Recoil properties of radionuclides formed in the photonuclear reactions onnatCu at intermediate energies

The recoil properties of 26 radionuclides produced in the photonuclear reactions on Cu at bremsstrahlung end-point energies (E0) of 250 to 1000 MeV have been investigated using the thick-target thick-catcher method. Kinematic properties of the product nuclei were calculated by the two-step vector velocity model. The calculated mean kinetic energies,T, of product nuclei increase with increase of the mass difference between products and target, reflecting the resonance natures and absorption mechanisms. TheT atE0≥600 MeV were well reproduced by a calculation performed by PICA code byGabriel andAlsmiller atE0=400 MeV, except for (γ,xn) products by giant-resonance.