Measurement of thermal neutron cross-section and resonance integral for the 165Ho(n,γ)166gHo reaction using electron linac-based neutron source

The thermal neutron cross-section and the resonance integral of the 165Ho(n,γ)166gHo reaction have been measured by the activation method using a 197Au(n,γ)198Au monitor reaction as a single comparator. The high-purity natural Ho and Au foils with and without a cadmium shield case of 0.5 mm thickness were irradiated in a neutron field of the Pohang neutron facility. The induced activities in the activated foils were measured with a calibrated p-type high-purity Ge detector. The correction factors for the γ-ray attenuation (Fg), the thermal neutron self-shielding (Gth), the resonance neutron self-shielding (Gepi) effects, and the epithermal neutron spectrum shape factor (α) were taken into account. The thermal neutron cross-section for the 165Ho(n,γ)166gHo reaction has been determined to be 59.7 ± 2.5 barn, relative to the reference value of 98.65 ± 0.09 barn for the 197Au(n,γ)198Au reaction. By assuming the cadmium cut-off energy of 0.55 eV, the resonance integral for the 165Ho(n,γ)166gHo reaction is 671 ± 47 barn, which is determined relative to the reference value of 1550 ± 28 barn for the 197Au(n,γ)198Au reaction. The present results are, in general, good agreement with most of the previously reported data within uncertainty limits.