A NanoSIMS 50 L Investigation into Improving the Precision and Accuracy of the <sup>235</sup>U/<sup>238</sup>U Ratio Determination by Using the Molecular <sup>235</sup>U<sup>16</sup>O and <sup>238</sup>U<sup>16</sup>O Secondary Ions
A NanoSIMS 50 L was used to study the relationship between the <sup>235</sup>U/<sup>238</sup>U atomic and <sup>235</sup>U<sup>16</sup>O/<sup>238</sup>U<sup>16</sup>O molecular uranium isotope ratios determined from a variety of...
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2019-05-01
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Article |
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DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
N. Alex Zirakparvar Cole R. Hexel Andrew J. Miskowiec Julie B. Smith Michael W. Ambrogio Douglas C. Duckworth Roger Kapsimalis Brian W. Ticknor |
spellingShingle |
N. Alex Zirakparvar Cole R. Hexel Andrew J. Miskowiec Julie B. Smith Michael W. Ambrogio Douglas C. Duckworth Roger Kapsimalis Brian W. Ticknor A NanoSIMS 50 L Investigation into Improving the Precision and Accuracy of the <sup>235</sup>U/<sup>238</sup>U Ratio Determination by Using the Molecular <sup>235</sup>U<sup>16</sup>O and <sup>238</sup>U<sup>16</sup>O Secondary Ions Minerals NanoSIMS uranium isotope ratio mass spectrometry secondary ion matrix effect |
author_facet |
N. Alex Zirakparvar Cole R. Hexel Andrew J. Miskowiec Julie B. Smith Michael W. Ambrogio Douglas C. Duckworth Roger Kapsimalis Brian W. Ticknor |
author_sort |
N. Alex Zirakparvar |
title |
A NanoSIMS 50 L Investigation into Improving the Precision and Accuracy of the <sup>235</sup>U/<sup>238</sup>U Ratio Determination by Using the Molecular <sup>235</sup>U<sup>16</sup>O and <sup>238</sup>U<sup>16</sup>O Secondary Ions |
title_short |
A NanoSIMS 50 L Investigation into Improving the Precision and Accuracy of the <sup>235</sup>U/<sup>238</sup>U Ratio Determination by Using the Molecular <sup>235</sup>U<sup>16</sup>O and <sup>238</sup>U<sup>16</sup>O Secondary Ions |
title_full |
A NanoSIMS 50 L Investigation into Improving the Precision and Accuracy of the <sup>235</sup>U/<sup>238</sup>U Ratio Determination by Using the Molecular <sup>235</sup>U<sup>16</sup>O and <sup>238</sup>U<sup>16</sup>O Secondary Ions |
title_fullStr |
A NanoSIMS 50 L Investigation into Improving the Precision and Accuracy of the <sup>235</sup>U/<sup>238</sup>U Ratio Determination by Using the Molecular <sup>235</sup>U<sup>16</sup>O and <sup>238</sup>U<sup>16</sup>O Secondary Ions |
title_full_unstemmed |
A NanoSIMS 50 L Investigation into Improving the Precision and Accuracy of the <sup>235</sup>U/<sup>238</sup>U Ratio Determination by Using the Molecular <sup>235</sup>U<sup>16</sup>O and <sup>238</sup>U<sup>16</sup>O Secondary Ions |
title_sort |
nanosims 50 l investigation into improving the precision and accuracy of the <sup>235</sup>u/<sup>238</sup>u ratio determination by using the molecular <sup>235</sup>u<sup>16</sup>o and <sup>238</sup>u<sup>16</sup>o secondary ions |
publisher |
MDPI AG |
series |
Minerals |
issn |
2075-163X |
publishDate |
2019-05-01 |
description |
