Measurement of Isomeric Ratio for 198-Pt(g,n)197-Pt with End-point Bremsstrahlung Energies of 55-, 60- and 65- MeV at Pohang Neutron Facility

Nuclei with an isomeric state and an unstable ground state are used for study on the structure and properties of the compound nuclei and a mechanism of the nuclear reaction. The relative population of these two states is known as the isomeric yield ratio of nuclei. The isomeric yield ratios are very important because they are useful for studying the angular momentum effects in nuclear reactions and the spin dependence of the nuclear level density. The isomeric yield ratio measured with photon has some essential advantages in studying nuclear structure and reaction mechanism. V. A. Zheltonozhsky already measured isomeric ratio of ¹⁹⁸Pt(γ,n)¹⁹⁷Pt at the bremsstrahlung ranging from 9.5 MeV to 17.0 MeV. We measured the isomeric yield ratios for the photonuclear reactions of ¹⁹⁸Pt(γ,n)¹⁹⁷Pt by the activation method and the off-line γ-ray spectrometric technique with the end-point bremsstrahlung energies of 55-, 60-, and 65-MeV using the electron linac at Pohang Neutron Facility