Redetermination of several half-lives

Discovery, nuclear properties, synthesis and applications of technetium-101

Technetium-101 (101Tc) has been poorly studied in comparison with other Tc isotopes, although it was first identified over ~80 years ago shortly after the discovery of the element Tc itself. Its workable half-life and array of production modes, i.e., light/heavy particle reactions, fission, fusion-evaporation, etc., allow it to be produced and isolated using an equally diverse selection of chemical separation pathways. The inherent nuclear properties of 101Tc make it important for research and applications related to radioanalytical tracer studies, as a fission signature, fusion materials, fission reactor fuels, and potentially as a radioisotope for nuclear medicine. In this review, an aggregation of the known literature concerning the chemical, nuclear, and physical properties of 101Tc and some its applications are presented. This work aims at providing an up-to-date and first-of-its-kind overview of 101Tc that could be of importance for further development of the fundamental and applied nuclear and radiochemistry of 101Tc.

A new measurement of the 122Sb half-life

Following significant discrepancies observed when decay-correcting 122Sb γ-peak count rates to a reference time, we looked at the literature supporting the presently recommended 2.7238(2) d (1σ) 122Sb half-life value as the source of these discrepancies. Investigation revealed that the value was derived from an inconsistent dataset and was published without reporting details of the experiment nor the uncertainty budget. In this work we performed a new measurement of the 122Sb half-life by measuring the 122Sb decay of neutron-activated antimony samples using state-of-the-art γ-detection systems characterized in terms of efficiency drift and random pulse pile-up. The measurement was carried out in two different laboratories with the same method. The resulting 2.69454(39) d  and 2.69388(30) d (1σ) 122Sb half-life values are in agreement at the evaluated 10–4 relative combined standard uncertainty level but are significantly lower (1.07% and 1.10% lower, respectively) than the preexisting recommended value.

The decays of (109,111)Pd and (111)Ag following neutron capture by Pd

Improved precisions of the energies and intensities of the γ rays emitted in the decays of (109)Pd and (111g,m)Pd have been obtained based on a high-resolution spectroscopic study of these γ emissions from radioactive samples produced by neutron capture by natural Pd. Correspondingly improved values of the energies and β feedings of the levels in the (109,)(111)Ag daughters have been deduced. More precise energies and intensities have also been determined for the γ rays emitted in the decays of the (111)Pd daughter activities (111g,m)Ag to (111)Cd.