable rise in the dipole moment occurring at n≈5-6. This size is consistent with predictions for the onset of ionic dissociation. Additionally, a molecular-dynamics model suggests that even with a nominally bound impurity an enhanced dipole moment can arise due to the thermal and zero-point motion of the proton and the water molecules. The experimental measurements and the calculations draw attention to the importance of fluctuations in defining the polarity of water-based nanoclusters and generally to the essential role played by motional effects in determining the response of fluxional nanoscale systems under realistic conditions.

  14. Dipole-Assisted Self-Assembly of Light-Emitting p-nP Needles on Mica

    DEFF Research Database (Denmark)

    Balzer, Frank; Rubahn, Horst-Günter

    2001-01-01

    molecules oriented along the direction of microscopic dipoles on the mica surface. They have submicrometer cross-sectional dimensions and lengths as large as millimeters. Moreover, due to the strong dipole confinement of individual molecules, the needles form large domains with parallel oriented entities....... A pronounced optical dichroism agrees with the findings from LEED....

  15. First Measurement of the Atomic Electric Dipole Moment of (225)Ra.

    Science.gov (United States)

    Parker, R H; Dietrich, M R; Kalita, M R; Lemke, N D; Bailey, K G; Bishof, M; Greene, J P; Holt, R J; Korsch, W; Lu, Z-T; Mueller, P; O'Connor, T P; Singh, J T

    2015-06-12

    The radioactive radium-225 ((225)Ra) atom is a favorable case to search for a permanent electric dipole moment. Because of its strong nuclear octupole deformation and large atomic mass, (225)Ra is particularly sensitive to interactions in the nuclear medium that violate both time-reversal symmetry and parity. We have developed a cold-atom technique to study the spin precession of (225)Ra atoms held in an optical dipole trap, and demonstrated the principle of this method by completing the first measurement of its atomic electric dipole moment, reaching an upper limit of |d((225)Ra)|<5.0×10(-22)  e cm (95% confidence).

  16. 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

  17. 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).

  18. 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...

  19. The radiofrequency magnetic dipole discharge

    Energy Technology Data Exchange (ETDEWEB)

    Martines, E., E-mail: emilio.martines@igi.cnr.it; Zuin, M.; Cavazzana, R.; Fassina, A.; Spolaore, M. [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); Marcante, M. [Dipartimento di Fisica, Università di Trento, via Sommarive 14, 38123 Povo, TN (Italy); TIFPA, Trento Institute for Fundamental Physics and Applications INFN, 38123 Trento (Italy)

    2016-05-15

    This paper describes a novel and simple concept of plasma source, which is able to produce a radiofrequency magnetized discharge with minimal power requirements. The source is based on the magnetron concept and uses a permanent magnet as an active electrode. The dipolar field produced by the magnet confines the electrons, which cause further ionization, thus producing a toroidally shaped plasma in the equatorial region around the electrode. A plasma can be ignited with such scheme with power levels as low as 5 W. Paschen curves have been built for four different working gases, showing that in Helium or Neon, plasma breakdown is easily obtained also at atmospheric pressure. The plasma properties have been measured using a balanced Langmuir probe, showing that the electron temperature is around 3–4 eV and higher in the cathode proximity. Plasma densities of the order of 10{sup 16 }m{sup −3} have been obtained, with a good positive scaling with applied power. Overall, the electron pressure appears to be strongly correlated with the magnetic field magnitude in the measurement point.

  20. The radiofrequency magnetic dipole discharge

    Science.gov (United States)

    Martines, E.; Zuin, M.; Marcante, M.; Cavazzana, R.; Fassina, A.; Spolaore, M.

    2016-05-01

    This paper describes a novel and simple concept of plasma source, which is able to produce a radiofrequency magnetized discharge with minimal power requirements. The source is based on the magnetron concept and uses a permanent magnet as an active electrode. The dipolar field produced by the magnet confines the electrons, which cause further ionization, thus producing a toroidally shaped plasma in the equatorial region around the electrode. A plasma can be ignited with such scheme with power levels as low as 5 W. Paschen curves have been built for four different working gases, showing that in Helium or Neon, plasma breakdown is easily obtained also at atmospheric pressure. The plasma properties have been measured using a balanced Langmuir probe, showing that the electron temperature is around 3-4 eV and higher in the cathode proximity. Plasma densities of the order of 1016 m-3 have been obtained, with a good positive scaling with applied power. Overall, the electron pressure appears to be strongly correlated with the magnetic field magnitude in the measurement point.

  1. Avoiding bias effects in NMR experiments for heteronuclear dipole-dipole coupling determinations: principles and application to organic semiconductor materials.

    Science.gov (United States)

    Kurz, Ricardo; Cobo, Marcio Fernando; de Azevedo, Eduardo Ribeiro; Sommer, Michael; Wicklein, André; Thelakkat, Mukundan; Hempel, Günter; Saalwächter, Kay

    2013-09-16

    Carbon-proton dipole-dipole couplings between bonded atoms represent a popular probe of molecular dynamics in soft materials or biomolecules. Their site-resolved determination, for example, by using the popular DIPSHIFT experiment, can be challenged by spectral overlap with nonbonded carbon atoms. The problem can be solved by using very short cross-polarization (CP) contact times, however, the measured modulation curves then deviate strongly from the theoretically predicted shape, which is caused by the dependence of the CP efficiency on the orientation of the CH vector, leading to an anisotropic magnetization distribution even for isotropic samples. Herein, we present a detailed demonstration and explanation of this problem, as well as providing a solution. We combine DIPSHIFT experiments with the rotor-directed exchange of orientations (RODEO) method, and modifications of it, to redistribute the magnetization and obtain undistorted modulation curves. Our strategy is general in that it can also be applied to other types of experiments for heteronuclear dipole-dipole coupling determinations that rely on dipolar polarization transfer. It is demonstrated with perylene-bisimide-based organic semiconductor materials, as an example, in which measurements of dynamic order parameters reveal correlations of the molecular dynamics with the phase structure and functional properties. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. 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.

  3. 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

  4. 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

  5. Electric dipole moments of charged leptons with sterile fermions

    International Nuclear Information System (INIS)

    Abada, Asmaa; Toma, Takashi

    2016-01-01

    We address the impact of sterile fermions on charged lepton electric dipole moments. Any experimental signal of these observables calls for scenarios of physics beyond the Standard Model providing new sources of CP violation. In this work, we consider a minimal extension of the Standard Model via the addition of sterile fermions which mix with active neutrinos and we derive the corresponding analytical expressions for the electric dipole moments of charged leptons at two-loop order. Our study reveals that, in order to have a non-vanishing contribution in this framework, the minimal extension necessitates the addition of at least 2 sterile fermion states to the Standard Model field content. Our conclusion is that sterile neutrinos can give significant contributions to the charged lepton electric dipole moments, some of them lying within present and future experimental sensitivity if the masses of the non-degenerate sterile states are both above the electroweak scale. The Majorana nature of neutrinos is also important in order to allow for significative contributions to the charged lepton electric dipole moments. In our analysis we impose all available experimental and observational constraints on sterile neutrinos and we further discuss the prospect of probing this scenario at low and high energy experiments.

  6. Electric dipole moments of charged leptons with sterile fermions

    Energy Technology Data Exchange (ETDEWEB)

    Abada, Asmaa; Toma, Takashi [Laboratoire de Physique Théorique, CNRS, University Paris-Sud, Université Paris-Saclay, 91405 Orsay (France)

    2016-02-26

    We address the impact of sterile fermions on charged lepton electric dipole moments. Any experimental signal of these observables calls for scenarios of physics beyond the Standard Model providing new sources of CP violation. In this work, we consider a minimal extension of the Standard Model via the addition of sterile fermions which mix with active neutrinos and we derive the corresponding analytical expressions for the electric dipole moments of charged leptons at two-loop order. Our study reveals that, in order to have a non-vanishing contribution in this framework, the minimal extension necessitates the addition of at least 2 sterile fermion states to the Standard Model field content. Our conclusion is that sterile neutrinos can give significant contributions to the charged lepton electric dipole moments, some of them lying within present and future experimental sensitivity if the masses of the non-degenerate sterile states are both above the electroweak scale. The Majorana nature of neutrinos is also important in order to allow for significative contributions to the charged lepton electric dipole moments. In our analysis we impose all available experimental and observational constraints on sterile neutrinos and we further discuss the prospect of probing this scenario at low and high energy experiments.

  7. 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

  8. 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

  9. 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.

  10. 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)

  11. 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....

  12. Dissipation-induced dipole blockade and antiblockade in driven Rydberg systems

    Science.gov (United States)

    Young, Jeremy T.; Boulier, Thomas; Magnan, Eric; Goldschmidt, Elizabeth A.; Wilson, Ryan M.; Rolston, Steven L.; Porto, James V.; Gorshkov, Alexey V.

    2018-02-01

    We study theoretically and experimentally the competing blockade and antiblockade effects induced by spontaneously generated contaminant Rydberg atoms in driven Rydberg systems. These contaminant atoms provide a source of strong dipole-dipole interactions and play a crucial role in the system's behavior. We study this problem theoretically using two different approaches. The first is a cumulant expansion approximation, in which we ignore third-order and higher connected correlations. Using this approach for the case of resonant drive, a many-body blockade radius picture arises, and we find qualitative agreement with previous experimental results. We further predict that as the atomic density is increased, the Rydberg population's dependence on Rabi frequency will transition from quadratic to linear dependence at lower Rabi frequencies. We study this behavior experimentally by observing this crossover at two different atomic densities. We confirm that the larger density system has a smaller crossover Rabi frequency than the smaller density system. The second theoretical approach is a set of phenomenological inhomogeneous rate equations. We compare the results of our rate-equation model to the experimental observations [E. A. Goldschmidt et al., Phys. Rev. Lett. 116, 113001 (2016), 10.1103/PhysRevLett.116.113001] and find that these rate equations provide quantitatively good scaling behavior of the steady-state Rydberg population for both resonant and off-resonant drives.

  13. A Mole for Warm Magnetic and Optical Measurements of LHC Dipoles

    CERN Document Server

    Bottura, L; Deferne, G; Glöckner, C; Jansen, H; Köster, A; Legrand, P; Rijllart, A; Sievers, P

    2000-01-01

    A new rotating coil probe (a mole) has been developed for the simultaneous measurement of the magnetic field and magnetic axis of warm superconducting LHC dipoles and associated corrector windings. The mole houses a radial rotating coil and travels inside the magnet aperture by means of an externally driven two-way traction belt. The coil is rotated by an on-board piezo motor, being tested in view of future devices for cold measurements as the only type of motor compatible with strong magnetic fields. A virtual light spot is generated in the coil center by a LED source. The position of this light spot is measured from the outside by a system including a telescope, a CCD camera and a DSP. Jigs on reference granite tables are used to transfer the optical measurements to the magnet fiducials. We describe here the main characteristics and performance of the mole

  14. 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.

  15. 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...

  16. 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.

  17. Janus and Huygens Dipoles: Near-Field Directionality Beyond Spin-Momentum Locking

    Science.gov (United States)

    Picardi, Michela F.; Zayats, Anatoly V.; Rodríguez-Fortuño, Francisco J.

    2018-03-01

    Unidirectional scattering from circularly polarized dipoles has been demonstrated in near-field optics, where the quantum spin-Hall effect of light translates into spin-momentum locking. By considering the whole electromagnetic field, instead of its spin component alone, near-field directionality can be achieved beyond spin-momentum locking. This unveils the existence of the Janus dipole, with side-dependent topologically protected coupling to waveguides, and reveals the near-field directionality of Huygens dipoles, generalizing Kerker's condition. Circular dipoles, together with Huygens and Janus sources, form the complete set of all possible directional dipolar sources in the far- and near-field. This allows the designing of directional emission, scattering, and waveguiding, fundamental for quantum optical technology, integrated nanophotonics, and new metasurface designs.

  18. Many particle magnetic dipole-dipole and hydrodynamic interactions in magnetizable stent assisted magnetic drug targeting

    International Nuclear Information System (INIS)

    Cregg, P.J.; Murphy, Kieran; Mardinoglu, Adil; Prina-Mello, Adriele

    2010-01-01

    The implant assisted magnetic targeted drug delivery system of Aviles, Ebner and Ritter is considered both experimentally (in vitro) and theoretically. The results of a 2D mathematical model are compared with 3D experimental results for a magnetizable wire stent. In this experiment a ferromagnetic, coiled wire stent is implanted to aid collection of particles which consist of single domain magnetic nanoparticles (radius ∼10nm). In order to model the agglomeration of particles known to occur in this system, the magnetic dipole-dipole and hydrodynamic interactions for multiple particles are included. Simulations based on this mathematical model were performed using open source C++ code. Different initial positions are considered and the system performance is assessed in terms of collection efficiency. The results of this model show closer agreement with the measured in vitro experimental results and with the literature. The implications in nanotechnology and nanomedicine are based on the prediction of the particle efficiency, in conjunction with the magnetizable stent, for targeted drug delivery.

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. 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

  4. 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)

  5. 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.)

  6. Isospin properties of electric dipole excitations in 48Ca

    Science.gov (United States)

    Derya, V.; Savran, D.; Endres, J.; Harakeh, M. N.; Hergert, H.; Kelley, J. H.; Papakonstantinou, P.; Pietralla, N.; Ponomarev, V. Yu.; Roth, R.; Rusev, G.; Tonchev, A. P.; Tornow, W.; Wörtche, H. J.; Zilges, A.

    2014-03-01

    Two different experimental approaches were combined to study the electric dipole strength in the doubly-magic nucleus 48Ca below the neutron threshold. Real-photon scattering experiments using bremsstrahlung up to 9.9 MeV and nearly mono-energetic linearly polarized photons with energies between 6.6 and 9.51 MeV provided strength distribution and parities, and an (α,α‧γ) experiment at Eα=136 MeV gave cross sections for an isoscalar probe. The unexpected difference observed in the dipole response is compared to calculations using the first-order random-phase approximation and points to an energy-dependent isospin character. A strong isoscalar state at 7.6 MeV was identified for the first time supporting a recent theoretical prediction.

  7. Superconducting dipole magnet for the CBM experiment at FAIR

    Directory of Open Access Journals (Sweden)

    Kurilkin P.

    2017-01-01

    Full Text Available The scientific goal of the CBM (Compressed Baryonic Matter experiment at FAIR (Darmstadt is to explore the phase diagram of strongly interacting matter at highest baryon densities. The physics program of the CBM experiment is complimentary to the programs to be realized at MPD and BMN facilities at NICA and will start with beam derived by the SIS100 synchrotron. The 5.15 MJ superconducting dipole magnet will be used in the silicon tracking system of the CBM detector. The magnet will provide a magnetic field integral of 1 Tm which is required to obtain a momentum resolution of 1% for the track reconstruction. The results of the development of dipole magnet of the CBM experiment are presented.

  8. Static dipole polarizabilities of Scn (n ≤ 15) clusters

    International Nuclear Information System (INIS)

    Xi-Bo, Li; Jiang-Shan, Luo; Wei-Dong, Wu; Yong-Jian, Tang; Hong-Yan, Wang; Yun-Dong, Guo

    2009-01-01

    The static dipole polarizabilities of scandium clusters with up to 15 atoms are determined by using the numerically finite field method in the framework of density functional theory. The electronic effects on the polarizabilities are investigated for the scandium clusters. We examine a large highest occupied molecular orbital — the lowest occupied molecular orbital (HOMO–LUMO) gap of a scandium cluster usually corresponds to a large dipole moment. The static polarizability per atom decreases slowly and exhibits local minimum with increasing cluster size. The polarizability anisotropy and the ratio of mean static polarizability to the HOMO–LUMO gap can also reflect the cluster stability. The polarizability of the scandium cluster is partially related to the HOMO–LUMO gap and is also dependent on geometrical characteristics. A strong correlation between the polarizability and ionization energy is observed. (atomic and molecular physics)

  9. Final state dipole showers and the DGLAP equation

    International Nuclear Information System (INIS)

    Nagy, Zoltan; Soper, Davison E.

    2009-01-01

    We study a parton shower description, based on a dipole picture, of the final state in electron-positron annihilation. In such a shower, the distribution function describing the inclusive probability to find a quark with a given energy depends on the shower evolution time. Starting from the exclusive evolution equation for the shower, we derive an equation for the evolution of the inclusive quark energy distribution in the limit of strong ordering in shower evolution time of the successive parton splittings. We find that, as expected, this is the DGLAP equation. This paper is a response to a recent paper of Dokshitzer and Marchesini that raised troubling issues about whether a dipole based shower could give the DGLAP equation for the quark energy distribution.

  10. A design proposal for high field dipole magnet

    International Nuclear Information System (INIS)

    Hirabayashi, H.; Kobayashi, M.; Shintomi, T.; Tsuchiya, K.; Wake, M.

    1981-06-01

    A design of the high field dipole magnet which is going to be constructed in the KEK-Fermilab collaboration program is proposed. The central field of the magnet is meant to achieve 10 T by the use of ternary alloy conductor in the 1.8 K superfluid environment under atmospheric pressure. Since the electro-magnetic force in such a high field region is strong enough to give a fatal problem, a careful calculation is necessary for the magnet design. The program POISSON and LINDA were used for the magnetic field calculation. The computer code ISAS which is originated from NASTRAN developed at NASA was applied to calculate the stress and the deformation. A horizontal cryostat desigh for the operation of the 10 T dipole magnet is also proposed. (author)

  11. Open midplane designs based on sector coils in superconducting dipoles

    CERN Document Server

    Bruer, J

    2009-01-01

    This paper presents a study of the effects of opening up the midplane in conventional sector coil dipoles, also known as cosè-designs. The open midplane design is a candidate for the higher luminosity upgrade for the LHC, and also for the future beta beam project at CERN, which has the heat deposition mainly concentrated in the midplane of the dipoles. By opening up the midplane, the major part of the spray particles can be avoided, allowing the use of strong superconductive magnets. The aim of this study is to maintain good field quality after a gap in the midplane has been inserted. Short sample field and the electromagnetic force distribution will also be presented for some solutions.

