50Fe Beta decay

The β+ decay of 50Fe (t12 = 155 ± 11 ms) has been observed for the first time; it exhibits a superallowed branch (77 ± 6%) to the 0+ ground state of 50Mn and an allowed branch to the 650.99 ± 0.06 keV 1+ state. The energy of the latter state has been precisely determined in order to reduce the uncertainties in a previous measurement of the QEC-value difference between the superallowed branches of 50Mn and 54Co, an important datum in determining the value for the Vector Coupling Constant in nuclei. Precise energies have also been determined for β delayed γ rays from the decay of 50mMn.