International Nuclear Information System (INIS)
Lipkin, H.J.
1983-06-01
The new experimental values of hyperon magnetic moments are compared with sum rules predicted from general quark models. Three difficulties are encountered which are not easily explained by simple models. The isovector contributions of nonstrange quarks to hyperon moments are smaller than the corresponding contribution to nucleon moments, indicating either appreciable configuration mixing present in hyperon wave functions and absent in nucleons or an additional isovector contribution beyond that of valence quarks; e.g. from a pion cloud. The large magnitude of the ω - moment may indicate that the strange quark contribution to the ω moments is considerably larger than the value μ(#betta#) predicted by simple models which have otherwise been very successful. The set of controversial values from different experiments of the μ - moment include a value very close to -(1/2)μ(μ + ) which would indicate that strange quarks do not contribute at all to the μ moments. (author)
International Nuclear Information System (INIS)
Vysotsky, M.I.
1990-03-01
I would like to discuss the problem of a neutrino magnetic moment which is of interest since it deals with the probable time anticorrelation of the solar v flux with the Sun magnetic activity. (author). 19 refs, 2 figs, 1 tab
González-Sprinberg, G. A.; Vidal, J.
2017-10-01
The τ lepton magnetic moment theoretical predictions and measurements are reviewed. While it is believed that such a high mass particle is a good candidate to show up new physics, this is not the case up to now. The magnetic moment of elementary fermions, and in particular the anomalous magnetic moment of the electron, had an historical impact both in relativistic quantum mechanics and in quantum field theories. Besides, many new physics models were discarded when confronted with these magnitudes. More recently, the discrepancy of the experiments and the theoretical predictions for the muon anomalous magnetic moment is still an open issue. For the τ lepton, instead, while the theoretical prediction is well known for the standard model and some new physics models, the data are very far of determining even its sign or the first figure. We will discuss the most important theoretical aspects of the τ magnetic moment, and also the current accepted measurements and future perspectives, in particular related to B-factories.
International Nuclear Information System (INIS)
Towner, I.S.; Khanna, F.C.
1984-01-01
Consideration of core polarization, isobar currents and meson-exchange processes gives a satisfactory understanding of the ground-state magnetic moments in closed-shell-plus (or minus)-one nuclei, A = 3, 15, 17, 39 and 41. Ever since the earliest days of the nuclear shell model the understanding of magnetic moments of nuclear states of supposedly simple configurations, such as doubly closed LS shells +-1 nucleon, has been a challenge for theorists. The experimental moments, which in most cases are known with extraordinary precision, show a small yet significant departure from the single-particle Schmidt values. The departure, however, is difficult to evaluate precisely since, as will be seen, it results from a sensitive cancellation between several competing corrections each of which can be as large as the observed discrepancy. This, then, is the continuing fascination of magnetic moments. In this contribution, we revisit the subjet principally to identify the role played by isobar currents, which are of much concern at this conference. But in so doing we warn quite strongly of the dangers of considering just isobar currents in isolation; equal consideration must be given to competing processes which in this context are the mundane nuclear structure effects, such as core polarization, and the more popular meson-exchange currents
2002-01-01
Experiment IS358 uses the intense and pure beams of copper isotopes provided by the ISOLDE RILIS (resonance ionization laser ion source). The isotopes are implanted and oriented in the low temperature nuclear orientation set-up NICOLE. Magnetic moments are measured by $\\beta$-NMR. Copper (Z=29), with a single proton above the proton-magic nickel isotopes provides an ideal testground for precise shell model calculations of magnetic moments and their experimental verification. In the course of our experiments we already determined the magnetic moments of $^{67}$Ni, $^{67}$Cu, $^{68g}$Cu, $^{69}$Cu and $^{71}$Cu which provide important information on the magicity of the N=40 subshell closure. In 2001 we plan to conclude our systematic investigations by measuring the magnetic moment of the neutron-deficient isotope $^{59}$Cu. This will pave the way for a subsequent study of the magnetic moment of $^{57}$Cu with a complementary method.
International Nuclear Information System (INIS)
Matsuta, K.; Arimura, K.; Nagatomo, T.; Akutsu, K.; Iwakoshi, T.; Kudo, S.; Ogura, M.; Takechi, M.; Tanaka, K.; Sumikama, T.; Minamisono, K.; Miyake, T.; Minamisono, T.; Fukuda, M.; Mihara, M.; Kitagawa, A.; Sasaki, M.; Kanazawa, M.; Torikoshi, M.; Suda, M.; Hirai, M.; Momota, S.; Nojiri, Y.; Sakamoto, A.; Saihara, M.; Ohtsubo, T.; Alonso, J.R.; Krebs, G.F.; Symons, T.J.M.
2004-01-01
The magnetic moment of 33 Cl (Iπ=3/2+, T1/2=2.51s) has been re-measured precisely by β-NMR method. The obtained magnetic moment |μ|=0.7549(3)μN is consistent with the old value 0.7523(16)μN, but is 5 times more accurate. The value is well reproduced by the shell model calculation, μSM=0.70μN. Combined with the magnetic moment of the mirror partner 33 S, the nuclear matrix elements , , , and were derived
Updating neutrino magnetic moment constraints
Directory of Open Access Journals (Sweden)
B.C. Cañas
2016-02-01
Full Text Available In this paper we provide an updated analysis of the neutrino magnetic moments (NMMs, discussing both the constraints on the magnitudes of the three transition moments Λi and the role of the CP violating phases present both in the mixing matrix and in the NMM matrix. The scattering of solar neutrinos off electrons in Borexino provides the most stringent restrictions, due to its robust statistics and the low energies observed, below 1 MeV. Our new limit on the effective neutrino magnetic moment which follows from the most recent Borexino data is 3.1×10−11μB at 90% C.L. This corresponds to the individual transition magnetic moment constraints: |Λ1|≤5.6×10−11μB, |Λ2|≤4.0×10−11μB, and |Λ3|≤3.1×10−11μB (90% C.L., irrespective of any complex phase. Indeed, the incoherent admixture of neutrino mass eigenstates present in the solar flux makes Borexino insensitive to the Majorana phases present in the NMM matrix. For this reason we also provide a global analysis including the case of reactor and accelerator neutrino sources, presenting the resulting constraints for different values of the relevant CP phases. Improved reactor and accelerator neutrino experiments will be needed in order to underpin the full profile of the neutrino electromagnetic properties.
Spontaneous magnetization in high-density quark matter
DEFF Research Database (Denmark)
Tsue, Yasuhiko; da Providência, João; Providência, Constanca
2015-01-01
It is shown that spontaneous magnetization occurs due to the anomalous magnetic moments of quarks in high-density quark matter under the tensor-type four-point interaction. The spin polarized condensate for each flavor of quark appears at high baryon density, which leads to the spontaneous...
Effective magnetic moment of neutrinos in strong magnetic fields
Pérez, A; Masood, S S; Gaitan, R; Rodríguez, S
2002-01-01
In this paper we compute the effective magnetic moment of neutrinos propagating in dense high magnetized medium. Taking typical values of magnetic field and densities of astrophysical objects (such as the cores of supernovae and neutron stars) we obtain an effective type of dipole magnetic moment in agreement with astrophysical and cosmological bounds. (Author)
Macroscopic quantum tunneling of the magnetic moment
Tejada, J.; Hernandez, J. M.; del Barco, E.
1999-05-01
In this paper we review the work done on magnetic relaxation during the last 10 years on both single-domain particles and magnetic molecules and its contribution to the discovery of quantum tunneling of the magnetic moment (Chudnovsky and Tejada, Macroscopic Quantum tunneling of the Magnetic moment, Cambridge University press, Cambridge, 1998). We present first the theoretical expressions and their connection to quantum relaxation and secondly, we show and discuss the experimental results. Finally, we discuss very recent hysteresis data on Mn 12Ac molecules at extremely large sweeping rate for the external magnetic field which suggest the existence of quantum spin—phonon avalanches.
Electrically Controllable Spontaneous Magnetism in Nanoscale Mixed Phase Multiferroics
Energy Technology Data Exchange (ETDEWEB)
He, Q.; Chu, Y. H.; Heron, J. T.; Yang, S. Y.; Wang, C. H.; Kuo, C. Y.; Lin, H. J.; Yu, P.; Liang, C. W.; Zeches, R. J.; Chen, C. T.; Arenholz, E.; Scholl, A.; Ramesh, R.
2010-08-02
The emergence of enhanced spontaneous magnetic moments in self-assembled, epitaxial nanostructures of tetragonal (T-phase) and rhombohedral phases (R-phase) of the multiferroic BiFeO{sub 3} system is demonstrated. X-ray magnetic circular dichroism based photoemission electron microscopy (PEEM) was applied to investigate the local nature of this magnetism. We find that the spontaneous magnetization of the R-phase is significantly enhanced above the canted antiferromagnetic moment in the bulk phase, as a consequence of a piezomagnetic coupling to the adjacent T-phase and the epitaxial constraint. Reversible electric field control and manipulation of this magnetic moment at room temperature is shown using a combination of piezoresponse force microscopy and PEEM studies.
Magnetic moment measurement of magnetic nanoparticles using atomic force microscopy
International Nuclear Information System (INIS)
Park, J-W; Lee, E-C; Ju, H; Yoo, I S; Chang, W-S; Chung, B H; Kim, B S
2008-01-01
Magnetic moment per unit mass of magnetic nanoparticles was found by using the atomic force microscope (AFM). The mass of the nanoparticles was acquired from the resonance frequency shift of the particle-attached AFM probe and magnetic force measurement was also carried out with the AFM. Combining with magnetic field strength, the magnetic moment per unit mass of the nanoparticles was determined as a function of magnetic field strength. (technical design note)
6-quark contribution to nuclear magnetic moments
International Nuclear Information System (INIS)
Ito, H.
1985-01-01
The magnetic moments of nuclei with LS closed shell +/-1 particle are calculated. Core polarization and meson exchange current are treated realistically in order to single out the 6-quark contribution. Overall agreement with experimental values is quite good. It is shown that the 6-quark system contributes to the respective iso-vector and iso-scalar moments with reasonable magnitudes
Baryon magnetic moments: Symmetries and relations
Energy Technology Data Exchange (ETDEWEB)
Parreno, Assumpta [University of Barcelona; Savage, Martin [Univ. of Washington, Seattle, WA (United States); Tiburzi, Brian [City College of New York, NY (United States); City Univ. (CUNY), NY (United States); Wilhelm, Jonas [Justus-Liebig-Universitat Giessen, Giessen, Germany; Univ. of Washington, Seattle, WA (United States); Chang, Emmanuel [Univ. of Washington, Seattle, WA (United States); Detmold, William [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Orginos, Kostas [College of William and Mary, Williamsburg, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2018-04-01
Magnetic moments of the octet baryons are computed using lattice QCD in background magnetic fields, including the first treatment of the magnetically coupled Σ0- Λ system. Although the computations are performed for relatively large values of the up and down quark masses, we gain new insight into the symmetries and relations between magnetic moments by working at a three-flavor mass-symmetric point. While the spinflavor symmetry in the large Nc limit of QCD is shared by the naïve constituent quark model, we find instances where quark model predictions are considerably favored over those emerging in the large Nc limit. We suggest further calculations that would shed light on the curious patterns of baryon magnetic moments.
Magnitude of localized magnetic moments in metals
International Nuclear Information System (INIS)
Kiwi, M.; Pestana, E.; Ramirez, R.
1979-01-01
The magnitude of the localized magnetic moment of a transition or rare earth element impurity in a metal is evaluated within the framework of the Anderson model. Rotational invariance is preserved throughout. Graphs of the magnitude of the magnetization as a function of the relevant parameters of the model are provided and discussed. (author)
On the photon anomalous magnetic moment
International Nuclear Information System (INIS)
Perez Rojas, Hugo
2006-01-01
It is shown that, due to radioactive corrections, the photon exhibits a nonzero anomalous magnetic moment whenever it has a nonzero perpendicular momentum component to an external constant magnetic field. Its behaviour is discussed near the first threshold of pair creation. The results might be interesting due to its astrophysical consequenc
Magnetic moment densities in selected UTX compounds
Czech Academy of Sciences Publication Activity Database
Javorský, P.; Schweizer, J.; Givord, F.; Boucherle, J.-X.; Andreev, Alexander V.; Diviš, M.; Lelievre-Berna, E.; Sechovský, V.
2004-01-01
Roč. 350, - (2004), e131-e134 ISSN 0921-4526 R&D Projects: GA ČR GA202/03/0550 Institutional research plan: CEZ:AV0Z1010914 Keywords : uranium compound * polarized neutron scattering * magnetic moment Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.679, year: 2004
Electric and Magnetic Dipole Moments
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.
The anomalous magnetic moment of the muon
Jegerlehner, Friedrich
2017-01-01
This research monograph covers extensively the theory of the muon anomalous magnetic moment and provides estimates of the theoretical uncertainties. The muon anomalous magnetic moment is one of the most precisely measured quantities in elementary particle physics and provides one of the most stringent tests of relativistic quantum field theory as a fundamental theoretical framework. It allows for an extremely precise check of the standard model of elementary particles and of its limitations. This book reviews the present state of knowledge of the anomalous magnetic moment a=(g-2)/2 of the muon. Recent experiments at the Brookhaven National Laboratory now reach the unbelievable precision of 0.5 parts per million, improving the accuracy of previous g-2 experiments at CERN by a factor of 14. In addition, quantum electrodynamics and electroweak and hadronic effects are reviewed. Since non-perturbative hadronic effects play a key role for the precision test, their evaluation is described in detail. Perspectives fo...
Relativistic dynamics of point magnetic moment
Rafelski, Johann; Formanek, Martin; Steinmetz, Andrew
2018-01-01
The covariant motion of a classical point particle with magnetic moment in the presence of (external) electromagnetic fields is revisited. We are interested in understanding extensions to the Lorentz force involving point particle magnetic moment (Stern-Gerlach force) and how the spin precession dynamics is modified for consistency. We introduce spin as a classical particle property inherent to Poincaré symmetry of space-time. We propose a covariant formulation of the magnetic force based on a `magnetic' 4-potential and show how the point particle magnetic moment relates to the Amperian (current loop) and Gilbertian (magnetic monopole) descriptions. We show that covariant spin precession lacks a unique form and discuss the connection to g-2 anomaly. We consider the variational action principle and find that a consistent extension of the Lorentz force to include magnetic spin force is not straightforward. We look at non-covariant particle dynamics, and present a short introduction to the dynamics of (neutral) particles hit by a laser pulse of arbitrary shape.
Theory of anisotropic diamagnetism, local moment magnetization ...
Indian Academy of Sciences (India)
Theory of anisotropic diamagnetism, local moment magnetization and carrier spin-polarization in Pb1-EuTe ... Gopalpur 761 002, India; Department of Physics, Jagannath Institute for Technology and Management, Parlakhemundi 761 211, India; Department of Physics, Berhampur University, Berhampur 760 007, India ...
The Anomalous Magnetic Moment of the Muon
Jegerlehner, Friedrich
2008-01-01
This book reviews the present state of knowledge of the anomalous magnetic moment a=(g-2)/2 of the muon. The muon anomalous magnetic moment amy is one of the most precisely measured quantities in elementary particle physics and provides one of the most stringent tests of relativistic quantum field theory as a fundamental theoretical framework. It allows for an extremely precise check of the standard model of elementary particles and of its limitations. Recent experiments at the Brookhaven National Laboratory now reach the unbelievable precision of 0.5 parts per million, improving the accuracy of previous g-2 experiments at CERN by a factor of 14. A major part of the book is devoted to the theory of the anomalous magnetic moment and to estimates of the theoretical uncertainties. Quantum electrodynamics and electroweak and hadronic effects are reviewed. Since non-perturbative hadronic effects play a key role for the precision test, their evaluation is described in detail. After the overview of theory, the exper...
Field Induced Magnetic Moments in a Metastable Iron-Mercury Alloy
DEFF Research Database (Denmark)
Pedersen, M.S.; Mørup, Steen; Linderoth, Søren
1996-01-01
The magnetic properties of a metastable iron-mercury alloy have been investigated in the temperature range from 5 to 200 K by Mossbauer spectroscopy and magnetization measurements. At low temperature the magnetic moment per iron atom is larger than af alpha-Fe. The effective spontaneous magnetic ....... It was found that the field-induced increase of the magnetic moment in the metastable iron-mecury alloy was about 0.06 Bohr magnetons per iron atom in the temperature range from 5 to 200 K for a field change from 6 to 12 T....
The Magnetic Moment of the Lambda Hyperon
Energy Technology Data Exchange (ETDEWEB)
Schachinger, Lindsay Carol [Rutgers Univ., Piscataway, NJ (United States)
1978-10-01
The magnetic moment of the lambda hyperon has been measured to be· -0.613S±0.0047 nuclear magneton. The experiment was performed in the neutral hyperon beam at the Fermi National Accelerator Laboratory. Three million $\\Lambda^0 \\to p \\pi^-$ decays were detected in a multi-wire proportional chamber spectrometer. The lambda sample, produced inclusively by 400 Gev protons, had an. average momentum of 114 Gev / c and an average polarization of 0.085. This polarization was precessed through angles as large as 153 degrees
The anomalous magnetic moment of the muon
International Nuclear Information System (INIS)
Farley, F.J.M.
1975-01-01
A historical survey of the measurements of the gyromagnetic ratio g of the muon. A brief introduction is given to the theory of the 'anomalous magnetic moment' a equivalent to 1/2(g-2) and its significance is explained. The main part of the review concerns the successive (g-2) experiments to measure a directly, with gradually increasing accuracy. At present experiment and theory agree to (13+-29) parts in 10 9 in g, and the muon still obeys the rules of quantum electrodynamics for a structureless point charge. (author)
Magnetic resonance signal moment determination using the Earth's magnetic field
Fridjonsson, Einar Orn
2015-03-01
We demonstrate a method to manipulate magnetic resonance data such that the moments of the signal spatial distribution are readily accessible. Usually, magnetic resonance imaging relies on data acquired in so-called k-space which is subsequently Fourier transformed to render an image. Here, via analysis of the complex signal in the vicinity of the centre of k-space we are able to access the first three moments of the signal spatial distribution, ultimately in multiple directions. This is demonstrated for biofouling of a reverse osmosis (RO) membrane module, rendering unique information and an early warning of the onset of fouling. The analysis is particularly applicable for the use of mobile magnetic resonance spectrometers; here we demonstrate it using an Earth\\'s magnetic field system.
On the limitations of gyrokinetics: Magnetic moment conservation
Stephens, Cole D.; Brzozowski, Robert W.; Jenko, Frank
2017-10-01
The gyrokinetic theory is a popular and efficient approach to study low-frequency phenomena in magnetized plasmas. Its applicability is rooted in the invariance of a charged particle's magnetic moment. We calculate the maximum non-conservation of this magnetic moment in various elementary combinations of electromagnetic fields. The situation is ameliorated by introducing magnetic moments that account for the drift behavior of the guiding center. Based on these results, we discuss the limitations of gyrokinetics on a quantifiable basis.
Isolating magnetic moments from individual grains within a magnetic assemblage
Béguin, A.; Fabian, K.; Jansen, C.; Lascu, I.; Harrison, R.; Barnhoorn, A.; de Groot, L. V.
2017-12-01
Methods to derive paleodirections or paleointensities from rocks currently rely on measurements of bulk samples (typically 10 cc). The process of recording and storing magnetizations as function of temperature, however, differs for grains of various sizes and chemical compositions. Most rocks, by their mere nature, consist of assemblages of grains varying in size, shape, and chemistry. Unraveling the behavior of individual grains is a holy grail in fundamental rock magnetism. Recently, we showed that it is possible to obtain plausible magnetic moments for individual grains in a synthetic sample by a micromagnetic tomography (MMT) technique. We use a least-squares inversion to obtain these magnetic moments based on the physical locations and dimensions of the grains obtained from a MicroCT scanner and a magnetic flux density map of the surface of the sample. The sample used for this proof of concept, however, was optimized for success: it had a low dispersion of the grains, and the grains were large enough so they were easily detected by the MicroCT scanner. Natural lavas are much more complex than the synthetic sample analyzed so far: the dispersion of the magnetic markers is one order of magnitude higher, the grains differ more in composition and size, and many small (submicron) magnetic markers may be present that go undetected by the MicroCT scanner. Here we present the first results derived from a natural volcanic sample from the 1907-flow at Hawaii. To analyze the magnetic flux at the surface of the sample at room temperature, we used the Magnetic Tunneling Junction (MTJ) technique. We were able to successfully obtain MicroCT and MTJ scans from the sample and isolate plausible magnetic moments for individual grains in the top 70 µm of the sample. We discuss the potential of the MMT technique applied to natural samples and compare the MTJ and SSM methods in terms of work flow and quality of the results.
Quantum tunneling of the magnetic moment in a free nanoparticle
International Nuclear Information System (INIS)
O'Keeffe, M.F.; Chudnovsky, E.M.; Garanin, D.A.
2012-01-01
We study tunneling of the magnetic moment in a particle that has full rotational freedom. Exact energy levels are obtained and the ground-state magnetic moment is computed for a symmetric rotor. The effect of mechanical freedom on spin tunneling manifests itself in a strong dependence of the magnetic moment on the moments of inertia of the rotor. The energy of the particle exhibits quantum phase transitions between states with different values of the magnetic moment. Particles of various shapes are investigated and the quantum phase diagram is obtained. - Highlights: ► We obtain an exact analytical solution of a tunneling spin in a mechanical rotator. ► The quantum phase diagram shows magnetic moment dependence on rotator shape and size. ► Our work explains magnetic properties of free atomic clusters and magnetic molecules.
Quantum tunneling of the magnetic moment in a free nanoparticle
Energy Technology Data Exchange (ETDEWEB)
O' Keeffe, M.F. [Physics Department, Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, New York, 10468-1589 (United States); Chudnovsky, E.M., E-mail: eugene.chudnovsky@lehman.cuny.edu [Physics Department, Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, New York, 10468-1589 (United States); Garanin, D.A. [Physics Department, Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, New York, 10468-1589 (United States)
2012-09-15
We study tunneling of the magnetic moment in a particle that has full rotational freedom. Exact energy levels are obtained and the ground-state magnetic moment is computed for a symmetric rotor. The effect of mechanical freedom on spin tunneling manifests itself in a strong dependence of the magnetic moment on the moments of inertia of the rotor. The energy of the particle exhibits quantum phase transitions between states with different values of the magnetic moment. Particles of various shapes are investigated and the quantum phase diagram is obtained. - Highlights: Black-Right-Pointing-Pointer We obtain an exact analytical solution of a tunneling spin in a mechanical rotator. Black-Right-Pointing-Pointer The quantum phase diagram shows magnetic moment dependence on rotator shape and size. Black-Right-Pointing-Pointer Our work explains magnetic properties of free atomic clusters and magnetic molecules.
Induced Magnetic Moment in Defected Single-Walled Carbon Nanotubes
International Nuclear Information System (INIS)
Liu Hong
2006-01-01
The existence of a large induced magnetic moment in defect single-walled carbon nanotube(SWNT) is predicted using the Green's function method. Specific to this magnetic moment of defect SWNT is its magnitude which is several orders of magnitude larger than that of perfect SWNT. The induced magnetic moment also shows certain remarkable features. Therefore, we suggest that two pair-defect orientations in SWNT can be distinguished in experiment through the direction of the induced magnetic moment at some Specific energy points
Biocompatible magnetic nanoparticles with high magnetic moment for cancer treatment
Sharma, Amit; Qiang, You; Muldoon, Leslie; Meyer, Daniel; Hass, Jamie
2007-05-01
Non-toxic iron oxide naoparticles have extended the boundary in medical world; with size range form 2 to 400 nm they can be compiled with most of the small cells and tissues in living body. We have prepared monodispersive iron-iron oxide core-shell nanoparticles in our novel cluster deposition system. The nanoparticles have very high magnetic moment up to 200 emu/g. To test the nontoxicity and uptake we incubated the nanoparticles coated with dextrin and non-coated iron naoparticles with LXI SCLC lung cancer cells found in rats. Results indicate that both coated and noncoated cells were successfully untaken by the cells indicating that the core-shell nanoparticles are not toxic. Due to the high magnetic moment offered by the nanoparticles we propose that even in low applied external alternating field desired temperature can be reached for hyperthermia treatment in comparison to the commercially available iron oxide nanoparticles (magnetic moment less than 20 emu/g). We also found that our ferromagnetic nanoparticles were uptaken by the cancer cells without adding protamine sulfate, which is normally needed to prevent the coagulation of cells for the commercial nanoparticles. To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.NWS07.B4.5
Spontaneous magnetic alignment behaviour in free-living lizards
Diego-Rasilla, Francisco J.; Pérez-Mellado, Valentín; Pérez-Cembranos, Ana
2017-04-01
Several species of vertebrates exhibit spontaneous longitudinal body axis alignment relative to the Earth's magnetic field (i.e., magnetic alignment) while they are performing different behavioural tasks. Since magnetoreception is still not fully understood, studying magnetic alignment provides evidence for magnetoreception and broadens current knowledge of magnetic sense in animals. Furthermore, magnetic alignment widens the roles of magnetic sensitivity in animals and may contribute to shed new light on magnetoreception. In this context, spontaneous alignment in two species of lacertid lizards ( Podarcis muralis and Podarcis lilfordi) during basking periods was monitored. Alignments in 255 P. muralis and 456 P. lilfordi were measured over a 5-year period. The possible influence of the sun's position (i.e., altitude and azimuth) and geomagnetic field values corresponding to the moment in which a particular lizard was observed on lizards' body axis orientation was evaluated. Both species exhibited a highly significant bimodal orientation along the north-northeast and south-southwest magnetic axis. The evidence from this study suggests that free-living lacertid lizards exhibit magnetic alignment behaviour, since their body alignments cannot be explained by an effect of the sun's position. On the contrary, lizard orientations were significantly correlated with geomagnetic field values at the time of each observation. We suggest that this behaviour might provide lizards with a constant directional reference while they are sun basking. This directional reference might improve their mental map of space to accomplish efficient escape behaviour. This study is the first to provide spontaneous magnetic alignment behaviour in free-living reptiles.
Model independent bounds on magnetic moments of Majorana neutrinos
International Nuclear Information System (INIS)
Bell, Nicole F.; Gorchtein, Mikhail; Ramsey-Musolf, Michael J.; Vogel, Petr; Wang, Peng
2006-01-01
We analyze the implications of neutrino masses for the magnitude of neutrino magnetic moments. By considering electroweak radiative corrections to the neutrino mass, we derive model-independent naturalness upper bounds on neutrino magnetic moments, μ ν , generated by physics above the electroweak scale. For Dirac neutrinos, the bound is several orders of magnitude more stringent than present experimental limits. However, for Majorana neutrinos the magnetic moment contribution to the mass is Yukawa suppressed. The bounds we derive for magnetic moments of Majorana neutrinos are weaker than present experimental limits if μ ν is generated by new physics at ∼1 TeV, and surpass current experimental sensitivity only for new physics scales >10-100 TeV. The discovery of a neutrino magnetic moment near present limits would thus signify that neutrinos are Majorana particles
International Nuclear Information System (INIS)
Sun Jinji; Ren Yuan; Fang Jiancheng
2011-01-01
The paper presents a special configuration of passive axial magnetic bearing with segmented Halbach magnetized array in magnetically suspended control moment gyro (MSCMG). Peculiarity of presented passive axial magnetic bearing is its ability to provide angular stiffness so that it can produce gyro moment when it is used in MSCMG. The MSCMG with this passive axial magnetic bearing can efficiently reduce the power loss when it supplies gyro moment compared with the five degrees of freedom (5-DOF) MSCMG. The characteristics of the suspension force and stiffness of the passive axial magnetic bearing are studied using finite element method (FEM). The performance of the presented passive axial magnetic bearing with Halbach magnetized array is verified by a prototyped MSCMG. - Research highlights: → Passive axial magnetic bearing is used to provide angular stiffness. → Passive axial magnetic bearing is based on repulsion. → Layers Halbach magnetized array realizes higher stiffness per bearing volume. → Passive axial magnetic bearing can provide gyro moment in CMG. → Power loss of MSCMG with PMB does not increase when it provides gyro moment.
Sum rules and systematics for baryon magnetic moments
International Nuclear Information System (INIS)
Lipkin, H.J.
1984-01-01
The new experimental values of hyperon magnetic moments are compared with sum rules predicted from general quark models. Three difficulties encountered are not easily explained by simple models. The isovector contributions of nonstrange quarks to hyperon moments are smaller than the corresponding contribution to nucleon moments, indicating either appreciable configuration mixing in hyperon wave functions and absent in nucleons or an additional isovector contribution beyond that of valence quarks, e.g. from a pion cloud. The large magnitude of the Ψ - moment may indicate that the strange quark contribution to the Ψ moments is considerably larger than the value μ(Λ) predicted by simple models which have otherwise been very successful. The set of controversial values from different experiments of the Σ - moment include a value very close to -1/2μ(Σ + ) which would indicate that strange quarks do not contribute at all to the Σ moments. (orig.)
Sum rules and systematics for baryon magnetic moments
International Nuclear Information System (INIS)
Lipkin, H.J.
1983-11-01
The new experimental values of hyperon magnetic moments are compared with sum rules predicted from general quark models. Three difficulties encountered are not easily explained by simple models. The isovector contributions of nonstrange quarks to hyperon moments are smaller than the corresponding contribution to nucleon moments, indicating either appreciable configuration mixing in hyperon wave functions and absent in nucleons or an additional isovector contribution beyond that of valence quarks; e.g. from a pion cloud. The large magnitude of the THETA - moment may indicate that the strange quark contribution to the THETA moments is considerably larger than the value μ(Λ) predicted by simple models which have otherwise been very successful. The set of controversial values from different experiments of the Σ - moment include a value very close to -(1/2)μ(Σ + ) which would indicate that strange quarks do not contribute at all to the Σ moments. (author)
The relation between anomalous magnetic moment and axial anomaly
International Nuclear Information System (INIS)
Teryaev, O.V.
1990-12-01
The conservation of total angular momentum of spinor particle leads to a simple relation between the famous Schwinger and Adler coefficients determining axial anomaly and anomalous magnetic moment, respectively. (author). 8 refs, 1 fig
The Determination of the Muon Magnetic Moment from Cosmic Rays
Amsler, C.
1974-01-01
Describes an experiment suited for use in an advanced laboratory course in particle physics. The magnetic moment of cosmic ray muons which have some polarization is determined with an error of about five percent. (Author/GS)
Magnetic dipole moments of the heavy tensor mesons in QCD
International Nuclear Information System (INIS)
Aliev, T.M.; Barakat, T.; Savci, M.
2015-01-01
The magnetic dipole moments of the D 2 , and D S 2 , B 2 , and B S 2 heavy tensor mesons are estimated in framework of the light cone QCD sum rules. It is observed that the magnetic dipole moments for the charged mesons are larger than that of its neutral counterpart. It is found that the SU(3) flavor symmetry violation is about 10 % in both b and c sectors. (orig.)
Magnetic moment test report for the model SAR 8108 battery
Ludwig, G. O.; Delbosco, E.; Montes, A.
1988-05-01
The procedures are described for determining the magnetic moment of the Eagle-Picher Model SAR 8108 Battery. The results of a test performed with this battery is presented. The experimental method used was to map the flux density field around the battery. The value of the magnetic moment was evaluated from the experimental data by a numerical procedure based on a spherical harmonic analysis and was found to be 0.050 + or - 0.005 A sq m.
Resonances and dipole moments in dielectric, magnetic, and magnetodielectric cylinders
DEFF Research Database (Denmark)
Dirksen, A.; Arslanagic, Samel; Breinbjerg, Olav
2011-01-01
An eigenfunction solution to the problem of plane wave scattering by dielectric, magnetic, and magnetodielectric cylinders is used for a systematic investigation of their resonances. An overview of the resonances with electric and magnetic dipole moments, needed in, e.g., the synthesis of metamat......An eigenfunction solution to the problem of plane wave scattering by dielectric, magnetic, and magnetodielectric cylinders is used for a systematic investigation of their resonances. An overview of the resonances with electric and magnetic dipole moments, needed in, e.g., the synthesis...
Study of magnetic moments of nuclear excited states at TRISTAN
International Nuclear Information System (INIS)
Hill, J.C.; Wohn, F.K.; Wolf, A.; Berant, Z.; Gill, R.L.; Kruse, H.
1984-01-01
Measurement of the static magnetic dipole moments of nuclear excited states are of interest since they reveal information on nuclear structure not available by other means. A system has been constructed at the TRISTAN separator to measure magnetic dipole moments of excited states in neutron-rich nuclei using the method of perturbed angular correlations (PAC). High magnetic fields are not available through the use of a superconducting magnet. The capability of the TRISTAN system is discussed and the PAC measuring apparatus is described. Final results from recent g factor measurements at TRISTAN on 4 + states in the N = 82 isotones are discussed in some detail. Studies in progress are briefly outlined
Theory of anisotropic diamagnetism, local moment magnetization ...
Indian Academy of Sciences (India)
Keywords. Orbital diamagnetism; magnetization; sp-f hybridization; spin density; diluted mag- netic semiconductors. PACS Nos 75.50 Pp; 75.20 Ck; 75.10 Lp. 1. Introduction. The physics of magnetic impurities in non-magnetic metals abounds in richness and com- plexity of phenomena and has been studied for decades.
Intrinsic magnetism and spontaneous band gap opening in bilayer silicene and germanene.
Wang, Xinquan; Wu, Zhigang
2017-01-18
It has been long sought to create magnetism out of simple non-magnetic materials, such as silicon and germanium. Here we show that intrinsic magnetism exists in bilayer silicene and germanene with no need to cut, etch, or dope. Unlike bilayer graphene, strong covalent interlayer bonding formed in bilayer silicene and germanene breaks the original π-bonding network of each layer, leaving the unbonded electrons unpaired and localized to carry magnetic moments. These magnetic moments then couple ferromagnetically within each layer while antiferromagnetically across two layers, giving rise to an infinite magnetic sheet with structural integrity and magnetic homogeneity. Furthermore, this unique magnetic ordering results in fundamental band gaps of 0.55 eV and 0.32 eV for bilayer silicene and germanene, respectively. The integration of intrinsic magnetism and spontaneous band gap opening makes bilayer silicene and germanene attractive for future nanoelectronics as well as spin-based computation and data storage.
Magnetic moments of composite quarks and leptons: further difficulties
International Nuclear Information System (INIS)
Lipkin, H.J.
1980-05-01
The previously noted difficulty of obtaining Dirac magnetic moments in composite models with two basic building blocks having different charges is combined with the observation by Shaw et al., that a light bound fermion state built from heavy constituents must have the Dirac moment in a renormalizable theory. The new constraint on any model that builds leptons from two fundamental fields bound by non-electromagnetic forces is that the ratio of the magnetic moment to the total charge of the bound state is independent of the values of the charges of the constituents; e.g., such a bound state of a spin-1/2 fermion and a scalar boson will have the same magnetic moment if the fermion is neutral and the boson has charge -e or vice versa
Theory of anisotropic diamagnetism, local moment magnetization ...
Indian Academy of Sciences (India)
The relative spin-density of carriers increases with increase in the magnetic field strength and magnetic ion concentration. The agreement with experiment where ... susceptibility for a real system has always been a daunting exercise because of the enor- mous complexity associated with the problem. Pb1 xEuxTe is a ...
SNO results and neutrino magnetic moment solution to the solar ...
Indian Academy of Sciences (India)
that the solar neutrino deficit is due to the interaction of neutrino transition magnetic moment with the solar magnetic ... Another new feature in the analysis is that for the global analysis, we have replaced the spectrum by its centroid. ... rise to mean potentials Va for neutrinos which are proportional to the number density of.
SNO results and neutrino magnetic moment solution to the solar ...
Indian Academy of Sciences (India)
Kamiokande (SK) experiments (1258 days) and also the new results that came from Sudbury Neu- trino Observatory (SNO) charge current (CC) and elastic scattering (ES) experiments considering that the solar neutrino deficit is due to the interaction of neutrino transition magnetic moment with the solar magnetic field.
Determination of the magnetic moment of $^{140}$Pr
Kowalska, M; Kreim, K D; Krieger, A R; Litvinov, Y
We propose to measure the nuclear magnetic moment of the neutron-deficient isotope $^{140}$Pr using collinear laser spectroscopy at the COLLAPS experiment. This nuclide is one of two nuclear systems for which a modulated electron capture decay has been observed in hydrogen-like ions in a storage ring. The firm explanation of the observed phenomenon is still missing but some hypotheses suggest an interaction of the unpaired electron with the surrounding magnetic fields of the ring. In order to verify or discard these hypotheses the magnetic moment of $^{140}$Pr is required since this determines the energy of the 1s hyperfine splitting.
Possibility of a new determination of the magnetic moment of the neutron
International Nuclear Information System (INIS)
Miller, P.D.
1974-01-01
In the lecture the development of an electric dipole moment spectrometer for the determination of the magnetic moment of the neutron is described. The possibility of a more accurate determination of the magnetic moment with the apparatus is discussed
Analysis of dynamical corrections to baryon magnetic moments
International Nuclear Information System (INIS)
Ha, Phuoc; Durand, Loyal
2003-01-01
We present and analyze QCD corrections to the baryon magnetic moments in terms of the one-, two-, and three-body operators which appear in the effective field theory developed in our recent papers. The main corrections are extended Thomas-type corrections associated with the confining interactions in the baryon. We investigate the contributions of low-lying angular excitations to the baryon magnetic moments quantitatively and show that they are completely negligible. When the QCD corrections are combined with the nonquark model contributions of the meson loops, we obtain a model which describes the baryon magnetic moments within a mean deviation of 0.04 μ N . The nontrivial interplay of the two types of corrections to the quark-model magnetic moments is analyzed in detail, and explains why the quark model is so successful. In the course of these calculations, we parametrize the general spin structure of the j=(1/2) + baryon wave functions in a form which clearly displays the symmetry properties and the internal angular momentum content of the wave functions, and allows us to use spin-trace methods to calculate the many spin matrix elements which appear in the expressions for the baryon magnetic moments. This representation may be useful elsewhere
Magnetotransport in Layered Dirac Fermion System Coupled with Magnetic Moments
Iwasaki, Yoshiki; Morinari, Takao
2018-03-01
We theoretically investigate the magnetotransport of Dirac fermions coupled with localized moments to understand the physical properties of the Dirac material EuMnBi2. Using an interlayer hopping form, which simplifies the complicated interaction between the layers of Dirac fermions and the layers of magnetic moments in EuMnBi2, the theory reproduces most of the features observed in this system. The hysteresis observed in EuMnBi2 can be caused by the valley splitting that is induced by the spin-orbit coupling and the external magnetic field with the molecular field created by localized moments. Our theory suggests that the magnetotransport in EuMnBi2 is due to the interplay among Dirac fermions, localized moments, and spin-orbit coupling.
Fluxonium-Based Artificial Molecule with a Tunable Magnetic Moment
Directory of Open Access Journals (Sweden)
A. Kou
2017-08-01
Full Text Available Engineered quantum systems allow us to observe phenomena that are not easily accessible naturally. The LEGO®-like nature of superconducting circuits makes them particularly suited for building and coupling artificial atoms. Here, we introduce an artificial molecule, composed of two strongly coupled fluxonium atoms, which possesses a tunable magnetic moment. Using an applied external flux, one can tune the molecule between two regimes: one in which the ground-excited state manifold has a magnetic dipole moment and one in which the ground-excited state manifold has only a magnetic quadrupole moment. By varying the applied external flux, we find the coherence of the molecule to be limited by local flux noise. The ability to engineer and control artificial molecules paves the way for building more complex circuits for quantum simulation and protected qubits.
Fluxonium-Based Artificial Molecule with a Tunable Magnetic Moment
Kou, A.; Smith, W. C.; Vool, U.; Brierley, R. T.; Meier, H.; Frunzio, L.; Girvin, S. M.; Glazman, L. I.; Devoret, M. H.
2017-07-01
Engineered quantum systems allow us to observe phenomena that are not easily accessible naturally. The LEGO®-like nature of superconducting circuits makes them particularly suited for building and coupling artificial atoms. Here, we introduce an artificial molecule, composed of two strongly coupled fluxonium atoms, which possesses a tunable magnetic moment. Using an applied external flux, one can tune the molecule between two regimes: one in which the ground-excited state manifold has a magnetic dipole moment and one in which the ground-excited state manifold has only a magnetic quadrupole moment. By varying the applied external flux, we find the coherence of the molecule to be limited by local flux noise. The ability to engineer and control artificial molecules paves the way for building more complex circuits for quantum simulation and protected qubits.
Moment switching in nanotube magnetic force probes
Kirtley, J.R.; Deng, Z.; Luan, L.; Yenilmez, E.; Dai, H.; Moler, K.A.
2007-01-01
Magnetic images of high density vertically recorded media using metal-coated carbon nanotube tips exhibit a doubling of the spatial frequency under some conditions (Deng et al 2004 Appl. Phys. Lett. 85 6263). Here we demonstrate that this spatial frequency doubling is due to the switching of the
Magnetic moment investigation by frequency mixing techniques.
Teliban, I; Thede, C; Chemnitz, S; Bechtold, C; Quadakkers, W J; Schütze, M; Quandt, E
2009-11-01
Gas turbines and other large industrial equipment are subjected to high-temperature oxidation and corrosion. Research and development of efficient protective coatings is the main task in the field. Also, knowledge about the depletion state of the coating during the operation time is important. To date, practical nondestructive methods for the measurement of the depletion state do not exist. By integrating magnetic phases into the coating, the condition of the coating can be determined by measuring its magnetic properties. In this paper, a new technique using frequency mixing is proposed to investigate the thickness of the coatings based on their magnetic properties. A sensor system is designed and tested on specific magnetic coatings. New approaches are proposed to overcome the dependency of the measurement on the distance between coil and sample that all noncontact techniques face. The novelty is a low cost sensor with high sensibility and selectivity which can provide very high signal-to-noise ratios. Prospects and limitations are discussed for future use of the sensor in industrial applications.
Effective particle magnetic moment of multi-core particles
Energy Technology Data Exchange (ETDEWEB)
Ahrentorp, Fredrik; Astalan, Andrea; Blomgren, Jakob; Jonasson, Christian [Acreo Swedish ICT AB, Arvid Hedvalls backe 4, SE-411 33 Göteborg (Sweden); Wetterskog, Erik; Svedlindh, Peter [Department of Engineering Sciences, Uppsala University, Box 534, SE-751 21 Uppsala (Sweden); Lak, Aidin; Ludwig, Frank [Institute of Electrical Measurement and Fundamental Electrical Engineering, TU Braunschweig, D‐38106 Braunschweig Germany (Germany); IJzendoorn, Leo J. van [Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Westphal, Fritz; Grüttner, Cordula [Micromod Partikeltechnologie GmbH, D ‐18119 Rostock (Germany); Gehrke, Nicole [nanoPET Pharma GmbH, D ‐10115 Berlin Germany (Germany); Gustafsson, Stefan; Olsson, Eva [Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg (Sweden); Johansson, Christer, E-mail: christer.johansson@acreo.se [Acreo Swedish ICT AB, Arvid Hedvalls backe 4, SE-411 33 Göteborg (Sweden)
2015-04-15
In this study we investigate the magnetic behavior of magnetic multi-core particles and the differences in the magnetic properties of multi-core and single-core nanoparticles and correlate the results with the nanostructure of the different particles as determined from transmission electron microscopy (TEM). We also investigate how the effective particle magnetic moment is coupled to the individual moments of the single-domain nanocrystals by using different measurement techniques: DC magnetometry, AC susceptometry, dynamic light scattering and TEM. We have studied two magnetic multi-core particle systems – BNF Starch from Micromod with a median particle diameter of 100 nm and FeraSpin R from nanoPET with a median particle diameter of 70 nm – and one single-core particle system – SHP25 from Ocean NanoTech with a median particle core diameter of 25 nm.
Effective particle magnetic moment of multi-core particles
International Nuclear Information System (INIS)
Ahrentorp, Fredrik; Astalan, Andrea; Blomgren, Jakob; Jonasson, Christian; Wetterskog, Erik; Svedlindh, Peter; Lak, Aidin; Ludwig, Frank; IJzendoorn, Leo J. van; Westphal, Fritz; Grüttner, Cordula; Gehrke, Nicole; Gustafsson, Stefan; Olsson, Eva; Johansson, Christer
2015-01-01
In this study we investigate the magnetic behavior of magnetic multi-core particles and the differences in the magnetic properties of multi-core and single-core nanoparticles and correlate the results with the nanostructure of the different particles as determined from transmission electron microscopy (TEM). We also investigate how the effective particle magnetic moment is coupled to the individual moments of the single-domain nanocrystals by using different measurement techniques: DC magnetometry, AC susceptometry, dynamic light scattering and TEM. We have studied two magnetic multi-core particle systems – BNF Starch from Micromod with a median particle diameter of 100 nm and FeraSpin R from nanoPET with a median particle diameter of 70 nm – and one single-core particle system – SHP25 from Ocean NanoTech with a median particle core diameter of 25 nm
Precise Determination of the Strangeness Magnetic Moment of the Nucleon
Energy Technology Data Exchange (ETDEWEB)
Leinweber, D B; Boinepalli, S; Cloet, I C; Thomas, A W; Williams, A G; Young, R D; Zanotti, J M; Zhang, J B
2005-06-01
By combining the constraints of charge symmetry with new chiral extrapolation techniques and recent low mass lattice QCD simulations of the individual quark contributions to the magnetic moments of the nucleon octet, we obtain a precise determination of the strange magnetic moment of the proton. The result, namely G{sub M}{sup s} = -0.051 +/- 0.021 mu{sub N}, is consistent with the latest experimental measurements but an order of magnitude more precise. This poses a tremendous challenge for future experiments.
The anomalous magnetic moment of the electron
International Nuclear Information System (INIS)
Awobode, A.M.
2002-05-01
The gyromagnetic ratio g of an electron is calculated by taking the non-relativistic limit of a newly proposed extension of the Dirac Hamiltonian coupled to a magnetic field. It is observed that the calculated g is greater than 2; the Dirac theory had predicted that g=2 in sharp contradiction with accurate experimental observations. The additional quantity (g-2)/2≡δ∼(1.6x10 -3 ) is shown here to be due to an extra term which appears in the reduced Hamiltonian, as a consequence of the modification of the rest energy. No divergences are encountered in the calculations described. (author)
Tuning the magnetic moments in zigzag graphene nanoribbons
DEFF Research Database (Denmark)
Chen, Jingzhe; Vanin, Marco; Hu, Yibin
2012-01-01
We report a systematic theoretical investigation of the effects of metal substrates on the local magnetic moments of zigzag graphene nanoribbons (ZGNRs). Representative metal surfaces of Au, Pt, Ni, Cu, Al, Ag, and Pd have been analyzed from atomic first principles. Results show that the local...... hybridization between the metal states and the nonbonding π orbital of the ZGNRs; thereby the tuning effect is reduced. We identify the microscopic physical reason behind the bias tuning of the magnetic properties of the ZGNRs....
Magnetic moments of Jsup(P) = 1/2+ baryons in broken SU(8)
International Nuclear Information System (INIS)
Verma, R.C.
1981-01-01
Symmetry breaking effects on the magnetic moments of baryons are studied in the SU(8) framework. We obtain a low value of μ(Σ + ) in agreement with a recent experiment. The transition moment (p|μ|Δ + ) seems to require isospin breaking , which also improves the overall fit to magnetic moments. Charmed baryon magnetic moments are calculated with and without isospin breaking. (author)
Electric charge quantization and the muon anomalous magnetic moment
International Nuclear Information System (INIS)
Pires, C.A.S. de; Rodrigues da Silva, P.S.
2002-01-01
We investigate some proposals to solve the electric charge quantization puzzle that simultaneously explain the recent measured deviation on the muon anomalous magnetic moment. For this we assess extensions of the electro-weak standard model spanning modifications on the scalar sector only. It is interesting to verify that one can have modest extensions which easily account for the solution for both problems
E6-lepton mixing and lepton magnetic moment
International Nuclear Information System (INIS)
Vendramin, I.
1988-01-01
The contributions to the lepton magnetic moment due to the E 6 -exotic fermions and an extra vector boson Z' have been considered. Using the experimental limits on the E 6 -lepton mixing angles, these contributions are at least one order of magnitude smaller than the standard-model ones
Masses and magnetic moments of triple heavy flavour baryons in ...
Indian Academy of Sciences (India)
Using the spin-flavour structure of the constituting quarks and by defining effective mass of the confined quarks within the baryons, the magnetic moments are computed with no additional free parameters. Keywords. Hypercentral constituent quark model; charmed and beauty baryons; hyper-. Coulomb plus power potential; ...
On verifying magnetic dipole moment of a magnetic torquer by experiments
Kuyyakanont, Aekjira; Kuntanapreeda, Suwat; Fuengwarodsakul, Nisai H.
2018-01-01
Magnetic torquers are used for the attitude control of small satellites, such as CubeSats with Low Earth Orbit (LEO). During the design of magnetic torquers, it is necessary to confirm if its magnetic dipole moment is enough to control the satellite attitude. The magnetic dipole moment can affect the detumbling time and the satellite rotation time. In addition, it is also necessary to understand how to design the magnetic torquer for operation in a CubeSat under the space environment at LEO. This paper reports an investigation of the magnetic dipole moment and the magnetic field generated by a circular air-coil magnetic torquer using experimental measurements. The experiment testbed was built on an air-bearing under a magnetic field generated by a Helmholtz coil. This paper also describes the procedure to determine and verify the magnetic dipole moment value of the designed circular air-core magnetic torquer. The experimental results are compared with the design calculations. According to the comparison results, the designed magnetic torquer reaches the required magnetic dipole moment. This designed magnetic torquer will be applied to the attitude control systems of a 1U CubeSat satellite in the project “KNACKSAT.”
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
Constraining the neutrino magnetic dipole moment from white dwarf pulsations
Energy Technology Data Exchange (ETDEWEB)
Córsico, A.H.; Althaus, L.G. [Grupo de Evolución Estelar y Pulsaciones, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Paseo del Bosque s/n, (1900) La Plata (Argentina); Bertolami, M.M. Miller [Instituto de Astrofísica La Plata, CONICET-UNLP, Paseo del Bosque s/n, (1900) La Plata (Argentina); Kepler, S.O. [Departamento de Astronomia, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, Porto Alegre 91501-970, RS (Brazil); García-Berro, E., E-mail: acorsico@fcaglp.unlp.edu.ar, E-mail: althaus@fcaglp.unlp.edu.ar, E-mail: marcelo@MPA-Garching.MPG.DE, E-mail: kepler@if.ufrgs.br, E-mail: enrique.garcia-berro@upc.edu [Departament de Física Aplicada, Universitat Politècnica de Catalunya, c/Esteve Terrades 5, 08860, Castelldefels (Spain)
2014-08-01
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{sub 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{sub ν} ∼< 10{sup -11} μ{sub 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.
Limits on the scaling of nucleon magnetic moments in nuclei
International Nuclear Information System (INIS)
Ericson, T.E.O.; State Univ. of New York, Stony Brook; Richter, A.; State Univ. of New York, Stony Brook
1987-01-01
In view of the suggestion that nucleon magnetic moments inside nuclei may be modified due to a rescaling of the nucleon size, we investigate empirically how large such an effect can be. The method is based on a nearly model-independent scaling relation between the axial vector matrix element and the main part of the corresponding magnetic dipole matrix element supplemented by a small and well understood contribution from the one-pion exchange current. Taking the mass A = 3 and 12 systems as examples the upper limit, for such a change of the nucleon magnetic moment inside nuclei is found to be about 2%, considerably smaller than previous estimates in the literature. (orig.)
Gate-dependent orbital magnetic moments in carbon nanotubes
DEFF Research Database (Denmark)
Jespersen, Thomas Sand; Grove-Rasmussen, Kasper; Flensberg, Karsten
2011-01-01
We investigate how the orbital magnetic moments of electron and hole states in a carbon nanotube quantum dot depend on the number of carriers on the dot. Low temperature transport measurements are carried out in a setup where the device can be rotated in an applied magnetic field, thus enabling...... accurate alignment with the nanotube axis. The field dependence of the level structure is measured by excited state spectroscopy and excellent correspondence with a single-particle calculation is found. In agreement with band structure calculations we find a decrease of the orbital magnetic moment...... with increasing electron or hole occupation of the dot, with a scale given by the band gap of the nanotube....
Reversible 90-Degree Rotation of Fe Magnetic Moment Using Hydrogen.
Hsu, Chuan-Che; Chang, Po-Chun; Chen, Yi-Hua; Liu, Chak-Ming; Wu, Chun-Te; Yen, Hung-Wei; Lin, Wen-Chin
2018-02-19
[Pd/Fe] 2 multilayers were deposited on a flat MgO(001) to study the effect of hydrogen on magnetic interlayer coupling. Complex magnetic hysteresis behavior, including single, double, and triple loops, were measured as a function of the azimuthal angle in a longitudinal and transverse direction. With a combination of a 2-fold magnetic anisotropy energy (MAE) in the bottom-Fe and a 4-fold MAE in the top-Fe, the complex magnetic hysteresis behavior could be clearly explained. Two well-split hysteresis loops with almost zero Kerr remanence were measured by choosing a suitable Pd thickness and applying the magnetic field perpendicular to the easy axis of the bottom-Fe. The split double loops originated from the 90°-rotation of the top-Fe moment. On exposure to a hydrogen gas atmosphere, the separation of the two minor loops increased, indicating that Pd-hydride formation enhanced the ferromagnetic coupling between the two Fe layers. Based on these observations, we proposed that, by applying a suitable constant magnetic field, the top-Fe moment could undergo reversible 90°-rotation following hydrogen exposure. The results suggest that the Pd space layer used for mediating the magnetic interlayer coupling is sensitive to hydrogen, and therefore, the multilayer system can function as a giant magnetoresistance-type sensor suitable for hydrogen gas.
Magnetic moments and non-Fermi-liquid behavior in quasicrystals
Andrade, Eric
Motivated by the intrinsic non-Fermi-liquid behavior observed in the heavy-fermion quasicrystal Au51Al34Yb15, we study the low-temperature behavior of dilute magnetic impurities placed in metallic quasicrystals. We find that a large fraction of the magnetic moments are not quenched down to very low temperatures, leading to a power-law distribution of Kondo temperatures, accompanied by a non-Fermi-liquid behavior, in a remarkable similarity to the Kondo-disorder scenario found in disordered heavy-fermion metals. This work was supported by FAPESP (Brazil) Grant No. 2013/00681-8.
International Nuclear Information System (INIS)
Zhu Zhenghe; Luo Deli; Feng Kaiming
2013-01-01
The present work is to calculate the magnetic thermodynamically functions, i.e. energy, the intensity of magnetization, enthalpy, entropy and Gibbs function for nuclear magnetic moments of T, D and neutron n at 2 T and 1, 50, 100 and 150 K from partition functions. It is shown that magnetic saturation of thermonuclear plasma does not easily occur for nuclear magneton is only of 10 -3 of Bohr magneton. The work done by magnetic field is considerable. (authors)
Directory of Open Access Journals (Sweden)
A.V. Getman
2013-12-01
Full Text Available Theoretical aspects of an experimental determination method for residual and inductive magnetic moments of a technical object are considered. As input data, the technical object magnetic induction signatures obtained under its linear movement near a pair of three-component sensors are used. A magnetic signature integration technique based on spatial harmonic analysis of the magnetic field represented by twenty-four multipole coefficients is introduced.
Simple optical measurement of the magnetic moment of magnetically labeled objects
Energy Technology Data Exchange (ETDEWEB)
Heidsieck, Alexandra, E-mail: aheidsieck@tum.de [Zentralinstitut für Medizintechnik, Technische Universität München (Germany); Rudigkeit, Sarah [Physics Department, Technische Universität München (Germany); Rümenapp, Christine; Gleich, Bernhard [Zentralinstitut für Medizintechnik, Technische Universität München (Germany)
2017-04-01
The magnetic moment of magnetically labeled cells, microbubbles or microspheres is an important optimization parameter for many targeting, delivery or separation applications. The quantification of this property is often difficult, since it depends not only on the type of incorporated nanoparticle, but also on the intake capabilities, surface properties and internal distribution. We describe a method to determine the magnetic moment of those carriers using a microscopic set-up and an image processing algorithm. In contrast to other works, we measure the diversion of superparamagnetic nanoparticles in a static fluid. The set-up is optimized to achieve a homogeneous movement of the magnetic carriers inside the magnetic field. The evaluation is automated with a customized algorithm, utilizing a set of basic algorithms, including blob recognition, feature-based shape recognition and a graph algorithm. We present example measurements for the characteristic properties of different types of carriers in combination with different types of nanoparticles. Those properties include velocity in the magnetic field as well as the magnetic moment. The investigated carriers are adherent and suspension cells, while the used nanoparticles have different sizes and coatings to obtain varying behavior of the carriers. - Highlights: • Determination of the magnetic moment of magnetic carriers. • optimized set-up achieve a homogeneous movement. • Automated evaluation with a customized algorithm. • example measurements for the properties of nanoparticle-loaded cells.
The magnetic moments of the proton and the antiproton
Ulmer, S.; Blaum, K.; Braeuninger, S.; Franke, K.; Kracke, H.; Leiteritz, C.; Matsuda, Y.; Nagahama, H.; Ospelkaus, C.; Rodegheri, C.C.; Quint, W.; Schneider, G.; Smorra, C.; Van Gorp, S.; Walz, J.; Yamazaki, Y.
