Decay ofPd111andPd111m

The decay of 22-min ${\mathrm{Pd}}^{111}$ and 5.5-h ${\mathrm{Pd}}^{111m}$ was studied using scintillation-spectrometer and coincidence techniques. The 22-min activity was studied in equilibrium with ${\mathrm{Pd}}^{111m}$ and also independently, and it was observed to emit gamma rays of energies 70, 160, 280, 385, 400, 500, 560, 630, 750, 830, 960, 1130, 1380, and 1440 keV. Gamma rays of energies 1080, 1250, 1640, 1690, and 1900 keV were observed only in the decay of 5.5-h activity. The beta spectrum of both the activities extends up to 2110 keV. From the beta-gamma and gamma-gamma cascade relationships, a decay scheme with levels in ${\mathrm{Ag}}^{111}$ at 70, 120, 280, 385, 470, 560, 1015, 1220, 1515, 1640, 1760, 1810, 1850, and 1970 keV has been proposed. Possible spins and parities for these levels are discussed.