0000000000309057
AUTHOR
P. Vingerhoets
Nuclear mean-square charge radii of63,64,66,68−82Ga nuclei: No anomalous behavior atN=32
Collinear laser spectroscopy was performed on the ${}^{63,64,66,68\ensuremath{-}82}$Ga isotopes with neutron numbers from $N=32$ to $N=51$. These measurements were carried out at the ISOLDE radioactive ion beam facility at CERN. Here we present the nuclear mean-square charge radii extracted from the isotope shifts and, for the lighter isotopes, new spin and moment values. New ground-state nuclear spin and moments were extracted from the hyperfine spectra of ${}^{63,70}$Ga, measured on an atomic transition in the neutral atom. The ground-state spin of ${}^{63}$Ga is determined to be $I=3/2$. Analysis of the trend in the change in mean-square charge radii of the gallium isotopes demonstrates …
An ion cooler-buncher for high-sensitivity collinear laser spectroscopy at ISOLDE
International audience; A gas-filled segmented linear Paul trap has been installed at the focal plane of the high-resolution separator (HRS) at CERN-ISOLDE. As well as providing beams with a reduced transverse emittance, this device is also able to accumulate the ions and release the sample in bunches with a well-defined time structure. This has recently permitted collinear laser spectroscopy with stable and radioactive bunched beams to be demonstrated at ISOLDE. Surface-ionized 39, 44, 46K and 85Rb beams were accelerated to 30keV, mass separated and injected into the trap for subsequent extraction and delivery to the laser setup. The ions were neutralized in a charge exchange cell and exci…
Nuclear Spins and Magnetic Moments ofCu71,73,75: Inversion ofπ2p3/2andπ1f5/2Levels inCu75
We report the first confirmation of the predicted inversion between the pi2p3/2 and pi1f5/2 nuclear states in the nu(g)9/2 midshell. This was achieved at the ISOLDE facility, by using a combination of in-source laser spectroscopy and collinear laser spectroscopy on the ground states of 71,73,75Cu, which measured the nuclear spin and magnetic moments. The obtained values are mu(71Cu)=+2.2747(8)mu(N), mu(73Cu)=+1.7426(8)mu(N), and mu(75Cu)=+1.0062(13)mu(N) corresponding to spins I=3/2 for 71,73Cu and I=5/2 for 75Cu. The results are in fair agreement with large-scale shell-model calculations.
Ground-state spins and moments of72,74,76,78Ga nuclei
Laser spectroscopy was performed on the ${}^{72,74,76,78}$Ga isotopes at On-Line Isotope Mass Separator (ISOLDE) facility, CERN. Ground-state nuclear spins and moments were extracted from the measured hyperfine spectra. The results are compared to shell-model calculations, which provide a detailed probe of the nuclear wave function. The spin is established from the shape of the hyperfine structure and the parity inferred from a comparison of shell-model calculations with the measured nuclear moments. The ground states of ${}^{76,78}$Ga are both assigned a spin and parity of ${I}^{\ensuremath{\pi}}={2}^{\ensuremath{-}}$, while ${}^{74}$Ga is tentatively assigned as ${I}^{\ensuremath{\pi}}={3…
Magnetic and quadrupole moments of neutron deficient 58-62Cu isotopes
Abstract This paper reports on the ground state nuclear moments measured in 58–62Cu using collinear laser spectroscopy at the ISOLDE facility. The quadrupole moments for 58–60Cu have been measured for the first time as Q ( Cu 58 ) = − 15 ( 3 ) efm 2 , Q ( Cu 59 ) = − 19.3 ( 19 ) efm 2 , Q ( Cu 60 ) = + 11.6 ( 12 ) efm 2 and with higher precision for 61,62Cu as Q ( Cu 61 ) = − 21.1 ( 10 ) efm 2 , Q ( Cu 62 ) = − 2.2 ( 4 ) efm 2 . The magnetic moments of 58,59Cu are measured with a higher precision as μ ( Cu 58 ) = + 0.570 ( 2 ) μ N and μ ( Cu 59 ) = + 1.8910 ( 9 ) μ N . The experimental nuclear moments are compared to large-scale shell-model calculations with the GXPF1 and GXPF1A effective i…
Experimental determination of anIπ=2−ground state inCu72,74
This article reports on the ground-state spin and moments measured in $^{72,74}\mathrm{Cu}$ using collinear laser spectroscopy at the CERN On-Line Isotope Mass Separator (ISOLDE) facility. From the measured hyperfine coefficients, the nuclear observables $\ensuremath{\mu}$(${}^{72}\mathrm{Cu})=\ensuremath{-}1.3472(10){\ensuremath{\mu}}_{N}$, $\ensuremath{\mu}({}^{74}\mathrm{Cu})=\ensuremath{-}1.068(3){\ensuremath{\mu}}_{N}$, $Q({}^{72}\mathrm{Cu})=+8(2) {\mathrm{efm}}^{2}$, $Q({}^{74}\mathrm{Cu})=+26(3) {\mathrm{efm}}^{2}$, $I({}^{72}\mathrm{Cu})=2$, and $I({}^{74}\mathrm{Cu})=2$ have been determined. Through a comparison of the measured magnetic moments with different models, the negative …
Discovery of a long-lived low-lying isomeric state in Ga-80
Collinear laser spectroscopy was performed on the $^{80}\mathrm{Ga}$ isotope at ISOLDE, CERN. A low-lying isomeric state with a half-life much greater than $200$ ms was discovered. The nuclear spins and moments of the ground and isomeric states and the isomer shift are discussed. Probable spins and parities are assigned to both long-lived states (${3}^{\ensuremath{-}}$ and ${6}^{\ensuremath{-}}$) deduced from a comparison of the measured moments to shell-model calculations.
