Capture cross section measurements with a total energy BGO-detector

The total energy BGO-detector was applied to measure capture cross-sections by time of flight method for the neutron energy range 10–200 keV. The properties of the detector (time and energy resolution, sensitivity to the scattered neutrons, efficiency) are discussed. The possibility of the detector was demonstrated with a tantalum cross section measurement. The capture cross section was normalized against the B(n, α1) reaction. The pulse height spectra of standard gamma-ray sources (energy range 0.1–3 MeV) were applied to calculate the weighting function. It was shown that one may use the spectra of captured γ-rays for isotopes with a well known cross section to determine the weighting function parameters. In addition the new equations for weighting function calculation were suggested.