  12. Isospin properties of electric dipole excitations in {sup 48}Ca

    Energy Technology Data Exchange (ETDEWEB)

    Derya, V., E-mail: derya@ikp.uni-koeln.de [Institut für Kernphysik, Universität zu Köln, 50937 Köln (Germany); Savran, D. [ExtreMe Matter Institute EMMI and Research Division, GSI, 64291 Darmstadt (Germany); Frankfurt Institute for Advanced Studies FIAS, 60438 Frankfurt am Main (Germany); Endres, J. [Institut für Kernphysik, Universität zu Köln, 50937 Köln (Germany); Harakeh, M.N. [Kernfysisch Versneller Instituut, University of Groningen, 9747 AA Groningen (Netherlands); GANIL, CEA/DSM-CNRS/IN2P3, 14076 Caen (France); Hergert, H. [Department of Physics, Ohio State University, Columbus, OH 43210 (United States); Kelley, J.H. [Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States); Papakonstantinou, P. [Rare Isotope Science Project, Institute for Basic Science, Daejeon 305-811 (Korea, Republic of); Pietralla, N.; Ponomarev, V.Yu.; Roth, R. [Institut für Kernphysik, TU Darmstadt, 64289 Darmstadt (Germany); Rusev, G.; Tonchev, A.P.; Tornow, W. [Department of Physics, Duke University, Durham, NC 27708 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); Wörtche, H.J. [Kernfysisch Versneller Instituut, University of Groningen, 9747 AA Groningen (Netherlands); Zilges, A. [Institut für Kernphysik, Universität zu Köln, 50937 Köln (Germany)

    2014-03-07

    Two different experimental approaches were combined to study the electric dipole strength in the doubly-magic nucleus {sup 48}Ca below the neutron threshold. Real-photon scattering experiments using bremsstrahlung up to 9.9 MeV and nearly mono-energetic linearly polarized photons with energies between 6.6 and 9.51 MeV provided strength distribution and parities, and an (α,α{sup ′}γ) experiment at E{sub α}=136MeV gave cross sections for an isoscalar probe. The unexpected difference observed in the dipole response is compared to calculations using the first-order random-phase approximation and points to an energy-dependent isospin character. A strong isoscalar state at 7.6 MeV was identified for the first time supporting a recent theoretical prediction.

  13. Experimental constraint on quark electric dipole moments

    Science.gov (United States)

    Liu, Tianbo; Zhao, Zhiwen; Gao, Haiyan

    2018-04-01

    The electric dipole moments (EDMs) of nucleons are sensitive probes of additional C P violation sources beyond the standard model to account for the baryon number asymmetry of the universe. As a fundamental quantity of the nucleon structure, tensor charge is also a bridge that relates nucleon EDMs to quark EDMs. With a combination of nucleon EDM measurements and tensor charge extractions, we investigate the experimental constraint on quark EDMs, and its sensitivity to C P violation sources from new physics beyond the electroweak scale. We obtain the current limits on quark EDMs as 1.27 ×10-24 e .cm for the up quark and 1.17 ×10-24 e .cm for the down quark at the scale of 4 GeV2 . We also study the impact of future nucleon EDM and tensor charge measurements, and show that upcoming new experiments will improve the constraint on quark EDMs by about 3 orders of magnitude leading to a much more sensitive probe of new physics models.

  14. 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!

  15. 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.

  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. 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. Alberta Stroke Program Early CT Score applied to CT angiography source images is a strong predictor of futile recanalization in acute ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Kawiorski, Michal M.; Alonso de Lecinana, Maria [Hospital Universitario La Paz, IdiPAZ, Universidad Autonoma de Madrid, Madrid (Spain); Hospital Universitario Ramon y Cajal, IRYCIS, Universidad de Alcala de Henares, Madrid (Spain); Martinez-Sanchez, Patricia; Fuentes, Blanca; Sanz-Cuesta, Borja E.; Marin, Begona; Ruiz-Ares, Gerardo; Diez-Tejedor, Exuperio [Hospital Universitario La Paz, IdiPAZ, Universidad Autonoma de Madrid, Madrid (Spain); Garcia-Pastor, Andres; Diaz-Otero, Fernando [Hospital Universitario Gregorio Maranon, IiSGM, Universidad Complutense de Madrid, Madrid (Spain); Calleja, Patricia [Hospital Universitario 12 de Octubre, Universidad Autonoma de Madrid, Madrid (Spain); Lourido, Daniel; Vicente, Agustina; Fandino, Eduardo [Hospital Universitario Ramon y Cajal, IRYCIS, Universidad de Alcala de Henares, Madrid (Spain); Sierra-Hidalgo, Fernando [Hospital Universitario 12 de Octubre, Universidad Autonoma de Madrid, Madrid (Spain); Hospital Universitario Infanta Leonor, Universidad Complutense de Madrid, Madrid (Spain)

    2016-05-15

    Reliable predictors of poor clinical outcome despite successful revascularization might help select patients with acute ischemic stroke for thrombectomy. We sought to determine whether baseline Alberta Stroke Program Early CT Score (ASPECTS) applied to CT angiography source images (CTA-SI) is useful in predicting futile recanalization. Data are from the FUN-TPA study registry (ClinicalTrials.gov; NCT02164357) including patients with acute ischemic stroke due to proximal arterial occlusion in anterior circulation, undergoing reperfusion therapies. Baseline non-contrast CT and CTA-SI-ASPECTS, time-lapse to image acquisition, occurrence, and timing of recanalization were recorded. Outcome measures were NIHSS at 24 h, symptomatic intracranial hemorrhage, modified Rankin scale score, and mortality at 90 days. Futile recanalization was defined when successful recanalization was associated with poor functional outcome (death or disability). Included were 110 patients, baseline NIHSS 17 (IQR 12; 20), treated with intravenous thrombolysis (IVT; 45 %), primary mechanical thrombectomy (MT; 16 %), or combined IVT + MT (39 %). Recanalization rate was 71 %, median delay of 287 min (225; 357). Recanalization was futile in 28 % of cases. In an adjusted model, baseline CTA-SI-ASPECTS was inversely related to the odds of futile recanalization (OR 0.5; 95 % CI 0.3-0.7), whereas NCCT-ASPECTS was not (OR 0.8; 95 % CI 0.5-1.2). A score ≤5 in CTA-SI-ASPECTS was the best cut-off to predict futile recanalization (sensitivity 35 %; specificity 97 %; positive predictive value 86 %; negative predictive value 77 %). CTA-SI-ASPECTS strongly predicts futile recanalization and could be a valuable tool for treatment decisions regarding the indication of revascularization therapies. (orig.)

  19. Alberta Stroke Program Early CT Score applied to CT angiography source images is a strong predictor of futile recanalization in acute ischemic stroke

    International Nuclear Information System (INIS)

    Kawiorski, Michal M.; Alonso de Lecinana, Maria; Martinez-Sanchez, Patricia; Fuentes, Blanca; Sanz-Cuesta, Borja E.; Marin, Begona; Ruiz-Ares, Gerardo; Diez-Tejedor, Exuperio; Garcia-Pastor, Andres; Diaz-Otero, Fernando; Calleja, Patricia; Lourido, Daniel; Vicente, Agustina; Fandino, Eduardo; Sierra-Hidalgo, Fernando

    2016-01-01

    Reliable predictors of poor clinical outcome despite successful revascularization might help select patients with acute ischemic stroke for thrombectomy. We sought to determine whether baseline Alberta Stroke Program Early CT Score (ASPECTS) applied to CT angiography source images (CTA-SI) is useful in predicting futile recanalization. Data are from the FUN-TPA study registry (ClinicalTrials.gov; NCT02164357) including patients with acute ischemic stroke due to proximal arterial occlusion in anterior circulation, undergoing reperfusion therapies. Baseline non-contrast CT and CTA-SI-ASPECTS, time-lapse to image acquisition, occurrence, and timing of recanalization were recorded. Outcome measures were NIHSS at 24 h, symptomatic intracranial hemorrhage, modified Rankin scale score, and mortality at 90 days. Futile recanalization was defined when successful recanalization was associated with poor functional outcome (death or disability). Included were 110 patients, baseline NIHSS 17 (IQR 12; 20), treated with intravenous thrombolysis (IVT; 45 %), primary mechanical thrombectomy (MT; 16 %), or combined IVT + MT (39 %). Recanalization rate was 71 %, median delay of 287 min (225; 357). Recanalization was futile in 28 % of cases. In an adjusted model, baseline CTA-SI-ASPECTS was inversely related to the odds of futile recanalization (OR 0.5; 95 % CI 0.3-0.7), whereas NCCT-ASPECTS was not (OR 0.8; 95 % CI 0.5-1.2). A score ≤5 in CTA-SI-ASPECTS was the best cut-off to predict futile recanalization (sensitivity 35 %; specificity 97 %; positive predictive value 86 %; negative predictive value 77 %). CTA-SI-ASPECTS strongly predicts futile recanalization and could be a valuable tool for treatment decisions regarding the indication of revascularization therapies. (orig.)

  20. <strong>Mini-project>

    DEFF Research Database (Denmark)

    Katajainen, Jyrki

    2008-01-01

    In this project the goal is to develop the safe * family of containers for the CPH STL. The containers to be developed should be safer and more reliable than any of the existing implementations. A special focus should be put on strong exception safety since none of the existing prototypes available...

  1. Understanding Rossby wave trains forced by the Indian Ocean Dipole

    Science.gov (United States)

    McIntosh, Peter C.; Hendon, Harry H.

    2018-04-01

    Convective variations over the tropical Indian Ocean associated with ENSO and the Indian Ocean Dipole force a Rossby wave train that appears to emanate poleward and eastward to the south of Australia and which causes climate variations across southern Australia and more generally throughout the Southern Hemisphere extratropics. However, during austral winter, the subtropical jet that extends from the eastern Indian Ocean into the western Pacific at Australian latitudes should effectively prohibit continuous propagation of a stationary Rossby wave from the tropics into the extratropics because the meridional gradient of mean absolute vorticity goes to zero on its poleward flank. The observed wave train indeed exhibits strong convergence of wave activity flux upon encountering this region of vanishing vorticity gradient and with some indication of reflection back into the tropics, indicating the continuous propagation of the stationary Rossby wave train from low to high latitudes is inhibited across the south of Australia. However, another Rossby wave train appears to emanate upstream of Australia on the poleward side of the subtropical jet and propagates eastward along the waveguide of the eddy-driven (sub-polar) jet into the Pacific sector of the Southern Ocean. This combination of evanescent wave train from the tropics and eastward propagating wave train emanating from higher latitudes upstream of Australia gives the appearance of a continuous Rossby wave train propagating from the tropical Indian Ocean into higher southern latitudes. The extratropical Rossby wave source on the poleward side of the subtropical jet stems from induced changes in transient eddy activity in the main storm track of the Southern Hemisphere. During austral spring, when the subtropical jet weakens, the Rossby wave train emanating from Indian Ocean convection is explained more traditionally by direct dispersion from divergence forcing at low latitudes.

  2. Electron and muon electric dipoles in supersymmetric scenarios

    CERN Document Server

    Romanino, Andrea; Romanino, Andrea; Strumia, Alessandro

    2002-01-01

    We study if a sizeable muon electric dipole can arise in supersymmetric frameworks able to account for the tight experimental bounds on sfermion masses, like an appropriate flavor symmetry, or like a flavor-blind mechanism of SUSY breaking (in presence of radiative corrections charchteristic of GUT models, or due to Yukawa couplings of neutrinos in see-saw models). In some cases it is possible to evade the naive scaling d_mu/d_e = m_mu/m_e and obtain a d_mu as large as 10^{-22--23} e cm. In most cases d_mu is around 10^{-24--25} e cm and (d_mu/d_e)/(m_mu/m_e) is only slightly different from one: this ratio contains interesting informations on the source of the dipoles and on the texture of the lepton Yukawa matrix. We also update GUT predictions for mu --> e gamma and related processes.

  3. Strong interactions

    International Nuclear Information System (INIS)

    Froissart, Marcel

    1976-01-01

    Strong interactions are introduced by their more obvious aspect: nuclear forces. In hadron family, the nucleon octet, OMEGA - decuplet, and quark triply are successively considered. Pion wave having been put at the origin of nuclear forces, low energy phenomena are described, the force being explained as an exchange of structure corresponding to a Regge trajectory in a variable rotating state instead of the exchange of a well defined particle. At high energies the concepts of pomeron, parton and stratons are introduced, pionization and fragmentation are briefly differentiated [fr

  4. Decay pattern of the Pygmy Dipole Resonance in 130Te

    Science.gov (United States)

    Isaak, J.; Beller, J.; Fiori, E.; Krtička, M.; Löher, B.; Pietralla, N.; Romig, C.; Rusev, G.; Savran, D.; Scheck, M.; Silva, J.; Sonnabend, K.; Tonchev, A.; Tornow, W.; Weller, H.; Zweidinger, M.

    2014-03-01

    The electric dipole strength distribution in 130Te has been investigated using the method of Nuclear Resonance Fluorescence. The experiments were performed at the Darmstadt High Intensity Photon Setup using bremsstrahlung as photon source and at the High Intensity overrightarrow γ -Ray Source, where quasi-monochromatic and polarized photon beams are provided. Average decay properties of 130Te below the neutron separation energy are determined. Comparing the experimental data to the predictions of the statistical model indicate, that nuclear structure effects play an important role even at sufficiently high excitation energies. Preliminary results will be presented.

  5. Decay pattern of the Pygmy Dipole Resonance in 130Te

    Directory of Open Access Journals (Sweden)

    Isaak J.

    2014-03-01

    Full Text Available The electric dipole strength distribution in 130Te has been investigated using the method of Nuclear Resonance Fluorescence. The experiments were performed at the Darmstadt High Intensity Photon Setup using bremsstrahlung as photon source and at the High Intensity γ→$\\overrightarrow \\gamma $-Ray Source, where quasi-monochromatic and polarized photon beams are provided. Average decay properties of 130Te below the neutron separation energy are determined. Comparing the experimental data to the predictions of the statistical model indicate, that nuclear structure effects play an important role even at sufficiently high excitation energies. Preliminary results will be presented.

  6. Vacuum fluctuations and radiation reaction contributions to the resonance dipole-dipole interaction between two atoms near a reflecting boundary

    Science.gov (United States)

    Zhou, Wenting; Rizzuto, Lucia; Passante, Roberto

    2018-04-01

    We investigate the resonance dipole-dipole interaction energy between two identical atoms, one in the ground state and the other in the excited state, interacting with the electromagnetic field in the presence of a perfectly reflecting plane boundary. The atoms are prepared in a correlated (symmetric or antisymmetric) Bell-type state. Following a procedure due to Dalibard et al. [J. Dalibard et al., J. Phys. (Paris) 43, 1617 (1982);, 10.1051/jphys:0198200430110161700 J. Phys. (Paris) 45, 637 (1984), 10.1051/jphys:01984004504063700], we separate the contributions of vacuum fluctuations and radiation reaction (source) field to the resonance interaction energy between the two atoms and show that only the source field contributes to the interatomic interaction, while vacuum field fluctuations do not. By considering specific geometric configurations of the two-atom system with respect to the mirror and specific choices of dipole orientations, we show that the presence of the mirror significantly affects the resonance interaction energy and that different features appear with respect to the case of atoms in free space, for example, a change in the spatial dependence of the interaction. Our findings also suggest that the presence of a boundary can be exploited to tailor and control the resonance interaction between two atoms, as well as the related energy transfer process. The possibility of observing these phenomena is also discussed.

  7. 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.

  8. Cooperative fluorescence from a strongly driven dilute cloud of atoms

    DEFF Research Database (Denmark)

    Ott, Johan Raunkjær; Wubs, Martijn; Lodahl, Peter

    2013-01-01

    We investigate cooperative fluorescence in a dilute cloud of strongly driven two-level emitters. Starting from the Heisenberg equations of motion, we compute the first-order scattering corrections to the saturation of the excited-state population and to the resonance-fluorescence spectrum, which...... both require going beyond the state-of-the-art linear-optics approach to describe collective phenomena. A dipole blockade is observed due to long-range dipole-dipole coupling that vanishes at stronger driving fields. Furthermore, we compute the inelastic component of the light scattered by a cloud...

  9. A Rotating-Bears Optical Dipole Trap for Cold Aatoms

    International Nuclear Information System (INIS)

    Friedman, N.; Ozeri, R.; Khaykovich, L.; Davidson, N.

    1999-01-01

    In the last few years, several optical dipole traps for cold atoms were demonstrated and used to study cold atomic collisions, long atomic coherence times and quantum collective effects. Blue-detuned dipole traps, where repulsive light forces confines atoms mostly in dark, offer long storage, and photon-scattering times, combined with strong confinement forces. Unfortunately, such blue-detuned dipole traps involve complicated light intensity distributions that require either multiple laser beams or complicated phase elements. Here, we propose and demonstrate a novel configuration for a single-beam blue-detuned dipole trap, which enables larger trapping volume, and fast temporal changes in the trap size and shape. Our trap consists of a tightly-focused laser beam which is rapidly rotated (with rotation frequency up to 400 khz) with two orthogonal acousto optical scanners. For very high rotation frequencies the atoms feel a time-averaged static dipole potential. Therefore, when the radius of rotation is larger than the beam size, a dark volume which is completely surrounded by light is obtained around the focal region. By changing the rotation radius and the trapping laser intensity and detuning, the trap dimensions and oscillation frequency could be changed over a large parameter range. In particular trap diameters were changed between 50 to 220 microns and trap length was changed between 3.5 to 16 mm. ∼10 6 atoms were loaded into the rotating-beam dipole trap from a magneto optical trap. The density of the trapped atoms was 4x10 10 atoms/cm 3 ,their temperature was -6 pK. and the trap (1/e) lifetime was 0.65 sec, limited by collisions with background atoms. When the rotation frequency was decreased below the oscillation frequency of the atoms in the trap, the trap became unstable, and a sharp reduction of the trap lifetime was observed, in agreement with our theoretical analysis. Finally, we demonstrated adiabatic compression of atoms in the trap by decreasing

  10. A new method to position the APS dipoles with the use of a laser tracker

    International Nuclear Information System (INIS)

    Friedsam, H.; Penicka, J.