2014-01-01
Recent exciting progress in the preparation and manipulation of the motional quantum states of a single trapped proton enabled the first direct detection of the particle's spin state. Based on this success the proton magnetic moment $\\mu_p$ was measured with ppm precision in a Penning trap with a superimposed magnetic field inhomogeneity. An improvement by an additional factor of 1000 in precision is possible by application of the so-called double Penning trap technique. In a recent paper we reported the first demonstration of this method with a single trapped proton, which is a major step towards the first direct high-precision measurement of $\\mu_p$. The techniques required for the proton can be directly applied to measure the antiproton magnetic moment $\\mu_{\\bar{p}}$. An improvement in precision of $\\mu_{\\bar{p}}$ by more than three orders of magnitude becomes possible, which will provide one of the most sensitive tests of CPT invariance. To achieve this research goal we are currently setting up the Baryo...
Magnetic dipole moments of odd-odd lanthanides
International Nuclear Information System (INIS)
Sharma, S.D.; Gandhi, R.
1988-01-01
Magnetic dipole moments of odd-odd lanthanides. Collective model of odd-odd nuclei is applied to predict the magnetic dipole moments, (μ) of odd-odd lanthanides. A simplified version of expression for μ based on diagonalisation of Hamiltonian (subsequent use of eigenvectors to compute μ) is developed for cases of ground state as well as excited states using no configuration mixing and is applied to the cases of odd-odd lanthanides. The formulae applied to the eleven (11) cases of ground states show significant improvement over the results obtained using shell model. Configuration mixing and coriolis coupling is expected to cause further improvement in the results. On comparing the earlier work in this direction the present analysis has clarified that in the expression μ the projection factors have different signs for the case I=Ωp - Ωn and I=Ωn - Ωp, and sign of μ is negative in general in the second case while it is positive in all others of spin projection alignments. Although the general expression holds for excited states as well but in lanthanide region, the experimental reports of magnetic dipole moments of excite states (band heads of higher rational sequences) are not available except in case of five (5) neutron resonance states which cannot be handled on the basis of the present approach with no configuration mixing. Although in the present discussion, the model could not be applied to excited states but the systematics of change in its magnitude with increasing spin at higher rational states is very well understood. The particle part supressed under faster rotation of the nuclear core and thus finally at higher spin I, the value μ is given by μ=g c I (same as in case of even-even nuclei). These systematics are to be verified whenever enough data for higher excited states are available. (author). 11 refs
International Nuclear Information System (INIS)
Nelson, D.H.; Barale, P.J.; Green, M.I.; Van Dyke, D.A.
1987-09-01
Since May 1985, The Magnetic Measurements Engineering Group at LBL has measured and sorted a total of 3834 permanent magnet blocks. These magnetic blocks have been used in the construction of various successful beam-line elements including dipoles, quadrupoles, and wigglers. We report on observed variations in magnetic moments among blocks supplied by five manufacturers, describe the operational capabilities (accuracy, precision, and resolution) of the LBL Magnetic-moment Measurement and Sorting System (MMSS), cite the results of comparative calibrations by permanent-magnet manufacturers and other National Laboratories, and suggest criteria for automating the MMSS for measuring the large number of permanent-magnet blocks required for the insertion devices for the projected LBL 1-2 GeV Synchrotron Radiation Source. 14 refs., 2 figs., 2 tabs
Table of Nuclear Magnetic Dipole and Electric Quadrupole Moments
International Nuclear Information System (INIS)
Stone, N.J.
2011-04-01
This Table is a compilation of experimental measurements of static magnetic dipole and electric quadrupole moments of ground states and excited states of atomic nuclei throughout the periodic table. To aid identification of the states, their excitation energy, half-life, spin and parity are given, along with a brief indication of the method and any reference standard used in the particular measurement. The literature search covers the period to late 2010. Many of the entries prior to 1988 follow those in Raghavan P., Atomic and Nuclear Data Tables 42, 189 (1989). (author)
Table of Nuclear Magnetic Dipole and Electric Quadrupole Moments
International Nuclear Information System (INIS)
Stone, N.J.
2014-02-01
This Table is a compilation of experimental measurements of static magnetic dipole and electric quadrupole moments of ground states and excited states of atomic nuclei throughout the periodic table. To aid identification of the states, their excitation energy, half-life, spin and parity are given, along with a brief indication of the method and any reference standard used in the particular measurement. The literature search covers the period to early 2014. Many of the entries prior to 1988 follow those in Raghavan P., Atomic and Nuclear Data Tables 42, 189 (1989). (author)
Magnetic moment of extremely proton-rich nucleus 23Al
International Nuclear Information System (INIS)
Nagatomo, T; Matsuta, K; Ozawa, A; Nakashima, Y; Matsumiya, R; Mihara, M; Yasuno, T; Chiba, A; Yamada, K; Momota; Ohtsubo, T; Ohta, M; Shinojima, D; Izumikawa, T; Tanaka, H; Yamaguchi, T; Nakajima, S; Maemura, H; Muranaka, K; Kumashiro, S; Fujiwara, H; Yoshida, K; Sumikama, T; Tanaka, K; Ogura, M; Minamisono, K; Fukuda, M; Minamisono, T; Nojiri, Y; Suzuki, T; Tanihata, I; Alonso, J R; Krebs, G F; Symons, T J M
2005-01-01
The g-factor of the extremely proton-rich nucleus 23 Al (T 1/2 = 0.47 s) has been measured by means of the β-NMR method for the first time. The g-factor were determined as |g| = 1.557(88) from the obtained NMR spectra. From the comparison between the experimental value and the shell model calculation, the spin parity of the ground state of 23 Al was determined as I π = 5/2 + . Thus, the magnetic moment of 23 Al was determined as vertical bar μvertical bar = 3.89(22)μ N
Shell structure of potassium isotopes deduced from their magnetic moments
Papuga, J.; Kreim, K; Barbieri, C; Blaum, K; De Rydt, M; Duguet, T; Garcia Ruiz, R F; Heylen, H; Kowalska, M; Neugart, R; Neyens, G; Nortershauser, W; Rajabali, M M; Sanchez, R; Smirnova, N; Soma, V; Yordanov, D T
2014-09-29
$\\textbf{Background:}$ Ground-state spins and magnetic moments are sensitive to the nuclear wave function, thus they are powerful probes to study the nuclear structure of isotopes far from stability. \\\\ \\\\ $\\textbf{Purpose:}$ Extend our knowledge about the evolution of the $1/2^+$ and $3/2^+$ states for K isotopes beyond the $N = 28$ shell gap. \\\\ \\\\ $\\textbf{Method:}$ High-resolution collinear laser spectroscopy on bunched atomic beams. \\\\ \\\\ $\\textbf{Results:}$ From measured hyperfine structure spectra of K isotopes, nuclear spins and magnetic moments of the ground states were obtained for isotopes from $N = 19$ up to $N = 32$. In order to draw conclusions about the composition of the wave functions and the occupation of the levels, the experimental data were compared to shell-model calculations using SDPF-NR and SDPF-U effective interactions. In addition, a detailed discussion about the evolution of the gap between proton $1d_{3/2}$ and $2s_{1/2}$ in the shell model and $\\textit{ab initio}$ framework is al...
Molecular alloy with diluted magnetic moments-molecular Kondo system.
Idobata, Yuki; Zhou, Biao; Kobayashi, Akiko; Kobayashi, Hayao
2012-01-18
[Ni(1-x)Cu(x)(tmdt)(2)] (tmdt = trimethylenetetrathiafulvalenedithiolate) was prepared for realizing molecular Kondo systems. Magnetic moments (S = (1)/(2)) are considered to exist at the central {CuS(4)} parts of Cu(tmdt)(2) molecules. The χT-versus-T curve of the system with x ≈ 0.15 showed a broad peak at ~10 K. The decrease in the χT value below 10 K is consistent with a singlet ground state, as expected for a Kondo system. However, in the system with x ≈ 0.27, the χT value decreased when the temperature was lowered to 2 K, indicating antiferromagnetic interactions between magnetic moments through π-d interactions. Although the susceptibility anomaly suggested that the π-d interactions become important at T K. However, the differential resistivity Δρ(T) = ρ(obs) - ρ(L)(T) showed a logarithmic resistivity increase at 8-20 K with decreasing temperature, where ρ(L)(T) is a fitted function of ρ(obs) obtained at T > 50 K that is considered to represent approximately the temperature dependence of the resistivity without spin scattering of the conduction electrons. © 2011 American Chemical Society
Spin moments, orbital moments and magnetic anisotropy of finite-length Co wires deposited on Pd(110)
International Nuclear Information System (INIS)
Felix-Medina, R; Dorantes-Davila, J; Pastor, G M
2002-01-01
The ground-state spin moments (S z ), orbital moments (L z ) and magnetic anisotropy energy (MAE) of Co N one-dimensional (1D) clusters (N≤12) deposited on the Pd(110) surface are determined in the framework of a self-consistent, real-space tight-binding method. Remarkably large total magnetic moments per Co atom, M z =(2(S z )+(L z ))/N=2.8-2.9 μ B , are obtained, which can be understood as the result of three physically distinct effects. The first and leading contribution is given by the local spin moments (S iz ) at the Co atoms i=1, N (2(S iz ) Co ≅1.6 μ B ). Second, significant spin moments are induced at the Pd atoms i > N close to the Co-Pd interface, which amount to about 25% of M z (2(S iz ) Pd =0.2-0.3 μ B ). Finally, enhanced orbital magnetic moments (L iz ) are responsible for approximately 20% of M z . In the case of the Co atoms, (L iz ) Co =0.28-0.33 μ B is almost a factor of three larger than the Co bulk orbital moment, while in Pd atoms (L iz ) Pd =0.05 μ B represents about 15% of the total local moment μ iz =2(S iz )+(L iz ). These results and the associated MAEs are analysed from a local perspective. The role of the cluster-surface interactions is discussed by comparison with the corresponding results for free-standing wires. Particularly in the case of monatomic 1D Co chains we observe that the lowest-energy magnetization direction (easy axis) changes from in line to off plane upon deposition on Pd(110). Wire-substrate hybridizations are therefore crucial for the magneto-anisotropic behaviour of 1D magnetic nanostructures on metallic substrates
International Nuclear Information System (INIS)
Oztekin, E.
2010-01-01
In this study, magnetic multipole moment integrals are calculated by using Slater type orbitals (STOs), Fourier transform and translation formulas. Firstly, multipole moment operators which appear in the three-center magnetic multipole moment integrals are translated to b-center from 0-center. So, three-center magnetic multipole moment integrals have been reduced to the two-center. Then, the obtained analytical expressions have been written in terms of overlap integrals. When the magnetic multipole moment integrals calculated, matrix representations for x-, y- and z-components of multipole moments was composed and every component was separately calculated to analytically. Consequently, magnetic multipole moment integrals are also given in terms of the same and different screening parameters.
The effect of a neutrino magnetic moment on nuclear excitation processes
International Nuclear Information System (INIS)
Dodd, A.C.; Papageorgiu, E.; Ranfone, S.
1991-01-01
We discuss the sensitivity of magnetic transitions in nuclei like 12 C, to a small neutrino magnetic moment, and its implications for current and future experiments. We also point out that coherent neutrino-nuclear elastic scattering in low-temperature detectors, might improve the present laboratory bounds on the neutrino magnetic moment by an order of magnitude. (orig.)
Relativistic correction to the deuteron magnetic moment and angular condition
International Nuclear Information System (INIS)
Kondratyuk, L.A.; Strikman, M.I.
1983-01-01
The relativistic correction (RC) to the deuteron magnetic moment μsub(d) is investigated using the light-cone dynamics. The restrictions imposed by the angular condition on the electromagnetic current operator of deuteron are discussed in detail. It is shown that the additive model for the current operator of interacting consistuencies is consistent with the angular condition only for the two first terms of expansion of the ''good'' electromagnetic current component jsub(+) in powers of the momentum transfer q. The RC into μsub(d) is calculated using the mattix element of the ''good'' component. The account of RC decreases essentially the discrepancy between the theoretical and experimental values. The value of Δsub(μ) is determined for the Hamada-Johnston potential hard core potential (0.93x10 -2 ) for the Reid soft core potential (0.71x10 -2 ) and for the Paris potential (0.63x10 -2 )
Charged point particles with magnetic moment in general relativity
International Nuclear Information System (INIS)
Amorim, R.; Tiomno, J.
1978-01-01
Halbwachs Lagrangean formalism for the theory of charged point particles with spin (g = 2) is generalized and formulated in General Relativity for particles of arbitrary charge and magnetic moment. Equations are obtained, both corresponding to Frenkel's condition S sub(μν) x sup(ν)=0 and to Nakano's condition S sub(μν) P sup(ν)=0. With the later condition the exact equations are highly coupled and non linear. When linearized in the electromagnetic and gravitational fields they coincide with de Groot-Suttorp equations for vanishing gravitational field and with Dixon-Wald equations in the absence of electromagnetic field. The equations corresponding to Frenkel's condition, when linearized in S sub(μν), coincide with Papapetrou's and Frenkel's equations in the corresponding limits [pt
Lifetimes and magnetic moments in odd-odd 70 As
International Nuclear Information System (INIS)
Pantelica, D.; Negoita, F.; Stanoiu, M.
1998-01-01
The extensive experimental and theoretical work on the structure of N∼Z, A = 60-80 nuclei revealed many interesting features: large prolate deformations (β = 0.4), strong shape variations as a function of particle number, excitation energy, spin and shape coexistence effects. They are related with drastic changes of properties observed in nuclei with Z≥33 when going from spherical nuclei with N = 50 to neutron deficient nuclei with N = 38 or 40. Both the rapid changes in structure and the shape coexistence appear to reflect the competition between the shell gaps which occur at large oblate and prolate deformations near nucleon numbers 36 and 38 for both protons and neutrons. For N∼Z nuclei the same shell gaps appear simultaneously for both protons and neutrons and reinforce each other. The microscopic structure of the nuclei in the mass region A = 60-80 is essentially determined by the 1g 9/2 , 2p 1/2 , 1f 5/2 and 2p 3/2 orbitals. Because no unique interpretation of the unusual features discovered in these nuclei exists, the systematic experimental study of structure of these nuclei is still an interesting subject. As part of a systematic experimental study undertaken to investigate the structure of neutron deficient, odd-odd As nuclei, 68,70,72 As, the level scheme of 70 As was investigated using heavy ion induced reactions and in-beam γ-ray spectroscopy techniques. At energies between 500 and 900 keV a multiplet of negative parity levels has been observed. At higher energies a high-spin positive parity sequence of levels starting with a E x = 1676 keV, J π 8 + level is strongly populated. Additional information is required in order to establish the structure of low and high-spin levels of both parities. The magnetic moments of the 8 + and 9 + levels have been measured using the time-integral perturbed angular distribution technique and the lifetimes of four levels have been determined using the recoil-distance method. From the measured lifetime for the 9
On the origin of the giant magnetic moment of the Al-Mn quasicrystals
Directory of Open Access Journals (Sweden)
Bocharov P.V.
2011-05-01
Full Text Available Ab initio calculations of magnetic moments for icosahedral clusters contained in crystal structures Al10Mn3, Al5Co2, Al17Mn4 (Al13Cr4Si4-type fulfilled in the framework of Density Functional Theory. The AlMn cluster having the trigonal D3h symmetry with the triangle of Mn ions in the interior has the moment being equal to three magnetic moments of a single manganese ion (4.4 μB, the moment of the tetrahedral Td cluster with the Mn tetrahedron in the interior is equal approximately to twelve magnetic moments of the single manganese ion (15.5 μB. The magnetic moment of icosahedral Al-Co clusters having the same configuration is equal to zero. The magnetic moments of the rod assembled from the icosahedral clusters with the sequence Td D3h - Td was found to be 20.5 μB. This value permits to explain the giant magnetic moment of icosahedral and decagonal Al-Mn quasicrystals and gives the indirect evidence to the hierarchical model of the quasicrystals structure proposed by the authors recently. An arrangement of magnetic moment carriers in the interior of the aluminum shell of icosahedral clusters permits to suggest the interaction between contacting manganese ions as the main origin of the giant magnetic moment of the Al-Mn quasicrystals.
Touchless attitude correction for satellite with constant magnetic moment
Ao, Hou-jun; Yang, Le-ping; Zhu, Yan-wei; Zhang, Yuan-wen; Huang, Huan
2017-09-01
Rescue of satellite with attitude fault is of great value. Satellite with improper injection attitude may lose contact with ground as the antenna points to the wrong direction, or encounter energy problems as solar arrays are not facing the sun. Improper uploaded command may set the attitude out of control, exemplified by Japanese Hitomi spacecraft. In engineering practice, traditional physical contact approaches have been applied, yet with a potential risk of collision and a lack of versatility since the mechanical systems are mission-specific. This paper puts forward a touchless attitude correction approach, in which three satellites are considered, one having constant dipole and two having magnetic coils to control attitude of the first. Particular correction configurations are designed and analyzed to maintain the target's orbit during the attitude correction process. A reference coordinate system is introduced to simplify the control process and avoid the singular value problem of Euler angles. Based on the spherical triangle basic relations, the accurate varying geomagnetic field is considered in the attitude dynamic mode. Sliding mode control method is utilized to design the correction law. Finally, numerical simulation is conducted to verify the theoretical derivation. It can be safely concluded that the no-contact attitude correction approach for the satellite with uniaxial constant magnetic moment is feasible and potentially applicable to on-orbit operations.
Observation of the Nuclear Magnetic Octupole Moment of 137Ba+
Hoffman, Matthew
Single trapped ions are ideal systems in which to test atomic physics at high precision, which can in turn be used for searches for violations of fundamental symmetries and physics beyond the standard model, in addition to quantum computation and a number of other applications. The ion is confined in ultra-high vacuum, is laser cooled to mK temperatures, and kept well isolated from the environment which allows these experimental efforts. In this thesis, a few diagnostic techniques will be discussed, covering a method to measure the linewidth of a narrowband laser in the presence of magnetic field noise, as well as a procedure to measure the ion's temperature using such a narrowband laser. This work has led to two precision experiments to measure atomic structure in 138Ba+, and 137Ba+ discussed here. First, employing laser and radio frequency spectroscopy techniques in 138Ba+, we measured the Lande- gJ factor of the 5D5/2 level at the part-per-million level, the highest precision to date. Later, the development of apparatus to efficiently trap and laser cool 137Ba+ has enabled a measurement of the hyperfine splittings of the 5D3/2 manifold, culminating in the observation of the nuclear magnetic octupole moment of 137Ba+.
Measurement of the zero-field magnetic dipole moment of magnetizable colloidal silica spheres
Claesson, E.M.; Erne, B.H.; Bakelaar, I.A.; Kuipers, B.W.M.; Philipse, A.P.
2007-01-01
The magnetic properties of dispersions of magnetic silica microspheres have been investigated by measuring the magnetization curves and the complex magnetic susceptibility as a function of frequency and field amplitude. The silica spheres appear to have a net permanent magnetic dipole moment, even
Tang, Cheng; Zhang, Teng; Weiss, David S.
2018-03-01
We explore ways to use the ability to measure the populations of individual magnetic sublevels to improve the sensitivity of magnetic field measurements and measurements of atomic electric dipole moments (EDMs). When atoms are initialized in the m =0 magnetic sublevel, the shot-noise-limited uncertainty of these measurements is 1 /√{2 F (F +1 ) } smaller than that of a Larmor precession measurement. When the populations in the even (or odd) magnetic sublevels are combined, we show that these measurements are independent of the tensor Stark shift and the second order Zeeman shift. We discuss the complicating effect of a transverse magnetic field and show that when the ratio of the tensor Stark shift to the transverse magnetic field is sufficiently large, an EDM measurement with atoms initialized in the superposition of the stretched states can reach the optimal sensitivity.
Correct use of the Gordon decomposition in the calculation of nucleon magnetic dipole moments
International Nuclear Information System (INIS)
Mekhfi, Mustapha
2008-01-01
We perform the calculation of the nucleon dipole magnetic moment in full detail using the Gordon decomposition of the free quark current. This calculation has become necessary because of frequent misuse of the Gordon decomposition by some authors in computing the nucleon dipole magnetic moment
The Measurement of the Muon's Anomalous Magnetic Moment Isn't
Feng, J L; Shadmi, Y; Feng, Jonathan L; Matchev, Konstantin T.; Shadmi, Yael
2003-01-01
Recently the Muon (g-2) Collaboration announced a new measurement of the muon's anomalous magnetic moment [hep-ex/0208001]. More precisely, however, what has been measured is the muon's anomalous spin precession frequency. We point out that this receives contributions from both the muon's anomalous magnetic and electric dipole moments, and the reported data and all existing constraints cannot distinguish between the two.
Spin moments, orbital moments and magnetic anisotropy of finite-length Co wires deposited on Pd(110)
Energy Technology Data Exchange (ETDEWEB)
Felix-Medina, R [Escuela de Ciencias FIsico-Matematicas, Universidad Autonoma de Sinaloa, Culiacan, Sinaloa (Mexico); Dorantes-Davila, J [Instituto de FIsica, Universidad Autonoma de San Luis PotosI, Alvaro Obregon 64, San Luis PotosI (Mexico); Pastor, G M [Laboratoire de Physique Quantique, Centre National de la Recherche Scientifique, Universite Paul Sabatier, Toulouse (France)
2002-12-01
The ground-state spin moments (S{sub z}), orbital moments (L{sub z}) and magnetic anisotropy energy (MAE) of Co{sub N} one-dimensional (1D) clusters (N{<=}12) deposited on the Pd(110) surface are determined in the framework of a self-consistent, real-space tight-binding method. Remarkably large total magnetic moments per Co atom, M{sub z}=(2(S{sub z})+(L{sub z}))/N=2.8-2.9 {mu}{sub B}, are obtained, which can be understood as the result of three physically distinct effects. The first and leading contribution is given by the local spin moments (S{sub iz}) at the Co atoms i=1, N (2(S{sub iz}){sub Co} {approx_equal}1.6 {mu}{sub B}). Second, significant spin moments are induced at the Pd atoms i > N close to the Co-Pd interface, which amount to about 25% of M{sub z} (2(S{sub iz}){sub Pd}=0.2-0.3 {mu}{sub B}). Finally, enhanced orbital magnetic moments (L{sub iz}) are responsible for approximately 20% of M{sub z}. In the case of the Co atoms, (L{sub iz}){sub Co}=0.28-0.33 {mu}{sub B} is almost a factor of three larger than the Co bulk orbital moment, while in Pd atoms (L{sub iz}){sub Pd}=0.05 {mu}{sub B} represents about 15% of the total local moment {mu}{sub iz}=2(S{sub iz})+(L{sub iz}). These results and the associated MAEs are analysed from a local perspective. The role of the cluster-surface interactions is discussed by comparison with the corresponding results for free-standing wires. Particularly in the case of monatomic 1D Co chains we observe that the lowest-energy magnetization direction (easy axis) changes from in line to off plane upon deposition on Pd(110). Wire-substrate hybridizations are therefore crucial for the magneto-anisotropic behaviour of 1D magnetic nanostructures on metallic substrates.
Development of magnetic moments in Fe1 - xNix-alloys
Glaubitz, Benjamin; Buschhorn, Stefan; Brüssing, Frank; Abrudan, Radu; Zabel, Hartmut
2011-06-01
We have investigated the magnetic properties of Fe1 - xNix-alloys for 13 different compositions ranging from pure Fe to pure Ni. The alloy series was prepared as thin films by co-deposition of Fe and Ni via ultra-high vacuum magnetron sputtering and the concentrations were determined by energy dispersive x-ray fluorescence analysis (EDX). The averaged magnetization and magnetic moment were measured at room temperature using a superconducting quantum interference device (SQUID) magnetometer and a vibrating sample magnetometer (VSM). Making use of x-ray magnetic circular dichroism (XMCD), the individual magnetic moments of Fe and Ni across the alloy concentration range were analyzed; thus their spin and orbital contributions were extracted. The weighted sum of the individual moments agrees very well with the average moments determined via SQUID and VSM. The Ni moment steadily increases from the pure Ni towards to the pure Fe range, while the Fe moment scatters around a value of about 2.4 µB. Close to the invar composition of x = 0.35 we do not observe an anomaly of the magnetic moments, either of the individual moments or of the average moment. We also discuss different assumptions for the analysis of the XMCD spectra and assess the results in the light of recent theoretical predictions and literature values.
Development of magnetic moments in Fe{sub 1-x}Ni{sub x}-alloys
Energy Technology Data Exchange (ETDEWEB)
Glaubitz, Benjamin; Buschhorn, Stefan; Bruessing, Frank; Abrudan, Radu; Zabel, Hartmut [Institut fuer Experimentalphysik/Festkoerperphysik, Ruhr-Universitaet Bochum, 44780 Bochum (Germany)
2011-06-29
We have investigated the magnetic properties of Fe{sub 1-x}Ni{sub x}-alloys for 13 different compositions ranging from pure Fe to pure Ni. The alloy series was prepared as thin films by co-deposition of Fe and Ni via ultra-high vacuum magnetron sputtering and the concentrations were determined by energy dispersive x-ray fluorescence analysis (EDX). The averaged magnetization and magnetic moment were measured at room temperature using a superconducting quantum interference device (SQUID) magnetometer and a vibrating sample magnetometer (VSM). Making use of x-ray magnetic circular dichroism (XMCD), the individual magnetic moments of Fe and Ni across the alloy concentration range were analyzed; thus their spin and orbital contributions were extracted. The weighted sum of the individual moments agrees very well with the average moments determined via SQUID and VSM. The Ni moment steadily increases from the pure Ni towards to the pure Fe range, while the Fe moment scatters around a value of about 2.4 {mu}{sub B}. Close to the invar composition of x = 0.35 we do not observe an anomaly of the magnetic moments, either of the individual moments or of the average moment. We also discuss different assumptions for the analysis of the XMCD spectra and assess the results in the light of recent theoretical predictions and literature values.
A fluxonium-based artificial molecule with a tunable magnetic moment
Kou, A.; Smith, W. C.; Vool, U.; Brierley, R. T.; Meier, H.; Frunzio, L.; Girvin, S. M.; Glazman, L. I.; Devoret, M. H.
We have designed and measured an engineered artificial molecule, composed of two strongly coupled fluxonium atoms, which possesses a tunable magnetic moment. An externally applied magnetic flux tunes the molecule between two regimes: one in which the ground-excited state manifold has a magnetic dipole moment and one in which the ground-excited state manifold has only a magnetic quadrupole moment. By varying the applied external flux, we find the coherence of the molecule to be limited by local flux noise. Work supported by: ARO, ONR, NSF, AFOSR, and YINQE.
Measurement of Short Living Baryon Magnetic Moment using Bent Crystals at SPS and LHC
Burmistrov, L; Ivanov, Yu; Massacrier, L; Robbe, P; Scandale, W; Stocchi, A
2016-01-01
The magnetic moments of baryons containing u,d and s quarks have been extensively studied and measured. The experimental results are all obtained by a well-assessed method that consists in measuring the polarisation vector of the incoming particles and the precession angle when the particle is travelling through an intense magnetic field. The polarization is evaluated by analysing the angular distribution of the decay products. No measurement of magnetic moments of charm or beauty baryons (and τ leptons) has been performed so far. The main reason is the lifetimes of charm/beauty baryons, too short to measure the magnetic moment by standard techniques. Historically, the prediction of baryon magnetic moments was one of the striking successes of the quark model. The importance of the measurement of heavy quark magnetic moment is to test the possibility that the charmed and/or beauty quarks has an anomalous magnetic moment, arising if those quarks are composite objects. Measurements on magnetic moments of heav...
Detecting the neutrino magnetic moment at hadron colliders
Boyarkin, O. M.; Boyarkina, G. G.
2014-11-01
We consider the model based on the S U (2 )R×S U (2 )L×U (1 )B -L gauge group with Majorana neutrinos. In this model the transit dipole magnetic moment (μν N)if which is associated with the Ni→νfγ transition may be as large as a few×1 0-8μB . The possible manifestations of the (μν N)if at hadron colliders are investigated. In doing so, we assume that one of the three heavy right-handed neutrinos Ne R is on the electroweak scale. The process of Ne R production p +p →WR-→e-Ne R, with the subsequent Ne R decay through the channel Ne R→νe L+γ , is investigated. Problems caused by selecting the signal from background is examined. It is shown that the process in question is the most perspective one for detecting the (μν N)if, provided the condition mWRThe cross section of Nμ R production under the collision of a high-energy light neutrino beam with the proton target νμ L+p →γ →Nμ R+p +X is investigated. The produced Nμ R neutrino is identified through the decay channel Nμ R→μ±+2 j . Detection of both the positive and negative charged muons will point to the Majorana nature of the neutrino. On the other hand, detection of the right-handed polarized muons will be unambiguously indicative of a nonzero value of (μν N)if.
Vališka, Michal; Klicpera, Milan; Doležal, Petr; Fabelo, Oscar; Stunault, Anne; Diviš, Martin; Sechovský, Vladimír
2018-03-01
In a cubic ferromagnet, small spontaneous lattice distortions are expected below the Curie temperature, but the phenomenon is usually neglected. This study focuses on such an effect in the U4Ru7Ge6 compound. Based on DFT calculations, we propose a lattice distortion from the cubic I m -3 m space group to a lower, rhombohedral, symmetry described by the R -3 m space group. The strong spin-orbit coupling of the uranium ions plays an essential role in lowering the symmetry, giving rise to two different U sites (U1 and U2). Using polarized neutron diffraction in applied magnetic fields of 1 and 9 T in the ordered state (1.9 K ) and in the paramagnetic state (20 K ), we bring convincing experimental evidence of this splitting of the U sites, with different magnetic moments. The data have been analyzed both by maximum entropy calculations and by a direct fit in the dipolar approximation. In the ordered phase, the μL/μS ratio of the orbital and spin moments on the U2 site is remarkably lower than for the free U3 + or U4 + ion, which points to a strong hybridization of the U 5 f wave functions with the 4 d wave functions of the surrounding Ru. On the U1 site, the μL/μS ratio exhibits an unexpectedly low value: the orbital moment is almost quenched, like in metallic α -uranium. As a further evidence of the 5 f -4 d hybridization in the U4Ru7Ge6 system, we observe the absence of a magnetic moment on the Ru1 site, but a rather large induced moment on the Ru2 site, which is in closer coordination with both U positions. Very similar results are obtained at 20 K in the ferromagnetic regime induced by the magnetic field of 9 T . This shows that applying a strong magnetic field above the Curie temperature also leads to the splitting of the uranium sites, which further demonstrates the intimate coupling of the magnetic ordering and structural distortion. We propose that the difference between the magnetic moment on the U1 and U2 sites results from the strong spin
Directory of Open Access Journals (Sweden)
Felix Tobias Kurz
2016-12-01
Full Text Available In biological tissue, an accumulation of similarly shaped objects with a susceptibility difference to the surrounding tissue generates a local distortion of the external magnetic field in magnetic resonance imaging. It induces stochastic field fluctuations that characteristically influence proton spin diffusion in the vicinity of these magnetic perturbers. The magnetic field correlation that is associated with such local magnetic field inhomogeneities can be expressed in the form of a dynamic frequency autocorrelation function that is related to the time evolution of the measured magnetization. Here, an eigenfunction expansion for two simple magnetic perturber shapes, that of spheres and cylinders, is considered for restricted spin diffusion in a simple model geometry. Then, the concept of generalized moment analysis, an approximation technique that is applied in the study of (non-reactive processes that involve Brownian motion, allows to provide analytical expressions for the correlation function for different exponential decay forms. Results for the biexponential decay for both spherical and cylindrical magnetized objects are derived and compared with the frequently used (less accurate monoexponential decay forms. They are in asymptotic agreement with the numerically exact value of the correlation function for long and short times.
Tunability of Size and Magnetic Moment of Iron Oxide Nanoparticles Synthesized by Forced Hydrolysis
Directory of Open Access Journals (Sweden)
Ben Sutens
2016-07-01
Full Text Available To utilize iron oxide nanoparticles in biomedical applications, a sufficient magnetic moment is crucial. Since this magnetic moment is directly proportional to the size of the superparamagnetic nanoparticles, synthesis methods of superparamagnetic iron oxide nanoparticles with tunable size are desirable. However, most existing protocols are plagued by several drawbacks. Presented here is a one-pot synthesis method resulting in monodisperse superparamagnetic iron oxide nanoparticles with a controllable size and magnetic moment using cost-effective reagents. The obtained nanoparticles were thoroughly characterized by transmission electron microscopy (TEM, X-ray diffraction (XRD and Fourier transform infrared (FT-IR measurements. Furthermore, the influence of the size on the magnetic moment of the nanoparticles is analyzed by superconducting quantum interference device (SQUID magnetometry. To emphasize the potential use in biomedical applications, magnetic heating experiments were performed.
The effect of a neutrino magnetic moment on nuclear excitation processes
International Nuclear Information System (INIS)
Dodd, A.C.; Papageorgiu, E.; Ranfone, S.
1991-01-01
It is shown that the MeV-range neutrinos with a magnetic moment of ≅ 10 -11 Bohr magnetons would excite nuclei, like 12 C, with cross sections comparable to those obtained in the Standard Model. This implies the possibility of improving the present experimental bounds on the magnetic moment of any flavour of neutrinos by one order of magnitude. Such a magnetic moment would also enhance the coherent neutrino-nuclear scattering in low-temperature detectors, enabling them to set comparable limits. (author)
Constraining neutrino magnetic moment with solar and reactor neutrino data
Tortola, M. A.
2004-01-01
We use solar neutrino data to derive stringent bounds on Majorana neutrino transition moments (TMs). Such moments, if present, would contribute to the neutrino-electron scattering cross section and hence alter the signal observed in Super-Kamiokande. Using the latest solar neutrino data, combined with the results of the reactor experiment KamLAND, we perform a simultaneous fit of the oscillation parameters and TMs. Furthermore, we include data from the reactor experiments Rovno, TEXONO and MU...
X-ray detection of transient magnetic moments induced by a spin current in Cu
Energy Technology Data Exchange (ETDEWEB)
Kukreja, R. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); Bonetti, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); Chen, Z. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); Backes, D. [New York Univ. (NYU), New York, NY (United States); Acremann, Y. [ETH Zurich, Zurich (Switzerland); Katine, J. [HGST, a Western Digital Company, San Jose, CA (United States); Kent, A. D. [New York Univ. (NYU), New York, NY (United States); Durr, H. A. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Ohldag, H. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stohr, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States)
2015-08-24
We have used a MHz lock-in x-ray spectromicroscopy technique to directly detect changes in magnetic moment of Cu due to spin injection from an adjacent Co layer. The elemental and chemical specificity of x rays allows us to distinguish two spin current induced effects. We detect the creation of transient magnetic moments of 3×10^{–5}_{μB} on Cu atoms within the bulk of the 28 nm thick Cu film due to spin accumulation. The moment value is compared to predictions by Mott’s two current model. We also observe that the hybridization induced existing magnetic moments at the Cu interface atoms are transiently increased by about 10% or 4×10^{–3}_{μB} per atom. As a result, this reveals the dominance of spin-torque alignment over Joule heat induced disorder of the interfacial Cu moments during current flow.
Planar Hall ring sensor for ultra-low magnetic moment sensing
DEFF Research Database (Denmark)
Hung, Tran Quang; Terki, Ferial; Kamara, Souleymanne
2015-01-01
The field sensitivity of a planar Hall effect (PHE) micro-ring type biosensor has been investigated as a function of magnetizing angle of the sensor material, for the sensing of low magnetic moment superparamagnetic labels. The field sensitivity is maximal at a magnetizing angle of α = 20°. At th...
Core Polarization and Tensor Coupling Effects on Magnetic Moments of Hypernuclei
International Nuclear Information System (INIS)
Jiang-Ming, Yao; Jie, Meng; Hong-Feng, Lü; Greg, Hillhouse
2008-01-01
Effects of core polarization and tensor coupling on the magnetic moments in Λ 13 C, Λ 17 O, and Λ 41 Ca Λ-hypernuclei are studied by employing the Dirac equation with scalar, vector and tensor potentials. It is found that the effect of core polarization on the magnetic moments is suppressed by Λ tensor coupling. The Λ tensor potential reduces the spin-orbit splitting of p Λ states considerably. However, almost the same magnetic moments are obtained using the hyperon wavefunction obtained via the Dirac equation either with or without the A tensor potential in the electromagnetic current vertex. The deviations of magnetic moments for p Λ states from the Schmidt values are found to increase with nuclear mass number. (nuclear physics)
The magnetic moment of NiO nanoparticles determined by Mössbauer spectroscopy
DEFF Research Database (Denmark)
Bahl, Christian Robert Haffenden; Hansen, Mikkel Fougt; Pedersen, Thomas
2006-01-01
is in accordance with a model based on random occupation of surface sites. The analyses of the magnetization data gave larger magnetic moments, but the difference can be explained by the different sensitivity of the two methods to a particle size distribution and by interactions between the particles, which may...... electron microscopy and x-ray diffraction and found to be plate-shaped. Computer simulations showed that high-field Mössbauer data are very sensitive to the size of the uncompensated magnetic moment. From analyses of the Mössbauer spectra we have estimated that the size of the uncompensated magnetic moment......We have studied the magnetic properties of 57Fe-doped NiO nanoparticles using Mössbauer spectroscopy and magnetization measurements. Two samples with different degrees of interparticle interaction were studied. In both samples the particles were characterized by high-resolution transmission...
Statistical thermodynamics and magnetic moments of Landau quantized group VI dichalcogenides
Horing, Norman J. M.
2018-02-01
This work is focused on the determination of the Helmholtz free energy and the magnetic moments of the ‘Dirac-like’ group VI dichalcogenides subject to Landau quantization. We employ a technique described by Wilson to relate the free energy to the Green’s function for the dichalcogenides in a high magnetic field, which was recently evaluated explicitly in terms of elementary functions. In the course of this analysis, the partition function is determined as a function of the magnetic field as well. The results exhibit the role of the quantizing magnetic field in the Helmholtz free energy at arbitrary temperature, and they are also employed to obtain the magnetic moments of the dichalcogenides. Explicit analytic formulas characteristic of de Haas–van Alphen oscillatory phenomenology are presented in the degenerate limit, and nondegenerate Landau quantization effects are also presented for the dichalcogenide magnetic moments.
Fluorine-induced local magnetic moment in graphene: A hybrid DFT study
Kim, Hyun-Jung; Cho, Jun-Hyung
2013-01-01
Recent experimental evidence that fluorinated graphene creates local magnetic moments around F adatoms has not been supported by semilocal density-functional theory (DFT) calculations where the adsorption of an isolated F adatom induces no magnetic moment in graphene. Here, we show that such an incorrect prediction of the nonmagnetic ground state is due to the self-interaction error inherent in semilocal exchange-correlation functionals. The present hybrid DFT calculation for an isolated F ad...
Effects of the magnetic dipole moment of charged vector mesons in their radiative decay distribution
International Nuclear Information System (INIS)
Castro, G.L.; Sanchez, G.T.
1997-01-01
We consider the effects of anomalous magnetic dipole moments of vector mesons in the decay distribution of photons emitted in two-pseudoscalar decays of charged vector mesons. By choosing a kinematical configuration appropriate to isolate these effects from model-dependent and dominant bremsstrahlung contributions, we show that this method can provide a valid alternative for a measurement of the unknown magnetic dipole moments of charged vector mesons. copyright 1997 The American Physical Society
Calculation of the electron magnetic moment in Fried-Yennie-gauge QED
International Nuclear Information System (INIS)
Adkins, G.S.
1989-01-01
The two-loop contribution to the electron magnetic moment is calculated in the Fried-Yennie gauge. This is the first treatment of the magnetic moment beyond one-loop order in a gauge other than the Feynman gauge. The Fried-Yennie gauge is infrared safe, and the calculation is done without introducing an infrared cutoff or photon mass. The Fried-Yennie-gauge result agrees with the Feynman-gauge result, as expected
Magnetization, magnetic susceptibility, effective magnetic moment of Fe3+ ions in Bi25FeO39 ferrite
International Nuclear Information System (INIS)
Zatsiupa, A.A.; Bashkirov, L.A.; Troyanchuk, I.O.; Petrov, G.S.; Galyas, A.I.; Lobanovsky, L.S.; Truhanov, S.V.
2014-01-01
Magnetic susceptibility for ferrite Bi 25 FeO 39 is measured at 5–950 K in the magnetic field of 0.86 T. It is shown that Bi 25 FeO 39 is paramagnetic in the temperature range 5−950 K. The saturation magnetization is equal to 5.04μ B per formula unit at 5 K in a magnetic field of 10 T. It is found that at 5−300 K the effective magnetic moment of Fe 3+ ions in Bi 25 FeO 39 is equal to 5.82μ B . - Graphical abstract: The dependence of the magnetization (n, μ B ) on the magnetic field for one formula unit of Bi 25 FeO 39 at 5 K. - Highlights: • Magnetic susceptibility for Bi 25 FeO 39 is measured at 5–950 K in the magnetic field of 0.86 T. • It is shown that Bi 25 FeO 39 is paramagnetic in the temperature range 5−950 K. • The saturation magnetization is equal to 5.04μ B per formula unit at 5 K in a magnetic field of 10 T
Two dimensional electron gas confined over a spherical surface: Magnetic moment
Energy Technology Data Exchange (ETDEWEB)
Hernando, A; Crespo, P [Instituto de Magnetismo Aplicado, UCM-CSIC-ADIF, Las Rozas. P. O. Box 155, Madrid 28230 (Spain) and Dpto. Fisica de Materiales, Universidad Complutense (Spain); Garcia, M A, E-mail: antonio.hernando@adif.es [Instituto de Ceramica y Vidrio, CSIC c/Kelsen, 5 Madrid 28049 (Spain)
2011-04-01
Magnetism of capped nanoparticles, NPs, of non-magnetic substances as Au and ZnO is briefly reviewed. The source of the magnetization is discussed on the light of recent X-ray magnetic circular dichroism experiments. As magnetic dichroism analysis has pointed out impurity atoms bonded to the surface act as donor or acceptor of electrons that occupy the surface states. It is proposed that mesoscopic collective orbital magnetic moments induced at the surface states can account for the experimental magnetism characteristic of these nanoparticles. The total magnetic moment of the surface originated at the unfilled Fermi level can reach values as large as 10{sup 2} or 10{sup 3} Bohr magnetons.
Neutral fermion possessing by electric and magnetic moments in external electromagnetic field
International Nuclear Information System (INIS)
Khalilov, V.R.
2001-01-01
It is shown that in 2+1 dimensions the Dirac equations for a neutral fermion, specified by electric and magnetic dipole moments, is reduced in the electromagnetic field to the Dirac equation for the charged fermion in the external field, characterized by some pseudovector potential. The neutral fermion charge is determined by its dipole moments. The exact solution is found for the Dirac equation for the massive neutral fermion with magnetic and electric dipole moments in the external electromagnetic plane-wave field. The problem on the neutral fermion vacuum polarization in presence of external electromagnetic fields is considered [ru
Antonelli, V; Picariello, M; Pulido, J; Torrente-Lujan, E
2003-01-01
We present here a recopilation of recent results about the possibility of detecting solar electron antineutrinos produced by solar core and convective magnetic fields. These antineutrinos are predicted by spin-flavor oscillations at a significant rate even if this mechanism is not the leading solution to the SNP. Using the recent Kamland results and assuming a concrete model for antineutrino production by spin-flavor precession in the convective zone based on chaotic magnetic fields,we obtain bounds on the flux of solar antineutrinos, on the average conversion neutrino-antineutrino probability and on intrinsic neutrino magnetic moment. In the most conservative case, $\\mu\\lsim 2.5\\times 10^{-11} \\mu_B$ (95% CL). When studying the effects of a core magnetic field, we find in the weak limit a scaling of the antineutrino probability with respect to the magnetic field profile in the sense that the same probability function can be reproduced by any profile with a suitable peak field value. In this way the solar ele...
Light-by-light scattering and muon's anomalous magnetic moment
International Nuclear Information System (INIS)
Pauk, Vladyslav
2014-01-01
phenomenological implications of these results for mesons in both the light-quark sector and the charm-quark sector. In the second part of this thesis we develop the formalism to provide an improved estimate for the hadronic light-by-light (HLbL) correction to the muon's anomalous magnetic moment a μ , by considering single meson contributions beyond the leading pseudo-scalar mesons. This is motivated by the present 3σ deviation between the measurement of a μ and its estimate in the Standard Model. Furthermore, a forthcoming new experiment at Fermilab aims to improve the experimental precision by a factor of 4 which also requires a similar theoretical improvement. We incorporate available experimental input as well as constraints from light-by-light scattering sum rules to estimate the effects of axial-vector, scalar, and tensor mesons. We give numerical evaluations for the HLbL contribution of these states to a μ . The presented formalism allows to further improve on these estimates, once new data for such meson states will become available. In the last part of this work, we present a new dispersion formalism developed for the HLbL contribution to a μ and test the formalism for the case of scalar field theory. The new framework opens a unique possibility for a consistent incorporation of data from e + e - colliders for single- as well as multi-meson contributions. Furthermore, it allows to systematically control the HLbL uncertainty in the a μ which is a crucial step in searches of new physics using this precision quantity.
International Nuclear Information System (INIS)
Gisin, B V
2002-01-01
We consider the anomalous magnetic moment from an 'optical viewpoint' using an analogy between the motion of a particle with a magnetic moment in a magnetic field and the propagation of an optical pulse through an electro-optical crystal in an electric field. We show that an optical experiment similar to electron magnetic resonance is possible in some electro-optical crystals possessing the Faraday effect. This phenomenon is described by an analogue of the Pauli equation extracted from the Maxwell equation in the slowly varied amplitude approximation. In such an experiment the modulation by rotating fields plays a significant role. From the optical viewpoint the modulation assumes introducing the concept of a point rotation frame with the rotation axis at every point originated from the concept of the optical indicatrix (index ellipsoid). We discuss the connection between the non-classical transformation by transition from one such frame to another and an anomalous magnetic moment
Spontaneous intracranial hypotension syndrome: magnetic resonance findings in two patients
International Nuclear Information System (INIS)
Ortega, R.; Pastor, J.; Escamilla, F.; Romero, M. I.
1999-01-01
The postural headache syndrome associated with a decrease in the cerebrospinal fluid (CSF) pressure is generally secondary to the CSF leakage that usually occurs after diagnostic lumbar puncture. Spontaneous intracranial hypotension can not be attributed to any known cause or previous diagnostic or therapeutic intervention. The syndrome is characterized by severe headache that is relieved by lying supine. During lumbar puncture, the CSF pressure is normally low. We present two patients in whom gadolinium-enhanced magnetic resonance imaging showed widespread thickening and enhancement of the dura mater and subdural fluid collections. (Author) 13 refs
Magnetic moment jumps in flat and nanopatterned Nb thin-walled cylinders
Energy Technology Data Exchange (ETDEWEB)
Tsindlekht, M.I., E-mail: mtsindl@vms.huji.ac.il [The Racah Institute of Physics, The Hebrew University of Jerusalem, 91904 Jerusalem (Israel); Genkin, V.M.; Felner, I.; Zeides, F.; Katz, N. [The Racah Institute of Physics, The Hebrew University of Jerusalem, 91904 Jerusalem (Israel); Gazi, Š.; Chromik, Š. [The Institute of Electrical Engineering SAS, Dúbravská cesta 9, 84104 Bratislava (Slovakia); Dobrovolskiy, O.V. [Physikalisches Institut, Goethe University, 60438 Frankfurt am Main (Germany); Physics Department, V. Karazin Kharkiv National University, 61077 Kharkiv (Ukraine); Sachser, R.; Huth, M. [Physikalisches Institut, Goethe University, 60438 Frankfurt am Main (Germany)
2017-02-15
Highlights: • Magnetization curves of as-prepared and patterned thin-walled cylinders were measured in magnetic fields applied parallel to cylinders axis. • Magnetic moment jumps were observed in magnetic fields lower and above Hc1. • Critical current density in isthmus between two antidots is higher than in a film itself. - Abstract: Penetration of magnetic flux into hollow superconducting cylinders is investigated by magnetic moment measurements. The magnetization curves of a flat and a nanopatterned thin-walled superconducting Nb cylinders with a rectangular cross section are reported for the axial field geometry. In the nanopatterned sample, a row of micron-sized antidots (holes) was milled in the film along the cylinder axis. Magnetic moment jumps are observed for both samples at low temperatures for magnetic fields not only above H{sub c1}, but also in fields lower than H{sub c1}, i. e., in the vortex-free regime. The positions of the jumps are not reproducible and they change from one experiment to another, resembling vortex lattice instabilities usually observed for magnetic fields larger than H{sub c1}. At temperatures above 0.66T{sub c} and 0.78T{sub c} the magnetization curves become smooth for the patterned and the as-prepared sample, respectively. The magnetization curve of a reference flat Nb film in the parallel field geometry does not exhibit jumps in the entire range of accessible temperatures.
Direct high-precision measurement of the magnetic moment of the proton.
Mooser, A; Ulmer, S; Blaum, K; Franke, K; Kracke, H; Leiteritz, C; Quint, W; Rodegheri, C C; Smorra, C; Walz, J
2014-05-29
One of the fundamental properties of the proton is its magnetic moment, µp. So far µp has been measured only indirectly, by analysing the spectrum of an atomic hydrogen maser in a magnetic field. Here we report the direct high-precision measurement of the magnetic moment of a single proton using the double Penning-trap technique. We drive proton-spin quantum jumps by a magnetic radio-frequency field in a Penning trap with a homogeneous magnetic field. The induced spin transitions are detected in a second trap with a strong superimposed magnetic inhomogeneity. This enables the measurement of the spin-flip probability as a function of the drive frequency. In each measurement the proton's cyclotron frequency is used to determine the magnetic field of the trap. From the normalized resonance curve, we extract the particle's magnetic moment in terms of the nuclear magneton: μp = 2.792847350(9)μN. This measurement outperforms previous Penning-trap measurements in terms of precision by a factor of about 760. It improves the precision of the forty-year-old indirect measurement, in which significant theoretical bound state corrections were required to obtain µp, by a factor of 3. By application of this method to the antiproton magnetic moment, the fractional precision of the recently reported value can be improved by a factor of at least 1,000. Combined with the present result, this will provide a stringent test of matter/antimatter symmetry with baryons.
Nuclear structure studies by means of magnetic moments of excited states
International Nuclear Information System (INIS)
Kaeubler, L.; Prade, H.; Schneider, L.; Brinckmann, H.F.; Stary, F.
1981-09-01
Experimental arrangements installed at the cyclotron U-120 and the tandem accelerator EGP-10 for the in-beam measurement of magnetic moments of excited nuclear states are discribed. The Perturbed-Angular-Distribution-method (PAD) has been used. A new evaluation method has been developed for the unique determination of the Larmor frequency from spin-procession spectra R(t) with less than half of an oscillation period between consecutive particle pulses. Magnetic moments in transitional nuclei or in nuclei near closed shells ( 103 Pd, 105 Ag, 117 Sb, 117 Te, 121 Te, 121 I, 143 Pm and 207 Bi) were measured. The results are discussed with the aim to get information about the nuclear structure of the corresponding isomeric states in connection with complex spectroscopic investigations. Therefore, the experimental values are compared to the results of model calculations (core-polarization, core-particle-coupling, Nilsson, particle-rotation-coupling or shell-model) or to the estimates on the basis of the additivity of effective magnetic moments. Single-particle aspects are discussed in connection with the magnetic moments of hsub(11/2)-, dsub(5/2)- and gsub(7/2)-neutron (ν) and proton (π) states in the nuclei 103 Pd, 117 Te, 121 Te and 143 Pm, respectively. The configurations of (π) 3 and (π)(ν) 2 -three-particle states in 105 Ag, 117 Sb, 121 I and 207 Bi could be determined using the additivity rule. The experimental magnetic moments of states in 143 Pm agree very well with the results of shell-model calculations, which have firstly been carried out also for negative-parity states in this mass region. Considering magnetic moments in 117 Te and 121 Te we could demonstrate the influence of different nuclear deformations on the magnetic moments in transitional nuclei. (author)
Kopferman, H; Massey, H S W
1958-01-01
Nuclear Moments focuses on the processes, methodologies, reactions, and transformations of molecules and atoms, including magnetic resonance and nuclear moments. The book first offers information on nuclear moments in free atoms and molecules, including theoretical foundations of hyperfine structure, isotope shift, spectra of diatomic molecules, and vector model of molecules. The manuscript then takes a look at nuclear moments in liquids and crystals. Discussions focus on nuclear paramagnetic and magnetic resonance and nuclear quadrupole resonance. The text discusses nuclear moments and nucl
Spontaneous current sheets in magnetic fields with applications to stellar X-rays
Parker, Eugene N
1994-01-01
Expanding upon the ideas first proposed in his seminal book Cosmical Magnetic Fields, Eugene N. Parker here offers the first in-depth treatment of the magnetohydrodynamic theory of spontaneous magnetic discontinuities. In detailing his theory of the spontaneous formation of tangential discontinuities (current sheets) in a magnetic field embedded in highly conducting plasma, Parker shows how it can be used to explain the activity of the external magnetic fields of planets, stars, interstellar gas clouds, and galaxies, as well as the magnetic fields in laboratory plasmas. Provocative and fascinating, Spontaneous Current Sheets in Magnetic Fields presents a bold new theory that will excite interest and discussion throughout the space physics community.
EM Induction Experiment to Determine the Moment of a Magnet
Najiya Maryam, K. M.
2014-01-01
If we drop a magnet through a coil, an emf is induced in the coil according to Faraday's law of electromagnetic induction. Here, such an experiment is done using expEYES kit. The plot of emf versus time has a specific shape with two peaks. A theoretical analysis of this graph is discussed here for both short and long cylindrical magnets.…
Phase formation, thermal stability and magnetic moment of cobalt nitride thin films
Directory of Open Access Journals (Sweden)
Rachana Gupta
2015-09-01
Full Text Available Cobalt nitride (Co-N thin films prepared using a reactive magnetron sputtering process are studied in this work. During the thin film deposition process, the relative nitrogen gas flow (RN2 was varied. As RN2 increases, Co(N, Co4N, Co3N and CoN phases are formed. An incremental increase in RN2, after emergence of Co4N phase at RN2 = 10%, results in a linear increase of the lattice constant (a of Co4N. For RN2 = 30%, a maximizes and becomes comparable to its theoretical value. An expansion in a of Co4N, results in an enhancement of the magnetic moment, to the extent that it becomes even larger than pure Co. Such larger than pure metal magnetic moment for tetra-metal nitrides (M4N have been theoretically predicted. Incorporation of N atoms in M4N configuration results in an expansion of a (relative to pure metal and enhances the itinerary of conduction band electrons leading to larger than pure metal magnetic moment for M4N compounds. Though a higher (than pure Fe magnetic moment for Fe4N thin films has been evidenced experimentally, higher (than pure Co magnetic moment is evidenced in this work.
Compositeness Effects in the Anomalous Weak-Magnetic Moment of Leptons
González-Garciá, M Concepción
1996-01-01
We investigate the effects induced by excited leptons, at the one-loop level, in the anomalous magnetic and weak-magnetic form factors of the leptons. Using a general effective Lagrangian approach to describe the couplings of the excited leptons, we compute their contributions to the weak-magnetic moment of the $\\tau$ lepton, which can be measured on the $Z$ peak, and we compare it with the contributions to $g_\\mu - 2$, measured at low energies.
Spin magnetic moments from single atoms to small Cr clusters
Energy Technology Data Exchange (ETDEWEB)
Boeglin, C.; Decker, R.; Bulou, H.; Scheurer, F.; Chado, I. [IPCMS-GSI - UMR 7504, 67037 Strasbourg Cedex (France); Ohresser, P. [LURE, 91405 Orsay (France); Dhesi, S.S. [ESRF, BP 220, 38043 Grenoble Cedex (France); Present permanent address: Diamond Light Source, Chilton, Didcot OX11 0QX (United Kingdom); Gaudry, E. [LMCP, 4, place Jussieu, 75252 Paris (France); Lazarovits, B. [CCMS, T.U. Vienna, Gumpendorfstr. 1a, 1060 Wien (Austria)
2005-07-01
Morphology studies at the first stages of the growth of Cr/Au(111) are reported and compared to the magnetic properties of the nanostructures. We analyze by Scanning Tunneling Microscopy and Low Energy Electron Diffraction the Cr clusters growth between 200 K and 300 K. In the early stages of the growth the morphology of the clusters shows monoatomic high islands located at the kinks of the herringbone reconstructed Au(111) surface. By X-ray Magnetic Circular Dichroism performed on the Cr L{sub 2,3} edges it is shown that the temperature dependent morphology strongly influences the magnetic properties of the Cr clusters. We show that in the sub-monolayer regime Cr clusters are antiferromagnetic and paramagnetic when the size reaches the atomic limit. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
Unusual temperature dependence of the magnetic moment in URu2Si2
International Nuclear Information System (INIS)
Faak, B.; Flouquet, J.; Lejay, P.
1994-01-01
The influence of the sample quality on the magnetic properties of the heavy-fermion superconductor URu 2 Si 2 has been studied by elastic neutron scattering. Two single crystals prepared under identical conditions received different heat treatments. The as-grown crystal shows an unusual temperature dependence of the magnetic Bragg peak intensity. The annealed sample behaves normally. The low-temperature magnetic moment is identical for the two samples, showing that the small moment of 0.023 (3) μ B is intrinsic. By varying the instrumental resolution, we show that the ordered moment as well as the limited correlation length (200-400 A) are of static origin. The finite correlation length appears related to defects. (author). 9 refs., 1 fig
Nuclear structure and magnetic moment of the unstable 12B-12N mirror pair
International Nuclear Information System (INIS)
Zheng Yongnan; Zhou Dongmei; Yuan Daqing; Zuo Yi; Fan Ping; Xu Yongjun; Zhu Jiazheng; Wang Zhiqiang; Luo Hailong; Zhang Xizhen; Zhu Shengyun; Mihara, M.; Matsuta, K.; Fukuda, M.; Minamisono, T.; Suzuki, T.
