SEARCH Articles Figures Tables A schematic representation of the relative yield of various nuclides from photonuclear reactions with 320 Mev X-rays. The yield is indicated by the height above the proton-neutron plane. The dark line in the proton-neutron plane indicates the center of the valley of stability. Figure from Halpern etal.i Phys. Rev. 97, 1327 . [Publishers Imprint]