The PIMS project status
Prof. Stewart Freeman1, Richard Shanks1, Cameron McIntyre1, Tom Donoclift1, Mark Sundquist2, Kenny Kearney2, Allan O’Connor2, Richard Kitchen2, Mike Mores2, Thilo Hauser2, Matthieu Cavellier3, Arun Annaluru3, Vincent Bertrand3, Doug Hamilton4, Issaku Kohl4, Taylor Graham4
1Scottish Universities Environmental Research Centre, , United Kingdom, 2National Electrostatics Corp., , USA, 3Pantechnik S.A., , France, 4Thermo Fisher Scientific, ,
The academic and commercial project to develop and exploit positive ion mass spectrometry (PIMS) analysis of long-lived radionuclides continues. Further instruments are being constructed following the establishment of radiocarbon measurement on a prototype that is competitive with established techniques. Design revisions include the removal of ion analysis between the plasma ion source and the chemical reaction cell that both removes molecular interferences to ¹⁴C detection and by negatively ionising the transmitted particle beam also permits the subsequent elimination of the interfering atomic isobar. Essentially the gas cell is now also used to control the space charge of the multi-milliamp ion source output in addition to filtering the beam. Tests on the prototype instrument show that this does not raise measurement background, but the cell thermal loading needs management. Moreover, new hardware has been built to maintain the optimum flow of analyte gas into the plasma source and to make the PIMS instrumentation compatible with usual radiocarbon analysis laboratories’ workflow; sealed glass ampoules of cryogenically focussed CO₂ samples may now be automatically processed, and without the performance compromise of alternative mass spectrometry. Finally, Thermo Fisher Scientific company has newly joined the project. Suites of their technologies that are complimentary to PIMS, including multi-element stable isotope mass spectrometry and coupled handling of organic and inorganic materials are being integrated. The vision is of an automated laboratory technology package combining the disparate usual analyses for best performance, high productivity and cost savings.
Physicist Stewart P.H.T. Freeman is University of Glasgow Professorial Research Fellow. He develops and applies ultrasensitive long-lived radionuclide detection technology. After gaining a doctorate from the University of Oxford he focused on life-science applications at the Lawrence Livermore National Laboratory and Stanford University in California before joining the Scottish Universities Environmental Research Centre in 2000. There he leads the Accelerator Mass Spectrometry Laboratory and has pursued positive-ion techniques as an alternative to established accelerator microanalysis. Subsequently he also joined the Board of Directors of National Electrostatics Corp. to exploit his co-invention of PIMS.