放射化 分析法에 의한 土壤 및 岩石試料의 核種調査

Qualitative Analysis of Solid Samples and Rock Samples by Neutron Activation Analysts

中性子 放射化 分析法(NAA)은 일정 시간동간 未知의 試料를 熱中性子로 熙射시킨 후 試料가 放出하는 放射能을 測定하여 試料를 分析하는 方法이다. 化學的 元素 (n, r)反應의 結果로 生成된 放射性 核種으로 부터 特性放射能을 測定하여 分析할 수 있다. 이 實驗에 使用된 測定裝置는 multichannel analyzer (CANBERRA 90 series, ORTEC 7050 model)와 Ge(Li) 半導體 檢出器를 使用했으며, 熱中性子 線源으로서 原子爐를 利用했다. 實驗結果, (1) 土壤試料에는 ??⁴Cu, ¹⁴??La, ????Mn, ³¹Si, ²⁴Na, ⁴²K, ²??Al, ??²Br, ????Co, ????Co, ????Co, ²????Ra, ¹????Au, ????Tc, ²²??Th, ¹³¹I, ²²³Pa, ¹????Tb, ¹??¹Tb, ¹????Dy, ¹³??Ba. 등이 存在하고 있으며, (2) 岩石試料 1 g 중에는 우라늄 4.12 ± 0.09㎎ 과 토륨 0.15 ± 0.01㎎이 포함되어 있다. 이 中性子 放射化 分析法은 극히 적은 量의 試料를 定量하거나 定性分析하는데 매우 유용한 放法이다.

Neutron Activation Analysis(NAA) is an extremely powerful analysis technique, in which an unknown sample is bombarded with thermal neutrons for appropriately chosen lengths of time. The chemical elements are identified and assayed after irradiation by measurement of characteristic radiation emitted from radionuclides formed in the(n,r) reaction. A counting system for neutron activation analysis is a multichannel analyzer with Ge(Li) detector (CANBERRA 90 series, ORTEC 7050 model). In a way, the neuclear reactor is used as a source of thermal neutrons. In this study, 1)The following elements are found in soil samples; ??⁴Cu, ¹⁴??La, ????Mn, ³¹Si, ²⁴Na, ⁴²K, ²??Al, ??²Br, ????Co, ????Co, ????Co, ²????Ra, ¹????Au, ????Tc, ²²??Th, ¹³¹I, ²²³Pa, ¹????Tb, ¹??¹Tb, ¹????Dy, ¹³??Ba. 2)The following amount uranium 4.12 ± 0.09㎎ and thorjum 0.15 ± 0.01㎎ are detected in lg of rock samples. This technique is suitable for the micro-qualitative and quantitative anaysis.