2010-01-01
Magnetic moments of the A=12 unstable mirror pair nuclides 12 B and 12 N have been measured by the β-NMR technique. The experimentally measured magnetic moments are μ( 12 B)=1.00(17)μ N and μ( 12 N)=0.4571(1)μ N . The improved shell model using an SFO Hamiltonian with enhanced spin-isospin monopole proton-neutron interaction and modified single-particle energies is employed to calculate the magnetic moments of 12 B and 12 N. The calculation yields μ( 12 B)=0.929μ N and μ( 12 N)=0.452μ N and has produced a new magic number 6 for the short-lived unstable mirror pair nuclides 12 B and 12 N. (authors)
Forces on a current loop and magnetic moment
International Nuclear Information System (INIS)
Corbo, Guido
2010-01-01
We compute the action of a static magnetic field on a current loop. From this we recover the definition of m as given in textbooks. The presentation is accessible to undergraduate students with a knowledge of the basic notions of classical electromagnetism. (letters and comments)
Magnetic moment measurement of 140Ba nuclei using transient field technique
International Nuclear Information System (INIS)
Saxena, Mansi; Mandal, S.; Siwal, Davinder; Rainovski, G.; Danchev, M.; Damyanova, A.; Gladnishki, K.; Leske, J.; Bauer, C.; Bloch, T.; John, P.; Pietralla, N.; Wollersheim, H.J.; Kojouharov, I.; Pietri, S.; Schaffner, H.
2011-01-01
Mixed symmetry states have been identified in the neutron proton version of the Interacting Boson Model. The motivation of this experiment is to identify uniquely one phonon mixed symmetry states in 140 Ba nuclei by g factor measurement of the states. Magnetic moments measurements provide substantial information on the microscopic structure of the nuclei as the magnetic moment of a nuclei is described by the wave function of one state only. In this present paper we report the preliminary results of the g factor measurement of the first 2 + state of 140 Ba
Magnetic moments in calcium isotopes via a surface-interaction experiment
International Nuclear Information System (INIS)
Niv, Y.; Hass, M.; Zemel, A.; Goldring, G.
1979-01-01
A rotation of the angular correlation of de-excitation γ-rays from 40 Ca and 44 Ca was observed in a tilted foil geometry. The signs and magnitudes of the magnetic moments of the 2 1 + of 44 Ca and of the 3 1 - level of 40 Ca were determined to be g = -0.28+-0.11 and g = +0.52+-0.18, respectively. This experiment provides further information regarding the polarization of deeply bound electronic configurations produced by a surface-interaction mechanism and demonstrates the feasibility of the present technique for measuring signs and magnitudes of magnetic moments of picosecond nuclear levels. (author)
On pho (ω) → πγ decays and anomalous magnetic moment of quarks
International Nuclear Information System (INIS)
Aznauryan, I.G.; Ter-Isaakyan, N.L.
1978-01-01
The pho → πγ and ω → πγ decays are considered in the framework of two-quark model for mesons. It is assumed that the presence of a unitary-singlet part in the anomalous magnetic moment of quarks is at nearly 10% level of the normal magnetic moment. It is shown that one can eliminate the discrepancy between the predictions of quark models and the experiment as regards the ratio of pho(ω) → πγ decays without breaking the assumption on the two-quark structure of mesons
Magnetic dipole moment of Zb(10610 ) in light-cone QCD
Özdem, U.; Azizi, K.
2018-01-01
The magnetic dipole moment of the exotic Zb(10610 ) state is calculated within the light cone QCD sum rule method using the diquark-antidiquark and molecule interpolating currents. The magnetic dipole moment is obtained as μZb=1.73 ±0.63 μN in diquark-antidiquark picture and μZb=1.59 ±0.58 μN in the molecular case. The obtained results in both pictures together with the results of other theoretical studies on the spectroscopic parameters of the Zb(10610 ) state may be useful in determination of the nature and quark organization of this state.
Magnetic moments of light nuclei within the framework of reduced Hamiltonian method
Deveikis, A
1998-01-01
A new procedure for evaluation of magnetic dipole moments of light atomic nuclei has been developed. The procedure presented obeys the principles of antisymmetry and translational invariance and is based on the reduced Hamiltonian method. The theoretical formulation has been illustrated by calculation of magnetic dipole moments for 2 sup H , 3 sup H , 3 sup H e, 4 sup H e, 5 sup H e, 5 sup L i, 11 sup L i, and 6 sup L i nuclei. The calculations were performed in a complete 0(h/2 pi)omega basis. The obtained results are in good agreement with the experimental data. (author)
Magnetic moments and metallic behavior of two-dimensional Ni clusters
International Nuclear Information System (INIS)
Rodriguez L, J.L.; Aguilera G, F.; Vega, A.
1998-01-01
We have calculated the average magnetic moments per atom μ - of two-dimensional nickel clusters (Ni N ) with different geometrical shapes and two different sizes (N=7 and 19). The spin-polarized electronic structure has been calculated with a self-consistent tight-binding method considering the 3d, 4s and 4p valence electrons. We discuss the dependence of the s, p, and d contribution of the magnetic moment on the geometrical shape and the average coordination number. We also study the nonmetal-metal transition of the two-dimensional clusters using Kubo's criterion. (Author)
Energy Technology Data Exchange (ETDEWEB)
Azizi, K. [Middle East Technical University, Physics Department, Ankara (Turkey)
2009-05-15
Due to the very short lifetime of the {delta} baryons, a direct measurement on the electromagnetic moments of these systems is almost impossible in the experiment and can only be done indirectly. Although only for the magnetic dipole moments of {delta}{sup ++} and {delta}{sup +} systems there are some experimental data, the theoretical, phenomenological and lattice calculations could play crucial role. In the present work, the magnetic dipole ({mu}{sub {delta}}), electric quadrupole (Q{sub {delta}}) and magnetic octupole (O{sub {delta}}) moments of these baryons are computed within the light cone QCD sum rules. The results are compared with the predictions of the other phenomenological approaches, lattice QCD and existing experimental data. (orig.)
The magnetic moment of Ni in the Laves phase compound GdNi2
International Nuclear Information System (INIS)
Yano, Kazuo; Umehara, Izuru; Miyazawa, Tomoaki; Adachi, Yoshiya; Sato, Kiyoo
2005-01-01
Magnetization and inverse susceptibility of the Laves phase compound GdNi 2 were investigated and analyzed in detail by employing molecular-field analysis. Both the temperature dependence of the magnetization and the Curie-Weiss (C-W) law-like linear relationship of inverse susceptibility are reproduced in terms of a two-sublattice model and it is seen that the magnetic structure of GdNi 2 is ferrimagnetic and Ni in GdNi 2 retains a magnetic moment of about 0.24μ B
Magnetic dipole moment of the doubly closed-shell plus one proton nucleus $^{49}$Sc
Gaulard, C V; Walters, W; Nishimura, K; Muto, S; Bingham, C R
It is proposed to measure the magnetic moment of $^{49}$Sc by the Nuclear Magnetic Resonance on Oriented Nuclei (NMR-ON) method using the NICOLE on-line nuclear orientation facility. $^{49}$Sc is the neutron rich, doubly closed-shell, nucleus $^{48}$Ca plus one proton. Results will be used to deduce the effective g-factors in the $^{48}$Ca region with reference to nuclear structure and meson exchange current effects.
Classical relativistic spinning particle with anomalous magnetic moment: The precession of spin
International Nuclear Information System (INIS)
Barut, A.O.; Cruz, M.G.
1993-05-01
The theory of classical relativistic spinning particles with c-number internal spinor variables, modelling accurately the Dirac electron, is generalized to particles with anomalous magnetic moments. The equations of motion are derived and the problem of spin precession is discussed and compared with other theories of spin. (author). 32 refs
Large anomalous magnetic moment in three-dimensional Dirac and Weyl semimetals
Van Der Wurff, E. C I; Stoof, H. T C
2016-01-01
We investigate the effect of Coulomb interactions on the electromagnetic response of three-dimensional Dirac and Weyl semimetals. In a calculation reminiscent of Schwinger's seminal work on quantum electrodynamics, we find three physically distinct effects for the anomalous magnetic moment of the
Measurement of the negative muon anomalous magnetic moment to 0.7 ppm
Bennett, GW; Bousquet, B; Brown, HN; Bunce, G; Carey, RM; Cushman, P; Danby, GT; Debevec, PT; Deile, M; Deng, H; Dhawan, SK; Druzhinin, VP; Duong, L; Farley, FJM; Fedotovich, GV; Gray, FE; Grigoriev, D; Grosse-Perdekamp, M; Grossmann, A; Hare, MF; Hertzog, DW; Huang, [No Value; Hughes, VW; Iwasaki, M; Jungmann, K; Kawall, D; Khazin, BI; Krienen, F; Kronkvist, [No Value; Lam, A; Larsen, R; Lee, YY; Logashenko, [No Value; McNabb, R; Meng, W; Miller, JP; Morse, WM; Nikas, D; Onderwater, CJG; Orlov, Y; Ozben, CS; Paley, JM; Peng, Q; Polly, CC; Pretz, J; Prigl, R; Putlitz, GZ; Qian, T; Redin, SI; Rind, O; Roberts, BL; Ryskulov, N; Semertzidis, YK; Shagin, P; Shatunov, YM; Sichtermann, EP; Solodov, E; Sossong, M; Sulak, LR; Trofimov, A; von Walter, P; Yamamoto, A; Huang, X; Kronkvist, I.; Logashenko, I.; Özben, C.S.; Polley, C.C.; Shatunov, Yu.M.; von Walter, R.
2004-01-01
The anomalous magnetic moment of the negative muon has been measured to a precision of 0.7 ppm (ppm) at the Brookhaven Alternating Gradient Synchrotron. This result is based on data collected in 2001, and is over an order of magnitude more precise than the previous measurement for the negative muon.
The classical equations of motion for a spinning point particle with charge and magnetic moment
International Nuclear Information System (INIS)
Rowe, E.G.P.; Rowe, G.T.
1987-01-01
The classical, special relativistic equations of motion are derived for a spinning point particle interacting with the electromagnetic field through its charge and magnetic moment. Radiation reaction is included. The energy tensors for the particle and for the field are developed as well-defined distributions; consequently no infinities appear. The magnitude of spin and the rest mass are conserved. (orig.)
Nuclear Magnetic Moment of 59Cu with On-line $\\beta$-NMR on Oriented Nuclei
Golovko, V V; Phalet, T; Severijns, N; Delauré, B J; Beck, M; Kozlov, Yu V; Lindroth, A; Versyck, S; Zákoucký, D; Vénos, D; Srnka, D; Honusek, M; Herzog, P; Tramm, C; Köster, U; Towner, I S
2004-01-01
The nuclear magnetic moment of the nucleus 59Cu with one proton and two neutrons outside the closed N = Z = 28 shells, was measured in an on-line experiment combining beta-NMR with low temperature nuclear orientation and with particle detectors operating at a temperature of about 10K. From the data the center frequency \
Nuclear magnetic moment of $^{59}$Cu with on-line $\\beta$-NMR on oriented nuclei
Golovko, V V; Phalet, T; Severijns, N; Delauré, B J; Beck, M; Kozlov, V; Lindroth, A; Versyck, S; Zákoucký, D; Srnka, D; Honusek, M; Herzog, P; Köster, U; Tramm, C; Towner, I S
2004-01-01
The nuclear magnetic moment of the nucleus $^{59}\\!$Cu, with one proton and two neutrons outside the closed N = Z = 28 shells, was measured in an on-line experiment combining $\\beta$-NMR with low temperature nuclear orientation and with particle detectors operating at a temperature of about 10 K. From the data the center frequency $\
Unimodular gravity and the lepton anomalous magnetic moment at one-loop
Energy Technology Data Exchange (ETDEWEB)
Martín, Carmelo P., E-mail: carmelop@fis.ucm.es [Departamento de Física Teórica I, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, 28040 Madrid (Spain)
2017-07-01
We work out the one-loop contribution to the lepton anomalous magnetic moment coming from Unimodular Gravity. We use Dimensional Regularization and Dimensional Reduction to carry out the computations. In either case, we find that Unimodular Gravity gives rise to the same one-loop correction as that of General Relativity.
Final report of the E821 muon anomalous magnetic moment measurement at BNL
Bennett, GW; Bousquet, B; Brown, HN; Bunce, G; Carey, RM; Cushman, P; Danby, GT; Debevec, PT; Deile, M; Deng, H; Deninger, W; Dhawan, SK; Druzhinin, VP; Duong, L; Efstathiadis, E; Farley, FJM; Fedotovich, GV; Giron, S; Gray, FE; Grigoriev, D; Grosse-Perdekamp, M; Grossmann, A; Hare, MF; Hertzog, DW; Huang, [No Value; Hughes, VW; Iwasaki, M; Jungmann, Klaus-Peter; Kawall, D; Kawamura, M; Khazin, BI; Kindem, J; Krienen, F; Kronkvist, [No Value; Lam, A; Larsen, R.; Lee, YY; Logashenko, [No Value; McNabb, R; Meng, W; Mi, J; Miller, JP; Mizumachi, Y; Morse, WM; Nikas, D; Onderwater, Gerco; Orlov, Y; Ozben, CS; Paley, JM; Peng, Q; Polly, CC; Pretz, J; Prigl, R; Putlitz, GZ; Qian, T; Redin, SI; Rind, O; Roberts, BL; Ryskulov, N; Sedykh, S; Semertzidis, YK; Shagin, P; Shatunov, YM; Sichtermann, EP; Solodov, E; Sossong, M; Steinmetz, A; Sulak, LR; Timmermans, C; Trofimov, A; Urner, D; von Walter, P; Warburton, D; Winn, D; Yamamoto, A; Zimmerman, D
We present the final report from a series of precision measurements of the muon anomalous magnetic moment, a(mu)=(g-2)/2. The details of the experimental method, apparatus, data taking, and analysis are summarized. Data obtained at Brookhaven National Laboratory, using nearly equal samples of
Energy Technology Data Exchange (ETDEWEB)
Kong, Tai [Iowa State Univ., Ames, IA (United States)
2016-12-17
Benefiting from unique properties of 4f electrons, rare earth based compounds are known for offering a versatile playground for condensed matter physics research as well as industrial applications. This thesis focuses on three specific examples that further explore the rare earth local moment magnetism and strongly correlated phenomena in various crystal structures.
Constraints on a preonic model for family replication from the anomalous magnetic moment of leptons
International Nuclear Information System (INIS)
Godbole, R.M.
1986-07-01
The additional contributions to the anomalous magnetic moment of the muon and the electron ((g-2) l ) in a recently suggested preonic model are considered. It is shown that the parameters in this model are severely restricted when the constraints coming from this analysis are combined with those obtained from the considerations of the quark-lepton mass matrices and mixing angles. (author)
Spontaneous Magnetization in the Dipolar Ising Ferromagnet LiTbF4
DEFF Research Database (Denmark)
Als-Nielsen, Jens Aage; Holmes, L. M.; Krebs Larsen, F.
1975-01-01
The spontaneous magnetization μ in Bohr magnetons below TC=2.874 K in LiTbF4 has been measured by magnetic Bragg scattering of neutrons. The data were normalized by comparing the magnetic Bragg scattering to the nuclear Bragg scattering at T>TC. The nuclear structure factors as well as the extinc......The spontaneous magnetization μ in Bohr magnetons below TC=2.874 K in LiTbF4 has been measured by magnetic Bragg scattering of neutrons. The data were normalized by comparing the magnetic Bragg scattering to the nuclear Bragg scattering at T>TC. The nuclear structure factors as well...
Energy Technology Data Exchange (ETDEWEB)
Aguirre, R.M.; Paoli, A.L. de [Universidad Nacional de La Plata, and IFLP, Departamento de Fisica, Facultad de Ciencias Exactas, La Plata (Argentina)
2016-11-15
We obtain the covariant propagator at finite temperature for interacting baryons immersed in a strong magnetic field. The effect of the intrinsic magnetic moments on the Green function are fully taken into account. We make an expansion in terms of eigenfunctions of a Dirac field, which leads us to a compact form of its propagator. We present some simple applications of these propagators, where the statistical averages of nuclear currents and energy density are evaluated. (orig.)
Alling, B.; Kormann, F.H.W.; Grabowski, B; Glensk, A; Abrikosov, I.A.
2016-01-01
We study the impact of lattice vibrations on magnetic and electronic properties of paramagnetic bcc and fcc iron at finite temperature, employing the disordered local moments molecular dynamics (DLM-MD) method. Vibrations strongly affect the distribution of local magnetic moments at finite
International Nuclear Information System (INIS)
Morris, D.A.
1988-01-01
We examine contributions to the anomalous magnetic moment of the muon from weak-isosinglet squarks found in E 6 superstring models. We find that such contributions are up to 2 orders of magnitude larger than those previously calculated and correspondingly require smaller Yukawa couplings in order to maintain agreement with the measured muon anomalous magnetic moment
Development of magnetic moments in Fe{sub 1-x}Ni{sub x} - alloys
Energy Technology Data Exchange (ETDEWEB)
Glaubitz, Benjamin; Buschhorn, Stefan; Bruessing, Frank; Zabel, Hartmut [Festkoerperphysik, Ruhr-Universitaet Bochum, 44780 Bochum (Germany)
2011-07-01
Fe{sub 1-x}Ni{sub x} alloys have been studied intensively in the past because of their unique properties, such as the soft magnetic properties at x=0.8 and the martensitic bcc-fcc transition at x=0.35. The total magnetic moment as a function of alloy concentration follows by and large the Slater Pauling curve, but not in the region of the martensitic transition, where a strong drop is observed, which has been taken as a sign for strong magneto-volume fluctuations, also known as the invar effect. Using XMCD methods, we have analyzed the individual magnetic moments of Fe and Ni across the alloy concentration range, including their spin and orbital contributions, and we have compared those with the average moments determined by VSM measurements. We find a very good agreement between both methods, with the individual moments showing some fluctuations at the invar concentration but no anomaly. We will discuss the results in the light of recent theoretical predictions.
Sea quarks contribution to the nucleon magnetic moment and charge radius at the physical point
Sufian, Raza Sabbir; Yang, Yi-Bo; Liang, Jian; Draper, Terrence; Liu, Keh-Fei; χ QCD Collaboration
2017-12-01
We report a comprehensive analysis of the light and strange disconnected-sea quarks contribution to the nucleon magnetic moment, charge radius, and the electric and magnetic form factors. The lattice QCD calculation includes ensembles across several lattice volumes and lattice spacings with one of the ensembles at the physical pion mass. We adopt a model-independent extrapolation of the nucleon magnetic moment and the charge radius. We have performed a simultaneous chiral, infinite volume, and continuum extrapolation in a global fit to calculate results in the continuum limit. We find that the combined light and strange disconnected-sea quarks contribution to the nucleon magnetic moment is μM(DI )=-0.022 (11 )(09 ) μN and to the nucleon mean square charge radius is ⟨r2⟩E(DI ) =-0.019 (05 )(05 ) fm2 which is about 1 /3 of the difference between the ⟨rp2⟩E of electron-proton scattering and that of a muonic atom and so cannot be ignored in obtaining the proton charge radius in the lattice QCD calculation. The most important outcome of this lattice QCD calculation is that while the combined light-sea and strange quarks contribution to the nucleon magnetic moment is small at about 1%, a negative 2.5(9)% contribution to the proton mean square charge radius and a relatively larger positive 16.3(6.1)% contribution to the neutron mean square charge radius come from the sea quarks in the nucleon. For the first time, by performing global fits, we also give predictions of the light and strange disconnected-sea quarks contributions to the nucleon electric and magnetic form factors at the physical point and in the continuum and infinite volume limits in the momentum transfer range of 0 ≤Q2≤0.5 GeV2 .
The QED vacuum polarization function at four loops and the anomalous magnetic moment at five loops
International Nuclear Information System (INIS)
Baikov, P.
2013-07-01
The anomalous moment of the muon is one of the most fundamental observables. It has been measured experimentally with a very high precision and on theory side the contributions from perturbative QED have been calculated up to five-loop level by numerical methods. Contributions to the muon anomalous magnetic moment from certain diagram classes are also accessible by alternative methods. In this paper we present the evaluation of contributions to the QCD corrections due to insertions of the vacuum polarization function at five-loop level.
Energy Technology Data Exchange (ETDEWEB)
Hernando, Antonio; Crespo, Patricia [Instituto de Magnetismo Aplicado, UCM-CSIC-ADIF, Las Rozas. P.O. Box 155, 28230 Madrid (Spain); Dept. Fisica de Materiales, Universidad Complutense, Madrid (Spain); Garcia, Miguel Angel [Instituto de Ceramica y Vidrio, CSIC, C/ Kelsen, 5, Madrid 28049 (Spain); Coey, Michael [Trinity College Dublin, Dublin (Ireland); Ayuela, Andres; Echenique, Pedro Miguel [Centro de Fisica de Materiales, CFM-MPC CSIC-UPV/EHU, Donostia International Physics Center (DIPC), 20018 San Sebastian (Spain); Departamento de Fisica de Materiales, Fac. de Quimicas, Universidad del Pais Vasco UPV-EHU, 20018 San Sebastian (Spain)
2011-10-15
In this article we review the exotic magnetism of nanoparticles (NPs) formed by substances that are not magnetic in bulk as described with generality in Section 1. In particular, the intrinsic character of the magnetism observed on capped Au and ZnO NPs is analysed. X-ray magnetic circular dichroism (XMCD) analysis has shown that the magnetic moments are intrinsic and lie in the Au and Zn atoms, respectively, as analysed in Section 2, where the general theoretical ideas are also revisited. Since impurity atoms bonded to the surface act as donor or acceptor of electrons that occupy the surface states, the anomalous magnetic response is analysed in terms of the surface band in Section 3. Finally, Section 4 summarizes our last theoretical proposal. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Isaguliants, M G; Ozeretskovskaia, N N; Znoĭko, O O; Tsyganova, E V
2008-01-01
The condition of the host at the moment of infection is that its immune competence largely determines the efficiency, kinetics, and profile (Thl/Th2) of a further specific immunity response and, accordingly, the outcome of penetration of hepatitis C virus (HCV) into the body and subsequent acute infection (if it occurs). The parameters determining immune competence may include age, traumatizing exposures (operations, burns, wounds, and fractures), immunosuppressive therapy, stresses, con-infections, and alcohol use. The highest rates of spontaneous convalescence from HCV infection are observed in children and adolescents. Other human conditions are much shorter, transient; their impact is difficult to determine in the retrospective review and therefore it has not been adequately studied. Previous operations, posttransplantation immune suppression, immune modulation after blood transfusion, alcohol-induced immune imbalance, drug and narcotic intoxication are poor predictors. Immunosuppression and immune imbalance caused by viral and parasitic infections are observed among the host's temporary conditions affecting the outcome of HCV infection. The authors have analyzed the sequels of superinfections in patients with chronic hepatitis C, other hepatotropic viruses and the common liver fluke Schistosoma mansoni. The interesting therapeutic activities against HCV and parasitic infection (contamination with Echinococcus granulosus in particular), which are shown in the treatment of co-infection patients with alpha-interferon preparations that ensure normalization of immune deficiency caused by each of the infections and their increased combination. A deeper insight into the correlation between the condition of the host and its ability to eliminate the virus may be one more step on the road to the prevention of the infection and to the designing an effective vaccine against HCV.
Spins and magnetic moments of 58;60;62;64Mn ground states and isomers
Heylen, H; Billowes, J; Bissell, M L; Blaum, K; Campbell, P; Cheal, B; Ruiz, R F Garcia; Geppert, Ch; Gins, W; Kowalska, M; Kreim, K; Lenzi, S M; Moore, I D; Neugart, R; Neyens, G; Nörtershäuser, W; Papuga, J; Yordanov, D T
2015-01-01
The odd-odd 54;56;58;60;62;64Mn isotopes (Z = 25) were studied using bunched-beam collinear laser spectroscopy at ISOLDE, CERN. From the measured hyperfine spectra the spins and magnetic moments of Mn isotopes up to N = 39 were extracted. The previous tentative ground state spin assignments of 58;60;62;64Mn are now firmly determined to be I = 1 along with an I = 4 assignment for the isomeric states in 58;60;62Mn. The I = 1 magnetic moments show a decreasing trend with increasing neutron number while the I = 4 moments remain quite constant between N = 33 and N = 37. The results are compared to large-scale shell-model calculations using the GXPF1A and LNPS effective interactions. The excellent agreement of the ground state moments with the predictions from the LNPS calculations illustrates the need for an increasing amount of proton excitations across Z = 28 and neutron excitations across N = 40 in the ground state wave functions from N = 37 onwards.
The MOMENT Magnetic-Mapping Mission: A Nanosatellite for the Scientific Exploration of Mars
Eagleson, S.; Mauthe, S.; Sarda, K.; Spencer, H.; Zee, R. E.; Arkani-Hammed, J.
2008-08-01
MOMENT (Magnetic Observations of Mars Enabled by Nanosatellite Technology) is a nanosatellite that will obtain high-resolution maps of remnant magnetic fields present in the southern highlands of Mars. A European-developed magnetometer accurate to bet- ter than 0.5 nT and employed in a highly elliptical orbit with a relatively low, 100 km night-side, periapsis will provide much greater spatial resolution and delineation of local magnetic anomalies than is available from the initial surveys performed by Mars Global Surveyor (MGS). During the aerobraking phase of the MGS mission, low-altitude measurements were corrupted by solar wind because they were acquired under sunlit conditions where solar winds interacted with the crustal magnetic fields. During the mapping phase of the mission, spatial resolution was limited to about 400 km. Both of these issues will be overcome by MOMENT's low-altitude, night-side, observing strategy. The resulting magnetic-field maps, for the key areas of interest, will allow detailed studies of regional tectonics and the history of the planet's now- inactive core dynamo. MOMENT's design is based on the Space Flight Laboratory's Generic Nanosatellite Bus (GNB), which is also being developed for the BRITE space-astronomy and CanX-4&5 formation- flight missions. Nominally a 30 x 30 x 30 cm cube on the order of 10 kg mass, MOMENT uses as much GNB technology as possible to provide a rapid and cost-effective mission. The implementation of the mission requires payload space on a larger carrier spacecraft and the use of existing and future Martian communication relays for the transfer of information to and from Earth, necessitating a high level of international co-operation. MOMENT is otherwise fully independent and autonomous, even during scientific operations. This paper describes the conceptual (Canadian Space Agency funded) MOMENT mission and presents a strong case for the use of nanosatellite technology as a relatively simple and cost
Three types magnetic moment distribution of nonlinear excitations in a Heisenberg helimagnet
Energy Technology Data Exchange (ETDEWEB)
Qi, Jian-Wen [School of Physics, Northwest University, Xi' an 710069 (China); Shaanxi Key Laboratory for Theoretical Physics Frontiers, Xi' an 710069 (China); Li, Zai-Dong [Department of Applied Physics, Hebei University of Technology, Tianjin 300401 (China); Yang, Zhan-Ying, E-mail: zyyang@nwu.edu.cn [School of Physics, Northwest University, Xi' an 710069 (China); Shaanxi Key Laboratory for Theoretical Physics Frontiers, Xi' an 710069 (China); Yang, Wen-Li [Shaanxi Key Laboratory for Theoretical Physics Frontiers, Xi' an 710069 (China); Institute of Modern Physics, Northwest University, Xi' an 710069 (China)
2017-06-15
Highlights: • Three different types of soliton excitations under the spin-wave background are demonstrated in spin chain system. • The magnetic moment distributions corresponding to these solitons are characterized in detail. • The formation mechanisms of those excitations are explained by the magnon density distribution. - Abstract: We study the nonlinear spin dynamics of an anisotropic Heisenberg helimagnet in a fourth-order integrable nonlinear Schrödinger equation. We demonstrate that there are three types of nonlinear spin excitations on a spin-wave background in the Heisenberg helimagnet, notably including anti-dark soliton, W-shaped soliton, and multi-peak soliton. The magnetic moment distribution that corresponds to each of these are characterized in detail. Additionally, the formation mechanism is clarified by the magnon density distribution.
1/Nc rotational corrections to gA and isovector magnetic moment of the nucleon
Christov, Chr. V.; Blotz, A.; Goeke, K.; Pobilitsa, P.; Petrov, V.; Wakamatsu, M.; Watabe, T.
1994-04-01
The 1/Nc rotational corrections to the axial vector constant and the isovector magnetic moment of the nucleon are studied in the Nambu-Jona-Lasinio model. We follow a semiclassical quantization procedure in terms of path integrals in which we can include perturbatively corrections in powers of angular velocity Ω ~ 1/Nc. We find non-zero 1/Nc order corrections from both the valence and the Dirac sea quarks. These corrections are large enough to resolve the long-standing problem of a strong underestimation of both gA and μIV in the leading order. For the constituent quark mass of about 400 MeV the axial constant gA is well reproduced, whereas the isovector magnetic moment μIV is still underestimated by 25 %.
Nuclear magnetic moment measurements through hyperfine interactions in highly stripped ions
International Nuclear Information System (INIS)
Horstman, R.E.
1975-01-01
Time-differential magnetic moment measurements on the first-excited Isup(π)=2 + states in 20 Ne and 24 Mg with mean lives of 1.0 and 2.1 ps, respectively are described. The lifetime of the latter state was determined simultaneously. A special detection geometry was designed to improve the experimental γ-ray anisotropy measured with finite-size detectors. For 20 Ne also a time-integral measurement with charge-state separation was performed. The necessary electronics circuitry built to perform these complicated measurements and the plunger assembly with laser interferometer are also described. A magnetic moment measurement of 22 Ne(2 1 + ) with tau=5.0 ps and transient field measurements at low and high recoil velocities are reported. A discussion of possible extensions of the techniques are given. (Auth.)
A parts-per-billion measurement of the antiproton magnetic moment
Smorra, C.; Sellner, S.; Borchert, M. J.; Harrington, J. A.; Higuchi, T.; Nagahama, H.; Tanaka, T.; Mooser, A.; Schneider, G.; Bohman, M.; Blaum, K.; Matsuda, Y.; Ospelkaus, C.; Quint, W.; Walz, J.; Yamazaki, Y.; Ulmer, S.
2017-10-01
Precise comparisons of the fundamental properties of matter–antimatter conjugates provide sensitive tests of charge–parity–time (CPT) invariance, which is an important symmetry that rests on basic assumptions of the standard model of particle physics. Experiments on mesons, leptons and baryons have compared different properties of matter–antimatter conjugates with fractional uncertainties at the parts-per-billion level or better. One specific quantity, however, has so far only been known to a fractional uncertainty at the parts-per-million level: the magnetic moment of the antiproton, . The extraordinary difficulty in measuring with high precision is caused by its intrinsic smallness; for example, it is 660 times smaller than the magnetic moment of the positron. Here we report a high-precision measurement of in units of the nuclear magneton μN with a fractional precision of 1.5 parts per billion (68% confidence level). We use a two-particle spectroscopy method in an advanced cryogenic multi-Penning trap system. Our result = ‑2.7928473441(42)μN (where the number in parentheses represents the 68% confidence interval on the last digits of the value) improves the precision of the previous best measurement by a factor of approximately 350. The measured value is consistent with the proton magnetic moment, μp = 2.792847350(9)μN, and is in agreement with CPT invariance. Consequently, this measurement constrains the magnitude of certain CPT-violating effects to below 1.8 × 10‑24 gigaelectronvolts, and a possible splitting of the proton–antiproton magnetic moments by CPT-odd dimension-five interactions to below 6 × 10‑12 Bohr magnetons.
N=2-Maxwell-Chern-Simons model with anomalous magnetic moment coupling via dimensional reduction
International Nuclear Information System (INIS)
Christiansen, H.R.; Cunha, M.S.; Helayel Neto, Jose A.; Manssur, L.R.U; Nogueira, A.L.M.A.
1998-02-01
An N=1-supersymmetric version of the Cremmer-Scherk-Kalb-Ramond model with non-minimal coupling to matter is built up both in terms of superfields and in a component field formalism. By adopting a dimensional reduction procedure, the N=2-D=3 counterpart of the model comes out, with two main features: a genuine (diagonal) Chern-Simons term and an anomalous magnetic moment coupling between matter and the gauge potential. (author)
Precision measurement of the hadronic contribution to the muon anomalous magnetic moment
Xiao, T.; Dobbs, S.; Tomaradze, A.; Seth, Kamal K.; Bonvicini, G.
2018-02-01
We report on a precision measurement of the cross section for the reaction e+e-→π+π- in the mass range 0.30 muon anomalous magnetic moment calculated using these measured e+e-→π+π- cross sections in the range Mπ π=0.30 to 1.00 GeV /c2 is calculated to be (500.6 ±3.6 (stat )±8.0 (syst ))×10-10 .
A parts-per-billion measurement of the antiproton magnetic moment.
Smorra, C; Sellner, S; Borchert, M J; Harrington, J A; Higuchi, T; Nagahama, H; Tanaka, T; Mooser, A; Schneider, G; Bohman, M; Blaum, K; Matsuda, Y; Ospelkaus, C; Quint, W; Walz, J; Yamazaki, Y; Ulmer, S
2017-10-18
Precise comparisons of the fundamental properties of matter-antimatter conjugates provide sensitive tests of charge-parity-time (CPT) invariance, which is an important symmetry that rests on basic assumptions of the standard model of particle physics. Experiments on mesons, leptons and baryons have compared different properties of matter-antimatter conjugates with fractional uncertainties at the parts-per-billion level or better. One specific quantity, however, has so far only been known to a fractional uncertainty at the parts-per-million level: the magnetic moment of the antiproton, . The extraordinary difficulty in measuring with high precision is caused by its intrinsic smallness; for example, it is 660 times smaller than the magnetic moment of the positron. Here we report a high-precision measurement of in units of the nuclear magneton μ N with a fractional precision of 1.5 parts per billion (68% confidence level). We use a two-particle spectroscopy method in an advanced cryogenic multi-Penning trap system. Our result = -2.7928473441(42)μ N (where the number in parentheses represents the 68% confidence interval on the last digits of the value) improves the precision of the previous best measurement by a factor of approximately 350. The measured value is consistent with the proton magnetic moment, μ p = 2.792847350(9)μ N , and is in agreement with CPT invariance. Consequently, this measurement constrains the magnitude of certain CPT-violating effects to below 1.8 × 10 -24 gigaelectronvolts, and a possible splitting of the proton-antiproton magnetic moments by CPT-odd dimension-five interactions to below 6 × 10 -12 Bohr magnetons.
Rotating effects on the Landau quantization for an atom with a magnetic quadrupole moment
Energy Technology Data Exchange (ETDEWEB)
Fonseca, I. C.; Bakke, K., E-mail: kbakke@fisica.ufpb.br [Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, João Pessoa, PB 58051-970 (Brazil)
2016-01-07
Based on the single particle approximation [Dmitriev et al., Phys. Rev. C 50, 2358 (1994) and C.-C. Chen, Phys. Rev. A 51, 2611 (1995)], the Landau quantization associated with an atom with a magnetic quadrupole moment is introduced, and then, rotating effects on this analogue of the Landau quantization is investigated. It is shown that rotating effects can modify the cyclotron frequency and breaks the degeneracy of the analogue of the Landau levels.
Precise determination of the magnetic moment of helium in its 23S1 metastable state
International Nuclear Information System (INIS)
Zundell, B.E.
1976-01-01
The electronic magnetic moment of helium was measured by the atomic beam magnetic resonance method using separated oscillating fields. Actually, the magnetic moment of helium relative to that of rubidium was measured. The result was combined with the ratio g/sub J/(Rb)/g/sub J/(H) to get R = g/sub J/(He, 2 3 S 1 )/g/sub J/(H, 2 S/sub 1/2/) = 1 - (23.19 +- 0.1) x 10 -6 . The motivation for this Zeeman measurement was to provide as sensitive a test of the theory of atomic magnetism for a multielectron atom as possible. In particular, the experiment provides a test of the relativistic corrections to the Zeeman effect. The experiment also tests the additivity of the radiative corrections to the magnetic moments of the two electrons. Another motivation concerns the determination of the fine structure constant α from measurements of the 2 3 P fine structure intervals of 4 He; namely, the understanding of the 2 3 S states contributes to the knowledge of the theoretical expressions for the 2 3 P intervals. For the chosen magnetic field of 9.5 kG, the helium resonance frequency was 26.8 GHz, the rubidium frequency, 26.4 GHz. The linewidth associated with the microwave double loop was 25 KHz. Thus it was necessary to pick the resonance line centers to only 1 part in 10 to achieve a 0.1 ppM accuracy. This result is in excellent agreement with the latest theoretical value, R = 1 - 23.21 x 10 -6 ; and with earlier, less precise atomic beam measurements; and with the latest, comparably accurate optical pumping value. Many possible sources of error were investigated. The quoted error is based on analysis of residual systematic effects
Solar and atmospheric neutrinos in three generations with a magnetic moment
International Nuclear Information System (INIS)
Pulido, J.; Tao, Z.
1995-01-01
A solution to the solar and atomospheric neutrino problems in three generations in the joint context of matter oscillations and the magnetic moment is investigated. An appropriate rotation of the evolution Hamiltonian reduces the three generation case to a two generation one. A convenient background for such a scenario with small neutrino masses and large magnetic moments is given by the Zee-type models, in which the mass generation mechanism leads to a pair of separate orders of magnitude for the mass square differences between neutrino species. We obtain a ratio var-epsilon congruent 10 -2 --10 -3 between these orders of magnitude, so that one of them [(0.3--3)x10 -2 eV 2 ] is suitable for the atmospheric neutrino solution and the other (∼10 -5 eV 2 ) for the solar neutrino solution. The magnetic moment leads to a decrease of the survival probability with solar neutrino energy. Such a decrease is consistent with the experimental situation
Strange Quark Magnetic Moment of the Nucleon at the Physical Point.
Sufian, Raza Sabbir; Yang, Yi-Bo; Alexandru, Andrei; Draper, Terrence; Liang, Jian; Liu, Keh-Fei
2017-01-27
We report a lattice QCD calculation of the strange quark contribution to the nucleon's magnetic moment and charge radius. This analysis presents the first direct determination of strange electromagnetic form factors including at the physical pion mass. We perform a model-independent extraction of the strange magnetic moment and the strange charge radius from the electromagnetic form factors in the momentum transfer range of 0.051 GeV^{2}≲Q^{2}≲1.31 GeV^{2}. The finite lattice spacing and finite volume corrections are included in a global fit with 24 valence quark masses on four lattices with different lattice spacings, different volumes, and four sea quark masses including one at the physical pion mass. We obtain the strange magnetic moment G_{M}^{s}(0)=-0.064(14)(09)μ_{N}. The four-sigma precision in statistics is achieved partly due to low-mode averaging of the quark loop and low-mode substitution to improve the statistics of the nucleon propagator. We also obtain the strange charge radius ⟨r_{s}^{2}⟩_{E}=-0.0043(16)(14) fm^{2}.
Gd-doped BaSnO3: A transparent conducting oxide with localized magnetic moments
Alaan, Urusa S.; Shafer, Padraic; N'Diaye, Alpha T.; Arenholz, Elke; Suzuki, Y.
2016-01-01
We have synthesized transparent, conducting, paramagnetic stannate thin films via rare-earth doping of BaSnO3. Gd3+ (4f7) substitution on the Ba2+ site results in optical transparency in the visible regime, low resistivities, and high electron mobilities, along with a significant magnetic moment. Pulsed laser deposition was used to stabilize epitaxial Ba0.96Gd0.04SnO3 thin films on (001) SrTiO3 substrates, and compared with Ba0.96La0.04SnO3 and undoped BaSnO3 thin films. Gd as well as La doping schemes result in electron mobilities at room temperature that exceed those of conventional complex oxides, with values as high as 60 cm2/V.s (n = 2.5 × 1020 cm-3) and 30 cm2/V.s (n = 1 × 1020 cm-3) for La and Gd doping, respectively. The resistivity shows little temperature dependence across a broad temperature range, indicating that in both types of films the transport is not dominated by phonon scattering. Gd-doped BaSnO3 films have a strong magnetic moment of ˜7 μB/Gd ion. Such an optically transparent conductor with localized magnetic moments may unlock opportunities for multifunctional devices in the design of next-generation displays and photovoltaics.
Magnetic dipole moments of High-K isomeric states in Hf isotopes
Walters, W; Nishimura, K; Bingham, C R
2007-01-01
It is proposed to make precision measurements of the magnetic moments of 5 multi-quasi-particle K-isomers in Hf nuclei by the Nuclear Magnetic Resonance of Oriented Nuclei (NMR/ON) technique using the NICOLE on-line nuclear orientation facility and exploiting the unique HfF$_{3}$ beams recently available at ISOLDE. Results will be used to extract single-particle and collective g-factors of the isomeric states and their excitations and to shed new light on their structure.
Measurement of the nuclear magnetic moments of 57Ni and 59Fe
International Nuclear Information System (INIS)
Ohtsubo, T.; Cho, D.J.; Yanagihashi, Y.; Ohya, S.; Muto, S.
1996-01-01
The magnetic hyperfine splitting frequencies of (i) 57 Ni in Fe ( 57 NiFe), (ii) 57 Ni in Ni ( 57 NiNi), and (iii) 59 Fe in Fe ( 59 FeFe) were measured with the technique of nuclear magnetic resonance on oriented nuclei (NMR-ON) at low temperatures. The NMR-ON spectra were observed by detecting the β-ray asymmetries. The resonance frequencies at zero external magnetic field were deduced from the extrapolation of the external field dependence of the resonance frequencies: ν( 57 NiFe)=94.23(2) MHz, ν( 57 NiNi)=30.02(4) MHz, and ν( 59 FeFe)=57.719(11) MHz. With the known hyperfine fields of B HF (NiNi)=-7.406(8) T and B HF (FeFe)=-33.82(3) T, the magnetic moments of 57 Ni and 59 Fe were determined to be μ( 57 Ni)=-0.7975(14)μ N and μ( 59 Fe)=-0.3358(4)μ N . The precise value of the hyperfine field of B HF ( 57 NiFe) was also deduced as -23.25(5) T. The measured values of the magnetic moment are compared with those based on the shell model. copyright 1996 The American Physical Society
Chiral structures and tunable magnetic moments in 3d transition metal doped Pt6 clusters
International Nuclear Information System (INIS)
Zhang Xiu-Rong; Yang Xing; Ding Xun-Lei
2012-01-01
The structural, electronic, and magnetic properties of transition metal doped platinum clusters MPt 6 (M=Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn) are systematically studied by using the relativistic all-electron density functional theory with the generalized gradient approximation. Most of the doped clusters show larger binding energies than the pure Pt 7 cluster, which indicates that the doping of the transition metal atom can stabilize the pure platinum cluster. The results of the highest occupied molecular orbital (HOMO)—lowest unoccupied molecular orbital (LUMO) gaps suggest that the doped clusters can have higher chemical activities than the pure Pt 7 cluster. The magnetism calculations demonstrate that the variation range of the magnetic moments of the MPt 6 clusters is from 0 μ B to 7 μ B , revealing that the MPt 6 clusters have potential utility in designing new spintronic nanomaterials with tunable magnetic properties
Lifting particle coordinate changes of magnetic moment type to Vlasov-Maxwell Hamiltonian dynamics
International Nuclear Information System (INIS)
Morrison, P. J.; Vittot, M.; Guillebon, L. de
2013-01-01
Techniques for coordinate changes that depend on both dependent and independent variables are developed and applied to the Maxwell-Vlasov Hamiltonian theory. Particle coordinate changes with a new velocity variable dependent on the magnetic field, with spatial coordinates unchanged, are lifted to the field theoretic level, by transforming the noncanonical Poisson bracket and Hamiltonian structure of the Vlasov-Maxwell dynamics. Several examples are given including magnetic coordinates, where the velocity is decomposed into components parallel and perpendicular to the local magnetic field, and the case of spherical velocity coordinates. An example of the lifting procedure is performed to obtain a simplified version of gyrokinetics, where the magnetic moment is used as a coordinate and the dynamics is reduced by elimination of the electric field energy in the Hamiltonian.
Shell effect in the mean square charge radii and magnetic moments of bismuth isotopes near N =126
Barzakh, A. E.; Fedorov, D. V.; Ivanov, V. S.; Molkanov, P. L.; Moroz, F. V.; Orlov, S. Yu.; Panteleev, V. N.; Seliverstov, M. D.; Volkov, Yu. M.
2018-01-01
Isotope shift relative to 209Bi and hyperfine splitting for Bi,213211 have been measured by in-source laser spectroscopy at the 306.77-nm atomic transition. The pronounced shell effect both in radii and magnetic moments in Bi isotopes at N =126 has been observed. The isotopic trend of magnetic moment for 9 /2- ground states of even-N Bi isotopes has been qualitatively explained by the change in the first-order core-polarization correction. The possible influence of the octupole degree of freedom on the magnetic moment behavior at N >126 has been discussed.
Rollins, Nancy K.; Liang, Hui; Park, Yong Jong
2015-01-01
Purpose: Most orthodontic appliances are made of stainless steel materials and induce severe magnetic susceptibility artifacts in brain MRI. In an effort for correcting these artifacts, it is important to know the value of induced magnetic moments in all parts of orthodontic appliances. In this study, the induced magnetic moment of stainless steel orthodontic brackets, molar bands, and arch-wires from several vendors is measured. Methods: Individual stainless steel brackets, molar bands, and short segments of arch-wire were positioned in the center of spherical flask filled with water through a thin plastic rod. The induced magnetic moment at 1.5 T was determined by fitting the B0 map to the z-component of the magnetic dipole field using a computer routine. Results: The induced magnetic moment at 1.5 T was dominated by the longitudinal component mz, with a small contribution from the transverse components. The mz was insensitive to the orientation of the metal parts. The orthodontic brackets collectively dominated the magnetic dipole moment in orthodontic appliances. In brackets from six vendors, the total induced mz from 20 brackets for nonmolar teeth ranged from 0.108 to 0.158 (median 0.122) A ⋅ m2. The mz in eight molar bands with bracket attachment from two vendors ranged from 0.0004 to 0.0166 (median 0.0035) A ⋅ m2. Several full length arch wires had induced magnetic moment in the range of 0.006–0.025 (median 0.015) A ⋅ m2. Conclusions: Orthodontic brackets collectively contributed most to the total magnetic moment. Different types of brackets, molar bands, and arch wires all exhibit substantial variability in the induced magnetic moment. PMID:26429261
van Rijssel, Jozef; Kuipers, Bonny W M; Erne, Ben
2015-01-01
High-frequency applications of magnetic nanoparticles, such as therapeutic hyperthermia and magnetic particle imaging, are sensitive to nanoparticle size and dipole moment. Usually, it is assumed that magnetic nanoparticles with a log-normal distribution of the physical size also have a log-normal
Staunton, Julie B; Marmodoro, Alberto; Ernst, Arthur
2014-07-09
We briefly describe the density functional theory (DFT)-based 'disordered local moment' (DLM) picture for magnetism at finite temperatures. It shows how relatively slowly fluctuating local moments can emerge from the interacting electrons of many materials. Such entities have rigid magnitudes and fluctuate their orientations from atomic site to atomic site on a timescale long compared to other electronic times. We illustrate this theory with calculations of the magnetocaloric effect in Gd where we find excellent agreement with experiments. Fluctuating moments do not appear to establish naturally over such small regions for some other materials. We show how the DFT-DLM theory can be extended to these materials with the use of the Korringa-Kohn-Rostoker nonlocal coherent potential approximation (KKR-NLCPA) to allow for more extensive, slow magnetic fluctuations. We present the first application of this approach by revisiting the description of the magnetic fluctuations prevalent in the paramagnetic state of nickel. We find that local moments can emerge above Tc and that these form coherently over small clumps of atomic sites (4-8 sites).
Spin, quadrupole moment, and deformation of the magnetic-rotational band head in Pb193
Balabanski, D. L.; Ionescu-Bujor, M.; Iordachescu, A.; Bazzacco, D.; Brandolini, F.; Bucurescu, D.; Chmel, S.; Danchev, M.; de Poli, M.; Georgiev, G.; Haas, H.; Hübel, H.; Marginean, N.; Menegazzo, R.; Neyens, G.; Pavan, P.; Rossi Alvarez, C.; Ur, C. A.; Vyvey, K.; Frauendorf, S.
2011-01-01
The spectroscopic quadrupole moment of the T1/2=9.4(5) ns isomer in Pb193 at an excitation energy Eex=(2585+x) keV is measured by the time-differential perturbed angular distribution method as |Qs|=2.6(3) e b. Spin and parity Iπ=27/2- are assigned to it based on angular distribution measurements. This state is the band head of a magnetic-rotational band, described by the 1i13/2 subshell with the (3s1/2-21h9/21i13/2)11- proton excitation. The pairing-plus-quadrupole tilted-axis cranking calculations reproduce the measured quadrupole moment with a moderate oblate deformation ɛ2=-0.11, similar to that of the 11-proton intruder states, which nuclei in the region. This is the first direct measurement of a quadrupole moment and thus of the deformation of a magnetic-rotational band head.
Spin, quadrupole moment, and deformation of the magnetic-rotational band head in (193)Pb
Balabanski, D L; Iordachescu, A; Bazzacco, D; Brandolini, F; Bucurescu, D; Chmel, S; Danchev, M; De Poli, M; Georgiev, G; Haas, H; Hubel, H; Marginean, N; Menegazzo, R; Neyens, G; Pavan, P; Rossi Alvarez, C; Ur, C A; Vyvey, K; Frauendorf, S
2011-01-01
The spectroscopic quadrupole moment of the T(1/2) = 9.4(5) ns isomer in (193)Pb at an excitation energy E(ex) = (2585 + x) keV is measured by the time-differential perturbed angular distribution method as vertical bar Q(s)vertical bar = 2.6(3) e b. Spin and parity I(pi) = 27/2(-) are assigned to it based on angular distribution measurements. This state is the band head of a magnetic-rotational band, described by the coupling of a neutron hole in the 1i(13/2) subshell with the (3s(1/2)(-2)1h(9/2)1i(13/2))(11-) proton excitation. The pairing-plus-quadrupole tilted-axis cranking calculations reproduce the measured quadrupole moment with a moderate oblate deformation epsilon(2) = -0.11, similar to that of the 11(-)proton intruder states, which occur in the even-even Pb nuclei in the region. This is the first direct measurement of a quadrupole moment and thus of the deformation of a magnetic-rotational band head.
Mosichkin, A. F.
2017-11-01
The process of radiative decay of the neutrino with a magnetic moment in a strong magnetic field with consideration of positronium influence on photon dispersion has been studied. Positronium contribution to the photon polarization operator induces significant modifications of the photon dispersion law and neutrino radiative decay amplitude. It has been shown that the mean energy loss of a neutrino with magnetic a moment significantly increases, when the positronium contribution to photon dispersion is taken into account.
2006-03-02
SUBTITLE Toward High Magnetic Moment, Controlled-Size, Blood Dispersible Nanoparticles: An Enabling Technology for Biomagnetics Interfacing...Dispersible Nanoparticles: An Enabling Technology for Biomagnetic Interfacing Concepts Final Report submitted to Dr. Hugh DeLong, AFOSR, and Dr
International Nuclear Information System (INIS)
Rijssel, Jos van; Kuipers, Bonny W.M.; Erné, Ben H.
2015-01-01
High-frequency applications of magnetic nanoparticles, such as therapeutic hyperthermia and magnetic particle imaging, are sensitive to nanoparticle size and dipole moment. Usually, it is assumed that magnetic nanoparticles with a log-normal distribution of the physical size also have a log-normal distribution of the magnetic dipole moment. Here, we test this assumption for different types of superparamagnetic iron oxide nanoparticles in the 5–20 nm range, by multimodal fitting of magnetization curves using the MINORIM inversion method. The particles are studied while in dilute colloidal dispersion in a liquid, thereby preventing hysteresis and diminishing the effects of magnetic anisotropy on the interpretation of the magnetization curves. For two different types of well crystallized particles, the magnetic distribution is indeed log-normal, as expected from the physical size distribution. However, two other types of particles, with twinning defects or inhomogeneous oxide phases, are found to have a bimodal magnetic distribution. Our qualitative explanation is that relatively low fields are sufficient to begin aligning the particles in the liquid on the basis of their net dipole moment, whereas higher fields are required to align the smaller domains or less magnetic phases inside the particles. - Highlights: • Multimodal fits of dilute ferrofluids reveal when the particles are multidomain. • No a priori shape of the distribution is assumed by the MINORIM inversion method. • Well crystallized particles have log-normal TEM and magnetic size distributions. • Defective particles can combine a monomodal size and a bimodal dipole moment
Spontaneous drainage in syringomyelia: magnetic resonance imaging findings
International Nuclear Information System (INIS)
Bogdanov, E.I.; Mendelevich, E.G.; Ibatullin, M.M.
2000-01-01
We present five cases of syringomyelia associated with Chiari I or other causes of partial obstructions at the cervicomedullary junction, with spontaneous disruption of the wall of a cervical syrinx and formation of a communication between the cavity and the subarachnoid space, shown on axial MRI. MRI can be used to investigate the hydrodynamics, showing the liquid inside the disrupted syrinx wall and the pathway of drainage. The finding of spontaneous drainage may be important for understanding the pathogenesis of syringomyelia and may be helpful for choosing a surgical approach. (orig.)
Temperature dependence of spin and orbital magnetic moments of Sm 4f electrons in (Sm, Gd)Al2
International Nuclear Information System (INIS)
Qiao, S.; Kimura, A.; Adachi, H.; Iori, K.; Miyamoto, K.; Xie, T.; Namatame, H.; Taniguchi, M.; Tanaka, A.; Muro, T.; Imada, S.; Suga, S.
2005-01-01
X-ray magnetic circular dichroism studies were carried out on (Sm, Gd)Al 2 , a ferromagnet without net magnetization at a certain compensation temperature. For Sm 4f electrons, the following understandings were obtained: the magnitude of expectation value of orbital magnetic moment (m L Sm ) is always larger than that of spin one (m S Sm ), so the cancellation of total spin and orbital magnetic moments cannot be achieved only by Sm 4f electrons and the contributions from Gd ions and conduction electrons are important; when the temperature decreases, the magnitude of both m L Sm and m S Sm increases and the gross magnetic moment due to the Sm 4f electrons monotonically deviates from zero. These results tell us that the temperature dependence of magnetic moments related with the electrons other than Sm 4f ones may play important roles in the subtle adjustment of the total spin and orbital magnetic moments to the zero magnetization at the compensation temperature
International Nuclear Information System (INIS)
Shimizu, T.; Kondoh, K.; Ugai, M.; Shibata, K.
2009-01-01
Three-dimensional instability of the spontaneous fast magnetic reconnection is studied with magnetohydrodynamic (MHD) simulation, where the two-dimensional model of the spontaneous fast magnetic reconnection is destabilized in three dimension. Generally, in two-dimensional magnetic reconnection models, every plasma condition is assumed to be uniform in the sheet current direction. In such two-dimensional MHD simulations, the current sheet destabilized by the initial resistive disturbance can be developed to fast magnetic reconnection by a current driven anomalous resistivity. In this paper, the initial resistive disturbance includes a small amount of fluctuations in the sheet current direction, i.e., along the magnetic neutral line. The other conditions are the same as that of previous two-dimensional MHD studies for fast magnetic reconnection. Accordingly, we may expect that approximately two-dimensional fast magnetic reconnection occurs in the MHD simulation. In fact, the fast magnetic reconnection activated on the first stage of the simulation is two dimensional. However, on the subsequent stages, it spontaneously becomes three dimensional and is strongly localized in the sheet current direction. The resulting three-dimensional fast magnetic reconnection intermittently ejects three-dimensional magnetic loops. Such intermittent ejections of the three-dimensional loops are similar to the intermittent downflows observed in the solar flares. The ejection of the three-dimensional loops seems to be random but, numerically and theoretically, it is shown that the aspect ratio of the ejected loops is limited under a criterion.
Determination of Local Magnetic Dipole Moment of the Plasma at the PUPR Cusp-Mirror Machine
International Nuclear Information System (INIS)
Leal-Quiros, Edbertho; Prelas, Mark
2006-01-01
A novel diagnostic that allows measurement of the magnetic moment μ has been designed. The μ-Analyzer consists of a Directional Energy Analyzer and a Magnetic Hall Probe in the same detector miniature case. The Directional Energy Analyzer measures the ion temperature in the perpendicular direction to the magnetic field. On the other side, the Hall Probe measures the magnetic field. The μ-Analyzer is a miniature analyzer to avoid plasma perturbation. This allows the measurement of the ion temperature and the local magnetic field at the same point at the same time, therefore μ, the first adiabatic invariant is found. From the above parameters, the local Larmor radius also will be calculated. From the analysis of the data simultaneously in time and space, the μ of the Local Plasma has been determined. This result is a very important quantity, among other properties that permit one to know the stability of the magnetic confinement device using the MHD Stability Criterium, and also very important in Space Plasma Research. In addition to the above, a direct measurement of the Larmor radius of each position is also possible. The experiments have been made in a Cusp/Mirror Plasma Machine where plasma parameters such as Density and Temperature are relatively easy to change in a very wide range
New Nuclear Magnetic Moment of 209Bi: Resolving the Bismuth Hyperfine Puzzle
Skripnikov, Leonid V.; Schmidt, Stefan; Ullmann, Johannes; Geppert, Christopher; Kraus, Florian; Kresse, Benjamin; Nörtershäuser, Wilfried; Privalov, Alexei F.; Scheibe, Benjamin; Shabaev, Vladimir M.; Vogel, Michael; Volotka, Andrey V.
