Measurements of Tritium and ¹⁴C Production Cross Sections for 14.7-MeV Neutrons on ¹⁷O and ¹⁸O

Samples of water isotopically enriched in ¹⁷O, ¹⁸O, and ²H along with natural water were bombarded by neutrons from the intense deuterium-tritium source provided by the Fusion Neutron Source facility. After irradiation, the accumulated concentrations of ³H and ¹⁴C activities were determined by the liquid scintillation method. Special attention was paid to ¹⁴C losses in the gas phase during irradiation and preparation of scintillation counting samples. Cross sections for the ¹⁷O(n,)¹⁴C, ¹⁸O(n,n')¹⁴C, ¹⁷O(n,t)¹⁵N, and ¹⁸O(n,t)¹⁶N reactions at 14.7 MeV have been measured for the first time. The following values have been obtained for these reactions: 18.0 ± 3.3, 35.4 ± 6.5, 0.82 ± 0.15, and 26.8 ± 4.9 mb, respectively, relative to the ⁹³Nb(n,2n)^92mNb standard reaction cross section of 460 mb. A study of the systematics of (n,t) reactions at 14.7 MeV on light nuclei (atomic number Z < 10) has been carried out. The experimental cross-section values are also compared with data in the comprehensive activation libraries.