tailieunhanh - Critical concentration of the exotic nuclei in the 232Th chain for the alpha analysts

The results show that most of decay half-lives are in consistent with those obtained from the NuDat data except for the multi-decay-mode isotopes. However, there is a large variation in the average values, 15% - 95% (in decimal logarithmic scale), of the half-lives evaluated by different formulae, that consequently leads to large decay constants deviations of 1% — 120% from the average values. From these results, we confirmed that the large radioactivity uncertainty because of the half-life deviations should be concerned for the preparation of the environmental samples when using alpha spectrometers. By assuming an efficiency of 100%, we found that the critical concentration for the alpha analysts of the 232Th nucleus is in a range of − µ g/(l or kg) in the samples. | Critical concentration of the exotic nuclei in the 232Th chain for the alpha analysts