Photonuclear tritium yields at 90 MeV

Abstract Photonuclear (γ, t) yields have been determined for Al, Zn, Sn and Bi using 90 MeV bremsstrahlung from the NBS electron synchrotron. The National Bureau of Standards P2 ionization chamber was used for primary monitoring of the bremsstrahlung beam; supplementary C and Cu activation foils, whose absolute yields are reported, were employed for relative intensity measurements. Tritium yields were determined by quantitative extraction from the molten samples with hydrogen carrier followed by activity measurement by means of low-level gas counters. The observed yields were generally consistent with those of other workers at lower energies. Comparison of the tritium yields with the results of statistical model calculations suggests the predominance of non-evaporative processes in the higher mass region (A ⪆ 100) .