Determination of the Bi 209 ( n , γ ) Bi 210 g cross section using the NICE detector

The capture cross section of $^{209}\mathrm{Bi}(n,\ensuremath{\gamma})^{210g}\mathrm{Bi}$ was measured at different astrophysically relevant energies including thermal capture cross section (25 meV), resonance integral, and the Maxwellian averaged cross section at a thermal energy of $kT=30$ keV. The partial capture cross section $({\ensuremath{\sigma}}_{g})$ was determined using the activation technique and by measuring the $^{210}\mathrm{Po}$ activity. The newly developed and tested NICE detector setup was used to measure the $\ensuremath{\alpha}$ activity of the $^{210}\mathrm{Po}$. Using this setup the thermal and resonance integral cross sections were determined to be $16.2\phantom{\rule{0.28em}{0ex}}\ifmmode\pm\else\textpm\fi{}\phantom{\rule{0.28em}{0ex}}0.97$ mb and $89.81\phantom{\rule{0.28em}{0ex}}\ifmmode\pm\else\textpm\fi{}\phantom{\rule{0.28em}{0ex}}8.0$ mb, respectively. And the Maxwellian average cross section was measured to be $2.01\phantom{\rule{0.28em}{0ex}}\ifmmode\pm\else\textpm\fi{}\phantom{\rule{0.28em}{0ex}}0.38$ mb.