Determination of the half-life of ⁹¹Sr in uranium sample bombarded by 14.8 MeV neutron

Abstract

Purpose

Due to the few reports on the ⁹¹Sr half-life previously, the accuracy and uncertainty of the results are difficult to meet the requirements such as calculating the cross section and the fission yields of ²³⁵U, ²³⁸U, and ²³⁹Pu. To solve the discrepancy of ⁹¹Sr half-life in existing experimental data, the half-life of ⁹¹Sr was measured in this work, and the uncertainty was discussed in detail.

Method

The measurements were performed by the activation method implemented for the uranium sample using the K-400 neutron generator at the Chinese Academy of Engineering Physics (CAEP). The half-life of ⁹¹Sr was measured by γ-ray spectrometry using the high-resolution High Purity Germanium (HPGe) Detector.

Results

Through exponential function fitting and a detailed discussion of the uncertainty evaluation, the half-life of ⁹¹Sr in the present work was determined to be 9.65 ± 0.30 h, which was consistent with the values reported previously and the uncertainty was reduced greatly, however, the uncertainty assessment of the latter was barely documented.

Conclusions

In this work, a more accurate measurement of the ⁹¹Sr half-life is provided, as well as the uncertainty is discussed in detail. This result will provide essential information for applications using an activation method, such as the calculation of fission yields of ²³⁵U, ²³⁸U, and ²³⁹Pu.