The phototriton cross section of ${\mathrm{Li}}^6$ has been measured between 24- and 35-MeV photon energy. This work complements an earlier experiment which established the production of the ${\mathrm{Li}}^6(\gamma ,t)$ reaction by giant-resonance photons and measured the cross section between 19 and 24 MeV. The phototriton cross section of ${\mathrm{Li}}^6$ falls monotonically from 0.46±0.24 mb at 19 MeV to 0.11±0.06 mb at 35 MeV. The integrated ($\gamma ,t$) cross section over this energy interval is 4.9±2.5 MeV mb. The measured bremsstrahlung-weighted cross section is 0.18±0.09 mb. Implications concerning the nuclear size are discussed.

• Received 31 October 1967

DOI:https://doi.org/10.1103/PhysRev.169.771