ARTEMIS : a facility to count carbon-14 atoms.
When the remains to date are very old, the nuclei of carbon-14 become so rare that the observation of their decays becomes impractical. One has to count the carbon-14 atoms themselves. This is done in facilities designed for this purpose, made of a mass spectrograph associated with a small accelerator. Samples of a few milligrams of the vestige to date are introduced in the installation which allows to measure the isotopic ratios of the ordinary carbon and its radioactive isotope. The photograph shows the CEA ARTEMIS facility in Saclay (France).