Speaker
Hanne Heylen
(KU Leuven (BE))
Description
The region south of $^{68}_{28}$Ni$_{40}$ has attracted much interest due to the sudden onset of deformation observed near $N = 40 $. For a better understanding of the dynamics responsible for this change in nuclear structure, it is desirable to expand the experimental knowledge on how the interplay between single-particle and collective nature evolves as a function of proton and/or neutron number. In this light, the ground state properties of Mn ($Z = 25$) isotopes from $N = 28$ up to $N = 39$ were studied in two collinear laser spectroscopy experiments at ISOLDE. In combination with large-scale shell model calculations, these results illustrate the importance of particle-hole excitations across $N = 40$ and $Z= 28$ for Mn isotopes approaching $N = 40$. In particular, the strong influence of the neutron $\nu d_{5/2}$ orbital on the observed deformation is demonstrated.
In a first campaign, the hyperfine spectra of $^{51,53-64}$Mn were measured using standard bunched-beam collinear laser spectroscopy on atomic manganese. Although the magnetic moments and isotope shifts were extracted with high precision, the quadrupole moment sensitivity was low. Hence, in a follow-up experiment, laser spectroscopy was performed on a more sensitive ionic transition starting from a metastable state. To efficiently enhance the population of this metastable state, optical pumping in the cooler-buncher was successfully applied for the first time at ISOLDE.
Apart from the high-precision quadrupole moments, this second experiment also yielded isotope shifts providing a critical test of the electronic factor calculations which are needed for reliable mean-square charge radii extraction. The measured quadrupole moments and mean-square charge radii give complementary information on the development of deformation and will be the main topic of the talk.
Primary authors
Carla Babcock
(University of Liverpool (GB))
Hanne Heylen
(KU Leuven (BE))
Co-authors
Bernhard Maass
(Institut fur Kernphysik, TU Darmstadt)
Bradley Cheal
(Oliver Lodge Laboratory, Oxford Street, University of Liverpool)
Bruce Marsh
(CERN)
Calvin Wraith
(University of Liverpool)
Christopher Geppert
(Gesellschaft fuer Schwerionen forschung mbH (GSI)-Unknown-Unknow)
Deyan Yordanov
(Max-Planck-Gesellschaft (DE))
Iain Moore
(University of Jyväskylä)
Jasna Papuga
(KU Leuven (BE))
Jonathan Billowes
(University of Manchester (GB))
Kim Kreim
(Max-Planck-Gesellschaft (DE))
Klaus Blaum
(Max-Planck-Gesellschaft (DE))
Liang Xie
(University of Manchester (GB))
Magdalena Kowalska
(CERN)
Mark Bissell
(University of Manchester (GB))
Noertershauser Wilfried
(Institut fur Kernphysik, TU Darmstadt)
Paul Campbell
(University of Manchester)
Rainer Neugart
(Johannes-Gutenberg-Universitaet Mainz)
Ralf Erik Rossel
(Johannes-Gutenberg-Universitaet Mainz (DE))
Rodolfo Sanchez
(GSI Helmholtzzentrum fur Schwerionenforschung GmbH,)
Ronald Fernando Garcia Ruiz
(KU Leuven (BE))
Sebastian Rothe
(CERN)
Silvia Lenzi
Stephan Malbrunot
(CERN)
Wolfgang Geithner
(GSI)
Wouter Gins
(KU Leuven)
Xiaofei Yang
(KU Leuven (BE))
