Skobeltsyn Institute of Nuclear Physics
Lomonosov Moscow State University

The 54,56Fe and 58,60Ni photonuclear reactions (g,n), (g,p), (g,np), and (g,2n) cross sections have been evaluated for initial g-quanta energies 10 - 40 MeV using the model based on the

phenomenological description of the main giant dipole resonance (GDR) decay channel competition. Parametrization of the main GDR state excitation and decay mechanisms has

been carried out using the analysis of systematics of the A-dependencies of integrated cross section ratios for reactions (g,sn) and (g,2n), (g,sn) and (g,xp), (g,xp) and (g,np) for nuclei with

A = 10 - 210. For proton decay channel the coulomb barrier effects have been taken into account and for neutron one - the isospin (for nuclei with N not equal to Z) selection rules effects. The

dependencies E-GDR (MeV) = 31.2 A**(-1/3) + 20.6 A**(-1/6) and SIGMA-int-GDR = 60 NZ/A have been used for energy position and integrated cross section description correspondingly. On the whole the

agreement of the evaluated reaction cross sections with experimental ones for 54,56Fe and 58,60Ni is about 15 - 20 percent.

Research was carried out in the Department of Electromagnetic Processes and Atomic Nuclei Interaction (DEPANI) and was supported in part by the International Atomic Energy Agency

(IAEA) under the Research Contract N 8839.