# ISOLDE Workshop and Users meeting 2006/2007

Feb 12 – 14, 2007
CERN
Europe/Zurich timezone

## Coulomb Excitation of Neutron-rich Isotopes around A~140

Feb 14, 2007, 10:10 AM
20m
Council Chamber, 503/1-001 (CERN)

### Speaker

Mr Thomas Behrens (Physics Department E12, TU München)

### Description

Recent studies on isotopes around the shell closure at N=82 have shown that despite decreasing excitation energy $E(2^{+}_{1})$ the B(E2;$0^{+}_{1} \rightarrow 2^{+}_{1}$) = B(E2$\uparrow$) values for Te and Sn isotopes above N=82 are lower than expected from a general systematics established as "Grodzins' rule". The aim of the experiment IS411 is to measure the B(E2$\uparrow$) values of neutron-rich even-even nuclei in the mass region of $A\approx140$. As a continuation of our experimental campaigns in 2004 and 2005, where the $2^{+}_{1}\rightarrow0^{+}_{g.s.}$ gamma transitions following Coulomb excitation of $^{122,124}$Cd and $^{138,140,142}$Xe beams have been measured with the gamma detector array MINIBALL, in 2006 we measured the respective transitions in $^{144}$Xe and $^{124,126}$Cd. We show preliminary results on B(E2$\uparrow$) values of $^{144}$Xe and $^{126}$Cd for the first time. Perspectives for future experiments will be discussed. This work was supported by BMBF 06MT238 and RII3-EURONS (506065).

### Primary author

Mr Thomas Behrens (Physics Department E12, TU München)

### Presentation materials

 BehrensIS2007.pdf BehrensIS2007.ppt BehrensIS2007.ppt.pdf BehrensIS2007.ppt.ppt