Measurements of ²³²Th(n,2n) ²³¹Th reaction cross-sections in the neutron energy of 12–18.5 MeV

At the 3MV tandem accelerator of Sichuan University, monoenergetic neutrons were generated through the T(d,n)⁴He reaction by bombarding a Tritium–Titanium (T–Ti) target with a 2 MeV deuterium beam. The neutron activation method and offline gamma-ray spectroscopy were utilized to measure the cross sections of the ²³²Th(n,2n)²³¹Th reaction at neutron energies of 12.49 ± 0.33 MeV, 16.38 ± 0.60 MeV, and 18.10 ± 0.23 MeV. Factors such as neutron scattering, neutron flux fluctuation, cascade coincidence effects in gamma-ray measurements, and gamma-ray self-absorption were analytically corrected. The TALYS-1.9 program was used to calculate the reaction cross sections of ²³²Th(n,2n)²³¹Th within the 6–20 MeV neutron energy range. The experimental data were compared and analyzed against existing experimental data, evaluated data from CENDL-3.2, ENDF/B-VIII, JENDL-5, ROSFONDR-2010 and theoretical values computed by TALYS-1.9.