Isotopic composition measurement on sub-picogram amounts of plutonium

Multiple ion counting determination of plutonium isotope ratios using multi-collector ICP-MS

“…Other studies results are summarised in Table 4 and include 240 Pu/ 239 Pu measurements by accelerator mass spectrometry (AMS), 7 inductively coupled plasma mass spectrometry (ICP-MS) 6,[11][12][13] and thermal ionisation mass spectrometry (TIMS). 1,9,10,[15][16][17] Fig. 5 illustrates that previous studies that have analysed less than 50 fg Pu have a reproducibility of around 10-20% 2s.…”

“…TIMS analyses can provide reproducibilities of better than 2%, but require greater than 200 fg Pu to achieve this. 9,10 Sector field MC-ICP-MS as utilised in this study produces ion collection efficiencies between 0.1% and 1% (where the efficiency equals ions counted in the analysis relative to atoms consumed by analysis). The highest efficiency is achieved by use of the multiple ion counting permitting the detection of 2 or more isotopes simultaneously.…”

Isotope ratio analysis of actinides, fission products, and geolocators by high-efficiency multi-collector thermal ionization mass spectrometry

“…Thermal ionization mass spectrometry (TIMS) [72,[108][109][110][111][112], inductively coupled plasma mass spectrometry [113][114][115][116][117][118][119][120], secondary ion mass spectrometry (predominately for particle or surface analysis) [71,54], accelerator mass spectrometry (predominately for high abundance sensitivity analysis) [10,[121][122][123][124], and resonance ionization mass spectrometry (high elemental selectivity) [19,[125][126][127][128] are frequently utilized for analysis of actinides and other radionuclides. Glow discharge mass spectrometry has been used for isotope ratio analysis of actinides, such as uranium [129][130][131], as well as fission-track TIMS for particles [132].…”

“…Highest precisions in isotope ratio analysis are traditionally reported using MC-TIMS instruments, with relative standard deviations as low as 0.01% or better [107,186]. Various methods have been developed to enhance the total/ionization efficiency (and thus the detection limit and precision) of TIMS, e.g., using carbon additives, benzene gas, and resin bead loads [110,[145][146][147]178], or platinum coating and electrodeposition [148]. These methods aim to reduce the formation of oxides, improve beam focus and ion transmission by reducing the spatial extent of the sample load, or enhance the work function of the ionizer materials (usually rhenium, tantalum, tungsten or platinum).…”

Plutonium isotope ratio analysis at femtogram to nanogram levels by multicollector ICP-MS

“…Until recently thermal ionisation mass spectrometry (TIMS) has been the primary method for the determination of plutonium isotope ratios. TIMS analysis of Pu has been achieved by ionisation from carburised filaments, 5,6 platinum over-plating 7 or by loading on ion-exchange beads. 8,9 With relatively large sample loads (w1 ng Pu), TIMS is capable of a reproducibility of better than 0.1% (2s) 7,10 At 200-500 fg the reproducibility is about 1.5% (2s), 5,11 and about 10% at v50 fg.…”