Detection of the natural<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>α</mml:mi></mml:math>decay of tungsten

Abstract

The natural $\ensuremath{\alpha}$-decay of $^{180}\mathrm{W}$ has been unambiguously detected for the first time. The $\ensuremath{\alpha}$ peak is found in a ($\ensuremath{\gamma}$, $\ensuremath{\beta}$, and neutron)-free background spectrum. This has been achieved by the simultaneous measurement of phonon and light signals with the CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) cryogenic detectors. A half-life of ${T}_{1∕2}=(1.8\ifmmode\pm\else\textpm\fi{}0.2)\ifmmode\times\else\texttimes\fi{}{10}^{18}\phantom{\rule{0.3em}{0ex}}\text{years}$ and an energy release of $Q=[2516.4\ifmmode\pm\else\textpm\fi{}1.1(\mathrm{stat.})\ifmmode\pm\else\textpm\fi{}1.2(\mathrm{sys.})]\phantom{\rule{0.3em}{0ex}}\mathrm{keV}$ have been measured. New limits are also set on the half-lives of the other naturally occurring tungsten isotopes.