    1994-01-01

    The alignment requirements for the synchrotron light sources have increased to the limit of today's alignment techniques. Some components such as dipoles can only be positioned after having obtained a three-dimensional outline of the as-built magnet. The laser tracking system provides the unique opportunity to map the dipole gap and relate the information to the outside reference marks for the placement of the magnet. In this case the Leica SMART 310 laser tracker is used as a 3D coordinate measuring system that provides the necessary information of twist, roll, sag, and gap changes over the full dipole length. On the basis of this information the best fitting plane is calculated to obtain the average roll angle for the positioning of the dipole. This paper describes the basic principal of this alignment technique and demonstrates the achieved results with examples

  11. 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

  12. 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)

  13. 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)

  14. 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

  15. Investigating source directivity for the 2012 Ml5.9 Emilia (Northern Italy) earthquake by jointly using High-rate GPS and Strong motion data

    Science.gov (United States)

    Avallone, A.; Herrero, A.; Latorre, D.; Rovelli, A.; D'Anastasio, E.

    2012-12-01

    On May, 20th 2012, the Ferrara and Modena provinces (Emilia Romagna, Northern Italy) were struck by a moderate magnitude earthquake (Ml 5.9). The focal mechanism is consistent with a ~E-W-striking thrust fault. The mainshock was recorded by 29 high-rate sampling (1-Hz) continuous GPS (HRGPS) stations belonging to scientific or commercial networks and by 55 strong motion (SM) stations belonging to INGV (Istituto Nazionale di Geofisica e Vulcanologia) and RAN (Rete Accelerometrica Nazionale) networks, respectively. The spatial distribution of both HRGPS and SM stations with respect to the mainshock location allows a satisfactory azimuthal coverage of the area. To investigate directivity effects during the mainshock occurrence, we analyze the spatial variation of the peak ground displacement (PGD) measured either for HRGPS or SM sites, using different methods. For each HRGPS and SM site, we rotated the horizontal time series to the azimuth direction and we estimated the GPS-related and the SM-related peak ground displacement (G-PGD and S-PGD, respectively) retrieved by transverse component. However, in contrast to GPS displacements, the double integration of the SM data can be affected by the presence of drifts and, thus, they have to be corrected by quasi-manual procedures. To more properly compare the G-PGDs to the S-PGDs, we used the response spectrum. A response spectrum is simply the response of a series of oscillators of varying natural frequency, that are forced into motion by the same input. The asymptotic value of the displacement response spectrum is the peak ground displacement. Thus, for each HRGPS and SM site, we computed the value of this asymptotic trend (G-PGDrs and S-PGDrs, respectively). This method allows simple automatic procedures. The consistency of the PGDs derived from HRGPS and SM is also evaluated for sites where the two instruments are collocated. The PGDs obtained by the two different methods and the two different data types suggest a

  16. 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.

  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. 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....

  19. 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

  20. Enhanced Wireless Power Transmission Using Strong Paramagnetic Response.

    Science.gov (United States)

    Ahn, Dukju; Kiani, Mehdi; Ghovanloo, Maysam

    2014-03-01

    A method of quasi-static magnetic resonant coupling has been presented for improving the power transmission efficiency (PTE) in near-field wireless power transmission, which improves upon the state of the art. The traditional source resonator on the transmitter side is equipped with an additional resonator with a resonance frequency that is tuned substantially higher than the magnetic field excitation frequency. This additional resonator enhances the magnetic dipole moment and the effective permeability of the power transmitter, owing to a phenomenon known as the strong paramagnetic response. Both theoretical calculations and experimental results show increased PTE due to amplification of the effective permeability. In measurements, the PTE was improved from 57.8% to 64.2% at the nominal distance of 15 cm when the effective permeability was 2.6. The power delivered to load was also improved significantly, with the same 10 V excitation voltage, from 0.38 to 5.26 W.

  1. 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

  2. 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...

  3. 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.)

  4. 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)

  5. 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.)

  6. 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

  7. 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...

  8. 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

  9. Indian Ocean dipole modulated wave climate of eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Anoop, T.R.; SanilKumar, V.; Shanas, P.R.; Glejin, J.; Amrutha, M.M.

    –378, 2016 www.ocean-sci.net/12/369/2016/ doi:10.5194/os-12-369-2016 © Author(s) 2016. CC Attribution 3.0 License. Indian Ocean Dipole modulated wave climate of eastern Arabian Sea T. R. Anoop1, V. Sanil Kumar1, P. R. Shanas1,2, J. Glejin1, and M. M. Amrutha1... are available on the website of the Japanese Agency of Marine–Earth Science and Technology (www.jamstec.go.jp). The tropical IO displays strong inter-annual climate vari- ability associated with the El Niño–Southern Oscillation (ENSO) and the IOD (Murtugudde et...

  10. Sources

    International Nuclear Information System (INIS)

    Duffy, L.P.

    1991-01-01

    This paper discusses the sources of radiation in the narrow perspective of radioactivity and the even narrow perspective of those sources that concern environmental management and restoration activities at DOE facilities, as well as a few related sources. Sources of irritation, Sources of inflammatory jingoism, and Sources of information. First, the sources of irritation fall into three categories: No reliable scientific ombudsman to speak without bias and prejudice for the public good, Technical jargon with unclear definitions exists within the radioactive nomenclature, and Scientific community keeps a low-profile with regard to public information. The next area of personal concern are the sources of inflammation. This include such things as: Plutonium being described as the most dangerous substance known to man, The amount of plutonium required to make a bomb, Talk of transuranic waste containing plutonium and its health affects, TMI-2 and Chernobyl being described as Siamese twins, Inadequate information on low-level disposal sites and current regulatory requirements under 10 CFR 61, Enhanced engineered waste disposal not being presented to the public accurately. Numerous sources of disinformation regarding low level radiation high-level radiation, Elusive nature of the scientific community, The Federal and State Health Agencies resources to address comparative risk, and Regulatory agencies speaking out without the support of the scientific community

  11. Development of High-Resolution Dynamic Dust Source Function - A Case Study with a Strong Dust Storm in a Regional Model

    Science.gov (United States)

    Kim, Dongchul; Chin, Mian; Kemp, Eric M.; Tao, Zhining; Peters-Lidard, Christa D.; Ginoux, Paul

    2017-01-01

    A high-resolution dynamic dust source has been developed in the NASA Unified-Weather Research and Forecasting (NU-WRF) model to improve the existing coarse static dust source. In the new dust source map, topographic depression is in 1-km resolution and surface bareness is derived using the Normalized Difference Vegetation Index (NDVI) data from Moderate Resolution Imaging Spectroradiometer (MODIS). The new dust source better resolves the complex topographic distribution over the Western United States where its magnitude is higher than the existing, coarser resolution static source. A case study is conducted with an extreme dust storm that occurred in Phoenix, Arizona in 0203 UTC July 6, 2011. The NU-WRF model with the new high-resolution dynamic dust source is able to successfully capture the dust storm, which was not achieved with the old source identification. However the case study also reveals several challenges in reproducing the time evolution of the short-lived, extreme dust storm events.

  12. Development of High-Resolution Dynamic Dust Source Function -A Case Study with a Strong Dust Storm in a Regional Model.

    Science.gov (United States)

    Kim, Dongchul; Chin, Mian; Kemp, Eric M; Tao, Zhining; Peters-Lidard, Christa D; Ginoux, Paul

    2017-06-01

    A high-resolution dynamic dust source has been developed in the NASA Unified-Weather Research and Forecasting (NU-WRF) model to improve the existing coarse static dust source. In the new dust source map, topographic depression is in 1-km resolution and surface bareness is derived using the Normalized Difference Vegetation Index (NDVI) data from Moderate Resolution Imaging Spectroradiometer (MODIS). The new dust source better resolves the complex topographic distribution over the Western United States where its magnitude is higher than the existing, coarser resolution static source. A case study is conducted with an extreme dust storm that occurred in Phoenix, Arizona in 02-03 UTC July 6, 2011. The NU-WRF model with the new high-resolution dynamic dust source is able to successfully capture the dust storm, which was not achieved with the old source identification. However the case study also reveals several challenges in reproducing the time evolution of the short-lived, extreme dust storm events.

  13. Magnetic dipole strength in {sup 128}Xe and {sup 134}Xe in the spin-flip resonance region

    Energy Technology Data Exchange (ETDEWEB)

    Massarczyk, R. [Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Rusev, G. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Schwengner, R.; Doenau, F. [Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Bathia, C. [McMaster University, Hamilton, Ontario L8S4L8 (Canada); Gooden, M.E.; Kelley, J.H. [Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); North Carolina State University, Raleigh, NC 27695 (United States); Tonchev, A.P. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Tornow, W. [Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); Duke University, Durham, NC 27708 (United States)

    2015-07-01

    The magnetic dipole strength in the energy region of the spin-flip resonance is investigated in {sup 128}Xe and {sup 134}Xe using quasimonoenergetic and linearly polarized γ-ray beams at the High-Intensity γ-Ray Source facility in Durham, North Carolina, USA. Absorption cross sections were deduced for the magnetic and electric and dipole strength distributions separately for various intervals of excitation energy, including the strength of states in the unresolved quasicontinuum. The magnetic dipole strength distributions show structures resembling a resonance in the spin-flip region around an excitation energy of 8 MeV. The electric dipole strength distributions obtained from the present experiments are in agreement with the ones deduced from an earlier experiment using broad-band bremsstrahlung instead of a quasimonoenergetic beam. The experimental magnetic and electric dipole strength distributions are compared with model predictions.

  14. Molecular physics. Production of trilobite Rydberg molecule dimers with kilo-Debye permanent electric dipole moments.

    Science.gov (United States)

    Booth, D; Rittenhouse, S T; Yang, J; Sadeghpour, H R; Shaffer, J P

    2015-04-03

    Permanent electric dipole moments are important for understanding symmetry breaking in molecular physics, control of chemical reactions, and realization of strongly correlated many-body quantum systems. However, large molecular permanent electric dipole moments are challenging to realize experimentally. We report the observation of ultralong-range Rydberg molecules with bond lengths of ~100 nanometers and kilo-Debye permanent electric dipole moments that form when an ultracold ground-state cesium (Cs) atom becomes bound within the electronic cloud of an extended Cs electronic orbit. The electronic character of this hybrid class of "trilobite" molecules is dominated by degenerate Rydberg manifolds, making them difficult to produce by conventional photoassociation. We used detailed coupled-channel calculations to reproduce their properties quantitatively. Our findings may lead to progress in ultracold chemistry and strongly correlated many-body physics. Copyright © 2015, American Association for the Advancement of Science.

  15. Algebraic Reconstruction of Current Dipoles and Quadrupoles in Three-Dimensional Space

    Directory of Open Access Journals (Sweden)

    Takaaki Nara

    2013-01-01

    Full Text Available This paper presents an algebraic method for an inverse source problem for the Poisson equation where the source consists of dipoles and quadrupoles. This source model is significant in the magnetoencephalography inverse problem. The proposed method identifies the source parameters directly and algebraically using data without requiring an initial parameter estimate or iterative computation of the forward solution. The obtained parameters could be used for the initial solution in an optimization-based algorithm for further refinement.

  16. 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.

  17. Investigation of the source size and strong interaction with the femtoscopic correlations of baryons and antibaryons in heavy-ion collisions registered by ALICE

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00508100

    The strong interaction is one of the four fundamental forces of nature. It binds together quarks inside protons and neutrons (which are example of baryons - particles composed of three quarks) and assures the stability of the atomic nucleus. Parameters describing the strong potential are also crucial for the neutron stars models used in astrophysics. What is more, a precise study of strongly interacting particles may help to better understand the process of baryon annihilation. The current knowledge of the strong interactions between baryons other than nucle- ons is limited - there exist only a few measurements of the cross sections for pairs of (anti)baryons. The reason is that in many cases it is not possible to perform scattering experiments with beams of particles and antiparticles, as the exotic matter (such as Λ, Ξ or Σ baryons) is very shot-living. This issue can be solved thanks to the recent particle colliders like the Large Hadron Collider and experiments dedicated to study the heavy-ion collisio...

  18. A visualization of null geodesics for the bonnor massive dipole

    Directory of Open Access Journals (Sweden)

    G. Andree Oliva Mercado

    2015-08-01

    Full Text Available In this work we simulate null geodesics for the Bonnor massive dipole metric by implementing a symbolic-numerical algorithm in Sage and Python. This program is also capable of visualizing in 3D, in principle, the geodesics for any given metric. Geodesics are launched from a common point, collectively forming a cone of light beams, simulating a solid-angle section of a point source in front of a massive object with a magnetic field. Parallel light beams also were considered, and their bending due to the curvature of the space-time was simulated.

  19. Investigation of the Pygmy Dipole Resonance in {sup 60}Ni

    Energy Technology Data Exchange (ETDEWEB)

    Fritzsche, Matthias; Pietralla, Norbert; Romig, Christopher; Savran, Deniz; Sonnabend, Kerstin [Institut fuer Kernphysik, Technische Universitaet, Darmstadt (Germany); Rusev, Gencho; Tonchev, Anton P.; Tornow, Werner; Weller, Henry R. [Triangle Universities Nuclear Laboratory, Duke University, Durham, NC (United States); Zilges, Andreas [Institut fuer Kernphysik, Universitaet Koeln (Germany)

    2009-07-01

    At the High Intensity Photon Setup (HIPS) at S-DALINAC in Darmstadt {sup 60}Ni was investigated with unpolarized bremsstrahlung with energies up to 8.0 MeV and 9.9 MeV, respectively. Determination of spin and parity quantum numbers and absolute transition strengths was possible, using HPGe detectors placed under different angles. To assign also parity quantum numbers, the polarized photon beam of the High Intensity Gamma Source (HI{gamma}S) at Duke University was used. With the combined results, evidence of the Pygmy Dipole Resonance in {sup 60}Ni was found.

  20. Impedance Localization Measurements using AC Dipoles in the LHC

    CERN Document Server

    Biancacci, Nicolo; Papotti, Giulia; Persson, Tobias; Salvant, Benoit; Tomás, Rogelio

    2016-01-01

    The knowledge of the LHC impedance is of primary importance to predict the machine performance and allow for the HL-LHC upgrade. The developed impedance model can be benchmarked with beam measurements in order to assess its validity and limit. This is routinely done, for example, moving the LHC collimator jaws and measuring the induced tune shift. In order to localize possible unknown impedance sources, the variation of phase advance with intensity between beam position monitors can be measured. In this work we will present the impedance localization measurements performed at injection in the LHC using AC dipoles as exciter as well as the underlying theory.

  1. Probing CP Violation with the Deuteron Electric Dipole Moment

    CERN Document Server

    Lebedev, Oleg; Pospelov, Maxim; Ritz, Adam; Lebedev, Oleg; Olive, Keith A.; Pospelov, Maxim; Ritz, Adam

    2004-01-01

    We present an analysis of the electric dipole moment (EDM) of the deuteron as induced by CP-violating operators of dimension 4, 5 and 6 including theta QCD, the EDMs and color EDMs of quarks, four-quark interactions and the Weinberg operator. We demonstrate that the precision goal of the EDM Collaboration's proposal to search for the deuteron EDM, (1-3)\\times 10^{-27} e cm, will provide an improvement in sensitivity to these sources of one-two orders of magnitude relative to the existing bounds. We consider in detail the level to which CP-odd phases can be probed within the MSSM.

  2. Electric dipole moment searches using the isotope 129-xenon

    Energy Technology Data Exchange (ETDEWEB)

    Kuchler, Florian

    2014-11-13

    Two new complementary experiments searching for a permanent electric dipole moment (EDM) of 129-xenon are presented. Besides demonstration of a sensitivity improvement by employing established methods and a highly sensitive SQUID detection system the progress towards a novel measurement approach is discussed. The new method introduces time-varying electric fields and a liquid hyper-polarized xenon sample with a potential improvement in sensitivity of three orders of magnitude. The search for EDMs is motivated by their symmetry-breaking nature. A non-zero EDM provides a new source of CP violation to solve the mystery of the huge excess of matter over anti-matter in our Universe.

  3. 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...

  4. 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....

  5. sources

    Directory of Open Access Journals (Sweden)

    Shu-Yin Chiang

    2002-01-01

    Full Text Available In this paper, we study the simplified models of the ATM (Asynchronous Transfer Mode multiplexer network with Bernoulli random traffic sources. Based on the model, the performance measures are analyzed by the different output service schemes.

  6. 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.

  7. Radiation phase of a dipole field

    International Nuclear Information System (INIS)

    Shunovsky, A.S.

