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in subjects: "Quadrupole Moments"

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Atomic and Nuclear Physics Studies With Accelerators

No Description Available.

Date: December 31, 1972

Creator: Leachman, R. B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Dynamic-angle spinning and double rotation of quadrupolar nuclei

Nuclear magnetic resonance (NMR) spectroscopy of quadrupolar nuclei is complicated by the coupling of the electric quadrupole moment of the nucleus to local variations in the electric field. The quadrupolar interaction is a useful source of information about local molecular structure in solids, but it tends to broaden resonance lines causing crowding and overlap in NMR spectra. Magic- angle spinning, which is routinely used to produce high resolution spectra of spin-{1/2} nuclei like carbon-13 … more

Date: July 1, 1991

Creator: Mueller, K.T. (Lawrence Berkeley Lab., CA (United States) California Univ., Berkeley, CA (United States). Dept. of Chemistry)

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Evolution of nuclear shapes at high spins

The dynamic electric quadrupole (E2) moments are a direct reflection of the collective aspects of the nuclear wave functions. For this, Doppler-shift lifetime measurements have been done utilizing primarily the recoil-distance technique. The nuclei with neutron number N approx. 90 possess many interesting properties. These nuclei have very shallow minima in their potential energy surfaces, and thus, are very susceptible to deformation driving influences. It is the evolution of nuclear shapes as… more

Date: January 1, 1985

Creator: Johnson, N.R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Information on nuclear shapes at high spins from lifetime measurements

Using Doppler shift techniques, lifetimes of high spin states have been measured in a number of nuclei near N-90 in order to get their dynamic electric quadrupole moments, which are a direct reflection of the collective aspects of the nuclear wave functions. The potential energy surfaces of /sup 160/Yb (N = 90) reveal that it is very shallow in the ..gamma.. degree of freedom as well as in epsilon/sub 2/ and thus should be susceptible to deformation driving influences. Quadrupole transition mom… more

Date: January 1, 1985

Creator: Johnson, N.R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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A new symmetry in collective motion

The purity of intrinsic states of nuclei with respect to a proton-neutron boson symmetry (F-spin) is shown to be largely determined by the difference between proton and neutron deformations and not by whether the Hamiltonian is an F-spin scalar. F-spin mixing in the ground state band of {sup 165}Ho is estimated using recent pion single-charge-exchange data. A B(M1) sum rule is derived using F-spin symmetry. 27 refs., 1 fig.

Date: January 1, 1991

Creator: Ginocchio, J.N.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Heavy ion inelastic scattering with a 4. pi. gamma detector

Heavy-ion inelastic scattering with a new technique that uses a 4{pi} {gamma}-ray detector in coincidence with charged particle detectors is applied to {sup 24}Mg(200 MeV) + {sup 208}Pb scattering. In addition to differential cross sections, a complete particle-{gamma} angular correlation is obtained for decay of the 2{sub 1}{sup +} (1.37 MeV) state of {sup 24}Mg. The data are analyzed in coupled-channels. The correlation data proves to be especially sensitive to the static quadrupole moment. 1… more

Date: January 1, 1989

Creator: Gross, E.E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Evolution of nuclear shapes at high spins as determined by lifetime measurements

Lifetime measurements of high spin states are obtained by the Doppler-shift recoil-distance method. Transition quadrupole moments are extracted from these data. Expanding on earlier experimental work, lifetime and moment of inertia measurements were made for /sup 172/W. The data for transition quadrupole moments for the yrast states reveals an unexpected drop at high spin which can be explained by the simultaneous alignment of h/sub 9/2/ protons and i/sub 13/2/ neutrons. This conclusion is supp… more

Date: January 1, 1986

Creator: Johnson, N.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Quadrupole Moments of First Excited States in Si, S, and Ar

Static quadrupole moments of the first excited states of {sup 28}Si, {sup 32}S, and {sup 40}Ar have been measured using the reorientation effect in projectile Coulomb excitation. The results obtained are Q({sup 28}Si,2{sup +}) = +0.11 {+-} 0.05 b, Q({sup 32}S,2{sup +}) = -0.20 {+-} 0.06 b, and Q({sup 40}Ar, 2{sup +}) = +0.01 {+-} 0.04 b.

