Speaker
Magda Zielinska
(CEA Saclay)
Description
A low-energy Coulomb excitation experiment on neutron-rich 44Ar has been performed
at the SPIRAL facility of GANIL. The primary question addressed by the experiment was
the possible weakening of the N=28 shell closure in neutron-rich nuclei and, closely
connected to that, the development of deformation and shape coexistence in this
region of the nuclear chart. A beam of 44Ar was produced by fragmentation of a
primary 48Ca beam at 60 A MeV on the carbon production target of SPIRAL. The Ar44
fragments were re-accelerated in the CIME cyclotron to 2.7 and 3.7 MeV/nucleon and
Coulomb excited on 109Ag and 208Pb targets, respectively. The scattered projectiles
and recoiling target nuclei were detected in a highly segmented double-sided silicon
detector and the gamma rays were detected with the EXOGAM germanium detector array.
Apart from the first excited 2+ state, at least one higher-lying level was populated.
The level of statistics is sufficient to determine the gamma-ray yields for several
ranges of scattering angles and for the two different target materials. Although the
analysis is still in progress, it is anticipated that the collected data will allow
extracting the transition probabilities between the observed states, as well as the
static quadrupole moment of the first 2+ state. It is anticipated to continue in this
experimental program with the Coulomb excitation of 46Ar.
Author
Magda Zielinska
(CEA Saclay)
Co-authors
Alexander Buerger
(University of Bonn)
Andreas Goergen
(CEA Saclay)
Cedric Dossat
(CEA Saclay)
Christophe Theisen
(CEA Saclay)
Daniel Pietak
(Warsaw University of Technology)
Emmanuel Clement
(CERN)
Geirr Sletten
(NBI Copenhagen)
Jedrzej Iwanicki
(HIL Warsaw)
Joa Ljungvall
(CEA Saclay)
Julian Srebrny
(HIL Warsaw)
Katarzyna Wrzosek
(HIL Warsaw)
Pawel J. Napiorkowski
(HIL Warsaw)
Wilton Catford
(University of Surrey)
Wolfram Korten
(CEA Saclay)
