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Donohue, D.*; Ciurapinski, A.*; Cliff, J.*; R
denauer, F.*; Kuno, Takehiko; Poths, J.*
Applied Surface Science, 255(5, Part 2), p.2561 - 2568, 2008/12
Times Cited Count：15 Percentile：54.78(Chemistry, Physical)A combination of micro-analytical techniques was used for the characterization of spherical particles in the size range 9-12
m as a part of nuclear safeguards verification activities pursuant to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). The particles were removed from cotton swipe samples taken in a nuclear facility under safeguards and examined first by scanning electron microscopy combined with energy-dispersive X-ray spectrometry (SEM-EDX). Particles of interest were then relocated under an optical microscope and manipulated. One such particle was subjected to destructive analysis by secondary ion mass spectrometry (SIMS) in order to determine if uranium was present in the core of the particle. A second particle was examined using focused ion beam (FIB) etching to allow an examination of the interior by SEM-EDX. The particle manipulation and relocation techniques presented here allow the sequential examination of a single particle of interest by a combination of analytical techniques, thus yielding surface morphological, elemental, isotopic and depth-profiling information. The objective of these investigations is to provide assurance of the absence of clandestine or undeclared nuclear activities in States coming under comprehensive safeguards obligations.
Shinonaga, Taeko*; Esaka, Fumitaka; Magara, Masaaki; Klose, D.*; Donohue, D.*
Spectrochimica Acta, Part B, 63(11), p.1324 - 1328, 2008/11
Times Cited Count：38 Percentile：84.81(Spectroscopy)The isotopic composition of single uranium and plutonium particles was measured with an inductively coupled plasma mass spectrometer (ICP-MS) and a thermal ionization mass spectrometer (TIMS). The particles prepared on a carbon planchet were first analyzed with an energy dispersive X-ray spectrometer (EDX) attached to a scanning electron microscope (SEM) and then transferred on to a silicon wafer using a manipulator. The particle on the silicon wafer was dissolved with nitric acid and the isotopic ratios of U and Pu were measured with ICP-MS and TIMS. The results obtained by both methods showed good agreement with the certified values within the expected uncertainty. The measurement uncertainties obtained in this study were similar for both mass spectrometric methods. This study was performed to establish the method of particle analysis with SEM, EDX, the particle manipulation technique, and the measurement of isotope ratios of U and Pu in a single particle by mass spectrometry.
Shinonaga, Taeko*; Donohue, D.*; Klose, D.*; Kuno, Takehiko*; Kuno, Yusuke*; Esaka, Fumitaka; Esaka, Konomi; Magara, Masaaki; Sakurai, Satoshi; Usuda, Shigekazu
STI/PUB/1298 (CD-ROM), p.525 - 531, 2007/08
More precise, accurate and prompt analyses of uranium and plutonium in various types of environmental samples are increasingly requested from the Clean Laboratory Unit, Safeguards Analytical Laboratory of IAEA in recent years. Particles show unique information and up to now, the secondary ion mass spectrometry (SIMS) has been employed for the uranium and plutonium particle analysis. The SIMS that is the most rapid method for particle analysis has, however, disadvantages for the analysis of the minor isotopes like 
U and 
U, i.e., not precise enough. The SIMS measurement also has a difficulty on Pu determination because of the interference of U-based isobaric signals. In this study, a combination of techniques, picking-up particles by a manipulator attached to a scanning electron microscope (SEM), followed by uranium and plutonium chemical purification and measurement by an inductively coupled plasma mass spectrometer (ICP-MS) and thermal ionization mass spectrometer (TIMS), was demonstrated for particle analysis using standard materials (NBS U500 and NBS 947) to develop a particle-chemical analysis.
