Nuclear quadrupole moments of radioactive83Rb,84Rb and86Rb

Excited atomic² P _3/2-states of radioactive Rb isotopes have been investigated by level crossing and optical double resonance spectroscopy. The measured hyperfine structure constants yielded the nuclear moments $$\begin{gathered} \mu _I (^{84} Rb) = - 1.296(11)\mu _K Q(^{83} Rb) = + 0.27(5) \cdot 10^{ - 24} cm^2 \hfill \\ Q(^{84} Rb) = + 0.005(13) \cdot 10^{ - 24} cm^2 \hfill \\ Q(^{86} Rb) = + 0.20(3) \cdot 10^{ - 24} cm^2 \hfill \\ \end{gathered} $$ and the hyperfine anomaly₈₄Δ₈₅=+1.7(1.0) · 10^?2. The quadrupole moments of⁸³Rb to⁸⁷Rb can be explained with the unified model of vibrations.     

Spectroscopic nuclear quadrupole moments

A ‘year-2001’ set of nuclear quadrupole moments, Q, is presented. Compared to the previous, ‘year-1992’ set, a major revision of the value or a considerable improvement of the accuracy is reported for ⁶ ₃Li, ₇N, ¹⁹ ₉F (197 keV, I = 5/2), ₁₁Na, ₁₃Al, ₂₁Sc, ₂₂Ti, ₂₆Fe (14 keV, I = 3/2 Mössbauer state), ₃₁Ga, ₃₂Ge, ⁷⁷ ₃₄Se (250 keV, I = 5/2 state), ₃₅Br, ₃₆Kr, ₃₇Rb, ₃₉Y, ₄₀Zr, ¹⁰⁰ ₄₅Rh, ₅₀Sn (24 keV, I = Mössbauer state), ₅₃I, ₅₄Xe, ₅₅Cs and ₈₃Bi.     

Year-2017 nuclear quadrupole moments

A ‘year-2017’ set of nuclear quadrupole moments, Q, is presented. Compared to the previous, ‘year-2008’ set, a major revision of the value, or an improvement of the accuracy is reported for ²₁H, ^{37, 39}₁₈Ar, ^{39, 40, 41}₁₉K, ⁶⁷₃₀Zn, ₄₈Cd, ₄₉In, ₅₀Sn (Mössbauer state), ₅₁Sb, ₈₇Fr and ₉₀Th. Slight improvements or valuable reconfirmations exist for ₄Be, ₆C, ₁₆S, ₁₇Cl, ₃₃As, ₃₅Br, ₅₃I, ₅₄Xe, ₅₆Ba, ₅₇La and ₇₂Hf.     

The argon nuclear quadrupole moments

New standard values -116(2) mb and 76(3) mb are suggested for the nuclear quadrupole moments (Q) of the ³⁹Ar and ³⁷Ar nuclei, respectively. The Q values were obtained by combining optical measurements of the quadrupole coupling constant (B or eqQ/h) of the 3s²3p⁵4s[3/2]₂ (³P^o) and 3s²3p⁵4p[5/2]₃ (³D^e) states of argon with large scale numerical complete active space self-consistent field and restricted active space self-consistent field calculations of the electric field gradient at the nucleus (q) using the LUCAS code, which is a finite-element based multiconfiguration Hartree–Fock program for atomic structure calculations.     

Nuclear quadrupole moments of bismuth

Multiconfiguration Dirac-Fock models have been employed to compute the electric field gradient in the ground state of the neutral bismuth atom. Combined with the experimental electric quadrupole hyperfine interaction constant, one obtains for (209)Bi the nuclear quadrupole moment Q = -516 (15) mb, which is almost 40% away from the previously accepted standard value [ -370 (26) mb], and narrows by over an order of magnitude the long-standing, extremely broad array of various results ranging from -370 to -710 mb. The recent Q values of (202-208,210(m)-213)Bi by Pearson et al. suffer a consequent change.     

Impadg-factor measurements in83Y

The IMPAD technique has been used to determine the Larmor precessions of the⁸³Y 595 keV 13/2⁺ and 145 keV 7/2⁺ states in iron. The net precessions found are ωτ(13/2⁺)=−9(2) mrad and ωτ(7/2⁺)=−92(5) mrad, leading to g-factors, g(13/2⁺)=+1.3(4) and g(7/2⁺)=+0.61(18). These results are discussed in terms of a partially decoupled [422]5/2⁺ Nilsson band.     

Systematic description of nuclear electric quadrupole moments

The nuclear electric quadrupole moment(NQM) is one of the fundamental bulk properties of the nucleus with which nuclear deformations can be investigated. The number of measured NQMs is significantly less than that of known masses, and there is still no global NQM formula for all bound nuclei. In this paper, we propose an analytical formula, which includes the shell corrections and which is the function of the charge number, mass number, spin,charge radius, and nuclear deformation, for calculating the NQMs of all bound nuclei. Our calculated NQMs of 524 nuclei in their ground states are reasonable compared to the experimental data based on the nuclear deformation parameters derived from the Weizs¨acker-Skyrme(WS) nuclear mass models. Smaller rms deviations between the calculated NQMs and experimental data indicate that the deformation parameters predicted from the WS mass models are reasonable. In addition, 161 unmeasured NQMs with known spins are also predicted with the proposed formula.     

