In spite of ingenious investigations of the isomeric decay of 253-day ${\mathrm{Ag}}^{110m}$ by several groups of authors, the missing low-energy first excited (2-) state in ${\mathrm{Ag}}^{110}$ has so far escaped detection. High-precision studies of the $\gamma$ rays from the ${\mathrm{Ag}}^{109}(n,\gamma ){\mathrm{Ag}}^{110}$ reaction, as well as coincidence studies, now provide conclusive evidence for this level at an energy of 1.28 ± 0.10 keV.

• Received 9 March 1970

DOI:https://doi.org/10.1103/PhysRevC.2.314