Methods of producing radionuclides for spectrometric gamma-ray sources and their standardization: Pt. 1

The radionuclide 133Ba was obtained by neutron irradiation of 132BaCO3, enriched up to 28%, in a high-flux nuclear reactor. It is shown that the effective burn-up cross-section for 133Ba must be about 50 barn, provided the resonance integral for 132Ba nuclei, leading to the ground state of 133Ba, is 36.4 barn. The specific activity of the radionuclide can reach 13 Ci/g Ba. Methods of radioactive standardization of 133Ba by measuring either the Kx-γ coincidences in limited solid angles or the 4π(x,e -)-γ coincidences are described. Using different Ge(Li) detectors the relative γ-ray intensities in the decay of 133Ba were measured with high accuracy. (author)