钛中氢同位素的热脱附谱定量分析研究

Quantitative Analysis of Hydrogen Isotopes in Titanium Using Thermal Desorption Spectroscopy

摘要:

钛作为一种典型的储氢材料，在氢能材料以及氘氚聚变中子源等领域具有重要的用途；氢同位素在钛中的含量和分布会影响钛的结构以及使用性能。钛中氢同位素含量的常规测定方法有压力-体积法、称重法和热重法等；同这些常规方法相比，热脱附谱方法(Thermal desorption spectroscopy, TDS)既可以获得氢同位素含量信息，还可以区分氢、氘同位素种类信息，并且可揭示氢同位素原子在晶格中的占位信息。本工作通过优化钛的吸氢工艺，成功制备了不同氢氘含量的氢/氘化钛样品；结合X射线衍射(X-ray diffraction, XRD)分析，给出了钛吸氢前后的晶体结构变化。利用课题组发展的热脱附谱技术，通过标准漏孔标定质谱仪的离子流信号强度，实现了钛中氢同位素脱附量的定量测定；TDS法测量结果与压力-体积法测量值之间的绝对误差小于6%。研究结果可为氢能、核能及核技术领域材料中氢同位素含量的准确测量提供有益参考。

Abstract:

As a typical hydrogen storage material, titanium has an important application on hydrogen energy materials and deuterium-tritium fusion neutron source. The various contents and distribution of hydrogen isotopes in titanium will affect the structure and properties of titanium in many ways. The conventional quantitative determination methods of hydrogen isotope content in titanium include pressure-volume method, weighing method and thermogravimetric method, etc. Compared with these conventional methods, the thermal desorption spectroscopy (TDS) method can not only obtain hydrogen isotope contents, but also distinguish between hydrogen and deuterium, and can reveal the position information of hydrogen isotope atoms in the crystal lattice. In this research, by optimizing the hydrogen absorption process of titanium, titanium hydrogenated/deuteride samples with different hydrogen and deuterium contents were successfully prepared. Combined with X-ray diffraction (XRD) analysis, the crystal structure changes of titanium before and after hydrogen absorption are given. Using the TDS technology developed by our research group, the ion current signal intensity of the mass spectrometer was calibrated through a standard leakage, and the quantitative analysis of the amount of hydrogen isotope desorption in titanium was realized. The absolute error between the TDS measurement result and the pressure-volume method measurement value is less than 6%. The total contents of hydrogen and deuterium desorbed in the sample were calculated. The results provide a useful reference for the accurate measurement of hydrogen isotope content in materials in the field of hydrogen energy, nuclear energy and nuclear technology.