Activation analysis with a 45 MeV electron linear accelerator

Activation analysis of several materials was performed with the Hokkaido University 45 MeV Electron Linear Accelerator. The combination of a lead target and a paraffine moderator was utilized to produce the thermal neutron for the radio-activation. Sixteen samples of metallic and inorganic materials were irradiated, and the γ-ray spectra were measured with a well-type NaI (Tl) scintillation counter. In all cases, the build-up curves of each activated nuclides were given fairly well by the modified exponential formula. Since the neutron flux produced by the linear accelerator is very low in comparison with that of a nuclear reactor, remarkable activation was obtained for a limited number of nuclides which had high activation cross section and/or short half lives. However, rather high sensitivity and accuracy were obtained in the quantitative analysis of some elements in practical materials such as hafnium in zirconium metals, manganese in iron, steels and iron compounds, and molybdenum and other elements in austenitic stainless steels. (auth.)