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Measurement of 234U/238U in IRMM184 uranium standard using the Isotopx ATONA and Zeptona Faraday detector systems
Zenon Palacz, Shaun Yardley, Matt Hockley, Steve Guilfoyle Introduction High precision determination of 234U / 238U is important in many geological research applications. The typically low abundance of 234U (234U / 238U = 0.000053196 in IRMM184) in these applications has necessitated the use of ion counters for this isotope, while the much larger 238U must…
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Optimising ATONA integration times for beam intensity
Application note AN22_01 Matt Hockley, Isotopx Ltd, Dalton House, Dalton Way, Middlewich, Cheshire, CW10 0HU, UK. How do I select an integration time to optimise my measurement precision? Introduction When measuring an ion beam, there are two sources of uncertainty on the measurement: uncertainty due to amplifier noise, and uncertainty due to the shot noise…
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Measurement of clumped CO2 isotopologues using
SIRIX stable isotope ratio mass spectrometerApplication note AN22_02 Isotopx Ltd, Dalton House, Dalton Way, Middlewich, Cheshire, CW10 0HU, UK. How can SIRIX be used to improve CO2 measurement? Introduction The objective of CO2 isotopologue studies is to accurately and precisely measure small differences (Δ 47) in the abundance of m/z 47 (13C18O16O) relative to m/z 44 12C16O16O. Small changes in…
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Isotopic analysis of sub-nanogram Nd standards using new ATONA amplifiers
Andrew A. Reinhard 1, Jeremy D. Inglis1, Robert E. Steiner1, Stephen LaMont1, Matthew G. Jackson2 1Nuclear and Radiochemistry, Los Alamos National Laboratory 2Department of Earth Science, University of California Santa Barbara Motivation In the last several years new amplifier technologies have been released for thermal ionization mass spectrometers (TIMS) including the ATONA amplifiers produced by…
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U-Pb TIMS Geochronology using ATONA® Amplifiers
Dawid Szymanowski & Blair Schoene Department of Geosciences, Princeton University; dszymanowski@princeton.edu; bschoene@princeton.edu V11D-0124 Key Points ATONA [aA (10-18 A) to nA (10-9 A)] is a new Faraday cup signal amplifying technology for Isotopx Phoenix thermal ionisation mass spectrometers (TIMS) Main advantages for TIMS U–Pb geochronology (compared to conventional ion counting with peak-hopping): Better precision and…
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Total evaporation analysis (TE) of 500ng loads of U500 using Phoenix TIMS – Precision and Efficiency.
Introduction Uranium does not have a stable isotope pair that can be used to correct for mass fractionation in a TIMS. Measurements have to be made using external mass fractionation control or by total evaporation of the sample and simultaneous (static) collection of all isotopes. Addition of a doubly enriched isotope spike e.g. 233U and…
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Isotope Ratio Analysis of NBS U010 Uranium Standard Using External NBS U500 Mass Fractionation Correction
Introduction The NBS Uranium Standard U010 has been analysed in the STATIC Faraday multi-collection mode. This standard has a large range in isotope abundance and the accuracy and precision of an analysis are a good test of the linearity and noise levels of the Faraday cups. Because Uranium does not have a stable isotope ratio,…
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Neodymium isotope ratio analysis using the Phoenix TIMS
Introduction Neodymium together with strontium isotope ratio measurements are the benchmark analyses that define the ultimate precision and accuracy of isotope ratio measurements that Thermal Ionization mass spectrometers are capable of. The mass fractionation which occurs during thermal ionization can be compensated for using the exponential mass fractionation law. This can lead to single analysis…
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2ppm reproducibility of 87Sr/86Sr achieved using the Phoenix TIMS
Introduction Very high precision Strontium isotope ratio measurements are particularly important in some geochronological applications. For example, variations as small as 0.00001 in 87Sr/86Sr are significant in high resolution dating of marine carbonates. (e.g. McArthur JM, Howarth RJ, Bailey TR. 2001.). In order to test the capabilities of the Phoenix Thermal Ionisation Mass Spectrometer to…
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87Sr/86Sr analysis of < 10ng NBS 987 on Phoenix TIMS
Introduction High sensitivity Sr isotope ratio measurements using TIMS can be used to evaluate sub millimetre isotope variations in zoned minerals and fluid inclusions. Sample sizes of a few nanograms of Sr are generated and so “every ion counts” to get a precise measurement. In this preliminary study a Phoenix TIMS was used to analyse…
