A measurement of the polonium production in a solid Bi target, placed in a high thermal neutron flux of 2.3 $10^{13}$ n/cm$^{2}$/s, was performed. Two different activation methods, based on $\\alpha$ and $\\gamma$ spectroscopy, were used to cross check the results. Values of (16.08 $\\pm$ 1.8) mb and (18.4 $\\pm$ 0.9) mb for the $^{210}Po$ (i.e. $^{210gs}Bi$) formation cross section were obtained and a recommended value of (17.9 $\\pm$ 0.8) mb was proposed. Our results are in disagreement with adopted cross section values in the main nuclear data libraries, namely smaller by 25\\% for $^{210gs}Bi$. These new values will account for more precise evaluations of $^{210}Po$ formation in moderated spallation targets containing $^{209}Bi |
