Thermal neutron capture by Pb-208

We have observed seven \ensuremath{\gamma} rays following subthermal-neutron capture by ${}^{208}\mathrm{Pb}$ and incorporated them into a level scheme of ${}^{209}\mathrm{Pb}$ consisting of five excited levels. The measured neutron separation energy of ${}^{209}\mathrm{Pb}$ is 3938.0\ifmmode\pm\else\textpm\fi{}0.5 keV. The thermal-neutron capture cross section of ${}^{208}\mathrm{Pb}$ was determined to be 230\ifmmode\pm\else\textpm\fi{}12 \ensuremath{\mu}b. The theoretical estimates are 860 \ensuremath{\mu}b or 550 \ensuremath{\mu}b, depending on the model used for the compound-nuclear component; however, these values are not inconsistent with the data if the statistical distribution of the theoretical estimates is taken into account. The thermal-neutron capture cross sections for ${}^{206}\mathrm{Pb}$ and ${}^{207}\mathrm{Pb}$ were also determined and found to be 26.6\ifmmode\pm\else\textpm\fi{}1.2 mb and 610\ifmmode\pm\else\textpm\fi{}30 mb, respectively.