Precise determination of the absolute intensities of the gamma-ray lines of 235U and some 238U daughters

The intensities of some gamma-ray lines emitted from 234Th and 234Pa are usually used to estimate the concentrations of 238U in different environmental samples. However, the absolute intensity values currently available for some gamma-ray lines which are used for determination of these concentrations seem to be inaccurate and include some discrepancies. In the present work, the absolute intensity values for some gamma-ray lines of 235U, 234Th and 234Pa have been studied and precisely evaluated using a hyper pure germanium high-resolution gamma spectrometer.