A NanoSIMS 50 L was used to study the relationship between the <sup>235</sup>U/<sup>238</sup>U atomic and <sup>235</sup>U<sup>16</sup>O/<sup>238</sup>U<sup>16</sup>O molecular uranium isotope ratios determined from a variety of uranium compounds (UO<sub>2</sub>, UO<sub>2</sub>F<sub>2</sub>, UO<sub>3</sub>, UO<sub>2</sub>(NO<sub>3</sub>)<sub>2</sub>·6(H<sub>2</sub>O), and UF<sub>4</sub>) and silicates (NIST-610 glass and the Plesovice zircon reference materials, both containing µg/g uranium). Because there is typically a greater abundance of <sup>235</sup>U<sup>16</sup>O<sup>+</sup> and <sup>238</sup>U<sup>16</sup>O<sup>+</sup> molecular secondary ions than <sup>235</sup>U<sup>+</sup> and <sup>238</sup>U<sup>+</sup> atomic ions when uranium-bearing materials are sputtered with an oxygen primary ion beam, the goal was to understand whether use of <sup>235</sup>U<sup>16</sup>O/<sup>238</sup>U<sup>16</sup>O has the potential for improved accuracy and precision when compared to the <sup>235</sup>U/<sup>238</sup>U ratio. The UO<sub>2</sub> and silicate reference materials showed the greatest potential for improved accuracy and precision through use of the <sup>235</sup>U<sup>16</sup>O/<sup>238</sup>U<sup>16</sup>O ratio as compared to the <sup>235</sup>U/<sup>238</sup>U ratio. For the UO<sub>2</sub>, which was investigated at a variety of primary beam currents, and the silicate reference materials, which were only investigated using a single primary beam current, this improvement was especially pronounced at low <sup>235</sup>U<sup>+</sup> count rates. In contrast, comparison of the <sup>235</sup>U<sup>16</sup>O/<sup>238</sup>U<sup>16</sup>O ratio versus the <sup>235</sup>U/<sup>238</sup>U ratio from the other uranium compounds clearly indicates that the <sup>235</sup>U<sup>16</sup>O/<sup>238</sup>U<sup>16</sup>O ratio results in worse precision and accuracy. This behavior is based on the observation that the atomic (<sup>235</sup>U<sup>+</sup> and <sup>238</sup>U<sup>+</sup>) to molecular (<sup>235</sup>U<sup>16</sup>O<sup>+</sup> and <sup>238</sup>U<sup>16</sup>O<sup>+</sup>) secondary ion production rates remain internally consistent within the UO<sub>2</sub> and silicate reference materials, whereas it is highly variable in the other uranium compounds. Efforts to understand the origin of this behavior suggest that irregular sample surface topography, and/or molecular interferences arising from the manner in which the UO<sub>2</sub>F<sub>2</sub>, UO<sub>3</sub>, UO<sub>2</sub>(NO<sub>3</sub>)<sub>2</sub>·6(H<sub>2</sub>O), and UF<sub>4</sub> were prepared, may be a major contributing factor to the inconsistent relationship between the observed atomic and molecular secondary ion yields. Overall, the results suggest that for certain bulk compositions, use of the <sup>235</sup>U<sup>16</sup>O/<sup>238</sup>U<sup>16</sup>O may be a viable approach to improving the precision and accuracy in situations where a relatively low <sup>235</sup>U<sup>+</sup> count rate is expected. |
topic |
NanoSIMS uranium isotope ratio mass spectrometry secondary ion matrix effect |
url |
https://www.mdpi.com/2075-163X/9/5/307 |
work_keys_str_mv |
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doaj-b369a132407048068aed1a53ecfb542e2020-11-25T03:27:03ZengMDPI AGMinerals2075-163X2019-05-019530710.3390/min9050307min9050307A NanoSIMS 50 L Investigation into Improving the Precision and Accuracy of the <sup>235</sup>U/<sup>238</sup>U Ratio Determination by Using the Molecular <sup>235</sup>U<sup>16</sup>O and <sup>238</sup>U<sup>16</sup>O Secondary IonsN. Alex Zirakparvar0Cole R. Hexel1Andrew J. Miskowiec2Julie B. Smith3Michael W. Ambrogio4Douglas C. Duckworth5Roger Kapsimalis6Brian