Speaker
Sarah Naimi
(Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse (CSNSM))
Description
The results of two recent ISOLTRAP experiments are discussed in this contribution.
(1) Sudden offset of deformation around N=60
(or, Reformation of Kr isotopes around N=60)
Whereas canonical nuclear structure decrees a sub-shell closure at
N=56, neutron-rich Zr and Sr istopes are known to exhibit sudden
and intense deformation instead. This deformation, visible from a
deep dent in the mass surface, is interpreted as a nuclear quantum phase transition. It is of interest to determine the conditions where this phase transition (or deformation) begins but also where it ends.
Microscopic mass predictions in the mean-field framework (HFB-17) tells us
that Kr will be strongly deformed as well. However, first mass measurements
of 96,97Kr, using the Penning-trap spectrometer ISOLTRAP, show this not to
be the case.
(2) All quiet on the western N=40 front
(or, Magic-number migration in Mn isotopes)
The many attempts of establishing a shell closure at N=40 have resulted in admitting that the effect depends on whether Z=28 or not. New mass measurements of Mn (Z=25) from ISOLTRAP confirm this observation.
In fact, the strong effect at N=35 visible from previous measurements
is shown to completely disappear. However, a new effect, though more subtle,
does appear in the case of N=34, perhaps indicating the manifestation of a new
magic number.
Author
Sarah Naimi
(Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse (CSNSM))
Co-author
ISOLTRAP Collaboration the
(Heidelberg-Greifswald-CERN-Mainz-GSI-Orsay)
