Münster 2017 – wissenschaftliches Programm
HK 61.6: Vortrag
Freitag, 31. März 2017, 15:15–15:30, F 33
Determination of lifetimes of excited states in fission fragments from 252Cf using LaBr3(Ce) detectors — •Guillermo Fernández Martínez, Stoyanka Ilieva, and Thorsten Kröll for the FATIMA collaboration — Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstr. 9, 64289 Darmstadt
The experimental determination of transition probabilities of excited states in exotic nuclei by direct lifetimes measurements is crucial for the understanding of nuclear structure. The FAst-TIMing Array (FATIMA), that the upcoming FAIR will house, will consist of a set of LaBr3(Ce) detectors, well known for their combination of good energy resolution and very fast response, and will be able to determine very short lifetimes. However, prior to the construction of FATIMA and its final placement at FAIR, some experiments have to be performed. One of these experimental campaigns was carried out at the Argonne National Laboratory, and aimed for the measurement of lifetimes of excited states in the fission products from the spontaneous fission of 252Cf. The FATIMA demonstrator, made out of 25 of the aforementioned LaBr3(Ce) crystals, was used in combination with an array of 55 HPGe detectors from the existing Gammasphere. For the determination of lifetimes in the region from some nanoseconds down to few tens of picoseconds, the generalised centroid difference (GCD) method, that has been already proven to provide reliable results, was used. In the present work, first preliminary results for the first excited states of neutron-rich even-even nuclei are shown.