The $$^{146}\text{Sm}$$ half-life re-measured: consolidating the chronometer for events in the early Solar System
Nadine M. Chiera, P. Sprung, Yuri Amelin, R. Dressler, D. Schumann, Zeynep Talip
Abstract
Abstract The half-life of the extinct radiolanthanide $$^{146}\text{Sm}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mmultiscripts> <mml:mrow/> <mml:mrow/> <mml:mn>146</mml:mn> </mml:mmultiscripts> <mml:mtext>Sm</mml:mtext> </mml:mrow> </mml:math> , important for both geochronological and astrophysical applications, was re-determined by a combination of mass spectrometry and $$\alpha$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>α</mml:mi> </mml:math> -decay counting. Earlier studies provided only limited information on all potential factors that could influence the quantification of the half-life of $$^{146}\text{Sm}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mmultiscripts> <mml:mrow/> <mml:mrow/> <mml:mn>146</mml:mn> </mml:mmultiscripts> <mml:mtext>Sm</mml:mtext> </mml:mrow> </mml:math> . Thus, special attention was given here to a complete documentation of all experimental steps to provide information about any possible artifacts in the data analysis. The half-life of $$^{146}\text{Sm}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mmultiscripts> <mml:mrow/> <mml:mrow/> <mml:mn>146</mml:mn> </mml:mmultiscripts> <mml:mtext>Sm</mml:mtext> </mml:mrow> </mml:math> was derived to be 92.0 Ma ± 2.6 Ma, with an uncertainty coverage factor of $$\mathsf{\textit{k}\!=\!1}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>k</mml:mi> <mml:mspace/> <mml:mo>=</mml:mo> <mml:mspace/> <mml:mn>1</mml:mn> </mml:mrow> </mml:math> .