Date: January 1, 1970

Creator: Nakai, K.; Quebert, J. L.; Stephens, F. S. & Diamond, R. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Approximating conductive ellipsoid inductive responses using static quadrupole moments

Smith and Morrison (2006) developed an approximation for the inductive response of conducting magnetic (permeable) spheroids (e.g., steel spheroids) based on the inductive response of conducting magnetic spheres of related dimensions. Spheroids are axially symmetric objects with elliptical cross-sections along the axis of symmetry and circular cross sections perpendicular to the axis of symmetry. Spheroids are useful as an approximation to the shapes of unexploded ordnance (UXO) for approximati… more

Date: October 1, 2008

Creator: Smith, J. Torquil

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Microscopic Calculations of 240Pu Fission

Hartree-Fock-Bogoliubov calculations have been performed with the Gogny finite-range effective interaction for {sup 240}Pu out to scission, using a new code developed at LLNL. A first set of calculations was performed with constrained quadrupole moment along the path of most probable fission, assuming axial symmetry but allowing for the spontaneous breaking of reflection symmetry of the nucleus. At a quadrupole moment of 345 b, the nucleus was found to spontaneously scission into two fragments.… more

Date: September 11, 2007

Creator: Younes, W & Gogny, D

Item Type: Report

Partner: UNT Libraries Government Documents Department

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The proton-neutron interaction and nuclear collectivity

A review is given of several aspects, and empirical consequences, of the p-n interaction as it relates to the structure, phase transitions and collectivity of medium and heavy nuclei. The N/sub p/N/sub n/ scheme is reviewed as background material while the emphasis centers on a discussion of a related quantity, the P factor, and on the relationship of the integrated strength of the p-n interaction to the empirically observed ''saturation'' of B(E2) values in the mid-shell regions of deformed nu… more

Date: January 1, 1987

Creator: Carsten, R. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Understanding nuclear quadrupole deformations

A simple ansatz that ''Nuclei, not too near closed shells, are as deformed as they can be within a single major shell'' appears to quantitatively reproduce the variations of the quadrupole moments and hence the deformations of nuclei. 6 refs., 3 figs.

Date: January 1, 1989

Creator: Raman, S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Solar oscillations, gravitational multipole field of the sun and the solar neutrino paradox

The visual solar oblateness work and the solar seismological work on the internal rotation of the sun are reviewed and their implications concerning the static gravitational multipole moments of the sun are discussed. The results of this work are quite deviant which is indicative of the complexity encountered and of the necessity for continued studies based on a diverse set of observing techniques. The evidence for phase-locked internal gravity modes of the sun is reviewed and the implications … more

Date: November 4, 1986

Creator: Hill, H.A. & Rosenwald, R.D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Giant resonances excited by heavy-ions

The potential of heavy-ion inelastic scattering as a method for studying giant resonance spectroscopy is investigated and compared to results obtained with the (..cap alpha..,..cap alpha..') reaction. Optical model calculations reveal a strong dependence of the excitation cross sections upon bombarding energy. Differences between the backgrounds encountered in light and heavy hadron scattering experiments are discussed. 35 references.

Date: January 1, 1979

Creator: Sandorfi, A.M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Molecular physics and chemistry applications of quantum Monte Carlo

We discuss recent work with the diffusion quantum Monte Carlo (QMC) method in its application to molecular systems. The formal correspondence of the imaginary time Schroedinger equation to a diffusion equation allows one to calculate quantum mechanical expectation values as Monte Carlo averages over an ensemble of random walks. We report work on atomic and molecular total energies, as well as properties including electron affinities, binding energies, reaction barriers, and moments of the elect… more

Date: September 1, 1985

Creator: Reynolds, P. J.; Barnett, R. N.; Hammond, B. L. & Lester, W. A. Jr.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Systematics of effective charges of proton and neutron bosons

Experimental B(E2; 0{sub 1}{sup +} {r arrow} 2{sub 1}{sup +}) values for 54 even-even nuclei in the range A = 90--200 were used to deduce effective charges of proton, neutron bosons. The results indicate that for deformed nuclei, the ratio e{sub n}/e{sub p} is in general agreement with the schematic Bohr and Mottelson prediction. For vibrational nuclei in the A = 100 and A = 140 regions a very significant enhancement of this ratio is found. 6 refs., 3 figs.

