The neutron total cross section is one of the most fundamental nuclear data. In the low-energy resonance region, discrepancies among measurements are caused by experimental backgrounds, sample self-shielding, and instrumental broadening, complicating the precise determination of cross sections. In this work, the neutron total cross sections of ¹⁶⁹Tm were measured at the Back-n facility of the China Spallation Neutron Source (CSNS). Wing-shaped lithium glass detectors were employed to record the transmitted neutron signals from samples with thicknesses of 0.5 mm and 4.5 mm. The raw data were processed, including time-of-flight correction and normalization to the incident proton number, to account for fluctuations in the proton beam intensity. The in-beam γ background was quantified using the saturated resonance absorption technique with glass scintillators. Following background subtraction, transmission and total cross-section data were obtained over the energy range of 1–100 eV. The measured spectra were analyzed using the SAMMY code within the framework of the R-matrix. Capture data from Ren et al. were incorporated to improve the reliability of the extracted resonance parameters. For the resonance near 8 eV, the Γγ was set to the library average value of 86 meV. The resonance energy was determined to be 8.037 eV, consistent with the recently reported resonance by I. Knapová et al., and the neutron widths for both total spin states were evaluated. Based on the extracted parameters, the neutron total cross section of ¹⁶⁹Tm was reconstructed using the Reich–Moore approximation. The reconstructed cross section shows good agreement with those recommended by ENDF/B-VIII.1 library, confirming the reliability of the resonance parameters extracted from the capture–transmission measurements. Overall, the present measurements and analysis provide a set of resonance parameters for ¹⁶⁹Tm, enhancing the experimental foundation for both nuclear physics research and nuclear industry.
The datasets presented in this paper, including the neutron transmission, neutron total cross section, and resonance parameters are openly available at https://www.doi.org/10.57760/sciencedb.j00213.00192 (Please use the private access link https://www.scidb.cn/s/MrUVry to access the dataset during the peer review process)