2018-03-01
A recent measurement of the hyperfine splitting in the ground state of Li-like 80+208Bi has established a "hyperfine puzzle"—the experimental result exhibits a 7 σ deviation from the theoretical prediction [J. Ullmann et al., Nat. Commun. 8, 15484 (2017), 10.1038/ncomms15484; J. P. Karr, Nat. Phys. 13, 533 (2017), 10.1038/nphys4159]. We provide evidence that the discrepancy is caused by an inaccurate value of the tabulated nuclear magnetic moment (μI) of 209Bi. We perform relativistic density functional theory and relativistic coupled cluster calculations of the shielding constant that should be used to extract the value of μI(209ipts>) and combine it with nuclear magnetic resonance measurements of Bi (NO3 )3 in nitric acid solutions and of the hexafluoridobismuthate(V) BiF6- ion in acetonitrile. The result clearly reveals that μI(209Bi) is much smaller than the tabulated value used previously. Applying the new magnetic moment shifts the theoretical prediction into agreement with experiment and resolves the hyperfine puzzle.
Tilted-foil polarisation and magnetic moments of mirror nuclei at ISOLDE
Bordeanu, C; Thundiyamkulathu Baby, L; Lindroos, M
2002-01-01
We report here on the first measurement in an experimental program initiated at the ISOLDE facility at CERN for the measurement of magnetic moments of short-lived radionuclides. The 60~keV ISOLDE beam from the GPS separator is boosted in energy by a 200~kV high-voltage platform, on which the whole experiment is mounted, in order to achieve sufficiently high energy for transmission through the foils of a tilted-foil setup. The 520~keV $^{23}$Mg(2$^+$) nuclei are polarized by the tilted foil technique and the resulting 0$^o$ - 180$^o$ $\\beta$- asymmetry is monitored as a function of the frequency of an rf-applied perturbing magnetic field in an NMR setup.\\\\ In this experiment, earlier asymmetry measurements were confirmed and an NMR resonance was observed, corresponding to a preliminary value of the magnetic moment of 0.533(6) n.m., in agreement with a previous measurement. The measured asymmetry as function of NMR frequency and the fitted resonance curve are presented in the figure. During the e...
Deák, A.; Simon, E.; Balogh, L.; Szunyogh, L.; dos Santos Dias, M.; Staunton, J. B.
2014-06-01
We develop a self-consistent relativistic disordered local moment (RDLM) scheme aimed at describing finite-temperature magnetism of itinerant metals from first principles. Our implementation in terms of the Korringa-Kohn-Rostoker multiple-scattering theory and the coherent potential approximation allows us to relate the orientational distribution of the spins to the electronic structure, thus a self-consistent treatment of the distribution is possible. We present applications for bulk bcc Fe, L10-FePt, and FeRh ordered in the CsCl structure. The calculations for Fe show significant variation of the local moments with temperature, whereas according to the mean-field treatment of the spin fluctuations the Curie temperature is overestimated. The magnetic anisotropy of FePt alloys is found to depend strongly on intermixing between nominally Fe and Pt layers, and it shows a power-law behavior as a function of magnetization for a broad range of chemical disorder. In the case of FeRh we construct a lattice constant vs temperature phase diagram and determine the phase line of metamagnetic transitions based on self-consistent RDLM free-energy curves.
Modulating spontaneous brain activity using repetitive transcranial magnetic stimulation
van der Werf, Y.D.; Sanz-Arigita, E.J.; Menning, S.; van den Heuvel, O.A.
2010-01-01
Background: When no specific stimulus or task is presented, spontaneous fluctuations in brain activity occur. Brain regions showing such coherent fluctuations are thought to form organized networks known as 'resting-state' networks, a main representation of which is the default mode network.
Development of low background germanium spectrometer for measurement of neutrino magnetic moment
Beda, A G; Starostin, A S
2000-01-01
The prospects for a search for neutrino magnetic moment down to (3-5)centre dot 10 sup - sup 1 sup 1 of the Bohr magneton with the use of low background Ge-NaI spectrometer built in ITEP are discussed. The lowest level of background for shallow setups was achieved in the preliminary test measurements of background. This result and estimations of additional sources of the background in a reactor experiment testify that using the low background Ge-NaI spectrometer with mass of Ge-crystal of 2 kg it is possible to achieve above objective, that will be one order of magnitude better than the present experimental limit.
Mind the Gap on IceCube: Cosmic neutrino spectrum and muon anomalous magnetic moment
Araki, T.; Kaneko, F.; Konishi, Y.; Ota, T.; Sato, J.; Shimomura, T.
2017-09-01
The high energy cosmic neutrino spectrum reported by the IceCube collaboration shows a gap in the energy range between 500 TeV and 1 PeV. In this presentation, we illustrate that the IceCube gap is reproduced by the neutrino interaction mediated by the new gauge boson associated with a certain combination of the lepton avour number. The gauge interaction also explains the other long-standing gap in the lepton phenomenology: the gap between theory and experiment in the muon anomalous magnetic moment.
Maslov, S. A.; Bobrov, V. B.; Kirillin, A. V.; Trigger, S. A.
2018-01-01
Using the linear response theory, the transverse dielectric permittivity of a homogeneous and isotropic system of charged particles is considered. In the ideal gas approximation for the polarization function, an explicit analytical expression for the transverse permittivity of a degenerate electron plasma, which takes into account electron spin, is found. This result describes both the Landau diamagnetism and Pauli paramagnetism in electron plasma. The influence of the electron intrinsic magnetic moment on the spatial and frequency dispersion of the transverse dielectric permittivity of degenerate electron plasma is numerically studied, that is crucial for determining the optical characteristics of plasma.
Ab initio Disordered Local Moment Approach for a Doped Rare-Earth Magnet
Matsumoto, Munehisa; Banerjee, Rudra; Staunton, Julie B.
Following the finite-temperature ab initio calculation framework based on the relativistic disordered local moments [J. B. Staunton et al., Phys. Rev. Lett. 93, 257204 (2004); Phys. Rev. B 74, 144411 (2006)], we computationally demonstrate the possibility of doping-enhanced coercivity at high-temperatures, taking YCo5 as a working material in order to extract the 3d-electron part of the electronic structure of the rare-earth permanent magnets. Alkaline-earth dopants are shown to be the candidates to realize the proposed phenomenon.
Blum, T; Boyle, P A; Izubuchi, T; Jin, L; Jüttner, A; Lehner, C; Maltman, K; Marinkovic, M; Portelli, A; Spraggs, M
2016-06-10
We report the first lattice QCD calculation of the hadronic vacuum polarization (HVP) disconnected contribution to the muon anomalous magnetic moment at physical pion mass. The calculation uses a refined noise-reduction technique that enables the control of statistical uncertainties at the desired level with modest computational effort. Measurements were performed on the 48^{3}×96 physical-pion-mass lattice generated by the RBC and UKQCD Collaborations. We find the leading-order hadronic vacuum polarization a_{μ}^{HVP(LO)disc}=-9.6(3.3)(2.3)×10^{-10}, where the first error is statistical and the second systematic.
A CF4 TPC to measure the ν-bare magnetic moment at a nuclear reactor
International Nuclear Information System (INIS)
Broggini, C.; Joergens, V.; Treichel, M.; Twerenbold, D.; Vuilleumier, J.L.
1992-01-01
An experiment is described which offers a significant improvement for the measurement of the ν-bar e e - cross section at low energy. The experiment will be sensitive to a neutrino magnetic moment down to a few 10 -11 Bohr magnetons, on the level of that introduced to explain the solar neutrino puzzle. The detector, to be placed close to a nuclear reactor, is a 1 m 3 Time Projection Chamber surrounded by an active shielding. The key point of the experiment is the use of tetrafluoromethane, CF 4 , at the pressure of 5 bar in the TPC. (author) 10 refs.; 1 tab
Higher-order hadronic and heavy-lepton contributions to the anomalous magnetic moment
International Nuclear Information System (INIS)
Kurz, Alexander; Liu, Tao; Steinhauser, Matthias
2014-07-01
We report about recent results obtained for the muon anomalous magnetic moment. Three-loop kernel functions have been computed to obtain the next-to-next-to-leading-order hadronic vacuum polarization contributions. The numerical result, a μ had,NNLO = 1.24 ± 0.01 x 10 -10 , is of the same order of magnitude as the current uncertainty from the hadronic contributions. For heavy-lepton corrections, analytical results are obtained at four-loop order and compared with the known results.
Directed magnetic field induced assembly of high magnetic moment cobalt nanowires
DEFF Research Database (Denmark)
Srivastava, Akhilesh Kumar; Madhavi, S.; Ramanujan, R.V.
2010-01-01
A directed magnetic field induced assembly technique was employed to align two phase (h.c.p. + f.c.c.) cobalt nanoparticles in a mechanically robust long wire morphology. Co nanoparticles with an average size of 4.3 nm and saturation magnetization comparable to bulk cobalt were synthesized...
Room-temperature ferromagnetism with high magnetic moment in Cu-doped AlN single crystal whiskers
Jiang, Liang-Bao; Liu, Yu; Zuo, Si-Bin; Wang, Wen-Jun
2015-02-01
Ferromagnetism is investigated in high-quality Cu-doped AlN single crystal whiskers. The whiskers exhibit room-temperature ferromagnetism with a magnetic moment close to the results from first-principles calculations. High crystallinity and low Cu concentrations are found to be indispensable for high magnetic moments. The difference between the experimental and theoretical moment values is explored in terms of the influence of nitrogen vacancies. The calculated results demonstrate that nitrogen vacancies can reduce the magnetic moments of Cu atom. Project supported by the National Basic Research Program of China (Grant No. 2013CB932901), the National Natural Science Foundation of China (Grant Nos. 51372267, 51210105026, and 51172270), the Funds from the Chinese Academy of Sciences, the International Centre for Diffraction Data, USA (2013 Ludo Frevel Crystallography Scholarship Award), and the Funds from the Ministry of Education of China (2012 Academic Scholarship Award for Doctoral Candidates).
Wilhelm, F.; Sanchez, J. P.; Brison, J.-P.; Aoki, D.; Shick, A. B.; Rogalev, A.
2017-06-01
The ferromagnetic superconductor URhGe has been investigated by high field magnetic circular dichroism (XMCD) at the U M4 ,5, Rh L2 ,3, and Ge K edges at 2.1 K and at applied fields up to 17 T. The XMCD performed at the M4 ,5 absorption edges allows us to determine the spectroscopic branching ratio and the 5 f electron contribution to the valence spin-orbit interaction. Combination with polarized neutron diffraction results allows us to derive the individual U orbital and spin moments and the magnetic-dipole contribution . There is no evidence for any change of the orbital-to-spin moment ratios across the spin reorientation transition at HR=12 T , when the field is applied along the initial hard b axis. We also confirm that the magnetism of URhGe is dominated by U , with the contribution of Rh representing only about 10 % of the macroscopic moment. The orbital and spin moments at the Rh site are found to be parallel to each other and parallel to the macroscopic magnetization, but an unexpectedly large orbital-to-spin moment ratio is observed. The XMCD at the Ge K edge reveals the presence of a small induced Ge 4 p orbital moment, parallel to the macroscopic magnetization. The results are discussed against predictions of the electronic band structure calculations by the density functional theory plus Coulomb U , including spin-orbit coupling (DFT +U +SOC ) .
de Melo, Roger Duarte; Acosta-Avalos, Daniel
2017-09-01
Magnetotactic microorganisms are characterized by swimming in the direction of an applied magnetic field. In nature, two types of swimming polarity have been observed: north-seeking microorganisms that swim in the same direction as the magnetic field, and south-seeking microorganisms that swim in the opposite direction. The present work studies the reversal in the swimming polarity of the multicellular magnetotactic prokaryote Candidatus Magnetoglobus multicellularis following an isolation process using high magnetic fields from magnets. The proportion of north- and south-seeking organisms was counted as a function of the magnetic field intensity used during the isolation of the organisms from sediment. It was observed that the proportion of north-seeking organisms increased when the magnetic field was increased. The magnetic moment for north- and south-seeking populations was estimated using the U-turn method. The average magnetic moment was higher for north- than south-seeking organisms. The results suggest that the reversal of swimming polarity must occur during the isolation process in the presence of high magnetic fields and magnetic field gradients. It is shown for the first time that the swimming polarity reversal depends on the magnetic moment intensity of multicellular magnetotactic prokaryotes, and new studies must be undertaken to understand the role of magnetic moment polarity and oxygen gradients in determination of swimming polarity.
Anomalous properties of a large magnetic moment in a fourfold potential
Vernier, N
2003-01-01
An experimental study of magnetic moments placed in a fourfold potential is presented here. The system used is a monocrystal of LiY sub 0 sub . sub 9 sub 9 Dy sub 0 sub . sub 0 sub 1 F sub 4 , where the only magnetic ions are the Dy sup 3 sup + ions. From static magnetic susceptibility measurements, it is shown that the Dy sup 3 sup + ion has an easy magnetization plane, with an additional anisotropy in the easy plane. Low frequency electron paramagnetic resonance experiments are presented here and up to nine resonance lines have been found. Some of them are in agreement with known properties of the Dy sup 3 sup + ion in LiY sub 0 sub . sub 9 sub 9 Dy sub 0 sub . sub 0 sub 1 F sub 4 , but others cannot be explained within the framework of the commonly used effective Hamiltonian. The behaviour of these new lines is consistent with a magnetic tunnelling effect. Finally, spin echoes have been observed, allowing the determination of the relaxation time T sub 2 and the coupling coefficient for several orientations...
International Nuclear Information System (INIS)
Kozlov, A.N.; Nikitenko, Yu.V.; Taran, Yu.V.
1980-01-01
A two-cascade magnetic field stabilizer of installation for the measurement of neutron electrjcal dipole moment (EDM) using ultracold neutrons has been constructed and tested. Quantum cesium magnetometers (QCM) with optical pumping placed inside a ferromagnetic screen were used as primary convertors of the magnetic field. A stabilization coefficient of 4x10 5 in a bandwidth of 10 -3 -3x10 -3 Hz in the presence of magnetic noise of an amplitude up to 50 nT was obtained using QCM with Ssub(Z)-signal in the inner and outer cascades having transfer ratios of 300 and 600, respectively. Mean square amplitude of magnetic field fluctuations was below 0.O5 pT. Stabilization in a wider frequency band was performed using QCM with Ssub(Z)-signal in the inner cascade and QCM with Ssub(X)-signal in the outer cascade. In particular, the mean square amplitude of magnetic field fluctuations within a bandwidth of 0.1-1 Hz and 1-10 Hz was below 1 nT and 15 nT respectively
International Nuclear Information System (INIS)
Wang, Liang; Germaschewski, K.; Hakim, Ammar H.; Bhattacharjee, A.
2015-01-01
We introduce an extensible multi-fluid moment model in the context of collisionless magnetic reconnection. This model evolves full Maxwell equations and simultaneously moments of the Vlasov-Maxwell equation for each species in the plasma. Effects like electron inertia and pressure gradient are self-consistently embedded in the resulting multi-fluid moment equations, without the need to explicitly solving a generalized Ohm's law. Two limits of the multi-fluid moment model are discussed, namely, the five-moment limit that evolves a scalar pressures for each species and the ten-moment limit that evolves the full anisotropic, non-gyrotropic pressure tensor for each species. We first demonstrate analytically and numerically that the five-moment model reduces to the widely used Hall magnetohydrodynamics (Hall MHD) model under the assumptions of vanishing electron inertia, infinite speed of light, and quasi-neutrality. Then, we compare ten-moment and fully kinetic particle-in-cell (PIC) simulations of a large scale Harris sheet reconnection problem, where the ten-moment equations are closed with a local linear collisionless approximation for the heat flux. The ten-moment simulation gives reasonable agreement with the PIC results regarding the structures and magnitudes of the electron flows, the polarities and magnitudes of elements of the electron pressure tensor, and the decomposition of the generalized Ohm's law. Possible ways to improve the simple local closure towards a nonlocal fully three-dimensional closure are also discussed
Influence of magnetic moment formation on the conductance of coupled quantum wires
International Nuclear Information System (INIS)
Puller, V I; Mourokh, L G; Bird, J P; Ochiai, Y
2005-01-01
In this paper, we develop a model for the resonant interaction between a pair of coupled quantum wires, under conditions where self-consistent effects lead to the formation of a local magnetic moment in one of the wires. Our analysis is motivated by the experimental results of Morimoto et al (2003 Appl. Phys. Lett. 82 3952), who showed that the conductance of one of the quantum wires exhibits a resonant peak at low temperatures, whenever the other wire is swept into the regime where local-moment formation is expected. In order to account for these observations, we develop a theoretical model for the inter-wire interaction that calculated the transmission properties of one (the fixed) wire when the device potential is modified by the presence of an extra scattering term, arising from the presence of the local moment in the swept wire. To determine the transmission coefficients in this system, we derive equations describing the dynamics of electrons in the swept and fixed wires of the coupled-wire geometry. Our analysis clearly shows that the observation of a resonant peak in the conductance of the fixed wire is correlated to the appearance of additional structure (near 0.75 x 2e 2 /h or 0.25 x 2e 2 /h) in the conductance of the swept wire, in agreement with the experimental results of Morimoto et al
Staunton, Julie B.; Marmodoro, Alberto; Ernst, Arthur
2014-07-01
We briefly describe the density functional theory (DFT)-based ‘disordered local moment’ (DLM) picture for magnetism at finite temperatures. It shows how relatively slowly fluctuating local moments can emerge from the interacting electrons of many materials. Such entities have rigid magnitudes and fluctuate their orientations from atomic site to atomic site on a timescale long compared to other electronic times. We illustrate this theory with calculations of the magnetocaloric effect in Gd where we find excellent agreement with experiments. Fluctuating moments do not appear to establish naturally over such small regions for some other materials. We show how the DFT-DLM theory can be extended to these materials with the use of the Korringa-Kohn-Rostoker nonlocal coherent potential approximation (KKR-NLCPA) to allow for more extensive, slow magnetic fluctuations. We present the first application of this approach by revisiting the description of the magnetic fluctuations prevalent in the paramagnetic state of nickel. We find that local moments can emerge above Tc and that these form coherently over small clumps of atomic sites (4-8 sites).
Hyperfine structure, nuclear spins and magnetic moments of some cesium isotopes
International Nuclear Information System (INIS)
Ekstroem, C.; Ingelman, S.; Wannberg, G.
1977-03-01
Using an atomic-beam magnetic resonance apparatus connected on-line with the ISOLDE isotope separator, CERN, hyperfine structure measurements have been performed in the 2 Ssub(1/2) electronic ground state of some cesium isotopes. An on-line oven system which efficiently converts a mass separated ion-beam of alkali isotopes to an atomic beam is described in some detail. Experimentally determined nuclear spins of sup(120, 121, 121m, 122, 122m, 123, 124, 126, 128, 130m, 135m)Cs and magnetic moments of sup(122, 123, 124, 126, 128, 130)Cs are reported and discussed in terms of different nuclear models. The experimental data indicate deformed nuclear shapes of the lightest cesium isotopes. (Auth.)
Non-Fermi-Liquid Behavior in Metallic Quasicrystals with Local Magnetic Moments
Andrade, Eric C.; Jagannathan, Anuradha; Miranda, Eduardo; Vojta, Matthias; Dobrosavljević, Vladimir
2015-07-01
Motivated by the intrinsic non-Fermi-liquid behavior observed in the heavy-fermion quasicrystal Au51Al34Yb15 , we study the low-temperature behavior of dilute magnetic impurities placed in metallic quasicrystals. We find that a large fraction of the magnetic moments are not quenched down to very low temperatures T , leading to a power-law distribution of Kondo temperatures P (TK)˜TKα -1, with a nonuniversal exponent α , in a remarkable similarity to the Kondo-disorder scenario found in disordered heavy-fermion metals. For α <1 , the resulting singular P (TK) induces non-Fermi-liquid behavior with diverging thermodynamic responses as T →0 .
Application of transient magnetic field to the measurement of nuclear magnetic moments
International Nuclear Information System (INIS)
Ribas, R.V.
1987-01-01
A review on: the mechanism for producing transient magnetic field; techniques for measuring nuclear gyromagnetic factor; and some examples of recent measurements using this technique is presented. (M.C.K.) [pt
[Multiple coil pulsed magnetic resonance method to measure the SSC bending magnet multipole moments
International Nuclear Information System (INIS)
Clark, W.G.
1990-01-01
The main emphasis has been to continue development of the high frequency (to 300 MHz) instrumentation, to test the system on a prototype bending magnet, construct the high frequency 32-channel electronics and probes, to seek industrial partners for technology transfer and commercial exploitation, and to do computer simulations for optimizing design parameters. Experience gained from tests made on a dipole magnet at Lawrence Berkeley Laboratory was extremely valuable and has resulted in substantial modifications to the original design
A parts-per-billion measurement of the antiproton magnetic moment
Smorra, C; Borchert, M J; Harrington, J A; Higuchi, T; Nagahama, H; Tanaka, T; Mooser, A; Schneider, G; Blaum, K; Matsuda, Y; Ospelkaus, C; Quint, W; Walz, J; Yamazaki, Y; Ulmer, S
2016-01-01
Precise comparisons of the fundamental properties of matter–antimatter conjugates provide sensitive tests of charge–parity–time (CPT) invariance1, which is an important symmetry that rests on basic assumptions of the standard model of particle physics. Experiments on mesons2, leptons3, 4 and baryons5, 6 have compared different properties of matter–antimatter conjugates with fractional uncertainties at the parts-per-billion level or better. One specific quantity, however, has so far only been known to a fractional uncertainty at the parts-per-million level7, 8: the magnetic moment of the antiproton, . The extraordinary difficulty in measuring with high precision is caused by its intrinsic smallness; for example, it is 660 times smaller than the magnetic moment of the positron3. Here we report a high-precision measurement of in units of the nuclear magneton μN with a fractional precision of 1.5 parts per billion (68% confidence level). We use a two-particle spectroscopy method in an advanced cryogenic ...
Blum, Thomas; Chowdhury, Saumitra; Hayakawa, Masashi; Izubuchi, Taku
2015-01-09
The most compelling possibility for a new law of nature beyond the four fundamental forces comprising the standard model of high-energy physics is the discrepancy between measurements and calculations of the muon anomalous magnetic moment. Until now a key part of the calculation, the hadronic light-by-light contribution, has only been accessible from models of QCD, the quantum description of the strong force, whose accuracy at the required level may be questioned. A first principles calculation with systematically improvable errors is needed, along with the upcoming experiments, to decisively settle the matter. For the first time, the form factor that yields the light-by-light scattering contribution to the muon anomalous magnetic moment is computed in such a framework, lattice QCD+QED and QED. A nonperturbative treatment of QED is used and checked against perturbation theory. The hadronic contribution is calculated for unphysical quark and muon masses, and only the diagram with a single quark loop is computed for which statistically significant signals are obtained. Initial results are promising, and the prospect for a complete calculation with physical masses and controlled errors is discussed.
Matsumoto, Munehisa; Banerjee, Rudra; Staunton, Julie B.
2014-08-01
Temperature dependence of the magnetocrystalline anisotropy energy and magnetization of the prototypical rare-earth magnet YCo5 is calculated from first principles, utilizing the relativistic disordered local-moment approach. We discuss a strategy to enhance the finite-temperature anisotropy field by hole doping, paving the way for an improvement of the coercivity near room temperature or higher.
Rashba Interaction and Local Magnetic Moments in a Graphene-BN Heterostructure Intercalated with Au
O'Farrell, E. C. T.; Tan, J. Y.; Yeo, Y.; Koon, G. K. W.; Ã-zyilmaz, B.; Watanabe, K.; Taniguchi, T.
2016-08-01
We intercalate a van der Waals heterostructure of graphene and hexagonal boron nitride with Au, by encapsulation, and show that the Au at the interface is two dimensional. Charge transfer upon current annealing indicates the redistribution of the Au and induces splitting of the graphene band structure. The effect of an in-plane magnetic field confirms that the splitting is due to spin splitting and that the spin polarization is in the plane, characteristic of a Rashba interaction with a magnitude of approximately 25 meV. Consistent with the presence of an intrinsic interfacial electric field we show that the splitting can be enhanced by an applied displacement field in dual gated samples. A giant negative magnetoresistance, up to 75%, and a field induced anomalous Hall effect at magnetic fields <1 T are observed. These demonstrate that the hybridized Au has a magnetic moment and suggests the proximity to the formation of a collective magnetic phase. These effects persist close to room temperature.
Energy Technology Data Exchange (ETDEWEB)
Arroyo-Urena, M.A.; Tavares-Velasco, G. [Benemerita Universidad Autonoma de Puebla, Facultad de Ciencias Fisico-Matematicas, Puebla, PUE (Mexico); Hernandez-Tome, G. [Benemerita Universidad Autonoma de Puebla, Facultad de Ciencias Fisico-Matematicas, Puebla, PUE (Mexico); Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional, Departamento de Fisica, Mexico City (Mexico)
2017-04-15
We obtain analytical expressions, both in terms of parametric integrals and Passarino-Veltman scalar functions, for the one-loop contributions to the anomalous weak magnetic dipole moment (AWMDM) of a charged lepton in the framework of the simplest little Higgs model (SLHM). Our results are general and can be useful to compute the weak properties of a charged lepton in other extensions of the standard model (SM). As a by-product we obtain generic contributions to the anomalous magnetic dipole moment (AMDM), which agree with previous results. We then study numerically the potential contributions from this model to the τ lepton AMDM and AWMDM for values of the parameter space consistent with current experimental data. It is found that they depend mainly on the energy scale f at which the global symmetry is broken and the t{sub β} parameter, whereas there is little sensitivity to a mild change in the values of other parameters of the model. While the τ AMDM is of the order of 10{sup -9}, the real (imaginary) part of its AWMDM is of the order of 10{sup -9} (10{sup -10}). These values seem to be out of the reach of the expected experimental sensitivity of future experiments. (orig.)
Haldar, Soumyajyoti
2014-05-09
In this work, we have studied the chemical and magnetic interactions of Fen (n=1–6) clusters with vacancy defects (monovacancy to correlated vacancies with six missing C atoms) in a graphene sheet by ab initio density functional calculations combined with Hubbard U corrections for correlated Fe-d electrons. It is found that the vacancy formation energies are lowered in the presence of Fe, indicating an easier destruction of the graphene sheet. Due to strong chemical interactions between Fe clusters and vacancies, a complex distribution of magnetic moments appear on the distorted Fe clusters which results in reduced averaged magnetic moments compared to the free clusters. In addition to that, we have calculated spin-dipole moments and magnetic anisotropy energies. The calculated spin-dipole moments arising from anisotropic spin density distributions vary between positive and negative values, yielding increased or decreased effective moments. Depending on the cluster geometry, the easy axis of magnetization of the Fe clusters shows in-plane or out-of-plane behavior.
Energy Technology Data Exchange (ETDEWEB)
Aliev, T.M., E-mail: taliev@metu.edu.t [Physics Department, Middle East Technical University, 06531 Ankara (Turkey); Azizi, K., E-mail: kazizi@dogus.edu.t [Physics Division, Faculty of Arts and Sciences, Dogus University, Acibadem-Kadikoey, 34722 Istanbul (Turkey); Savci, M., E-mail: savci@metu.edu.t [Physics Department, Middle East Technical University, 06531 Ankara (Turkey)
2009-11-02
The electric quadrupole and magnetic octupole moments of the light decuplet baryons are calculated in the framework of the light cone QCD sum rules. The obtained non-vanishing values for the electric quadrupole and magnetic octupole moments of these baryons show nonspherical charge distribution. The sign of electric quadrupole moment is positive for OMEGA{sup -}, XI*{sup -}, SIGMA*{sup -} and negative for SIGMA*{sup +}, which correspond to the prolate and oblate charge distributions, respectively. A comparison of the obtained results with the predictions of non-covariant quark model which shows a good consistency between two approaches is also presented. Comparison of the obtained results on the multipole moments of the decuplet baryons containing strange quark with those of DELTA baryons shows a large SU(3) flavor symmetry breaking.
Fradin, Cécile
2013-01-01
Magnetotactic bacteria possess organelles called magnetosomes that confer a magnetic moment on the cells, resulting in their partial alignment with external magnetic fields. Here we show that analysis of the trajectories of cells exposed to an external magnetic field can be used to measure the average magnetic dipole moment of a cell population in at least five different ways. We apply this analysis to movies of Magnetospirillum magneticum AMB-1 cells, and compare the values of the magnetic moment obtained in this way to that obtained by direct measurements of magnetosome dimension from electron micrographs. We find that methods relying on the viscous relaxation of the cell orientation give results comparable to that obtained by magnetosome measurements, whereas methods relying on statistical mechanics assumptions give systematically lower values of the magnetic moment. Since the observed distribution of magnetic moments in the population is not sufficient to explain this discrepancy, our results suggest that non-thermal random noise is present in the system, implying that a magnetotactic bacterial population should not be considered as similar to a paramagnetic material. PMID:24349185
Directory of Open Access Journals (Sweden)
Rohan Nadkarni
Full Text Available Magnetotactic bacteria possess organelles called magnetosomes that confer a magnetic moment on the cells, resulting in their partial alignment with external magnetic fields. Here we show that analysis of the trajectories of cells exposed to an external magnetic field can be used to measure the average magnetic dipole moment of a cell population in at least five different ways. We apply this analysis to movies of Magnetospirillum magneticum AMB-1 cells, and compare the values of the magnetic moment obtained in this way to that obtained by direct measurements of magnetosome dimension from electron micrographs. We find that methods relying on the viscous relaxation of the cell orientation give results comparable to that obtained by magnetosome measurements, whereas methods relying on statistical mechanics assumptions give systematically lower values of the magnetic moment. Since the observed distribution of magnetic moments in the population is not sufficient to explain this discrepancy, our results suggest that non-thermal random noise is present in the system, implying that a magnetotactic bacterial population should not be considered as similar to a paramagnetic material.
International Nuclear Information System (INIS)
Artru, X.; Fayolle, D.
2001-01-01
For a monopole, the analogue of the Lorentz equation in matter is shown to be f = g (H-v centre dot D). Dual-symmetric Maxwell equations, for matter containing hidden magnetic charge in addition to electric ones, are given. They apply as well to ordinary matter if the particles possess T-violating electric dipole moments. Two schemes of experiments for the detection of such moments in macroscopic pieces of matter are proposed
Magnetic moment of solar plasma and the Kelvin force: -The driving force of plasma up-flow -
Shibasaki, Kiyoto
2017-04-01
Thermal plasma in the solar atmosphere is magnetized (diamagnetic). The magnetic moment does not disappear by collisions because complete gyration is not a necessary condition to have magnetic moment. Magnetized fluid is subjected to Kelvin force in non-uniform magnetic field. Generally, magnetic field strength decreases upwards in the solar atmosphere, hence the Kelvin force is directed upwards along the field. This force is not included in the fluid treatment of MHD. By adding the Kelvin force to the MHD equation of motion, we can expect temperature dependent plasma flows along the field which are reported by many observations. The temperature dependence of the flow speed is explained by temperature dependence of magnetic moment. From the observed parameters, we can infer physical parameters in the solar atmosphere such as scale length of the magnetic field strength and the friction force acting on the flowing plasma. In case of closed magnetic field lines, loop-top concentration of hot plasma is expected which is frequently observed.
Multiple coil pulsed magnetic resonance method to measure the SSC bending magnet multipole moments
International Nuclear Information System (INIS)
Clark, W.G.
1990-01-01
This document describes the technical progress made during the current contract period (4-1-89 to 3-31-90) of US DOE Contract AC02-87ER40350. The main emphasis of the current contract year has been to continue development of the high frequency (to 300 MHz) instrumentation, to test the system on a prototype bending magnet, to construct the high frequency 32-channel electronics and probes, and to do computer simulations for optimizing design parameters. Experience gained from tests made on a dipole magnet at Lawrence Berkeley Laboratory was extremely valuable and has resulted in substantial modifications to the original designs. These, and other items are discussed in this paper
Spontaneous resorption of a herniated cervical disc in a dog detected by magnetic resonance imaging.
Raimondi, Francesca; Moreno-Aguado, Beatriz; Witte, Phil; Shihab, Nadia
2017-08-01
This report describes, for the first time in small animal literature, the spontaneous resorption of herniated Hansen type I intervertebral disc material in the cervical spine of a chondrodystrophic dog over a 4-month period, documented by magnetic resonance imaging. Clinical signs (cervical hyperpathia) responded to conservative treatment during the same period.
Nuclear magnetic moment of 69As from on-line β-NMR on oriented nuclei
International Nuclear Information System (INIS)
Golovko, V.V.; Kraev, I.S.; Phalet, T.; Severijns, N.; Delaure, B.; Beck, M.; Kozlov, V.Yu.; Lindroth, A.; Coeck, S.; Zakoucky, D.; Venos, D.; Srnka, D.; Honusek, M.; Herzog, P.; Tramm, C.; Koester, U.
2005-01-01
A precise value for the magnetic moment of the 69 As 5/2 - ground state has been obtained from nuclear magnetic resonance on oriented nuclei (NMR/ON) using the NICOLE 3 He- 4 He dilution refrigerator setup at ISOLDE/CERN. The NMR/ON signal was observed by monitoring the anisotropy of the 69 As β particles. The center frequency ν[B ext =0.0994(10)T]=169.98(9) MHz corresponds to μ[ 69 As]=+1.6229(16)μ N . This result differs considerably from the πf 5/2 single-particle value obtained with g factors for a free proton but is in reasonable agreement with the value obtained with effective g factors and with values from a core polarization calculation and from calculations in the framework of the interacting boson-fermion model. Assuming a single exponential spin-lattice relaxation behavior a relaxation time T 1 ' =10(25) s was observed for 69 AsFe -bar at a temperature of about 20 mK in a magnetic field B=0.1 T
Covariant Spectator Theory of np scattering: Deuteron magnetic moment and form factors
Energy Technology Data Exchange (ETDEWEB)
Gross, Franz L. [JLAB
2014-06-01
The deuteron magnetic moment is calculated using two model wave functions obtained from 2007 high precision fits to $np$ scattering data. Included in the calculation are a new class of isoscalar $np$ interaction currents which are automatically generated by the nuclear force model used in these fits. After normalizing the wave functions, nearly identical predictions are obtained: model WJC-1, with larger relativistic P-state components, gives 0.863(2), while model WJC-2 with very small $P$-state components gives 0.864(2) These are about 1\\% larger than the measured value of the moment, 0.857 n.m., giving a new prediction for the size of the $\\rho\\pi\\gamma$ exchange, and other purely transverse interaction currents that are largely unconstrained by the nuclear dynamics. The physical significance of these results is discussed, and general formulae for the deuteron form factors, expressed in terms of deuteron wave functions and a new class of interaction current wave functions, are given.
The dependence of magnetosphere-ionosphere system on the Earth's magnetic dipole moment
Ngwira, C. M.; Pulkkinen, A. A.; Sibeck, D. G.; Rastaetter, L.
2017-12-01
Space weather is increasingly recognized as an international problem affecting several different man-made technologies. The ability to understand, monitor and forecast Earth-directed space weather is of paramount importance for our highly technology-dependent society and for the current rapid developments in awareness and exploration within the heliosphere. It is well known that the strength of the Earth's magnetic field changes over long time scales. We use physics-based simulations with the University of Michigan Space Weather Modeling Framework (SWMF) to examine how the magnetosphere, ionosphere, and ground geomagnetic field perturbations respond as the geomagnetic dipole moment changes. We discuss the implication of these results for our community and the end-users of space weather information.
International Nuclear Information System (INIS)
Raszillier, I.
1977-06-01
The possible values of the pion charge radius rsub(π) are correlated with those of the pionic contribution asub(μ)(π + π - ) to the muon magnetic moment in terms of the normalization of the pion form factor, its modulus on part of the unitarity cut, and the quality of the chisup(2)-fit to values measured for it in a number of spacelike points. The correlation is expressed as a 3-dimensional set (D) of values (h'(0),||h||sup(2),chi) allowed for the functions h(z) analytic in the unit disk and belonging to a set Ω in the Hilbert space Hsup(2). The set D, which depends through Ω and chi on the information used, has simple convexity properties. Its computation is reduced to a problem of finite-dimensional convex optimization. (author)
International Nuclear Information System (INIS)
Aistov, A.V.; Gavrilenko, V.G.
1996-01-01
The normal incidence of a small-amplitude electromagnetic wave upon a semi-infinite turbulent collisional plasm with an oblique external magnetic field is considered. Within a small-angle-scattering approximation of the radiative transport theory, a system of differential equations is derived for statistical moments of the angular power spectrum of radiation. The dependences of the spectrum centroid, dispersion, and asymmetry on the depth of penetration are studied numerically. The nonmonotonic behavior of the dispersion is revealed, and an increase in the spectrum width with absorption anisotropy is found within some depth interval. It is shown that, at large depths, the direction of the displacement of the spectrum centroid, does not always coincide with the direction of minimum absorption
Magnetic dipole moments of deformed odd-odd nuclei up to 2p-1f shells
International Nuclear Information System (INIS)
Garg, V.P.; Verma, A.K.; Gandhi, R.; Sharma, S.D.
1981-01-01
The expression for magnetic moments for the states comprising ground state configurations of odd-odd nuclei has been simplified by excluding mixing of other nucleonic configurations. This is contrary to Sharma's and Davidson's results which had been obtained by diagonalizing state matrices for a set of parameters using Davidov and Filippov's non-axial rotor model. According to the relative directions of spins of unpaired odd nucleons, the nuclei have been classified under four categories-an exercise not attempted till now. The calculations have been done with various quenching factors depending upon the relative spin orientations of odd nucleons. For most of the nuclei, the results show considerable improvement over those of Gallagher and Moszkowski and of Sharma. (author)
Four-flavour leading hadronic contribution to the muon anomalous magnetic moment
Energy Technology Data Exchange (ETDEWEB)
Burger, Florian; Hotzel, Grit [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Feng, Xu [KEK National High Energy Physics, Tsukuba (Japan); Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Cyprus Univ. Nicosia (Cyprus). Dept. of Physics; Petschlies, Marcus [The Cyprus Institute, Nicosia (Cyprus); Renner, Dru B. [Jefferson Lab, Newport News, VA (United States)
2013-11-15
We present a four-flavour lattice calculation of the leading-order hadronic vacuum polarisation contribution to the anomalous magnetic moment of the muon, a{sup hvp}{sub {mu}}, arising from quark-connected Feynman graphs. It is based on ensembles featuring N{sub f}=2+1+1 dynamical twisted mass fermions generated by the European Twisted Mass Collaboration (ETMC). Several light quark masses are used in order to yield a controlled extrapolation to the physical pion mass. We employ three lattice spacings to examine lattice artefacts and several different volumes to check for finite-size effects. Including the complete first two generations of quarks allows for a direct comparison with phenomenological determinations of a{sup hvp}{sub {mu}}. Our final result involving an estimate of the systematic uncertainty a{sup hvp}{sub {mu}}=6.74(21)(18) x 10{sup -8} shows a good overall agreement with these computations.
Localized Magnetic Moments with Tunable Spin Exchange in a Gas of Ultracold Fermions
Riegger, L.; Darkwah Oppong, N.; Höfer, M.; Fernandes, D. R.; Bloch, I.; Fölling, S.
2018-04-01
We report on the experimental realization of a state-dependent lattice for a two-orbital fermionic quantum gas with strong interorbital spin exchange. In our state-dependent lattice, the ground and metastable excited electronic states of 173Yb take the roles of itinerant and localized magnetic moments, respectively. Repulsive on-site interactions in conjunction with the tunnel mobility lead to spin exchange between mobile and localized particles, modeling the coupling term in the well-known Kondo Hamiltonian. In addition, we find that this exchange process can be tuned resonantly by varying the on-site confinement. We attribute this to a resonant coupling to center-of-mass excited bound states of one interorbital scattering channel.
Magnetic moment of $^{17}$Ne using beta -NMR and tilted foil polarization
Baby, L T; Hass, M; Haas, H; Weissman, L; Brown, B A
2004-01-01
We report on the measurement of the magnetic moment of the ground state of /sup 17/Ne. Radioactive /sup 17/Ne nuclei were delivered from the high resolution mass separator at ISOLDE onto a high voltage platform at -200 kV and were polarized using the tilted foil polarization method. The polarized nuclei were implanted into a Pt stopper situated in a liquid-helium cooled beta -NMR apparatus and the asymmetry destruction of the ensuing beta rays was monitored as a function of the rf frequency applied to the polarized nuclei. The measured value of mu = 0.74 +or- 0.03 affirms the nu p/sub 1/2//sup - / nature of the ground state of /sup 17/Ne and is compared to shell model calculations. (10 refs).
Charged-Lepton-Flavour Violation in the CMSSM in View of the Muon Anomalous Magnetic Moment
Carvalho, D F; Gómez, M E; Lola, S; Ellis, John
2001-01-01
We use the BNL E821 measurement of g - 2, the anomalous magnetic moment of the muon, to normalize, within a supersymmetric GUT framework, constrained MSSM (CMSSM) predictions for processes that violate charged-lepton flavour conservation, including mu to e gamma, mu to e conversion and K^0_L to mu e. We illustrate our analysis with two examples of lepton mass matrix textures motivated by data on neutrino oscillations. We find that mu to e gamma may well occur at a rate within one or two (two or three) orders of magnitude of the present experimental upper limit if g - 2 is within the one- (two-)standard deviation range indicated by E821. We also find that mu to e conversion is likely to occur at rate measurable by MECO, and there is a chance that K^0_L to mu e may be observable in an experiment using an intense proton source.
Revised and improved value of the QED tenth-order electron anomalous magnetic moment
Aoyama, Tatsumi; Kinoshita, Toichiro; Nio, Makiko
2018-02-01
In order to improve the theoretical prediction of the electron anomalous magnetic moment ae we have carried out a new numerical evaluation of the 389 integrals of Set V, which represent 6,354 Feynman vertex diagrams without lepton loops. During this work, we found that one of the integrals, called X 024 , was given a wrong value in the previous calculation due to an incorrect assignment of integration variables. The correction of this error causes a shift of -1.26 to the Set V contribution, and hence to the tenth-order universal (i.e., mass-independent) term A1(10 ). The previous evaluation of all other 388 integrals is free from errors and consistent with the new evaluation. Combining the new and the old (excluding X 024 ) calculations statistically, we obtain 7.606 (192 )(α /π )5 as the best estimate of the Set V contribution. Including the contribution of the diagrams with fermion loops, the improved tenth-order universal term becomes A1(10 )=6.675 (192 ) . Adding hadronic and electroweak contributions leads to the theoretical prediction ae(theory)=1 159 652 182.032 (720 )×10-12 . From this and the best measurement of ae, we obtain the inverse fine-structure constant α-1(ae)=137.035 999 1491 (331 ) . The theoretical prediction of the muon anomalous magnetic moment is also affected by the update of QED contribution and the new value of α , but the shift is much smaller than the theoretical uncertainty.
Kuiper, Pieter; Searle, Barry G.; Rudolf, Petra; Tjeng, L.H.; Chen, C.T.
1993-01-01
We report strong magnetic linear dichroism at the Fe L2,3 edge of the antiferromagnet Fe2O3 (hematite). The relative difference in absorption for light polarized parallel and perpendicular to the magnetic moment is as high as 40% at the Fe L2 edge. The spectra are in excellent agreement with
International Nuclear Information System (INIS)
Solovyev, I.V.; Liechtenstein, A.I.; Gubanov, V.A.; Antropov, V.P.; Andersen, O.K.
1991-01-01
The linear-muffin-tin-orbital method is generalized to the case of relativistic and spin-polarized self-consistent band calculations. Our formalism is analogous to the standard orthogonal--linear-muffin-tin-orbital formalism, except that the potential functions and the potential parameters are now matrices. The method is used to perform density-functional calculations for fcc plutonium with different atomic volumes. The formation of spin and orbital magnetic moments, as well as the changes in the energy bands for volume changes corresponding to the α-δ transition, are investigated. The calculated magnetic moments agree quite well with the experimental ones
International Nuclear Information System (INIS)
Pasquevich, G.A.; Mendoza Zelis, P.; Sanchez, F.H.; Fernandez van Raap, M.B.; Veiga, A.L.; Martinez, N.
2006-01-01
We have applied the transmission Moessbauer effect at a constant Doppler velocity technique, under 75 Oe external oscillating magnetic field in the frequency range 0-200 Hz, to determine the dynamics of the iron magnetic moments in nanocrystalline ribbons Fe 90 Zr 7 B 3 . The experiment was performed at a fixed Doppler velocity coincident with an absorption line of the absorbent. Since the dependence of the absorption on the angle between the gamma ray directions and the magnetic field at the nuclear probe is known, the change in the orientation of the iron atomic magnetic moments with the external field can be inferred. Due to the fact that in this case the absorption lines from the nanocrystalline phase are resolved from the amorphous one, performing the experiment at distinct absorption lines, we were able to determine the dynamics of the atomic moments of each phase independently. These results are complemented with Moessbauer Spectroscopy
Dual-channel spontaneous emission of quantum dots in magnetic metamaterials.
Decker, Manuel; Staude, Isabelle; Shishkin, Ivan I; Samusev, Kirill B; Parkinson, Patrick; Sreenivasan, Varun K A; Minovich, Alexander; Miroshnichenko, Andrey E; Zvyagin, Andrei; Jagadish, Chennupati; Neshev, Dragomir N; Kivshar, Yuri S
2013-01-01
Metamaterials, artificial electromagnetic media realized by subwavelength nano-structuring, have become a paradigm for engineering electromagnetic space, allowing for independent control of both electric and magnetic responses of the material. Whereas most metamaterials studied so far are limited to passive structures, the need for active metamaterials is rapidly growing. However, the fundamental question on how the energy of emitters is distributed between both (electric and magnetic) interaction channels of the metamaterial still remains open. Here we study simultaneous spontaneous emission of quantum dots into both of these channels and define the control parameters for tailoring the quantum-dot coupling to metamaterials. By superimposing two orthogonal modes of equal strength at the wavelength of quantum-dot photoluminescence, we demonstrate a sharp difference in their interaction with the magnetic and electric metamaterial modes. Our observations reveal the importance of mode engineering for spontaneous emission control in metamaterials, paving a way towards loss-compensated metamaterials and metamaterial nanolasers.
Observation of magnetic flux generated spontaneously during a rapid quench of superconducting films
International Nuclear Information System (INIS)
Maniv, A.; Polturak, E.; Koren, G.
2003-01-01
We report observations of spontaneous formation of magnetic flux lines during a rapid quench of YBa 2 Cu 3 O 7-δ films through T c . This effect is predicted according to the Kibble-Zurek mechanism of creation of topological defects of the order parameter during a symmetry-breaking phase transition. Our previous experiment, at a quench rate of 20 K/s, gave null results. In the present experiment, the quench rate was increased to >10 8 K/s. The amount of spontaneous flux increases weakly with the cooling rate
DEFF Research Database (Denmark)
Monaco, Roberto; Aarøe, Morten; Mygind, Jesper
2008-01-01
We report on the spontaneous production of fluxons in annular Josephson tunnel junctions during a thermal quench in the presence of a symmetry-breaking magnetic field. The dependence on field intensity B of the probability (f) over bar (1) to trap a single defect during the N-S phase transition...... depends drastically on the sample circumferences. We show that this can be understood in the framework of the same picture of spontaneous defect formation that leads to the experimentally well attested scaling behavior of (f) over bar (1) with quench rate in the absence of an external field....
International Nuclear Information System (INIS)
Cameron, P.R.; Luccio, A.U.; Shea, T.J.; Tsoupas, N.; Goldberg, D.A.
1997-01-01
Effective polarimetry at high energies in hadron and lepton synchrotrons has been a long-standing and difficult problem. In synchrotrons with polarized beams it is possible to cause the direction of the polarization vector of a given bunch to alternate at a frequency which is some subharmonic of the rotation frequency. This can result in the presence of lines in the beam spectrum which are due only to the magnetic moment of the beam and which are well removed from the various lines due to the charge of the beam. The magnitude of these lines can be calculated from first principles. They are many orders of magnitude weaker than the Schottky signals. Measurement of the magnitude of one of these lines would be an absolute measurement of beam polarization. For measuring magnetic field, the Superconducting Quantum Interference Device, or squid, is about five orders of magnitude more sensitive than any other transducer. Using a squid, such a measurement might be accomplished with the proper combination of shielding, pickup loop design, and filtering. The resulting instrument would be fast, non-destructive, and comparatively cheap. In addition, techniques developed in the creation of such an instrument could be used to measure the Schottky spectrum in unprecedented detail. We present specifics of a polarimeter design for the Relativistic Heavy Ion Collider (RHIC) and briefly discuss the possibility of using this technique to measure polarization at high-energy electron machines like LEP and HERA. copyright 1997 American Institute of Physics
Kulkarni, Anita; Filippone, Bradley; Slutsky, Simon; Swank, Christopher; Carr, Robert; Osthelder, Charles; Biswas, Aritra; Molina, Daniel
2016-09-01
Over the last several decades, physicists have been measuring the neutron electric dipole moment (nEDM) with greater and greater sensitivity. The latest experiment we are developing will have 100 times more sensitivity than the previous leading experiment. A nonzero nEDM could, among other consequences, explain the presence of more matter than antimatter in the universe. To measure the nEDM with high accuracy, it is necessary to have a very uniform magnetic field inside the detector since non-uniformities can create false signals via the geometric phase effect. One way to improve field uniformity is to add superconducting lead endcaps to the detector, which constrain the fields at their surfaces to be parallel to them. Here, we test how the endcaps improve field uniformity by measuring the magnetic field at various points in a 1/3-scale experimental volume, inferring what the field must be at all other points, and calculating gradients in the field. This knowledge could help guide further steps needed to improve field uniformity and characterize limitations to the sensitivity of nEDM measurements for the full-scale experiment. Rose Hills Foundation, National Science Foundation Grant 1506459, and Department of Energy.
Magnetic moment and magnetocrystalline anisotropy of 3d-ion subsystem in R2T14B
International Nuclear Information System (INIS)
Bartashevich, M.I.; Kudrevatykh, N.V.; Andreev, A.V.; Rejmer, V.A.
1990-01-01
The effect of substituting cobalt for iron on the magnetic moment, magneto-crystalline anisotropy and thermal expansion of R 2 (Fe 1-x Co x ) 14 B single crystals (R=Y, Gd, 0≤x≤0.3) is investigated. The uniaxial magnetic anisotropy constant K 1 for the 3d-subsystem passes through a maximum at T=4.2 K with increasing Co concentration. For T c the temperature dependence of K 1 does not possess a positive slope. The magnetic moment of the 3d-subsystem at 4.2 K does not exhibit the maximum at intermediate concentrations observed for most R(Fe, Co)-intermetallics. An explanation is presented of the changes in the magnetic properties. It is shown that the variation of the interatomic distances on thermal expansion should not affect the magnitude of the anisotropy constant of the 3d- and R-subsystems
Proximity effects on the local magnetic moments of clusters V6-V9 embedded in a Fe matrix
International Nuclear Information System (INIS)
Sosa-Hernandez, E.M.; Alvarado-Leyva, P.G.
2006-01-01
The magnetic behavior of clusters V 6 -V 9 in bulk Fe is determined by using an electronic Hamiltonian which includes s, p and d electrons. The spin density distribution is calculated self-consistenly in the unrestricted Hartree-Fock approximation. The local magnetic moments are obtained at V and Fe atoms; the magnetic coupling between Fe and V atoms is antiferromagnetic-like. We consider two cases, the first case correspond to non-interacting clusters, the distance between them is infinity, and the another case, when the clusters are interacting, the separation between them is finite; in the first case, the magnetic order in V 6 is ferromagnetic-like whereas for V 9 the magnetic order is antiferromagnetic-like, in the second case we have found that the magnetic order is not well stablished in V 6 . We have found that the magnetic order in the matrix is not broken by the presence of the V atoms, although the local magnetic moments of Fe atoms at the interface cluster-matrix, are reduced respect to Fe bulk magnetization (2.22μ B ) [e.g. μ Fe (5) = 1.98μ B in V 6 ; μ Fe (3) 1.89μ B in V 9
Bakker, B.L.G.; Ji, C.R.
2005-01-01
In the calculation of the anomalous magnetic moment of W± bosons, we discuss vector anomalies occurring in the fermion loop that spoil the predictive power of the theory. While the previous analyses were limited to using essentially the manifestly covariant dimensional regulation method, we extend
Masjuan, Pere; Vanderhaeghen, Marc
2014-01-01
We present the mini-proceedings of the workshops Hadronic contributions to the muon anomalous magnetic moment: strategies for improvements of the accuracy of the theoretical prediction and $(g-2)_{\\mu}$: Quo vadis?, both held in Mainz from April 1$^{\\rm rst}$ to 5$^{\\rm th}$ and from April 7$^{\\rm th}$ to 10$^{\\rm th}$, 2014, respectively.
Energy Technology Data Exchange (ETDEWEB)
Meyer, Harvey B. [Mainz Univ., PRISMA Cluster of Excellence, Inst. fuer Kernphysik und Helmholtz Institut Mainz (Germany)
2017-09-15
We present a Lorentz-covariant, Euclidean coordinate-space expression for the hadronic vacuum polarisation, the Adler function and the leading hadronic contribution to the anomalous magnetic moment of the muon. The representation offers a high degree of flexibility for an implementation in lattice QCD. We expect it to be particularly helpful for the quark-line disconnected contributions. (orig.)
Rock-magnetic properties of TRM carrying baked and molten rocks straddling burnt coal seams
Boer, C.B. de; Dekkers, M.J.; Hoof, Ton A.M. van
2001-01-01
The subsurface spontaneous combustion of coal seams in Xinjiang (NW China) during Pleistocene to recent times produced large areas of thermally altered sedimentary rocks with large magnetic moments. The natural remanent magnetization (NRM) and thermoremanent magnetization (TRM) intensities and
International Nuclear Information System (INIS)
Scheunert, G; Ward, C; Hendren, W R; Bowman, R M; Lapicki, A A; Hardeman, R; Mooney, M; Gubbins, M
2014-01-01
Despite being the most suitable candidates for solenoid pole pieces in state-of-the-art superconductor-based electromagnets, the intrinsic magnetic properties of heavy rare earth metals and their alloys have gained comparatively little attention. With the potential of integration in micro and nanoscale devices, thin films of Gd, Dy, Tb, DyGd and DyTb were plasma-sputtered and investigated for their in-plane magnetic properties, with an emphasis on magnetization versus temperature profiles. Based on crystal structure analysis of the polycrystalline rare earth films, which consist of a low magnetic moment fcc layer at the seed interface topped with a higher moment hcp layer, an experimental protocol is introduced which allows the direct magnetic analysis of the individual layers. In line with the general trend of heavy lanthanides, the saturation magnetization was found to drop with increasing unit cell size. In situ annealed rare earth films exceeded the saturation magnetization of a high-moment Fe 65 Co 35 reference film in the cryogenic temperature regime, proving their potential for pole piece applications; however as-deposited rare earth films were found completely unsuitable. In agreement with theoretical predictions, sufficiently strained crystal phases of Tb and Dy did not exhibit an incommensurate magnetic order, unlike their single-crystal counterparts which have a helical phase. DyGd and DyTb alloys followed the trends of the elemental rare earth metals in terms of crystal structure and magnetic properties. Inter-rare-earth alloys hence present a desirable blend of saturation magnetization and operating temperature. (paper)
Hou, Y. S.; Xiang, H. J.; Gong, X. G.
2017-08-01
Recent experiments reveal that the honeycomb ruthenium trichloride α -RuC l3 is a prime candidate of the Kitaev quantum spin liquid (QSL). However, there is no theoretical model which can properly describe its experimental dynamical response due to the lack of a full understanding of its magnetic interactions. Here, we propose a general scheme to calculate the magnetic interactions in systems (e.g., α -RuC l3 ) with nonnegligible orbital moments by constraining the directions of orbital moments. With this scheme, we put forward a minimal J1-K1-Γ1-J3-K3 model for α -RuC l3 and find that: (I) The third nearest neighbor (NN) antiferromagnetic Heisenberg interaction J3 stabilizes the zigzag antiferromagnetic order; (II) The NN symmetric off-diagonal exchange Γ1 plays a pivotal role in determining the preferred direction of magnetic moments and generating the spin wave gap. An exact diagonalization study on this model shows that the Kitaev QSL can be realized by suppressing the NN symmetric off-diagonal exchange Γ1 and the third NN Heisenberg interaction J3. Thus, we not only propose a powerful general scheme for investigating the intriguing magnetism of Jeff=1 /2 magnets, but also point out future directions for realizing the Kitaev QSL in the honeycomb ruthenium trichloride α -RuC l3 .
International Nuclear Information System (INIS)
Kondratyuk, L.A.; Krivoruchenko, M.I.; Shchepkin, M.G.
