Patrick Regan

Professor Patrick ‘Paddy’ Regan, FInstP, is the first NPL Fellow in Nuclear and Radiation Science and Metrology. He leads NPL’s science in nuclear structure physics, radioactive decay characterisation and radioactivity measurement.  Paddy joined NPL in 2013 as the UK’s first Professor of Nuclear Metrology, joint with the University of Surrey.

He undertook his BSc (Hons) in Physics at the University of Liverpool (1988) and his DPhil in experimental nuclear physics at the University of York (1991), specialising in gamma-ray spectroscopy for investigations of nuclear structure. He then held post-doctoral positions in experimental nuclear physics at the University of Pennsylvania, USA (1991-2) and the Australian National University in Canberra (1992-4). Paddy was appointed to a fixed-term lectureship at the University of Surrey in Physics in 1994, subsequently being promoted to Lecturer (1997), Senior Lecturer (2003), Reader (2005) and Full Professor in 2009. Paddy has also held long-term (2002-2013) visiting research and teaching positions at Yale University and the University of Notre Dame, USA.

Paddy represents NPL on various national and international nuclear science committees, including several UKRI and overseas grant review and laboratory evaluation committees. He is also a former member of the International Union of Pure and Applied Physics (IUPAP) committee on nuclear physics (C12).  He is a Fellow of the Institute of Physics (FInstP, 2000), has co-authored more than 300 peer-reviewed publications and acted as primary supervisor for more than 40 successful doctoral research students in nuclear and radiations science.

Current interests

Paddy is leading work in the production, identification, measurement and evaluation of nuclear decay data and fundamental decay properties of novel radioisotopes.

This work includes validation and construction of nuclear energy level schemes and measurement of very precise nuclear decay data, including sub-nanosecond timescales for some types of decay. His team is involved in leading research into complex data analysis and calibration techniques for nuclear structure science and the related provision of standards and reference materials for applications in the energy, environment and health sectors. Impact from these research contributions crosses over areas including ‘big science questions’ such as understanding the nature of nuclear matter and nucleosynthesis of the elements formed in stellar interiors to direct applications including nuclear forensics; power generation and waste managements; and nuclear medicine.

Recent Selected Publications:

1. Determination of the ¹⁶¹Tb half-life, S.M.Collins et al.  Applied Radiation and Isotopes 182 (2022): 110140 . https://doi.org/10.1016/j.apradiso.2022.110140
    
2. Production and measurement of fission product noble gases M. Goodwin, S. Bell et al., Journal of Environmental Radioactivity, 238 (2021) 106733  https://doi.org/10.1016/j.jenvrad.2021.106733
    
3. Angular Momentum Generation in Nuclear Fission, J. Wilson et al., Nature 590 (7847) p566-570,  published, 25 Feb 2021, https://doi.org/10.1038/s41586-021-03304-w
    
4. Magnetic moment of the 11/2⁻ isomeric state in Mo-99 and neutron spin g-factor quenching in A≈ 100 nuclei. J.M.Daugas et al., Physical Review C 104 (2021): 024321 https://doi.org/10.1103/PhysRevC.104.024321
    
5. Competition between Allowed and First-Forbidden β Decay: The Case of 208Hg→208Tl, R.Carroll et al.,  Physical Review Letters, 125, 192501 https://doi.org/10.1103/PhysRevLett.125.192501
    
6. A high-resolution β−γ coincidence spectrometry system for radioxenon measurements, M.Goodwin et al., Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Volume 978, 21 October 2020, 164452 https://doi.org/10.1016/j.nima.2020.164452
    
7. Advances in the Direct Study of Carbon Burning in Massive Stars G. Fruet et al. Phys. Rev. Lett. 124, 192701 – Published 12 May 2020 https://doi.org/10.1103/PhysRevLett.124.192701
    
8. Half-life measurements in ^164,166Dy using γ−γ fast-timing spectroscopy with the ν-Ball spectrometer R. L. Canavan et al. Phys. Rev. C 101, 024313 – Published 26 February 2020 https://doi.org/10.1103/PhysRevC.101.024313
    
9. FATIMA — FAst TIMing Array for DESPEC at FAIR, M. Rudigier et al, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Volume 969, 21 July 2020, 163967  https://doi.org/10.1016/j.nima.2020.163967
    
10. Observation of a μs isomer in ¹³⁴In: Proton-neutron coupling “southeast” of ¹³²Sn V. H. Phong et al. Phys. Rev. C 100, 011302(R) – Published 29 July 2019 https://doi.org/10.1103/PhysRevC.100.011302 
     
11. Interplay of quasiparticle and vibrational excitations: First observation of isomeric states in ¹⁶⁸Dy and ¹⁶⁹Dy, G.X.Zhang et al., Physics Letters B Volume 799, 10 December 2019, 135036 https://doi.org/10.1016/j.physletb.2019.135036
     
12.  Investigation of g-g coincidence counting using the National Nuclear Array as a Primary Standard: S.Collins, R. Shearman, P.H.Regan & J.D.Keightley, Applied Radiation and Isotopes 134 (2018) p290-296 http://dx.doi.org/10.1016/j.apradiso.2017.07.056c 
     
13. Commissioning of the UK NAtional Nuclear Array, R. Shearman et al., Radiation Physics and Chemistry Volume 140, November 2017, Pages 475-479 https://doi.org/10.1016/j.radphyschem.2017.02.007
     
14. Anomalies in the Charge Yields of Fission Fragments from the 238U(n,f) Reaction, J.Wilson et al., Physical Review Letters 118, 222501 (2017) 
    https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.222501
     
15. 94 b-Decay Half-Lives of Neutron-Rich 55Cs to 67Ho: Experimental Feedback and Evaluation of the r-Process Rare-Earth Peak Formation, J.S.Wu et al., Physical Review Letters 118, 072701 (2017) https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.072701 
     
16. Precision measurements of absolute g-ray emission probabilities of 223Ra and decay progeny in equilibrium: S.M.Collins et al., Applied Radiation and Isotopes 102 (2015) p15-28http://dx.doi.org/10.1016/j.apradiso.2015.04.008

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