These instruments combine the ionisation efficiency of an inductively coupled plasma (ICP) source, capable of ionising most elements, with the high precision and accuracy in isotope measurement offered by a magnetic sector analyser. As a result many elements that could not be measured because of a high ionisation potential (such as Hf or W) or limitations imposed by instrumental fractionation (stable isotopes of the transition elements) can now be routinely measured to a high precision. When taken with the facility of the plasma source for coupling with laser based sampling techniques these instruments have now been applied with spectacular success to geological and environmental materials. The plasma source mass spectrometer in the Isotope Geochemistry Group was designed in collaboration with the manufacturer Nu Instruments and the Departments of Earth Sciences at the Open University and Oxford University. Every aspect of the instrument has been considered in a totally new design. The result has been the production of an instrument that is highly reliable, providing precise and accurate isotope ratio determination. A double focusing magnetic sector analyser is used to focus the energy spread of the plasma beam, incorporating variable dispersion ion optics to focus the beams into a fixed multi-collector array, that has no moving parts. This instrument was installed four years ago and has already been successfully used for the measurement of Pb and transition metal isotopes and pioneering measurements of extremely small Th samples in river waters.
Lead Academic - Dr Ian Parkinson
Telephone: +44 (0) 1908 659780
Laboratory Manager - Dr Manuela Fehr
Telephone: +44 (0) 1908 332438