活化分析（activation analysis）

一种物理分析技术，通常可用来检测以毫克量(或更少)出现在试验样品中的许多元 素。在中子活化分析中，样品容易受到核反应器中热中子通量的影响，样品 中的某些中子被核素俘获形成原子序相同，但质量数较高的核素。这新形 成的核素辐射伽玛射线，可借助伽玛射线波谱仪利用辐射的伽玛射线来识 别存在的元素。另外这种技术也可利用带电粒子如质子或a 粒子而采用放射性分析。

Neutron activation analysis (NAA) is a nuclear process used for determining the concentrations of elements in a vast amount of materials. NAA allows discrete sampling of elements as it disregards the chemical form of a sample, and focuses solely on its nucleus. The method is based on neutron activation and therefore requires a source of neutrons. The sample is bombarded with neutrons, causing the elements to form radioactive isotopes. The radioactive emissions and radioactive decay paths for each element are well known. Using this information, it is possible to study spectra of the emissions of the radioactive sample, and determine the concentrations of the elements within it. A particular advantage of this technique is that it does not destroy the sample, and thus has been used for analysis of works of art and historical artifacts. NAA can also be used to determine the activity of a radioactive sample.