A Study of Alpha Particle Production in Photonuclear Reactions at Photon Energies of 21 and 40 MeV

The production of alpha particles in photonuclear reactions on 65 Cu, 115 In, 92 Mo and 207 Pb targets in the beam of accelerated electrons with energy of 21 and 40 MeV was studied. The experiments were run on the Linear Electron Accelerator NLA (The Yerevan Physics Institute). The measurement results represent the yields of reactions studied as functions of the mass number of nuclei and the photon energy. The data obtained enable one to suggest a change in the mechanism of alpha particle photoproduction with increasing energy of incident photons and target mass.