M.E. Bunker

Equilibrium deformations and excitation energies for non-collective states in odd-Z rare-earth nuclei☆

Abstract Nuclear potential energy surfaces have been calculated for one-quasiparticle states in the odd- Z rare-earth nuclei. The calculations are based on the Nilsson model with inclusion of nuclear pairing effects. A renormalization of the energy surface to that of a liquid drop is made using the Strutinsky method. The lowest minima in the potential energy surfaces yield deformations ( e 2 , e 4 ) and excitation energies of the one-quasiparticle states,which can be compared with the experimental values after appropriate corrections, including a contribution from zero-point rotational motion. Many of the empirical energy trends among the one-quasiparticle states are well reproduced by these calculations. Some of the observed trends are attributable to variation in the hexadecapole ( e 4 ) deformation.

Ge(Li)-Ge(Li) coincidence studies of the decay of 109Pd

Abstract The energy levels of 109 Ag that are populated in the decay of 13 h 109 Pd have been investigated with high-resolution Ge(Li) gamma-ray spectrometers. Coincidence results obtained with a Ge(Li)Ge(Li) detector system coupled with energy sums and relative intensity considerations suggest the existence of excited states in 109 Ag at 88, 133, 311, 415, 702, 724, 735, 863, 869, 911, 912 and 1099 keV. An additional state is present at either 707 or 795 keV. A comparison with previous Coulomb excitation data has been made. Spin and parity assignments are suggested for most of the states, and the level structure is discussed in terms of existing nuclear models.

The decay of 111Pd and 111mPd

Abstract The energy levels of 111 Ag have been investigated through study of the decay of 22 min 111 Pd and 5.5 h 111m Pd using high-resolution Ge(Li) and Si(Li) spectrometers and a 30 cm 3 Ge(Li), 45 cm 3 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 111 Ag 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 111 Ag has been shown to independently beta decay to several excited states in 111 Cd. It is noted that there are many similarities in the level structures of 111 Ag, 109 Ag and 107 Ag. 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.

E1 transition probabilities between the nilsson states 12+[411] and 12− [541]

Abstract The half-lives of the 1 2 , 1 2 + [411] level at 208.1 keV in 171Lu and of the 1 2 , 1 2 + [411] and 3 2 , 1 2 + [411] levels at 425.0 and 434.6 keV in 173Lu have been measured in the decay of 171Hf and 173Hf to be 29.7±1.1 ns, 0.82±0.20 ns and 0.46±0.20 ns, respectively. These half-lives yield the absolute γ-ray transition probabilities of the El transition from 1 2 , 1 2 + [411] to 1 2 , 1 2 − [541] in 171Lu and of the E1 transitions from 1 2 , 1 2 + [411] to the spin 1 2 and 1 2 members of the 1 2 − [541] band and from 3 2 , 1 2 + [411] to the spin 3 2 and 5 2 members of the 1 2 − [541] band in 173Lu. These absolute transition probabilities are found to be in good agreement with the Nilsson estimate, taking into account pairing correlations and Coriolis coupling.

Energy Levels of Ru 100

The nuclear-level structure of

ENERGY LEVELS OF

^{100}\mathrm{Ru}

sup 100

has been investigated through study of the radioactive decay of 16-sec

Ru.

^{100}\mathrm{Tc}

Decay of 245Am

and 20-h

E1-M2-E3 mixing of the 1159.3 keV transition in 176Hf

^{100}\mathrm{Rh}