検索対象:     
報告書番号:
※ 半角英数字
 年 ~ 
 年

Ultra-trace analysis of plutonium by thermal ionization mass spectrometry with a continuous heating technique without chemical separation

連続昇温法を用いた表面電離質量分析法による化学分離を伴わない極微量プルトニウム分析

Lee, C.-G.*; 鈴木 大輔; 江坂 文孝; 間柄 正明; Song, K.*

Lee, C.-G.*; Suzuki, Daisuke; Esaka, Fumitaka; Magara, Masaaki; Song, K.*

連続昇温法による表面電離質量分析法は極微量のウランの同位体比測定に有効であることが知られている。本研究では、プルトニウム(Pu, SRM947)を用いて連続昇温法による表面電離質量分析法の分析性能について調べた。fgレベルのPu溶液試料を用いて同位体比の正確さと精密さの蒸発フィラメントの加熱速度依存性を検討した。0.1-1000fg範囲の試料において蒸発フィラメント加熱速度を100mA/minから250mA/minまで変えた結果、同位体比の正確さ及び精密さにはほとんど影響しなかった。試料量が70fgまではPuのすべての同位体比が測定された。また、試料量0.1fg(0.2$$mu$$mのPuO$$_{2}$$粒子の質量に相当)までは$$^{240}$$Pu/$$^{239}$$Puが測定された。さらに、$$^{239}$$Puの信号は0.03fgまで検出でき、これは3$$sigma$$法により評価すると$$^{239}$$Puの検出限界は0.006fgになる。本研究では、$$^{241}$$Puの崩壊により生成される$$^{241}$$Amと$$^{241}$$Puは蒸発フィラメントの温度差により分別できた。その結果、連続昇温法による表面電離質量分析法では$$^{240}$$Pu/$$^{239}$$Puと$$^{242}$$Pu/$$^{239}$$Puだけではなく$$^{241}$$Pu/$$^{239}$$Puの比も化学分離なしで測定することができた。

Thermal ionization mass spectrometry (TIMS) with a continuous heating technique is known as an effective method for measuring the isotope ratio in trace amounts of uranium. In this study, the analytical performance of thermal ionization mass spectrometry with a continuous heating technique was investigated using a standard plutonium solution (SRM 947). The influence of the heating rate of the evaporation filament on the precision and accuracy of the isotope ratios was examined using a plutonium solution sample at the fg level. Changing the heating rate of the evaporation filament on samples ranging from 0.1 fg to 1000 fg revealed that the influence of the heating rate on the precision and accuracy of the isotope ratios was slight around the heating rate range of 100 to 250 mA/min. All of the isotope ratios of plutonium (SRM 947), $$^{238}$$Pu/$$^{239}$$Pu, $$^{240}$$Pu/$$^{239}$$Pu, $$^{241}$$Pu/$$^{239}$$Pu and $$^{242}$$Pu/$$^{239}$$Pu, were measured down to sample amounts of 70 fg. The ratio of $$^{240}$$Pu/$$^{239}$$Pu was measured down to a sample amount of 0.1 fg, which corresponds to a PuO$$_{2}$$ particle with a diameter of 0.2 $$mu$$m. Moreover, the signals of $$^{239}$$Pu could be detected with a sample amount of 0.03 fg, which corresponds to the detection limit of $$^{239}$$Pu of 0.006 fg as estimated by the 3 $$sigma$$ criterion. $$^{241}$$Pu and $$^{241}$$Am formed by the decay of $$^{241}$$Pu could be discriminated owing to the difference in the evaporation temperature. As a result, $$^{241}$$Pu/$$^{239}$$Pu as well as $$^{240}$$Pu/$$^{239}$$Pu and $$^{242}$$Pu/$$^{239}$$Pu in plutonium samples could be measured by TIMS with a continuous heating technique and without any chemical separation processes.

Access

:

- Accesses

InCites™

:

パーセンタイル:58.47

分野:Chemistry, Analytical

Altmetrics

:

[CLARIVATE ANALYTICS], [WEB OF SCIENCE], [HIGHLY CITED PAPER & CUP LOGO] and [HOT PAPER & FIRE LOGO] are trademarks of Clarivate Analytics, and/or its affiliated company or companies, and used herein by permission and/or license.