Nuclear Spectroscopy: From Natural Radioactivity to Studies of Exotic Isotopes. Prof. Paddy Regan



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Nuclear Spectroscopy: From Natural Radioactivity to Studies of Exotic Isotopes.

  • Prof. Paddy Regan

  • Chair of Radionuclide Metrology,

  • Department of Physics

  • University of Surrey, Guildford,

  • &

  • Radioactivity Group,

  • National Physical Laboratory,

  • Teddington

  • p.regan@surrey.ac.uk


Outline of talk

  • Elements, Isotopes and Isotones

  • Alpha, beta and gamma decay

  • Primordial radionuclides…..why so long ?

  • Internal structures, gamma rays and shells.

  • How big is the nuclear chart ?

  • What could this tell us about nucleosynthesis?

























Nuclei can also decay by  emission.. ejection of a 4He nucleus…. Depends (again) on binding energies & masses



Radioactive decays occur as a result of

  • Radioactive decays occur as a result of

  • conservation of mass/energy E=mc2













How do you measure the gammas? i.e., How do you see inside the nucleus?











Making a Radiological Map of Qatar

  • Arabic Gulf state,

  • Oil Rich (oil industry all around)

  • To host World Cup (2022)















Characteristic gamma signatures can be used

  • Characteristic gamma signatures can be used

  • to measure emissions of radionuclides from

  • ‘man-made sources’ such as Fukushima,

  • Chernobyl, nuclear weapons tests…etc.

    • Nuclear Fission fragments:
      • 137Cs (T1/2 = 30 years)
      • 131I (T1/2 = 8 days)
    • Neutron-capture on fission products in reactors
      • 134Cs (T1/2 = 2 years)






Summary

  • Radionuclides (e.g. 235U, 238U, 232Th, 40K) are everywhere.

  • Radioactive decays arise from energy conservation and other (quantum) conservation laws.

  • Characteristic gamma ray energies tell us structural info.




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