高钚含量样品中α能谱法分析<sup>237</sup>Np的可行性研究

高钚含量样品中α能谱法分析²³⁷Np的可行性研究

摘要: 通过对²⁴⁴Cm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3000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²³⁷Np。

Abstract: 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.