FE-50 BETA-DECAY

The beta(+) decay of Fe-50 (t(1/2) = 155 +/- 11 ms) has been observed for the first time; it exhibits a superallowed branch (77 +/- 6%) to t he 0(+) ground state of Mn-50 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 measure ment of the Q(EC)-value difference between the superallowed branches o f Mn-50 and Co-54, an important datum in determining the value for the Vector Coupling Constant in nuclei. Precise energies have also been d etermined for beta delayed gamma rays from the decay of Mn-50m. Crown copyright (C) 1997 Published by Elsevier Science B.V.