Spicer's shell-model 1p-1h calculation for photoabsorption in ${\mathrm{S}}^{32}$ indicates that considerable dipole strength should be expected in the regions 3 and 10 MeV above the giant resonance peak. The ${\mathrm{S}}^{32}(\gamma , n){\mathrm{S}}^{31}$ reaction cross section has been measured in 250-keV steps from 20 to 32 MeV, and qualitatively confirms these gross predictions. The present cross section has been normalized to that reported by Thompson, Taylor, and Webb. To account for the detailed structure that appears in the composite cross section, a calculation has been carried out including the coupling of the surface vibration phonons to the 1p-1h dipole states, as described by Drechsel, Seaborn, and Greiner. The calculation increases the number of states carrying appreciable absorption strength, as well as transferring strength to higher energies. The over-all agreement between the theoretical result and the ($\gamma , n$) cross section is remarkably good.

• Received 4 August 1967

DOI:https://doi.org/10.1103/PhysRev.164.1397