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)He-4 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 Th-232(n,2n)Th-231 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 Th-232(n,2n)Th-231 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.