Abstract
The shell model is the most reliable tool for predicting the nuclear properties of
nuclei near closed shells. One of the most important inputs in the shell model is the
matrix elements corresponding to the nucleon-nucleon interactions. These matrix
elements can be modified phenomenologically to reproduce experimentally observed
excited states. Thus, a library of excited states in the interactions model space can
be used to verify and adjust said interaction. This thesis looks to study a
difficult-to-reach and sparsely investigated quadrant of the nuclear chart, ’South’ and
’South-east’ of doubly magic ¹³²Sn. Prompt and near-prompt gamma-ray transitions
emitted from these neutron-rich nuclei were produced at the RIBF in RIKEN,
Japan. A high energy primary ²³⁸U beam was impinged on a 5 mm ⁹Be primary
target to induce in-flight fission. The resulting radioactive cocktail beam was then
separated and identified using the BigRIPS spectrometer. The settings optimised the
transmission of ¹³⁰Cd. This secondary beam was directed onto a secondary target of
Be with a thickness of 6 mm. This target was intended to induce nucleon knockout
reactions of the secondary beam. The residues of these reactions were separated and
identified using the ZeroDegree spectrometer. A new detection system, HiCARI,
consisting of 41 HPGe crystals, was deployed at the secondary target to observe
prompt gamma rays in flight. This was the first case of using HPGe detectors for
in-flight measurements at the RIBF. A line shape analysis method utilising a χ 2
minimisation technique, energies, relative intensities and effective half-lives of excited
states were extracted for key nuclei such as ¹³⁰Cd,¹²⁹Ag and ¹³²In which is a
single proton hole, single neutron particle nucleus. This nucleus ideal for studying the
effective interaction in this part of the nuclear chart. A combination of shell model
iiand reaction theory calculations were used to determine suitable level schemes of
nuclei, of which very little to no excited states were known. Excited states
determined here were used to examine the performance of the proton-proton and
proton-neutron interactions in the framework of the shell model. Not only this, but
nuclear structure data in this area, alongside shell model calculations, can contribute
to understanding the r-process pathway, which has a significant amount of
contributing nuclei in this quadrant.