Coincident neutron-proton pairs were measured from the reaction ${}_{}{}^3{}_{}{}^{}\mathrm{He}$(γ,np)p with a 100-MeV bremsstrahlung beam. The energy and angle of the neutron and proton were used to reconstruct the photon energy, making this a kinematically complete experiment. Quasi-deuteron breakup was observed for photon energies from 45 to 95 MeV. The angular distribution of the np pairs was measured for opening angles from 122 to 202 degrees in the laboratory frame. The single-differential cross section in ${\mathrm{\Omega }}_{\mathit{p}}$ was determined at ${\mathrm{\theta }}_{\mathit{p}}$=81°, relative to deuterium, to range from 2.4 at 55 MeV to 1.7 at 95 MeV.

• Received 12 November 1990

DOI:https://doi.org/10.1103/PhysRevC.44.37