    1998-01-01

    In the case of a dipole electromagnetic radiation, the operator of the 'radiation phase' is defined. It is shown that this operator has a discrete spectrum with eigenvalues, lying in the segment [0,2π]. Some properties of the radiation phase and polarization are discussed. Seventy years of investigation of the problem of quantum phase led to the conclusion that there is no unique quantum variable, determining universally the measured phase properties of electromagnetic radiation. The operator constructions, describing cosine and sine of the phase, could be different schemes of measurement. This fact has accurately been confirmed by a number of recent experiments. Thus, it seems to be quite plausible that the quantum phase properties of an electromagnetic radiation are determined by interaction photons with a macroscopic detecting device. It is pertinent to ask the following question. Are the quantum phase properties of radiation completely determined by such an interaction or the photons have their own inherent phase properties which might be measured even if they are modified by interaction with a detecting device? The universally recognized fact is that the vacuum state of field is degenerated with respect to phase. If a quantum radiation has its inherent phase properties, it means that the degeneration is taken off in the process of generation which is an interaction of the vacuum field with excited states of atoms or molecules. By virtue of this picture proposed in, what all one can expect is that the inherent quantum phase properties of radiation are completely determined by a source via the conservation laws, describing the generation process. Even in this way, it seems to determine a unique quantum phase of radiation. As a matter of fact, there are two conservation laws, admitting a nontrivial angular dependence

  8. 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...

  9. A proposed method of measuring the electric-dipole moment of the neutron by ultracold neutron interferometry

    International Nuclear Information System (INIS)

    Freedman, M.S.; Peshkin, M.; Ringo, G.R.; Dombeck, T.W.

    1989-08-01

    The use of an ultracold neutron interferometer incorporating an electrostatic accelerator having a strong electric field gradient to accelerate neutrons by their possible electric dipole moment is proposed as a method of measuring the neutron electric dipole moment. The method appears to have the possibility of extending the sensitivity of the measurement by several orders of magnitude, perhaps to 10 -30 e-cm. 9 refs., 3 figs

  10. Mapping of auroral kilometric radiation sources to the aurora

    International Nuclear Information System (INIS)

    Huff, R.L.; Calvert, W.; Craven, J.D.; Frank, L.A.; Gurnett, D.A.

    1988-01-01

    Auroral kilometric radiation (AKR) and optical auroral emissions are observed simultaneously using plasma wave instrumentation and auroral imaging photometers acrried on the DE 1 spacecraft. The DE 1 plasma wave instrument measures the relative phase of signals from orthogonal electric dipole antennas, and from these measurements, apparent source directions can be determined with a high degree of precision. Wave data are analyzed for several strong AKR events, and source directions are determined for several emission frequencies. By assuming that the AKR originates at cyclotron resonant altitudes, a condidate source field line is identified. When the selected source field line is traced down to auroral altitudes on the concurrent DE 1 auroral image, a striking correspondence between the AKR source field line and localized auroral features is produced. The magnetic mapping study provides strong evidence that AKR sources occur on field lines associated with discrete auroral arcs, and it provides confirmation that AKR is generated near the electron cyclotron frequency

  11. Chirality Driven by Magnetic Dipole Response for Demultiplexing of Surface Waves

    DEFF Research Database (Denmark)

    Sinev, Ivan S.; Bogdanov, Andrey A.; Komissarenko, Filipp E.

    2017-01-01

    chiral response with strong spectral dependence due to the interference of electric and magnetic dipole momenta when placed in the vicinity of the metal-air interface. Remarkably, chiral behaviour in the proposed scheme does not require elliptical polarization of the pump beam or the geometric chirality...

  12. Unraveling models of CP violation through electric dipole moments of light nuclei

    NARCIS (Netherlands)

    Dekens, W.; Vries, J. de; Bsaisou, J.; Bernreuther, W.; Hanhart, C.; Meißner, Ulf-G; Nogga, A.; Wirzba, A.

    2014-01-01

    We show that the proposed measurements of the electric dipole moments of light nuclei in storage rings would put strong constraints on models of flavor-diagonal CP violation. Our analysis is exemplified by a comparison of the Standard Model including the QCD theta term, the minimal left-right

  13. AE monitoring instrumentation for high performance superconducting dipoles and quadrupoles, Phase 2

    Science.gov (United States)

    Iwasa, Y.

    1986-01-01

    In the past year and a half, attention has been focused on the development of instrumentation for on-line monitoring of high-performance superconducting dipoles and quadrupoles. This instrumentation has been completed and satisfactorily demonstrated on a prototype Fermi dipole. Conductor motion is the principal source of acoustic emission (AE) and the major cause of quenches in the dipole, except during the virgin run when other sources are also present. The motion events are mostly microslips. The middle of the magnet is most susceptible to quenches. This result agrees with the peak field location in the magnet. In the virgin state the top and bottom of the magnet appeared acoustically similar but diverged after training, possibly due to minute structural asymmetry, for example differences in clamping and welding strength; however, the results do not indicate any major structural defects. There is good correlation between quench current and AE starting current. The correlation is reasonable if mechanical disturbances are indeed responsible for quench. Based on AE cumulative history, the average frictional power dissipation in the whole dipole winding is estimated to be approx. 10 (MU)W cm(-3). We expect to implement the following in the next phase of this project: Application of room-temperature techniques to detecting structural defects in the dipole; application of the system to other dipoles and quadrupoles in the same series to compare their performances; and further investigation of AE starting current approx. quench current relationship. Work has begun on the room temperature measurements. Preliminary Stress Wave Factor measurements have been made on a model dipole casing.

  14. Quantification of Greenhouse Gas Emission Rates from strong Point Sources by Space-borne IPDA Lidar Measurements: Results from a Sensitivity Analysis Study

    Science.gov (United States)

    Ehret, G.; Kiemle, C.; Rapp, M.

    2017-12-01

    The practical implementation of the Paris Agreement (COP21) vastly profit from an independent, reliable and global measurement system of greenhouse gas emissions, in particular of CO2, in order to complement and cross-check national efforts. Most fossil-fuel CO2 emitters emanate from large sources such as cities and power plants. These emissions increase the local CO2 abundance in the atmosphere by 1-10 parts per million (ppm) which is a signal that is significantly larger than the variability from natural sources and sinks over the local source domain. Despite these large signals, they are only sparsely sampled by the ground-based network which calls for satellite measurements. However, none of the existing and forthcoming passive satellite instruments, operating in the NIR spectral domain, can measure CO2 emissions at night time or in low sunlight conditions and in high latitude regions in winter times. The resulting sparse coverage of passive spectrometers is a serious limitation, particularly for the Northern Hemisphere, since these regions exhibit substantial emissions during the winter as well as other times of the year. In contrast, CO2 measurements by an Integrated Path Differential Absorption (IPDA) Lidar are largely immune to these limitations and initial results from airborne application look promising. In this study, we discuss the implication for a space-borne IPDA Lidar system. A Gaussian plume model will be used to simulate the CO2-distribution of large power plants downstream to the source. The space-borne measurements are simulated by applying a simple forward model based on Gaussian error distribution. Besides the sampling frequency, the sampling geometry (e.g. measurement distance to the emitting source) and the error of the measurement itself vastly impact on the flux inversion performance. We will discuss the results by incorporating Gaussian plume and mass budget approaches to quantify the emission rates.

  15. Effective Induction Heating around Strongly Magnetized Stars

    Science.gov (United States)

    Kislyakova, K. G.; Fossati, L.; Johnstone, C. P.; Noack, L.; Lüftinger, T.; Zaitsev, V. V.; Lammer, H.

    2018-05-01

    Planets that are embedded in the changing magnetic fields of their host stars can experience significant induction heating in their interiors caused by the planet’s orbital motion. For induction heating to be substantial, the planetary orbit has to be inclined with respect to the stellar rotation and dipole axes. Using WX UMa, for which the rotation and magnetic axes are aligned, as an example, we show that for close-in planets on inclined orbits, induction heating can be stronger than the tidal heating occurring inside Jupiter’s satellite Io; namely, it can generate a surface heat flux exceeding 2 W m‑2. An internal heating source of such magnitude can lead to extreme volcanic activity on the planet’s surface, possibly also to internal local magma oceans, and to the formation of a plasma torus around the star aligned with the planetary orbit. A strongly volcanically active planet would eject into space mostly SO2, which would then dissociate into oxygen and sulphur atoms. Young planets would also eject CO2. Oxygen would therefore be the major component of the torus. If the O I column density of the torus exceeds ≈1012 cm‑2, the torus could be revealed by detecting absorption signatures at the position of the strong far-ultraviolet O I triplet at about 1304 Å. We estimate that this condition is satisfied if the O I atoms in the torus escape the system at a velocity smaller than 1–10 km s‑1. These estimates are valid also for a tidally heated planet.

  16. Can measurements of electric dipole moments determine the seesaw parameters?

    International Nuclear Information System (INIS)

    Demir, Durmus A.; Farzan, Yasaman

    2005-01-01

    In the context of the supersymmetrized seesaw mechanism embedded in the Minimal Supersymmetric Standard Model (MSSM), complex neutrino Yukawa couplings can induce Electric Dipole Moments (EDMs) for the charged leptons, providing an additional route to seesaw parameters. However, the complex neutrino Yukawa matrix is not the only possible source of CP violation. Even in the framework of Constrained MSSM (CMSSM), there are additional sources, usually attributed to the phases of the trilinear soft supersymmetry breaking couplings and the mu-term, which contribute not only to the electron EDM but also to the EDMs of neutron and heavy nuclei. In this work, by combining bounds on various EDMs, we analyze how the sources of CP violation can be discriminated by the present and planned EDM experiments

  17. Direct interferometric measurement of the atomic dipole phase in high-order harmonic generation

    International Nuclear Information System (INIS)

    Chiara Corsi; Angela Pirri; Emiliano Sali

    2006-01-01

    Complete test of publication follows. For low gas densities and negligible ionization, the so-called atomic dipole phase, connected with the electronic dynamics involved in the generation process, is the main source of phase modulation and incoherence of high-order harmonics. To accurately determine these laser-intensity-induced phase shifts is therefore of great importance, both for the possible spectroscopic applications of harmonics and for the controlled generation of attosecond pulses. In a semiclassical description, only two electronic trajectories contribute to generate plateau harmonics during each pump optical half-cycle. Electrons appearing in the continuum by tunnel ionization may follow two different quantum paths, namely a long (l) and a short (s) trajectory before recombination. According to the SFA approximation, the harmonic of q th order acquires a phase proportional to the electronic classical action, and simply given by: ψ 0 j (r,t) -α q j I(r,t) with j = l, s where α q j are non-linear phase coefficients, roughly proportional to the time that the originating electron spends in the continuum before recombination. The space and time variation of the laser intensity (I(r,t), causes just a little phase modulation for the s-trajectory harmonic component, while the l-trajectory component becomes strongly chirped and spatially defocused; this gives rise to two spatially-separated regions having different temporal coherence. Here we report the first direct measurement of such atomic dipole phase in the process of high-order harmonic generation. Differently from previous measurements based in the most natural way, i.e., by interferometry. Two phase-locked pump pulses generate two phase-locked harmonic pulses in two nearby positions in a gas jet; one of them is used as a fixed phase reference while the generating intensity of the other is varied. The shift of the XUV interference fringes observed in the far field then gives a direct estimate of the

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.)

  5. Magnetic properties of smooth terminating dipole bands in 110,112Te

    International Nuclear Information System (INIS)

    Evans, A.O.; Paul, E.S.; Boston, A.J.; Chantler, H.J.; Chiara, C.J.; Devlin, M.; Fletcher, A.M.; Fossan, D.B.; LaFosse, D.R.; Lane, G.J.; Lee, I.Y.; Macchiavelli, A.O.; Nolan, P.J.; Sarantites, D.G.; Sears, J.M.; Semple, A.T.; Smith, J.F.; Starosta, K.; Vaman, C.; Afanasjev, A.V.; Ragnarsson, I.

    2006-01-01

    Three strongly coupled sequences have been established in 110,112 Te up to high spins. They are interpreted in terms of deformed structures built on proton 1-particle-1-hole excitations that reach termination at I∼40-bar . This is the first observation of smooth terminating dipole structures in this mass region. Lifetime measurements have allowed the extraction of experimental B(M1;I->I-1) and B(E2;I->I-2) reduced transition rates for one of the dipole bands in 110 Te. The results support the deformed interpretation

  6. 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

  7. 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...

  8. 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.

  9. 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

  10. 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.

  11. 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)

  12. 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.

  13. Tunable subwavelength hot spot of dipole nanostructure based on VO2 phase transition.

    Science.gov (United States)

    Park, Jun-Bum; Lee, Il-Min; Lee, Seung-Yeol; Kim, Kyuho; Choi, Dawoon; Song, Eui Young; Lee, Byoungho

    2013-07-01

    We propose a novel approach to generate and tune a hot spot in a dipole nanostructure of vanadium dioxide (VO2) laid on a gold (Au) substrate. By inducing a phase transition of the VO2, the spatial and spectral distributions of the hot spot generated in the feed gap of the dipole can be tuned. Our numerical simulation based on a finite-element method shows a strong intensity enhancement difference and tunability near the wavelength of 678 nm, where the hot spot shows 172-fold intensity enhancement when VO2 is in the semiconductor phase. The physical mechanisms of forming the hot spots at the two-different phases are discussed. Based on our analysis, the effects of geometric parameters in our dipole structure are investigated with an aim of enhancing the intensity and the tunability. We hope that the proposed nanostructure opens up a practical approach for the tunable near-field nano-photonic devices.

  14. High-order above-threshold ionization beyond the electric dipole approximation

    Science.gov (United States)

    Brennecke, Simon; Lein, Manfred

    2018-05-01

    Photoelectron momentum distributions from strong-field ionization are calculated by numerical solution of the one-electron time-dependent Schrödinger equation for a model atom including effects beyond the electric dipole approximation. We focus on the high-energy electrons from rescattering and analyze their momentum component along the field propagation direction. We show that the boundary of the calculated momentum distribution is deformed in accordance with the classical three-step model including the beyond-dipole Lorentz force. In addition, the momentum distribution exhibits an asymmetry in the signal strengths of electrons emitted in the forward/backward directions. Taken together, the two non-dipole effects give rise to a considerable average forward momentum component of the order of 0.1 a.u. for realistic laser parameters.

  15. Spherical active coated nano-particles – impact of the electric Hertzian dipole orientation

    DEFF Research Database (Denmark)

    Arslanagic, Samel; Mostafavi, M.; Malureanu, Radu

    2011-01-01

    Spherical active coated nano-particles comprised of a silica nano-cylinder core covered with a plasmonic nano-shell are investigated with regard to their near- and far-field properties. The source of excitation is taken to be that of a tangential or a radial electric Hertizan dipole while three...

  16. The discrete-dipole-approximation code ADDA: capabilities and known limitations

    NARCIS (Netherlands)

    Yurkin, M.A.; Hoekstra, A.G.

    2011-01-01

    The open-source code ADDA is described, which implements the discrete dipole approximation (DDA), a method to simulate light scattering by finite 3D objects of arbitrary shape and composition. Besides standard sequential execution, ADDA can run on a multiprocessor distributed-memory system,

  17. Effect of electromagnetic dipole dark matter on energy transport in the solar interior

    Energy Technology Data Exchange (ETDEWEB)

    Geytenbeek, Ben; Rao, Soumya; White, Martin; Williams, Anthony G. [ARC Centre of Excellence for Particle Physics at the Terascale and CSSM, Department of Physics, University of Adelaide, Adelaide, South Australia 5005 (Australia); Scott, Pat; Vincent, Aaron C. [Department of Physics, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom); Serenelli, Aldo, E-mail: bg364@cam.ac.uk, E-mail: soumya.rao@ncbj.gov.pl, E-mail: p.scott@imperial.ac.uk, E-mail: aldos@ice.csic.es, E-mail: aaron.vincent@imperial.ac.uk, E-mail: martin.white@adelaide.edu.au, E-mail: anthony.williams@adelaide.edu.au [Institute of Space Sciences (IEEC-CSIC), Campus UAB, Carrer de Can Magrans s/n, 08193, Barcelona (Spain)

    2017-03-01

    In recent years, a revised set of solar abundances has led to a discrepancy in the sound-speed profile between helioseismology and theoretical solar models. Conventional solutions require additional mechanisms for energy transport within the Sun. Vincent et al. have recently suggested that dark matter with a momentum or velocity dependent cross section could provide a solution. In this work, we consider three models of dark matter with such cross sections and their effect on the stellar structure. In particular, the three models incorporate dark matter particles interacting through an electromagnetic dipole moment: an electric dipole, a magnetic dipole or an anapole. Each model is implemented in the DarkStec stellar evolution program, which incorporates the effects of dark matter capture and heat transport within the solar interior. We show that dark matter with an anapole moment of ∼ 1 GeV{sup −2} or magnetic dipole moment of ∼ 10{sup −3}μ {sub p} can improve the sound-speed profile, small frequency separations and convective zone radius with respect to the Standard Solar Model. However, the required dipole moments are strongly excluded by direct detection experiments.

  18. Geomagnetic dipole strength and reversal rate over the past two million years.

    Science.gov (United States)

    Valet, Jean-Pierre; Meynadier, Laure; Guyodo, Yohan

    2005-06-09

    Independent records of relative magnetic palaeointensity from sediment cores in different areas of the world can be stacked together to extract the evolution of the geomagnetic dipole moment and thus provide information regarding the processes governing the geodynamo. So far, this procedure has been limited to the past 800,000 years (800 kyr; ref. 3), which does not include any geomagnetic reversals. Here we present a composite curve that shows the evolution of the dipole moment during the past two million years. This reconstruction is in good agreement with the absolute dipole moments derived from volcanic lavas, which were used for calibration. We show that, at least during this period, the time-averaged field was higher during periods without reversals but the amplitude of the short-term oscillations remained the same. As a consequence, few intervals of very low intensity, and thus fewer instabilities, are expected during periods with a strong average dipole moment, whereas more excursions and reversals are expected during periods of weak field intensity. We also observe that the axial dipole begins to decay 60-80 kyr before reversals, but rebuilds itself in the opposite direction in only a few thousand years.