1986-01-01
The magnetic moment of the six-quark bag with the deuteron quantum numbers is calculated in the chiral bag model taking into account the gluonic and the pionic corrections. For the six-quark bag radius R 6q =1.18-1.38 fm (corresponding to the nucleon bag radius R 3q =0.8-1.0 fm) the magnetic moment equals m D 6q =1.17-1.23 nuclear magnetons. This result together with the deuteron magnetic momentum data provides a restraint upon the six-quark bag admixture in the deuteron P B < or approx. 3%. This value is a few times lower than the probability that two nucleons are in the range r < 1.4 fm. Therefore, it may be interpreted as an evidence for a considerable difference between the properties of the effective bag in the deuteron and of the MIT bag
Postma, H; Heyde, K; Walker, P; Grant, I; Veskovic, M; Stone, N; Stone, J
2002-01-01
% IS301 \\\\ \\\\ Low temperature nuclear orientation of isotope-separator implanted short-lived radio-isotopes makes possible the measurements of nuclear magnetic dipole moments of oriented ground and excited states with half-lives longer than a few seconds. Coupling schemes characterizing the odd nucleons and ground-state deformations can be extracted from the nuclear moments. \\\\ We thus propose to measure the magnetic dipole moments of $^{127-133}$Sb to high precision using NMR/ON at the NICOLE facility. With (double magic +1) $^{133}$Sb as the reference, the main aim of this experiment is to examine whether the collective component in the 7/2$^+$ Sb ground state magnetic dipole moment varies as expected according to particle-core coupling calculations carried out for the Sb (Z=51) isotopes. Comparison of the 1-proton-particle excitations in Sb to 1-proton-hole states in In nuclei will shed light on differences between particle and hole excitations as understood within the present model. Comparison of ...
Directory of Open Access Journals (Sweden)
Andrey V. Chubukov
2016-12-01
Full Text Available Magnetism and nematic order are the two nonsuperconducting orders observed in iron-based superconductors. To elucidate the interplay between them and ultimately unveil the pairing mechanism, several models have been investigated. In models with quenched orbital degrees of freedom, magnetic fluctuations promote stripe magnetism, which induces orbital order. In models with quenched spin degrees of freedom, charge fluctuations promote spontaneous orbital order, which induces stripe magnetism. Here, we develop an unbiased approach, in which we treat magnetic and orbital fluctuations on equal footing. Key to our approach is the inclusion of the orbital character of the low-energy electronic states into renormalization group (RG analysis. We analyze the RG flow of the couplings and argue that the same magnetic fluctuations, which are known to promote s^{+-} superconductivity, also promote an attraction in the orbital channel, even if the bare orbital interaction is repulsive. We next analyze the RG flow of the susceptibilities and show that, if all Fermi pockets are small, the system first develops a spontaneous orbital order, then s^{+-} superconductivity, and magnetic order does not develop down to T=0. We argue that this scenario applies to FeSe. In systems with larger pockets, such as BaFe_{2}As_{2} and LaFeAsO, we find that the leading instability is either towards a spin-density wave or superconductivity. We argue that in this situation nematic order is caused by composite spin fluctuations and is vestigial to stripe magnetism. Our results provide a unifying description of different iron-based materials.
International Nuclear Information System (INIS)
Heinzel, C.; Theilig, T.; Ziemann, P.
1993-01-01
It has been reported recently by Braunisch et al. [Phys. Rev. Lett. 68, 1908 (1992)] that some ceramic high-T c superconductors (HTSC's) exhibit a paramagnetic signal if cooled through the superconducting transition temperature in small external magnetic dc fields (H dc 2 Sr 2 CaCu 2 O 8-x samples, some of which did not exhibit the PME. Thus, a comparison was possible between samples with and without the PME, subjected to different field-cooling procedures. The experimental results are consistent with the occurrence of a reversible transition into a PME state carrying spontaneous orbital currents resulting in corresponding paramagnetic moments, which can be reversibly aligned by small external dc fields. This PME state is attributed to loops containing relatively strong weak links, which are able to remain superconducting close to the bulk T c of the grains (e.g., at T/T c =0.9) and in external dc fields of at least 30 Oe
Landler, Lukas; Painter, Michael S; Youmans, Paul W; Hopkins, William A; Phillips, John B
2015-01-01
We investigated spontaneous magnetic alignment (SMA) by juvenile snapping turtles using exposure to low-level radio frequency (RF) fields at the Larmor frequency to help characterize the underlying sensory mechanism. Turtles, first introduced to the testing environment without the presence of RF aligned consistently towards magnetic north when subsequent magnetic testing conditions were also free of RF ('RF off → RF off'), but were disoriented when subsequently exposed to RF ('RF off → RF on'). In contrast, animals initially introduced to the testing environment with RF present were disoriented when tested without RF ('RF on → RF off'), but aligned towards magnetic south when tested with RF ('RF on → RF on'). Sensitivity of the SMA response of yearling turtles to RF is consistent with the involvement of a radical pair mechanism. Furthermore, the effect of RF appears to result from a change in the pattern of magnetic input, rather than elimination of magnetic input altogether, as proposed to explain similar effects in other systems/organisms. The findings show that turtles first exposed to a novel environment form a lasting association between the pattern of magnetic input and their surroundings. However, under natural conditions turtles would never experience a change in the pattern of magnetic input. Therefore, if turtles form a similar association of magnetic cues with the surroundings each time they encounter unfamiliar habitat, as seems likely, the same pattern of magnetic input would be associated with multiple sites/localities. This would be expected from a sensory input that functions as a global reference frame, helping to place multiple locales (i.e., multiple local landmark arrays) into register to form a global map of familiar space.
Energy Technology Data Exchange (ETDEWEB)
Brodsky, Stanley J.; /SLAC; Gardner, Susan; /Kentucky U.; Hwang, Dae Sung; /Sejong U.
2006-01-11
We consider the electric dipole form factor, F{sub 3}(q{sup 2}), as well as the Dirac and Pauli form factors, F{sub 1}(q{sup 2}) and F{sub 2}(q{sup 2}), of the nucleon in the light-front formalism. We derive an exact formula for F{sub 3}(q{sup 2}) to complement those known for F{sub 1}(q{sup 2}) and F{sub 2}(q{sup 2}). We derive the light-front representation of the discrete symmetry transformations and show that time-reversal- and parity-odd effects are captured by phases in the light-front wave functions. We thus determine that the contributions to F{sub 2}(q{sup 2}) and F{sub 3}(q{sup 2}), Fock-state by Fock-state, are related, independent of the fundamental mechanism through which CP violation is generated. Our relation is not specific to the nucleon, but, rather, is true of spin-1/2 systems in general, be they lepton or baryon. The empirical values of the anomalous magnetic moments, in concert with empirical bounds on the associated electric dipole moments, can better constrain theories of CP violation. In particular, we find that the neutron and proton electric dipole moments echo the isospin structure of the anomalous magnetic moments, {kappa}{sup n} {approx} -{kappa}{sup p}.
A call for new physics: The muon anomalous magnetic moment and lepton flavor violation
Lindner, Manfred; Platscher, Moritz; Queiroz, Farinaldo S.
2018-02-01
We review how the muon anomalous magnetic moment (g - 2) and the quest for lepton flavor violation are intimately correlated. Indeed the decay μ → eγ is induced by the same amplitude for different choices of in- and outgoing leptons. In this work, we try to address some intriguing questions such as: Which hierarchy in the charged lepton sector one should have in order to reconcile possible signals coming simultaneously from g - 2and lepton flavor violation? What can we learn if the g - 2anomaly is confirmed by the upcoming flagship experiments at FERMILAB and J-PARC, and no signal is seen in the decay μ → eγin the foreseeable future? On the other hand, if the μ → eγdecay is seen in the upcoming years, do we need to necessarily observe a signal also in g - 2?. In this attempt, we generally study the correlation between these observables in a detailed analysis of simplified models. We derive master integrals and fully analytical and exact expressions for both phenomena, and address other flavor violating signals. We investigate under which conditions the observations can be made compatible and discuss their implications. Lastly, we discuss in this context several extensions of the SM, such as the Minimal Supersymmetric Standard Model, Left-Right symmetric model, B- L model, scotogenic model, two Higgs doublet model, Zee-Babu model, 331 model, and Lμ -Lτ, dark photon, seesaw models type I, II and III, and also address the interplay with μ → eee decay and μ- e conversion.
Spontaneous electric polarization in the B-site magnetic spinel GeCu2O4
Yanda, Premakumar; Ghara, Somnath; Sundaresan, A.
2018-04-01
We report the observation of a spontaneous electric polarization at the antiferromagnetic ordering temperature (TN ∼ 33 K) of Cu2+ ions in the B-site magnetic spinel GeCu2O4, synthesized at high pressure and high temperature. This compound is known to crystallize in a tetragonal structure (space group I41/amd) due to Jahn-Teller distortion of Cu2+ ions and exhibit a collinear up-up-down-down (↑↑↓↓) antiferromagnetic spin configuration below TN. We found a clear dielectric anomaly at TN, where an electric polarization appears in the absence of applied magnetic field. The electric polarization is suppressed by applied magnetic fields, which demonstrates that the compound GeCu2O4 is a type-II multiferroic.
International Nuclear Information System (INIS)
Cabral-Rosetti, L.G.; Bernabeu, J.; Vidal, J.
2000-01-01
We present a computation of the charge and the magnetic moment of the neutrino in the recently developed electro-weak background field method and in the linear R ξ L gauge. First, we deduce a formal Ward-Takahashi identity which implies the immediate cancellation of the neutrino electric charge. This Ward-Takahashi identity is as simple as that for QED. The computation of the (proper and improper) one loop vertex diagrams contributing to the neutrino electric charge is also presented in an arbitrary gauge, checking in this way the Ward-Takahashi identity previously obtained. Finally, the calculation of the magnetic moment of the neutrino, in the minimal extension of the standard model with massive Dirac neutrinos, is presented, showing its gauge parameter and gauge structure independence explicitly. (orig.)
Double-trap measurement of the proton magnetic moment at 0.3 parts per billion precision.
Schneider, Georg; Mooser, Andreas; Bohman, Matthew; Schön, Natalie; Harrington, James; Higuchi, Takashi; Nagahama, Hiroki; Sellner, Stefan; Smorra, Christian; Blaum, Klaus; Matsuda, Yasuyuki; Quint, Wolfgang; Walz, Jochen; Ulmer, Stefan
2017-11-24
Precise knowledge of the fundamental properties of the proton is essential for our understanding of atomic structure as well as for precise tests of fundamental symmetries. We report on a direct high-precision measurement of the magnetic moment μ p of the proton in units of the nuclear magneton μ N The result, μ p = 2.79284734462 (±0.00000000082) μ N , has a fractional precision of 0.3 parts per billion, improves the previous best measurement by a factor of 11, and is consistent with the currently accepted value. This was achieved with the use of an optimized double-Penning trap technique. Provided a similar measurement of the antiproton magnetic moment can be performed, this result will enable a test of the fundamental symmetry between matter and antimatter in the baryonic sector at the 10 -10 level. Copyright © 2017, American Association for the Advancement of Science.
Singular twisting moment in a cracked thin plate under an electric current flow and a magnetic field
International Nuclear Information System (INIS)
Shindo, Yasuhide; Tamura, Hitoshi
1988-01-01
This paper deals with the electromagneto-elastic problem of an elastic conducting thin plate containing a through crack under a uniform electric current flow and a constant magnetic field. The current flow is disturbed by the presence of the crack and a twisting moment is caused by the interaction between the magnetic field and the disturbed current. Two problems concerning the electric current density field and the electromagneto-elastic field are formulated by means of integral transform techniques and reduced to two pairs of dual integral equations. These integral equations are solved exactly, and the singular current densities, the displacement of the crack surface and the singular moments near the crack tip are expressed in closed forms. (author)
Energy Technology Data Exchange (ETDEWEB)
Feng, Xu [DESY, Zeuthen (Germany). NIC; Muenster Univ. (Germany). Inst. fuer Theoretische Physik; Jansen, Karl; Renner, Dru B. [DESY, Zeuthen (Germany). NIC; Petschlies, Marcus [Humboldt Univ. Berlin (Germany). Inst. fuer Physik
2011-03-15
We present a reliable nonperturbative calculation of the QCD correction, at leading-order in the electromagnetic coupling, to the anomalous magnetic moment of the electron, muon and tau leptons using two-flavor lattice QCD. We use multiple lattice spacings, multiple volumes and a broad range of quark masses to control the continuum, in nite-volume and chiral limits. We examine the impact of the commonly ignored disconnected diagrams and introduce a modi cation to the previously used method that results in a well-controlled lattice calculation. We obtain 1.513(43).10{sup -12}, 5.72(16).10{sup -8} and 2.650(54).10{sup -6} for the leading-order QCD correction to the anomalous magnetic moment of the electron, muon and tau respectively, each accurate to better than 3%. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Silenko, Alexander J. [Belarusian State University, Research Institute for Nuclear Problems, Minsk (Belarus); Joint Institute for Nuclear Research, Bogoliubov Laboratory of Theoretical Physics, Dubna (Russian Federation)
2017-05-15
A general theoretical description of a magnetic resonance is presented. This description is necessary for a detailed analysis of spin dynamics in electric-dipole-moment experiments in storage rings. General formulas describing a behavior of all components of the polarization vector at the magnetic resonance are obtained for an arbitrary initial polarization. These formulas are exact on condition that the nonresonance rotating field is neglected. The spin dynamics is also calculated at frequencies far from resonance with allowance for both rotating fields. A general quantum-mechanical analysis of the spin evolution at the magnetic resonance is fulfilled and the full agreement between the classical and quantum-mechanical approaches is shown. Quasimagnetic resonances for particles and nuclei moving in noncontinuous perturbing fields of accelerators and storage rings are considered. Distinguishing features of quasimagnetic resonances in storage ring electric-dipole-moment experiments are investigated in detail. The exact formulas for the effect caused by the electric dipole moment are derived. The difference between the resonance effects conditioned by the rf electric-field flipper and the rf Wien filter is found and is calculated for the first time. The existence of this difference is crucial for the establishment of a consent between analytical derivations and computer simulations and for checking spin tracking programs. The main systematical errors are considered. (orig.)
International Nuclear Information System (INIS)
Casperson, D.E.; Crane, T.W.; Denison, A.B.; Egan, P.O.; Hughes, V.W.; Mariam, F.G.; Orth, H.; Reist, H.W.; Souder, P.A.; Stambaugh, R.D.; Thompson, P.A.; zu Putlitz, G.
1977-01-01
Measurements of Zeeman transitions in the ground state of muonium at strong magnetic field have yielded values for the hfs interval, Δν = 4463 302.35(52) kHz (0.12 ppm) and for the muon magnetic moment, μ/sub μ//μ/sub p/ = 3.183 3403(44) (1.4 ppm), fo considerably higher precision than previous results. The theoretical expression for Δν, including our measured value of μ/sub μ//μ/sub p/, disagrees with the experimental value by 2.5 standard deviations. The electronic g/sub J/ density shift for muonium in Kr has been measured
Shao, Yangfan; Pang, Rui; Pan, Hui; Shi, Xingqiang
2018-03-01
The interfaces between organic molecules and magnetic metals have gained increasing interest for both fundamental reasons and applications. Among them, the C60/layered antiferromagnetic (AFM) interfaces have been studied only for C60 bonded to the outermost ferromagnetic layer [S. L. Kawahara et al., Nano Lett. 12, 4558 (2012) and D. Li et al., Phys. Rev. B 93, 085425 (2016)]. Here, via density functional theory calculations combined with evidence from the literature, we demonstrate that C60 adsorption can reconstruct the layered-AFM Cr(001) surface at elevated annealing temperatures so that C60 bonds to both the outermost and the subsurface Cr layers in opposite spin directions. Surface reconstruction drastically changes the adsorbed molecule spintronic properties: (1) the spin-split p-d hybridization involves multi-orbitals of C60 and top two layers of Cr with opposite spin-polarization, (2) the subsurface Cr atom dominates the C60 electronic properties, and (3) the reconstruction induces a large magnetic moment of 0.58 μB in C60 as a synergistic effect of the top two Cr layers. The induced magnetic moment in C60 can be explained by the magnetic direct-exchange mechanism, which can be generalized to other C60/magnetic metal systems. Understanding these complex hybridization behaviors is a crucial step for molecular spintronic applications.
Enhancement of the Magnetic Ordered Moment in Electron-doped BaFe2As2 under Uniaxial Pressure
Tam, David; Song, Yu; Dai, Pengcheng
Many iron superconductors exhibit structural and magnetic phases that break the in-plane symmetry of the iron-pnitogen or iron-chalcogen layers. We developed a new apparatus to apply large and highly controllable in-plane uniaxial stress to these materials along the direction of the orthorhombic distortion at low temperature. Using several complimentary techniques, including DC electrical resistivity, neutron diffraction, and muon spin relaxation, we find that crystalline twinning in BaFe2-xNixAs2 and Ba(Fe1-xCox)2As2 is completely suppressed and the magnetic ordering temperature increases under modest uniaxial pressure, consistent with the idea that orthorhombicity favors the magnetic phase. Moreover, we find an enhancement of the magnetic ordered moment in the samples near the superconducting regime. We argue these results demonstrate the importance of quantum fluctuations for superconductivity, for which uniaxial stress is a novel probe.
The origin for increase of magnetic moment of Co in Co-doped SnO{sub 2} with oxygen vacancies
Energy Technology Data Exchange (ETDEWEB)
Wang, Hongxia; Zong, Zhaocun; Li, Peng [College of Mathematics, Physics, and Information Science, Zhejiang Ocean University, Zhoushan (China); Yan, Yu [State Key Laboratory of Superhard Materials, Department of Physics, Jilin University, Changchun (China)
2011-12-15
In Co-doped SnO{sub 2} fivefold degenerate Co-3d states split into five singlet states. The magnetic moment of Co is mainly contributed by the spin polarization of Co-d{sub xy} states. The introduction of oxygen vacancies largely increases the magnetic moment of Co. The increase of Co magnetic moment is caused by the conversion of spin-spin coupling between Co and its neighboring O atoms from antiparallel to parallel, which attributes to the hybridization and electrons transfer between oxygen vacancy impurity states and Co-3d states. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Controlled and spontaneous magnetic field generation in a gun-driven spheromak
International Nuclear Information System (INIS)
Woodruff, S.; Cohen, B.I.; Hooper, E.B.; Mclean, H.S.; Stallard, B.W.; Hill, D.N.; Holcomb, C.T.; Romero-Talamas, C.; Wood, R.D.; Cone, G.; Sovinec, C.R.
2005-01-01
In the Sustained Spheromak Physics Experiment, SSPX [E. B. Hooper, D. Pearlstein, and D. D. Ryutov, Nucl. Fusion 39, 863 (1999)], progress has been made in understanding the mechanisms that generate fields by helicity injection. SSPX injects helicity (linked magnetic flux) from 1 m diameter magnetized coaxial electrodes into a flux-conserving confinement region. Control of magnetic fluctuations (δB/B∼1% on the midplane edge) yields T e profiles peaked at >200 eV. Trends indicate a limiting beta (β e ∼4%-6%), and so we have been motivated to increase T e by operating with stronger magnetic field. Two new operating modes are observed to increase the magnetic field: (A) Operation with constant current and spontaneous gun voltage fluctuations. In this case, the gun is operated continuously at the threshold for ejection of plasma from the gun: stored magnetic energy of the spheromak increases gradually with δB/B∼2% and large voltage fluctuations (δV∼1 kV), giving a 50% increase in current amplification, I tor /I gun . (B) Operation with controlled current pulses. In this case, spheromak magnetic energy increases in a stepwise fashion by pulsing the gun, giving the highest magnetic fields observed for SSPX (∼0.7 T along the geometric axis). By increasing the time between pulses, a quasisteady sustainment is produced (with periodic good confinement), comparing well with resistive magnetohydrodynamic simulations. In each case, the processes that transport the helicity into the spheromak are inductive and exhibit a scaling of field with current that exceeds those previously obtained. We use our newly found scaling to suggest how to achieve higher temperatures with a series of pulses
Controlled and Spontaneous Magnetic Field Generation in a Gun-Driven Spheromak
International Nuclear Information System (INIS)
Woodruff, S; Cohen, B I; Hooper, E B; McLean, H S; Stallard, B W; Hill, D N; Holcomb, C T; Romero-Talamas, C; Wood, R D; Cone, G; Sovinec, C R
2005-04-01
In the Sustained Spheromak Physics Experiment, SSPX, progress has been made in understanding the mechanisms that generate fields by helicity injection. SSPX injects helicity (linked magnetic flux) from 1-m diameter magnetized coaxial electrodes into a flux-conserving confinement region. Control of magnetic fluctuations ((delta)B/B∼1% on the midplane edge) yields T e profiles peaked at > 200eV. Trends indicate a limiting beta (β e ∼ 4-6%), and so we have been motivated to increase T e by operating with stronger magnetic field. Two new operating modes are observed to increase the magnetic field: (A) Operation with constant current and spontaneous gun voltage fluctuations. In this case, the gun is operated continuously at the threshold for ejection of plasma from the gun: stored magnetic energy of the spheromak increases gradually with (delta)B/B ∼2% and large voltage fluctuations ((delta)V ∼ 1kV), giving a 50% increase in current amplification, I tor /I gun . (B) Operation with controlled current pulses. In this case, spheromak magnetic energy increases in a stepwise fashion by pulsing the gun, giving the highest magnetic fields observed for SSPX (∼0.7T along the geometric axis). By increasing the time between pulses, a quasi-steady sustainment is produced (with periodic good confinement), comparing well with resistive MHD simulations. In each case, the processes that transport the helicity into the spheromak are inductive and exhibit a scaling of field with current that exceeds those previously obtained. We use our newly found scaling to suggest how to achieve higher temperatures with a series of pulses
Golovko, V.V.; Phalet, T.; Delaure, B.; Beck, M.; Kozlov, V.Yu.; Coeck, S.; Wauters, F.; Herzog, P.; Tramm, Ch.; Zakoucky, D.; Venos, D.; Srnka, D.; Honusek, M.; Koster, U.; Severijns, N.
2010-01-01
Nuclear magnetic resonance (NMR/ON) measurements with beta- and gamma-ray detection have been performed on oriented Ag-104(g,m) nuclei with the NICOLE He-3-He-4 dilution refrigerator setup at ISOLDE/CERN. For Ag-104(g) (I-pi = 5(+)) the gamma-NMR/ON resonance signal was found at nu = 266.70(5) MHz. Combining this result with the known magnetic moment for this isotope, the magnetic hyperfine field of Ag impurities in an Fe host at low temperature (< 1 K) is found to be vertical bar B-hf(AgFe)vertical bar = 44.709(35) T. A detailed analysis of other relevant data available in the literature yields three more values for this hyperfine field. Averaging all four values yields a new and precise value for the hyperfine field of Ag in Fe; that is, vertical bar B-hf(AgFe)vertical bar = 44.692(30) T. For Ag-104(m) (I-pi = 2(+)), the anisotropy of the beta particles provided the NMR/ON resonance signal at nu = 627.7(4) MHz. Using the new value for the hyperfine field of Ag in Fe, this frequency corresponds to the mag...
Magnetic resonance imaging features of spontaneously regressed thymoma: report of 2 cases.
Nakazono, Takahiko; Yamaguchi, Ken; Egashira, Ryoko; Satoh, Toshimi; Yamasaki, Fumio; Mitsuoka, Masahiro; Hayashi, Shinichiro; Kudo, Sho
2009-02-01
The authors describe 2 cases in which thymoma spontaneously regressed. The first patient was a 49-year-old woman with myasthenia gravis. A chest radiograph on admission showed an anterior mediastinal mass that spontaneously decreased in size as shown on a radiograph obtained 2 weeks later. Surgical removal of the mass was performed and the histopathologic examination showed a type B2 thymoma with marked coagulation necrosis in the central area. The second patient was a 46-year-old woman who was hospitalized due to chest and back pain. A chest radiograph on admission showed an anterior mediastinal mass and bilateral pleural effusion. The mass decreased in size and the effusion disappeared as shown on a chest radiograph obtained 2 months later. Computed tomography-guided biopsy was performed, and histopathologic examination revealed thymoma with marked necrosis. In both cases, dynamic contrast-enhanced magnetic resonance images showed peripheral ringlike enhancement of the mass. The clinical and radiologic features of spontaneously regressed thymoma may be different from those of common thymoma.
Energy Technology Data Exchange (ETDEWEB)
Silenko, Alexander J. [Belarusian State University, Research Institute for Nuclear Problems, Minsk (Belarus); Joint Institute for Nuclear Research, Bogoliubov Laboratory of Theoretical Physics, Dubna (Russian Federation)
2017-10-15
We calculate the corrections for constant radial magnetic field in muon g - 2 and electric-dipole-moment experiments in storage rings. While the correction is negligible for the current generation of g - 2 experiments, it affects the upcoming muon electric-dipole-moment experiment at Fermilab. (orig.)
International Nuclear Information System (INIS)
Orgassa, D.; Fujiwara, H.; Schulthess, T. C.; Butler, W. H.
2000-01-01
Using half-metallic ferromagnets in spin-dependent devices, like spin valves and ferromagnetic tunnel junctions, is expected to increase the device performance. However, using the half-metallic ferromagnet NiMnSb in such devices led to much less than ideal results. One of the possible sources for this behavior is atomic disorder. First-principles calculations of the influence of atomic disorder on the electronic structure of NiMnSb underline the sensitivity of half-metallic properties in NiMnSb to atomic disorder. In this article, we report on the disorder dependence of the total magnetic moment calculated by applying the layer Korringa-Kohn-Rostoker method in conjunction with the coherent potential approximation. We consider the following types of disorder: (1) intermixing of Ni and Mn, (2) partial occupancy of a normally vacant lattice site by Ni and Mn, and (3) partial occupancy of this site by Mn and Sb. In all cases the composition is kept stoichiometric. All three types of disorder decrease the moment monotonically with increasing disorder levels. For the experimentally seen disorder of 5% Mn and 5% Sb on the normally vacant lattice site, the total moment is decreased by 4.1%. The results suggest that precise measurement of the saturation magnetization of NiMnSb thin films can give information on the disorder. (c) 2000 American Institute of Physics
Stuart, Keith; Bartosh, Blake
1993-01-01
Innovative Information Systems (IIS), Inc. is in the process of designing and fabricating a high bandwidth force and moment measuring device (i.e. the Magnetic Thruster Test Stand). This device will use active magnetic suspension to allow direct measurements of the forces and torques generated by the rocket engines of the missile under test. The principle of operation of the Magnetic Thruster Test Stand (MTTS) is based on the ability to perform very precise, high bandwidth force and position measurements on an object suspended in a magnetic field. This ability exists due to the fact that the digital servo control mechanism that performs the magnetic suspension uses high bandwidth (10 kHz) position data (via an eddy-current proximity sensor) to determine the amount of force required to maintain stable suspension at a particular point. This force is converted into required electromagnet coil current, which is then output to a current amplifier driving the coils. A discussion of how the coil current and magnetic gap distance (the distance between the electromagnet and the object being suspended) is used to determine the forces being applied from the suspended assembly is presented.
Manz, Thomas A; Sholl, David S
2011-12-13
The partitioning of electron spin density among atoms in a material gives atomic spin moments (ASMs), which are important for understanding magnetic properties. We compare ASMs computed using different population analysis methods and introduce a method for computing density derived electrostatic and chemical (DDEC) ASMs. Bader and DDEC ASMs can be computed for periodic and nonperiodic materials with either collinear or noncollinear magnetism, while natural population analysis (NPA) ASMs can be computed for nonperiodic materials with collinear magnetism. Our results show Bader, DDEC, and (where applicable) NPA methods give similar ASMs, but different net atomic charges. Because they are optimized to reproduce both the magnetic field and the chemical states of atoms in a material, DDEC ASMs are especially suitable for constructing interaction potentials for atomistic simulations. We describe the computation of accurate ASMs for (a) a variety of systems using collinear and noncollinear spin DFT, (b) highly correlated materials (e.g., magnetite) using DFT+U, and (c) various spin states of ozone using coupled cluster expansions. The computed ASMs are in good agreement with available experimental results for a variety of periodic and nonperiodic materials. Examples considered include the antiferromagnetic metal organic framework Cu3(BTC)2, several ozone spin states, mono- and binuclear transition metal complexes, ferri- and ferro-magnetic solids (e.g., Fe3O4, Fe3Si), and simple molecular systems. We briefly discuss the theory of exchange-correlation functionals for studying noncollinear magnetism. A method for finding the ground state of systems with highly noncollinear magnetism is introduced. We use these methods to study the spin-orbit coupling potential energy surface of the single molecule magnet Fe4C40H52N4O12, which has highly noncollinear magnetism, and find that it contains unusual features that give a new interpretation to experimental data.
Calculation of the orbital magnetic moments in fcc 3d-4d binary clusters: Co-Rh and Co-Pd
International Nuclear Information System (INIS)
Munoz-Navia, M; Dorantes-Davila, J; Pastor, G M
2004-01-01
The orbital magnetic moments ( ) and spin moments ( ) of mixed fcc Co N Pd M and Co N Rh M (N,M = 19,24) clusters are determined by using a self-consistent real-space tight binding method. In all cases considered, amounts to 20%-50% of the total magnetic moment M z (M z =2 z > + z >). Moreover, the M z are remarkably larger than the M z (Co) values of the single Co cluster, due mainly to the local spin moments iz > induced at the Pd and Rh atoms, which amount to about 20% of M z (2 iz > Pd,Rh =0.1-0.8 μ B and to a considerable enhancement of the orbital moments Co > at the Co atoms ( Co >=0.2-1 μ B ). These results are analysed from a local perspective
International Nuclear Information System (INIS)
Lamoreaux, S.K.
1999-01-01
A simple formulation for calculating the magnetic field external to an extended nonpermeable conducting body due to thermal current fluctuations within the body is developed, and is applied to a recent experimental search for the atomic electric-dipole moment (EDM) of 199 Hg. It is shown that the thermal fluctuation field is only slightly smaller in magnitude than other noise sources in that experiment. The formulation is extended to permeable bodies, and the implications for general EDM experiments are discussed. copyright 1999 The American Physical Society
Effects of a non-standard W± magnetic moment in W± production via deep inelastic e-P scattering
International Nuclear Information System (INIS)
Boehm, M.; Rosado, A.
1989-01-01
We calculate the production of charged bosons in deep inelastic e - P scattering in the context of an electroweak model in which the vector boson self interactions may be different from those prescribed by the electroweak standard model. We present results which show the dependence of the cross section on the anomalous magnetic dipole moment κ of the W ± . We find for energies available at HERA that even small deviations from the standard model value of κ imply observable deviations in the W ± production rates. We also show that the contributions from heavy boson exchange diagrams are very important. (orig.)
Magnetic moment for the negative parity Λ→Σ0 transition in light cone QCD sum rules
Directory of Open Access Journals (Sweden)
T.M. Aliev
2016-07-01
Full Text Available The magnetic moment of the Λ→Σ0 transition between negative parity baryons is calculated in framework of the QCD sum rules approach by using the general form of the interpolating currents. The pollution arising from the positive-to-positive, and positive-to-negative parity baryons is eliminated by constructing the sum rules for different Lorentz structures. A comparison of our result with the predictions of the results of other approaches for the positive parity baryons is presented.
International Nuclear Information System (INIS)
Alexander, P.
1993-01-01
A hydromagnetic equation system for the interplanetary collisionless solar wind is used to derive a set of conservation laws for that medium. It is found that every equation of the original system, including the closure relation, is related to one conservation law. The set that has been derived does not only include the traditional laws, but also a new one for the magnetic moment of the electrons. The conservation set is then used to obtain the space constants for the solar coronal expansion. The new law yields a constant that has not been predicted by other models
The magnetic moment of {sup 209}Bi. A molecular determination of the diamagnetic shielding
Energy Technology Data Exchange (ETDEWEB)
Bastug, T. [Kassel Univ. (Gesamthochschule) (Germany). Fachbereich 18 - Physik; Fricke, B. [Kassel Univ. (Gesamthochschule) (Germany). Fachbereich 18 - Physik; Finkbeiner, M. [Kassel Univ. (Gesamthochschule) (Germany). Fachbereich 18 - Physik; Johnson, W.R. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States)
1996-07-22
Using a self-consistent relativistic molecular Dirac-Fock-Slater code we have determined the charge density and the diamagnetic shielding at the {sup 209}Bi nucleus in the molecule Bi(NO{sub 3}){sub 3}, which was used in the experiment for the g-factor. Our final value for the nuclear moment of {sup 209}Bi is {mu} {sub I}=4.1103{+-}0.0005 {mu} {sub N}. (orig.). With 1 tab.
International Nuclear Information System (INIS)
Kerimov, B.K.; Al'-Khamisi, I.M.; Safin, M.Ya.; Ishankuliev, D.
1980-01-01
Obtained were general analytical solutions for the correction of the second Born approximation to the cross section of elastic scattering of fast electrons by nuclei with provision for both pure electric and pure magnetic scatterings and a contribution resulted from their interference. The given formulae for the cross sections are written in the form independent of model representations of nuclear form factors and can be used both for light and heavy nuclei. A contribution to the cross section of the second Born approximation resulted from the interference of electron interaction with the Coulomb field as well as with nuclear magnetic dipole moment has been calculated. The stidy on the contribution of higher-order multipole momenta may be analogically carried out on the basis of the general formulae given in the Appendix
Space-time resolved measurements of spontaneous magnetic fields in laser-produced plasma
Czech Academy of Sciences Publication Activity Database
Pisarczyk, T.; Gus’kov, S.Yu.; Dudžák, Roman; Chodukowski, T.; Dostál, Jan; Demchenko, N. N.; Korneev, Ph.; Kalinowska, Z.; Kalal, M.; Renner, Oldřich; Šmíd, Michal; Borodziuk, S.; Krouský, Eduard; Ullschmied, Jiří; Hřebíček, Jan; Medřík, Tomáš; Golasowski, Jiří; Pfeifer, Miroslav; Skála, Jiří; Pisarczyk, P.
2015-01-01
Roč. 22, č. 10 (2015), č. článku 102706. ISSN 1070-664X R&D Projects: GA MŠk LM2010014; GA MŠk(CZ) LD14089; GA ČR GPP205/11/P712 Grant - others:FP7(XE) 284464 Program:FP7 Institutional support: RVO:61389021 ; RVO:68378271 Keywords : space-time resolved spontaneous magnetic field (SMF) * Laser System Subject RIV: BL - Plasma and Gas Discharge Physics; BL - Plasma and Gas Discharge Physics (FZU-D) OBOR OECD: Fluids and plasma physics (including surface physics); Fluids and plasma physics (including surface physics) (FZU-D) Impact factor: 2.207, year: 2015 http://scitation.aip.org/content/aip/journal/pop/22/10/10.1063/1.4933364
International Nuclear Information System (INIS)
Ogasawara, Masatada; Takita, Masami.
1981-08-01
Spontaneous magnetic fields due to the temperature gradient nabla T 0 produced by a focussed laser beam on one point of a pellet are taken into account in deriving the dispersion relation of Rayleigh-Taylor instability. Growth rate γ decreases with time. Density fluctuation with wavelength shorter than 1.5(R/L sub(T)) x (n sub(s)/n 0 )sup(1/2) μm is remarkably stabilized, where R, L sub(T), n sub(s) and n 0 are the radius of a pellet, L sub(T)sup(-1) = + nabla T 0 /T 0 + , number densities of solid and the pellet. Validity condition of the theory is γt 0 >> 1 or in another form R >> L, where t 0 is the time of thermal expansion of a pellet and L -1 = + nabla n 0 /n 0 + . (author)
Influence of temperature on the systematics of magnetic moments of free Fe clusters
Czech Academy of Sciences Publication Activity Database
Šipr, Ondřej; Polesya, S.; Minár, J.; Ebert, H.
2007-01-01
Roč. 19, - (2007), 446205/1-446205/10 ISSN 0953-8984 Institutional research plan: CEZ:AV0Z10100521 Keywords : magnet ism * temperature * exchange coupling * clusters Subject RIV: BM - Solid Matter Physics ; Magnet ism Impact factor: 1.886, year: 2007
Anisotropy of Magnetic Moments and Energy in Tetragonal Fe-Co Alloys from First Principles
Czech Academy of Sciences Publication Activity Database
Turek, Ilja; Kudrnovský, Josef; Carva, K.
2013-01-01
Roč. 26, č. 5 (2013), s. 1581-1584 ISSN 1557-1939 R&D Projects: GA ČR(CZ) GAP204/11/1228 Institutional support: RVO:68081723 ; RVO:68378271 Keywords : density functional theory * magnetic anisotropy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.930, year: 2013
AC Magnetic Heating of Superparamagnetic Fe and Co Nanoparticles
2012-06-01
saturation magnetization, MS. As the magnitude of the field decreases the total magnetization decreases and reaches at zero field the remanent magnetization...a spontaneous random orientation of the magnetic moment inside the particles (zero remanence magnetization and coercivity, so no hysteresis
Rodriguez, J P; Rezayi, E H
2009-08-28
A Heisenberg model over the square lattice recently introduced by Si and Abrahams to describe local-moment magnetism in the new class of Fe-As high-T(c) superconductors is analyzed in the classical limit and on a small cluster by exact diagonalization. In the case of spin-1 iron atoms, large enough Heisenberg exchange interactions between neighboring spin-1/2 moments on different iron 3d orbitals that frustrate true magnetic order lead to hidden magnetic order that violates Hund's rule. It accounts for the low ordered magnetic moment observed by elastic neutron diffraction in an undoped parent compound to Fe-As superconductors. We predict that low-energy spin-wave excitations exist at wave numbers corresponding to either hidden Néel or hidden ferromagnetic order.
Hou, Zhipeng
2017-06-07
The quest for materials hosting topologically protected skyrmionic spin textures continues to be fueled by the promise of novel devices. Although many materials have demonstrated the existence of such spin textures, major challenges remain to be addressed before devices based on magnetic skyrmions can be realized. For example, being able to create and manipulate skyrmionic spin textures at room temperature is of great importance for further technological applications because they can adapt to various external stimuli acting as information carriers in spintronic devices. Here, the first observation of skyrmionic magnetic bubbles with variable topological spin textures formed at room temperature in a frustrated kagome Fe3 Sn2 magnet with uniaxial magnetic anisotropy is reported. The magnetization dynamics are investigated using in situ Lorentz transmission electron microscopy, revealing that the transformation between different magnetic bubbles and domains is via the motion of Bloch lines driven by an applied external magnetic field. These results demonstrate that Fe3 Sn2 facilitates a unique magnetic control of topological spin textures at room temperature, making it a promising candidate for further skyrmion-based spintronic devices.
Anomalous magnetoresistance effect in sputtered TbFeCo relating to dispersed magnetic moment
International Nuclear Information System (INIS)
Yumoto, S.; Toki, K.; Okada, O.; Gokan, H.
1988-01-01
The electric resistance is sputtered TbFeCo has been measured at room temperature as a function of magnetic field perpendicular to the film plane. Two kinds of anomalous magnetoresistance have been observed. One is a magnetoresistance peak in the magnetization reversal region. The other is reversible change proportional to the applied magnetic field, appearing in the other region. The magnetoresistance peak agrees well with a curve calculated from experimental Hall loop, using a phenomenological relation between anomalous magnetoresistance and anomalous Hall voltage. The magnetoresistance peak is found to originate from magnetic domain walls. The linear magnetoresistance change for TM dominant samples appears in a direction opposite to that for RE dominant samples. The linear change can't be derived from Hall loop
Origin of Perpendicular Magnetic Anisotropy and Large Orbital Moment in Fe Atoms on MgO
Baumann, S.; Donati, F.; Stepanow, S.; Rusponi, S.; Paul, W.; Gangopadhyay, S.; Rau, I. G.; Pacchioni, G. E.; Gragnaniello, L.; Pivetta, M.; Dreiser, J.; Piamonteze, C.; Lutz, C. P.; Macfarlane, R. M.; Jones, B. A.; Gambardella, P.; Heinrich, A. J.; Brune, H.
2015-12-01
We report on the magnetic properties of individual Fe atoms deposited on MgO(100) thin films probed by x-ray magnetic circular dichroism and scanning tunneling spectroscopy. We show that the Fe atoms have strong perpendicular magnetic anisotropy with a zero-field splitting of 14.0 ±0.3 meV /atom . This is a factor of 10 larger than the interface anisotropy of epitaxial Fe layers on MgO and the largest value reported for Fe atoms adsorbed on surfaces. The interplay between the ligand field at the O adsorption sites and spin-orbit coupling is analyzed by density functional theory and multiplet calculations, providing a comprehensive model of the magnetic properties of Fe atoms in a low-symmetry bonding environment.
Annealing influence on the atomic ordering and magnetic moment in a Ni-Mn-Ga alloy
International Nuclear Information System (INIS)
Gutierrez, J.; Lazpita, P.; Barandiaran, J.M.; Fdez-Gubieda, M.L.; Chaboy, J.; Kawamura, N.
2007-01-01
We have studied an alloy of composition Ni 51 Mn 28 Ga 21 prepared by rapid quenching in the form of a ribbon, with transformation temperature T M =337 K below the magnetic-order temperature, T C =344 K. Annealing of the samples was performed at 600 K for different times. From magnetic characterization a clear increase of the saturation magnetization accompanied with an increase of T C (up to 20 K) and T M (about 10 K) has been observed. XMCD measurements of both as-quenched and annealed samples have revealed great changes for the Mn and also the existence of a strong Ni signal. These results point out a possible non-negligible role of Ni, through the polarization of the conduction band, into driving the interplay between annealing and the magnetic properties in these materials
International Nuclear Information System (INIS)
Klempt, E.; Schulze, R.; Wolf, H.; Camani, M.; Gygax, F.N.; Rueegg, W.; Schenck, A.; Schilling, H.
1982-01-01
A new determination of the magnetic moment of the positive muon in units of the magnetic moment of the proton is presented. The Larmor precession of positive muons in liquid bromine was observed by a stroboscopic technique in a field of 0.75 T and combined with concomitant proton NMR measurements in the same chemical environment. The stroboscopic method allows use of the full muon stopping rate available at the Schweizerisches Institut fuer Nuklearforschung (SIN) muon channel. Moreover, it permits an intrinsically precise determination of muon Larmor frequency and proton NMR frequency measuring the magnetic field by comparison with the stable reference frequency of the SIN accelerator (ΔΩ/Ωroughly-equal10 -8 ). Two different bromine targets were used which allowed an unambiguous determination of the chemical field shift experienced by the muons. One target contained pure and water-free liquid bromine (Br 2 ), where stopped muons form (μ + e - )Br molecules. The other target was slightly contaminated with water; there a chemical reaction chain places the muons into (μ + e - )HO molecules. The diamagnetic shielding of protons in the analogous molecules HBr and H 2 O in liquid bromine was measured by high-resolution NMR. Values for the isotopic shift of the diamagnetic shielding, when protons are replaced by muons, are available from quantum chemical calculations. After application of the chemical-shift corrections, the results from the two different bromine targets are consistent. The final result is μ/sub μ//μ/sub p/ = 3.183 344 1(17) (or +- 0.53 ppm). This value agrees with other recent precision determinations of μ/sub μ//μ/sub p/. For the muon mass the present result implies m/sub μ//m/sub e/ = 206.768 35(11)
Spontaneous magnetic fluctuations and collisionless regulation of the Earth's plasma sheet
Moya, P. S.; Espinoza, C.; Stepanova, M. V.; Antonova, E. E.; Valdivia, J. A.
2017-12-01
Even in the absence of instabilities, plasmas often exhibit inherent electromagnetic fluctuations which are present due to the thermal motion of charged particles, sometimes called thermal (quasi-thermal) noise. One of the fundamental and challenging problems of laboratory, space, and astrophysical plasma physics is the understanding of the relaxation processes of nearly collisionless plasmas, and the resultant state of electromagnetic plasma turbulence. The study of thermal fluctuations can be elegantly addressed by using the Fluctuation-Dissipation Theorem that describes the average amplitude of the fluctuations through correlations of the linear response of the media with the perturbations of the equilibrium state (the dissipation). Recently, it has been shown that solar wind plasma beta and temperature anisotropy observations are bounded by kinetic instabilities such as the ion cyclotron, mirror, and firehose instabilities. The magnetic fluctuations observed within the bounded area are consistent with the predictions of the Fluctuation-Dissipation theorem even far below the kinetic instability thresholds, with an enhancement of the fluctuation level near the thresholds. Here, for the very first time, using in-situ magnetic field and plasma data from the THEMIS spacecraft, we show that such regulation also occurs in the Earth's plasma sheet at the ion scales and that, regardless of the clear differences between the solar wind and the magnetosphere environments, spontaneous fluctuation and their collisionless regulation seem to be fundamental features of space and astrophysical plasmas, suggesting the universality of the processes.
Anomalous magnetic moments in Fe-Pt and Fe-Pd Invar alloys under high pressure
Matsushita, M; Endo, S; Ishizuka, M; Kindo, K; Ono, F
2002-01-01
Magnetization measurements have been carried out for disordered Fe sub 7 sub 2 Pt sub 2 sub 8 , Fe sub 6 sub 6 Pd sub 3 sub 4 , and Fe sub 6 sub 8 Pd sub 3 sub 2 Invar alloys under high pressure using a technique combining a pressure-clamp-type Drickamer cell and a pulse magnet. In Fe sub 7 sub 2 Pt sub 2 sub 8 at room temperature, the magnetization decreased rapidly with increasing pressure up to 2.5 GPa, but above 2.5 GPa the rate of decrease became small and remained at a small value up to 5.6 GPa. In Fe-Pd Invar alloys at room temperature, the magnetization decreased linearly with increasing pressure. But, at 4.2 K, the change of magnetization with pressure was small in Fe sub 6 sub 6 Pd sub 3 sub 4 , which means that Fe sub 6 sub 6 Pd sub 3 sub 4 behaves as a strong ferromagnet.
The measurement of magnetic moments of nuclear states of high angular momentum
International Nuclear Information System (INIS)
Goldring, G.
1978-01-01
Two problems related to the measurement of the g-factor of relevant nuclear levels and their circumvention are discussed: a) the very high magnetic fields required for the measurements, available only as a hyperfine field of electrons or other charged particles moving very close to the nucleus; b) the large angular momentum of those nuclear states. The nuclei considered are those recoiling from a nuclear reaction at high speeds in either vacuum or gas. The environment of these nuclei are the isolated ions with which they are associated. The hyperfine interaction with such ions is primarily magnetic. (B.G.)
Energy Technology Data Exchange (ETDEWEB)
Ares de Parga, G.; Ortiz D, M.; Mares, R. [Dpto de Fisica, Escuela Superior de Fisica Matematicas, Instituto Politecnico Nacional, U.P. Adolfo Lopez Mateos, Zacatenco, 07738, Mexico D.F. (Mexico)]. e-mail: gonzalo@esfm.ipn.mx
2007-07-01
Starting with the magnetic Smirnov reaction force, a relativistic equation which describe the motion of a charged particle with constant magnetic moment of spin {mu}{sup {yields}}, is obtained. A Landau-Lifshitz-like equation is deduced with magnetic moment. A fundamental difference between the classical and relativistic radiation rate of energy is found. (Author)
Search for the Neutrino Magnetic Moment in the Non-Equilibrium Reactor Antineutrino Energy Spectrum
Kopeikin, V. I.; Mikaelyan, L. A.; Sinev, V. V.
1999-01-01
We study the time evolution of the typical nuclear reactor antineutrino energy spectrum during reactor ON period and the decay of the residual antineutrino spectrum after reactor is stopped. We find that relevant variations of the soft recoil electron spectra produced via weak and magnetic ${\\widetilde {\
Magnetic moment formation due to arsenic vacancies in LaFeAsO-derived superconductors
Czech Academy of Sciences Publication Activity Database
Kikoin, K.; Drechsler, S.L.; Koepernik, K.; Málek, Jiří; van den Brink, J.
2015-01-01
Roč. 5, Jul (2015), s. 11280 ISSN 2045-2322 Institutional support: RVO:68378271 Keywords : high-temperature superconductivity , transition metal impurities * iron-based superconductors * pnictides Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 5.228, year: 2015
Energy Moment Method Applied to Nuclear Quadrupole Splitting of Nuclear Magnetic Resonance Lines
DEFF Research Database (Denmark)
Frank, V
1962-01-01
Expressions giving the sum of the energy values, raised to the second and third power, for a nucleus interacting with a static magnetic field and a static electric field gradient are derived. Several applications of this method for obtaining the values of the components of the electric field...
Energy Technology Data Exchange (ETDEWEB)
Vogel, J
2006-03-15
In this document, I use some results of my research activities of the last ten years to show the power of x-ray magnetic dichroism for determining magnetic properties of thin layers, multilayers and nano-structures. The use of sum rules for x-ray dichroism allows a quantitative determination of the spin and orbital contributions to the magnetic moment, for each element of a heterogeneous material separately. Used in a qualitative way, x-ray dichroism allows monitoring the magnetization of the different layers in a multilayer material as a function of applied field. In combination with the temporal structure of synchrotron radiation, it is possible to study fast magnetization reversal with element selectivity, which is important for devices like spin valves and magnetic tunnel junctions. Adding the spatial resolution of a photoelectron emission microscope (PEEM), it becomes possible to study all the details of the fast magnetization reversal in complex magnetic systems. (author)
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
Zhou, Biao; Idobata, Yuki; Kobayashi, Akiko; Cui, HengBo; Kato, Reizo; Takagi, Rina; Miyagawa, Kazuya; Kanoda, Kazushi; Kobayashi, Hayao
2012-08-01
Crystals of the single-component molecular conductor [Cu(dmdt)(2)] (dmdt = dimethyltetrathiafulvalenedithiolate) were prepared as a molecular system, with three-dimensionally arranged magnetic moments embedded in "sea" of π conduction electrons. [Cu(dmdt)(2)] had fairly large room-temperature conductivity (110 S cm(-1)) and exhibited weakly metallic behavior near room temperature. Below 265 K, the resistivity (R) increased very slowly with decreasing temperature and then increased rapidly, indicating a transition from a highly conducting state to an insulating state near 95 K. The magnetic susceptibility showed Curie-Weiss behavior at 100-300 K (C = 0.375 emu/mol, Θ = 180 K). The Curie constant and the high-temperature resistivity behavior indicate that conduction electrons and three-dimensionally arranged magnetic moments coexist in the crystal. The ESR intensity increased down to about 95 K. The ESR signal was broadened and decreased abruptly near 95 K, suggesting that electric and antiferromagnetic transitions occurred simultaneously near 95 K. The crystal structure was determined down to 13 K. To examine the stability of the twisted conformation of Cu complex with dithiolate ligands, the dihedral angle dependence of the conformational energy of an isolated M(L)(2)(n-) molecule was calculated, which revealed the dihedral angle dependence on the ligand (L) and the oxidation state of the molecule (n). High-pressure four-probe resistivity measurements were performed at 3.3-9.3 GPa using a diamond anvil cell. The small resistivity increase observed at 3.3 GPa below 60 K suggested that the insulating transition observed at ambient pressure near 95 K was essentially suppressed at 3.3 GPa. The intermolecular magnetic interactions were examined on the basis of simple mean field theory of antiferromagnetic transition and the calculated intermolecular overlap integrals of the singly occupied molecular orbital (SOMO) of Cu(dmdt)(2).
Volkov, Sergey
2017-11-01
This paper presents a new method of numerical computation of the mass-independent QED contributions to the electron anomalous magnetic moment which arise from Feynman graphs without closed electron loops. The method is based on a forestlike subtraction formula that removes all ultraviolet and infrared divergences in each Feynman graph before integration in Feynman-parametric space. The integration is performed by an importance sampling Monte-Carlo algorithm with the probability density function that is constructed for each Feynman graph individually. The method is fully automated at any order of the perturbation series. The results of applying the method to 2-loop, 3-loop, 4-loop Feynman graphs, and to some individual 5-loop graphs are presented, as well as the comparison of this method with other ones with respect to Monte Carlo convergence speed.
Role of magnetic resonance imaging in the diagnosis of spontaneous spondylodiscitis
International Nuclear Information System (INIS)
Cusmano, F.; Calabrese, G.; Bassi, S.; Branislav, S.; Bassi, P.
2000-01-01
Purpose of this work is to report the Magnetic Resonance Imaging (MRI) features of acute and chronic spontaneous spondylodiscitis as well as any as well as any typical patterns which can be useful for the differential diagnosis between pyogenic and tuberculous forms. Eleven patients affected with spontaneous spondylodiscitis were selected for the study; they were 7 men and 4 women ranging in age 33-87 years (mean: 64). Patients with a superconductive magnet at 1.5, with the following sequences: sagittal PD and T2-weighted TSE, sagittal T1-weighted SE, axial PD and T2-weighted TSE for the lumbar spine, axial T2-weighted GRE for the cervical and dorsal spine and axial and sagittal T1-weighted SE after contrast agent (gadolinium DTPA) injection. MR images were reviewed by three experienced radiologists and morphological and signal intensity changes of vertebral body and disk were recorded on a standard form. In 9 patients it was possible to compare MR to CT findings. Three patients had infectious diseases in other organs and 2 were diabetics. Biopsy was performed in two cases only and demonstrated Staphylococcus aureus in one and Mycobacterium tuberculosis in the other patient. MRI, allowed the correct diagnosis to be made in all cases, demonstrating the pathological involvement of the paravertebral structures and into the spinal canal earlier and more accurately than CT. A common finding in pyogenic and tuberculous spondylodiscitis was the low signal of the subcortical bone marrow on T1-weighted sagittal images, which enhanced after Gd-DTPA administration and became intermediate or high on T2-weighted images. Moreover, the steady high signal intensity of the disk on T2-weighted images and its contrast enhancement on T1-weighted images is typical for an acute inflammatory process. Based on our personal experience an literature data, it is believed that MRI is the most sensitive technique for the diagnosis of spondylodiscitis in the acute phase, whereas it is
Magnetic nanowires (Fe, Fe-Co, Fe-Ni – magnetic moment reorientation in respect of wires composition
Directory of Open Access Journals (Sweden)
Kalska-Szostko Beata
2015-03-01
Full Text Available Magnetic nanowires of Fe, Fe-Co, and Fe-Ni alloy and layered structure were prepared by electrochemical alternating current (AC deposition method. The morphology of the nanowires in and without the matrix was studied by energy dispersive X-ray spectroscopy (EDX, scanning electron microscopy (SEM, and X-ray diffraction (XRD, respectively. The wires either show strong dependence on the combination of elements deposition (alloy or layered or chemical composition (Co or Ni. The magnetic properties of the nanostructures were determined on the basis of Mössbauer spectroscopy (MS.
International Nuclear Information System (INIS)
Souza, P E N de; Oliveira, L M de; Ortiz, W A; Camargo, P C de; Oliveira, A J A de
2005-01-01
In this work we present magnetic susceptibility results for Cr-x at.% Nb alloys (x = 0.2, 0.6, 0.7, 1.4, and 2.0), showing that a local short-range order spin-density wave (L-SDW) appears at a characteristic temperature (T loc ) above the Neel temperature. The evidence for L-SDW is based on a Curie-Weiss-like behaviour, which is suppressed when large magnetic fields are applied or for alloys with Nb concentration above x = 2.0 at.%
Energy Technology Data Exchange (ETDEWEB)
Mamyrin, B.A.; Aruev, N.N.; Alekseenko, S.A.
1983-06-01
In connection with the revision of the table values of the atomic masses and the forthcoming coordination of the values of the fundamental physical constants, the result of measurement of the proton magnetic moment in nuclear Magnetons obtained in 1971 is re-examined by taking into account recent data. With the atomic masses recognized in 1982 the proton magnetic moment expressed in nuclear magnetons without a correction for diamagnetic screening of the proton in a water molecule is found to be ..mu..sub(p)'/..mu..sub(n)=2.7927729+-0.0000012 (4.3x10/sup -5/%).
Moment problems in Hilbert space with applications to magnetic resonance imaging
International Nuclear Information System (INIS)
Zwaan, Marcel.
1991-01-01
This thesis is concerned with the mathematical and computational aspects of reconstruction techniques by means of magnetic resonance imaging, in particular for the time-dependent case, referred to as dynamic MRI. The main subjects are: a mathematical framework for dynamic MRI reconstruction; analytic solutions, numerical algorithms and development of reconstruction techniques; stability analysis of the reconstruction algorithms; comparison between these algorithms. (author). 63 refs.; 38 figs.; 5 tabs
Orbital magnetic moment and extrinsic spin Hall effect for iron impurities in gold
Czech Academy of Sciences Publication Activity Database
Shick, Alexander; Kolorenč, Jindřich; Janiš, Václav; Lichtenstein, A.I.
2011-01-01
Roč. 84, č. 11 (2011), "113112-1"-"113112-4" ISSN 1098-0121 R&D Projects: GA ČR(CZ) GAP204/10/0330; GA AV ČR IAA100100912 Institutional research plan: CEZ:AV0Z10100520 Keywords : spin Hall effect * XMCD Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.691, year: 2011 http://prb.aps.org/abstract/PRB/v84/i11/e113112
Petrushin, A.; Shevkunova, A.
2018-02-01
The article deals with the investigation concentrated to optimizing the active part of the switched-reluctance motor with the aim of increasing the value of the average electromagnetic torque. Susceptibility of the average value of the electromagnetic torque to changes of the geometric dimensions of the magnetic system found in the optimization process was set.
