Geochemical constraints on the half-life of Te130

To determine the half-life of Te130 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 Xe130/Xe132 ratio of fluids trapped inside the tellurides to be determined. Considering only samples where the trapped Xe130/Xe132 ratio is demonstrably consistent with atmospheric xenon, we can avoid over- or under-estimating the half-life due to redistribution or inheritance of radiogenic Xe130. 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±1.1)×1020 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 Xe126 production by solar neutrinos, but it is possible that geologically useful chronological information can be obtained from this system. © 2008 The American Physical Society.