Speaker
Description
Absolute transition strengths between excited states yield fundamental information on nuclear structure. These observables can be determined from level lifetimes. The recoil distance Doppler-shift (RDDS) technique employing so-called plunger devices provides a valuable method for the determination of lifetimes in the picosecond range and has been in the focus of our Cologne group since many years.
In this talk, we will present the first experimental campaign with the RDDS technique at ISOLDE using the MINIBALL spectrometer. Particular emphasis will be paid to the special conditions for such experiments at this radioactive beam facility, e.g., with respect to the sophisticated plunger device which was constructed at Cologne and is needed for such RDDS experiments, the kinematics, the requirements for targets, and the separation of the reaction channel of interest. We will focus on an experiment on $^{144}$Ba that was done recently by our group aiming for (i) the implementation of the RDDS technique at ISOLDE and (ii) the search for octupole correlations in $^{144}$Ba.