Zhao, Qingbiao; Darriet, Jacques; Whangbo, Myung-Hwan; Ye, Longfei; Stackhouse, Chavis; zur Loye, Hans-Conrad
2011-12-28
In this paper we report the crystal growth, structure determination, and magnetic properties of the 2H-perovskite related oxides, Sr(5)Co(4)O(12) and Sr(6)Co(5)O(15), as well as the charge disproportionation and associated phase transition of Sr(5)Co(4)O(12). Sr(5)Co(4)O(12) and Sr(6)Co(5)O(15) are the (m = 2, n = 3) and (m = 1, n = 1) members of the A(3m+3n)A'(n)B(3m+n)O(9m+6n) family, respectively. Sr(6)Co(5)O(15) crystallizes in the space group R32 with lattice parameters of a = 9.5020(10) Å and c = 12.379(8) Å. The structure solution shows that Sr(6)Co(5)O(15) is isostructural with Sr(6)Rh(5)O(15). Magnetic measurements do not indicate any long-range magnetic order, although the Weiss temperature of -248 K indicates the presence of dominant antiferromagnetic interactions. Sr(5)Co(4)O(12) crystallizes in the space group P-3c1 with lattice parameters of a = 9.4705(10) Å and c = 20.063(5) Å at room temperature. The single crystal structure solution revealed that the cobalt ions in the trigonal prismatic sites of Sr(5)Co(4)O(12) undergo a structural transition at ~170 K, where the cobalt atoms are in the center of the trigonal prisms below this temperature and move partially toward the faces above this temperature. This structure transition is accompanied by a change in the magnetic moment of the oxide and can be related to a valence disproportionation of the cobalt ions and a concomitant Jahn-Teller distortion. In addition, specific heat, Seebeck coefficient, electric conductivity, and magnetic measurements as well as bond valence sum calculations were carried out for Sr(5)Co(4)O(12). Sr(5)Co(4)O(12) exhibits strong magnetic anisotropy but no long-range magnetic order. © 2011 American Chemical Society
Li, Wen-Hsien; Lee, Chi-Hung; Kuo, Chen-Chen
2016-01-01
We report on the generation of large inverse remanent magnetizations in nano-sized core/shell structure of Au/Ni by turning off the applied magnetic field. The remanent magnetization is very sensitive to the field reduction rate as well as to the thermal and field processes before the switching off of the magnetic field. Spontaneous reversal in direction and increase in magnitude of the remanent magnetization in subsequent relaxations over time were found. All of the various types of temporal relaxation curves of the remanent magnetizations are successfully scaled by a stretched exponential decay profile, characterized by two pairs of relaxation times and dynamic exponents. The relaxation time is used to describe the reduction rate, while the dynamic exponent describes the dynamical slowing down of the relaxation through time evolution. The key to these effects is to have the induced eddy current running beneath the amorphous Ni shells through Faraday induction. PMID:28773549
Energy Technology Data Exchange (ETDEWEB)
Cakirer, S. [Istanbul Sisli Etfal Hospital (Turkey). Dept. of Radiology; Karaarslan, E. [VKV American Hospital, Istanbul (Turkey). Dept. of Radiology
2004-10-01
A patient with neurofibromatosis type I (NF1) was followed-up with serial magnetic resonance imaging (MRI) studies over a period of 6 years. A contrast-enhancing lesion of the internal capsule, histologically proven to be pilocytic astrocytoma through stereotactic brain biopsy with mass effect and associated edema, was detected to reveal spontaneous involution on follow-up MRI studies. Although spontaneous regression of gliomas of the optic pathway-hypothalamus in patients with NF1 is relatively common in the literature, spontaneous involution of non-optic (i.e. areas other than optic pathways and hypothalamus) gliomas is rarely reported. Conservative management with follow-up MRI studies should be considered for non-optic glial tumors and tumor-like masses in patients with NF1, and surgical treatment should not be considered unless the lesions exhibit a rapid or unrelenting growth on serial MRI studies or produce significant clinical deterioration.
Hoopes, P. Jack; Moodie, Karen L.; Petryk, Alicia A.; Petryk, James D.; Sechrist, Shawntel; Gladstone, David J.; Steinmetz, Nicole F.; Veliz, Frank A.; Bursey, Alicea A.; Wagner, Robert J.; Rajan, Ashish; Dugat, Danielle; Crary-Burney, Margaret; Fiering, Steven N.
2017-02-01
It has recently been shown that cancer treatments such as radiation and hyperthermia, which have conventionally been viewed to have modest immune based anti-cancer effects, may, if used appropriately stimulate a significant and potentially effective local and systemic anti-cancer immune effect (abscopal effect) and improved prognosis. Using eight spontaneous canine cancers (2 oral melanoma, 3 oral amelioblastomas and 1 carcinomas), we have shown that hypofractionated radiation (6 x 6 Gy) and/or magnetic nanoparticle hyperthermia (2 X 43°C / 45 minutes) and/or an immunogenic virus-like nanoparticle (VLP, 2 x 200 μg) are capable of delivering a highly effective cancer treatment that includes an immunogenic component. Two tumors received all three therapeutic modalities, one tumor received radiation and hyperthermia, two tumors received radiation and VLP, and three tumors received only mNP hyperthermia. The treatment regimen is conducted over a 14-day period. All patients tolerated the treatments without complication and have had local and distant tumor responses that significantly exceed responses observed following conventional therapy (surgery and/or radiation). The results suggest that both hypofractionated radiation and hyperthermia have effective immune responses that are enhanced by the intratumoral VLP treatment. Molecular data from these tumors suggest Heat Shock Protein (HSP) 70/90, calreticulin and CD47 are targets that can be exploited to enhance the local and systemic (abscopal effect) immune potential of radiation and hyperthermia cancer treatment.
Relaxation of the Shallow Acceptor Center Magnetic Moment in a Highly Doped Silicon
Mamedov, T N; Herlach, D; Gorelkin, V N; Gritsaj, K I; Duginov, V N; Kormann, O; Major, J V; Stoikov, A V; Zimmermann, U
2001-01-01
Results on the temperature dependence of the residual polarization of negative muons in crystalline silicon with germanium, boron and phosphorus impurities are presented. The measurements were carried out in a magnetic field of 0.1 T transverse to the direction of the muon spin in the temperature range 4.2-300 K. It is found that in a silicon sample with a high concentration of germanium impurity (9\\cdot 10^{19} cm^{-3}), as in the samples of n- and p-type silicon with impurity concentrations up to \\sim 10^{17} cm^{-3}, the relaxation rate \
Hayasaka, Ryo; Aoshima, Masayuki; Satoh, Akira
We have investigated mainly the influences of magnetic particle-particle interactions on the orientational distribution and viscosity of a semi-dense dispersion, which is composed of rod-like particles with a magnetic moment magnetized normal to the particle axis. In addition, the influences of the magnetic field strength, shear rate, and random forces on the orientational distribution and rheological properties have been clarified. The mean field approximation has been applied to take into account magnetic interactions between rod-like particles. The basic equation of the orientational distribution function has been derived from the balance of torques and solved by the numerical analysis method. The results obtained here are summarized as follows. For a strong magnetic field, the rotational motion of the rod-like particle is restricted in a plane normal to the shearing plane since the magnetic moment of the particle is restricted in the magnetic field direction. Under circumstances of a very strong magnetic interaction between particles, the magnetic moment is strongly restricted in the magnetic field direction, so that the particle has a tendency to incline in the flow direction with the magnetic moment pointing to the magnetic field direction. For a strong shear flow, a directional characteristic of rod-like particles is enhanced, and this leads to a more significant one-peak-type distribution of the orientational distribution function. Magnetic interactions between particles do not contribute to the increase in the viscosity because the mean-field vector has only a component along the magnetic field direction.
Modulation of Jahn-Teller effect on magnetization and spontaneous electric polarization of CuFeO2
Xiao, Guiling; Xia, Zhengcai; Wei, Meng; Huang, Sha; Shi, Liran; Zhang, Xiaoxing; Wu, Huan; Yang, Feng; Song, Yujie; Ouyang, Zhongwen
2018-03-01
CuFe0.99Mn0.01O2 and CuFe0.99Co0.01O2 single crystal samples are grown by a floating zone technique and their magnetization and spontaneous electric polarization have been investigated. Similarly with pure CuFeO2, an obviously anisotropic magnetization and spontaneous electric polarization were observed in the both doped samples, and their phase transition critical fields and temperatures are directly doping ion dependent. Considering the different d-shell configuration and ionic size between Mn3+, Co3+ and Fe3+ ions, in which the Mn3+ ion with Jahn-Teller (J-T) effect has different distortion on the geometry frustration from both of Fe3+ and Co3+ ion. Since for Mn3+ ion, the orbital splitting results from the low-symmetry J-T distortion in a crystal-field environment leads to a distorted MnO6 octahedron, which different from undistorted FeO6 and CoO6 octahedrons. The strain between distorted and undistorted octahedrons produces different effects on the spin reorientation transition and spontaneous electric polarization. Although the pure CuFeO2 has a very strong and robust frustration, the presence of the strain due to the random distribution of distorted MnO6 octahedron and undistorted CoO6 (FeO6) octahedrons leads to its spin reorientation transitions and spontaneous electric polarization different from CuFeO2.
Interactions among magnetic moments in the double perovskites Sr2Fe1+xMo1−xO6
International Nuclear Information System (INIS)
Pilo, J.; Carvajal, E.; Oviedo-Roa, R.; Cruz-Irisson, M.; Navarro, O.
2014-01-01
It is well known that every double perovskite shows a characteristic magnetic behavior, as a consequence of the interactions among the magnetic moments associated with the atoms in their cells; at the same time, the electric and magnetic properties of the bulk double perovskite Sr 2 FeMoO 6 are well characterized. In this work we studied the iron rich compounds Sr 2 Fe 1+x Mo 1−x O 6 , using a supercell to model such concentrations that made Fe richer perovskites by ±66.6% and ±200%. Starting from the stoichiometric double perovskite, and modifying the Fe/Mo ratio in the compound, the study of these materials were based on the calculation of the magnetic moment at each atom, as well as the partial density of states
Energy Technology Data Exchange (ETDEWEB)
Pilo, J. [Escuela Superior de Ingeniería Mecánica y Eléctrica-Culhuacán, Instituto Politécnico Nacional Av. Santa Ana 1000, México, D. F., C. P. 04430, México (Mexico); Carvajal, E., E-mail: ecarvajalq@ipn.mx [Escuela Superior de Ingeniería Mecánica y Eléctrica-Culhuacán, Instituto Politécnico Nacional Av. Santa Ana 1000, México, D. F., C. P. 04430, México (Mexico); Oviedo-Roa, R. [Programa de Investigación en Ingeniería Molecular, Instituto Mexicano del Petróleo Eje Central Lázaro Cárdenas Norte 152, México, D. F., C. P. 07730, México (Mexico); Cruz-Irisson, M. [Escuela Superior de Ingeniería Mecánica y Eléctrica-Culhuacán, Instituto Politécnico Nacional Av. Santa Ana 1000, México, D. F., C. P. 04430, México (Mexico); Navarro, O. [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México A.P. 70-360, México, D. F., C. P. 04510, México (Mexico)
2014-12-15
It is well known that every double perovskite shows a characteristic magnetic behavior, as a consequence of the interactions among the magnetic moments associated with the atoms in their cells; at the same time, the electric and magnetic properties of the bulk double perovskite Sr{sub 2}FeMoO{sub 6} are well characterized. In this work we studied the iron rich compounds Sr{sub 2}Fe{sub 1+x}Mo{sub 1−x}O{sub 6}, using a supercell to model such concentrations that made Fe richer perovskites by ±66.6% and ±200%. Starting from the stoichiometric double perovskite, and modifying the Fe/Mo ratio in the compound, the study of these materials were based on the calculation of the magnetic moment at each atom, as well as the partial density of states.
An upper limit on the anomalous magnetic moment of the $\\tau$ lepton
Ackerstaff, K.; Allison, John; Altekamp, N.; Anderson, K.J.; Anderson, S.; Arcelli, S.; Asai, S.; Ashby, S.F.; Axen, D.; Azuelos, G.; Ball, A.H.; Barberio, E.; Barlow, Roger J.; Bartoldus, R.; Batley, J.R.; Baumann, S.; Bechtluft, J.; Behnke, T.; Bell, Kenneth Watson; Bella, G.; Bentvelsen, S.; Bethke, S.; Betts, S.; Biebel, O.; Biguzzi, A.; Bird, S.D.; Blobel, V.; Bloodworth, I.J.; Bobinski, M.; Bock, P.; Bonacorsi, D.; Boutemeur, M.; Braibant, S.; Brigliadori, L.; Brown, Robert M.; Burckhart, H.J.; Burgard, C.; Burgin, R.; Capiluppi, P.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, David G.; Chrisman, D.; Clarke, P.E.L.; Cohen, I.; Conboy, J.E.; Cooke, O.C.; Couyoumtzelis, C.; Coxe, R.L.; Cuffiani, M.; Dado, S.; Dallapiccola, C.; Dallavalle, G.Marco; Davis, R.; De Jong, S.; del Pozo, L.A.; de Roeck, A.; Desch, K.; Dienes, B.; Dixit, M.S.; Doucet, M.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Eatough, D.; Estabrooks, P.G.; Etzion, E.; Evans, H.G.; Evans, M.; Fabbri, F.; Fanfani, A.; Fanti, M.; Faust, A.A.; Feld, L.; Fiedler, F.; Fierro, M.; Fischer, H.M.; Fleck, I.; Folman, R.; Fong, D.G.; Foucher, M.; Furtjes, A.; Futyan, D.I.; Gagnon, P.; Gary, J.W.; Gascon, J.; Gascon-Shotkin, S.M.; Geddes, N.I.; Geich-Gimbel, C.; Geralis, T.; Giacomelli, G.; Giacomelli, P.; Giacomelli, R.; Gibson, V.; Gibson, W.R.; Gingrich, D.M.; Glenzinski, D.; Goldberg, J.; Goodrick, M.J.; Gorn, W.; Grandi, C.; Gross, E.; Grunhaus, J.; Gruwe, M.; Hajdu, C.; Hanson, G.G.; Hansroul, M.; Hapke, M.; Hargrove, C.K.; Hart, P.A.; Hartmann, C.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Herndon, M.; Herten, G.; Heuer, R.D.; Hildreth, M.D.; Hill, J.C.; Hillier, S.J.; Hobson, P.R.; Hocker, James Andrew; Homer, R.J.; Honma, A.K.; Horvath, D.; Hossain, K.R.; Howard, R.; Huntemeyer, P.; Hutchcroft, D.E.; Igo-Kemenes, P.; Imrie, D.C.; Ishii, K.; Jawahery, A.; Jeffreys, P.W.; Jeremie, H.; Jimack, M.; Joly, A.; Jones, C.R.; Jones, M.; Jost, U.; Jovanovic, P.; Junk, T.R.; Kanzaki, J.; Karlen, D.; Kartvelishvili, V.; Kawagoe, K.; Kawamoto, T.; Kayal, P.I.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Kirk, J.; Klier, A.; Kluth, S.; Kobayashi, T.; Kobel, M.; Koetke, D.S.; Kokott, T.P.; Kolrep, M.; Komamiya, S.; Kowalewski, Robert V.; Kress, T.; Krieger, P.; von Krogh, J.; Kyberd, P.; Lafferty, G.D.; Lahmann, R.; Lai, W.P.; Lanske, D.; Lauber, J.; Lautenschlager, S.R.; Lawson, I.; Layter, J.G.; Lazic, D.; Lee, A.M.; Lefebvre, E.; Lellouch, D.; Letts, J.; Levinson, L.; List, B.; Lloyd, S.L.; Loebinger, F.K.; Long, G.D.; Losty, M.J.; Ludwig, J.; Lui, D.; Macchiolo, A.; Macpherson, A.; Mannelli, M.; Marcellini, S.; Markopoulos, C.; Markus, C.; Martin, A.J.; Martin, J.P.; Martinez, G.; Mashimo, T.; Mattig, Peter; McDonald, W.John; McKenna, J.; Mckigney, E.A.; McMahon, T.J.; McPherson, R.A.; Meijers, F.; Menke, S.; Merritt, F.S.; Mes, H.; Meyer, J.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Mincer, A.; Mir, R.; Mohr, W.; Montanari, A.; Mori, T.; Nagai, K.; Nakamura, I.; Neal, H.A.; Nellen, B.; Nisius, R.; O'Neale, S.W.; Oakham, F.G.; Odorici, F.; Ogren, H.O.; Oh, A.; Oldershaw, N.J.; Oreglia, M.J.; Orito, S.; Palinkas, J.; Pasztor, G.; Pater, J.R.; Patrick, G.N.; Patt, J.; Perez-Ochoa, R.; Petzold, S.; Pfeifenschneider, P.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poffenberger, P.; Poli, B.; Posthaus, A.; Rembser, C.; Robertson, S.; Robins, S.A.; Rodning, N.; Roney, J.M.; Rooke, A.; Rossi, A.M.; Routenburg, P.; Rozen, Y.; Runge, K.; Runolfsson, O.; Ruppel, U.; Rust, D.R.; Sachs, K.; Saeki, T.; Sahr, O.; Sang, W.M.; Sarkisian, E.K.G.; Sbarra, C.; Schaile, A.D.; Schaile, O.; Scharf, F.; Scharff-Hansen, P.; Schieck, J.; Schleper, P.; Schmitt, B.; Schmitt, S.; Schoning, A.; Schroder, Matthias; Schumacher, M.; Schwick, C.; Scott, W.G.; Shears, T.G.; Shen, B.C.; Shepherd-Themistocleous, C.H.; Sherwood, P.; Siroli, G.P.; Sittler, A.; Skillman, A.; Skuja, A.; Smith, A.M.; Snow, G.A.; Sobie, R.; Soldner-Rembold, S.; Springer, Robert Wayne; Sproston, M.; Stephens, K.; Steuerer, J.; Stockhausen, B.; Stoll, K.; Strom, David M.; Strohmer, R.; Szymanski, P.; Tafirout, R.; Talbot, S.D.; Taras, P.; Tarem, S.; Teuscher, R.; Thiergen, M.; Thomson, M.A.; von Torne, E.; Torrence, E.; Towers, S.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turcot, A.S.; Turner-Watson, M.F.; Ueda, I.; Utzat, P.; Van Kooten, Rick J.; Vannerem, P.; Verzocchi, M.; Vikas, P.; Vokurka, E.H.; Voss, H.; Wackerle, F.; Wagner, A.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wermes, N.; White, J.S.; Wilson, G.W.; Wilson, J.A.; Wyatt, T.R.; Yamashita, S.; Yekutieli, G.; Zacek, V.; Zer-Zion, D.
1998-01-01
Using radiative Z^0 -> \\tau^+ \\tau^- \\gamma events collected with the OPAL detector at LEP at \\sqrt{s}=M_Z during 1990-95, a direct study of the electromagnetic current at the \\tau\\gamma vertex has been performed in terms of the anomalous magnetic form factor F_2 of the \\tau lepton. The analysis is based on a data sample of 1429 e^+ e^- -> \\tau^+ \\tau^- \\gamma events which are examined for a deviation from the expectation with F_2 = 0. From the non-observation of anomalous \\tau^+ \\tau^- \\gamma production a limit of -0.068 < F_2 < 0.065 is obtained. This can also be interpreted as a limit on the electric dipole form factor F_3 as -3.8 x 10^-16 e-cm < eF_3 < 3.6 x 10^-16 e-cm. The above ranges are valid at the 95% confidence level.
Determination of spin, magnetic moment and isotopic shift of neutron rich 205Hg by optical pumping
International Nuclear Information System (INIS)
Rodriguez, J.; Bonn, J.; Huber, G.; Kluge, H.J.; Otten, E.W.; European Organisation for Nuclear Research, Geneva
1975-01-01
Neutron rich 205 Hg(Tsub(1/2) = 5.2 min) was produced and on-line mass separated at the ISOLDE facility at CERN. The polarization achieved by optical pumping via the atomic line (6s 21 S 0 - 6s6p 3 P 1 , lambda = 2,537 A) was monitored by the β decay asymmetry. Hyperfine structure and isotopic shift of the 205 Hg absorption line was determined by Zeeman scanning. In addition a magnetic resoncance was performed on the polarized 205 Hg nuclei in the atomic ground state. The results are: I( 205 Hg) = 1/2 (confirmed); μ(I, 205 Hg) = 0.5915(1)μ(N) (uncorrected for diamagnetism); isotopic shift deltaν(204/205) = ν( 205 Hg) - ν( 204 Hg) = -1.8(1)GHz. μ(I) and IS are discussed briefly in the frame of current literature. (orig.) [de
Energy Technology Data Exchange (ETDEWEB)
Sosa-Hernandez, E.M. [Departamento de Matematicas Aplicadas, Facultad de Contaduria y Administration, Universidad Autonoma de San Luis Potosi, Alvaro Obregon 64, 78000 San Luis Potosi, S.L.P. (Mexico); Alvarado-Leyva, P.G. [Departamento de Fisica, Facultad de Ciencias, Universidad Autonoma de San Luis Potosi Alvaro Obregon 64, 78000 San Luis Potosi, S.L.P. (Mexico)]. E-mail: pal@galia.fc.uaslp.mx
2006-11-09
The magnetic behavior of clusters V{sub 6}-V{sub 9} in bulk Fe is determined by using an electronic Hamiltonian which includes s, p and d electrons. The spin density distribution is calculated self-consistenly in the unrestricted Hartree-Fock approximation. The local magnetic moments are obtained at V and Fe atoms; the magnetic coupling between Fe and V atoms is antiferromagnetic-like. We consider two cases, the first case correspond to non-interacting clusters, the distance between them is infinity, and the another case, when the clusters are interacting, the separation between them is finite; in the first case, the magnetic order in V{sub 6} is ferromagnetic-like whereas for V{sub 9} the magnetic order is antiferromagnetic-like, in the second case we have found that the magnetic order is not well stablished in V{sub 6}. We have found that the magnetic order in the matrix is not broken by the presence of the V atoms, although the local magnetic moments of Fe atoms at the interface cluster-matrix, are reduced respect to Fe bulk magnetization (2.22{mu} {sub B}) [e.g. {mu} {sub Fe}(5) = 1.98{mu} {sub B} in V{sub 6}; {mu} {sub Fe}(3) 1.89{mu} {sub B} in V{sub 9}].
International Nuclear Information System (INIS)
Nguen Suan Khan; Pervushin, V.N.
1975-01-01
An eikonal representation has been obtained for the amplitude of the πN-scattering in the asymptotic form into account the anomalous nucleon magnetic moment leads to the introduction of the additive term in to the eikonal phase which is responsible for the spin flip in the scattering process. The Coulomb interference is considered
Li, Chuang; Zhu, Bin; Li, Tianjun
2018-02-01
We study the naturalness, dark matter, and muon anomalous magnetic moment in the Supersymmetric Standard Models (SSMs) with a pseudo-Dirac gluino (PDGSSMs) from hybrid F- and D-term supersymmetry (SUSY) breakings. To obtain the observed dark matter relic density and explain the muon anomalous magnetic moment, we find that the low energy fine-tuning measures are larger than about 30 due to strong constraints from the LUX and PANDAX experiments. Thus, to study the natural PDGSSMs, we consider multi-component dark matter and then the relic density of the lightest supersymmetric particle (LSP) neutralino is smaller than the correct value. We classify our models into six kinds: (i) Case A is a general case, which has small low energy fine-tuning measure and can explain the anomalous magnetic moment of the muon; (ii) Case B with the LSP neutralino and light stau coannihilation; (iii) Case C with Higgs funnel; (iv) Case D with Higgsino LSP; (v) Case E with light stau coannihilation and Higgsino LSP; (vi) Case F with Higgs funnel and Higgsino LSP. We study these Cases in details, and show that our models can be natural and consistent with the LUX and PANDAX experiments, as well as explain the muon anomalous magnetic moment. In particular, all these cases except the stau coannihilation can even have low energy fine-tuning measures around 10.
Kroell, T; Leske, J
2002-01-01
Magnetic moments are an indispensable source of information on the microscopic structure of atomic nuclei. It results from the fundamental difference of the spin $g$ factors of protons and neutrons, in $sign$ and $magnitude$, $\\textit{g}_{s}(\\pi)$ = +5.586 and $g_s(\
Magnetic Moments in the Past: developing archaeomagnetic dating in the UK
Outram, Zoe; Batt, Catherine M.; Linford, Paul
2010-05-01
Magnetic studies of archaeological materials have a long history of development in the UK and the data produced by these studies is a key component of global models of the geomagnetic field. However, archaeomagnetic dating is not a widely used dating technique in UK archaeology, despite the potential to produce archaeologically significant information that directly relates to human activity. This often means that opportunities to improve our understanding of the past geomagnetic field are lost, because archaeologists are unaware of the potential of the method. This presentation discusses a project by the University of Bradford, UK and English Heritage to demonstrate and communicate the potential of archaeomagnetic dating of archaeological materials for routine use within the UK. The aims of the project were achieved through the production of a website and a database for all current and past archaeomagnetic studies carried out in the UK. The website provides archaeologists with the information required to consider the use of archaeomagnetic dating; including a general introduction to the technique, the features that can be sampled, the precision that can be expected from the dates and how much it costs. In addition, all archaeomagnetic studies carried out in the UK have been collated into a database, allowing similar studies to be identified on the basis of the location of the sites, the archaeological period and type of feature sampled. This clearly demonstrates how effective archaeomagnetic dating has been in different archaeological situations. The locations of the sites have been mapped using Google Earth so that studies carried out in a particular region, or from a specific time period can be easily identified. The database supports the continued development of archaeomagnetic dating in the UK, as the data required to construct the secular variation curves can be extracted easily. This allows the curves to be regularly updated following the production of new
International Nuclear Information System (INIS)
Aoyama, Tatsumi; Hayakawa, Masashi; Kinoshita, Toichiro; Nio, Makiko
2011-01-01
This paper reports the values of contributions to the electron g-2 from 300 Feynman diagrams of the gauge-invariant Set III(a) and 450 Feynman diagrams of the gauge-invariant Set III(b). The evaluation is carried out in two versions. Version A is to start from the sixth-order magnetic anomaly M 6 obtained in the previous work. The mass-independent contributions of Set III(a) and Set III(b) are 2.1275(2) and 3.3271(6) in units of (α/π) 5 , respectively. Version B is based on the recently developed automatic code generation scheme. This method yields 2.1271(3) and 3.3271(8) in units of (α/π) 5 , respectively. They are in excellent agreement with the results of the first method within the uncertainties of numerical integration. Combining these results as statistically independent we obtain the best values, 2.1273(2), and 3.3271(5) times (α/π) 5 , for the mass-independent contributions of the Set III(a) and Set III(b), respectively. We have also evaluated mass-dependent contributions of diagrams containing muon and/or tau-particle loop. Including them the total contribution of Set III(a) is 2.1349(2) and that of Set III(b) is 3.3299(5) in units of (α/π) 5 . The total contributions to the muon g-2 of various leptonic vacuum-polarization loops of Set III(a) and Set III(b) are 112.418(32) and 15.407(5) in units of (α/π) 5 , respectively.
Calculation of the orbital magnetic moments in fcc 3d-4d binary clusters: Co-Rh and Co-Pd
Energy Technology Data Exchange (ETDEWEB)
Munoz-Navia, M [Instituto de Fisica, Universidad Autonoma de San Luis Potosi, San Luis Potosi (Mexico); Dorantes-Davila, J [Instituto de Fisica, Universidad Autonoma de San Luis Potosi, San Luis Potosi (Mexico); Pastor, G M [Laboratoire de Physique Quantique, UMR 5626 du CNRS, Universite Paul Sabatier, Toulouse (France)
2004-06-09
The orbital magnetic moments () of mixed fcc Co{sub N}Pd{sub M} and Co{sub N}Rh{sub M} (N,M = 19,24) clusters are determined by using a self-consistent real-space tight binding method. In all cases considered, + induced at the Pd and Rh atoms, which amount to about 20% of M{sub z} (2{sub Pd,Rh}=0.1-0.8 {mu}{sub B} and to a considerable enhancement of the orbital moments
International Nuclear Information System (INIS)
Azuma, Toshiya; Kodama, Takao; Yano, Takanori; Suzuki, Masayuki; Kimura, Tokunori; Tamaribuchi, Youko
2010-01-01
Hybrid of opposite-contrast (HOP) magnetic resonance angiography (MRA) is a new method that combines the advantages of 3-dimensional (3D) time-of-flight (TOF) MRA and black-blood (BB) MRA without prolonging acquisition time. In phantom and clinical studies, we focused on image differences when we applied gradient moment nulling (GMN) to 2 or 3 axes in the first echo. We made an original phantom with a semicircular tube of 3- and 5-mm internal diameter, with flow rate in the tube of 0, 20, 60, 80, or 120 cm/s. In original images of the phantom obtained with TOF MRA and flow-sensitive BB MRA and in filter frequency-weighted subtraction (FWS) processed images acquired with HOP MRA, we measured the contrast-to-noise ratio (CNR) of both the inside and outside of the tubes. In FWS processed images with GMN applied to 2 axes, the CNR was high at various flow rates in both straight and bending portions of the tubes in comparison with TOF images. In a clinical study in 15 patients, we evaluated vessel visualization in images obtained using conventional TOF MRA with magnetization transfer contrast (MTC) and HOP MRA. In clinical studies, visualization scores of HOP MRA were equivalent to those of conventional TOF MRA in the bilateral internal carotid arteries (ICA) and inferior in the basilar arteries. However, visualization of the peripheral portion of the middle cerebral artery (MCA) improved significantly in HOP MRA with GMN applied to 2 and 3 axes. Visualization of the main trunk of the ICA and MCA was superior in HOP MRA with GMN applied to 2 axes. HOP MRA with 2-axis GMN may be useful for excellent visualization of both major arteries and peripheral vessels in the head. (author)
The {sup 51}Cr and {sup 90}Sr sources in BOREXINO as tool for neutrino magnetic moment searches
Energy Technology Data Exchange (ETDEWEB)
Ianni, A. [L`Aquila Univ. (Italy). Dept. of Physics]|[LNGS, L`Aquila (Italy); Montanino, D. [INFN, Istituto Nazionale di Fisica Nucleare, Bari (Italy)]|[Bari Univ. (Italy). Dip. di Fisica
1998-06-01
The expected number of events in BOREXINO for {nu}{sub e}({nu}{sup -}{sub e})e{sup -} scattering using both a {sup 51}Cr neutrino source and a {sup 90}Sr-{sup 90}Y antineutrino source with an activity of {approx}2 MCi are presented. The background solar {nu} rates (source-off) are estimated for different scenarios. Then, it`s evaluated the possibility of BOREXINO to detect a small neutrino magnetic moment by means of the above mentioned sources. Sensitivity to 0.5 / 0.6{center_dot}10{sup -10}{mu}{sub B} (90% C.L.) can be reached using the {sup 51}Cr source in less than 100 days of data taking in the signal region T belongs to (0.25, 0.7)MeV, where T=recoil energy, while a sensitivity to 0.3{center_dot}10{sup -10}{mu}{sub B} (90% C.L.) can be reached using the {sup 90}Sr antineutrino source in the signal region T belongs to (0.25, 1.0) MeV.
Colangelo, Gilberto; Hoferichter, Martin; Procura, Massimiliano; Stoffer, Peter
2017-06-09
We present a first model-independent calculation of ππ intermediate states in the hadronic-light-by-light (HLBL) contribution to the anomalous magnetic moment of the muon (g-2)_{μ} that goes beyond the scalar QED pion loop. To this end, we combine a recently developed dispersive description of the HLBL tensor with a partial-wave expansion and demonstrate that the known scalar-QED result is recovered after partial-wave resummation. Using dispersive fits to high-statistics data for the pion vector form factor, we provide an evaluation of the full pion box a_{μ}^{π box}=-15.9(2)×10^{-11}. We then construct a suitable input for the γ^{*}γ^{*}→ππ helicity partial waves, based on a pion-pole left-hand cut and show that for the dominant charged-pion contribution, this representation is consistent with the two-loop chiral prediction and the COMPASS measurement for the pion polarizability. This allows us to reliably estimate S-wave rescattering effects to the full pion box and leads to our final estimate for the sum of these two contributions a_{μ}^{π box}+a_{μ,J=0}^{ππ,π-pole LHC}=-24(1)×10^{-11}.
Yang, X.F.; Xie, L.; Babcock, C.; Billowes, J.; Bissell, M.L.; Blaum, K.; Cheal, B.; Flanagan, K.T.; Garcia Ruiz, R. F.; Gins, W.; Gorges, C.; Grob, L.K.; Heylen, H.; Kaufmann, S.; Kowalska, M.; Kraemer, J.; Malbrunot-Ettenauer, S.; Neugart, R.; Neyens, G.; Nörtershäuser, W.; Papuga, J.; Sánchez, R.; Yordanov, D.T.
2016-01-01
Collinear laser spectroscopy has been performed on the $^{79}_{30}$Zn$_{49}$ isotope at ISOLDE-CERN. The existence of a long-lived isomer with a few hundred milliseconds half-life was confirmed, and the nuclear spins and moments of the ground and isomeric states in $^{79}$Zn as well as the isomer shift were measured. From the observed hyperfine structures, spins $I = 9/2$ and $I = 1/2$ are firmly assigned to the ground and isomeric states. The magnetic moment $\\mu$ ($^{79}$Zn) = $-$1.1866(10) $\\mu_{\\rm{N}}$, confirms the spin-parity $9/2^{+}$ with a $\
Tang, Angcang; Chen, Taolin; Zhang, Junran; Gong, Qiyong; Liu, Longqian
2017-09-01
To explore the abnormality of spontaneous activity in patients with anisometropic amblyopia under resting-state functional magnetic resonance imaging (Rs-fMRI). Twenty-four participants were split into two groups. The anisometropic amblyopia group had 10 patients, all of whom had anisometropic amblyopia of the right eye, and the control group had 14 healthy subjects. All participants underwent Rs-fMRI scanning. Measurement of amplitude of low frequency fluctuations of the brain, which is a measure of the amplitudes of spontaneous brain activity, was used to investigate brain changes between the anisometropic amblyopia and control groups. Compared with an age- and gender-matched control group, the anisometropic amblyopia group showed increased amplitude of low frequency fluctuations of spontaneous brain activity in the left superior temporal gyrus, the left inferior parietal lobe, the left pons, and the right inferior semi-lunar lobe. The anisometropic amblyopia group also showed decreased amplitude of low frequency fluctuations in the bilateral medial frontal gyrus. This study demonstrated abnormal spontaneous brain activities in patients with anisometropic amblyopia under Rs-fMRI, and these abnormalities might contribute to the neuropathological mechanisms of anisometropic amblyopia. [J Pediatr Ophthalmol Strabismus. 2017;54(5):303-310.]. Copyright 2017, SLACK Incorporated.
Ward, Thomas
2013-10-01
A new electromagnetic neutral-current quark mixing matrix, analog to the well-known Cabibbo-Kobayashi-Maskawa (CKM) weak charge-current matrix, is proposed to account for the strange quark content of the neutron and proton and part of the anomalous axial vector magnetic moments. The EM-CKM matrix is shown to be equivalent to the weak-CKM matrix following an EM to weak gauge symmetry transformation, demonstrating the universality of the Standard Model (SM) CKM quark mixing matrix. The electric and magnetic form factors are reformulated using a new QCD three quark nucleon gyromagnetic factor, Dirac and Pauli form factors and anomalous kappa factors. The old 1943 Jauch form factors which have been systematically used and developed for many years is shown to be in stark disagreement with the new global set of experimental polarized electron-proton scattering data whereas the reformulated SM parameter set of this study is shown to agree very well, lending strong support for this new EM SM approach.
International Nuclear Information System (INIS)
Bhattacharya, Somesh Kr; Tanaka, Shingo; Kohyama, Masanori; Shiihara, Yoshinori
2013-01-01
We present first-principle calculations on symmetric tilt grain boundaries (GBs) in bcc Fe. Using density functional theory (DFT), we studied the structural, electronic and magnetic properties of Σ3(111) and Σ11(332) GBs formed by rotation around the [110] axis. The optimized structures, GB energies and GB excess free volumes are consistent with previous DFT and classical simulation studies. The GB configurations can be interpreted by the structural unit model as given by Nakashima and Takeuchi (2000 ISIJ 86 357). Both the GBs are composed of similar structural units of three- and five-membered rings with different densities at the interface according to the rotation angle. The interface atoms with larger atomic volumes reveal higher magnetic moments than the bulk value, while the interface atoms with shorter bond lengths have reduced magnetic moments in each GB. The charge density and local density of states reveal that the interface bonds with short bond lengths have more covalent nature, where minority-spin electrons play a dominant role as the typical nature of ferromagnetic Fe. In order to understand the structural stability of these GBs, we calculated the local energy and local stress for each atomic region using the scheme of Shiihara et al (2010 Phys. Rev. B 81 075441). In each GB, the interface atoms with larger atomic volumes and enhanced magnetic moments reveal larger local energy increase and tensile stress. The interface atoms constituting more covalent-like bonds with reduced magnetic moments have lower local energy increase, contributing to the stabilization, while compressive stress is generated at these atoms. The relative stability between the two GBs can be understood by the local energies at the structural units. The local energy and local stress analysis is a powerful tool to investigate the structural properties of GBs based on the behavior of valence electrons. (paper)
Energy Technology Data Exchange (ETDEWEB)
Ferrer, R., E-mail: Rafael.Ferrer@fys.kuleuven.be [KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Bree, N.; Cocolios, T.E.; Darby, I.G.; De Witte, H.; Dexters, W.; Diriken, J.; Elseviers, J. [KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Franchoo, S. [Institut de Physique Nucléaire (IPN) d' Orsay, 91406 Orsay Cedex (France); Huyse, M. [KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Kesteloot, N. [KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, B-3001 Leuven (Belgium); SCK-CEN, Studiecentrum voor Kernenergie – Centre d' Etude de l' énergie Nucléaire, Mol B-2400 (Belgium); Kudryavtsev, Yu.; Pauwels, D.; Radulov, D.; Roger, T. [KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Savajols, H. [GANIL, CEA/DSM-CNRS/IN2P3, B.P. 55027, 14076 Caen (France); Van Duppen, P.; Venhart, M. [KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, B-3001 Leuven (Belgium)
2014-01-20
In-gas-cell laser ionization spectroscopy studies on the neutron deficient {sup 97–101}Ag isotopes have been performed with the LISOL setup. Magnetic dipole moments and mean-square charge radii have been determined for the first time with the exception of {sup 101}Ag, which was found in good agreement with previous experimental values. The reported results allow tentatively assigning the spin of {sup 97,99}Ag to 9/2 and confirming the presence of an isomeric state in these two isotopes, whose collapsed hyperfine structure suggests a spin of 1/2 . The effect of the N=50 shell closure is not only manifested in the magnetic moments but also in the evolution of the mean-square charge radii of the isotopes investigated, in accordance with the spherical droplet model predictions.
Energy Technology Data Exchange (ETDEWEB)
Sanctis, M. de [Universidad Nacional de Colombia, Bogota (Colombia); Ferretti, J. [Universita La Sapienza, Dipartimento di Fisica, Roma (Italy); INFN, Roma (Italy); Santopinto, E.; Vassallo, A. [INFN, Sezione di Genova, Genova (Italy)
2016-05-15
The relativistic interacting quark-diquark model of baryons, recently developed, is here extended introducing in the mass operator a spin-isospin transition interaction. This refined version of the model is used to calculate the non-strange baryon spectrum. The results are compared to the present experimental data. A preliminary calculation of the magnetic moments of the proton and neutron is also presented. (orig.)
International Nuclear Information System (INIS)
Antony, M.S.; Britz, J.
1986-01-01
A compilation of experimental root-mean square radii, isotope shifts, ground-state magnetic dipole and electric quadrupole moments of nuclei 1≤A≤239 is presented. Shell, sub-subshell closures and changes in nuclear deformations discernible from data are displayed graphically. The nuclear charge distribution, for 1≤A≤ 239 nuclei deduced from Coulomb displacement energies is shown for comparison
Ugai, M.
1996-11-01
The temporal dynamics of a large-scale magnetic loop is numerically studied on the basis of the two-dimensional spontaneous fast reconnection model. When a plasmoid, caused by the fast reconnection, propagates and collides with a wall boundary, across which plasma cannot flow, a large-scale magnetic loop is formed. The resulting magnetic loop is constructed by the reconnected field lines; inside the loop, the plasma, initially residing in the current sheet, is confined. As the reconnected field lines are piled up, the magnetic loop grows and swells outwards, so that a strong fast shock suddenly builds up at the interface between the growing loop and the strong reconnection jet. The fast shock, located ahead of the loop top, moves outwards with the growing loop, changing its strength with several peak and bottom Mach numbers. Accordingly, a localized spot-like region, where the plasma pressure is extremely enhanced, definitely comes out immediately ahead of the loop top. Along the loop side boundary, slow shocks stand, so that the resulting large-scale magnetic loop provides a very powerful energy converter in the sense that it is enclosed by slow and fast shocks.
Energy Technology Data Exchange (ETDEWEB)
Kolesnikov, A.G. [Laboratory of Thin Film Technologies, School of Natural Sciences, Far Eastern Federal University, Vladivostok 690950 (Russian Federation); Samardak, A.S., E-mail: samardak.as@dvfu.ru [Laboratory of Thin Film Technologies, School of Natural Sciences, Far Eastern Federal University, Vladivostok 690950 (Russian Federation); Stebliy, M.E.; Ognev, A.V.; Chebotkevich, L.A. [Laboratory of Thin Film Technologies, School of Natural Sciences, Far Eastern Federal University, Vladivostok 690950 (Russian Federation); Sadovnikov, A.V.; Nikitov, S.A. [Laboratory “Metamaterials,” Saratov State University, Saratov 410012 (Russian Federation); Kotel' nikov Institute of Radioengineering and Electronics, Russian Academy of Sciences, Moscow 125009 (Russian Federation); Kim, Yong Jin; Cha, In Ho [Department of Materials Science and Engineering, Korea University, Seoul 02841 (Korea, Republic of); Kim, Young Keun, E-mail: ykim97@korea.ac.kr [Department of Materials Science and Engineering, Korea University, Seoul 02841 (Korea, Republic of)
2017-05-01
One of the major societal challenges is reducing the power consumption of information technology (IT) devices and numerous data centers. Distinct from the current approaches based on switching of magnetic single-domain nanostructures or on movement of domain walls under high currents, an original magnetic skyrmion technology offers ultra-low power, fast, high-density, and scalable spintronic devices, including non-volatile random access memory. Using data-driven micromagnetic simulations, we demonstrate the possibility of spontaneous nucleation and stabilization of different skyrmionic states, such as skyrmions, merons, and meron-like configurations, in heavy metal/ferromagnetic nanodisks with the interfacial Dzyaloshinskii–Moriya interaction (iDMI) as a result of quasi-static magnetization reversal only. Since iDMI is not easily modulated in real systems, we show that skyrmion stabilization is easily achievable by manipulating magnetic anisotropy, saturation magnetization, and the diameters of nanodisks. The state diagrams, presented in terms of the topological charge, allow to explicitly distinguish the intermediate states between skyrmions and merons and can be used for developing a skyrmionic medium, which has been recently proposed to be a building block for future spin-orbitronic devices.
Dong, Li; Li, Hechun; He, Zhongqiong; Jiang, Sisi; Klugah-Brown, Benjamin; Chen, Lin; Wang, Pu; Tan, Song; Luo, Cheng; Yao, Dezhong
2016-11-01
The purpose of this study was to investigate the local spatiotemporal consistency of spontaneous brain activity in patients with frontal lobe epilepsy (FLE). Eyes closed resting-state functional magnetic resonance imaging (fMRI) data were collected from 19 FLE patients and 19 age- and gender-matched healthy controls. A novel measure, named FOur-dimensional (spatiotemporal) Consistency of local neural Activities (FOCA) was used to assess the spatiotemporal consistency of local spontaneous activity (emphasizing both local temporal homogeneity and regional stability of brain activity states). Then, two-sample t test was performed to detect the FOCA differences between two groups. Partial correlations between the FOCA values and durations of epilepsy were further analyzed. Compared with controls, FLE patients demonstrated increased FOCA in distant brain regions including the frontal and parietal cortices, as well as the basal ganglia. The decreased FOCA was located in the temporal cortex, posterior default model regions, and cerebellum. In addition, the FOCA measure was linked to the duration of epilepsy in basal ganglia. Our study suggested that alterations of local spontaneous activity in frontoparietal cortex and basal ganglia was associated with the pathophysiology of FLE; and the abnormality in frontal and default model regions might account for the potential cognitive impairment in FLE. We also presumed that the FOCA measure had potential to provide important insights into understanding epilepsy such as FLE.
International Nuclear Information System (INIS)
Glendening, E.D.; Feller, D.; Peterson, K.A.; McCullough, E.A. Jr.; Miller, R.J.
1995-01-01
The dipole moment and magnetic hyperfine properties of the A 2 Σ + Rydberg state of nitric oxide have been evaluated at a variety of levels of theory with extended correlation consistent basis sets. Using the finite field approach to compute the dipole moment, restricted coupled cluster RCCSD(T) and complete active space-configuration interaction CAS-CI+Q methods yield values (1.09--1.12 D) that are essentially identical to experiment. In contrast, dipole moments computed as an expectation value of the dipole moment operator typically differ from experiment by 0.1--0.6 D. The rather unfavorable comparisons with experiment reported in previous theoretical studies may stem, in part, from the method chosen to evaluate the dipole moment. Magnetic hyperfine properties were evaluated using a variety of unrestricted and restricted open-shell Hartree--Fock-based methods. We estimated the full CI limiting properties by exploiting the convergence behavior of a sequence of MRCI wave functions. The isotropic component A iso ( 14 N) of 39±1 MHz evaluated in this fashion is in excellent accord with the experimental value of 41.4±1.7 MHz. Highly correlated UHF-based methods [e.g., CCSD(T) and QCISD(T)] yield comparable values of 40--41 MHz that are in good agreement with both experiment and the apparent full CI limit. However, for A iso ( 17 O), the full CI limit (-97±2 MHz) and the UHF-based results (ca.-118 MHz) differ by roughly 20 MHz. It remains unclear how to reconcile this large discrepancy. copyright 1995 American Institute of Physics
Energy Technology Data Exchange (ETDEWEB)
Carey, R. M.; Lynch, K. R.; Miller, J. P.; Roberts, B. L.; Morse, W. M.; Semertzides, Y. K.; Druzhinin, V. P.; Khazin, B. I.; Koop, I. A.; Logashenko, I. [et al.; Redin, S. I.
2009-02-01
We propose to measure the muon anomalous magnetic moment, a{sub {mu}}, to 0.14 ppm-a fourfold improvement over the 0.54 ppm precision obtained in the BNL experiment E821. The muon anomaly is a fundamental quantity and its precise determination will have lasting value. The current measurement was statistics limited, suggesting that greater precision can be obtained in a higher-rate, next-generation experiment. We outline a plan to use the unique FNAL complex of proton accelerators and rings to produce high-intensity bunches of muons, which will be directed into the relocated BNL muon storage ring. The physics goal of our experiment is a precision on the muon anomaly of 16 x 10{sup -11}, which will require 21 times the statistics of the BNL measurement, as well a factor of 3 reduction in the overall systematic error. Our goal is well matched to anticipated advances in the worldwide effort to determine the standard model (SM) value of the anomaly. The present comparison, {Delta}a{sub {mu}} (Expt: -SM) = (295 {+-} 81) x 10{sup -11}, is already suggestive of possible new physics contributions to the muon anomaly. Assuming that the current theory error of 51 x 10{sup -11} is reduced to 30 x 10{sup -11} on the time scale of the completion of our experiment, a future {Delta}a{sub {mu}} comparison would have a combined uncertainty of {approx} 34 x 10{sup -11}, which will be a sensitive and complementary benchmark for proposed standard model extensions. The experimental data will also be used to improve the muon EDM limit by up to a factor of 100 and make a higher-precision test of Lorentz and CPT violation. We describe in this Proposal why the FNAL complex provides a uniquely ideal facility for a next-generation (g-2) experiment. The experiment is compatible with the fixed-target neutrino program; indeed, it requires only the unused Booster batch cycles and can acquire the desired statistics in less than two years of running. The proton beam preparations are largely aligned
Paul R. Reed; Carol J. Cumber
2000-01-01
In October, 1996 Private Moments, an adult novelty store, opened for business in Huntsville, Texas. Huntsville had no ordinances in place to prevent the opening of this type of business. In fact, the local Small Business Development Center provided guidance and assistance to Edward Delagarza, the founder and owner of Private Moments. Many of the Huntsville citizens, unhappy with the opening of Private Moments, approached the City Council requesting that it be closed immediately and asked for ...
Brown, P J; Neumann, K U; Smith, J G; Ziebeck, K R A
1997-01-01
The antiferromagnetic structure of the intermetallic compound U sub 1 sub 4 Au sub 5 sub 1 has been determined from neutron polarimetric measurements and refined by combining these data with integrated intensity measurements. The structure was found to be non-collinear with the U moments confined to the a-b plane. The moments of U atoms in each of the two sets of sixfold sites are arranged hexagonally with rotations of 60 deg. between them and the two sets are rotated with respect to one another by 50 deg. The third (twofold) set of U atoms has no ordered moment. These conclusions are in disagreement with a previous determination of the structure from powder data which gave a collinear structure with moments parallel to the c axis. Magnetization measurements made on single crystals in the temperature range 300-2 K can be understood in terms of a transition to a non-collinear easy plane antiferromagnetic structure stable below 22 K. Polarized neutron measurements have been used to determine the contribution of...
International Nuclear Information System (INIS)
Bodryakov, V.Yu.; Povzner, A.A.; Zelyukova, O.G.
1999-01-01
A thermodynamic approach to the description of magnetic contribution into ferromagnetic metals elastic modulus variations is developed on the basis of the Landau second type phase transitions theory. It is shown that the magnetostriction variation of not considered previously Landau's thermodynamic parameters α and β is an essential reason for all-round compression elastic modulus varying with magnetization. In addition, to detect the magnetic contribution into the elastic modulus from experimental data an expression is derived for its temperature dependence in a paramagnetic developed and experimental data is made for a ferromagnetic phase of gadolinium [ru
DEFF Research Database (Denmark)
Juul-Kristensen, B.; Bojsen-Møller, Finn; Holst, E.
2000-01-01
Anatomy, biomechanics, cross-section, magnetic resonance imaging, method comparison, rotator cuff muscles, ultrasound......Anatomy, biomechanics, cross-section, magnetic resonance imaging, method comparison, rotator cuff muscles, ultrasound...
Energy Technology Data Exchange (ETDEWEB)
Gravador, E.; Yoshiki, Hajime; Feizeng, H. [Ibaraki Univ., Mito (Japan)
1996-08-01
A superthermal UCN edm measuring machine is currently under construction at KEK. It utilizes a magnetically shielded superconducting solenoid at liquid helium temperature to generate a stable and homogeneous magnetic field at 10 milligauss. The design of the magnetic shield and solenoid and preliminary evaluation of shielding effectiveness is presented. (author)
International Nuclear Information System (INIS)
Gravador, E.; Yoshiki, Hajime; Feizeng, H.
1996-01-01
A superthermal UCN edm measuring machine is currently under construction at KEK. It utilizes a magnetically shielded superconducting solenoid at liquid helium temperature to generate a stable and homogeneous magnetic field at 10 milligauss. The design of the magnetic shield and solenoid and preliminary evaluation of shielding effectiveness is presented. (author)
2012-01-01
A novel magnetically recoverable Au nanocatalyst was fabricated by spontaneous green synthesis of Au nanoparticles on the surface of gum arabic-modified Fe3O4 nanoparticles. A layer of Au nanoparticles with thickness of about 2 nm was deposited on the surface of gum arabic-modified Fe3O4 nanoparticles, because gum arabic acted as a reducing agent and a stabilizing agent simultaneously. The resultant magnetically recoverable Au nanocatalyst exhibited good catalytic activity for the reduction of 4-nitrophenol with sodium borohydride. The rate constants evaluated in terms of pseudo-first-order kinetic model increased with increase in the amount of Au nanocatalyst or decrease in the initial concentration of 4-nitrophenol. The kinetic data suggested that this catalytic reaction was diffusion-controlled, owing to the presence of gum arabic layer. In addition, this nanocatalyst exhibited good stability. Its activity had no significant decrease after five recycles. This work is useful for the development and application of magnetically recoverable Au nanocatalyst on the basis of green chemistry principles. PMID:22713480
Directory of Open Access Journals (Sweden)
L. C. Xue
2015-09-01
Full Text Available Powder samples of the spinel ferrites MxNi0.7−xFe2.3O4 (M = Cr, Co and 0.0 ≤ x ≤ 0.3 and CrxNi0.7Fe2.3−xO4 (0.0 ≤ x ≤ 0.3 were synthesized using the chemical co-precipitation method. The XRD spectra confirmed that the samples had a single-phase cubic spinel structure. Magnetic measurements showed that the magnetic moments (μexp per formula both at 10 K and 300 K increased with Co substitution, while the values of μexp decreased with Cr substitution. Applying the assumption that the magnetic moments of Cr2+ and Cr3+ lie antiparallel to those of the divalent and trivalent Fe, Co, and Ni cations in the same sublattice of spinel ferrites, these interesting behaviors could be easily interpreted. The cation distributions of the three series of samples were estimated successfully by fitting the dependences of μexp, measured at 10 K, on the doping level x, using a quantum-mechanical potential barrier model earlier proposed by our group. The results obtained for the Cr cation distributions at the (A and [B] sites are very close to those obtained elsewhere using neutron diffraction.
International Nuclear Information System (INIS)
Irfan, M.; Lohman, B.; McKinney, A.M.
2009-01-01
Spontaneous thrombosis of a vein of Galen aneurysmal malformation (VOGM) is rare. We describe a 2-month-old patient with a patent VOGM and hydrocephalus, also confirmed patent at 6 months, but with subsequent lack of filling on pre-embolization catheter digital subtraction angiography (DSA) at 9 months' age. Due to the presence of T1- and T2-bright signal, noncontrast T1-weighted images (T1WI), T2-weighted images (T2WI), two-dimensional (2D) time-of-flight (TOF) magnetic resonance venography (MRV), and postcontrast T1WI were ambiguous for patency. However, subtracting the pre- from the postcontrast MRV images confirmed closure compared to subtracted images at 6 months' age. The factors contributing to thrombosis were likely a combination of a disproportionately small straight sinus, ventriculostomy, and contrast medium from DSA
Steffen, Frank; Kircher, Patrick R; Dennler, Matthias
2014-03-15
A 3-year-old French Bulldog was evaluated because of acute signs of back pain and spastic paraparesis. Neuroanatomic localization indicated a lesion in the T3-L3 spinal cord segment. Magnetic resonance imaging revealed extradural spinal cord compression at the ventral right aspect of the intervertebral disk space L3-4. On the basis of these findings, a diagnosis of sequestrated Hansen type 1 disk extrusion without extradural hemorrhage was made. The dog was treated conservatively with cage rest, restricted exercise on a leash, and NSAIDs. Results of follow-up examination 5 weeks later indicated complete resolution of clinical signs, and results of repeated MRI indicated a 69% reduction in the volume of the herniated disk material. Findings for the dog of this report indicated spinal cord compression attributable to extruded intervertebral disk material resolved. Functional improvements in dogs with such problems may be partly attributable to spontaneous regression of intervertebral disk extrusions.
Energy Technology Data Exchange (ETDEWEB)
Irfan, M.; Lohman, B.; McKinney, A.M. (Dept. of Radiology/Neuroradiology, Univ. of Minnesota, Minneapolis, Minnesota (United States))
2009-08-15
Spontaneous thrombosis of a vein of Galen aneurysmal malformation (VOGM) is rare. We describe a 2-month-old patient with a patent VOGM and hydrocephalus, also confirmed patent at 6 months, but with subsequent lack of filling on pre-embolization catheter digital subtraction angiography (DSA) at 9 months' age. Due to the presence of T1- and T2-bright signal, noncontrast T1-weighted images (T1WI), T2-weighted images (T2WI), two-dimensional (2D) time-of-flight (TOF) magnetic resonance venography (MRV), and postcontrast T1WI were ambiguous for patency. However, subtracting the pre- from the postcontrast MRV images confirmed closure compared to subtracted images at 6 months' age. The factors contributing to thrombosis were likely a combination of a disproportionately small straight sinus, ventriculostomy, and contrast medium from DSA.
Pitcher, Michael J; Mandal, Pranab; Dyer, Matthew S; Alaria, Jonathan; Borisov, Pavel; Niu, Hongjun; Claridge, John B; Rosseinsky, Matthew J
2015-01-23
Crystalline materials that combine electrical polarization and magnetization could be advantageous in applications such as information storage, but these properties are usually considered to have incompatible chemical bonding and electronic requirements. Recent theoretical work on perovskite materials suggested a route for combining both properties. We used crystal chemistry to engineer specific atomic displacements in a layered perovskite, (Ca(y)Sr(1- y))(1.15)Tb(1.85)Fe2O7, that change its symmetry and simultaneously generate electrical polarization and magnetization above room temperature. The two resulting properties are magnetoelectrically coupled as they arise from the same displacements. Copyright © 2015, American Association for the Advancement of Science.
Energy Technology Data Exchange (ETDEWEB)
Burger, Florian; Hotzel, Grit [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Feng, Xu [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki (Japan); Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Petschlies, Marcus [The Cyprus Institute, Nicosia (Cyprus); Renner, Dru B. [Jefferson Lab, Newport News, VA (United States)
2013-12-15
We present results for the leading order QCD correction to the anomalous magnetic moment of the muon including the first two generations of quarks as dynamical degrees of freedom. Several light quark masses are examined in order to yield a controlled extrapolation to the physical pion mass. We analyse ensembles for three different lattice spacings and several volumes in order to investigate lattice artefacts and finite-size effects, respectively. We also provide preliminary results for this quantity for two flavours of mass-degenerate quarks at the physical value of the pion mass.
