Colle Jean-Yves, Naji Mohamed, Sierig Mark, Manara Dario
European Commission, Joint Research Centre (JRC);
European Commission, Joint Research Centre (JRC).
J Vis Exp. 2017 Apr 12(122):54889. doi: 10.3791/54889.
A novel approach for the Raman measurement of nuclear materials is reported in this paper. It consists of the enclosure of the radioactive sample in a tight capsule that isolates the material from the atmosphere. The capsule can optionally be filled with a chosen gas pressurized up to 20 bars. The micro-Raman measurement is performed through an optical-grade quartz window. This technique permits accurate Raman measurements with no need for the spectrometer to be enclosed in an alpha-tight containment. It therefore allows the use of all options of the Raman spectrometer, like multi-wavelength laser excitation, different polarizations, and single or triple spectrometer modes. Some examples of measurements are shown and discussed. First, some spectral features of a highly radioactive americium oxide sample (AmO2) are presented. Then, we report the Raman spectra of neptunium oxide (NpO2) samples, the interpretation of which is greatly improved by employing three different excitation wavelengths, O doping, and a triple mode configuration to measure the anti-stokes Raman lines. This last feature also allows the estimation of the sample surface temperature. Finally, data that were measured on a sample from Chernobyl lava, where phases are identified by Raman mapping, are shown.
本文报道了一种用于核材料拉曼测量的新方法。它包括将放射性样品封装在一个紧密的胶囊中，使材料与大气隔离。该胶囊可选择性地填充一种压力高达20巴的选定气体。微拉曼测量通过光学级石英窗口进行。该技术允许进行精确的拉曼测量，而无需将光谱仪封闭在防α泄漏的容器中。因此，它允许使用拉曼光谱仪的所有选项，如多波长激光激发、不同偏振以及单光谱仪或三光谱仪模式。展示并讨论了一些测量示例。首先，给出了高放射性氧化镅样品（AmO₂）的一些光谱特征。然后，我们报告了氧化镎（NpO₂）样品的拉曼光谱，通过采用三种不同的激发波长、O掺杂以及三光谱仪模式来测量反斯托克斯拉曼线，对其光谱的解读有了很大改进。这最后一个特性还允许估计样品表面温度。最后，展示了在切尔诺贝利熔岩样品上测得的数据，其中通过拉曼映射确定了物相。
