Measurement of theSi32Half-Life via Accelerator Mass Spectrometry

The half-life of ${}_{}{}^{32}{}_{}{}^{}\mathrm{Si}$ has been measured to be $T_{\frac{1}{2}}=101\mathrm{}\pm 18$ yr, considerably shorter than the previously accepted value of ≈ 300 yr. The new value was obtained by measuring the specific $\beta$ activity with a liquid-scintillation-counter technique and the ${}_{}{}^{32}{}_{}{}^{}\mathrm{Si}$ concentration with tandem-accelerator mass spectrometry. It is expected that the present result will have a strong impact on studies with cosmogenic ${}_{}{}^{32}{}_{}{}^{}\mathrm{Si}$.