New Measurement of 165Ho Photoneutron Cross Section at SLEGS

Abstract: Accurate photoneutron cross section data for \(^{165}\mathrm{Ho}\) are essential for a wide range of applications, including nuclear reactor design, nuclear structure analysis, and astrophysical nucleosynthesis studies. However, existing datasets exhibit considerable inconsistencies, with cross section deviations reaching 50\% near 10~MeV and obvious mismatches in resonant peak positions, which restrict the accuracy of relevant theoretical models and engineering calculations. To resolve these discrepancies and supplement reliable experimental data, precise measurements of the \(^{165}\mathrm{Ho}(\gamma, n)\) photoneutron cross section were conducted over the photon energy range of 8.27--14.3~MeV in this work. The measurements were performed using a well-calibrated, high-efficiency LaBr\(_3\) detector combined with a 4\(\pi\) flat-efficiency \(^{3}\)He neutron detection array, yielding an overall experimental uncertainty of approximately 3.9\%. A comprehensive comparison and error analysis between the present measurements and previously reported datasets are presented in detail. Additionally, the intrinsic quadrupole moment of \(^{165}\mathrm{Ho}\), derived via the generalized Lorentzian \(\gamma\)-strength function, was determined to be \(7.57 \pm 0.21\)~b. The results obtained in this study provide a reliable and valuable reference for future nuclear reactor design and associated nuclear physics investigations.