Measurement of thermal neutron cross-sections and resonance integrals for ~(179)Hf(n,γ)~(180m)Hf and ~(180)Hf(n,γ)~(181)Hf reactions at the Pohang neutron facility

摘要

The thermal-neutron cross-sections and the resonance integrals for the ~(179)Hf(n,γ)~(180m)Hf and the ~(180)Hf(n,γ)~(181)Hf reactions have been measured by the activation method. The high purity Hf and Au metallic foils within and without a Cd shield case were irradiated in a neutron field of the Pohang neutron facility. The gamma-ray spectra from the activated foils were measured with a calibrated p-type high-purity Ge detector. In the experimental procedure, the thermal neutron cross-sections, σ_0, and resonance integrals, I_0, for the ~(179)Hf(n,γ)~(180m)Hf and the ~(180)Hf(n,γ)~(181)Hf reactions have been determined relative to the reference values of the ~(197)Au(n,γ)~(198)Au reaction, with σ_0 = 98.65 ± 0.09 barn and I_0 = 1550 ± 28 barn. In order to improve the accuracy of the experimental results, the interfering reactions and necessary correction factors were taken into account in the determinations. The obtained thermal neutron cross-sections and resonance integrals were σ_0 = 0.424 ± 0.018 barn and I_0 = 6.35 ± 0.45 barn for the ~(179)Hf(n,γ)~(180m)Hf reaction, and σ_0 = 12.87 ± 0.52 barn and I_0 = 32.91 ± 2.38 barn for the ~(180)Hf(n,γ)~(181)Hf reaction. The present results are in good agreement with recent measurements.