Isomeric yield ratios of 148Pm from the natSm(γ, x) and the natNd(p, xn) reactions

The independent isomeric yield ratios of 148 Pm from the nat Sm(γ, x) reaction at the end-point bremsstrahlung energy of 45–64 MeV have been determined using an off-line γ-ray spectrometric technique at the 100 MeV electron linac of Pohang accelerator laboratory, Pohang, Korea. We also have determined the isomeric yield ratios of 148 Pm from the nat Nd(p,xn) reactions in the proton energy of 5.08–44.72 MeV by a stacked-foil activation and an off-line γ-ray spectrometric techniques at the MC-50 cyclotron of the Korean Institute of Radiological and Medical Sciences, Korea. The determined isomeric yield ratios of 148 Pm were compared with literature data and theoretical values estimated by the TALYS 1.4. The present data along with the similar data from literature at other energies shows that the isomeric yield ratio of 148 Pm increases with the excitation energy both in the nat Sm(γ, x) and the nat Nd(p, xn) reactions. The isomeric yield ratios of 148 Pm from the nat Nd(p, xn) reactions are always higher than those from the nat Sm(γ, x) reactions at the same excitation energy, which indicate the role of input angular momentum besides excitation energy.