Paddy specialises in using gamma-ray and charged-particle spectroscopic techniques to study exotic forms of nuclear matter, with particular emphasis on unusual proton to neutron ratios; the behaviour of nuclei at large angular momentum and the determination of gamma ray transition strengths which can be used to test the best current models of the internal structure of the atomic nucleus.

This includes work at large scale international accelerator facilities such as GSI-FAIR (Germany) and RIBF-RIKEN (Japan) using secondary radioactive ion-beams produced following high-energy projectile fragmentation and projectile fission reactions to study decays of very exotic nuclear species. These studies focus on understanding the formation of heavy elements in explosive astrophysical scenarios (see e.g., https://doi.org/10.1103/PhysRevLett.118.072701 ) and the underlying reasons why some atomic nuclei have non-spherical, prolate deformed shape configurations (see e.g., https://doi.org/10.1016/j.physletb.2016.09.058 ; https://doi.org/10.1103/PhysRevLett.113.262502).

His expertise is in the design and operation of multi-detection gamma-ray detection spectrometers using both semiconductor (Germanium and Silicon) based and halide-scintillator (specifically Lanthanum-Tribromide) based materials (see https://doi.org/10.1016/j.nima.2014.02.037 ). Such spectrometers allow precision measurements of nuclear structure and their characteristic decay properties using gamma-ray coincidence techniques, with their associated digital counting systems routinely able to detect coincident events occurring with less than 1 billionth of a second (i.e. 1 nanosecond) time difference (see e.g., https://doi.org/10.1103/PhysRevC.91.027302 ; https://doi.org/10.1103/PhysRevC.87.014323 ). This work has additional potential applications in both medical (radiopharmaceutical) and long-term civilian nuclear waste management quantitative imaging.