| dc.description.abstract | The progressive development of scintillator detectors has made it possible to perform direct electronic lifetime determination up to a few hundred nanoseconds. The 2” by 2” LaBr3:Ce detectors
provide a combination of excellent time resolution and good energy resolution. Recently a fast
timing array has been commissioned at iThemba LABS, Cape Town consisting of eight 2” by 2”
LaBr3:Ce detectors. Test measurements using radioactive sources produced at the laboratory were
conducted. Six 2” by 2” LaBr3:Ce detectors were coupled to the AFRODITE array as their first
in-beam experiment. AFRODITE consisted of eight HPGe clover detectors as well as two 3.5” x
8” LaBr3:Ce detectors. A particle telescope was used to select the desired reaction channels. The
reactions of interest 45Sc(p,d)44Sc and 45Sc(p,α)
42Ca were carried out at a beam energy of 27 MeV.
The current analysis also investigates the rare earth nucleus 150Gd which was populated through
150Sm(α,4n)150Gd at a beam energy of 48 MeV. Through these reactions, excited states that have
lifetimes which are apt for the characterization of the 2” by 2” LaBr3:Ce detectors were populated.
Various techniques such as the slope method and the centroid shift method have been employed
to extract the lifetimes of excited states. Lifetimes that were previously measured for 44Sc and
42Ca were measured again in this work. New lifetimes were obtained 44Sc and 150Gd. Shell Model
calculation were done to compare experimental and theoretical results. All these endeavours will
seek to unveil the quadrupole moment of nuclei and their intrinsic behaviour. | en_US |
