107Pd是长寿命裂变产物核素,有较大的分析价值。由于Pd的高电离电位(8.33 eV),在热表面电离质谱(TIMS)的离子源内电离效率很低,因此,采用热表面电离质谱技术测量Pd的难度非常高。本文选择了三种激发剂对Pd的热电离质谱方法进行了改进,...107Pd是长寿命裂变产物核素,有较大的分析价值。由于Pd的高电离电位(8.33 eV),在热表面电离质谱(TIMS)的离子源内电离效率很低,因此,采用热表面电离质谱技术测量Pd的难度非常高。本文选择了三种激发剂对Pd的热电离质谱方法进行了改进,对比了TaF5、胶体石墨和磷酸硅胶等激发剂对Pd的质谱效率的影响。TaF5的效果要差于其他两种激发剂,胶体石墨和磷酸硅胶则效果相当,质谱效率在10–7量级。采用舟型带比单带的质谱效率提高了2倍以上,最高质谱效率达到4.55×10–7。测定了2 g Pd样品的同位素比值,采用磷酸硅胶为激发剂,106Pd/108Pd测量平均值与标称值偏差为0.36%,测量相对标准偏差为0.14%(n=10),证明对于微克量级Pd样品的同位素比值测量可以获得较好的准确度与精度。展开更多
The data of uranium isotope abundance ratios measured by thermal ionization mass spectrometer MAT-261 were analyzed in the three aspects including distribution function, correlation and uncertainty. The measurement da...The data of uranium isotope abundance ratios measured by thermal ionization mass spectrometer MAT-261 were analyzed in the three aspects including distribution function, correlation and uncertainty. The measurement data were confirmed to be normal distribution. Uncertainty and correlation of the isotope abundance ratios measured by MAT-261 in the certified uranium sample were investigated. The conclusion obtained indicated that, the correlation only between abundance ratios R5/8 and R4/8 is strong, but the others is weak for the enriched uranium sample; For the natural uranium sample, the correlation among all abundance ratios is weak. On this base, the uncertainty of all abundance ratios measured by MAT-261 had been evaluated.展开更多
文摘107Pd是长寿命裂变产物核素,有较大的分析价值。由于Pd的高电离电位(8.33 eV),在热表面电离质谱(TIMS)的离子源内电离效率很低,因此,采用热表面电离质谱技术测量Pd的难度非常高。本文选择了三种激发剂对Pd的热电离质谱方法进行了改进,对比了TaF5、胶体石墨和磷酸硅胶等激发剂对Pd的质谱效率的影响。TaF5的效果要差于其他两种激发剂,胶体石墨和磷酸硅胶则效果相当,质谱效率在10–7量级。采用舟型带比单带的质谱效率提高了2倍以上,最高质谱效率达到4.55×10–7。测定了2 g Pd样品的同位素比值,采用磷酸硅胶为激发剂,106Pd/108Pd测量平均值与标称值偏差为0.36%,测量相对标准偏差为0.14%(n=10),证明对于微克量级Pd样品的同位素比值测量可以获得较好的准确度与精度。
文摘The data of uranium isotope abundance ratios measured by thermal ionization mass spectrometer MAT-261 were analyzed in the three aspects including distribution function, correlation and uncertainty. The measurement data were confirmed to be normal distribution. Uncertainty and correlation of the isotope abundance ratios measured by MAT-261 in the certified uranium sample were investigated. The conclusion obtained indicated that, the correlation only between abundance ratios R5/8 and R4/8 is strong, but the others is weak for the enriched uranium sample; For the natural uranium sample, the correlation among all abundance ratios is weak. On this base, the uncertainty of all abundance ratios measured by MAT-261 had been evaluated.
