Geochemical constraints on the half-life ofTe130

To determine the half-life of ${}^{130}\mathrm{Te}$ we have analyzed multiple aliquots of geological telluride samples 100 times smaller than those previously reported using a unique resonance ionization mass spectrometer. We employ a low-fluence neutron irradiation that allows determination of parent and daughter from the same xenon isotopic analysis. Step heating of these irradiated samples allows the ${}^{130}\mathrm{Xe}$/${}^{132}\mathrm{Xe}$ ratio of fluids trapped inside the tellurides to be determined. Considering only samples where the trapped ${}^{130}\mathrm{Xe}$/${}^{132}\mathrm{Xe}$ ratio is demonstrably consistent with atmospheric xenon, we can avoid over- or under-estimating the half-life due to redistribution or inheritance of radiogenic ${}^{130}\mathrm{Xe}$. Combining our work with literature data, it is clear that several relatively young samples have retained xenon quantitatively since formation, allowing the half-life to be determined as $(8.0\pm 1.1)\times {10}^{20}$ yr. Older samples have clearly been affected by post-formation processing. This suggests that there is little hope of monitoring solar luminosity through the geological record of ${}^{126}\mathrm{Xe}$ production by solar neutrinos, but it is possible that geologically useful chronological information can be obtained from this system.