Date: January 1, 1990

Creator: Wolf, A. (Israel Atomic Energy Commission, Beersheba (Israel). Nuclear Research Center-Negev) & Casten, R.F. (Brookhaven National Lab., Upton, NY (USA))

Item Type: Article

Partner: UNT Libraries Government Documents Department

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New results on the spectroscopy and dynamics of fission

The present status of Coulomb fission experiments is discussed. Probabilities for fission induced by the purely electromagnetic interaction between heavy ions are compared for the systems Sm + U, W + U, W + Cm, and W + Th. Experimental results on the moments of inertia, spins, and quadrupole moments of fission isomers are summarized. Data are presented that prove their large deformation and thereby justify their interpretation as shape isomers in the second minimum of a double-humped fission ba… more

Date: January 1, 1980

Creator: Metag, V.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Excitation modes in non-axial nuclei

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

Date: January 1, 1990

Creator: Leviatan, A. & Ginnochio, J.N.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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General quadrupole shapes in the Interacting Boson Model

Characteristic attributes of nuclear quadrupole shapes are investigated within the algebraic framework of the Interacting Boson Model. For each shape the Hamiltonian is resolved into intrinsic and collective parts, normal modes are identified and intrinsic states are constructed and used to estimate transition matrix elements. Special emphasis is paid to new features (e.g. rigid triaxiality and coexisting deformed shapes) that emerge in the presence of the three-body interactions. 27 refs.

Date: January 1, 1990

Creator: Leviatan, A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

First results from the UNISOR collinear laser facility

The hyperfine structure and isotope shifts of /sup 189m, 191m, 193m, 193g/Tl have been measured by means of collinear fast-beam/laser spectroscopy. Deformations for the 9/2/sup -/ isomers are determined to be larger than for the 1/2/sup +/ ground state and increase with decreasing neutron number. Despite different deformations, rotational properties are nearly identical in /sup 185 to 199/Tl. Microscopic theory ascribes this to a systematic balance between changing deformation and neutron pairi… more

Date: 1985~

Creator: Carter, H. K.; Leander, G. A.; Bounds, J. A. & Bingham, C. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Nuclear chemistry project. Progress report, January 1, 1978--December 31, 1978. [Summaries of research activities at Princeton University]

Research on the nuclear chemistry project is summarized including Coulomb capture of negative muons by atoms and molecules, nuclear structure and spectroscopy, and the preparation and use of radioactive targets both to study the internal electric fields acting on the nuclei of foreign atoms introduced in metallic solids by radioactive decay and determination of nuclear moments by optical hyperfine spectroscopy. (JFP)

Date: October 10, 1978

Creator: Naumann, R. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Giant resonance decay

Decay studies of giant multipole resonances are discussed, emphasizing the role of Coulomb excitation with intermediate energy heavy ions, which can provide very large cross sections for both isoscalar and isovector resonances. We discuss measurement of the photon decay of one and two phonon giant resonances, reporting results where available. It is pointed out throughout the presentation that the use of E1 photons as a tag'' provides a means to observe weakly excited resonances that cannot be … more

Date: January 1, 1990

Creator: Beene, J.R. & Bertrand, F.E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Deterioration of the skew quadrupole moment in Tevatron dipoles over time

During the 20 years since it was first commissioned, the Fermilab Tevatron has developed strong coupling between the two transverse degrees of freedom. A circuit of skew quadrupole magnets is used to correct for coupling and, though capable, its required strength has increased since 1983 by more than an order of magnitude. In more recent years changes to the Tevatron for colliding beams operation have altered the skew quadrupole corrector distribution and strong local coupling become evident, o… more

Date: May 1, 2005

Creator: Syphers, M. J. & Harding, D. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

High spin spectroscopy for odd-Z nuclei with A approx 160

Experimental routhians, alignments, band crossing frequencies, and the B(M1)/B(E2) ratios of the N = 90 isotones and several light Lu (N = 90--96) isotopes are summarized and discussed in terms of shape changes. This systematic analysis shows a neutron- and proton-number dependent quadrupole and {gamma} deformations for these light rare earth nuclei. The stability of the nuclear deformation with respect to {beta} and {gamma} is also found to be particle-number dependent. Such particle-number de… more

Date: January 1, 1989

Creator: Yu, C.-H. (Niels Bohr Inst., Copenhagen (Denmark) Tennessee Univ., Knoxville, TN (USA). Dept. of Physics and Astronomy); Gascon, J.; Hagemann, G. B. (Niels Bohr Inst., Copenhagen (Denmark)) & Garrett, J. D. (Niels Bohr Inst., Copenhagen (Denmark) Oak Ridge National Lab., TN (USA))

Item Type: Article

Partner: UNT Libraries Government Documents Department