Electric quadrupole moments of radioactive Pt isotopes

Nuclear orientation experiments were performed on¹⁸⁹Pt (I=3/2^–; T_1/2=11 h),¹⁹¹pt (I=3/2^–; T_1/2=2.8 d) and^195mpt=3/2^–; T_1/2=4.0 d) in an Os single crystal at temperatures down to 10 mK. Preliminary results for the quadrupole splitting _o=e²qQ/h are +48 (9), +39 (6), and –87 (12) MHz for¹⁸⁹ptOs,¹⁹¹ptOs, and¹⁹⁵mptOs, respectively. Preliminary results for the quadrupole moments are –0.8 (4), –0.6 (3), and +1.4 (7) b for¹⁸⁹pt,¹⁹¹pt, and¹⁹⁵mpt, respectively. In addition, the quadrupole subresonance structure of¹⁸⁹pt and¹⁹¹pt in Fe was measured with quadrupole-interaction resolved NMR-ON spectroscopy. The results for the magnetic hyperfine splitting _M=¦g_NB_HF/h¦ and _Q are:¹⁸⁹ptFe: _M=277.9 (1) MHz; _Q=+1.39 (5) MHz.¹⁹¹ptFe: _M=320.17 (3) MHZ; _Q=+1.39 (3) MHz. The ratio of the quadrupole moments of¹⁹¹pt and¹⁸⁹pt is deduced to be Q (¹⁹¹Pt/Q^l89pt)=+1.00 (4). The negative quadrupole moments of¹⁸⁹pt and¹⁹¹pt indicate a predominantly oblate shape of the ground states.     

Spectroscopic quadrupole moments of high-spin isomers in 193 Pb

The quadrupole interaction of high-spin isomers in ¹⁹³Pb implanted into solid Hg cooled at a temperature T = 170 K has been investigated by the time-differential perturbed -ray angular-distribution method. Spectroscopic quadrupole moment values of eb and 0.45(4) eb have been deduced for the 21/2^- and 33/2 ⁺ three-neutron states, respectively. A much higher value eb has been determined for the 29/2^- isomer, the band head of a magnetic rotational band.Received: 4 November 2002, Published online: 2 March 2004PACS: 21.10.Ky Electromagnetic moments - 27.80. + w      

Transition quadrupole moments of superdeformed states in194Pb

Lifetimes of superdeformed states in¹⁹⁴Pb were measured by the Doppler-shift attenuation method. Quadrupole moments around 20 eb, that are constant over the observed frequency range, are derived. The results rule out large centrifugal stretching effects.     

Reorientation precession measurements of quadrupole moments in103Rh

The quadrupole moments of the 3/2^? and 5/2^? states in¹⁰³Rh have been determined by measuring the precession of the gamma-ray angular distribution following Coulomb excitation;¹⁶O and³²S beams have been used. The structure of the negative-parity states in¹⁰³Rh is found to be in agreement with the model of Arima and Iachello.     

Current electric quadrupole moments of atoms and nuclei

It is shown that current electric multipoles exist. Their field is electrostatic and it is unrelated to the existence of a net electric charge. At long range, it is the same as the field of the corresponding charge electric multipoles. Current electric multipoles arise during the motion of magnetic multipoles. An orbital motion of magnetic dipoles, a precession of a current-carrying loop, and the motion of magnetic quadrupoles all lead to current electric quadrupole moments. Expressions for the current electric quadrupole moments of atoms and nuclei are derived.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 53–58, July, 1991.The author wishes to thank S. A. Kuten' and V. I. Rapoport for useful comments offered during the writing of this paper and for a discussion of the results.     

Static electric quadrupole and hexadecapole moments of nuclei

Ground-state static electric quadrupole and hexadecapole moments of even nuclei are calculated microscopically. Rare-earth, actinide and neutron-deficient nuclei with 50 <Z, N < 82 and neutron-rich nuclei with 28 < Z < 50, 50 < N < 82 are studied. Fairly good agreement with experiment is found. In the actinide region, the electric moments of fission isomers are also examined.     

Magnetic dipole moments of collective quadrupole excited states

Magnetic dipole moments for low-lying collective quadrupole excitations are studied in heavy and medium-heavy nuclei within the framework of the Interacting Boson Model (IBM-2). In the present study, we concentrate mainly on the fully symmetric representations of the U(6) group and their magnetic dipole moments. We shortly discuss the lowest non-symmetric 1⁺ level. Comparison with other collective model calculations of g_R and microscopic studies as well as with experimental data is performed.The authors are most grateful to A.E.L.Dieperink and coworkers for the generous help and permission to quote largely from their recent results on magnetic dipole moments in nuclei.They are also indebted to A.Richter,O.Scholten and Iachello for many stimulating discussions. They thank the NFWO,IIKW and the IWONL for financial support.     

Relation between electric quadrupole and magnetic dipole nuclear moments

The values of electric quadrupole moments are described by gyromagnetic ratios of bound and free nucleons. A comparison with the experimental data shows an agreement within 15% for non-magic strongly deformed nuclei and within 50% for other ones. The expressions obtained are sensitive to a change in the order of subshell filling which takes place for proton and neutron subshells near Fermi surface.     

Precision measurements of nuclear quadrupole moments by muonic X-rays

The electric multipole hyperfine interaction in muonic atoms is discussed. In particular, the influence of the finite size of the nuclear electric multipole-charge distribution on the values of nuclear spectroscopic multipole moments that are extracted from muonic hyperfine measurements is considered. It is shown that nuclear electric quadrupole moments can be deduced from the observed hyperfine splittings of muonic M X-ray transitions with high precision and practically independently of the model nuclear quadrupole-charge density. Measurements of the ground-state electric quadrupole moments of 11 deformed nuclei in and near the rare-earth region are discussed.