BRAMS is a new state-of-the-art radiocarbon dating facility at the University of Bristol.
The high artistic quality of the earliest paintings underlines the importance of absolute chronology in any attempt to study the evolution of prehistoric art.
This process, called sputtering, separates neutral, as well as positive and negative ions from the sample surface.
The sample is held at a negative potential, and negatively charged ions are accelerated away from the sample, resulting in a beam of negative ions (Figure 2, below). The low energy (~5-10 ke V) diverging beam that leaves the ion source is accelerated, focused and transported to the accelerator by the injector system. Most AMS systems use sequential injection, a process that switches between stable and rare isotopes via the application of varying voltages to the electrically insulated vacuum chamber of the analyzer magnet.
Step into the Center for Accelerator Mass Spectrometry at Lawrence Livermore National Laboratory on any given day, and you may see researchers tracking the dynamics of the Earth’s carbon cycle, searching for signatures of nuclear fuel reprocessing or determining the age of remains from the Chicago Police Department’s cold case files.
These vastly different projects have one thing in common: They all use accelerators to measure levels of carbon-14 and other isotopes.