Absolute Excitation Function of theBe9(d,t)Reaction

The gas counting technique used earlier for the absolute assay of natural waters for tritium has been applied to the reactions producing tritium by the deuteron bombardment of beryllium. Absolute yield measurements for both thick and thin beryllium targets with deuteron energies ranging from 350 kev to 7.7 Mev have shown that the reaction cross section rises rapidly at about 1.5 Mev to a flat plateau at 0.23±0.01 barn, extending up to 7.7 Mev. From these results the tritium production appears to be about as prolific as the neutron production. In general one feels that the large magnitude of the ($d,t$) cross section must be associated with the low binding energy of the extra neutron in ${\mathrm{Be}}^9$.