Abundance sensitivity is a measure of the tailing of an intense ion beam onto neighboring masses. This can be caused by the scattering of ions, for example by their interaction with residual gas molecules. The result are elevated baselines for masses neighboring bright ion beams.
The Retarding Potential Quadrupole (RPQ) acts as a high selectivity energy filter for ions with disturbed energy or angle. Both Thermo Scientific Neoma MC-ICP-MS and Thermo Scientific Triton XT TIMS can be configured with two RPQ lenses, producing abundance sensitivities of <0.5 ppm and < 20 ppb respectively (at 1 amu either side of 238U).
The ideal tool for nuclear safeguarding
Reliable analysis of 234U/238U and 236U/238U provides key information for nuclear safeguarding, but measurement can be difficult due to the very low abundance of 234U and 236U. Ion counters offer the lowest quantification limits for these isotopes. Scattered ions from 238U and 235U, can bias the measured ratios. The configuration of 2 RPQ lenses allows simultaneous measurement of 234U and 236U.