CAJ | 학술논문

重金属污染越来越受到人们的关注，迫切需要开发具有高精度的原位检测技术。瞬发伽玛中子活化分析（PGNAA）技术具有原位、无损、快速等优点而被广泛应用于重金属测量，但由于目前原位检测装置中使用的中子源通量相对较低，因此对一些重金属元素分析精度相对不高。为提高测量精度，直接利用PG-NAA技术中的瞬发特征γ射线充当传统X荧光光谱分析的激发源，来激发重金属元素的特征X射线荧光（XRF）信息，提出了一种PGNAA-XRF联合检测水溶液中重金属元素的方法，并设计了一套由BGO和带铍窗的NaI组成的双探测器联合检测装置，分别用来探测PGNAA中瞬发特征γ射线和特征X荧光信息。通过MCNP分别模拟研究了Cr ，Cd ，Hg和Pb的浓度（ci ）对瞬发特征γ射线强度（Iγ）和特征X荧光强度（IX ）的影响，模拟结果表明该装置中Cr ，Cd ，Hg和Pb元素的 Iγ和 IX 均与 ci 成良好的线性关系，并建立了联合检测方法的经验公式。比较重金属元素特征X射线荧光发现，该联合方法对 Hg和Pb等高原子序数重金属的检测较灵敏，最后计算得到该装置对Hg和Pb等重金属元素的检测限分别为17.4和24.2 mg · kg -1。
중금속오염월래월수도인문적관주，박절수요개발구유고정도적원위검측기술。순발가마중자활화분석（PGNAA）기술구유원위、무손、쾌속등우점이피엄범응용우중금속측량，단유우목전원위검측장치중사용적중자원통량상대교저，인차대일사중금속원소분석정도상대불고。위제고측량정도，직접이용PG-NAA기술중적순발특정γ사선충당전통X형광광보분석적격발원，래격발중금속원소적특정X사선형광（XRF）신식，제출료일충PGNAA-XRF연합검측수용액중중금속원소적방법，병설계료일투유BGO화대피창적NaI조성적쌍탐측기연합검측장치，분별용래탐측PGNAA중순발특정γ사선화특정X형광신식。통과MCNP분별모의연구료Cr ，Cd ，Hg화Pb적농도（ci ）대순발특정γ사선강도（Iγ）화특정X형광강도（IX ）적영향，모의결과표명해장치중Cr ，Cd ，Hg화Pb원소적 Iγ화 IX 균여 ci 성량호적선성관계，병건립료연합검측방법적경험공식。비교중금속원소특정X사선형광발현，해연합방법대 Hg화Pb등고원자서수중금속적검측교령민，최후계산득도해장치대Hg화Pb등중금속원소적검측한분별위17.4화24.2 mg · kg -1。
In the present paper ,a new combined detection method was proposed using prompt gamma neutron activation analysis (PGNAA) and characteristic X-ray fluorescence to improve the heavy metals measurement accuracy for in-situ environmental wa-ter rejects analysis by PGNAA technology .Especially ,the characteristic X-ray fluorescence (XRF) of heavy metals is induced by prompt gamma-ray directly instead of the traditional excitation sources .Thus ,a combined measurement facility with an 241 Am-Be neutron source ,a BGO detector and a NaI-Be detector was developed to analyze the pollutants in water .The two detectors were respectively used to record prompt gamma-ray and characteristic X-ray fluorescence of heavy metals .The prompt gamma-ray intensity (Iγ) and characteristic X-ray fluorescence intensity (IX ) was determined by MCNP calculations for different concen-tration (ci ) of chromium (Cr) ,cadmium (Cd) ,mercury (Hg) and lead (Pb) ,respectively .The simulation results showed that there was a good linear relationship between Iγ ,IX and (ci) ,respectively .The empirical formula of combined detection method was given based on the above calculations .It was found that the combined detection method was more sensitive for high atomic number heavy metals like Hg and Pb measurement than low atomic number like Cr and Cd by comparing and analyzing Iγ and IX . The limits of detection for Hg and Pb by the combined measurement instrument were 17.4 and 24.2 mg · kg -1 ,respectively .