Measurement of the 232Th Neutron Capture Cross Section in the Region 5 keV–150 keV.

The average capture cross-section of 232Th has been measured at the 14.37 m flight path of GELINA, IRMM-Geel, in the energy range from 5 to 150 keV. The capture events were detected by two C6D6 liquid scintillators and the neutron flux was measured with a 10B-loaded ionisation chamber. The data, corrected with the pulse-height weighting technique, have been normalised to the well-isolated and nearly saturated 232Th(n, γ) resonances at 21.8 eV and 23.5 eV. Below 15 keV neutron energy, we do not observe the discrepancies, up to 40%, with the evaluated ENDF/B-VI data as reported by Wisshak et al.. Between 5 and 80 keV our results are about 10% systematically above the ENDF/B-VI data and approach the evaluated data between 80 and 100 keV.