瞬发γ中子活化分析测定微量硼

Determination of Boron by Prompt Gamma-ray Neutron Activation Analysis

利用中国先进研究堆(CARR)建立的瞬发γ中子活化分析系统(CARR-PGNAA),首次开展了高温合金标准物质(SRM1250和GH4169)中的B含量无损分析。研究发现,B的特征γ峰(478 keV)由于多普勒效应存在近20 keV的展宽,且由于样品基体元素的干扰导致B峰极不规则,两者均会影响B含量的精准定量分析。因此,初步通过扣除主要干扰元素Ni和Co对B峰产生的影响来矫正干扰峰并拟合B峰,获得高温合金中B含量与计数率之间的线性关系。分析结果表明,扣除干扰后B特征峰计数率随着其含量呈线性增加,线性拟合度趋近于1,进一步验证了CARR-PGNAA系统的可行性,为B的精准定量奠定了基础。

The B concentration of high-temperature alloy reference materials(i.e.,SRM1250 and GH4169)were firstly analyzed using promptγ-ray neutron activation analysis(PGNAA)system at China Advanced Research Reactor(CARR)established by China Institute of Atomic Energy(CIAE).It is worth mentioning here that the B peak(478 keV)is very wide(nearly 20 keV)as a result of the influence of Doppler effect and extremely irregular due to the interference elements of the sample,both of which will affect the accurate quantitative analysis of the B concentration.Therefore,it is necessary to carefully analyze and process the measured promptγspectra of B element.To solve these problems and accurately determine the B concentration,in this work,the linear relationship between the concentration in the high-temperature alloy and the count rate was obtained by subtracting the effects of the major interference element Ni and Co to correct the interference peaks,and further fitting the boron peak.The results demonstrated that the count rate of characteristic peak of B increased linearly with its mass,which further verified the feasibility of the PGNAA system at CARR.The system and method established in this work can continue to promote the development of high-accuracy analysis technology for trace amounts of B in high-temperature alloy materials.