Observation of photonuclear reactions on isomeric targets: Hf-178(m(2))(gamma,n)Hf-177(m(2)),Ta-180(m)(gamma,2n)Ta-178(m,g) and Ta-180(m)(gamma,p)Hf-179(m(2))

Photonuclear reactions on isomeric and ground state Hf and Ta targets were studied systematically by activation technique. The reaction yields were measured and isomer-to-ground state ratios Y-m/Y-g were deduced. The systematics of the Y-m/Y-g values versus spin difference of initial and final states in the photonuclear reaction shows that the structure selectivity for the population of the levels does not survive at high excitation energies.