Nuclear Data Sheets for A = 161

Abstract

All known nuclear structure information on 161 Yb is presented.

Isomer Spectroscopy of Neutron-rich $^{165,167}$Tb

“…The internal conversion coefficients and intensity balances (see Table I) for the proposed level scheme imply an E1 multipolarity for the 147 keV transiton (α(E1:147 keV) = 0.1067) and an M1 decay for the 53 keV transition (α(M1:53 keV) = 13. From the reported systematics of lighter, prolate-deformed odd-A Tb isotopes, 161 Tb and 163 Tb [4,5], the likely ground state spin/parities for 165,7 Tb are I π = …”

“…The terbium isotopes (Z = 65) correspond to a single proton-hole in the 170 Dy deformed core [3] and, therefore, their structure can be used to probe the evolution of competing, prolate-deformed single-particle structures in this region of the Segré chart. Prior to this work, 163 Tb was the heaviest isotope of this element for which excited state information had been reported [4] and the systematics of the lighter odd-A Tb isotopes 161,163 Tb are consistent with ground states built on the same [1,2,4,5]. Here, we report on the decay of isomeric states in the neutron-rich systems 165 Tb and 167 Tb, and compare the deduced level schemes with long-standing predictions of which quasi-proton orbitals are favoured in this well-deformed region of the nuclear chart.…”

Isomer spectroscopy of neutron-rich 168Tb103

“…The terbium isotopes (Z = 65) correspond to a single proton-hole in the 170 Dy deformed core [3] and, therefore, their structure can be used to probe the evolution of competing, prolate-deformed single-particle structures in this region of the Segré chart. Prior to this work, 163 Tb was the heaviest isotope of this element for which excited state information had been reported [4] and the systematics of the lighter odd-A Tb isotopes 161,163 Tb are consistent with ground states built on the same [1,2,4,5]. Here, we report on the decay of isomeric states in the neutron-rich systems 165 Tb and 167 Tb, and compare the deduced level schemes with long-standing predictions of which quasi-proton orbitals are favoured in this well-deformed region of the nuclear chart.…”

The (n,2n) reaction for the lightest stable erbium isotope Er162 from reaction threshold up to 19 MeV

“…The sample was placed in the midspace of the two HPGe detectors, centered on their common axis. The absolute peak efficiency of this setup for the stronger decay line of 161 Er at 826.6 keV [26] was γ = (10.5 ± 0.4)%. The high detection efficiency of the γ spectrometer was a critical factor for accumulating satisfactory statistics from the weak induced activity of the erbium sample, given the minimal abundance (0.139%) of 162 Er in the natural composition sample.…”

“…It has to be mentioned that despite the close detection geometry and the complexity of the decay scheme of 161 Er [26], coincidence summing effects are not expected for the 826.6 keV line. Specifically, the summing-in and summingout possible effects were calculated according to the method described by Debertin and Helmer [27].…”