Carbon dating used forensics
In addition, CAMS offers research opportunities for graduate students and postdoctoral fellows.According to Bench, in the past 15 years, the center has generated data for more than 300 graduate-level theses and annually supports the work required for 20 Ph Ds—a number that even a first-flight academic department would envy.“We also continue to support the Laboratory’s programs.For instance, we have become a leader in biological AMS research, and we have generated isotopes to calibrate sample recovery instruments for the National Ignition Facility.” (See , December 2012, A New Detector for Analyzing NIF Experiments; September 2011, A Beamline to National Security).Some of these scientists launch long-term careers at the Laboratory, such as geochemist Tom Guilderson.In 2011, Guilderson won the Department of Energy’s E. Lawrence Award for groundbreaking radiocarbon measurements of corals, helping researchers to better understand the ocean’s paleohistory and how oceanic processes affect the global carbon cycle.“It’s amazing to see the variety of problems brought in for analysis,” says CAMS director Graham Bench.By measuring the carbon-14 isotopes in various samples, CAMS researchers have helped solve cold cases and plumb the mysteries of the human brain and eye (this highlight), tested the efficacy of cancer drugs (See , September/October 2008, Developing New Drugs and Personalized Medical Treatment), and established the age of a potential Mayan codex. “We have strong ties to research communities worldwide in academia, private industry, and government agencies,” says Bench.
The precise measurement capabilities at CAMS allow researchers to identify the isotopic composition of a given sample.
In 1985, the University of California Regents joined Lawrence Livermore and Sandia national laboratories as equal partners to fund the Multi-User Tandem Laboratory, with Livermore physicist Jay Davis as the facility’s first director.
The Multi-User Tandem Laboratory initially focused on using accelerator mass spectrometry (AMS) to diagnose fission products of atomic tests and to conduct research in materials science, nuclear astrophysics, nuclear spectrometry, and neutron physics.
To extract carbon for measurement, researchers at CAMS turn a sample into carbon dioxide through either combustion or a chemical process and then reduce the carbon dioxide to graphite—a form of carbon—on an iron catalyst.
“The graphite is what we measure,” says Livermore scientist Bruce Buchholz, who helped pioneer this technique at CAMS.