Photoprotons from In, Ce, and Bi

The charged particles ejected from indium, cerium, and bismuth foils by x-rays from a 24-Mev betatron were observed in nuclear emulsions. The yields of photoprotons, photodeuterons, and photoalpha particles were determined, and the energy and angular distributions of the photoprotons were measured and compared with theoretical calculations based on the evaporation process and on the direct photoeffect. The energy distributions observed indicate a large fraction of direct photoeffect. A marked forward asymmetry was observed in the angular distributions from indium and bismuth.