高钚含量样品中α能谱法分析~(237)Np的可行性研究

通过对244 Cm的α实验谱进行拟合得到单能峰的峰形参数,采用随机抽样技术表征谱计数的统计涨落,建立了一种模拟半导体α能谱的方法。利用该方法模拟238Pu和243Am的α能谱,与实验谱基本吻合,证明了方法的可靠性。在此基础上,研究了239Pu对237Np的α能峰的影响,结果表明,当239Pu与237Np的活度比A(239Pu)/A(237Np)≤10时,通过解谱得到的A(239Pu)/A(237Np)与设定值的相对偏差≤2.0%。对于A(239Pu)/A(237Np)约为3 000的样品,如果对钚的去污系数达到300以上,则可由α能谱法测量样品中的237 Np。

Feasibility Study on α Spectrometry Analysis of 237Np in Sample with High 239Pu Content

The peak shape parameters were obtained by fitting ²⁴⁴Cm α experiment spectra. The fluctuation of counts was characterized by random sampling, and a simulation method of α spectra was established. The method was verified by comparing the simulation spectra and the experiment spectra of ²³⁸Pu and ²⁴³Am. The effects of ²³⁹Pu on ²³⁷Np were analyzed. The results indicate that the relative deviation between the activity -ratio of ²³⁹Pu and ²³⁷Np (A(²³⁹Pu)/A(²³⁷Np)) obtained by spectra analysis and the preassigned value is ≤2.0% if the A(²³⁹Pu)/A(²³⁷Np) is ≤10. For the sample with A(²³⁹Pu)/A(²³⁷Np) of about 3000, ²³⁷Np can be measured with α spectrometry if the decontamination factor of ²³⁹Pu reaches to 300.