  19. An empirical assessment of near-source strong ground motion for a 6.6 m{sub b} (7.5 M{sub S}) earthquake in the Eastern United States

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Kenneth W

    1984-06-01

    To help assess the impact of the current U.S. Geological Survey position on the seismic safety of nuclear power plants in the Eastern United States (EUS), several techniques for estimating near-source strong ground motion for a Charleston size earthquake were evaluated. The techniques for estimating the near-source strong ground motion for a 6.6 m{sub b} (7.5 M{sub S}) in the Eastern United States which were assessed are methods based on site specific analyses, semi-theoretical scaling techniques, and intensity-based estimates. The first involves the statistical analysis of ground motion records from earthquakes and recording stations having the same general characteristics (earthquakes with magnitudes of 7.5 M{sub S} or larger, epicentral distances of 25 km or less, and sites of either soil or rock). Some recommendations for source and characterization scaling of the bias resulting primarily from an inadequate sample of near-source recordings from earthquakes of large magnitude are discussed. The second technique evaluated requires that semi-theoretical estimates of peak ground motion parameters for a 6.6 m{sub b} (7.5 M{sub S}) earthquake be obtained from scaling relations. Each relation uses a theoretical expression between peak acceleration magnitude and distance together with available strong motion data (majority coming from California) to develop a scaling relation appropriate for the Eastern United States. None of the existing ground motion models for the EUS include the potential effects of source or site characteristics. Adjustments to account for fault mechanisms, site topography, site geology, and the size and embedment of buildings are discussed. The final approach used relations between strong ground motion parameters and Modified Mercalli Intensity in conjunction with two methods to estimate peak parameters for a 6.6 m{sub s} (7.5 M{sub S}) earthquake. As with other techniques, adjustment of peak acceleration estimates are discussed. Each method

  20. 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.

  1. 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)

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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...

  9. 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

  10. 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)

  11. 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

  12. 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.

  13. 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.

  14. Neutron electric dipole moment and extension of the standard model

    International Nuclear Information System (INIS)

    Oshimo, Noriyuki

    2001-01-01

    A nonvanishing value for the electric dipole moment (EDM) of the neutron is a prominent signature for CP violation. The EDM induced by the Kobayashi-Maskawa mechanism of the standard model (SM) has a small magnitude and its detection will be very difficult. However, since baryon asymmetry of the universe cannot be accounted for by the SM, there should exist some other source of CP violation, which may generate a large magnitude for the EDM. One of the most hopeful candidates for physics beyond the SM is the supersymmetric standard model, which contains such sources of CP violation. This model suggests that the EDM has a magnitude not much smaller than the present experimental bounds. Progress in measuring the EDM provides very interesting information about extension of the SM. (author)

  15. Electric dipole moments as probes of new physics

    CERN Document Server

    Pospelov, M; Pospelov, Maxim; Ritz, Adam

    2005-01-01

    We review several aspects of flavour-diagonal CP violation, focussing on the role played by the electric dipole moments (EDMs) of leptons, nucleons, atoms and molecules, which consitute the source of several stringent constraints on new CP-violating physics. We dwell specifically on the calculational aspects of applying the hadronic EDM constraints, reviewing in detail the application of QCD sum-rules to the calculation of nucleon EDMs and CP-odd pion-nucleon couplings. We also consider the current status of EDMs in the Standard Model, and on the ensuing constraints on the underlying sources of CP-violation in physics beyond the Standard Model, focussing on weak-scale supersymmetry.

  16. 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

  17. Individual Low-Energy Toroidal Dipole State in Mg 24

    Science.gov (United States)

    Nesterenko, V. O.; Repko, A.; Kvasil, J.; Reinhard, P.-G.

    2018-05-01

    The low-energy dipole excitations in Mg 24 are investigated within the Skyrme quasiparticle random phase approximation for axial nuclei. The calculations with the force SLy6 reveal a remarkable feature: the lowest IπK =1-1 excitation (E =7.92 MeV ) in Mg 24 is a vortical toroidal state (TS) representing a specific vortex-antivortex realization of the well-known spherical Hill's vortex in a strongly deformed axial confinement. This is a striking example of an individual TS which can be much more easily discriminated in experiment than the toroidal dipole resonance embracing many states. The TS acquires the lowest energy due to the huge prolate axial deformation in Mg 24 . The result persists for different Skyrme parametrizations (SLy6, SVbas, SkM*). We analyze spectroscopic properties of the TS and its relation with the cluster structure of Mg 24 . Similar TSs could exist in other highly prolate light nuclei. They could serve as promising tests for various reactions to probe a vortical (toroidal) nuclear flow.

  18. Dipole-modified graphene with ultrahigh gas sensibility

    Science.gov (United States)

    Jia, Ruokun; Xie, Peng; Feng, Yancong; Chen, Zhuo; Umar, Ahmad; Wang, Yao

    2018-05-01

    This study reports the supramolecular assembly of functional graphene-based materials with ultrahigh gas sensing performances which are induced by charge transfer enhancement. Two typical Donor-π-Accepter (D-π-A) structure molecules 4-aminoquinoline (4AQ, μ = 3.17 Debye) and 4-hydroxyquinoline (4HQ, μ = 1.98 Debye), with different charge transfer enhancing effects, were selected to modify reduce oxide graphene (rGO) via supramolecular assembly. Notably, compared to the 4HQ-rGO, the 4AQ-rGO exhibits more significant increase of gas response (Ra/Rg = 3.79) toward 10 ppm NO2, which is ascribed to the larger dipole moment (μ) of 4AQ and hence the more intensive enhancing effect of charge transfer on the interface of rGO. Meanwhile, 4AQ-rGO sensors also reveal superior comprehensive gas sensing performances, including excellent gas sensing selectivity, linearity, repeatability and stability. It is believed that the present work demonstrates an effective supramolecular approach of modifying rGO with strong dipoles to significantly improve gas sensing properties of graphene-based materials.

  19. 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.

  20. 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.

  1. 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 ...

  2. Gluon structure function of a color dipole in the light-cone limit of lattice QCD

    International Nuclear Information System (INIS)

    Gruenewald, D.; Ilgenfritz, E.-M.; Pirner, H. J.

    2009-01-01

    We calculate the gluon structure function of a color dipole in near-light-cone SU(2) lattice QCD as a function of x B . The quark and antiquark are external nondynamical degrees of freedom which act as sources of the gluon string configuration defining the dipole. We compute the color dipole matrix element of transversal chromo-electric and chromo-magnetic field operators separated along a direction close to the light cone, the Fourier transform of which is the gluon structure function. As vacuum state in the pure glue sector, we use a variational ground state of the near-light-cone Hamiltonian. We derive a recursion relation for the gluon structure function on the lattice similar to the perturbative Dokshitzer-Gribov-Lipatov-Altarelli-Parisi equation. It depends on the number of transversal links assembling the Schwinger string of the dipole. Fixing the mean momentum fraction of the gluons to the 'experimental value' in a proton, we compare our gluon structure function for a dipole state with four links with the next-to-leading-order MRST 2002 and the CTEQ AB-0 parametrizations at Q 2 =1.5 GeV 2 . Within the systematic uncertainty we find rather good agreement. We also discuss the low x B behavior of the gluon structure function in our model calculation.

  3. 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...

  4. Towards space based verification of CO2 emissions from strong localized sources: fossil fuel power plant emissions as seen by a CarbonSat constellation

    Directory of Open Access Journals (Sweden)

    T. Krings

    2011-12-01

    Full Text Available Carbon dioxide (CO2 is the most important man-made greenhouse gas (GHG that cause global warming. With electricity generation through fossil-fuel power plants now being the economic sector with the largest source of CO2, power plant emissions monitoring has become more important than ever in the fight against global warming. In a previous study done by Bovensmann et al. (2010, random and systematic errors of power plant CO2 emissions have been quantified using a single overpass from a proposed CarbonSat instrument. In this study, we quantify errors of power plant annual emission estimates from a hypothetical CarbonSat and constellations of several CarbonSats while taking into account that power plant CO2 emissions are time-dependent. Our focus is on estimating systematic errors arising from the sparse temporal sampling as well as random errors that are primarily dependent on wind speeds. We used hourly emissions data from the US Environmental Protection Agency (EPA combined with assimilated and re-analyzed meteorological fields from the National Centers of Environmental Prediction (NCEP. CarbonSat orbits were simulated as a sun-synchronous low-earth orbiting satellite (LEO with an 828-km orbit height, local time ascending node (LTAN of 13:30 (01:30 p.m. LT and achieves global coverage after 5 days. We show, that despite the variability of the power plant emissions and the limited satellite overpasses, one CarbonSat has the potential to verify reported US annual CO2 emissions from large power plants (≥5 Mt CO2 yr−1 with a systematic error of less than ~4.9% and a random error of less than ~6.7% for 50% of all the power plants. For 90% of all the power plants, the systematic error was less than ~12.4% and the random error was less than ~13%. We additionally investigated two different satellite configurations using a combination of 5 CarbonSats. One achieves global coverage everyday but only samples the targets at fixed local times. The other

  5. Dipole and quadrupole forces exerted on atoms in laser fields: The nonperturbative approach

    International Nuclear Information System (INIS)

    Sindelka, Milan; Moiseyev, Nimrod; Cederbaum, Lorenz S.

    2006-01-01

    Manipulation of cold atoms by lasers has so far been studied solely within the framework of the conventional dipole approximation, and the atom-light interaction has been treated using low order perturbation theory. Laser control of atomic motions has been ascribed exclusively to the corresponding light-induced dipole forces. In this work, we present a general theory to derive the potential experienced by an atom in a monochromatic laser field in a context analogous to the Born-Oppenheimer approximation for molecules in the field-free case. The formulation goes beyond the dipole approximation and gives rise to the field-atom coupling potential terms which so far have not been taken into consideration in theoretical or experimental studies. Contrary to conventional approaches, our method is based upon the many electron Floquet theory and remains valid also for high intensity laser fields (i.e., for a strongly nonperturbative atom-light interaction). As an illustration of the developed theory, we investigate the trapping of cold atoms in optical lattices. We find that for some atoms for specific laser parameters, despite the absence of the dipole force, the laser trapping is still possible due to the electric quadrupole forces. Namely, we show that by using realistic laser parameters one can form a quadrupole optical lattice which is sufficiently strong to trap Ca and Na atoms

  6. 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.

  7. GLOBAL AND LOCAL COUPLING COMPENSATION EXPERIMENTS IN RHIC USING AC DIPOLES

    International Nuclear Information System (INIS)

    CALAGA, R.; FRANCHI, A., TOMAS, R.; CERN)

    2006-01-01

    Compensation of transverse coupling during the RHIC energy ramp has been proven to be non-trivial and tedious. The lack of accurate knowledge of the coupling sources has initiated several efforts to develop fast techniques using turn-by-turn BPM data to identify and compensate these sources. This paper aims to summarize the beam experiments performed to measure the coupling, matrix and resonance driving terms with the aid of RHIC ac dipoles at injection energy

  8. 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)

  9. 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.

  10. 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

  11. Broadband electromagnetic dipole scattering by coupled multiple nanospheres

    Science.gov (United States)

    Jing, Xufeng; Ye, Qiufeng; Hong, Zhi; Zhu, Dongshuo; Shi, Guohua

    2017-11-01

    With the development of nanotechnology, the ability to manipulate light at the nanoscale is critical to future optical functional devices. The use of high refractive index dielectric single silicon nanoparticle can achieve electromagnetic dipole resonant properties. Compared with single nanosphere, the use of dimer and trimer introduces an additional dimension (gap size) for improving the performance of dielectric optical devices through the coupling between closely connected silicon nanospheres. When changing the gap size between the nanospheres, the interaction between the particles can be from weak to strong. Compared with single nanospheres, dimerized or trimeric nanospheres exhibit more pronounced broadband scattering properties. In addition, by introducing more complex interaction, the trimericed silicon nanospheres exhibit a more significant increase in bandwidth than expected. In addition, the presence of the substrate will also contribute to the increase in the bandwidth of the nanospheres. The broadband response in dielectric nanostructures can be effectively applied to broadband applications such as dielectric nanoantennas or solar cells.

  12. Electric dipole moments with and beyond flavor invariants

    Science.gov (United States)

    Smith, Christopher; Touati, Selim

    2017-11-01

    In this paper, the flavor structure of quark and lepton electric dipole moments in the SM and beyond is investigated using tools inspired from Minimal Flavor Violation. While Jarlskog-like flavor invariants are adequate for estimating CP-violation from closed fermion loops, non-invariant structures arise from rainbow-like processes. Our goal is to systematically construct these latter flavor structures in the quark and lepton sectors, assuming different mechanisms for generating neutrino masses. Numerically, they are found typically much larger, and not necessarily correlated with, Jarlskog-like invariants. Finally, the formalism is adapted to deal with a third class of flavor structures, sensitive to the flavored U (1) phases, and used to study the impact of the strong CP-violating interaction and the interplay between the neutrino Majorana phases and possible baryon and/or lepton number violating interactions.

  13. Electric dipole moments with and beyond flavor invariants

    Directory of Open Access Journals (Sweden)

    Christopher Smith

    2017-11-01

    Full Text Available In this paper, the flavor structure of quark and lepton electric dipole moments in the SM and beyond is investigated using tools inspired from Minimal Flavor Violation. While Jarlskog-like flavor invariants are adequate for estimating CP-violation from closed fermion loops, non-invariant structures arise from rainbow-like processes. Our goal is to systematically construct these latter flavor structures in the quark and lepton sectors, assuming different mechanisms for generating neutrino masses. Numerically, they are found typically much larger, and not necessarily correlated with, Jarlskog-like invariants. Finally, the formalism is adapted to deal with a third class of flavor structures, sensitive to the flavored U(1 phases, and used to study the impact of the strong CP-violating interaction and the interplay between the neutrino Majorana phases and possible baryon and/or lepton number violating interactions.

  14. 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.

  15. A sensitive search for a muon electric dipole moment

    International Nuclear Information System (INIS)

    Semertzidis, Yannis K.; Carey, R.M.; Miller, J.P.; Rind, O.; Roberts, B.L.; Sulak, L.R.; Brown, H.; Danby, G.T.; Jackson, J.W.; Larsen, R.; Lazarus, D.M.; Meng, W.; Morse, W.M.; Ozben, C.S.; Prigl, R.; Semertzidis, Y.K.; Balakin, V.; Bazhan, A.; Dudnikov, A.; Khazin, B. I.

    2001-01-01

    We are proposing a new method to carry out a dedicated search for a permanent electric dipole moment (EDM) of the muon with a sensitivity at a level of 10 -24 e·cm. The experiment will be sensitive to non-standard physics like SUSY. The experimental design exploits the strong motional electric field sensed by relativistic particles in a magnetic storage ring. As a key feature, a novel technique has been invented in which the g-2 precession is compensated with a radial electric field. The EDM signature will be an out of plane muon spin precession as a function of time. The rate of this precession will be proportional to the EDM amplitude of the muon

  16. 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...

  17. 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

  18. 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.

  19. 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.

  20. 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....

  1. 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.

  2. 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)

  3. 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...

  4. 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.

  5. 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.

  6. 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.

  7. 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...

  8. 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.

  9. 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.

  10. 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.

  11. Magnets for the national spallation neutron source accumulator ring

    International Nuclear Information System (INIS)

    Tuozzolo, J.; Brodowski, J.; Danby, G.

    1997-01-01

    The National Spallation Neutron Source Accumulator Ring will require large aperture dipole magnets, strong focusing quadrupole magnets, and smaller low field dipole, quadrupole, and sextupole correcting magnets. All of the magnets will provide a fixed magnetic field throughout the accumulator's fill/storage/extraction cycle. Similar fixed field magnets will also be provided for the beam transport systems. Because of the high intensity in the accumulator, the magnets must be designed with high tolerances for optimum field quality and for the high radiation environment which may be present at the injection/extraction areas, near the collimators, and near the target area. Field specifications and field plots are presented as well as planned fabrication methods and procedures, cooling system design, support, and installation

  12. Localization of heart vectors produced by epicardial burns and ectopic stimuli; validation of a dipole ranging method.

    Science.gov (United States)

    Ideker, R E; Bandura, J P; Larsen, R A; Cox, J W; Keller, F W; Brody, D A

    1975-01-01

    Location of the equivalent cardiac dipole has been estimated but not fully verified in several laboratories. To test the accuracy of such a procedure, injury vectors were produced in 14 isolated, perfused rabbit hearts by epicardial searing. Strongly dipolar excitation fronts were produced in 6 additional hearts by left ventricular pacing. Twenty computer-processed signals, derived from surface electrodes on a spherical electrolyte-filled tank containing the test preparation, were optimally fitted with a locatable cardiac dipole that accounted for over 99% of the root-mean-square surface potential. For the 14 burns (mean radius 5.0 mm), the S-T injury dipole was located 3.4 plus or minus 0.7 (SD) mm from the burn center. For the 6 paced hearts, the dipole early in the ectopic beat was located 3.7 mm (range 2.6 to 4.6 mm) from the stimulating electrode. Phase inhomogeneities within the chamber appeared to have a small but predictable effect on dipole site determination. The study demonstrates that equivalent dipole location can be determined with acceptable accuracy from potential measurements of the external cardiac field.

  13. Neutron electric dipole moment in the minimal supersymmetric standard model

    International Nuclear Information System (INIS)

    Inui, T.; Mimura, Y.; Sakai, N.; Sasaki, T.

    1995-01-01

    The neutron electric dipole moment (EDM) due to the single quark EDM and to the transition EDM is calculated in the minimal supersymmetric standard model. Assuming that the Cabibbo-Kobayashi-Maskawa matrix at the grand unification scale is the only source of CP violation, complex phases are induced in the parameters of soft supersymmetry breaking at low energies. The chargino one-loop diagram is found to give the dominant contribution of the order of 10 -27 similar 10 -29 e.cm for the quark EDM, assuming the light chargino mass and the universal scalar mass to be 50 GeV and 100 GeV, respectively. Therefore the neutron EDM in this class of model is difficult to measure experimentally. The gluino one-loop diagram also contributes due to the flavor changing gluino coupling. The transition EDM is found to give dominant contributions for certain parameter regions. (orig.)

