Search results for "Quadrupole"
showing 10 items of 460 documents
Collinear laser spectroscopy on108g, 108m In using an ion source with bunched beam release
1986
The hyperfine structure and isotope shift of108gIn and108mIn have been investigated by means of collinear fast-beam laser spectroscopy in the resonance line atλ=451 nm. The indium isotopes were prepared at the GSI on-line mass separator following a fusion evaporation reaction. For the first time, a FEBIAD ion source with bunched release of indium was used. Magnetic dipole moments, electric quadrupole moments and isotope shifts were determined. The present results lead us to assign the spinI=2 to the108In (T 1/2=40 min) state. Spins and moments are discussed in the framework of thejj-coupling model.
A direct determination of the proton-electron mass ratio
1978
The cyclotron resonance of protons and electrons in a magnetic field of 5.7 Tesla produced by a superconducting solenoid has been measured. Protons and electrons were alternately confined in an electrostatic quadrupole trap. The quotient of the cyclotron frequencies provides a first direct determination of the proton-electron mass ratio. The result ofM p /M e =1836.1502(53) agrees with other more precise but indirect determinations of this quantity.
Ground-state electromagnetic moments of calcium isotopes
2015
Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAM
Nuclear moments and charge radii of argon isotopes between the neutron-shell closures and
2008
We report the measurement of optical isotope shifts for 40−44 Ar relative to 38 Ar from which changes in the mean square nuclear charge radii across the 1f7/2 neutron shell are deduced. In addition, the hyperfine structure of 41 Ar and 43 Ar yields the spins, magnetic dipole and electric quadrupole moments, in particular the spin I = 5/2 for 43 Ar. The investigations were carried out by fast-beam collinear laser spectroscopy using highly sensitive detection based on optical pumping and state-selective collisional ionization. Mean square charge radii are now known from 32 Ar to 46 Ar, covering sd-shell as well as f7/2-shell nuclei. They are discussed in the framework of spherical SGII Skyrme…
Elastic electron deuteron scattering with consistent meson exchange and relativistic contributions of leading order
1999
The influence of relativistic contributions to elastic electron deuteron scattering is studied systematically at low and intermediate momentum transfers ($Q^2\leq 30$ fm$^{-2}$). In a $(p/M)$-expansion, all leading order relativistic $\pi$-exchange contributions consistent with the Bonn OBEPQ models are included. In addition, static heavy meson exchange currents including boost terms and lowest order $\rho\pi\gamma$-currents are considered. Sizeable effects from the various relativistic two-body contributions, mainly from $\pi$-exchange, have been found in form factors, structure functions and the tensor polarization $T_{20}$. Furthermore, static properties, viz. magnetic dipole and charge …
Evaluation of the forward Compton scattering off protons: Spin-independent amplitude
2015
We evaluate the forward Compton scattering off the proton, based on Kramers-Kronig kind of relations which express the Compton amplitudes in terms of integrals of total photoabsorption cross sections. We obtain two distinct fits to the world data on the unpolarized total photoabsorption cross section, and evaluate the various spin-independent sum rules using these fits. For the sum of proton electric and magnetic dipole polarizabilities, governed by the Baldin sum rule, we obtain the following average (between the two fits): $\alpha_{E1}+\beta_{M1}=14.0(2)\times 10^{-4}\,\mathrm{fm}^3$. An analogous sum rule involving the quadrupole polarizabilities of the proton is evaluated too. The spin-…
Systematic QRPA study of β− and decay transitions to excited states of 110–114Cd and 114–122Sn
1995
Abstract A systematic study of the β− and β + EC decay transitions of odd-odd nuclei into the ground state, first excited quadrupole state (21+) and the two-quadrupole-phonon triplet (02ph+, 22ph+ and 42ph+) of the final even-even nuclei 110–114Cd and 114–122Sn is performed. In these cases the states of the even-even nucleus are fed both by β− as well as β + EC decay transitions of the two adjacent double-odd nuclei. Such exceptional circumstances help to study the β− and β + EC Gamow-Teller decay on equal footing starting from the predictions of the combined QRPA and pn-QRPA theories. In addition, the differences between the QRPA and the QTDA predictions are discussed. The present approach…
Quadrupole collective inertia in nuclear fission: Cranking approximation
2010
Collective mass tensor derived from the cranking approximation to the adiabatic time-dependent Hartree-Fock-Bogoliubov (ATDHFB) approach is compared with that obtained in the Gaussian Overlap Approximation (GOA) to the generator coordinate method. Illustrative calculations are carried out for one-dimensional quadrupole fission pathways in 256Fm. It is shown that the collective mass exhibits strong variations with the quadrupole collective coordinate. These variations are related to the changes in the intrinsic shell structure. The differences between collective inertia obtained in cranking and perturbative cranking approximations to ATDHFB, and within GOA, are discussed.
Character of an 8− isomer of 130Ba
2002
Abstract The static moments and isomer shift of the J π = K π =8 − isomeric state in 130 56 Ba have been measured using the technique of collinear laser spectroscopy. The isomer has been found to have a magnetic dipole moment of −0.043(28) μ N and a static quadrupole moment of +2.77(30) b. These values have been used to assign the state as a two neutron 7 2 + [404]⊗ 9 2 − [514] configuration corresponding to a prolate shape. The half-life of the isomer has been confirmed as 9.54(14) ms. The change in the mean square charge radius was found to be 〈 r 2 〉 130m −〈 r 2 〉 130g–s =−0.0473(30) fm 2 .
High precision measurement of the11Li and9Li quadrupole moment ratio using zero-fieldβ-NQR
2013
The ratio of electric quadrupole moments of 11 Li and 9 Li was measured using the zero-field β-detected nuclear quadrupole resonance technique at TRIUMFISAC. The precision on the ratio Q11/Q9 = 1.0775(12) was improved by more than one order of magnitude and an absolute value for the quadrupole moment of 11 Li was inferred. Systematic effects, as argued here, are not expected to contribute to the ratio on this scale. The zero-field spin-lattice relaxation time for 8 Li implanted within SrTiO3 at 295K in zero-field was found to be T1 = 1.73(2)s. A comparison of the quadrupole moments of 9,11 Li and their ratio is made with the latest models, however, no conclusion may yet be drawn owing to th…