Photoactivation of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow/><mml:mrow><mml:mn>180</mml:mn></mml:mrow></mml:msup></mml:mrow><mml:mrow><mml:msup><mml:mrow><mml:mi mathvariant="normal">Ta</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="italic">m</mml:mi></mml:mrow></mml:msup></mml:mrow></mml:math>and Its Implications for the Nucleosynthesis of Nature's Rarest Naturally Occurring Isotope

The depopulation of the quasistable isomer in ${}^{180}\mathrm{Ta}$ with ${J}^{\ensuremath{\pi}}{\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}9}^{\ensuremath{-}}$ at ${E}_{x}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}75\mathrm{keV}$ by resonant photoabsorption was investigated with intense bremsstrahlung. The results indicate a dramatic acceleration of the isomer decay to the short-lived ${J}^{\ensuremath{\pi}}{\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1}^{+}$ ground state under stellar $s$-process conditions. The consequences for a possible nucleosynthesis of nature's rarest isotope ${}^{180}\mathrm{Ta}$ within the $s$ process are discussed.