Energy Technology Data Exchange (ETDEWEB)
Burger, Florian [Humboldt U. Berlin; Feng, Xu [KEK; Hotzel, Grit [Humboldt U. Berlin; Jansen, Karl [DESY; Petschlies, Marcus [The Cyprus Institute; Renner, Dru B. [JLAB
2013-11-01
We present results for the leading order QCD correction to the anomalous magnetic moment of the muon including the first two generations of quarks as dynamical degrees of freedom. Several light quark masses are examined in order to yield a controlled extrapolation to the physical pion mass. We analyse ensembles for three different lattice spacings and several volumes in order to investigate lattice artefacts and finite-size effects, respectively. We also provide preliminary results for this quantity for two flavours of mass-degenerate quarks at the physical value of the pion mass.
Energy Technology Data Exchange (ETDEWEB)
Okushima, Yuichiro; Chiba, Kazuhiro; Matsumoto, Morio; Maruiwa, Hirofumi; Nishizawa, Takashi; Toyama, Yoshiaki [Keio Univ., Tokyo (Japan). School of Medicine
2001-04-01
To see whether the MRI images can give a criterion for conservative therapy of the lumbar disc herniation, time changes of the images were retrospectively studied on 41 cases of spontaneous regression. They had the imaging diagnosis 3 times in average until regression with GE Signa equipment (1.5T). Images were evaluated by 2 experts. Certain cases accompanying the brightness change were seen during the process of regression. The period leading to the disappearance of melosalgia and to the regression tended to be short in cases with the brighter pulp center than disc and/or with less bright pulp verge than center. Further studies were thought necessary for clear conclusion. (K.H.)
National Research Council Canada - National Science Library
Riffle, Judy S
2006-01-01
.... Rosengart from the University of Chicago, who have designed a unique, portable, blood detoxification device with the goal of magnetically filtering undesirable components from the blood stream...
Bruna, Pablo J.; Grein, Friedrich
2008-08-01
Several properties are calculated for A 2Π u of N2+—the majority for the first time—including electric and magnetic moments, and fine/hyperfine structure (fs/hfs) parameters. The new results are compared with our previous ones for X 2Σg+ and B 2Σu+ of N2+ [P.J. Bruna, F. Grein, J. Mol. Spectrosc. 227 (2004) 67-80]. The electric quadrupole Θ and hexadecapole Φ moments, polarizability α, and hfs constants a, b, c, d, eQq 0, eQq 2 are evaluated at the density functional theory (DFT) level [B3LYP/aug-cc-pVQZ]. The fs constants (spin-orbit coupling AΠ, Λ-doubling p, q, spin-rotation γΠ), and magnetic moments ( g-factors) are obtained via 2nd-order sum-over-states expansions, using wavefunctions and matrix elements obtained with a multireference configuration interaction (MRDCI) method, and the Breit-Pauli Hamiltonian. At equilibrium, 2nd-order properties of A 2Π u are dominated by its coupling with B 2Σu+. For the A state, two independent components are reported for traceless tensor properties (multipoles Θ and Φ; hfs parameters c/d and q0/ q2) and three for traced properties (polarizability α and g-factors), i.e., one more component than for axially symmetric Σ states. The currently available experimental data on AΠ(N2+)— limited to AΠ, p, and q—are well reproduced by our theoretical results.
Magnetic intraparticle structure in ferromagnetic Pd nanoparticle
International Nuclear Information System (INIS)
Oba, Yojiro; Sato, Tetsuya; Shinohara, Takenao; Oku, Takayuki; Suzuki, Jun-ichi; Ohnuma, Masato
2009-01-01
The small-angle neutron scattering measurement of Pd nanoparticles was performed to investigate their intraparticle magnetic structures. The magnetic scattering from the magnetization of the samples was observed using the polarized neutron. The nuclear scattering indicated that the Pd nanoparticles can be regarded as spherical particles, and the magnetic scattering is explained based on the shell model that the particle is composed of magnetic core and shell. The magnetic moment of the core was larger than that of the shell. These results suggest that the spontaneous magnetization of the Pd nanoparticles mainly exists in the core region. (author)
International Nuclear Information System (INIS)
Fiori, E.
2010-12-01
Magnetic moments can provide deep insight for nuclear structure and of the wave function composition, particularly when the single particle character of the nucleus is dominating. For this reason, the magnetic moment of the first excited state of the radioactive neutron-rich 72 Zn was measured at the GANIL facility (Caen, France). The result of the experiment confirmed the trend predicted by the shell model calculations, even if the error on the measurement did not allow for a rigorous constraint of the theories. The measurement was performed using the transient field (TF) technique and the nuclei of interest were produced in a fragmentation reaction. Before this experiment, the high-velocity TF (HVTF) technique had been used only with projectile up to Z = 24. It was the first time that a magnetic moment of an heavy ion with Z > 24 was measured in the high velocity regime. To further develop the technique and to gather information about the hyperfine interaction between the polarized electrons and the nucleons, two experiments were performed at LNS (Catania, Italy). In this thesis the development of the high-velocity TF technique for the experiments on g(2 + ; 72 Zn) and field strength B TF (Kr, Ge) is presented. The analysis of the results and their interpretation is then discussed. It was demonstrated that the HVTF technique, combined with Coulomb excitation, can be used for the measurement of g-factors of very short-lived states, with lifetimes of the order of tens of ps and lower, of heavy ions (A ∼ 80) traveling with intermediate relativistic speeds, β ∼ 0.25. The standard TF technique at low velocities (a few percent of the speed of light) has been used for a long time to provide the strong magnetic field necessary for the measurement of g-factors of very short-lived states. The breakthrough of the present development is the different velocity regime of the higher mass projectile under which the experiment is carried out
DFT+DMFT study on soft moment magnetism and covalent bonding in SrRu2O6
Hariki, Atsushi; Hausoel, Andreas; Sangiovanni, Giorgio; Kuneš, Jan
2017-10-01
The dynamical mean-field theory is used to study the three-orbital model of the d3 compound SrRu2O3 both with and without explicitly including the O-p states. Depending on the size of the Hund's coupling J , at low to intermediate temperatures we find solutions corresponding to Mott or correlated covalent insulators. The latter can explain the experimentally observed absence of Curie susceptibility in the paramagnetic phase. At high temperatures, a single phase with smoothly varying properties is observed. SrRu2O3 provides an ideal system to study the competition between the local moment physics and covalent bonding, since both effects are maximized, while SO interaction is found to play a minor role.
Khmelevskyi, S; Turek, I; Mohn, P
2003-07-18
We show that the large negative magnetic contribution to the thermal expansion in disordered Fe-Pt alloys can be understood within the disordered local moment (DLM) approach. On the basis of first principles calculations we quantitatively describe the spontaneous volume magnetostriction for various Pt concentrations. It is found that the Invar effect in these alloys is entirely related to the state of thermal magnetic disorder modeled by the DLM states. We also show that the experimentally observed anomaly in the temperature dependence of the magnetization is due to a spontaneous reduction of the local magnetic moments rather than to "hidden excitations."
Teachable Moment: Google Earth Takes Us There
Williams, Ann; Davinroy, Thomas C.
2015-01-01
In the current educational climate, where clearly articulated learning objectives are required, it is clear that the spontaneous teachable moment still has its place. Authors Ann Williams and Thomas Davinroy think that instructors from almost any discipline can employ Google Earth as a tool to take advantage of teachable moments through the…
Spontaneous intracranial hypotension.
LENUS (Irish Health Repository)
Fullam, L
2012-01-31
INTRODUCTION: Spontaneous\\/primary intracranial hypotension is characterised by orthostatic headache and is associated with characteristic magnetic resonance imaging findings. CASE REPORT: We present a case report of a patient with typical symptoms and classical radiological images. DISCUSSION: Spontaneous intracranial hypotension is an under-recognised cause of headache and can be diagnosed by history of typical orthostatic headache and findings on MRI brain.
Czech Academy of Sciences Publication Activity Database
Rusz, Ján; Lidbaum, H.; Rubino, S.; Hjörvarsson, B.; Oppeneer, P.M.; Eriksson, O.; Leifer, K.
2011-01-01
Roč. 83, č. 13 (2011), "132402-1"-"132402-4" ISSN 1098-0121 Institutional research plan: CEZ:AV0Z10100521 Keywords : EMCD experiments Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.691, year: 2011
Energy Technology Data Exchange (ETDEWEB)
Watanabe, T.; Saito, N.; Takahashi, A.; Fujimaki, H.; Tosaka, M.; Sasaki, T. [Department of Neurosurgery, Gunma University School of Medicine, 3-39-22 Showa-machi, 371-8511, Maebashi, Gunma (Japan); Sato, N. [Department of Diagnostic Radiology, Gunma University School of Medicine, Maebashi, Gunma (Japan)
2003-07-01
Mastoid effusion is a poorly understood complication after craniotomy. The incidence and severity of postoperative mastoid effusion were retrospectively examined on postoperative magnetic resonance (MR) images to assess any association with craniotomy procedures, time course, and neuro-otological complications. We evaluated the early postoperative MR images (within 4 days of craniotomy) and medical records of 74 patients who underwent 77 operations for the treatment of various intracranial diseases from January 2000 to December 2001. Mastoid effusion was classified into four grades: none, partial, moderate, and severe diffuse effusion in the mastoid air cells. Thirty-three follow-up MR images from 26 patients were also reviewed. Postoperative mastoid effusion occurred ipsilateral to the craniotomy site in 62 cases and contralateral in 56 cases. Mastoid effusion was significantly more severe ipsilateral than contralateral to craniotomy with exposure of the mastoid air cells (P<0.0001). There was no significant difference in severity between the contralateral and ipsilateral sides after craniotomy without mastoid air cell opening (P=0.437). Mastoid effusion following craniotomy without exposure of mastoid air cells resolved within 3 months. However, otitis media with effusion developed in six patients with severe mastoid effusion ipsilateral to craniotomy with exposure of the mastoid air cells. Mastoid effusion frequently developed on both sides. Any grade of mastoid effusion on the ipsilateral side to craniotomy without exposure of mastoid air cells, or on the contralateral side, was asymptomatic or had a benign course, and disappeared within 3 months. (orig.)
International Nuclear Information System (INIS)
Meyer, C.A.
1987-06-01
We have measured the cross section from the bremsstrahlung process π + p → π + pγ for incident pions of energy 299 MeV. We detected the out going pion in the angular range from 55 to 95 0 in the lab, and photons were detected near 240 0 in the lab. We compare this measured cross-section to the MIT theory in order to extract a measurement of the magnetic dipole moment of the Δ ++ (1232), μ/sub Δ/. In order to compare our results with the MIT theory, we have folded the MIT theory into the acceptance of our apparatus. We find that for pion angles between 55 and 75 0 the theory gives us a dipole moment of: 2.3μ/sub p/ 0 we find that the MIT theory predicts a cross-section which is larger than our measured cross-section, and makes it difficult to extract a value of μ/sub Δ/. This over prediction is not understood, but consistent with a similar effect when the MIT theory is fit to previous data. 78 figs., 29 tabs
International Nuclear Information System (INIS)
Elhandi, S.; Taj, S.; Attaourti, Y.; Manaut, B.; Oufni, L.
2010-01-01
The effect of the electron's anomalous magnetic moment on the relativistic electronic dressing for the process of electron-hydrogen atom elastic collisions is investigated. We consider a laser field with circular polarization and various electric field strengths. The Dirac-Volkov states taking into account this anomaly are used to describe the process in the first order of perturbation theory. The correlation between the terms coming from this anomaly and the electric field strength gives rise to the strong dependence of the spinor part of the differential cross section (DCS) with respect to these terms. A detailed study has been devoted to the nonrelativistic regime as well as the moderate relativistic regime. Some aspects of this dependence as well as the dynamical behavior of the DCS in the relativistic regime have been addressed.
Blum, Thomas; Christ, Norman; Hayakawa, Masashi; Izubuchi, Taku; Jin, Luchang; Jung, Chulwoo; Lehner, Christoph
2017-01-13
We report a lattice QCD calculation of the hadronic light-by-light contribution to the muon anomalous magnetic moment at a physical pion mass. The calculation includes the connected diagrams and the leading, quark-line-disconnected diagrams. We incorporate algorithmic improvements developed in our previous work. The calculation was performed on the 48^{3}×96 ensemble generated with a physical pion mass and a 5.5 fm spatial extent by the RBC and UKQCD Collaborations using the chiral, domain wall fermion formulation. We find a_{μ}^{HLbL}=5.35(1.35)×10^{-10}, where the error is statistical only. The finite-volume and finite lattice-spacing errors could be quite large and are the subject of ongoing research. The omitted disconnected graphs, while expected to give a correction of order 10%, also need to be computed.
Smolyakov, M N
2000-01-01
This paper deals with electromagnetic radiation generated by relativistic particles in arbitrary planar magnetic field (in undulator for example). Magnetic system producing this field is assumed to be planar consisting of permanent magnets. It is shown that there is a special class of magnetic moment rotations in such system while magnetic field is varying but spontaneous radiation spectrum generated by relativistic particles remains the same. This property of electromagnetic radiation can be used in designing new undulators.
DEFF Research Database (Denmark)
Szpunar, B.; Kozarzewski, B.
1977-01-01
with a narrow d-band is considered. The magnetic moment of the alloy at zero temperature is calculated within the molecular field and Hartree-Fock approximations. Disorder is treated in the coherent potential approximation. Results are in good agreement with the experimental data obtained for the crystalline......Calculations are made of the mean magnetic moment per atom of the transition metal and the rare-earth metal in the intermetallic compounds, Gd1-x,Nix, Gd1-x Fex, Gd1-x Cox, and Y1-x Cox. A simple model of the disordered alloy consisting of spins localized on the rare-earth atoms and interacting...
Czech Academy of Sciences Publication Activity Database
Wilhelm, F.; Sanchez, J.P.; Brison, J.P.; Aoki, D.; Shick, Alexander; Rogalev, A.
2017-01-01
Roč. 95, č. 23 (2017), s. 1-10, č. článku 235147. ISSN 2469-9950 R&D Projects: GA ČR GA15-07172S Institutional support: RVO:68378271 Keywords : ferromagnetic superconductors * density functional theory Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.836, year: 2016
DEFF Research Database (Denmark)
Hastrup, Kirsten Blinkenberg
2017-01-01
as an experiment in real time, where insights gained intersubjectively gradually shape up as knowledge through analysis. This line of thought is brought to bear on a discussion of collaboration between anthropologists, archaeologists, and biologists in North West Greenland. Through actual experiences from...... the field, this article shows how knowledge generated on the edge of one’s familiar disciplinary territory may both expand and intensify the anthropological field. Collaborative moments are seen to make new anthropological insights emerge through the co-presence of several analytical perspectives...
Czech Academy of Sciences Publication Activity Database
Gorbunov, Denis; Henriques, Margarida Isabel Sousa; Andreev, Alexander V.; Eigner, Václav; Gukasov, A.; Fabrèges, X.; Skourski, Y.; Petříček, Václav; Wosnitza, J.
2016-01-01
Roč. 93, č. 2 (2016), 1-11, č. článku 024407. ISSN 1098-0121 R&D Projects: GA ČR GA16-03593S; GA ČR GA15-12653S; GA MŠk LO1603 EU Projects: European Commission(XE) CZ.2.16/3.1.00/24510 Institutional support: RVO:68378271 Keywords : rare-earth intermetallics * ferromagnetism * magnetic anisotropy * neutron diffraction Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.736, year: 2014
Saadaoui, H.; Salman, Z.; Prokscha, T.; Suter, A.; Huhtinen, H.; Paturi, P.; Morenzoni, E.
2013-11-01
We report the results of a search for spontaneous magnetism due to a time-reversal symmetry breaking phase in the superconducting state of (110)-oriented YBa2Cu3O7-δ films, expected near the surface in this geometry. Zero field and weak transverse field measurements performed using the low-energy muon spin rotation technique with muons implanted a few nm inside optimally doped YBa2Cu3O7-δ-(110) films show no appearance of spontaneous magnetic fields below the superconducting temperature down to 2.9 K. Our results give an upper limit of ˜0.02 mT for putative spontaneous internal fields.
Blum, Thomas; Christ, Norman; Hayakawa, Masashi; Izubuchi, Taku; Jin, Luchang; Jung, Chulwoo; Lehner, Christoph
2017-08-01
In our previous work, Blum et al. [Phys. Rev. Lett. 118, 022005 (2017), 10.1103/PhysRevLett.118.022005], the connected and leading disconnected hadronic light-by-light contributions to the muon anomalous magnetic moment (g -2 ) have been computed using lattice QCD ensembles corresponding to physical pion mass generated by the RBC/UKQCD Collaboration. However, the calculation is expected to suffer from a significant finite-volume error that scales like 1 /L2 where L is the spatial size of the lattice. In this paper, we demonstrate that this problem is cured by treating the muon and photons in infinite-volume, continuum QED, resulting in a weighting function that is precomputed and saved with affordable cost and sufficient accuracy. We present numerical results for the case when the quark loop is replaced by a muon loop, finding the expected exponential approach to the infinite volume limit and consistency with the known analytic result. We have implemented an improved weighting function which reduces both discretization and finite-volume effects arising from the hadronic part of the amplitude.
The nuclear magnetic moment of 208Bi and its relevance for a test of bound-state strong-field QED
Schmidt, S.; Billowes, J.; Bissell, M. L.; Blaum, K.; Garcia Ruiz, R. F.; Heylen, H.; Malbrunot-Ettenauer, S.; Neyens, G.; Nörtershäuser, W.; Plunien, G.; Sailer, S.; Shabaev, V. M.; Skripnikov, L. V.; Tupitsyn, I. I.; Volotka, A. V.; Yang, X. F.
2018-04-01
The hyperfine structure splitting in the 6p3 3/2 4S → 6p2 7 s 1/2 4P transition at 307 nm in atomic 208Bi was measured with collinear laser spectroscopy at ISOLDE, CERN. The hyperfine A and B factors of both states were determined with an order of magnitude improved accuracy. Based on these measurements, theoretical input for the hyperfine structure anomaly, and results from hyperfine measurements on hydrogen-like and lithium-like 209Bi80+,82+, the nuclear magnetic moment of 208Bi has been determined to μ (208Bi) = + 4.570 (10)μN. Using this value, the transition energy of the ground-state hyperfine splitting in hydrogen-like and lithium-like 208Bi80+,82+ and their specific difference of -67.491(5)(148) meV are predicted. This provides a means for an experimental confirmation of the cancellation of nuclear structure effects in the specific difference in order to exclude such contributions as the cause of the hyperfine puzzle, the recently reported 7-σ discrepancy between experiment and bound-state strong-field QED calculations of the specific difference in the hyperfine structure splitting of 209Bi80+,82+.
Paul Callaghan luminous moments
Callaghan, Paul
2013-01-01
Acknowledged internationally for his ground-breaking scientific research in the field of magnetic resonance, Sir Paul Callaghan was a scientist and visionary with a rare gift for promoting science to a wide audience. He was named New Zealander of the Year in 2011. His death in early 2012 robbed New Zealand of an inspirational leader. Paul Callaghan: Luminous Moments brings together some of his most significant writing. Whether he describes his childhood in Wanganui, reflects on discovering the beauty of science, sets out New Zealand's future potential or discusses the experience of fa
Energy Technology Data Exchange (ETDEWEB)
Cusmano, F.; Calabrese, G.; Bassi, S.; Branislav, S.; Bassi, P. [Parma Univ., Parma (Italy). Ist. di Scienze Radiologiche
2000-09-01
Purpose of this work is to report the Magnetic Resonance Imaging (MRI) features of acute and chronic spontaneous spondylodiscitis as well as any as well as any typical patterns which can be useful for the differential diagnosis between pyogenic and tuberculous forms. Eleven patients affected with spontaneous spondylodiscitis were selected for the study; they were 7 men and 4 women ranging in age 33-87 years (mean: 64). Patients with a superconductive magnet at 1.5, with the following sequences: sagittal PD and T2-weighted TSE, sagittal T1-weighted SE, axial PD and T2-weighted TSE for the lumbar spine, axial T2-weighted GRE for the cervical and dorsal spine and axial and sagittal T1-weighted SE after contrast agent (gadolinium DTPA) injection. MR images were reviewed by three experienced radiologists and morphological and signal intensity changes of vertebral body and disk were recorded on a standard form. In 9 patients it was possible to compare MR to CT findings. Three patients had infectious diseases in other organs and 2 were diabetics. Biopsy was performed in two cases only and demonstrated Staphylococcus aureus in one and Mycobacterium tuberculosis in the other patient. MRI, allowed the correct diagnosis to be made in all cases, demonstrating the pathological involvement of the paravertebral structures and into the spinal canal earlier and more accurately than CT. A common finding in pyogenic and tuberculous spondylodiscitis was the low signal of the subcortical bone marrow on T1-weighted sagittal images, which enhanced after Gd-DTPA administration and became intermediate or high on T2-weighted images. Moreover, the steady high signal intensity of the disk on T2-weighted images and its contrast enhancement on T1-weighted images is typical for an acute inflammatory process. Based on our personal experience an literature data, it is believed that MRI is the most sensitive technique for the diagnosis of spondylodiscitis in the acute phase, whereas it is
Energy Technology Data Exchange (ETDEWEB)
Ortega, R.; Pastor, J.; Escamilla, F.; Romero, M. I. [Hospital de Traumatologia y Reabilitacion. Granada (Spain)
1999-07-01
The postural headache syndrome associated with a decrease in the cerebrospinal fluid (CSF) pressure is generally secondary to the CSF leakage that usually occurs after diagnostic lumbar puncture. Spontaneous intracranial hypotension can not be attributed to any known cause or previous diagnostic or therapeutic intervention. The syndrome is characterized by severe headache that is relieved by lying supine. During lumbar puncture, the CSF pressure is normally low. We present two patients in whom gadolinium-enhanced magnetic resonance imaging showed widespread thickening and enhancement of the dura mater and subdural fluid collections. (Author) 13 refs.
DEFF Research Database (Denmark)
Boseggia, S.; Walker, H. C.; Vale, J.
2013-01-01
Sr2IrO4 is a prototype of the class of Mott insulators in the strong spin–orbit interaction (SOI) limit described by a Jeff = 1/2 ground state. In Sr2IrO4, the strong SOI is predicted to manifest itself in the locking of the canting of the magnetic moments to the correlated rotation by 11.8(1)° o...
Baryshevsky, V. G.
2015-01-01
We study the phenomena of spin rotation and depolarization of high-energy particles in crystals in the range of high energies that will be available at Hadron Collider (LHC) and Future Circular Collider (FCC). It is shown that these phenomena can be used to measure the anomalous magnetic moments of short-lived particles in this range of energies. We also demonstrate that the phenomenon of particle spin depolarization in crystals provides a unique possibility of measuring the anomalous magneti...
Evolution of the magnetic order in the Ho(Mn, Al) sub 2 system; neutron diffraction study
Golosovsky, I V; Markosyan, A S; Roisnel, T
2002-01-01
The neutron diffraction study of Ho(Mn sub 1 sub - sub x Al sub x) sub 2 shows the coexistence of two cubic Laves phases with different unit-cell parameters and substantially different magnetic behaviours. The first phase combines ordered ferrimagnetic and disordered antiferromagnetic components of the magnetic moments. With increasing Al content, starting from the long-range ferrimagnetic order with the induced Mn moment in HoMn sub 2 , the progressive formation of spontaneous Mn moments yields short-range order, which in turn transforms to ferromagnetic order in HoAl sub 2. The second phase with incommensurate magnetic structure is driven by the spontaneous Mn moments and exists only over limited ranges of Al content and unit-cell parameter. It has a finite correlation length and appears from a second-order transition without a magneto-volume effect.
Indian Academy of Sciences (India)
Unknown
netic moments of the particles, i.e. Zeeman energy, µH, where µ is the magnetic moment of the particle and H .... the domain magnetization of particle. Here, we have assumed a log-normal distribution function, P(D), for ... Effect of texturing field on a magnetically textured fluid magnetization for (a) (HT || H) and (b) (HT ⊥ H) ...
Energy Technology Data Exchange (ETDEWEB)
Aguilera-Granja, F [Instituto de Fisica, Universidad Autonoma de San Luis PotosI, SLP 78000 (Mexico); Vega, A [Departamento de Fisica Teorica, Atomica, y Optica, Universidad de Valladolid, E-47011 Valladolid (Spain); Gallego, L J [Departamento de Fisica de la Materia Condensada, Facultad de Fisica, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela (Spain)
2008-04-09
We report the results of density-functional calculations of the structures, binding energies and magnetic moments of the clusters Mo{sub N} (N = 2-13), Mo{sub 12}Fe, Mo{sub 12}Co and Mo{sub 12}Ni that were performed using the SIESTA method within the generalized gradient approximation for exchange and correlation. For pure Mo{sub N} clusters, we obtain collinear magnetic structures in all cases, even when the self-consistent calculations were started from non-collinear inputs. Our results for these clusters show that both linear, planar and three-dimensional clusters have a strong tendency to form dimers. In general, even-numbered clusters are more stable than their neighbouring odd-numbered clusters because they can accommodate an integer number of tightly bound dimers. As a consequence, the binding energies of pure Mo{sub N} clusters, in their lowest-energy states, exhibit an odd-even effect in all dimensionalities. Odd-even effects are less noticeable in the magnetic moments than in the binding energies. When comparing our results for pure Mo clusters with those obtained recently by other authors, we observe similarities in some cases, but striking differences in others. In particular, the odd-even effect in three-dimensional Mo clusters was not observed before, and our results for some clusters (e.g. for planar Mo{sub 3} and Mo{sub 7} and for three-dimensional Mo{sub 7} and Mo{sub 13}) differ from those reported by other authors. For Mo{sub 12}Fe and Mo{sub 12}Ni, we obtain that the icosahedral configuration with the impurity atom at the cluster surface is more stable than the configuration with the impurity at the central site, while the opposite occurs in the case of Mo{sub 12}Co. In Mo{sub 12}Co and Mo{sub 12}Ni, the impurities exhibit a weak magnetic moment parallely coupled to the total magnetic moment of the Mo atoms, whereas in Mo{sub 12}Fe the impurity shows a high moment with antiparallel coupling.
Final Report for the project “The Electron Diffusion Region in 3D Spontaneous Magnetic Reconnection”
Energy Technology Data Exchange (ETDEWEB)
Egedal-Pedersen, Jan [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Univ. of Wisconsin, Madison, WI (United States). Dept. of Physics
2016-01-19
The DOE award, Grant ER55099, supported in part three graduate students (now Drs. A. Le, O. Ohia and A Vrublenski) and material expenses. The grant enabled these students to operate a basic plasma physics experiment on magnetic reconnection at the MIT Plasma Science and Fusion Center. The experimental investigations utilized the Versatile Toroidal Facility (VTF) in various magnetic geometries. In addition, based in part on the experimental results, new theoretical models were developed for the reconnection process.
Assembling Transgender Moments
Greteman, Adam J.
2017-01-01
In this article, the author seeks to assemble moments--scholarly, popular, and aesthetic--in order to explore the possibilities that emerge as moments collect in education's encounters with the needs, struggles, and possibilities of transgender lives and practices. Assembling moments, the author argues, illustrates the value of "moments"…
An Evolutionary Game Theory Model of Spontaneous Brain Functioning.
Madeo, Dario; Talarico, Agostino; Pascual-Leone, Alvaro; Mocenni, Chiara; Santarnecchi, Emiliano
2017-11-22
Our brain is a complex system of interconnected regions spontaneously organized into distinct networks. The integration of information between and within these networks is a continuous process that can be observed even when the brain is at rest, i.e. not engaged in any particular task. Moreover, such spontaneous dynamics show predictive value over individual cognitive profile and constitute a potential marker in neurological and psychiatric conditions, making its understanding of fundamental importance in modern neuroscience. Here we present a theoretical and mathematical model based on an extension of evolutionary game theory on networks (EGN), able to capture brain's interregional dynamics by balancing emulative and non-emulative attitudes among brain regions. This results in the net behavior of nodes composing resting-state networks identified using functional magnetic resonance imaging (fMRI), determining their moment-to-moment level of activation and inhibition as expressed by positive and negative shifts in BOLD fMRI signal. By spontaneously generating low-frequency oscillatory behaviors, the EGN model is able to mimic functional connectivity dynamics, approximate fMRI time series on the basis of initial subset of available data, as well as simulate the impact of network lesions and provide evidence of compensation mechanisms across networks. Results suggest evolutionary game theory on networks as a new potential framework for the understanding of human brain network dynamics.
International Nuclear Information System (INIS)
Kingston, A.E.; Norrington, P.H.; Boone, A.W.
2002-01-01
The spontaneous decay rates for the electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1) and magnetic quadrupole (M2) transitions between all of the 1s 2 , 1s2 l and 1s3 l states have been obtained for helium-like calcium and sulfur ions. To assess the accuracy of the calculations, the transition probabilities were calculated using two sets of configuration interaction wavefunctions. One set of wavefunctions was generated using the fully relativistic GRASP code and the other was obtained using CIV3, in which relativistic effects are introduced using the Breit-Pauli approximation. The transition rates, A values, oscillator strengths and line strengths from our two calculations are found to be similar and to compare very well with other recent results for Δn=1 or 2 transitions. For Δn=0 transitions the agreement is much less good; this is mainly due to differences in the calculated excitation energies. (author)
Measurement of excited state static moments
International Nuclear Information System (INIS)
Sergolle, Henri
Electric quadrupole and magnetic dipole moments are defined from a classical description of the nucleus and a quantum expression is given for the operators. The principal characteristics of the moment interaction with an outer electric or magnetic field are recalled. The study of the perturbed angular distributions of nuclear reaction products allows half-lives of high spin isomer states to be measured (from a few ps to several hours). The decay gamma rays present, under certain conditions, a strong anisotropy; in principle only one detector is sufficient to observe the angular distribution; coincidences are unnecessary and a high counting rate becomes possible. The measurement of the Coulomb excitation probabilities give the electric (dynamic and static) moments and indirectly quadrupolar moments; two techniques are used: the analysis of elastically and inelastically scattered particles and measurement of the deexcitation γ rays in coincidence with the scattered ions. Quadrupole moments can be measured from the precession of the angular distribution [fr
Directory of Open Access Journals (Sweden)
Davari R
1996-07-01
Full Text Available A case with bilateral spontaneous pneumothorax was presented. Etiology, mechanism, and treatment were discussed on the review of literature. Spontaneous Pneumothorax is a clinical entity resulting from a sudden non traumatic rupture of the lung. Biach reported in 1880 that 78% of 916 patients with spontaneous pneumothorax had tuberculosis. Kjergaard emphasized 1932 the primary importance of subpleural bleb disease. Currently the clinical spectrum of spontaneous pneumothorax seems to have entered a third era with the recognition of the interstitial lung disease and AIDS as a significant etiology. Standard treatment is including: observation, thoracocentesis, tube thoracostomy. Chemical pleurodesis, bullectomy or wedge resection of lung with pleural abrasion and occasionally pleurectomy. Little information has been reported regarding the efficacy of such treatment in spontaneous pneumothorax secondary to non bleb disease
Magnetism of elementary particles
Vonsovsky, S V
1975-01-01
Spin magnetic moment of the electron ; magnetism of the atomic electron shell ; magnetism of nucleons (protons and neutrons) and atomic nuclei ; anomalous magnetic moments of elementary particles ; the magnetic monopole ; non-linear quantum-electrodynamic effects in a magnetic field.
Solvents level dipole moments.
Liang, Wenkel; Li, Xiaosong; Dalton, Larry R; Robinson, Bruce H; Eichinger, Bruce E
2011-11-03
The dipole moments of highly polar molecules measured in solution are usually smaller than the molecular dipole moments that are calculated with reaction field methods, whereas vacuum values are routinely calculated in good agreement with available vapor phase data. Whether from Onsager's theory (or variations thereof) or from quantum mechanical methods, the calculated molecular dipoles in solution are found to be larger than those measured. The reason, of course, is that experiments measure the net dipole moment of solute together with the polarized (perturbed) solvent "cloud" surrounding it. Here we show that the reaction field charges that are generated in the quantum mechanical self-consistent reaction field (SCRF) method give a good estimate of the net dipole moment of the solute molecule together with the moment arising from the reaction field charges. This net dipole is a better description of experimental data than the vacuum dipole moment and certainly better than the bare dipole moment of the polarized solute molecule.
Takahashi, Kazunori; Suzuki, Tatsuya; Ando, Akira
2014-02-01
Diameter of a permanent-magnets-expanded, radiofrequency (rf) plasma source is enlarged up to ∼13 cm for an application to a space propulsion device and tested with being attached to a diffusion chamber. The source is operated at 13.56 MHz 300 W rf power in low-pressure (40 mPa) argon. Measurement of ion energy distribution functions downstream of the source exit shows generation of a supersonic ion beam of about 20 eV. The detailed radial measurements demonstrate that the diameter and energy of the ion beam corresponds to the source tube diameter and the potential difference between the source and downstream plasmas, and that the radial profile of the beam flux is similar to the plasma density profile in the source cavity.
High field magnetization of (Rx Y1-x)Fe2 compounds
International Nuclear Information System (INIS)
Guimaraes, A.P.; Alves, K.M.B.
1991-01-01
The magnetization of the pseudo-binary intermetallic compounds (D Y x Y 1-x )Fe 2 and (Er x Y 1-x )Fe 2 was studied in high magnetic fields (up to 20 T). The saturation magnetization shows a minimum as a function of concentration, due to the anti parallel coupling of the R and Fe moments. From the magnetization curve in the high field region we derived the spontaneous magnetization and high field susceptibility, as a function of concentration. The susceptibilities, coercive fields and the anisotropy terms show maxima in the 20 - 40% concentration range. (author)
Directory of Open Access Journals (Sweden)
Habs Maximilian
2011-11-01
Full Text Available Abstract Background Previously proposed classifications for carotid plaque and cerebral parenchymal hemorrhages are used to estimate the age of hematoma according to its signal intensities on T1w and T2w MR images. Using these classifications, we systematically investigated the value of cardiovascular magnetic resonance (CMR in determining the age of vessel wall hematoma (VWH in patients with spontaneous cervical artery dissection (sCAD. Methods 35 consecutive patients (mean age 43.6 ± 9.8 years with sCAD received a cervical multi-sequence 3T CMR with fat-saturated black-blood T1w-, T2w- and TOF images. Age of sCAD was defined as time between onset of symptoms (stroke, TIA or Horner's syndrome and the CMR scan. VWH were categorized into hyperacute, acute, early subacute, late subacute and chronic based on their signal intensities on T1w- and T2w images. Results The mean age of sCAD was 2.0, 5.8, 15.7 and 58.7 days in patients with acute, early subacute, late subacute and chronic VWH as classified by CMR (p Conclusions Signal intensities of VWH in sCAD vary over time and multi-sequence CMR can help to determine the age of an arterial dissection. Furthermore, findings of this study suggest that the time course of carotid hematomas differs from that of cerebral hematomas.
de Francisco, Olga Nicolas; Feeney, Daniel; Armién, Anibal G; Wuenschmann, Arno; Redig, Patrick T
2016-04-01
Six bald eagles with severe, acute lead poisoning based on blood lead values were analyzed by Magnetic Resonance Imaging (MRI) of the brain and histopathology. The aims of the study were to use MRI to locate brain lesions and correlate the changes in MRI signal with the histological character of the lesions at necropsy. All of the bald eagles presented with neurologic and non-neurologic signs suggestive of severe lead poisoning and had blood lead levels in excess of 1.0 ppm. Areas of change in image intensity in the brainstem, midbrain and cerebellum were detected in the MRI scans. Histopathology confirmed the presence of all suspected lesions. The character of the lesions suggested vascular damage as the primary insult. MRI was useful for detecting lesions and defining their three-dimensional distribution and extent. Future studies are needed to evaluate the utility of MRI for detection of lesions in less severely lead poisoned eagles and determining prognosis for treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.
2006-01-01
One of the first events reconstructed in the Muon Drift Tubes, the Hadron Calorimeter and elements of the Silicon Tracker (TK) at 3 Tesla. The atmosphere in the CMS control rooms was electric. Everbody was at the helm for the first full-scale testing of the experiment. This was a crunch moment for the entire collaboration. On Tuesday, 22 August the magnet attained almost its nominal power of 4 Tesla! At the same moment, in a tiny improvised control room, the physicists were keyed up to test the entire detector system for the first time. The first cosmic ray tracks appeared on their screens in the week of 15 August. The tests are set to continue for several weeks more until the first CMS components are lowered into their final positions in the cavern.
Razee, S. S.; Staunton, J. B.; Szunyogh, L.; Györffy, B. L.
2002-09-01
We describe a mean-field theory of magnetic fluctuations in layered metallic materials at finite temperatures. It has a first-principles electronic structure basis and uses the spin-polarized screened Korringa-Kohn-Rostoker method and the coherent-potential approximation to describe the effects of the fluctuating ``local moments'' upon the electronic structure. At no stage is there a fitting to an effective classical Heisenberg model. From this disordered local moment picture we find the layer dependent paramagnetic spin susceptibility of films and multilayers above the Curie temperature Tc which describes how the type of magnetic correlations varies layer by layer. We study thin films of Fe and Co (1-8 layers) on and embedded in nonmagnetic substrates, specifically bcc-Fe/W(100), fcc-Fe/Cu(100), and fcc-Co/Cu(100). In uncapped Fe/W(100) we find intralayer ferromagnetic correlations in all thicknesses of the iron film except in the layer nearest the W substrate in agreement with experiment. The interlayer couplings are also ferromagnetic and short ranged. There are also ferromagnetic intralayer and interlayer couplings throughout the Co films in fcc-Co/Cu(100). In the Fe/Cu(100) system the top two layers are coupled ferromagnetically and the rest antiferromagnetically. Cu capping has a profound effect upon the magnetic coupling in both Fe/Cu(100) and Co/Cu(100) with Tc showing an oscillating behavior as a function of the cap layer thickness. In contrast there is no dramatic effect when Fe films are embedded in W(100).
Edelman, Benjamin; Geradin, Damien
Platform businesses such as Airbnb and Uber have risen to success partly by sidestepping laws and regulations that encumber their traditional competitors. Such rule flouting is what the authors call “spontaneous private deregulation,” and it’s happening in a growing number of industries. The authors
New vision of magnetic tunnelling
Energy Technology Data Exchange (ETDEWEB)
Friedman, Jonathan R. [Amherst College, Amhurst, MA (United States)
2002-01-01
Recent experiments support the idea that crystal defects may be responsible for the quantum tunnelling of magnetic moments in molecular magnets at low temperatures. The magnetic moment of a typical bar magnet will never spontaneously reverse direction. However, thermal fluctuations can flip the moment of a magnetic particle just a few nanometres across. The particle can be cooled to nearly absolute zero to suppress this process, but the moment may still find a way to reverse via quantum tunnelling. Quantum tunnelling of magnetization has been the subject of decades of research. Until a few years ago, however, there had only been circumstantial evidence for the phenomenon. This is because most systems of small magnetic particles are hard to characterize - the particles have a variety of shapes, sizes and other properties, making it difficult to compare data with theory. Some real progress was made a few years ago through research into high-spin single-molecule magnets. With dimensions of about a nanometre, these magnets are usually composed of a magnetic core that is surrounded by organic complexes. When they crystallize into a regular lattice, the organic ions keep neighbouring magnets well separated so that they interact only weakly. Ideally all the molecules are identical because they have been built chemically, which means that they can be characterized precisely and that any data can be analysed quantitatively. The most studied of these molecules is manganese-12 acetate (Mn{sub 12}). Within each molecule, the spins of the eight Mn{sup 3+} ions (each with S=2) are antiparallel to the spins of the four Mn{sup 4+} ions (each with S=3/2), giving Mn{sub 12} a total spin of S=10. Or, to put it another way, the magnetic moment of Mn{sub 12} is 20 times larger than that of the electron. Now Eugene Chudnovsky of Lehman College in New York and Dmitry Garanin of the University of Mainz in Germany have suggested a new mechanism for producing tunnelling in Mn{sub 12
Electromagnetic moments of 22F
Mihara, M.; Matsuta, K.; Komurasaki, J.; Hirano, H.; Nishimura, D.; Momota, S.; Ohtsubo, T.; Izumikawa, T.; Shimbara, Y.; Kubo, T.; Kameda, D.; Zhou, Dongmei; Zheng, Yongnan; Yuan, Daqing; Zhu, Shengyun; Kitagawa, A.; Kanazawa, M.; Torikoshi, M.; Sato, S.; Nagatomo, T.; Matsumiya, R.; Ishikawa, D.; Fukuda, M.; Minamisono, T.; Nojiri, Y.; Alonso, J. R.; Crebs, G. F.; Symons, T. J. M.
2010-03-01
The magnetic dipole (μ) and electric quadrupole (Q) moments of short-lived nucleus 22F (Iπ=4+, T=4.2s) have been measured for the first time by means of the β-NMR technique. A spin polarized 22F beam was produced through the charge exchange reaction of 22Ne and was implanted into single crysltals of NaF and MgF2 for μ and Q measurements, respectively. As a result, |μ(F22)|=(2.69443±0.00039)μ and |Q(F22)|=(3±2)mb was obtained. These values are well reproduced by the shell model calculations.
International Nuclear Information System (INIS)
Michael Ramsey-Musolf; Wick Haxton; Ching-Pang Liu
2002-01-01
Nuclear anapole moments are parity-odd, time-reversal-even E1 moments of the electromagnetic current operator. Although the existence of this moment was recognized theoretically soon after the discovery of parity nonconservation (PNC), its experimental isolation was achieved only recently, when a new level of precision was reached in a measurement of the hyperfine dependence of atomic PNC in 133Cs. An important anapole moment bound in 205Tl also exists. In this paper, we present the details of the first calculation of these anapole moments in the framework commonly used in other studies of hadronic PNC, a meson exchange potential that includes long-range pion exchange and enough degrees of freedom to describe the five independent S-P amplitudes induced by short-range interactions. The resulting contributions of pi-, rho-, and omega-exchange to the single-nucleon anapole moment, to parity admixtures in the nuclear ground state, and to PNC exchange currents are evaluated, using configuration-mixed shell-model wave functions. The experimental anapole moment constraints on the PNC meson-nucleon coupling constants are derived and compared with those from other tests of the hadronic weak interaction. While the bounds obtained from the anapole moment results are consistent with the broad ''reasonable ranges'' defined by theory, they are not in good agreement with the constraints from the other experiments. We explore possible explanations for the discrepancy and comment on the potential importance of new experiments
Energy Technology Data Exchange (ETDEWEB)
Michael Ramsey-Musolf; Wick Haxton; Ching-Pang Liu
2002-03-29
Nuclear anapole moments are parity-odd, time-reversal-even E1 moments of the electromagnetic current operator. Although the existence of this moment was recognized theoretically soon after the discovery of parity nonconservation (PNC), its experimental isolation was achieved only recently, when a new level of precision was reached in a measurement of the hyperfine dependence of atomic PNC in 133Cs. An important anapole moment bound in 205Tl also exists. In this paper, we present the details of the first calculation of these anapole moments in the framework commonly used in other studies of hadronic PNC, a meson exchange potential that includes long-range pion exchange and enough degrees of freedom to describe the five independent S-P amplitudes induced by short-range interactions. The resulting contributions of pi-, rho-, and omega-exchange to the single-nucleon anapole moment, to parity admixtures in the nuclear ground state, and to PNC exchange currents are evaluated, using configuration-mixed shell-model wave functions. The experimental anapole moment constraints on the PNC meson-nucleon coupling constants are derived and compared with those from other tests of the hadronic weak interaction. While the bounds obtained from the anapole moment results are consistent with the broad ''reasonable ranges'' defined by theory, they are not in good agreement with the constraints from the other experiments. We explore possible explanations for the discrepancy and comment on the potential importance of new experiments.
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)
Moment graphs and representations
DEFF Research Database (Denmark)
Jantzen, Jens Carsten
2012-01-01
Moment graphs and sheaves on moment graphs are basically combinatorial objects that have be used to describe equivariant intersectiion cohomology. In these lectures we are going to show that they can be used to provide a direct link from this cohomology to the representation theory of simple Lie...
Schmüdgen, Konrad
2017-01-01
This advanced textbook provides a comprehensive and unified account of the moment problem. It covers the classical one-dimensional theory and its multidimensional generalization, including modern methods and recent developments. In both the one-dimensional and multidimensional cases, the full and truncated moment problems are carefully treated separately. Fundamental concepts, results and methods are developed in detail and accompanied by numerous examples and exercises. Particular attention is given to powerful modern techniques such as real algebraic geometry and Hilbert space operators. A wide range of important aspects are covered, including the Nevanlinna parametrization for indeterminate moment problems, canonical and principal measures for truncated moment problems, the interplay between Positivstellensätze and moment problems on semi-algebraic sets, the fibre theorem, multidimensional determinacy theory, operator-theoretic approaches, and the existence theory and important special topics of multidime...
DFT+DMFT study on soft moment magnetism and covalent bonding in SrRu.sub.2./sub.O.sub.6./sub.
Czech Academy of Sciences Publication Activity Database
Hariki, A.; Hausoel, A.; Sangiovanni, G.; Kuneš, Jan
2017-01-01
Roč. 96, č. 15 (2017), s. 1-8, č. článku 155135. ISSN 2469-9950 EU Projects: European Commission(XE) 646807 - EXMAG Institutional support: RVO:68378271 Keywords : covalent insulator * dynamical mean-field theory Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.836, year: 2016
2013-01-01
Elastic and anelastic properties of a member of the BiFeO3–CaFeO2.5 perovskite solid solution (BCFO), which is known to have multiple instabilities, have been investigated by resonant ultrasound spectroscopy. This phase, with 64% Bi and 36% Ca on the A site, is antiferromagnetic (TN ∼650 K) and has an ordered arrangement of oxygen vacancies with tetragonal lattice geometry. The inverse mechanical quality factor, Q–1, has a maximum near 100 K, correlating closely with a peak in dielectric loss, reported previously, consistent with a loss mechanism that involves the movement of oxygen vacancies accompanied by local lattice distortion. At higher temperature, there is a further acoustic loss peak that is correlated with complex impedance anomalies. There is no clear relationship to the magnetic transition, and the observations are interpreted as relating to ionic conductivity. A small stiffening, scaling with the square of the magnetic order parameter below TN, indicates that the main coupling with strain is biquadratic, confirming that conventional coupling of magnetic order with symmetry-breaking shear strains is weak in BCFO. Data from the literature for BCFO indicates that local strain fields are likely to be responsible for suppressing the spin cycloid present in BiFeO3. PMID:24489435
International Nuclear Information System (INIS)
Ning Yang
2004-01-01
Thermal expansion anomalies of R 2 Fe 14 B and R 2 Fe 17 C x (x = 0,2) (R Y, Nd, Gd, Tb, Er) stoichiometric compounds are studied with high-energy synchrotron X-ray powder diffraction using Debye-Schemer geometry in temperature range 10K to 1000K. Large spontaneous magnetostriction up to their Curie temperatures (T c ) is observed. The a-axes show relatively larger invar effects than c-axes in the R 2 Fe 14 B compounds whereas the R 2 Fe 17 C x show the contrary anisotropies. The iron sub-lattice is shown to dominate the spontaneous magnetostriction of the compounds. The contribution of the rare earth sublattice is roughly proportional to the spin magnetic moment of the rare earth in the R 2 Fe 14 B compounds but in R 2 Fe 17 C x , the rare earth sub-lattice contribution appears more likely to be dominated by the local bonding. The calculation of spontaneous magnetostrain of bonds shows that the bonds associated with Fe(j2) sites in R 2 Fe 14 B and the dumbbell sites in R 2 Fe 17 C x have larger values, which is strongly related to their largest magnetic moment and Wigner-Seitz atomic cell volume. The roles of the carbon atoms in increasing the Curie temperatures of the R 2 Fe 17 compounds are attributed to the increased separation of Fe hexagons. The R 2 Fe 17 and R 2 Fe 14 B phases with magnetic rare earth ions also show anisotropies of thermal expansion above T c . For R 2 Fe 17 and R 2 Fe 14 B the a a /a c > 1 whereas the anisotropy is reversed with the interstitial carbon in R 2 Fe 17 . The average bond magnetostrain is shown to be a possible predictor of the magnetic moment of Fe sites in the compounds. Both of the theoretical and phenomenological models on spontaneous magnetostriction are discussed and a Landau model on the spontaneous magnetostriction is proposed
Spontaneous Intracranial Hypotension without Orthostatic Headache
Directory of Open Access Journals (Sweden)
Tülay Kansu
2009-03-01
Full Text Available We report 2 cases of spontaneous intracranial hypotension that presented with unilateral abducens nerve palsy, without orthostatic headache. While sixth nerve palsies improved without any intervention, subdural hematoma was detected with magnetic resonance imaging. We conclude that headache may be absent in spontaneous intracranial hypotension and spontaneous improvement of sixth nerve palsy can occur, even after the development of a subdural hematoma
International Nuclear Information System (INIS)
Krivoruchenko, M.I.
1985-01-01
In chiral bag model an expression is obtained for the quark wave functions with account of color and pion interaction of quarks. The quadrupole moments of nonstrange hadrons are calculated. Quadrupole moment of nucleon isobar is found to be Q(Δ)=-6.3x10 -28 esub(Δ)(cm)sup(2). Fredictions of the chiral bag model are in strong disagreement with the non-relativistic quark model
Energy Technology Data Exchange (ETDEWEB)
Wang, Biao [Southern Methodist U.
2017-01-01
We use the NOvA near detector and the NuMI beam at Fermilab to study the neutrino- electron elastic scattering and the muon neutrino magnetic process beyond the Standard Model physics. The particle identications of neutrino on electron elastic scattering are trained by using the multi-layer neural networks. This thesis provides a general discussion of this technique and shows a good agreement between data and MC for the neutrino-electron elastic weak scattering. So that beneting from the precise cross-section of this channel, we are able to tune the neutrino beam ux simulation in the future. Giving the exposure of 3:62 1020 POT in the NOvA near detector, we report 1:58 10
Urdampilleta, M.; Klyatskaya, S.; Ruben, M.; Wernsdorfer, W.
2013-05-01
A multiterminal device based on a carbon nanotube quantum dot was used at very low temperature to probe a single electronic and nuclear spin embedded in a bis-(phthalocyaninato) terbium (III) complex (TbPc2). A spin-valve signature with large conductance jumps was found when two molecules were strongly coupled to the nanotube. The application of a transverse field separated the magnetic signal of both molecules and enabled single-shot read-out of the terbium nuclear spin. The Landau-Zener (LZ) quantum tunneling probability was studied as a function of field sweep rate, establishing a good agreement with the LZ equation and yielding the tunnel splitting Δ. It was found that Δ increased linearly as a function of the transverse field. These studies are an essential prerequisite for the coherent manipulation of a single nuclear spin in TbPc2.
Evolution of magnetism in U(Ni 1 - xPdx) Si single crystals
Honda, F.; Andreev, A. V.; Sechovský, V.; Homma, Y.; Shiokawa, Y.
2002-12-01
Single crystals of U(Ni{1-x}Pd{x}){2}Si{2} with x = 0.05, 0.09 and 0.135 have been grown. Magnetization and electrical resistivity measurements were performed in a wide range of temperatures and magnetic fields in order to study stability of magnetic phases in the solid solutions between UNi{2}Si{2} and UPd{2}Si{2} with a special emphasis on the type of ground state. In UPd{2}Si{2} the simple AFI-type antiferromagnetic structure of U moments is observed at low temperatures. UNi{2}Si{2} adopts the uncompensated AF structure (UAF) with the ++- stacking of U moments along the c-axis and consequently this compound exhibits a spontaneous magnetization corresponding to 1/3 of the U moment. The substitution of Pd for Ni leads to a rapid decay of the spontaneous magnetization. The evolution of magnetization and electrical resistivity behavior with Pd doping is tentatively attributed to the coexistence of the AF-I and UAF phases in the ground state of U(Ni{0.91}Pd{0.09}){2}Si{2} and U(Ni{0.865}Pd{0.135}){2}Si{2}. In this scenario, the volume fraction of the AF-I phase rapidly grows with Pd doping on account of the UAF. At lowest temperatures an irreversible transition to the UAF phase is observed when a sufficiently high magnetic field is applied along the c-axis.
Magnetic properties of the Ce2Fe17-x Mn x helical magnets up to high magnetic fields
International Nuclear Information System (INIS)
Kuchin, A.G.; Mushnikov, N.V.; Bartashevich, M.I.; Prokhnenko, O.; Khrabrov, V.I.; Lapina, T.P.
2007-01-01
Magnetic properties of the Ce 2 Fe 17- x Mn x , x=0-2, alloys in magnetic fields up to 40 T are reported. The compounds with x=0.5-1 are helical antiferromagnets and those with 1 B that couple antiparallelly to the Fe moments. Easy-plane magnetic anisotropy in the Ce 2 Fe 17- x Mn x compounds weakens upon substitution of Mn for Fe. The absolute value of the first anisotropy constant in the Ce 2 Fe 17- x Mn x helical ferromagnets decreases slower with increasing temperature than that calculated from the third power of the spontaneous magnetization. Noticeable magnetic hysteresis in the Ce 2 Fe 17- x Mn x , x=0.5-2, helical magnets over the whole range of magnetic fields reflects mainly irreversible deformation of the helical magnetic structure during the magnetization of the compounds. A contribution from short-range order (SRO) magnetic clusters to the magnetic hysteresis of the helical magnets has been also estimated
Nuclear moments of nuclei near sphericity
International Nuclear Information System (INIS)
El Hajjaji, O.
1987-05-01
Magnetic and electric hyperfine interactions are studied by means of low temperature nuclear orientation. The magnetic moment of the 149 Gd isotope and that of 151 Gd are determined. The values follow the same trend as literature values of neighbouring nuclei. The calculated moments of the 7/2 - states using the Mottelson-Nilsson model without configuration mixing are nearly independent of deformation. Thus we assign the decrease of the magnetic moment versus neutron number to many particle coupling in the f shell. The Moessbauer effect detection of nuclear orientation is discussed. Two series of experiences are performed with different finalities. In the first one we determined the electric quadrupole moments of 125m Te and 129 Te. The quadrupole moments confirm the nearly spherical shape of these nuclei. In the second series we describe the Moessbauer effect of the radiation emitted by the daigleter nucleus of 125 I, implanted in two semiconductor matrices, locally oriented at low temperature by the electric field gradient of impurity-vacancy coupling. Despite the difficulty of the cooling down of Te nuclei to lattice temperature, we have shown the existence of the electric field gradient of implanted I into Si and α-Sn and determined their signs. The level mixing resonance is applied on oriented nuclei technique to determine the weak prolate deformation of silver nuclei. Studying the Δm = 3 resonance of 107 Ag m , we etablished the quadrupole moment of this state, which is in good agreement with the theoretical estimations of Moeller and Nix [fr
Energy Technology Data Exchange (ETDEWEB)
Matea, I
2003-12-01
The evolution of nuclear structure in nuclei far from the {beta} stability line is one of the 'hot topics' in modern experimental and theoretical nuclear physics. The present thesis is devoted to the study of structure of neutron-rich nuclei around N=40. The evolution of the neutron g9/2 orbital with increasing number of neutrons is one of the key points defining the structure of these nuclei at low excitation energy. We used for this investigation as experimental tools the magnetic dipole moments measurements and the {beta} decay spectroscopy. For the measurement of the gyromagnetic factor of the 9/2{sup +} isomeric state in Fe{sup 61} we have applied the TDPAD method. This method (like most of measurements of nuclear moments) requires an oriented ensemble of nuclei. The orientation of Fe{sup 61m} was achieved via the fragmentation of Ni{sup 64} at 55 MeV/u and the selection of the fragment momentum with the LISE spectrometer at GANIL. The experimental device was specially conceived to preserve the alignment up to the implantation point. The measured value of the g factor was compared with large-scale shell model and Hartree-Fock-Bogoliubov model predictions. The nuclei studied via {beta} decay were produced by the fragmentation of Kr{sup 86} at 58 MeV/u. For the selection of reaction products we used for the first time the LISE2000 spectrometer and for the detection of {gamma} rays four EXOGAM clover detectors. We measured 5 new lifetimes and 4 lifetimes with a higher precision. From the prompt {beta}{gamma} coincidences we identified new states in the daughter nuclei, as it is the case of the first 2{sup +} excited states in Fe{sup 68} and Ni{sup 72}. The results were compared with the predictions of the large-scale shell model. Other transitions were observed for the first time in {beta}{gamma} decay of Ti{sup 60}, Fe{sup 70} and Co{sup 71,73}. (author)
Determination of nuclear moments in experiments on charged particle beams
International Nuclear Information System (INIS)
Hrynkiewicz, A.Z.
Nuclear magnetic moment measurements by in-beam perturbed angular correlation method are discussed, with special emphasis on the use of transient fields. Measurements on states in several sd and dsup(5/2) nuclei are reported [fr
Spin and orbital moments in actinide compounds
DEFF Research Database (Denmark)
Lebech, B.; Wulff, M.; Lander, G.H.
1991-01-01
experiments designed to determine the magnetic moments at the actinide and transition-metal sublattice sites in compounds such as UFe2, NpCo2, and PuFe2 and to separate the spin and orbital components at the actinide sites. The results show, indeed, that the ratio of the orbital to spin moment is reduced......The extended spatial distribution of both the transition-metal 3d electrons and the actinide 5f electrons results in a strong interaction between these electron states when the relevant elements are alloyed. A particular interesting feature of this hybridization, which is predicted by single...
Energy Technology Data Exchange (ETDEWEB)
Hanks, T.C.; Kanamori, H.
