Level structure of 101Rh from the decay of 8.5 h 101Pd

Abstract

The level structure of 101 Rh has been investigated from the decay of 8.5 h 101 Pd. Singles γ-ray energy and intensity measurements were taken with a 25 cm 3 high-resolution Ge(Li) detector in an anti-Compton arrangement which employed a large NaI(Tl) annular detector. Extensive γγ coincidence measurements were made with a Ge(Li)–Ge(Li) and a NaI-Ge(Li) arrangement with the Ge(Li) detector under Compton suppression. Triple γγγ coincidence measurements were taken in a NaI-Ge(Li)-NaI arrangement with the Ge(Li) detector under Compton suppression. The low-energy γ-rays and X-rays were studied with a high-resolution Si(Li) X-ray spectrometer. Conversion electron measurements were made with Si(Li) detectors and α K values were determined for the most intense transitions. From these data it was concluded that levels at 157.32, 181.78, 305.3, 355.14, 478.00, 747.67, 905.61, 974.7, 978.42, 1035.5, 1057.7, 1320.4, 1359.31, 1470.82, 1696.27, 1789.26, 1820.22 and 1911.23 keV are populated in the decay of 8.5 h 101 Pd. From log ft and α K values determined in this work and from γ-ray intensity information definite J π assignments were made to a number of levels and limits for the J π values were placed for the rest of the levels in 101 Rh. The fraction of decay of the 4.5 d isomeric state by an isomeric transition was measured to be 0.072 ± 0.004. The level structure and the level trends in the 99, 101, 103, 105 Rh isotopes are examined and discussed in relation to recently published results on calculated levels in these isotopes on the basis of an extended pairing-plus- quadrupole model for the nucleus.