High precision half-life measurement of $$^{95}\hbox {Ru}$$, $$^{95}\hbox {Tc}$$ and $$^{95m}\hbox {Tc}$$ with $$\gamma $$-spectroscopy

Abstract

The precise knowledge of the half-life of the reaction product is of crucial importance for a nuclear reaction cross section measurement carried out with the activation technique. The cross section of the 92 Mo(α,n) 95 Ru reaction was measured recently using this experimental approach. The preliminary results indicated that the literature half-life of 95 Ru, derived about half a century ago, is overestimated. Therefore, the half-lives of 95 Ru and its daughter isotope 95 Tc and 95m Tc have been measured with high precision using γ-spectroscopy. The results are t 1/2 = 1.6033 ± 0.0044 h for 95 Ru, t 1/2 = 19.258 ± 0.026 h for 95 Tc and t 1/2 = 61.96 ± 0.24 d for 95m Tc. The precision of the half-life values has been increased, consequently the recently measured 92 Mo(α,n) 95 Ru activation cross section will become more precise.

Challenges and Requirements in High-Precision Nuclear Astrophysics Experiments

“…In many cases, the half-lives were measured several decades ago with outdated experimental techniques. Sometimes the literature a half-life value is based on one single measurement [41], in other cases contradicting results can be found [42]. Therefore, it is often necessary to supplement the cross section determination with a dedicated half-life measurement.…”