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

Abstract

The thermal neutron cross-section and the resonance integral of the Ho-165(n,gamma)Ho-166g reaction have been measured by the activation method using a Au-197(n,gamma)Au-198 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 gamma-ray attenuation (F-g), the thermal neutron self-shielding (G(th)), the resonance neutron self-shielding (G(epi)) effects, and the epithermal neutron spectrum shape factor (alpha) were taken into account. The thermal neutron cross-section for the Ho-165(n,gamma)Ho-166g reaction has been determined to be 59.7 +/- 2.5 barn, relative to the reference value of 98.65 +/- 0.09 barn for the Au-197(n,gamma)Au-198 reaction. By assuming the cadmium cut-off energy of 0.55 eV, the resonance integral for the Ho-165(n,gamma)Ho-166g reaction is 671 +/- 47 barn, which is determined relative to the reference value of 1550 +/- 28 barn for the Au-197(n,gamma)Au-198 reaction. The present results are, in general, good agreement with most of the previously reported data within uncertainty limits. (C) 2010 Elsevier B.V. All rights reserved.