Magnetic dipole moments of (58)Cu and (59)Cu by in-source laser spectroscopy

Online measurements of the magnetic dipole moments and isotope shifts of Cu58 and Cu59 by the in-source laser spectroscopy method are reported. The results for the magnetic moments are μ (Cu58) =+0.52(8) μN,μ(Cu59) =+1.84(3) μN and for the isotope shifts δν59,65=1.72(22) GHz and δν58,65=1.99(30) GHz in the transition from the 3d104sS21/2 ground state to the 3d104pP21/2 state in Cu I. The magnetic moment of Cu58 is discussed in the context of the strength of the subshell closure at Ni56, additivity rules and large-scale shell model calculations. © 2008 The American Physical Society

Nuclear dipole moment of (71)Cu from online beta-NMR measurements

On-line β-NMR measurements on nuclei oriented at low temperatures of the magnetic dipole moment of Cu71(N=42) are reported, with the result μ(Cu71)=+2.28(1) nuclear magneton (n.m.). The value shows a significant difference from μ(Cu67)=+2.54(2) n.m., revealing asymmetry with respect to N=40. This effect presents a challenge to theoretical interpretation. © 2008 The American Physical Society

First On-line beta-NMR on oriented nuclei: magnetic dipole moments of the (nup(1/2))(-1) 1/2(-) ground state in 67Ni and (pip(3/2))(+1) 3/2(-) ground state in 69Cu

The first fully on-line use of the angular distribution of beta emission in detection of NMR of nuclei oriented at low temperatures is reported. The magnetic moments of the single valence particle, intermediate mass, isotopes 67Ni(nup(-1)(1/2);1/2(-)) and 69Cu(pip(1)(3/2);3/2(-)) are measured to be +0.601(5) andmgr;(N) and +2.84(1) andmgr;(N), respectively, revealing only a small deviation from the neutron p(1/2) single-particle value in the former and a large deviation from the proton p(3/2) single-particle value in the latter. Quantitative interpretation is given in terms of core polarization and meson-exchange currents

β − decay of the neutron-rich isotope 215Pb

This Brief Report reports on the first observation of the β− delayed γ decay of 215Pb, feeding states in 215Bi. The 215Pb beam was produced using resonant laser ionization and mass separated at the ISOLDE-CERN on-line mass separator. This ensured clean identification of theγrays as belonging to the decay of 215Pb or its β-decay daughters. A half-life of 147(12) s was measured for the 215Pb β decay and a level scheme for the daughter nucleus 215Bi is proposed, resulting in an extended systematics of the excited states of the neutron-rich Bi isotopes.status: publishe

Coupling a proton and a neutron to the semidoubly magic nucleus Ni-68: A study of Cu-70 via the beta decay of Ni-70 and Cu-70

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Charge radii and magnetic moments of odd-A 183-189Pb isotopes

Isotope shifts and hyperfine splitting parameters have been measured for the neutron-deficient odd-mass lead isotopes 183–189Pb. The measurement was performed at the ISOLDE (CERN) online mass separator using the in-source resonance ionization spectroscopy technique. The nuclear root mean square charge radii and the electromagnetic moments μ and Q_S have been deduced. They follow the smooth trend of the heavier isotopes and indicate the absence of deformation.status: publishe

Charge radii of odd-A 191–211Po isotopes

Isotope shifts have been measured for the odd-A polonium isotopes 191–211Po and changes in the nuclear mean square charge radii δr2 have been deduced. The measurements were performed at CERN-ISOLDE using the in-source resonance-ionization spectroscopy technique. The combined analysis of these data and our recent results for even-A polonium isotopes indicates an onset of deformation already at 197,198Po, when going away from stability. This is significantly earlier than was suggested by previous theoretical and experimental studies of the polonium isotopes. Moreover and in contrast to the mercury isotopes, where a strong odd–even staggering of the charge radii of the ground states was observed by approaching the neutron mid-shell at N = 104, no such effect is present in polonium down to 191Po. Consequently the charge radii of both isomeric and ground states of the odd-A polonium isotopes follow the same trend as the even-A isotopes.status: publishe

Decay of Tl-185, Hg185m+g, Pb189m+g and energy location of the 13/2(+) isomeric states in Hg-185, Pb-189, Po-193 and Rn-197

The β+/EC decay of 185Tl was studied at the ISOLDE acility, theγ-rays belonging to 185Hg have been identified and a partial low-spin level scheme of 185Hg has been built. The decay of 185m+gHg was studied at the ISOCELE facility. Conversion electron lines of very low-energy transitions were observed for the first time. Electron data have been obtained for four transitions in 185Au and two transitions in 185Hg. From the analysis performed using an internal energy calibration procedure the energy location of the 185mHg has been determined to beEIS = 103.7(4) keV. This EIS value is consistent with that determined independently,EIS = 94(13) keV, using 185m+gHg α-decay data from literature. Newαparticles emitted from 189m+gPb have been detected and their origins determined by in-source laser spectroscopy at the ISOLDE facility.α-γcoincidence results have served to locate the 13/2+ isomeric state of 189Pb at EIS = 40(4) keV. This latterEIS value added to α-decay data from literature have allowed the energy location of the 13/2+ isomeric states of 193Po and 197Rn at 95(7) keV and 194(12) keV, respectively. The nuclear structure of the isomeric and ground states in the nuclei of the threeα-emitter chains starting with 195m+g, 197m+g, 199m+gRn are discussed.status: publishe