Decay ofPr137

Abstract

A praseodymium isotope with a half-life of 75 min has been assigned to 137 Pr. It decays with a iC-captureto-positron ratio of 2.5±0.2 and a maximum positron energy of 1.74±0.05 MeV. Approximately 6% of the disintegrations are to excited states of 137 Ce. The energies and intensities of 28 gamma-ray transitions were measured with a Ge(Li) detector. Coincidences of the gamma rays were measured using two 3-in. Nal(Tl) crystals and a multiparameter analyzer. An energy-level diagram consistent with the observed gamma-ray energies, intensities, and coincidences has been deduced.

High-spin levels in137,139Ce and139,141Nd evidence for hole-core coupling

“…Information about the low-spin excited states of the obtained from decay studies [1][2][3][4] and from neutron pick-up reactions performed for the N = 81 nuclei [5,6]. These investigations have shown that in these nuclei the lowest states with spins and parities 3/2 + , 1/2 + and 11/2-are predominantly neutron singlehole states.…”