  14. Towards a new measurement of the neutron electric dipole moment

    International Nuclear Information System (INIS)

    Ban, G.; Bodek, K.; Daum, M.; Henneck, R.; Heule, S.; Kasprzak, M.; Khomytov, N.; Kirch, K.; Knecht, A.; Kistryn, S.; Knowles, P.; Kuzniak, M.; Lefort, T.; Naviliat-Cuncic, O.; Pichlmaier, A.; Plonka, C.; Quemener, G.; Rebetez, M.; Rebreyend, D.; Rogel, G.

    2006-01-01

    Precision measurements of particle electric dipole moments (EDMs) provide extremely sensitive means to search for non-standard mechanisms of T (or CP) violation. For the neutron EDM, the upper limit has been reduced by eight orders of magnitude in 50 years thereby excluding several CP violation scenarios. We report here on a new effort aiming at improving the neutron EDM limit by two orders of magnitude, down to a level of 3 x 10 -28 e.cm. The two central elements of the approach are the use of the higher densities which will be available at the new dedicated spallation UCN source at the Paul Scherrer Institute, and the optimization of the in-vacuum Ramsey resonance technique, with storage chambers at room temperature, to reach new limits of sensitivity.

  15. The quest for an electric dipole moment of the neutron

    International Nuclear Information System (INIS)

    Schmidt-Wellenburg, P.

    2016-01-01

    To date no electric dipole moment of the neutron (nEDM) has been observed. Why it is so vanishing small, escaping detection in the last 50 years, is not easy to explain. In general it is considered as the most sensitive probe for the violation of the combined symmetry of charge and parity (CP). A discovery could shed light on the poorly understood matter/anti-matter asymmetry of the universe. The neutron might one day help to distinguish different sources of CP-violation in combination with measurements of the electron and diamagnetic EDMs. This proceedings article presents an overview of the most important concepts in searches for an nEDM and presents a brief overview of the world wide efforts.

  16. Electric dipole induced by gravity in fat branes

    Energy Technology Data Exchange (ETDEWEB)

    Dahia, F. [Dep. of Physics, Univ. Fed. da Paraíba, João Pessoa, Paraíba (Brazil); Dep. of Physics, Univ. Fed. de Campina Grande, Campina Grande, Paraíba (Brazil); Albuquerque Silva, Alex de [Dep. of Physics, Univ. Fed. da Paraíba, João Pessoa, Paraíba (Brazil); Dep. of Physics, Univ. Fed. de Campina Grande, Sumé, Paraíba (Brazil); Romero, C. [Dep. of Physics, Univ. Fed. da Paraíba, João Pessoa, Paraíba (Brazil)

    2014-05-01

    In the fat brane model, also known as the split fermion model, it is assumed that leptons and baryons live in different hypersurfaces of a thick brane in order to explain the proton stability without invoking any symmetry. It turns out that, in the presence of a gravity source M, particles will see different four-dimensional (4D) geometries and hence, from the point of view of 4D-observers, the equivalence principle will be violated. As a consequence, we show that a hydrogen atom in the gravitational field of M will acquire a radial electric dipole. This effect is regulated by the Hamiltonian H{sub d}=−μA⋅δr, which is the gravitational analog of the Stark Hamiltonian, where the electric field is replaced by the tidal acceleration A due to the split of fermions in the brane and the atomic reduced mass μ substitutes the electric charge.

  17. The quest for an electric dipole moment of the neutron

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt-Wellenburg, P., E-mail: philipp.schmidt-wellenburg@psi.ch [Paul Scherrer Institute, 5232 Villigen (Switzerland)

    2016-07-07

    To date no electric dipole moment of the neutron (nEDM) has been observed. Why it is so vanishing small, escaping detection in the last 50 years, is not easy to explain. In general it is considered as the most sensitive probe for the violation of the combined symmetry of charge and parity (CP). A discovery could shed light on the poorly understood matter/anti-matter asymmetry of the universe. The neutron might one day help to distinguish different sources of CP-violation in combination with measurements of the electron and diamagnetic EDMs. This proceedings article presents an overview of the most important concepts in searches for an nEDM and presents a brief overview of the world wide efforts.

  18. Electric dipole moments of light nuclei in effective field theory

    Energy Technology Data Exchange (ETDEWEB)

    Bsaisou, Jan; Liebig, Susanna; Minossi, David [Institut fuer Kernphysik, Forschungszentrum Juelich (Germany); Juelich Center for Hadron Physics, Forschungszentrum Juelich (Germany); Hanhart, Christoph; Nogga, Andreas; Vries, Jordy de; Wirzba, Andreas [Institut fuer Kernphysik, Forschungszentrum Juelich (Germany); Juelich Center for Hadron Physics, Forschungszentrum Juelich (Germany); Institute for Advanced Simulation, Forschungszentrum Juelich (Germany); JARA - Forces and Matter Experiments, Forschungszentrum Juelich (Germany); Meissner, UlfG. [Institut fuer Kernphysik, Forschungszentrum Juelich (Germany); Juelich Center for Hadron Physics, Forschungszentrum Juelich (Germany); Institute for Advanced Simulation, Forschungszentrum Juelich (Germany); JARA - Forces and Matter Experiments, Forschungszentrum Juelich (Germany); Helmholtz-Institut fuer Strahlen und Kernphysik, Universitaet Bonn (Germany)

    2014-07-01

    Electric dipole moments (EDMs) break parity (P) and time-reversal (T) symmetry and thus, by the CPT-theorem, CP-symmetry. Once measured, they will be unambiguous signs of new physics since CP-violation from the standard mechanism predicts EDMs that are experimentally inaccessible in the foreseeable future. We calculate within the framework of effective field theory the two-nucleon contributions to the EDMs of the deuteron, helion, and triton induced by P- and T-violating terms that arise from the QCD θ-term or dimension-6 sources of physics beyond the Standard Model (SM). We demonstrate what insights into physics beyond the SM can be gained from a suitable combination of measurements and, if needed, supplementary lattice QCD calculations.

  19. 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.

  20. 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.

  1. Hybrid RPA-cluster model for the dipole strength function of sup(11)Li

    International Nuclear Information System (INIS)

    Teruya, N.; Bertulani, C.A.; Krewald, S.

    1990-09-01

    A hybrid RPA-cluster model is developed and applied to the calculation of the dipole response of sup(11)L1. A strong collective state at 1.81 MeV is found. Its width is predicted to be 4.0 MeV. The electromagnetic excitation cross section was found to be 700 mb for sup(11)L1 + sup(208)Pb (E = 800 MeV/n), close to the experimental result. (author)

  2. 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.

  3. Spin-orbit coupling and electric-dipole spin resonance in a nanowire double quantum dot.

    Science.gov (United States)

    Liu, Zhi-Hai; Li, Rui; Hu, Xuedong; You, J Q

    2018-02-02

    We study the electric-dipole transitions for a single electron in a double quantum dot located in a semiconductor nanowire. Enabled by spin-orbit coupling (SOC), electric-dipole spin resonance (EDSR) for such an electron can be generated via two mechanisms: the SOC-induced intradot pseudospin states mixing and the interdot spin-flipped tunneling. The EDSR frequency and strength are determined by these mechanisms together. For both mechanisms the electric-dipole transition rates are strongly dependent on the external magnetic field. Their competition can be revealed by increasing the magnetic field and/or the interdot distance for the double dot. To clarify whether the strong SOC significantly impact the electron state coherence, we also calculate relaxations from excited levels via phonon emission. We show that spin-flip relaxations can be effectively suppressed by the phonon bottleneck effect even at relatively low magnetic fields because of the very large g-factor of strong SOC materials such as InSb.

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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.

  9. 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)

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. The sound field of a rotating dipole in a plug flow.

    Science.gov (United States)

    Wang, Zhao-Huan; Belyaev, Ivan V; Zhang, Xiao-Zheng; Bi, Chuan-Xing; Faranosov, Georgy A; Dowell, Earl H

    2018-04-01

    An analytical far field solution for a rotating point dipole source in a plug flow is derived. The shear layer of the jet is modelled as an infinitely thin cylindrical vortex sheet and the far field integral is calculated by the stationary phase method. Four numerical tests are performed to validate the derived solution as well as to assess the effects of sound refraction from the shear layer. First, the calculated results using the derived formulations are compared with the known solution for a rotating dipole in a uniform flow to validate the present model in this fundamental test case. After that, the effects of sound refraction for different rotating dipole sources in the plug flow are assessed. Then the refraction effects on different frequency components of the signal at the observer position, as well as the effects of the motion of the source and of the type of source are considered. Finally, the effect of different sound speeds and densities outside and inside the plug flow is investigated. The solution obtained may be of particular interest for propeller and rotor noise measurements in open jet anechoic wind tunnels.

  20. 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.)

  1. 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.

  2. 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.

  3. 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.

  4. Electromagnetic Design Study for a Large Bore 15T Superconducting Dipole Magnet

    CERN Document Server

    Schwerg, N; Devred, Arnaud; Henke, H

    2005-01-01

    In the framework of research and development (R&D) activities at CERN the Next European Dipole (NED) program is one which is to the development of a high-field dipole magnet using Nb_3Sn superconductors. Part of the NED activities is a design study of different possible dipole configurations which is shared amongst the collaborating institutes. This thesis covers the electromagnetic design study of an 88 mm large bore superconducting 15 T dipole magnet with a coil cross section in cos-theta-layer design. Based on analytically describable geometries the sources of multipole errors are studied and elementary estimations of the magnet are carried out, e.g., the required amount of superconductors or the influence of the iron yoke thickness on the field quality. The magnet cross section for NED is optimized by means of the CERN field computation program ROXIE. The preliminary NED design serves as starting point for the coil cross section optimization with respect to field quality and a radial positioning of th...

  5. A novel background field removal method for MRI using projection onto dipole fields (PDF).

    Science.gov (United States)

    Liu, Tian; Khalidov, Ildar; de Rochefort, Ludovic; Spincemaille, Pascal; Liu, Jing; Tsiouris, A John; Wang, Yi

    2011-11-01

    For optimal image quality in susceptibility-weighted imaging and accurate quantification of susceptibility, it is necessary to isolate the local field generated by local magnetic sources (such as iron) from the background field that arises from imperfect shimming and variations in magnetic susceptibility of surrounding tissues (including air). Previous background removal techniques have limited effectiveness depending on the accuracy of model assumptions or information input. In this article, we report an observation that the magnetic field for a dipole outside a given region of interest (ROI) is approximately orthogonal to the magnetic field of a dipole inside the ROI. Accordingly, we propose a nonparametric background field removal technique based on projection onto dipole fields (PDF). In this PDF technique, the background field inside an ROI is decomposed into a field originating from dipoles outside the ROI using the projection theorem in Hilbert space. This novel PDF background removal technique was validated on a numerical simulation and a phantom experiment and was applied in human brain imaging, demonstrating substantial improvement in background field removal compared with the commonly used high-pass filtering method. Copyright © 2011 John Wiley & Sons, Ltd.

  6. Doubly and triply linked porphyrin-perylene monoimides as near IR dyes with large dipole moments and high photostability

    KAUST Repository

    Jiao, Chongjun; Huang, Kuo-Wei; Chi, Chunyan; Wu, Jishan

    2011-01-01

    Doubly and triply linked porphyrin-perylene monoimides 3 and 4, with extraordinary stability, large dipole moments, and strong near IR absorption, were prepared by means of one-pot oxidative cyclodehydrogenation promoted by FeCl 3. © 2010 American

  7. Doubly and triply linked porphyrin-perylene monoimides as near IR dyes with large dipole moments and high photostability

    KAUST Repository

    Jiao, Chongjun

    2011-01-21

    Doubly and triply linked porphyrin-perylene monoimides 3 and 4, with extraordinary stability, large dipole moments, and strong near IR absorption, were prepared by means of one-pot oxidative cyclodehydrogenation promoted by FeCl 3. © 2010 American Chemical Society.

  8. 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.

  9. 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

  10. 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

  11. 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).

  12. 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.)

  13. 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)

  14. An alternate end design for SSC dipoles

    International Nuclear Information System (INIS)

    Peters, C.; Caspi, S.; Taylor, C.

    1989-02-01

    Experience in the SSC dipole program has shown that fabrication of cylindrical coil ends is difficult. Cable stiffness requires large forces to maintain the proper position of the conductors in the end during winding. After winding, the coil ends remain distorted nd significant motion of the need conductors is required to force the coil end into the molding cavity. Local mechanical stresses are high during this process and extra pieces of insulation are required to prevent turn-to-turn shorts from developing during the winding and molding steps. Prior to assembly the coil end is compressed in a mold cavity and injected with a filler material to correct surface irregularities and fill voids in the end. LBL has developed an alternate design which permits the conductors to be wound over the end using minimal force and technician coerosion. The conductors are placed on a conical surface where the largest diameter over the outer layer conductors is 10 cm. No coil end spaces or insulation pieces between turns are required. The conductor geometry was analytically optimized to meet SSC multipole requirements for the ends. The first 1-m dipole utilizing this end geometry has been constructed and successfully tested. Design and construction data are presented. Also model test results, including training and multipole measurements of the end are given. 1 ref., 12 figs., 3 tabs

  15. Mean-field energy-level shifts and dielectric properties of strongly polarized Rydberg gases

    OpenAIRE

    Zhelyazkova, V.; Jirschik, R.; Hogan, S. D.

    2016-01-01

    Mean-field energy-level shifts arising as a result of strong electrostatic dipole interactions within dilute gases of polarized helium Rydberg atoms have been probed by microwave spectroscopy. The Rydberg states studied had principal quantum numbers n=70 and 72, and electric dipole moments of up to 14 050 D, and were prepared in pulsed supersonic beams at particle number densities on the order of 108 cm−3. Comparisons of the experimental data with the results of Monte Carlo calculations highl...

  16. DIPOLE COLLAPSE AND DYNAMO WAVES IN GLOBAL DIRECT NUMERICAL SIMULATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Schrinner, Martin; Dormy, Emmanuel [MAG (ENS/IPGP), LRA, Ecole Normale Superieure, 24 Rue Lhomond, 75252 Paris Cedex 05 (France); Petitdemange, Ludovic, E-mail: martin@schrinner.eu [Previously at Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, 69117 Heidelberg, Germany. (Germany)

    2012-06-20

    Magnetic fields of low-mass stars and planets are thought to originate from self-excited dynamo action in their convective interiors. Observations reveal a variety of field topologies ranging from large-scale, axial dipoles to more structured magnetic fields. In this article, we investigate more than 70 three-dimensional, self-consistent dynamo models in the Boussinesq approximation obtained by direct numerical simulations. The control parameters, the aspect ratio, and the mechanical boundary conditions have been varied to build up this sample of models. Both strongly dipolar and multipolar models have been obtained. We show that these dynamo regimes in general can be distinguished by the ratio of a typical convective length scale to the Rossby radius. Models with a predominantly dipolar magnetic field were obtained, if the convective length scale is at least an order of magnitude larger than the Rossby radius. Moreover, we highlight the role of the strong shear associated with the geostrophic zonal flow for models with stress-free boundary conditions. In this case the above transition disappears and is replaced by a region of bistability for which dipolar and multipolar dynamos coexist. We interpret our results in terms of dynamo eigenmodes using the so-called test-field method. We can thus show that models in the dipolar regime are characterized by an isolated 'single mode'. Competing overtones become significant as the boundary to multipolar dynamos is approached. We discuss how these findings relate to previous models and to observations.

  17. High uniformity magnetic coil for search of neutron electric dipole moment

    Energy Technology Data Exchange (ETDEWEB)

    Perez Galvan, A., E-mail: apg@caltech.edu [W.K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA, 91125 (United States); Plaster, B. [Department of Physics and Astronomy, University of Kentucky, Lexington, KY, 40506 (United States); Boissevain, J.; Carr, R.; Filippone, B.W.; Mendenhall, M.P.; Schmid, R. [W.K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA, 91125 (United States); Alarcon, R.; Balascuta, S. [Department of Physics, Arizona State University, Tempe, AZ 85287 (United States)

    2011-12-21

    We present in this article a prototype magnetic coil that has been developed for a new search for the electric dipole moment of the neutron at the Spallation Neutron Source at Oak Ridge National Laboratory. The gradients of the magnetic field generated by the coil have been optimized to reduce known systematic effects and to yield long polarization lifetimes of the trapped particles sampling the highly uniform magnetic field. Measurements of the field uniformity of this prototype magnetic coil are also presented.

  18. Neutron electric dipole moment and possibilities of increasing accuracy of experiments

    Energy Technology Data Exchange (ETDEWEB)

    Serebrov, A. P., E-mail: serebrov@pnpi.spb.ru; Kolomenskiy, E. A.; Pirozhkov, A. N.; Krasnoshchekova, I. A.; Vasiliev, A. V.; Polyushkin, A. O.; Lasakov, M. S.; Murashkin, A. N.; Solovey, V. A.; Fomin, A. K.; Shoka, I. V.; Zherebtsov, O. M. [National Research Centre “Kurchatov Institute”, Petersburg Nuclear Physics Institute (Russian Federation); Aleksandrov, E. B.; Dmitriev, S. P.; Dovator, N. A. [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation); Geltenbort, P.; Ivanov, S. N.; Zimmer, O. [Institut Max von Laue–Paul Langevin (France)

    2016-01-15

    The paper reports the results of an experiment on searching for the neutron electric dipole moment (EDM), performed on the ILL reactor (Grenoble, France). The double-chamber magnetic resonance spectrometer (Petersburg Nuclear Physics Institute (PNPI)) with prolonged holding of ultra cold neutrons has been used. Sources of possible systematic errors are analyzed, and their influence on the measurement results is estimated. The ways and prospects of increasing accuracy of the experiment are discussed.

