Latest Developments in Radiocarbon Dating

Question

What are the latest developments in carbon dating technology?

Answer

The theory and methods of Carbon-14 (C14) dating were developed through the pioneering work of Willard Libby and his team of scientists during the late 1940’s. That early work established the presence of C14 in organic samples, the rate of its radioactive decay (half-life) and that it could be used as a reliable absolute method of dating organic materials.

Since that time the basic principles of radiocarbon dating have remained the same and the major developments in the technology have involved the adoption of different techniques. The original solid carbon method developed by Libby was then quickly replaced by the Gas proportional counting (GPC) method, which enabled background radiation to be more easily identified and excluded and this technique was then supplemented by Liquid scintillation counting (LSC) during the 1960’s.

The most recent technique developed to detect Carbon-14 is Accelerator Mass Spectrometry (AMS) which was developed in the late 1970’s. This method differs from the other techniques because it directly counts the number of C14 atoms (relative to those of C12) rather than by counting the beta-particles of decay. This makes AMS a more efficient way to measure C14 content and means that smaller samples can be dated.

References

Libby, W. F., (1955) Radiocarbon Dating, 2nd ed., Chicago: University of Chicago Press.

Theodorsson, P., (1991) Gas Proportional versus Liquid Scintillation Counting, Radiometric versus AMS Dating, Radiocarbon, 33 (1), 9-13.

Bayliss, A., McCormac, G., and van der Plicht, H., (2004) An illustrated guide to measuring radiocarbon from archaeological samples, Physics Education, 39 (2), 137-144.