Speaker
Description
$^{\text{175, 176}}\text{Lu}$ (n,γ) $^{\text{176, 177}}\text{Lu}$ reactions were studied via radiative capture of resonance neutrons at the CSNS Back-n White Neutron Source. Using the time-of-flight (ToF) technique, gamma-ray spectra for isolated resonances were measured. The experiment was conducted with a coaxial HPGe gamma detector equipped with an anti-Compton system, positioned 20 cm from the target. A 60 g sample of metallic natural lutetium ($^{\text{nat}}\text{Lu}$) with 99.9% purity (dimensions: 60 × 2.2 mm) was used as the target, located 76 m from the spallation target in the ES#2 experimental hall. The ToF spectrum was measured in the 1–700 eV energy range, with sufficient γ-ray statistics up to 100 eV. The measurement time was approximately 200 hours. The ToF resolution enabled the extraction of gamma-ray spectra from 16 neutron resonances for the $^{\text{175}}\text{Lu}$ (n,γ) $^{\text{176}}\text{Lu}$ reaction. Due to the low natural abundance of $^{\text{176}}\text{Lu}$ (2.6 %), gamma-ray spectra were obtained from 10 resonances for $^{\text{176}}\text{Lu}$ (n,γ) $^{\text{177}}\text{Lu}$ reaction. In total, 40 primary gamma transitions were identified for $^{\text{176}}\text{Lu}$, but 15 for $^{\text{177}}\text{Lu}$. Resonance spins were also deduced from the analysis of gamma-transition intensities for both reactions.
Acknowledgment
We thank the staff members of the Back-n white neutron facility (https://cstr.cn/31113.02.CSNS.Back-n) at the China Spallation Neutron Source (CSNS) (https://cstr.cn/31113.02.CSNS ), for providing technical support and assistance in data collection and analysis.
