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High Precision Isotope Ratio Measurements using a ICP-Hexapole Magnetic Sector Instrument. Z. Palacz, P. Turner, S. Meffan-Main. Sampling cone (sampler). Flight tube LOS valve. Acceleration Lenses. Shock wave. Argon plasma. Skimmer cone. To magnetic mass spectrometer. ICP torch.
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High Precision Isotope Ratio Measurements using a ICP-Hexapole Magnetic Sector Instrument Z. Palacz, P. Turner, S. Meffan-Main.
Sampling cone (sampler) Flight tube LOS valve Acceleration Lenses Shock wave Argon plasma Skimmer cone To magnetic mass spectrometer ICP torch Hexapole collision cell Zone of silence Expansion Volume Pump Intermediate Pump Collision Chamber Pump Acceleration Chamber Pump Hexapole
Effect of Argon in hexapole on U intensity. 9 8 7 6 5 238U Intensity (volts) 4 3 2 optimal 1 0 0 0.5 1 1.5 2 Ar gas flow ml/min
U Sr Mg Flat Top Peak shapes across the Mass Range
11 10 In Pb 10 10 Nd U Rh Hf Cs cps/ppm Tb Th Sr Os Co Mg 3-4 eV 9 10 5-6 eV Ionization Potential 6-7 eV Fe 7-8 eV Li 8-9 eV 8 10 200 0 50 100 150 250 Mass Sensitivity of the IsoProbe
40Ca,52Cr,54Fe,56Fe Show no Evidence of Argon Interferences.
Stability of Mass Bias Over 1hr 0.745 0.7449 146Nd/144Nd 0.7448 Mean 0.744872+/-25 1SD Mass Bias is 1.59% per amu 0.7447 0 10 20 30 40 50 60 70 MINUTES
Reproducibility of 143Nd/144Nd in La Jolla 0.51188 0.51187 143Nd/144Nd 0.51186 0.511864+/-10ppm 1SD 150ppb La Jolla CETAC MCN 6000 Each point 6minutes using 30ng Nd 144Nd intensity 2e8 cps ~6e9cps/ppm 0.51185 TIMS 0.511858 0.51184 0 2 4 6 8 10 12 Measurement
0.28218 AMES JMC 475 0.2821629+/-44 1SD 0.28217 0.28216 176Hf/177Hf 0.28215 0.2821495+/-35 1SD 0.28214 0 2 4 6 8 10 12 14 Analysis 176Hf/177Hf in Ames and JMC standards. 15ng per analysis.
Hexapole collision cell reduces energy spread to <1ev. Hexapole is stable and produces a stable mass bias which is largely independent of gas pressure. Hexapole removes argides Hexapole produces an increase in sensitivity. ~0.5% ion:atom efficiency for Hafnium. IsoProbe can produce reproducibility's for Nd of ~10ppm. Conclusions