Photoprotons Produced by 245±15-Mev Gamma Rays on Carbon

A carbon target was bombarded by 342-Mev bremsstrahlung from the Berkeley synchrotron. The energy spectrum of protons produced at 60 deg was measured from 90-250 Mev. Interactions due to 245±{}15 Mev gamma rays were selected out by requiring a coincidence between the protons from the target and the electrons associated with these gamma rays. Analysis was made using the quasi-deuteron model of Levinger. In contrast with previous analyses of this kind, conservation of both momentum and energy were taken into account in a fairly accurate way. Results of this analysis determine the momentum distribution of the centers of mass of the quasi-deuterons. The momentum distribution that results in the observed proton spectrum, normalized to one quasi-deuteron, is given by ${{d}³N}{d{{P}D}³}={0.2}{{(4{π}M{E}₁)}3/2}exp({-}{{{P}D}²}{4M{E}₁})+{0.8}{{(4{π}M{E}₂)}3/2}exp({-}{{{P}D}²}{4M{E}₂}),$ where ${E}₁=1.6$ Mev, ${E}₂=20$ Mev.