  19. Converting a Monopole Emission into a Dipole Using a Subwavelength Structure

    Science.gov (United States)

    Fan, Xu-Dong; Zhu, Yi-Fan; Liang, Bin; Cheng, Jian-chun; Zhang, Likun

    2018-03-01

    High-efficiency emission of multipoles is unachievable by a source much smaller than the wavelength, preventing compact acoustic devices for generating directional sound beams. Here, we present a primary scheme towards solving this problem by numerically and experimentally enclosing a monopole sound source in a structure with a dimension of around 1 /10 sound wavelength to emit a dipolar field. The radiated sound power is found to be more than twice that of a bare dipole. Our study of efficient emission of directional low-frequency sound from a monopole source in a subwavelength space may have applications such as focused ultrasound for imaging, directional underwater sound beams, miniaturized sonar, etc.

  20. Non-Dipole Features of the Geomagnetic Field May Persist for Millions of Years

    Science.gov (United States)

    Biasi, J.; Kirschvink, J. L.

    2017-12-01

    Here we present paleointensity results from within the South Atlantic Anomaly (SAA), which is a large non-dipole feature of the geomagnetic field. Within the area of the SAA, anomalous declinations, inclinations, and intensities are observed. Our results suggest that the SAA has been present for at least 5 Ma. This is orders-of-magnitude greater than any previous estimate, and suggests that some non-dipole features do not `average out' over geologic time, which is a fundamental assumption in all paleodirectional studies. The SAA has been steadily growing in size since the first magnetic measurements were made in the South Atlantic, and it is widely believed to have appeared 400 years ago. Recent studies from South Africa (Tarduno et al. (2015)) and Tristan da Cunha (Shah et al. (2016)) have suggested that the SAA has persisted for 1 ka and 96 ka respectively. We conducted paleointensity (PI) experiments on basaltic lavas from James Ross Island, on the Antarctic Peninsula. This large shield volcano has been erupting regularly over the last 6+ Ma (dated via Ar/Ar geochronology), and therefore contains the most complete volcanostratigraphic record in the south Atlantic. Our PI experiments used the Thellier-Thellier method, the IZZI protocol, and the same selection criteria as the Lawrence et al. (2009) study of Ross Island lavas (near McMurdo Station), which is the only comparable PI study on the Antarctic continent. We determined an average paleointensity at JRI of 13.8±5.2 μT, which is far lower than what we would expect from a dipole field (55 μT). In addition, this is far lower than the current value over James Ross Island of 36 μT. These results support the following conclusions: The time-averaged field model of Juarez et al. (1998) and Tauxe et al. (2013) is strongly favored by our PI data. The SAA has persisted over James Ross Island for at least 5 Ma, and has not drifted significantly over that time. The strength of non-dipole features such as the SAA

  1. Coherent Vortex Simulation (CVS) of vortex-dipoles impinging on a no-slip wall

    Science.gov (United States)

    Schneider, Kai; Farge, Marie

    2004-11-01

    Recently, we have introduced a new wavelet-based method, called Coherent Vortex Simulation (CVS), to compute turbulent flows (Flow, Turbulence and Combustion 66(4), 2001). The main idea is to split the flow into two orthogonal parts, a coherent flow and an incoherent background flow, using a nonlinear wavelet filtering of vorticity (Phys. Fluids, 11(8), 1999). As the coherent flow is responsible for the nonlinear dynamics, its evolution is deterministically computed in an adaptive wavelet basis, while the incoherent background flow being noise-like, structureless and decorrelated, its influence on the coherent flow is statistically modelled. Since the coherent part is described by only few wavelets, it is possible to reduce the computational cost, both in terms of memory requirement and cpu time. In order to take into account no-slip boundary conditions, we coupled the adaptive wavelet solver with a volume penalization technique (ACHA, 12, 2002). Here, we present applications of the CVS method to compute vortex dipoles impinging on a no-slip wall in a square container at different Reynolds numbers, which is a challenging test case for numerical methods. We observe the creation of strong vorticity gradients and the production of enstrophy when the dipole hits the wall. We show that the computational grid is dynamically adapted to the dipole evolution, since the wavelet nonlinear filter automatically refines the grid in regions of strong gradients. Note that during the computation only 5% out of 1024^2 wavelet coefficients are thus used.

  2. Structure of the pygmy dipole resonance in Sn-124

    NARCIS (Netherlands)

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

    2012-01-01

    Background: In atomic nuclei, a concentration of electric dipole strength around the particle threshold, commonly denoted as pygmy dipole resonance, may have a significant impact on nuclear structure properties and astrophysical scenarios. A clear identification of these states and the structure of

  3. Methods for production of UNK SC-dipoles magnetic measurements

    International Nuclear Information System (INIS)

    Smirnov, N.L.

    1991-01-01

    Many SC-dipoles for UNK will require from the chosen magnetic measurement methods high accuracy and efficiency. The brief of using methods, their possibilities and analysis of their errors are given. The measurements results for a full-scale model of SC-dipole SPDM1 are presented. 5 refs.; 4 figs.; 4 tabs

  4. Diagnostics of the Fermilab Tevatron using an AC dipole

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, Ryoichi [Univ. of Texas, Austin, TX (United States)

    2008-08-01

    The Fermilab Tevatron is currently the world's highest energy colliding beam facility. Its counter-rotating proton and antiproton beams collide at 2 TeV center-of-mass. Delivery of such intense beam fluxes to experiments has required improved knowledge of the Tevatron's beam optical lattice. An oscillating dipole magnet, referred to as an AC dipole, is one of such a tool to non-destructively assess the optical properties of the synchrotron. We discusses development of an AC dipole system for the Tevatron, a fast-oscillating (f ~ 20 kHz) dipole magnet which can be adiabatically turned on and off to establish sustained coherent oscillations of the beam particles without affecting the transverse emittance. By utilizing an existing magnet and a higher power audio amplifier, the cost of the Tevatron AC dipole system became relatively inexpensive. We discuss corrections which must be applied to the driven oscillation measurements to obtain the proper interpretation of beam optical parameters from AC dipole studies. After successful operations of the Tevatron AC dipole system, AC dipole systems, similar to that in the Tevatron, will be build for the CERN LHC. We present several measurements of linear optical parameters (beta function and phase advance) for the Tevatron, as well as studies of non-linear perturbations from sextupole and octupole elements.

  5. The status of the electric dipole moment of the neutron

    International Nuclear Information System (INIS)

    Grimus, W.

    1990-01-01

    The electric dipole moment of particles in quantum mechanics and quantum field theory is discussed. Furthermore, calculations of the neutron electric dipole moment in the standard model and several of its low-energy extensions are reviewed. 47 refs., 7 figs. (Author)

  6. Electric dipole moments of elementary particles, nuclei, atoms, and molecules

    International Nuclear Information System (INIS)

    Commins, Eugene D.

    2007-01-01

    The significance of particle and nuclear electric dipole moments is explained in the broader context of elementary particle physics and the charge-parity (CP) violation problem. The present status and future prospects of various experimental searches for electric dipole moments are surveyed. (author)

  7. Electric dipole moment of the electron and of the neutron

    Science.gov (United States)

    Barr, S. M.; Zee, A.

    1990-01-01

    It is shown that if Higgs-boson exchange mediates CP violation a significant electric dipole moment for the electron can result. Analogous effects can contribute to the neutron's electric dipole moment at a level competitive with Weinberg's three-gluon operator.

  8. Communication: Permanent dipoles contribute to electric polarization in chiral NMR spectra

    International Nuclear Information System (INIS)

    Buckingham, A. David

    2014-01-01

    Nuclear magnetic resonance spectroscopy is blind to chirality because the spectra of a molecule and its mirror image are identical unless the environment is chiral. However, precessing nuclear magnetic moments in chiral molecules in a strong magnetic field induce an electric polarization through the nuclear magnetic shielding polarizability. This effect is equal and opposite for a molecule and its mirror image but is small and has not yet been observed. It is shown that the permanent electric dipole moment of a chiral molecule is partially oriented through the antisymmetric part of the nuclear magnetic shielding tensor, causing the electric dipole to precess with the nuclear magnetic moment and producing a much larger temperature-dependent electric polarization with better prospects of detection

  9. Strong spin-photon coupling in silicon

    Science.gov (United States)

    Samkharadze, N.; Zheng, G.; Kalhor, N.; Brousse, D.; Sammak, A.; Mendes, U. C.; Blais, A.; Scappucci, G.; Vandersypen, L. M. K.

    2018-03-01

    Long coherence times of single spins in silicon quantum dots make these systems highly attractive for quantum computation, but how to scale up spin qubit systems remains an open question. As a first step to address this issue, we demonstrate the strong coupling of a single electron spin and a single microwave photon. The electron spin is trapped in a silicon double quantum dot, and the microwave photon is stored in an on-chip high-impedance superconducting resonator. The electric field component of the cavity photon couples directly to the charge dipole of the electron in the double dot, and indirectly to the electron spin, through a strong local magnetic field gradient from a nearby micromagnet. Our results provide a route to realizing large networks of quantum dot–based spin qubit registers.

  10. Electric dipole moments in the MSSM at large tan β

    International Nuclear Information System (INIS)

    Demir, D.; Olive, K.A.; Pospelov, M.; Ritz, A.

    2003-11-01

    Within the minimal supersymmetric standard model (MSSM), the large tan β regime can lead to important modifications in the pattern of CP-violating sources contributing to low energy electric dipole moments (EDMs). In particular, four-fermion CP-violating interactions induced by Higgs exchange should be accounted for alongside the constituent EDMs of quarks and electrons. To this end, we present a comprehensive analysis of three low energy EDM observables - namely the EDMs of thallium, mercury and the neutron - at large tan β, in terms of one- and two-loop contributions to the constituent EDMs and four-fermion interactions. We concentrate on the constrained MSSM as well as the MSSM with non-universal Higgs masses, and include the CP-violating phases of μ and A. Our results indicate that the atomic EDMs receive significant corrections from four-fermion operators, especially when Im(A) is the only CP-violating source, whereas the neutron EDM remains relatively insensitive to these effects. As a consequence, in a large portion of the parameter space, one cannot infer a separate bound on the electron EDM via the experimental constraint on the thallium EDM. Furthermore, we find that the electron EDM can be greatly reduced due to the destructive interference of one- and two-loop contributions with the latter being dominated by virtual staus. (orig.)

  11. Electromagnetic design and development of a combined function horizontal and vertical dipole steerer magnet for medium energy beam transport line

    International Nuclear Information System (INIS)

    Singh, Kumud; Itteera, Janvin; Ukarde, Priti; Teotia, Vikas; Kumar, Prashant; Malhotra, Sanjay; Taly, Y.K.

    2013-01-01

    Medium Energy Beam Transport (MEBT) line is required to match the optical functions between the RFQ and SRF cavities/DTL cavities.The primary function of the MEBT lines is to keep the emittance growth of the output beam as low as possible in a highly space charge environment at low energies. The transverse focusing of the beam is achieved by strong focusing quadrupoles and the longitudinal dynamics is achieved by the buncher cavities. The Dipole Steerers serve the function of a control element to achieve the desired transverse beam position. To minimize the emittance growth high magnetic field rigidity is required in a highly constrained longitudinal space for these corrector magnets. The design and development of an air-cooled dipole steerer magnet has been done for an integral dipole field of 2.1mT-m in a Good Field Region (GFR) of 23 mm diameter with Integral Field homogeneity better than 0.5%. Electromagnetic field simulations were done using 3D-FEM simulation software OPERA. Error sensitivity studies have been carried out to specify the manufacturing tolerances to estimate and minimize the beam transmission loss due to likely misalignments and rotation of the magnet. A combined function dipole corrector magnet has been designed and fabricated at the Control Instrumentation Division, BARC. This paper discusses measurement results of a combined function dipole steerer for MEBT line for Proton (H + ) beam at 2.5 MeV. (author)

  12. Dipoles for High-Energy LHC

    CERN Document Server

    Todesco, E; De Rijk, G; Rossi, L

    2014-01-01

    For the High Energy LHC, a study of a 33 TeV center of mass collider in the LHC tunnel, main dipoles of 20 T operational field are needed. In this paper we first review the conceptual design based on block coil proposed in the Malta workshop, addressing the issues related to coil fabrication and assembly. We then propose successive simplifications of this design, associating a cost estimate of the conductor. We then analyse a block layout for a 15 T magnet. Finally, we consider two layouts based on the D20 and HD2 short models built by LBL. A first analysis of the aspects related to protection of these challenging magnets is given.

  13. Concentric Titled Double-Helix Dipole Magnets

    International Nuclear Information System (INIS)

    Rainer Meinke, Ph.D; Carl Goodzeit; Millicent Ball, Ph.D

    2003-01-01

    The high magnetic fields required for future accelerator magnets can only be achieved with Nb3Sn, other A15 or HTS type conductors, which are brittle and sensitive to mechanical strain. The traditional ''cosine-theta'' dipole configuration has intrinsic drawbacks that make it difficult and expensive to employ such conductors in these designs. Some of these problems involve (1) difficulty in applying enough pre-stress to counteract Lorentz forces without compromising conductor performance; (2) small minimum bend radii of the conductor necessitating the intricate wind-and-react coil fabrication; (3) complex spacers in particular for coil ends and expensive tooling for coil fabrication; (4) typically only 2/3 of the coil aperture can be used with achievable field uniformity

  14. Quench propagation in the SSC dipole magnets

    International Nuclear Information System (INIS)

    Lopez, G.; Snitchler, G.

    1990-09-01

    The effects of quench propagation are modeled in 40mm and 50mm diameter collider dipole magnet designs. A comparative study of the cold diode (passive) and quench heater (active) protection schemes will be presented. The SSCQ modeling program accurately simulates the axial quench velocity and uses phenomenological time delays for turn-to-turn transverse propagation. The axial quench velocity is field dependent and consequently, each conductor's quench profile is tracked separately. No symmetry constraints are employed and the distribution of the temperatures along the conductor differs from the adiabatic approximation. A single magnet has a wide margin of self protection which suggests that passive protection schemes must be considered. 6 refs., 3 figs., 1 tab

  15. Vacuum electron acceleration by coherent dipole radiation

    International Nuclear Information System (INIS)

    Troha, A.L.; Van Meter, J.R.; Landahl, E.C.; Alvis, R.M.; Hartemann, F.V.; Troha, A.L.; Van Meter, J.R.; Landahl, E.C.; Alvis, R.M.; Li, K.; Luhmann, N.C. Jr.; Hartemann, F.V.; Unterberg, Z.A.; Kerman, A.K.

    1999-01-01

    The validity of the concept of laser-driven vacuum acceleration has been questioned, based on an extrapolation of the well-known Lawson-Woodward theorem, which stipulates that plane electromagnetic waves cannot accelerate charged particles in vacuum. To formally demonstrate that electrons can indeed be accelerated in vacuum by focusing or diffracting electromagnetic waves, the interaction between a point charge and coherent dipole radiation is studied in detail. The corresponding four-potential exactly satisfies both Maxwell's equations and the Lorentz gauge condition everywhere, and is analytically tractable. It is found that in the far-field region, where the field distribution closely approximates that of a plane wave, we recover the Lawson-Woodward result, while net acceleration is obtained in the near-field region. The scaling of the energy gain with wave-front curvature and wave amplitude is studied systematically. copyright 1999 The American Physical Society

  16. Isabelle dipole and quadrupole coil configurations

    International Nuclear Information System (INIS)

    Dahl, P.F.; Hahn, H.

    1980-01-01

    The coil configurations of the ISABELLE dipole and quadrupole magnets have been reviewed and a number of improvements were suggested for incorporation into the final design. The coil designs are basically single layer multiple block approximations to cosine current distributions, wound from a high aspect ratio non-keystoned braided conductor. The blocks are separated by knife-edge wedges to maximize the quench propagation velocity. The current density variation is obtained by an appropriate distribution of the spacer turns and, to a lesser degree, by the wedge locations. The use of inert turns is necessary to minimize the peak field enhancement both in the ends and in the two dimensional section. Schemes for deriving turns distributions yielding harmonic coefficients satisfying the stringent ISABELLE tolerances on field uniformity, while allowing for simplicity in winding and taking into account quench propagation considerations, will be discussed, as well as our approach to the coil end configuration

  17. Field measurement of dipole magnets for TARN

    International Nuclear Information System (INIS)

    Hori, T.; Noda, A.; Hattori, T.; Fujino, T.; Yoshizawa, M.

    1980-05-01

    Eight dipole magnets of window-frame type with zero field gradient have been fabricated for TARN. Various characteristics of the field were examined by a measuring system with a Hall and an NMR probes. The accuracy of the measurement was better than 1 x 10 -4 at the maximum field strength of --9 kG, and the uniformity of the field in the radial direction was better than +-2 x 10 -4 over the whole useful aperture. The deviations both of the field strengths and of the effective lengths among the eight magnets are smaller than +-2 x 10 -3 . The sextupole component of the field and the variation of the effective length over the beam orbits contribute to chromaticities of the ring as the amount of -1.59 and 0.93 in the horizontal and vertical directions, respectively. (author)

  18. Exotic fermions and electric dipole moments

    International Nuclear Information System (INIS)

    Joshipura, A.S.

    1991-01-01

    The contributions of mirror fermions to the electric dipole moments (EDM's) of leptons and neutrons are studied using the available limits on the mixing of the relevant fermions to their mirror partners. These limits imply EDM's several orders of magnitude larger than the current experimental bounds in the case of the electron and the neutron if the relevant CP-violating phases are not unnaturally small. If these phases are large, then the bounds on the EDM's can be used to improve upon the limits on mixing between the ordinary (f) and the mirror (F) fermions. In the specific case of the latter mixing angle being given by (m f /M F ) 1/2 , one can obtain the electron and the neutron EDM's close to experimental bounds

  19. Magnetic field decay in model SSC dipoles

    International Nuclear Information System (INIS)

    Gilbert, W.S.; Althaus, R.F.; Barale, P.J.; Benjegerdes, R.W.; Green, M.A.; Green, M.I.; Scanlan, R.M.

