Accelorator mass spectrometry for dating
Dr Christine Prior is Team Leader of the Rafter Radiocarbon Laboratory at GNS Science.
The amount of carbon dioxide in the atmosphere today is higher than that at any time in the last 420,000 years (figure 1).More research is necessary to explain past changes in COC produced by atmospheric weapons testing (between 19), as it dissolves in surface oceans and is taken up and respired by land plants can be traced.On longer timescales, the radioactive decay of C provides information on slower exchanges with the much larger stores of carbon in the deep ocean and the carbon stabilized in soils and sediments.An accelerator then increases the kinetic energy of the carbon ions to 10-30 million electron volts and moves them through a tube where a powerful electromagnet makes them change direction. Because carbon-14 decays over time, the amount of it in a sample indicates the age of the sample.How much their path bends depends on their mass: Lighter ions bend more. Penn State will soon be home to an accelerator mass spectrometer (AMS) that will allow researchers all over the country to do high-precision carbon dating to address questions about Earth's past and present.