相对效率法同位素丰度分析的研究

Analyzing isotopic abundance by method of relative efficiency

介绍了应用高纯锗探测器测量 γ谱分析同位素丰度的一种方法。该方法采用了探测器的相对效率的概念 ,在不对探测器进行刻度的情况下 ,通过测量样品中某一个核素的多条 γ射线 ,建立在这些 γ射线的能量范围内探测器的相对效率曲线 ,分析样品中其他核素的相对活度。实验测量了钚的 γ谱 ,利用 2 39Pu的多条 γ射线计算相对效率并分析其他钚同位素的丰度和镅钚比。

Traditional analysis of isotopic abundance should be fulfilled by mass spectrometer, but in some cases it can analyzed by HPGe γ spectroscopy when the isotope is radioactive. Generally,the HPGe detector must be calibrated before it is used to determine isotopic radioactivity in a sample. Since isotopic abundance is figured by relative activities, relative efficiency, which is calculated by one of the nuclides emitted more than one γ ray in a sample, can be used instead of efficiency of the detector. So the measured spectrum is used to figure out the relative efficiency firstly, and then to analyze isotopic abundance.