G. Wannberg

Nuclear Spins and Magnetic Moments of Some Neutron-Rich Rubidium and Cesium Isotopes

The nuclear spins and magnetic moments of some neutron-rich rubidium and cesium isotopes have been measured at the ISOLDE facility, CERN, using on-line atomic-beam magnetic resonance (ABMR) techniques. The following results have been obtained: 89Rb, I = 3/2, μ = 2.38(3) n.m.; 90Rb, I = 0; 90mRb, I = 3, μ = 1.61(2) n.m.; 91Rb, μ = 2.18(3) n.m.; 92Rb, I = 0; 95Rb, I = 5/2; 138Cs, μ = 0.701(7) n.m.; 139Cs, I = 7/2, μ = 2.70(3) n.m.; 140Cs, I = 1, μ = ± 0.134(2) n.m.; 141Cs, I = 7/2, μ = 2.42(3) n.m.; 142Cs, I = 0; 143Cs, I = 3/2; 144Cs, I = 1; and 145Cs, I = 3/2. The errors in the magnetic moments are mainly due to the unknown hyperfine anomaly, for which a 1% uncertainty is adopted relative to the reference nuclides 85Rb and 133Cs. The results obtained are discussed in terms of different models for nuclear structure.

Nuclear spins and magnetic moments of some cesium isotopes

Using an atomic-beam magnetic resonance apparatus connected on-line with the ISOLDE isotope separator, CERN, hyperfine structure measurements have been performed in the 2S12 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 120, 121, 121m, 122, 122m, 123, 124, 126, 128, 130m, 135mCs, the isomer of 121Cs being discovered in this work, and magnetic moments of 121, 122, 123, 124, 126, 128, 130, 130mCs are reported and discussed in terms of different nuclear models. The experimental data indicate deformed nuclear shapes of the lightest cesium isotopes.

Nuclear ground-state spin of185Au and magnetic moments of 187, 188Au: Further evidence for coexisting nuclear shapes in this mass region

Abstract Hyperfine structure measurements have been performed in some neutron-deficient gold isotopes, using on-line atomic-beam magnetic resonance (ABMR) techniques at the ISOLDE facility, CERN. The following results have been obtained: 185 Au, I = 5 2 ; 187 Au, Δ v = 44.35(60) GHz, μ = 0.72(7) n.m. and 188 Au, Δ v = ± 2992(30) MHz. A discussion of the influence of the hyperfine anomaly is included. With due regard to this effect, the magnetic moments of 188 Au may be given as μ = ± 0.07(3) n.m. The experimental data are compared with the results from calculations based on the particle-asymmetric rotor model. Strong evidence for coexisting nuclear shapes in 185 Au and for a much larger ground-state deformation in 185 Au than in 187 Au is presented.

Nuclear spins and magnetic moments of some neutron-deficient rubidium isotopes

Abstract The nuclear spins and magnetic moments of some neutron-deficient rubidium isotopes have been measured by atomic-beam magnetic resonance techniques at the ISOLDE facility, CERN. The following results have been obtained: 77 Rb, I = 3 2 , μ I = 0.652(7) n.m. ; 78 Rb, I = 0; 78m Rb,I = 4, μ I = 2.56(3)(rmn.m.); (su79) Rb , I = 5 2 , ifμ I = 3.364(4) n.m. , and 84 m Rb , I = 6 .The data on the The data on the light rubidium isotopes gives evidence for deformed nuclear shapes

Nuclear Ground State Spins of the Francium Isotopes 208-213, 220-222Fr

The nuclear ground state spins of some francium isotopes have been measured using on-line atomic-beam magnetic resonance techniques. The following results have been obtained: 208Fr I = 7, 209Fr I = 9/2, 210Fr I = 6, 211Fr I = 9/2, 212Fr I = 5, 213Fr I = 9/2, 220Fr I = 1, 221Fr I = 5/2 and 222Fr I = 2. The spin values are discussed briefly in terms of current nuclear models.

An atomic-beam magnetic resonance (ABMR) system for on-line hyperfine structure measurements in short-lived nuclides

Abstract In order to reach short-lived nuclides far from stability for hyperfine structure investigations, the atomic-beam apparatus formerly at Uppsala has been reconstructed and connected on-line with the ISOLDE isotope separator at CERN. The design and performance of the system will be described with emphasis laid on the on-line oven section and the automic detection and control systems.

Atomic-beam investigations of some antimony nucleides

Abstract The nuclear spins of some antimony isotopes and the hyperfine structure constants of 117 Sb have been measured by the atomic-beam magnetic resonance method. The results are 116 Sb (16min) I = 3, 116 m Sb (60.4 min )I = 8, 118 m Sb (5.0 h ) I = 8, 120 m Sb (5.76 d ) I = 8, 128 Sb (9.0 h ) I = 8 and 117 Sb (2.8 h ) a = −305(5) MHz , b = 3(21) MHz . The corresponding nuclear moments of 117 Sb , μ I = 3.43(6) n.m. and Q = 0.2(1.2) b, have been evaluated through a direct comparison with known values in the stable nucleus 121 Sb. The magnetic dipole moment which deviates from an earlier measurement, is in good agreement with theoretical predictions.

Nuclear Spins of 165Lu, 168mLu and 172Lu

The nuclear spins of some neutron-deficient lutetium isotopes have been measured using the atomic-beam magnetic resonance method. The following results have been obtained: 165Lu (12 min) I = 1/2, 168mLu (6.7 min) I = 3 and 172Lu (6.7 d) I = 4. The spin values are discussed within the framework of the Nilsson model.

Nuclear Spins of165Lu,168mLu and172Lu

The nuclear spins of some neutron-deficient lutetium isotopes have been measured using the atomic-beam magnetic resonance method. The following results have been obtained: 165Lu (12 min) I = 1/2, 168mLu (6.7 min) I = 3 and 172Lu (6.7 d) I = 4. The spin values are discussed within the framework of the Nilsson model.

NUCLEAR SPINS OF LU-165, LU-168M AND LU-172

The nuclear spins of some neutron-deficient lutetium isotopes have been measured using the atomic-beam magnetic resonance method. The following results have been obtained: 165Lu (12 min) I = 1/2, 168mLu (6.7 min) I = 3 and 172Lu (6.7 d) I = 4. The spin values are discussed within the framework of the Nilsson model.