Using an unusual technique for precisely locating γ ray peaks in a spectrum from a Ge semiconductor detector, the energy of the 2.31-MeV γ ray which follows ${}^{14}\mathrm{O}$ positron decay has been measured on a scale derived from the known energies of ${}^{56}\mathrm{Co}$ lines, as have the energies of the 2.18- and 2.32-MeV γ rays which follow the decay of ${}^{90}\mathrm{Nb}.$ Values of 2312.603(10), 2186.253(10), and 2318.973(10) keV, respectively, were determined. When taken together with updated, previously accepted values, these lead to recommended energies of 2312.590(10), 2186.244(7), and 2318.962(6) keV.

• Received 2 August 2000

DOI:https://doi.org/10.1103/PhysRevC.63.024302