DECAY OF 111PD AND 111MPD

The energy levels of 111Ag have been investigated through study of the decay of 22 min 111Pd and 5.5 h 111mPd using high-resolution Ge(Li) and Si(Li) spectrometers and a 30 cm3 Ge(Li), 45 cm3 Ge(Li) coincidence system. More than 150 gamma transitions have been observed from the two isomers. The coincidence results, in conjunction with energy sums and relative-intensity considerations, suggest a 111Ag level scheme involving 48 energy levels below 2.2 MeV. On the basis of beta and gamma selection rules, unique spin-parity assignments are suggested for a number of the established levels. The 74 sec first excited state in 111Ag has been shown to independently beta decay to several excited states in 111Cd. It is noted that there are many similarities in the level structures of 111Ag, 109Ag and 107Ag. These nuclei seem reasonably well described by the particle-photon coupling model; however, it also appears possible that certain groups of levels are rotational in character. © 1969.