    1988-08-01

    We have observed that some of our model SSC dipoles have long time constant decays of the magnetic field harmonics with amplitudes large enough to result in significant beam loss, if they are not corrected. The magnets were run at constant current at the SSC injection field level of 0.3 tesla for one to three hours and changes in the magnetic field were observed. One explanation for the observed field decay is time dependent superconductor magnetization. Another explanation involves flux creep or flux flow. Data are presented on how the decay changes with previous flux history. Similar magnets with different Nb-Ti filament spacings and matrix materials have different long time field decay. A theoretical model using proximity coupling and flux creep for the observed field decay is discussed. 10 refs., 5 figs., 2 tabs

  20. Dipole-sheet multipole magnets for accelerators

    International Nuclear Information System (INIS)

    Walstrom, P.L.

    1993-01-01

    The dipole-sheet formalism can be used to describe both cylindrical current-sheet multipole magnets and cylindrical-bore magnets made up of permanent magnet blocks. For current sheets, the formalism provides a natural way of finding a finite set of turns that approximate a continuous distribution. The formalism is especially useful In accelerator applications where large-bore, short, high-field-quality magnets that are dominated by fringe fields are needed. A further advantage of the approach is that in systems with either open or cylindrically symmetric magnetic boundaries, analytical expressions for the three-dimensional fields that are suitable for rapid numerical evaluation can be derived. This development is described in some detail. Also, recent developments in higher-order particle-beam optics codes based on the formalism are described briefly

  1. Ac loss measurement of SSC dipole magnets

    International Nuclear Information System (INIS)

    Delchamps, S.; Hanft, R.; Jaffery, T.; Kinney, W.; Koska, W.; Lamm, M.J.; Mazur, P.O.; Orris, D.; Ozelis, J.P.; Strait, J.; Wake, M.

    1992-09-01

    AC losses in full length and 1.5 m model SSC collider dipoles were successfully measured by the direct observation of energy flow into and out of magnets during a ramp cycle. The measurement was performed by using two double-integrating type digital volt meters (DVM's) for current and voltage measurement. Measurements were performed for six is m long ASST magnets and five 1.5 m long model magnets, inducting one 40 mm diameter magnet. There were large variations in the eddy current losses. Since these magnets use conductors with slight deviations in their internal structures and processing of the copper surface depending on the manufacturer, it is likely that there are differences in the contact resistance between strands. Correlation between the ramp rate dependence of the,quench current and the eddy current loss was evident

  2. Effects of dipole magnet inhomogeneities on the beam ellipsoid

    International Nuclear Information System (INIS)

    Tsoupas, N.; Colman, J.; Levine, M.; McKenzie-Wilson, R.; Ward, T.; Grand, P.

    1986-01-01

    The RAYTRACE computer code has been modified to accept magnetic fields measured in the median plane of a dipole magnet. This modification allows one to study the effects of a non-ideal dipole magnet on the beam ellipsoid (as defined by the TRANSPORT code manual). The effects on the beam ellipsoid are due to: field inhomogeneities in the interior region of the dipole, and discrepancies from design conditions of the magnetic field values in the fringe field region. The results of the RAYTRACE code calculations based on experimentally measured fields will be compared with the results derived using both an ideal (no inhomogeneities) dipole with SCOFF boundaries and an ideal dipole with perfect (according to design) fringe fields

  3. 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.)

  4. The dipole moments of the linear polycarbon monosulfides

    International Nuclear Information System (INIS)

    Murakami, Akinori

    1989-01-01

    The dipole moments of the linear polycarbon monosulfides, CS, C 2 S and C 3 S molecule (radical)s were calculated by ab initio SCF-CI method. The equilibrium geometries of the C n S molecules were obtained by MP3 method using the 6-31G** basis set. From the split balencetype (MIDI-4) to the Huzinaga's well tempered extended type(WT) were used to evaluate dipole moments. Final results were obtained using the WT+2d basis set and CI calculation. The calculated dipole moment of the CS molecule, 1.96 debye, is in good agreement with experimental one. The dipole moment of the C 2 S radical is calculated to be 2.81 debye and 3.66 debye for C 3 S molecule. The calculated dipole moments of the C n S will be accurate with in 0.1 debye(5%)

  5. Systematics of the electric dipole response in stable tin isotopes

    Science.gov (United States)

    Bassauer, Sergej; von Neumann-Cosel, Peter; Tamii, Atsushi

    2018-05-01

    The electric dipole is an important property of heavy nuclei. Precise information on the electric dipole response provides information on the electric dipole polarisability which in turn allows to extract important constraints on neutron-skin thickness in heavy nuclei and parameters of the symmetry energy. The tin isotope chain is particularly suited for a systematic study of the dependence of the electric dipole response on neutron excess as it provides a wide mass range of accessible isotopes with little change of the underlying structure. Recently an inelastic proton scattering experiment under forward angles including 0º on 112,116,124Sn was performed at the Research Centre for Nuclear Physics (RCNP), Japan with a focus on the low-energy dipole strength and the polarisability. First results are presented here. Using data from an earlier proton scattering experiment on 120Sn the gamma strength function and level density are determined for this nucleus.

  6. Systematics of the electric dipole response in stable tin isotopes

    Directory of Open Access Journals (Sweden)

    Bassauer Sergej

    2018-01-01

    Full Text Available The electric dipole is an important property of heavy nuclei. Precise information on the electric dipole response provides information on the electric dipole polarisability which in turn allows to extract important constraints on neutron-skin thickness in heavy nuclei and parameters of the symmetry energy. The tin isotope chain is particularly suited for a systematic study of the dependence of the electric dipole response on neutron excess as it provides a wide mass range of accessible isotopes with little change of the underlying structure. Recently an inelastic proton scattering experiment under forward angles including 0º on 112,116,124Sn was performed at the Research Centre for Nuclear Physics (RCNP, Japan with a focus on the low-energy dipole strength and the polarisability. First results are presented here. Using data from an earlier proton scattering experiment on 120Sn the gamma strength function and level density are determined for this nucleus.

  7. Quantum transfer energy in the framework of time-dependent dipole-dipole interaction

    Science.gov (United States)

    El-Shishtawy, Reda M.; Haddon, Robert C.; Al-Heniti, Saleh H.; Raffah, Bahaaudin M.; Berrada, K.; Abdel-Khalek, S.; Al-Hadeethi, Yas F.

    2018-03-01

    In this work, we examine the process of the quantum transfer of energy considering time-dependent dipole-dipole interaction in a dimer system characterized by two-level atom systems. By taking into account the effect of the acceleration and speed of the atoms in the dimer coupling, we demonstrate that the improvement of the probability for a single-excitation transfer energy extremely benefits from the incorporation of atomic motion effectiveness and the energy detuning. We explore the relevance between the population and entanglement during the time-evolution and show that this kind of nonlocal correlation may be generated during the process of the transfer of energy. Our work may provide optimal conditions to implement realistic experimental scenario in the transfer of the quantum energy.

  8. Applicability of the dipole-dipole method for structural studies: examples from the Northern Apennines

    Directory of Open Access Journals (Sweden)

    L. Alfano

    1998-06-01

    Full Text Available We present some results of a geoelectrical investigation program conducted in the Northern Apennines, namely in the Val d'Aveto and Bobbio window and surrounding areas. Field activity included the execution of more than 50 vertical electrical soundings with continuous polar dipole-dipole spread. We image the geometries of some deep geological structures; in particular we found a resistive background, whose resistivity is different along the geoelectrical profiles. In our interpretation the resistive background consists of subligurid and tuscan units underlying the alloctone Ligurid units in the area surrounding the Val d'Aveto and Bobbio window. The resistive background was not found, at least at the same depths, toward north-east. Therefore, the geoelectrical survey revealed the position of the front of the subligurid and Tuscan nappes toward the plain for a depth of about one kilometer.

  9. 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.

  10. Effect of intermolecular dipole-dipole interactions on interfacial supramolecular structures of C3-symmetric hexa-peri-hexabenzocoronene derivatives.

    Science.gov (United States)

    Mu, Zhongcheng; Shao, Qi; Ye, Jun; Zeng, Zebing; Zhao, Yang; Hng, Huey Hoon; Boey, Freddy Yin Chiang; Wu, Jishan; Chen, Xiaodong

    2011-02-15

    Two-dimensional (2D) supramolecular assemblies of a series of novel C(3)-symmetric hexa-peri-hexabenzocoronene (HBC) derivatives bearing different substituents adsorbed on highly oriented pyrolytic graphite were studied by using scanning tunneling microscopy at a solid-liquid interface. It was found that the intermolecular dipole-dipole interactions play a critical role in controlling the interfacial supramolecular assembly of these C(3)-symmetric HBC derivatives at the solid-liquid interface. The HBC molecule bearing three -CF(3) groups could form 2D honeycomb structures because of antiparallel dipole-dipole interactions, whereas HBC molecules bearing three -CN or -NO(2) groups could form hexagonal superstructures because of a special trimeric arrangement induced by dipole-dipole interactions and weak hydrogen bonding interactions ([C-H···NC-] or [C-H···O(2)N-]). Molecular mechanics and dynamics simulations were performed to reveal the physics behind the 2D structures as well as detailed functional group interactions. This work provides an example of how intermolecular dipole-dipole interactions could enable fine control over the self-assembly of disklike π-conjugated molecules.

  11. 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.

  12. ACCELERATION OF POLARIZED BEAMS USING MULTIPLE STRONG PARTIAL SIBERIAN SNAKES

    International Nuclear Information System (INIS)

    ROSER, T.; AHRENS, L.; BAI, M.

    2004-01-01

    Acceleration of polarized protons in the energy range of 5 to 25 GeV is particularly difficult since depolarizing spin resonances are strong enough to cause significant depolarization but full Siberian snakes cause intolerably large orbit excursions. Using a 20-30% partial Siberian snake both imperfection and intrinsic resonances can be overcome. Such a strong partial Siberian snake was designed for the Brookhaven AGS using a dual pitch helical superconducting dipole. Multiple strong partial snakes are also discussed for spin matching at beam injection and extraction

  13. Low-lying dipole strength in the well-deformed nucleus {sup 156}Gd

    Energy Technology Data Exchange (ETDEWEB)

    Tamkas, M. [ExtreMe Matter Institute (EMMI), GSI, Darmstadt (Germany); Graduate School of Natural and Applied Sciences, Yildiz Technical University, Istanbul (Turkey); Isaak, J.; Silva, J. [ExtreMe Matter Institute (EMMI), GSI, Darmstadt (Germany); Frankfurt Institute for Advanced Studies (FIAS), Frankfurt (Germany); Savran, D. [ExtreMe Matter Institute (EMMI), GSI, Darmstadt (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Loeher, B. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Aciksoz, E. [Department of Physics, Akdeniz University (Turkey); Beck, T.; Beller, J.; Gayer, U.; Pietralla, N.; Romig, C.; Werner, V.; Zweidinger, M. [Institut fuer Kernphysik, Technische Universitaet, Darmstadt (Germany); Tornow, W.; Weller, H. [Department of Physics, Duke University, TUNL, Durham (United States); Zilges, A. [Institut fuer Kernphysik, Universitaet zu Koeln (Germany)

    2016-07-01

    In this study the dipole strength has been investigated in the well-deformed nucleus {sup 156}Gd using the method of Nuclear Resonance Fluorescence (NRF). The NRF experiment was performed at the High Intensity vector γ-ray Source at Duke University in combination with the γ{sup 3} setup using a mono-energetic and linearly polarised beam. The dipole strength of {sup 156}Gd has been studied with photon beam energies between 3 MeV and 6.2 MeV. The parity quantum numbers of J=1 states have been determined for the energy region above ∝3 MeV for the first time. Recent results of the {sup 156}Gd(vector γ,γ') experiment are presented and discussed.

  14. Effective field theory, electric dipole moments and electroweak baryogenesis

    International Nuclear Information System (INIS)

    Balazs, Csaba; White, Graham; Yue, Jason

    2017-01-01

    Negative searches for permanent electric dipole moments (EDMs) heavily constrain models of baryogenesis utilising various higher dimensional charge and parity violating (CPV) operators. Using effective field theory, we create a model independent connection between these EDM constraints and the baryon asymmetry of the universe (BAU) produced during a strongly first order electroweak phase transition. The thermal aspects of the high scale physics driving the phase transition are paramaterised by the usual kink solution for the bubble wall profile. We find that operators involving derivatives of the Higgs field yield CPV contributions to the BAU containing derivatives of the Higgs vacuum expectation value (vev), while non-derivative operators lack such contributions. Consequently, derivative operators cannot be eliminated in terms of non-derivative operators (via the equations of motion) if one is agnostic to the new physics that leads to the phase transition. Thus, we re-classify the independent dimension six operators, restricting ourselves to third generation quarks, gauge bosons and the Higgs. Finally, we calculate the BAU (as a function of the bubble wall width and the cutoff) for a derivative and a non-derivative operator, and relate it to the EDM constraints.

  15. 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.

  16. Direct detection of light anapole and magnetic dipole DM

    International Nuclear Information System (INIS)

    Nobile, Eugenio Del; Gelmini, Graciela B.; Huh, Ji-Haeng; Gondolo, Paolo

    2014-01-01

    We present comparisons of direct detection data for ''light WIMPs'' with an anapole moment interaction (ADM) and a magnetic dipole moment interaction (MDM), both assuming the Standard Halo Model (SHM) for the dark halo of our galaxy and in a halo-independent manner. In the SHM analysis we find that a combination of the 90% CL LUX and CDMSlite limits or the new 90% CL SuperCDMS limit by itself exclude the parameter space regions allowed by DAMA, CoGeNT and CDMS-II-Si data for both ADM and MDM. In our halo-independent analysis the new LUX bound excludes the same potential signal regions as the previous XENON100 bound. Much of the remaining signal regions is now excluded by SuperCDMS, while the CDMSlite limit is much above them. The situation is of strong tension between the positive and negative search results both for ADM and MDM. We also clarify the confusion in the literature about the ADM scattering cross section

  17. 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

  18. The electric dipole moment of the neutron a cosmic seismometer?

    CERN Document Server

    Nanopoulos, Dimitri V

    1981-01-01

    One of the most striking successes of Grand Unified Theories is the possibility of understanding, qualitatively and quantitatively the observed baryon asymmetry in the Universe GUTS contain all the basic ingredients for creating the baryon asymmetry, and the expanding Universe provides for free an excellent way to get out of equilibrium at the appropriate times. A very interesting question which is often asked is whether there is some connection between the observed low energy CP-violation in the K-system and the CP-violation operating at superhigh energies and thus responsible for the observed baryon asymmetry. The usual answer is no! Recently, J. Ellis, M.K. Gillard, S.Rudez and the author (Phys. Lett. B, vol.99, p.101, 1981) have done some work towards a connection that may exist between the magnitude of the (still unobserved) electric dipole moment of the neutron (d/sub n /) and the magnitude of the observed baryon asymmetry (n/sub B//n/sub gamma /). This is a review of that work, but with strong emphasis...

  19. Effective field theory, electric dipole moments and electroweak baryogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Balazs, Csaba; White, Graham [ARC Centre of Excellence for Particle Physics at the Terascale School of Physics and Astronomy,Monash University,Victoria 3800 (Australia); Yue, Jason [Department of Physics, National Taiwan Normal University,Taipei 116, Taiwan (China); ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics,The University of Sydney,NSW 2006 (Australia)

    2017-03-07

    Negative searches for permanent electric dipole moments (EDMs) heavily constrain models of baryogenesis utilising various higher dimensional charge and parity violating (CPV) operators. Using effective field theory, we create a model independent connection between these EDM constraints and the baryon asymmetry of the universe (BAU) produced during a strongly first order electroweak phase transition. The thermal aspects of the high scale physics driving the phase transition are paramaterised by the usual kink solution for the bubble wall profile. We find that operators involving derivatives of the Higgs field yield CPV contributions to the BAU containing derivatives of the Higgs vacuum expectation value (vev), while non-derivative operators lack such contributions. Consequently, derivative operators cannot be eliminated in terms of non-derivative operators (via the equations of motion) if one is agnostic to the new physics that leads to the phase transition. Thus, we re-classify the independent dimension six operators, restricting ourselves to third generation quarks, gauge bosons and the Higgs. Finally, we calculate the BAU (as a function of the bubble wall width and the cutoff) for a derivative and a non-derivative operator, and relate it to the EDM constraints.

  20. Oceanic Precondition and Evolution of the Indian Ocean Dipole Events

    Science.gov (United States)

    Horii, T.; Masumoto, Y.; Ueki, I.; Hase, H.; Mizuno, K.

    2008-12-01

    Indian Ocean Dipole (IOD) is one of the interannual climate variability in the Indian Ocean, associated with the negative (positive) SST anomaly in the eastern (western) equatorial region developing during boreal summer/autumn seasons. Japan Agency for Marine-Earth Science and Technology (JAMSTEC) has been deploying TRITON buoys in the eastern equatorial Indian Ocean since October 2001. Details of subsurface ocean conditions associated with IOD events were observed by the mooring buoys in the eastern equatorial Indian Ocean in 2006, 2007, and 2008. In the 2006 IOD event, large-scale sea surface signals in the tropical Indian Ocean associated with the positive IOD started in August 2006, and the anomalous conditions continued until December 2006. Data from the mooring buoys, however, captured the first appearance of the negative temperature anomaly at the thermocline depth with strong westward current anomalies in May 2006, about three months earlier than the development of the surface signatures. Similar appearance of negative temperature anomalies in the subsurface were also observed in 2007 and 2008, while the amplitude, the timing, and the relation to the surface layer were different among the events. The implications of the subsurface conditions for the occurrences of these IOD events are discussed.