W. Ticknor7Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37830, USAOak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37830, USAOak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37830, USAOak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37830, USAOak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37830, USAOak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37830, USAOak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37830, USAOak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37830, USAA NanoSIMS 50 L was used to study the relationship between the <sup>235</sup>U/<sup>238</sup>U atomic and <sup>235</sup>U<sup>16</sup>O/<sup>238</sup>U<sup>16</sup>O molecular uranium isotope ratios determined from a variety of uranium compounds (UO<sub>2</sub>, UO<sub>2</sub>F<sub>2</sub>, UO<sub>3</sub>, UO<sub>2</sub>(NO<sub>3</sub>)<sub>2</sub>·6(H<sub>2</sub>O), and UF<sub>4</sub>) and silicates (NIST-610 glass and the Plesovice zircon reference materials, both containing µg/g uranium). Because there is typically a greater abundance of <sup>235</sup>U<sup>16</sup>O<sup>+</sup> and <sup>238</sup>U<sup>16</sup>O<sup>+</sup> molecular secondary ions than <sup>235</sup>U<sup>+</sup> and <sup>238</sup>U<sup>+</sup> atomic ions when uranium-bearing materials are sputtered with an oxygen primary ion beam, the goal was to understand whether use of <sup>235</sup>U<sup>16</sup>O/<sup>238</sup>U<sup>16</sup>O has the potential for improved accuracy and precision when compared to the <sup>235</sup>U/<sup>238</sup>U ratio. The UO<sub>2</sub> and silicate reference materials showed the greatest potential for improved accuracy and precision through use of the <sup>235</sup>U<sup>16</sup>O/<sup>238</sup>U<sup>16</sup>O ratio as compared to the <sup>235</sup>U/<sup>238</sup>U ratio. For the UO<sub>2</sub>, which was investigated at a variety of primary beam currents, and the silicate reference materials, which were only investigated using a single primary beam current, this improvement was especially pronounced at low <sup>235</sup>U<sup>+</sup> count rates. In contrast, comparison of the <sup>235</sup>U<sup>16</sup>O/<sup>238</sup>U<sup>16</sup>O ratio versus the <sup>235</sup>U/<sup>238</sup>U ratio from the other uranium compounds clearly indicates that the <sup>235</sup>U<sup>16</sup>O/<sup>238</sup>U<sup>16</sup>O ratio results in worse precision and accuracy. This behavior is based on the observation that the atomic (<sup>235</sup>U<sup>+</sup> and <sup>238</sup>U<sup>+</sup>) to molecular (<sup>235</sup>U<sup>16</sup>O<sup>+</sup> and <sup>238</sup>U<sup>16</sup>O<sup>+</sup>) secondary ion production rates remain internally consistent within the UO<sub>2</sub> and silicate reference materials, whereas it is highly variable in the other uranium compounds. Efforts to understand the origin of this behavior suggest that irregular sample surface topography, and/or molecular interferences arising from the manner in which the UO<sub>2</sub>F<sub>2</sub>, UO<sub>3</sub>, UO<sub>2</sub>(NO<sub>3</sub>)<sub>2</sub>·6(H<sub>2</sub>O), and UF<sub>4</sub> were prepared, may be a major contributing factor to the inconsistent relationship between the observed atomic and molecular secondary ion yields. Overall, the results suggest that for certain bulk compositions, use of the <sup>235</sup>U<sup>16</sup>O/<sup>238</sup>U<sup>16</sup>O may be a viable approach to improving the precision and accuracy in situations where a relatively low <sup>235</sup>U<sup>+</sup> count rate is expected.https://www.mdpi.com/2075-163X/9/5/307NanoSIMSuraniumisotope ratio mass spectrometrysecondary ionmatrix effect |