Cu charge radii reveal a weak sub-shell effect at N=40
Collinear laser spectroscopy on Cu58-75 isotopes was performed at the CERN-ISOLDE radioactive ion beam facility. In this paper we report on the isotope shifts obtained from these measurements. State-of-the-art atomic physics calculations have been undertaken in order to determine the changes in mean-square charge radii δ(r2)A,A′ from the observed isotope shifts. A local minimum is observed in these radii differences at N=40, providing evidence for a weak N=40 sub-shell effect. However, comparison of δ(r2)A,A′ with a droplet model prediction including static deformation deduced from the spectroscopic quadrupole moments, points to the persistence of correlations at N=40.
Nuclear Charge Radii ofMg21−32
Charge radii of all magnesium isotopes in the sd shell have been measured, revealing evolution of the nuclear shape throughout two prominent regions of assumed deformation centered on (24)Mg and (32)Mg. A striking correspondence is found between the nuclear charge radius and the neutron shell structure. The importance of cluster configurations towards N=8 and collectivity near N=20 is discussed in the framework of the fermionic molecular dynamics model. These essential results have been made possible by the first application of laser-induced nuclear orientation for isotope shift measurements.
Nuclear mean-square charge radii of $^{63,64,66,68−82}$Ga nuclei: No anomalous behavior at N=32
Collinear laser spectroscopy was performed on the 63,64,66,68−82Ga isotopes with neutron numbers from N = 32 to N = 51. These measurements were carried out at the ISOLDE radioactive ion beam facility at CERN. Here we present the nuclear mean-square charge radii extracted from the isotope shifts and, for the lighter isotopes, new spin and moment values. New ground-state nuclear spin and moments were extracted from the hyperfine spectra of 63,70Ga, measured on an atomic transition in the neutral atom. The ground-state spin of 63Ga is determined to be I = 3/2. Analysis of the trend in the change in mean-square charge radii of the gallium isotopes demonstrates that there is no evidence of anoma…
Nuclear spins, magnetic moments, and quadrupole moments of Cu isotopes fromN=28toN=46: Probes for core polarization effects
Measurements of the ground-state nuclear spins and magnetic and quadrupole moments of the copper isotopes from $^{61}\mathrm{Cu}$ up to $^{75}\mathrm{Cu}$ are reported. The experiments were performed at the CERN online isotope mass separator (ISOLDE) facility, using the technique of collinear laser spectroscopy. The trend in the magnetic moments between the $N=28$ and $N=50$ shell closures is reasonably reproduced by large-scale shell-model calculations starting from a $^{56}\mathrm{Ni}$ core. The quadrupole moments reveal a strong polarization of the underlying Ni core when the neutron shell is opened, which is, however, strongly reduced at $N=40$ due to the parity change between the $\mat…
Spin and magnetic moment of23Mg
A negative magnetic moment of 23Mg has been determined by collinear laser spectroscopy at CERN-ISOLDE. The absolute value is in agreement with previous measurements by nuclear magnetic resonance while the sign points at high-seniority configurations. The result is consistent with shell-model predictions for nuclei with valence nucleons in the sd shell. ispartof: Journal of Physics G, Nuclear and Particle Physics vol:44 issue:7 status: published
Laser spectroscopy of gallium isotopes beyond N = 50
The installation of an ion-beam cooler-buncher at the ISOLDE, CERN facility has provided increased sensitivity for collinear laser spectroscopy experiments. A migration of single-particle states in gallium and in copper isotopes has been investigated through extensive measurements of ground state and isomeric state hyperfine structures. Lying beyond the N = 50 shell closure, 82Ga is the most exotic nucleus in the region to have been studied by optical methods, and is reported here for the first time. ispartof: pages:012071-6 ispartof: Journal of Physics: Conference Series vol:381 issue:1 pages:012071-6 ispartof: Rutherford Centennial Conference on Nuclear Physics location:Manchester, UK dat…