The Production of Protons from Carbon by Monoenergetic Gamma Rays

A technique is described for selecting from the interactions produced by a bremsstrahlung spectrum only those arising from essentially monoenergetic quanta. These interactions are selected by requiring a coincidence with the degraded electron which produced the interacting quanta.A study of the photoproduction of protons from carbon was made using 190-Mev monochromatic quanta from the 310-Mev Cornell synchrotron. An energy distribution of the emitted protons was observed at 60 degrees and an angular distribution of 70-Mev protons was also obtained. Interpretation of these results in terms of a deuteron model gives satisfactory agreement and indicates that the photoproduction process involves only a few nucleons on the average and probably involves just two nucleons a large fraction of the time. Rough quantitative agreement is obtained with experiments on the photodisintegration of the deuteron.