Purpose
The methods for the determination of \(^{235}\) U/ \(^{238}\) U atom ratio are usually laborious and expensive, such as the \(\alpha \) / \(\gamma \) spectrometry and mass spectroscopic techniques. This study proposes a less labor intensive method as the low-energy photon spectrometry technique with acceptable precision.
Methods
A methodology based on the low-energy photon spectrometry with a silicon drift detector (SDD) is developed for the determination of \(^{235}\) U/ \(^{238}\) U atom ratio of depleted uranium samples. The SDD is well suited for measuring low-energy photons emitted from thin uranium sample source with low self-absorption, and the \(^{235}\) U/ \(^{238}\) U atom ratio is determined by the X/ \(\gamma \) -ray analysis with little sample preparation.
Results
The low-energy photon spectrometry employs a silicon drift detector to detect a thin piece of depleted uranium sample. The X/ \(\gamma \) -ray peaks at 13.0, 13.3, 13.56, 15.6, 16.2, 16.78, 17.17 and 19.58 keV are detected and analysed. By solving the equation of the peak net areas, the \(^{235}\) U/ \(^{238}\) U atom ratio is determined with the standard uncertainty less than 10.7%. The result is well consistent with the data obtained by the ICP-MS method.
Conclusion
The low-energy photon spectrometry with a silicon drift detector (SDD) is proved to be capable for the determination of \(^{235}\) U/ \(^{238}\) U atom ratio by comparing with the mass spectroscopic technique result. The advantages of this method are that very little sample preparation is required and the analysis is non-destructive. To improve the accuracy of the method, the nuclear databases for X/ \(\gamma \) -ray of \(^{235}\) U/ \(^{238}\) U chains should be complemented in future.
