Photoprotons from Sodium

The energy and angular distributions of photoprotons from sodium irradiated with 18 Mev bremsstrahlung were measured. Protons were detected by nuclear emulsions 200 mu thick placed radially around the target. The energy spectrum is shown in 200 kev intervals. Peaks were obtained at 7.2, 6.3, 5.3, 4.9, and 3.9 Mev. (W.D.M.)