Tritium Production by High-Energy Protons

Abstract

The cross sections for tritium production in various substances by 450-Mev and 2.05-Bev protons have been measured. The nitrogen and oxygen cross sections---25\ifmmode\pm\else\textpm\fi{}4 mb and 30\ifmmode\pm\else\textpm\fi{}4 mb, respectively, at 2.05 Bev---lead to a world-wide average tritium production rate by cosmic rays of ${0.14}_{\ensuremath{-}0.03}^{+0.10}$ tritons/${\mathrm{cm}}^{2}$ sec, in good agreement with the observed value. The iron cross section---53\ifmmode\pm\else\textpm\fi{}8 mb at 2.05 Bev---suggests a rate of production of 8.8\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}4}$ triton/g sec near the surface of a large meteorite in outer space. For the small Mt. Ayliff iron meteorite an age of 1.4\ifmmode\times\else\texttimes\fi{}${10}^{9}$ years was calculated from the observed ${\mathrm{He}}^{3}$ content. Finally, the results for tritium production have been compared to those for other light particles.