1979-05-10
The nearly conincident forms of the relations between seismic moment M/sub o/ and the magnitudes M/sub L/, M/sub s/, and M/sub w/ imply a moment magnitude scale M=2/3 log M/sub o/-10.7 which is uniformly valid for 3< or approx. =M/sub L/< or approx. = 7, 5 < or approx. =M/sub s/< or approx. =7 1/2 and M/sub w/> or approx. = 7 1/2.
DEFF Research Database (Denmark)
Madsen, T. B.; Swann, A.
2012-01-01
and third Lie algebra Betti numbers are zero. We show that these form a special class of solvable Lie groups and provide a structural characterisation. We provide many examples of multi-moment maps for different geometries and use them to describe manifolds with holonomy contained in G(2) preserved by a two...
Higgins, Chris
2014-01-01
In "The Humanist Moment," Chris Higgins sets out to recover a tenable, living humanism, rejecting both the version vilified by the anti-humanists and the one sentimentalized by the reactionary nostalgists. Rescuing humanism from such polemics is only the first step, as we find at least nine rival, contemporary definitions of humanism.…
Dipole moment dark matter at the LHC
Energy Technology Data Exchange (ETDEWEB)
Barger, Vernon [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Keung, Wai-Yee [Department of Physics, University of Illinois at Chicago, IL 60607 (United States); Marfatia, Danny, E-mail: marfatia@ku.edu [Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045 (United States); Tseng, Po-Yan [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Department of Physics, National Tsing Hua University, Hsinchu 300, Taiwan (China)
2012-10-22
Monojet and monophoton final states with large missing transverse energy (E/{sub T}) are important for dark matter (DM) searches at colliders. We present analytic expressions for the differential cross sections for the parton-level processes, qq{sup Macron }(qg){yields}g(q){chi}{chi}{sup Macron} and qq{sup Macron }{yields}{gamma}{chi}{chi}{sup Macron }, for a neutral DM particle with a magnetic dipole moment (MDM) or an electric dipole moment (EDM). We collectively call such DM candidates dipole moment dark matter (DMDM). We also provide monojet cross sections for scalar, vector and axial-vector interactions. We then use ATLAS/CMS monojet+E/{sub T} data and CMS monophoton+E/{sub T} data to constrain DMDM. We find that 7 TeV LHC bounds on the MDM DM-proton scattering cross section are about six orders of magnitude weaker than on the conventional spin-independent cross section.
International Nuclear Information System (INIS)
Lagarec, K.; Rancourt, D.G.; Bose, S.K.; Sanyal, B.; Dunlap, R.A.
2001-01-01
We report the first conclusive observation of a high-moment (HM)/low-moment (LM) transition occurring in face centered cubic Fe-Ni alloys. 57 Fe Moessbauer isomer shifts give local electronic densities that exhibit a large discontinuity of ∼0.4 el./a 0 3 at the transition that spans the concentration range ∼60-80 at% Fe, in agreement with ab initio predictions. Our electronic structure calculations give an isomer shift discontinuity at a comparable composition and of the same magnitude as the observed one. This identification of the HM/LM transition in Fe-Ni allows an interpretation of the compositional dependence of the lattice parameter (at room temperature or extrapolated to T=0 K) in which it is seen that the Invar effect is an expansion, relative to normal HM non-magnetovolume active behavior, not a contraction as is required in all two-γ-state-like interpretations. Indeed, the Invar effect and the HM/LM transition are seen as two distinct and competing phenomena that dominate at different compositions and that arise from different features of the electronic structure: a large inter-atomic separation dependence of the magnetic exchange interaction between large local moments versus instability of the local moment magnitude, respectively. In the Fe-rich alloys including Invar (Fe 65 Ni 35 ), we observe temperature-induced changes in electronic density that follow the spontaneous magnetization curves and that are both consistent with the associated loss of local moment orientation order and inconsistent with a significant loss of local moment magnitude. This establishes that Invar is predominantly a HM phase at all temperatures where an Invar effect occurs. In the most Fe-rich alloys that have LM ground states (including γ-Fe), we find that thermal stabilization of the HM phase occurs at high temperatures (i.e., increase of local moment magnitude with increasing temperature), along a continuum of homogeneous phases between the LM and HM extremes, in a
Electromagnetic moments of hadrons and quarks in a hybrid model
International Nuclear Information System (INIS)
Gerasimov, S.B.
1989-01-01
Magnetic moments of baryons are analyzed on the basis of general sum rules following from the theory of broken symmetries and quark models including the relativistic effects and hadronic corrections due to the meson exchange currents. A new sum rule is proposed for the hyperon magnetic moments, which is in accord with the most precise new data and also with a theory of the electromagnetic ΛΣ 0 mixing. The numerical values of the quark electromagnetic moments are obtained within a hybrid model treating the pion cloud effects through the local coupling of the pion field with the constituent massive quarks. Possible sensitivity of the weak neutral current magnetic moments to violation of the Okubo-Zweig-Izuki rule is emphasized nand discussed. 39 refs.; 1 fig
Czech Academy of Sciences Publication Activity Database
Suk, Tomáš; Flusser, Jan
2004-01-01
Roč. 26, č. 10 (2004), s. 1364-1367 ISSN 0162-8828 R&D Projects: GA ČR GA201/03/0675 Institutional research plan: CEZ:AV0Z1075907 Keywords : projective transform * moment invariants * object recognition Subject RIV: JD - Computer Applications, Robotics Impact factor: 4.352, year: 2004 http://library.utia.cas.cz/prace/20040112.pdf
Spontaneous vortex phase (SVP) of ruthenocuprate high Tc ...
Indian Academy of Sciences (India)
RuSr2(RE1.5Ce0.5)Cu2O10, has given rise to the concept of spontaneous vortex phase (SVP). In these compounds, the magnetic ordering temperature (Tmag >. 100 K) is higher than the superconducting transition temperature (Tc ~ 30 K). Hence, due to internal magnetic fields, these compounds remain in a spontaneous.
Distributions on unbounded moment spaces and random moment sequences
Dette, Holger; Nagel, Jan
2012-01-01
In this paper we define distributions on moment spaces corresponding to measures on the real line with an unbounded support. We identify these distributions as limiting distributions of random moment vectors defined on compact moment spaces and as distributions corresponding to random spectral measures associated with the Jacobi, Laguerre and Hermite ensemble from random matrix theory. For random vectors on the unbounded moment spaces we prove a central limit theorem where the centering vecto...
Theory of anisotropic diamagnetism, local moment magnetization ...
Indian Academy of Sciences (India)
Department of Physics, S.K.C.G College, Parlakhemundi 761 200, India; Department of Physics, Gopalpur College, Gopalpur 761 002, India; Department of Physics, Jagannath Institute for Technology and Management, Parlakhemundi 761 211, India; Department of Physics, Berhampur University, Berhampur 760 007, India ...
Two component theory and electron magnetic moment
Veltman, M.J.G.
1998-01-01
The two-component formulation of quantum electrodynamics is studied. The relation with the usual Dirac formulation is exhibited, and the Feynman rules for the two-component form of the theory are presented in terms of familiar objects. The transformation from the Dirac theory to the two-component
The anomalous magnetic moment of the muon
Hughes, V W; Earle, W; Efstathiadis, E F; Hare, M; Hazen, E S; Krienen, F; Miller, J P; Rind, O; Roberts, B L; Sulak, Lawrence R; Trofimov, A V; Brown, H N; Bunce, G M; Danby, G T; Larsen, R; Lee, Y Y; Meng, W; Mi, J L; Morse, W M; Pai, C; Prigl, R; Sanders, R; Semertzidis, Y K; Tanaka, M; Warburton, D; Orlov, Yu F; Winn, D; Grossmann, A; Jungmann, Klaus; zu Putlitz, Gisbert; Debevec, P T; Deninger, W; Hertzog, D W; Polly, C; Sedykh, S; Urner, D; Haeberlen, U; Cushman, P B; Duong, L; Giron, S; Kindem, J; McNabb, R; Miller, D; Timmermans, C; Zimmerman, D; Druzhinin, V P; Fedotovich, G V; Khazin, B I; Logashenko, I B; Ryskulov, N M; Serednyakov, S I; Shatunov, Yu M; Solodov, E P; Yamamoto, A; Iwasaki, M; Kawamura, M; Deng, H; Dhawan, S K; Farley, Francis J M; Grosse-Perdekamp, M; Hughes, V W; Kawall, D; Redin, S I; Steinmetz, A
1998-01-01
A new experiment is underway at Brookhaven National Laboratory to measure the g-2 value of the muon to a precision of 0.35 ppm, which would improve our present knowledge by a factor of 20. In its initial run the muon anomalous g-value was found to be a/sub mu //sup + /=1165925(15)*10/sup -9/ [13 ppm], in good agreement with the previous CERN measurements and with approximately the same uncertainty. The current scientific motivations for this experiment are discussed, and the experiment is described. (30 refs).
Magnetic and structural properties of the magnetic shape memory compound Ni2Mn1.48Sb0.52
International Nuclear Information System (INIS)
Brown, P J; Gandy, A P; Neumann, K U; Sheikh, A; Ziebeck, K R A; Ishida, K; Oikawa, K; Ito, W; Kainuma, R; Kanomata, T; Ouladdiaf, B
2010-01-01
Magnetization and high resolution neutron powder diffraction measurements on the magnetic shape memory compound Ni 2 Mn 1.48 Sb 0.52 have confirmed that it is ferromagnetic below 350 K and undergoes a structural phase transition at T M ∼310 K. The high temperature phase has the cubic L2 1 structure with a = 5.958 A, with the excess manganese atoms occupying the 4(b) Sb sites. In the cubic phase above ∼310 K the manganese moments are ferromagnetically aligned. The magnetic moment at the 4(a) site is 1.57(12) μ B and it is almost zero (0.15(9) μ B ) at the 4(b) site. The low temperature orthorhombic phase which is only fully established below 50 K has the space group Pmma with a cell related to the cubic one by a Bain transformation a orth = (a cub + b cub )/2; b orth = c cub and c orth = (a cub - b cub ). The change in cell volume is ∼2.5%. The spontaneous magnetization of samples cooled in fields less than 0.5 T decreases at temperatures below T M and at 2 K the magnetic moment per formula unit in fields up to 5.5 T is 2.01(5) μ B . Neutron diffraction patterns obtained below ∼132 K gave evidence for a weak incommensurate magnetic modulation with propagation vector (2/3, 1/3, 0).
International Nuclear Information System (INIS)
Young, I.R.
1984-01-01
A magnet pole piece for an NMR imaging magnet is made of a plurality of magnetic wires with one end of each wire held in a non-magnetic spacer, the other ends of the wires being brought to a pinch, and connected to a magnetic core. The wires may be embedded in a synthetic resin and the magnetisation and uniformity thereof can be varied by adjusting the density of the wires at the spacer which forms the pole piece. (author)
Induced moment due to perpendicular field cycling in trained ...
Indian Academy of Sciences (India)
This induced magnetism into the AF layer is unique in its nature as it results from direct manipulation of the uncompensated moments at the AF–FM interface. Such manipulation obviously fails to restore the untrained state [10]. One may note that all the structural as well as magnetic properties are initially estimated.
Face recognition using Krawtchouk moment
Indian Academy of Sciences (India)
Abstract. Feature extraction is one of the important tasks in face recognition. Moments are widely used feature extractor due to their superior discriminatory power and geometrical invariance. Moments generally capture the global features of the image. This paper proposes Krawtchouk moment for feature extraction in face ...
Face recognition using Krawtchouk moment
Indian Academy of Sciences (India)
2016-08-26
Aug 26, 2016 ... Feature extraction is one of the important tasks in face recognition. Moments are widely used feature extractor due to their superior discriminatory power and geometrical invariance. Moments generally capture the global features of the image. This paper proposes Krawtchouk moment for feature extraction ...
Bennemann, K. H.
2010-01-01
Characteristic results of magnetism in small particles and thin films are presented. As a consequence of the reduced atomic coordination in small clusters and thin films the electronic states and density of states modify. Thus magnetic moments and magnetization are affected. In tunnel junctions interplay of magnetism, spin currents and superconductivity are of particular interest. Results are given for single transition metal clusters, cluster ensembles, thin films and tunnel systems. Interes...
Manifestation of the cyclo-toroid nuclear moment in anomalous conversion and Lamb shift
Tkalya, E. V.
2005-01-01
We offer the hypothesis that atomic nuclei, nucleons, and atoms possess a new type of electromagnetic moment, that we call a ``cyclo-toroid moment''. In nuclei, this moment arises when the toroid dipole (anapole) moments are arrayed in the form of a ring, or, equivalently, when the magnetic moments of the nucleons are arranged in the form of rings which, in turn, constitute the surface of a torus. We establish theoretically that the cyclo-toroid moment plays a role in the processes of the ato...
Possibility of third-order magnetic susceptibility investigations in magnetic materials
International Nuclear Information System (INIS)
Bazhan, A.N.
2004-01-01
Three-coordinate vector magnetometer for investigations of the magnetic field dependencies of the three separate magnetic moment components, along and perpendicular to the applied magnetic field, is described. Additionally to investigations of the sample magnetic moments orientations with respect to sample axis in magnetically ordered materials, possibilities in investigations of non-linear magnetic field dependencies of sample magnetic moments components of some paramagnetic materials are discussed
Energy Technology Data Exchange (ETDEWEB)
Correll, F.D.; Madansky, L.; Hardekopf, R.A.; Sunier, J.W.
1983-08-01
The ground-state magnetic dipole and electric quadrupole moments of the ..beta.. emitter /sup 9/Li (J/sup ..pi../ = (3/2)/sup -/, T/sub 1/2/ = 0.176 s) have been measured for the first time. Polarized /sup 9/Li nuclei were produced in the /sup 7/Li(t,p) reaction, using 5--6 MeV polarized tritons. The recoiling /sup 9/Li nuclei were stopped either in Au foils or in LiNbO/sub 3/ single crystals, and their polarization was detected by measuring the ..beta..-decay asymmetry. Nuclear magnetic resonance techniques were used to depolarize the nuclei, and the resonant frequencies were deduced from changes in the asymmetry. The /sup 9/Li dipole moment was deduced from the measured Larmor frequency in Au; the result, including corrections for diamagnetic shielding and the Knight shift, is Vertical Bar..mu..Vertical Bar = 3.4391(6) ..mu../sub N/. The ratio of the /sup 9/Li quadrupole moment to that of /sup 7/Li was derived from their respective quadrupole couplings in LiNbO/sub 3/; the value is Vertical BarQ( /sup 9/Li)/Q( /sup 7/Li)Vertical Bar = 0. 88 +- 0.18. Both results are in agreement with shell model predictions.
SELECTION MOMENTS AND GENERALIZED METHOD OF MOMENTS FOR HETEROSKEDASTIC MODELS
Directory of Open Access Journals (Sweden)
Constantin ANGHELACHE
2016-06-01
Full Text Available In this paper, the authors describe the selection methods for moments and the application of the generalized moments method for the heteroskedastic models. The utility of GMM estimators is found in the study of the financial market models. The selection criteria for moments are applied for the efficient estimation of GMM for univariate time series with martingale difference errors, similar to those studied so far by Kuersteiner.
Spontaneous emission of an atom in the presence of a plasmonic cloaking sphere
International Nuclear Information System (INIS)
Kort-Kamp, W.J.M.; Rosa, F.S.S.; Pinheiro, F.A.; Farina, Carlos
2012-01-01
Full text: Cavity Quantum Electrodynamics (CQED) consists, essentially, in the study of the influence of the neighborhood of an atomic system in its radiative properties. The purpose of this kind of study is not only to obtain more precise results for atomic quantities like the anomalous magnetic moment of the electron, but also to control the radiative properties of the system as, for example, the atomic transition frequencies or the natural line widths. Particularly, spontaneous emission rates, which are directly related to the natural line widths, may be enhanced, weakened or even suppressed due to the presence of appropriately arranged perfectly conducting walls in the vicinity of the atomic system. The work considered as a landmark of CQED, presented in a conference of the American Physical Society by Purcell in 1946, was precisely about this kind of influence. Purcell showed that the spontaneous emission associated to nuclear magnetic dipole transitions could be enhanced if the system were appropriately coupled to a resonant external electric circuit. Nowadays, there are several studies about the influence in the spontaneous emission rate of an atom due to the presence of new materials in its neighborhood. Particularly, the so-called metamaterials, the name given to material structures artificially constructed with desired electromagnetic properties, give rise to a new way of controlling the radiative properties of an atomic system.In the present work, after making a brief introduction on spontaneous emission, which includes the calculation of Einstein's coefficient in some simple cases as, for example, an atom embedded in a negative refractive index metamaterial, we discuss how the spontaneous emission rate of a two level atom is altered due to the presence of a plasmonic cloaking sphere. Among other things, our result shows that the emission rate exhibits an oscillatory behavior with the mutual distance between the atom and sphere. Also, we show that for a
Solar wind velocity and geomagnetic moment variations
International Nuclear Information System (INIS)
Kalinin, Yu.D.; Rozanova, T.S.
1982-01-01
The mean year values of the solar wind velocity have been calculated from the mean-year values of a geomagnetic activity index am according to the Svalgard equation of regression for the pe-- riod from 1930 to 1960. For the same years the values of the geomagnetic moment M and separately of its ''inner'' (causes of which'' are inside the Earth) and ''external'' (causes of which are outside the Earth) parts have been calculated from the mean year data of 12 magnetic observatories. The proof of the presence of the 11-year variation in the moment M has been obtained. It is concluded that the 11-year variations in M result from the variations of the solar wind velocity
Spontaneous pneumothorax in weightlifters.
Marnejon, T; Sarac, S; Cropp, A J
1995-06-01
Spontaneous pneumothorax is infrequently caused by strenuous exertion. To our knowledge there has only been one case of spontaneous pneumothorax associated with weightlifting reported in the medical literature. We describe three consecutive cases of spontaneous pneumothorax associated with weightlifting. We postulate that spontaneous pneumothorax in these patients may be secondary to improper breathing techniques. It is important that physicians and weight trainers be aware of the association between weight lifting and spontaneous pneumothorax and assure that proper instruction is given to athletes who work with weights.
by B. Curé
2011-01-01
The magnet operation was very satisfactory till the technical stop at the end of the year 2010. The field was ramped down on 5th December 2010, following the successful regeneration test of the turbine filters at full field on 3rd December 2010. This will limit in the future the quantity of magnet cycles, as it is no longer necessary to ramp down the magnet for this type of intervention. This is made possible by the use of the spare liquid Helium volume to cool the magnet while turbines 1 and 2 are stopped, leaving only the third turbine in operation. This obviously requires full availability of the operators to supervise the operation, as it is not automated. The cryogenics was stopped on 6th December 2010 and the magnet was left without cooling until 18th January 2011, when the cryoplant operation resumed. The magnet temperature reached 93 K. The maintenance of the vacuum pumping was done immediately after the magnet stop, when the magnet was still at very low temperature. Only the vacuum pumping of the ma...
Spontaneous intracranial hypotension
International Nuclear Information System (INIS)
Haritanti, A.; Karacostas, D.; Drevelengas, A.; Kanellopoulos, V.; Paraskevopoulou, E.; Lefkopoulos, A.; Economou, I.; Dimitriadis, A.S.
2009-01-01
Spontaneous intracranial hypotension (SIH) is an uncommon but increasingly recognized syndrome. Orthostatic headache with typical findings on magnetic resonance imaging (MRI) are the key to diagnosis. Delayed diagnosis of this condition may subject patients to unnecessary procedures and prolong morbidity. We describe six patients with SIH and outline the important clinical and neuroimaging findings. They were all relatively young, 20-54 years old, with clearly orthostatic headache, minimal neurological signs (only abducent nerve paresis in two) and diffuse pachymeningeal gadolinium enhancement on brain MRI, while two of them presented subdural hygromas. Spinal MRI was helpful in detecting a cervical cerebrospinal fluid leak in three patients and dilatation of the vertebral venous plexus with extradural fluid collection in another. Conservative management resulted in rapid resolution of symptoms in five patients (10 days-3 weeks) and in one who developed cerebral venous sinus thrombosis, the condition resolved in 2 months. However, this rapid clinical improvement was not accompanied by an analogous regression of the brain MR findings that persisted on a longer follow-up. Along with recent literature data, our patients further point out that SIH, to be correctly diagnosed, necessitates increased alertness by the attending physician, in the evaluation of headaches
Spontaneous lateral temporal encephalocele.
Tuncbilek, Gokhan; Calis, Mert; Akalan, Nejat
2013-01-01
A spontaneous encephalocele is one that develops either because of embryological maldevelopment or from a poorly understood postnatal process that permits brain herniation to occur. We here report a rare case of lateral temporal encephalocele extending to the infratemporal fossa under the zygomatic arch. At birth, the infant was noted to have a large cystic mass in the right side of the face. After being operated on initially in another center in the newborn period, the patient was referred to our clinic with a diagnosis of temporal encephalocele. He was 6 months old at the time of admission. Computerized tomography scan and magnetic resonance imaging studies revealed a 8 × 9 cm fluid-filled, multiloculated cystic mass at the right infratemporal fossa. No intracranial pathology or connection is seen. The patient was operated on to reduce the distortion effect of the growing mass. The histopathological examination of the sac revealed well-differentiated mature glial tissue stained with glial fibrillary acid protein. This rare clinical presentation of encephaloceles should be taken into consideration during the evaluation of the lateral facial masses in the infancy period, and possible intracranial connection should be ruled out before surgery to avoid complications.
Spontaneous sensorimotor coupling with multipart music.
Hurley, Brian K; Martens, Peter A; Janata, Petr
2014-08-01
Music often evokes spontaneous movements in listeners that are synchronized with the music, a phenomenon that has been characterized as being in "the groove." However, the musical factors that contribute to listeners' initiation of stimulus-coupled action remain unclear. Evidence suggests that newly appearing objects in auditory scenes orient listeners' attention, and that in multipart music, newly appearing instrument or voice parts can engage listeners' attention and elicit arousal. We posit that attentional engagement with music can influence listeners' spontaneous stimulus-coupled movement. Here, 2 experiments-involving participants with and without musical training-tested the effect of staggering instrument entrances across time and varying the number of concurrent instrument parts within novel multipart music on listeners' engagement with the music, as assessed by spontaneous sensorimotor behavior and self-reports. Experiment 1 assessed listeners' moment-to-moment ratings of perceived groove, and Experiment 2 examined their spontaneous tapping and head movements. We found that, for both musically trained and untrained participants, music with more instruments led to higher ratings of perceived groove, and that music with staggered instrument entrances elicited both increased sensorimotor coupling and increased reports of perceived groove. Although untrained participants were more likely to rate music as higher in groove, trained participants showed greater propensity for tapping along, and they did so more accurately. The quality of synchronization of head movements with the music, however, did not differ as a function of training. Our results shed new light on the relationship between complex musical scenes, attention, and spontaneous sensorimotor behavior.
Energy Technology Data Exchange (ETDEWEB)
Yang, Ning [Iowa State Univ., Ames, IA (United States)
2004-12-19
Thermal expansion anomalies of R_{2}Fe_{14}B and R_{2}Fe_{17}C_{x} (x = 0,2) (R = Y, Nd, Gd, Tb, Er) stoichiometric compounds are studied with high-energy synchrotron X-ray powder diffraction using Debye-Schemer geometry in temperature range 10K to 1000K. Large spontaneous magnetostriction up to their Curie temperatures (T_{c}) is observed. The a-axes show relatively larger invar effects than c-axes in the R_{2}Fe_{14}B compounds whereas the R_{2}Fe_{17}C_{x} show the contrary anisotropies. The iron sub-lattice is shown to dominate the spontaneous magnetostriction of the compounds. The contribution of the rare earth sublattice is roughly proportional to the spin magnetic moment of the rare earth in the R_{2}Fe_{14}B compounds but in R_{2}Fe_{17}C_{x}, the rare earth sub-lattice contribution appears more likely to be dominated by the local bonding. The calculation of spontaneous magnetostrain of bonds shows that the bonds associated with Fe(j2) sites in R_{2}Fe_{14}B and the dumbbell sites in R_{2}Fe_{17}C_{x} have larger values, which is strongly related to their largest magnetic moment and Wigner-Seitz atomic cell volume. The roles of the carbon atoms in increasing the Curie temperatures of the R_{2}Fe_{17} compounds are attributed to the increased separation of Fe hexagons. The R_{2}Fe_{17} and R_{2}Fe_{14}B phases with magnetic rare earth ions also show anisotropies of thermal expansion above_{ c}. For R_{2}Fe_{17} and R_{2}Fe_{14}B the a_{ a}/a_{ c} > 1 whereas the anisotropy is reversed with the interstitial carbon in R_{2}Fe_{17}. The average bond magnetostrain is shown to be a possible predictor of the magnetic moment of Fe sites in the compounds. Both of the theoretical and
B. Curé
2012-01-01
Following the unexpected magnet stops last August due to sequences of unfortunate events on the services and cryogenics [see CMS internal report], a few more events and initiatives again disrupted the magnet operation. All the magnet parameters stayed at their nominal values during this period without any fault or alarm on the magnet control and safety systems. The magnet was stopped for the September technical stop to allow interventions in the experimental cavern on the detector services. On 1 October, to prepare the transfer of the liquid nitrogen tank on its new location, several control cables had to be removed. One cable was cut mistakenly, causing a digital input card to switch off, resulting in a cold-box (CB) stop. This tank is used for the pre-cooling of the magnet from room temperature down to 80 K, and for this reason it is controlled through the cryogenics control system. Since the connection of the CB was only allowed for a field below 2 T to avoid the risk of triggering a fast d...
B. Curé
2012-01-01
The magnet was energised at the beginning of March 2012 at a low current to check all the MSS safety chains. Then the magnet was ramped up to 3.8 T on 6 March 2012. Unfortunately two days later an unintentional switch OFF of the power converter caused a slow dump. This was due to a misunderstanding of the CCC (CERN Control Centre) concerning the procedure to apply for the CMS converter control according to the beam-mode status at that time. Following this event, the third one since 2009, a discussion was initiated to define possible improvement, not only on software and procedures in the CCC, but also to evaluate the possibility to upgrade the CMS hardware to prevent such discharge from occurring because of incorrect procedure implementations. The magnet operation itself was smooth, and no power cuts took place. As a result, the number of magnetic cycles was reduced to the minimum, with only two full magnetic cycles from 0 T to 3.8 T. Nevertheless the magnet suffered four stops of the cryogeni...
Benoit Curé
2010-01-01
Operation of the magnet has gone quite smoothly during the first half of this year. The magnet has been at 4.5K for the full period since January. There was an unplanned short stop due to the CERN-wide power outage on May 28th, which caused a slow dump of the magnet. Since this occurred just before a planned technical stop of the LHC, during which access in the experimental cavern was authorized, it was decided to leave the magnet OFF until 2nd June, when magnet was ramped up again to 3.8T. The magnet system experienced a fault also resulting in a slow dump on April 14th. This was triggered by a thermostat on a filter choke in the 20kA DC power converter. The threshold of this thermostat is 65°C. However, no variation in the water-cooling flow rate or temperature was observed. Vibration may have been the root cause of the fault. All the thermostats have been checked, together with the cables, connectors and the read out card. The tightening of the inductance fixations has also been checked. More tem...
Dix, Nico; Muralidharan, Rajaram; Rebled, Jose-Manuel; Estradé, Sonia; Peiró, Francesca; Varela, Manuel; Fontcuberta, Josep; Sánchez, Florencio
2010-08-24
We demonstrate that epitaxial strain engineering is an efficient method to manipulate the ferromagnetic and ferroelectric properties in BiFeO(3)-CoFe(2)O(4) columnar nanocomposites. On one hand, the magnetic anisotropy of CoFe(2)O(4) is totally tunable from parallel to perpendicular controlling the CoFe(2)O(4) strain with proper combinations of substrate and ferroelectric phase. On the other hand, the selection of the used substrate allows the growth of the rhombohedral bulk phase of BiFeO(3) or the metastable nearly tetragonal one, which implies a rotation of the ferroelectric polar axis from [111] to close to the [001] direction. Remarkably, epitaxy is preserved and interfaces are semicoherent even when lattice mismatch is above 10%. The broad range of sustainable mismatch suggests new opportunities to assemble epitaxial nanostructures combining highly dissimilar materials with distinct functionalities.
Moment Magnitude discussion in Austria
Weginger, Stefan; Jia, Yan; Hausmann, Helmut; Lenhardt, Wolfgang
2017-04-01
We implemented and tested the Moment Magnitude estimation „dbmw" from the University of Trieste in our Antelope near real-time System. It is used to get a fast Moment Magnitude solutions and Ground Motion Parameter (PGA, PGV, PSA 0.3, PSA 1.0 and PSA 3.0) to calculate Shake and Interactive maps. A Moment Magnitude Catalogue was generated and compared with the Austrian Earthquake Catalogue and all available Magnitude solution of the neighbouring agencies. Relations of Mw to Ml and Ground Motion to Intensity are presented.
Dimensional reduction and moment maps
Nagatomo, Yasuyuki
2002-03-01
We give a unified viewpoint of moment maps in the case of symplectic, hyper-Kähler, quaternion-Kähler and holomorphic contact manifolds. The Higgs field can be regarded as a moment map under some additional conditions in each case. Using dimensional reductions and moment maps, we reduce the standard 1 instanton on HP 1≅S 4 to an SO(3) instanton on CP 1× CP 1 and the standard 1 instanton on HP n to the standard 1 instanton on Gr 2( Cn+1) .
Lepton Dipole Moments in Supersymmetric Low-Scale Seesaw Models
Ilakovac, Amon; Popov, Luka
2014-01-01
We study the anomalous magnetic and electric dipole moments of charged leptons in supersymmetric low-scale seesaw models with right-handed neutrino superfields. We consider a minimally extended framework of minimal supergravity, by assuming that CP violation originates from complex soft SUSY-breaking bilinear and trilinear couplings associated with the right-handed sneutrino sector. We present numerical estimates of the muon anomalous magnetic moment and the electron electric dipole moment (EDM), as functions of key model parameters, such as the Majorana mass scale mN and tan(\\beta). In particular, we find that the contributions of the singlet heavy neutrinos and sneutrinos to the electron EDM are naturally small in this model, of order 10^{-27} - 10^{-28} e cm, and can be probed in the present and future experiments.
B. Curé
2013-01-01
The magnet was operated without any problem until the end of the LHC run in February 2013, apart from a CERN-wide power glitch on 10 January 2013 that affected the CMS refrigerator, causing a ramp down to 2 T in order to reconnect the coldbox. Another CERN-wide power glitch on 15 January 2013 didn’t affect the magnet subsystems, the cryoplant or the power converter. At the end of the magnet run, the reconnection of the coldbox at 2.5 T was tested. The process will be updated, in particular the parameters of some PID valve controllers. The helium flow of the current leads was reduced but only for a few seconds. The exercise will be repeated with the revised parameters to validate the automatic reconnection process of the coldbox. During LS1, the water-cooling services will be reduced and many interventions are planned on the electrical services. Therefore, the magnet cryogenics and subsystems will be stopped for several months, and the magnet cannot be kept cold. In order to avoid unc...
Benoit Curé
2010-01-01
The magnet was successfully operated at the end of the year 2009 despite some technical problems on the cryogenics. The magnet was ramped up to 3.8 T at the end of November until December 16th when the shutdown started. The magnet operation met a few unexpected stops. The field was reduced to 3.5 T for about 5 hours on December 3rd due to a faulty pressure sensor on the helium compressor. The following day the CERN CCC stopped unintentionally the power converters of the LHC and the experiments, triggering a ramp down that was stopped at 2.7 T. The magnet was back at 3.8 T about 6 hours after CCC sent the CERN-wide command. Three days later, a slow dump was triggered due to a stop of the pump feeding the power converter water-cooling circuit, during an intervention on the water-cooling plant done after several disturbances on the electrical distribution network. The magnet was back at 3.8 T in the evening the same day. On December 10th a break occurred in one turbine of the cold box producing the liquid ...
B. Curé
2011-01-01
The CMS magnet has been running steadily and smoothly since the summer, with no detected flaw. The magnet instrumentation is entirely operational and all the parameters are at their nominal values. Three power cuts on the electrical network affected the magnet run in the past five months, with no impact on the data-taking as the accelerator was also affected at the same time. On 22nd June, a thunderstorm caused a power glitch on the service electrical network. The primary water cooling at Point 5 was stopped. Despite a quick restart of the water cooling, the inlet temperature of the demineralised water on the busbar cooling circuit increased by 5 °C, up to 23.3 °C. It was kept below the threshold of 27 °C by switching off other cooling circuits to avoid the trigger of a slow dump of the magnet. The cold box of the cryogenics also stopped. Part of the spare liquid helium volume was used to maintain the cooling of the magnet at 4.5 K. The operators of the cryogenics quickly restarted ...
B. Curé
2012-01-01
The magnet and its sub-systems were stopped at the beginning of the winter shutdown on 8th December 2011. The magnet was left without cooling during the cryogenics maintenance until 17th January 2012, when the cryoplant operation resumed. The magnet temperature reached 93 K. The vacuum pumping was maintained during this period. During this shutdown, the yearly maintenance was performed on the cryogenics, the vacuum pumps, the magnet control and safety systems, and the power converter and discharge lines. Several preventive actions led to the replacement of the electrovalve command coils, and the 20A DC power supplies of the magnet control system. The filters were cleaned on the demineralised water circuits. The oil of the diffusion pumps was changed. On the cryogenics, warm nitrogen at 343 K was circulated in the cold box to regenerate the filters and the heat exchangers. The coalescing filters have been replaced at the inlet of both the turbines and the lubricant trapping unit. The active cha...
Noteworthy moments and people!
Claudia Marcelloni de Oliveira
The man with nerves of steel and one steady finger: Gerard Mouquin operating the main crane with a joy-stick-like remote control while the 220-ton End-Cap Toroid Magnet is suspended mid-air above the access shaft. His job was hanging by a thread... The woman with nerves of steel: Sylvie Prodon, head of the logistic section responsible for all transport at CERN was supervising the delicate operation of taking the first End-Cap Toroid down to the ATLAS cavern. The sight from Side A after complete insertion of the Inner Detector End-Cap A and pushing back the End-Cap Calorimeter into place, making room for the Toroid End-Cap A. Lots of pondering took place during the testing of the pixel insertion procedure. The tooling which will be used in the cavern to insert the pixel within the silicon detector was fully tested at the surface in the SR1 building by having the whole detector passing through the insertion template when the pixel detector was placed within its transportation carriage. The...
Absence of toroidal moments in 'aromagnetic' anthracene
Energy Technology Data Exchange (ETDEWEB)
Alborghetti, S; Coey, J M D [School of Physics, Trinity College, Dublin 2 (Ireland); Puppin, E; Brenna, M; Pinotti, E; Zanni, P [Dipartimento di Fisica, Politecnico di Milano, Milano (Italy)], E-mail: alborgs@tcd.ie
2008-06-15
Colloidal suspensions of anthracene and other aromatic compounds have been shown to respond to a magnetic field as if they possessed a permanent magnetic moment. This phenomenon was named 'aromagnetism' by Spartakov and Tolstoi, and it was subsequently attributed to the interaction of an electric toroidal moment with a time-varying magnetic field. However, there has been no independent confirmation of the original work. Here, we have selected purified anthracene crystallites which respond to a low magnetic field and investigate how this response depends on the gradient and the time derivative of the field. We conclude that the anomaly cannot be attributed to a toroidal interaction but is due to a constant magnetic moment of the particles. Close examinations using magnetometry and scanning electron microscopy reveal metallic clusters of Fe and Ni up to a few hundred nanometres in size embedded in the anomalous crystallites. These inclusions represent 1.8 ppm by weight of the sample. The observed presence of ferromagnetic inclusions in the ppm range is sufficient to explain the anomalous magnetic properties of micron-sized anthracene crystals, including the reported optical properties of the colloidal suspensions.
Directory of Open Access Journals (Sweden)
Yongxin Li
2017-08-01
Full Text Available For some patients with medically refractory epilepsy (MRE, surgery is a safe and effective treatment for controlling epilepsy. However, the functional consequences of such surgery on brain activity and connectivity in children remain unknown. In the present study, we carried out a longitudinal study using resting-state functional magnetic resonance imaging in 10 children with MRE before and again at a mean of 79 days after surgery, as well as in a group of 28 healthy controls. Compared with the controls, children with epilepsy exhibited abnormalities in intrinsic activity in the thalamus, putamen, pallidum, insula, hippocampus, cerebellum, and cingulate gyrus both before and after surgery. Longitudinal analyses showed that the amplitude of low frequency fluctuations (ALFF increased in the parietal–frontal cortex and decreased in the deep nuclei from pre- to post-surgery. The percentage changes in ALFF values in the deep nuclei were positively correlated with the age of epilepsy onset. Functional connectivity (FC analyses demonstrated a reorganization of FC architecture after surgery. These changes in brain activity and FC after surgery might indicate that the previously disrupted functional interactions were reorganized after surgery. All these results provide preliminary evidence that the age of epilepsy onset may have some potential to predict the outcome of brain functional reorganization after surgery in children with MRE.
Fast computation of Krawtchouk moments
Czech Academy of Sciences Publication Activity Database
Honarvar Shakibaei Asli, B.; Flusser, Jan
2014-01-01
Roč. 288, č. 1 (2014), s. 73-86 ISSN 0020-0255 R&D Projects: GA ČR GAP103/11/1552 Institutional support: RVO:67985556 Keywords : Krawtchouk polynomial * Krawtchouk moment * Geometric moment * Impulse response * Fast computation * Digital filter Subject RIV: JD - Computer Applications, Robotics Impact factor: 4.038, year: 2014 http://library.utia.cas.cz/separaty/2014/ZOI/flusser-0432452.pdf
Moment Distributions of Phase Type
DEFF Research Database (Denmark)
Bladt, Mogens; Nielsen, Bo Friis
2011-01-01
Moment distributions of phase-type and matrix-exponential distributions are shown to remain within their respective classes. We provide a probabilistic phase-type representation for the former case and an alternative representation, with an analytically appealing form, for the latter. First order...... moment distributions are of special interest in areas like demography and economics, and we calculate explicit formulas for the Lorenz curve and Gini index used in these disciplines....
African Journals Online (AJOL)
ABSTRACT. Rupture of a gravid uterus is a surgical emergency. Predisposing factors include a scarred uterus. Spontaneous rupture of an unscarred uterus during pregnancy is a rare occurrence. We hereby present the case of a spontaneous complete uterine rupture at a gestational age of 34 weeks in a 35 year old patient ...
International Nuclear Information System (INIS)
Syimonova, L.Yi.; Byilogurova, L.V.; Gertman, V.Z.; Kurov, O.M.
2012-01-01
Local x-ray exposure of the rats at a dose of 50.0 Gy caused development of radiation dermatitis with imperfect skin healing with scars and incomplete restoration of the fleece as a consequence. Administration of photon-magnetic therapy positively influenced healing of skin radiation lesions in locally irradiated animals
B. Curé
2011-01-01
The magnet ran smoothly in the last few months until a fast dump occurred on 9th May 2011. Fortunately, this occurred in the afternoon of the first day of the technical stop. The fast dump was due to a valve position controller that caused the sudden closure of a valve. This valve is used to regulate the helium flow on one of the two current leads, which electrically connects the coil at 4.5 K to the busbars at room temperature. With no helium flow on the lead, the voltage drop and the temperatures across the leads increase up to the defined thresholds, triggering a fast dump through the Magnet Safety System (MSS). The automatic reaction triggered by the MSS worked properly. The helium release was limited as the pressure rise was just at the limit of the safety valve opening pressure. The average temperature of the magnet reached 72 K. It took four days to recover the temperature and refill the helium volumes. The faulty valve controller was replaced by a spare one before the magnet ramp-up resumed....
Study of electromagnetic moments in unstable nuclei with radioactive nuclear beams
International Nuclear Information System (INIS)
Asahi, K; Kameda, D; Ueno, H; Yoshimi, A; Uchida, M; Miyoshi, H; Shimada, K; Nagae, D; Kijima, G; Haseyama, T; Watanabe, H; Takemura, M; Arai, T; Oshima, S; Umeya, A
2005-01-01
The measurements of nuclear moments have been conducted at RIKEN for the study of nuclei far from the β stability. Recent results for the magnetic moments of 30 Al and 32 Al obtained by means of β-NMR spectroscopy with spin-polarized radioactive beams from the projectile fragmentation reaction are presented. Remarks are also made on the developments and prospects for future moment studies at the RI Beam Factory
Image Recognition Using Modified Zernike Moments
Directory of Open Access Journals (Sweden)
Min HUANG
2014-03-01
Full Text Available Zernike moments are complex moments with the orthogonal Zernike polynomials as kernel function, compared with other moments; Zernike moments have greater advantages in image rotation and low noise sensitivity. Because of the Zernike moments have image rotation invariance, and can construct arbitrary high order moments, it can be used for target recognition. In this paper, the Zernike moment algorithm is improved, which makes it having scale invariance in the processing of digital image. At last, an application of the improved Zernike moments in image recognition is given.
τ dipole moments via radiative leptonic τ decays
Energy Technology Data Exchange (ETDEWEB)
Eidelman, S. [Budker Institute of Nuclear Physics SB RAS,Novosibirsk 630090 (Russian Federation); Novosibirsk State University,Novosibirsk 630090 (Russian Federation); Epifanov, D. [Budker Institute of Nuclear Physics SB RAS,Novosibirsk 630090 (Russian Federation); Novosibirsk State University,Novosibirsk 630090 (Russian Federation); The University of Tokyo,7-3-1 Hongo Bunkyo-ku, Tokyo 113-0033 (Japan); Fael, M. [Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics,University of Bern, CH-3012 Bern (Switzerland); Mercolli, L. [Federal Office of Public Health FOPH,CH-3003 Bern (Switzerland); Passera, M. [INFN - Sezione di Padova,I-35131 Padova (Italy)
2016-03-21
We propose a new method to probe the magnetic and electric dipole moments of the τ lepton using precise measurements of the differential rates of radiative leptonic τ decays at high-luminosity B factories. Possible deviations of these moments from the Standard Model values are analyzed in an effective Lagrangian approach, thus providing model-independent results. Analytic expressions for the relevant non-standard contributions to the differential decay rates are presented. Earlier proposals to probe the τ dipole moments are examined. A detailed feasibility study of our method is performed in the conditions of the Belle and Belle II experiments at the KEKB and Super-KEKB colliders, respectively. This study shows that our approach, applied to the planned full set of Belle II data for radiative leptonic τ decays, has the potential to improve the present experimental bound on the τ anomalous magnetic moment. On the contrary, its foreseen sensitivity is not expected to lower the current experimental limit on the τ electric dipole moment.
Magnetic and Magnetoelectric Properties of Rare Earth Molybdates
Directory of Open Access Journals (Sweden)
B. K. Ponomarev
2012-01-01
Full Text Available We present results on ferroelectric, magnetic, magneto-optical properties and magnetoelectric effect of rare earth molybdates (gadolinium molybdate, GMO, and terbium molybdate, TMO, and samarium molybdate, SMO, belonging to a new type of ferroelectrics predicted by Levanyuk and Sannikov. While cooling the tetragonal β-phase becomes unstable with respect to two degenerate modes of lattice vibrations. The β-β′ transition is induced by this instability. The spontaneous polarization appears as a by-product of the lattice transformation. The electric order in TMO is of antiferroelectric type. Ferroelectric and ferroelastic GMO and TMO at room temperature are paramagnets. At low temperatures GMO and TMO are antiferromagnetic with the Neel temperatures TN=0.3 K (GMO and TN=0.45 K (TMO. TMO shows the spontaneous destruction at 40 kOe magnetic field. Temperature and field dependences of the magnetization in TMO are well described by the magnetism theory of singlets at 4.2 K ≤ T ≤ 30 K. The magnetoelectric effect in SMO, GMO and TMO, the anisotropy of magnetoelectric effect in TMO at T = (1.8–4.2 K, the Zeeman effect in TMO, the inversion of the electric polarization induced by the laser beam are discussed. The correlation between the magnetic moment of rare earth ion and the magnetoelectric effect value is predicted. The giant fluctuations of the acoustic resonance peak intensity near the Curie point are observed.
Benoit Curé
2010-01-01
The magnet worked very well at 3.8 T as expected, despite a technical issue that manifested twice in the cryogenics since June. All the other magnet sub-systems worked without flaw. The issue in the cryogenics was with the cold box: it could be observed that the cold box was getting progressively blocked, due to some residual humidity and air accumulating in the first thermal exchanger and in the adsorber at 65 K. This was later confirmed by the analysis during the regeneration phases. An increase in the temperature difference between the helium inlet and outlet across the heat exchanger and a pressure drop increase on the filter of the adsorber were observed. The consequence was a reduction of the helium flow, first compensated by the automatic opening of the regulation valves. But once they were fully opened, the flow and refrigeration power reduced as a consequence. In such a situation, the liquid helium level in the helium Dewar decreased, eventually causing a ramp down of the magnet current and a field...
B. Curé
MAGNET During the winter shutdown, the magnet subsystems went through a full maintenance. The magnet was successfully warmed up to room temperature beginning of December 2008. The vacuum was broken later on by injecting nitrogen at a pressure just above one atmosphere inside the vacuum tank. This was necessary both to prevent any accidental humidity ingress, and to allow for a modification of the vacuum gauges on the vacuum tank and maintenance of the diffusion pumps. The vacuum gauges had to be changed, because of erratic variations on the measurements, causing spurious alarms. The new type of vacuum gauges has been used in similar conditions on the other LHC experiments and without problems. They are shielded against the stray field. The lubricants of the primary and diffusion pumps have been changed. Several minor modifications were also carried out on the equipment in the service cavern, with the aim to ease the maintenance and to allow possible intervention during operation. Spare sensors have been bough...
B. Curé
2013-01-01
The magnet is fully stopped and at room temperature. The maintenance works and consolidation activities on the magnet sub-systems are progressing. To consolidate the cryogenic installation, two redundant helium compressors will be installed as ‘hot spares’, to avoid the risk of a magnet downtime in case of a major failure of a compressor unit during operation. The screw compressors, their motors, the mechanical couplings and the concrete blocks are already available and stored at P5. The metallic structure used to access the existing compressors in SH5 will be modified to allow the installation of the two redundant ones. The plan is to finish the installation and commissioning of the hot spare compressors before the summer 2014. In the meantime, a bypass on the high-pressure helium piping will be installed for the connection of a helium drier unit later during the Long Shutdown 1, keeping this installation out of the schedule critical path. A proposal is now being prepared for the con...
Benoit Curé.
The magnet operation restarted end of June this year. Quick routine checks of the magnet sub-systems were performed at low current before starting the ramps up to higher field. It appeared clearly that the end of the field ramp down to zero was too long to be compatible with the detector commissioning and operations plans. It was decided to perform an upgrade to keep the ramp down from 3.8T to zero within 4 hours. On July 10th, when a field of 1.5T was reached, small movements were observed in the forward region support table and it was decided to fix this problem before going to higher field. At the end of July the ramps could be resumed. On July 28th, the field was at 3.8T and the summer CRAFT exercise could start. This run in August went smoothly until a general CERN wide power cut took place on August 3rd, due to an insulation fault on the high voltage network outside point 5. It affected the magnet powering electrical circuit, as it caused the opening of the main circuit breakers, resulting in a fast du...
A new online database of nuclear electromagnetic moments
Mertzimekis, Theo J.
2017-09-01
Nuclear electromagnetic (EM) moments, i.e., the magnetic dipole and the electric quadrupole moments, provide important information of nuclear structure. As in other types of experimental data available to the community, measurements of nuclear EM moments have been organized systematically in compilations since the dawn of nuclear science. However, the wealth of recent moments measurements with radioactive beams, as well as earlier existing measurements, lack an online, easy-to-access, systematically organized presence to disseminate information to researchers. In addition, available printed compilations suffer a rather long life cycle, being left behind experimental measurements published in journals or elsewhere. A new, online database (http://magneticmoments.info) focusing on nuclear EM moments has been recently developed to disseminate experimental data to the community. The database includes non-evaluated experimental data of nuclear EM moments, giving strong emphasis on frequent updates (life cycle is 3 months) and direct connection to the sources via DOI and NSR hyperlinks. It has been recently integrated in IAEA LiveChart [1], but can also be found as a standalone webapp [2]. A detailed review of the database features, as well as plans for further development and expansion in the near future is discussed.
A new online database of nuclear electromagnetic moments
Directory of Open Access Journals (Sweden)
Mertzimekis Theo J.
2017-01-01
Full Text Available Nuclear electromagnetic (EM moments, i.e., the magnetic dipole and the electric quadrupole moments, provide important information of nuclear structure. As in other types of experimental data available to the community, measurements of nuclear EM moments have been organized systematically in compilations since the dawn of nuclear science. However, the wealth of recent moments measurements with radioactive beams, as well as earlier existing measurements, lack an online, easy-to-access, systematically organized presence to disseminate information to researchers. In addition, available printed compilations suffer a rather long life cycle, being left behind experimental measurements published in journals or elsewhere. A new, online database (http://magneticmoments.info focusing on nuclear EM moments has been recently developed to disseminate experimental data to the community. The database includes non–evaluated experimental data of nuclear EM moments, giving strong emphasis on frequent updates (life cycle is 3 months and direct connection to the sources via DOI and NSR hyperlinks. It has been recently integrated in IAEA LiveChart [1], but can also be found as a standalone webapp [2]. A detailed review of the database features, as well as plans for further development and expansion in the near future is discussed.
Stochastic Generalized Method of Moments
Yin, Guosheng
2011-08-16
The generalized method of moments (GMM) is a very popular estimation and inference procedure based on moment conditions. When likelihood-based methods are difficult to implement, one can often derive various moment conditions and construct the GMM objective function. However, minimization of the objective function in the GMM may be challenging, especially over a large parameter space. Due to the special structure of the GMM, we propose a new sampling-based algorithm, the stochastic GMM sampler, which replaces the multivariate minimization problem by a series of conditional sampling procedures. We develop the theoretical properties of the proposed iterative Monte Carlo method, and demonstrate its superior performance over other GMM estimation procedures in simulation studies. As an illustration, we apply the stochastic GMM sampler to a Medfly life longevity study. Supplemental materials for the article are available online. © 2011 American Statistical Association.
Characterizing flow fluctuations with moments
Directory of Open Access Journals (Sweden)
Rajeev S. Bhalerao
2015-03-01
Full Text Available We present a complete set of multiparticle correlation observables for ultrarelativistic heavy-ion collisions. These include moments of the distribution of the anisotropic flow in a single harmonic and also mixed moments, which contain the information on correlations between event planes of different harmonics. We explain how all these moments can be measured using just two symmetric subevents separated by a rapidity gap. This presents a multi-pronged probe of the physics of flow fluctuations. For instance, it allows to test the hypothesis that event-plane correlations are generated by non-linear hydrodynamic response. We illustrate the method with simulations of events in A MultiPhase Transport (AMPT model.
Identification and Speed Control of PMDC Motor Using Time Moments
Directory of Open Access Journals (Sweden)
Prasanta SARKAR
2010-08-01
Full Text Available In this paper identification and speed control of Permanent Magnet DC Motor is presented. A combination of output error identification technique and method of time moments is used for identification and speed control. The time constraint is expressed using equality between the time moments of the closed loop system and that of a reference model. The reference model is developed from the classical time, frequency and complex domain specifications which guarantee both stability and performance in a model matching framework. Both the simulation and experimental validation show the usefulness of the proposed work.
Spontaneous Regression of Lumbar Herniated Disc
Directory of Open Access Journals (Sweden)
Chun-Wei Chang
2009-12-01
Full Text Available Intervertebral disc herniation of the lumbar spine is a common disease presenting with low back pain and involving nerve root radiculopathy. Some neurological symptoms in the majority of patients frequently improve after a period of conservative treatment. This has been regarded as the result of a decrease of pressure exerted from the herniated disc on neighboring neurostructures and a gradual regression of inflammation. Recently, with advances in magnetic resonance imaging, many reports have demonstrated that the herniated disc has the potential for spontaneous regression. Regression coincided with the improvement of associated symptoms. However, the exact regression mechanism remains unclear. Here, we present 2 cases of lumbar intervertebral disc herniation with spontaneous regression. We review the literature and discuss the possible mechanisms, the precipitating factors of spontaneous disc regression and the proper timing of surgical intervention.
Method of moments in electromagnetics
Gibson, Walton C
2007-01-01
Responding to the need for a clear, up-to-date introduction to the field, The Method of Moments in Electromagnetics explores surface integral equations in electromagnetics and presents their numerical solution using the method of moments (MOM) technique. It provides the numerical implementation aspects at a nuts-and-bolts level while discussing integral equations and electromagnetic theory at a higher level. The author covers a range of topics in this area, from the initial underpinnings of the MOM to its current applications. He first reviews the frequency-domain electromagnetic theory and t
Textural remanence - A new model of lunar rock magnetism
Brecher, A.
1976-01-01
In reexamining the accumulated magnetic data on lunar rocks, several common patterns of magnetic behavior are recognized. Their joint occurrence strongly suggests a new model of lunar rock magnetism, which is based on partial preferred textural alignment of the spontaneous moments of magnetic grains without requiring the existence of ancient lunar magnetic fields. This magnetic fabric, mimetic to locally oriented petrofabric, gives rise to an apparent 'textural remanent magnetization'. In order to account for the observed intensity of 'stable remanence' in lunar rocks, only a minute fraction (0.001 to 0.00001) of the single-domain iron grains present need be preferentially aligned. Several mechanisms operating on the lunar surface, including shock and diurnal thermal cycling, appear adequate for producing the required type and degree of magnetic alignment in all lunar rock classes. The model is supported by a wide variety of direct and indirect evidence, and its predictions (e.g., regarding anisotropic susceptibility and remanence acquisition) can be experimentally tested.
Quadrupole moments measured by nuclear orientation
International Nuclear Information System (INIS)
Bouchta, H.
1985-01-01
Quadrupole interactions between the nuclei and solids have been studied with the low temperature nuclear orientation technique. The first series of measurements have been effected on the orientation of 195H g m and 197 Hg m , long lived daughter states in the 195 Au and 197 Au decay. The lifetimes of these states are of the same order as the spin-lattice relaxation time. The reorientation of the intermediate states has been taken into account extending the dipole relaxation mechanism to non-equidistant relaxing substates. The experimental nuclear quadrupole moments, thus deduced are slightly different from theoretical estimations. A new high precision method accessible to levels with 100 ns to 1 m lifetimes, the level mixing resonance on oriented nuclei (LMR/ON) has been elaborated in collaboration with LEUVEN university (Belgium). In this technique the nucleus is subject to a non colinear electric plus magnetic combined interaction. The quadrupole interaction of Ag[7/2, = 40 s] isomer with the electric field gradient in zinc has been established to better than 1% observing its level mixing resonances; and also the ratio of electric field gradients of silver in zinc to cadmium. The electric quadrupole moments of 106 Ag m , 107 Ag m and 109 Ag m have been established combining the level mixing resonances with classical low temperature quadrupole alignment measurements. The experimental values are in good agreement with theoretical calculations based on a semi-microscopical model using Yukawa potential [fr
Benoit Curé
The magnet subsystems resumed operation early this spring. The vacuum pumping was restarted mid March, and the cryogenic power plant was restarted on March 30th. Three and a half weeks later, the magnet was at 4.5 K. The vacuum pumping system is performing well. One of the newly installed vacuum gauges had to be replaced at the end of the cool-down phase, as the values indicated were not coherent with the other pressure measurements. The correction had to be implemented quickly to be sure no helium leak could be at the origin of this anomaly. The pressure measurements have been stable and coherent since the change. The cryogenics worked well, and the cool-down went quite smoothly, without any particular difficulty. The automated start of the turbines had to be fine-tuned to get a smooth transition, as it was observed that the cooling power delivered by the turbines was slightly higher than needed, causing the cold box to stop automatically. This had no consequence as the cold box safety system acts to keep ...
B. Curé
During the winter shutdown, the magnet subsystems went through a full maintenance. The magnet was successfully warmed up to room temperature beginning of December 2008. The vacuum was broken later on by injecting nitrogen at a pressure just above one atmosphere inside the vacuum tank. This was necessary both to prevent any accidental humidity ingress, and to allow for a modification of the vacuum gauges on the vacuum tank and maintenance of the diffusion pumps. The vacuum gauges had to be changed, because of erratic variations on the measurements, causing spurious alarms. The new type of vacuum gauges has been used in similar conditions on the other LHC experiments and without problems. They are shielded against the stray field. The lubricants of the primary and diffusion pumps have been changed. Several minor modifications were also carried out on the equipment in the service cavern, with the aim to ease the maintenance and to allow possible intervention during operation. Spare sensors have been bought. Th...
Atomic Quadrupole Moment Measurement Using Dynamic Decoupling.
Shaniv, R; Akerman, N; Ozeri, R
2016-04-08
We present a method that uses dynamic decoupling of a multilevel quantum probe to distinguish small frequency shifts that depend on m_{j}^{2}, where m_{j}^{2} is the angular momentum of level |j⟩ along the quantization axis, from large noisy shifts that are linear in m_{j}, such as those due to magnetic field noise. Using this method we measured the electric-quadrupole moment of the 4D_{5/2} level in ^{88}Sr^{+} to be 2.973_{-0.033}^{+0.026}ea_{0}^{2}. Our measurement improves the uncertainty of this value by an order of magnitude and thus helps mitigate an important systematic uncertainty in ^{88}Sr^{+} based optical atomic clocks and verifies complicated many-body quantum calculations.