Search results for "isotope shift"
showing 7 items of 17 documents
Charge radii of odd-A 191–211Po isotopes
2013
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 observ…
Laser spectroscopy for nuclear structure physics
2016
High-resolution laser spectroscopy is an established powerful tool in the study of nuclear shape, size and multipole moments. Measurements of the hyperfine structures and isotope shifts in the atomic spectra of radioactive nuclei provide unique insight into the evolution of the nuclear macroscopic shape and microscopic structure. These measurements can be made with high precision and high sensitivity and applied directly on-line at radioactive nuclear beam facilities. Recent measurements, advances at facilities and the future direction of the field are reviewed. A summary of experimental data is presented. peerReviewed
Ground state properties of manganese isotopes across the N=28 shell closure
2010
Abstract The first optical study of the N = 28 shell closure in manganese is reported. Mean-square charge radii and quadrupole moments, obtained for ground and isomeric states in 50–56 Mn, are extracted using new calculations of atomic factors. The charge radii show a well defined shell closure at the magic number. The behaviour of the charge radii is strikingly different to that of the neutron separation energies where no shell effect can be observed. The nuclear parameters can be successfully described by large scale shell model calculations using the GXPF1A interaction.
Nuclear charge radii of molybdenum fission fragments
2009
Abstract Radioisotopes of molybdenum have been studied using laser spectroscopy techniques at the IGISOL facility, University of Jyvaskyla. Differences in nuclear charge radii have been determined for neutron deficient isotopes 90,91Mo and neutron rich isotopes 102–106,108Mo (and all stable isotopes). A smooth transition in the mean square charge radii is observed as the neutron number increases with no sudden shape change observed in the region around N = 60 . As N increases, the nuclear deformation appears to go beyond a maximum and a fall off at N = 66 is observed. The magnetic moments of the odd isotopes 91,103,105Mo are also determined.
Laser spectroscopy of francium isotopes at the borders of the region of reflection asymmetry
2014
The magnetic dipole moments and changes in mean-square charge radii of the neutron-rich $^{218m,219,229,231}\text{Fr}$ isotopes were measured with the newly-installed Collinear Resonance Ionization Spectroscopy (CRIS) beam line at ISOLDE, CERN, probing the $7s~^{2}S_{1/2}$ to $8p~^{2}P_{3/2}$ atomic transition. The $\delta\langle r^{2}\rangle^{A,221}$ values for $^{218m,219}\text{Fr}$ and $^{229,231}\text{Fr}$ follow the observed increasing slope of the charge radii beyond $N~=~126$. The charge radii odd-even staggering in this neutron-rich region is discussed, showing that $^{220}\text{Fr}$ has a weakly inverted odd-even staggering while $^{228}\text{Fr}$ has normal staggering. This sugges…
High-resolution laser system for the S3-Low Energy Branch
2022
International audience; In this paper we present the first high-resolution laser spectroscopy results obtained at the GISELE laser laboratory of the GANIL-SPIRAL2 facility, in preparation for the first experiments with the S$^3$-Low Energy Branch. Studies of neutron-deficient radioactive isotopes of erbium and tin represent the first physics cases to be studied at S$^3$. The measured isotope-shift and hyperfine structure data are presented for stable isotopes of these elements. The erbium isotopes were studied using the $4f^{12}6s^2$$^3H_6 \rightarrow 4f^{12}(^3 H)6s6p$$J = 5$ atomic transition (415 nm) and the tin isotopes were studied by the $5s^25p^2 (^3P_0) \rightarrow 5s^25p6s (^3P_1)$…
High-precision mass measurement of $^{168}$Yb for verification of nonlinear isotope shift
2020
The absolute mass value of $^{168}$Yb has been directly determined with the JYFLTRAP Penning trap mass spectrometer at the Ion Guide Isotope Separator On-Line (IGISOL) facility. A more precise value of the mass of $^{168}$Yb is needed to extract possible signatures of beyond standard model physics from high-precision isotope shift measurements of Yb atomic transition frequencies. The measured mass-excess value, ME($^{168}$Yb) = $-$61579.846(94) keV, is 12 times more precise and deviates from the Atomic Mass Evaluation 2016 value by 1.7$\sigma$. The impact on precision isotope shift studies of the stable Yb isotopes is discussed.