Speaker
Description
As part of the IS708 experiment carried out at ISOLDE, safe Coulomb excitation measurements with the Miniball detector were performed to investigate octupole and quadrupole collectivity in neutron rich 144Ba. The data from this experiment also provided the opportunity to study such deformation in a selection of other observed A=144 isobars including stable 144Nd, 144Sm as well as radioactive 144Ce and 144Cs. All of which appearing as isobaric contaminants in the beam, despite efforts to optimise the production of 144Ba. The Miniball germanium array coupled with a double-sided silicon strip detector were employed to measure particle-γ coincidences, allowing precise Doppler corrections to be performed.
Initial analysis has identified the population of a range of low-lying collective states, including some for which there are no previously measured transition strengths, e.g., in 144Nd and 144Ce. Clear peaks are also observed for the (3-→2+) transitions in both 144Nd and 144Sm, meaning a remeasurement of B(E3) values can also be made. Matrix elements will be extracted by performing an analysis of the gamma-ray yields using the GOSIA code. It has also been possible, using the timing structure of the proton impact, to isolate transitions in the odd-odd nucleus of 144Cs and identify low-lying collective states for the first time.
This poster presents the beam composition analysis from the 144Ba experiment and preliminary spectroscopy of the odd-odd nucleus 144Cs.
