At this stage, other negatively charged atoms are unstable and cannot reach the detector.
The negatively charged carbon atoms, however, move on to the stripper (a gas or a metal foil) where they lose the electrons and emerge as the triple, positively charged carbon atoms.
These two radiocarbon dating methods use modern standards such as oxalic acid and other reference materials.
Although both radiocarbon dating methods produce high-quality results, they are fundamentally different in principle.
Burning the samples to convert them into graphite, however, also introduces other elements into the sample like nitrogen 14.
When the samples have finally been converted into few milligrams of graphite, they are pressed on to a metal disc.
Thanks to nuclear physics, mass spectrometers have been fine-tuned to separate a rare isotope from an abundant neighboring mass, and accelerator mass spectrometry was born.
A method has finally been developed to detect carbon 14 in a given sample and ignore the more abundant isotopes that swamp the carbon 14 signal.
At the end of an AMS run, data gathered is not only the number of carbon 14 atoms in the sample but also the quantity of carbon 12 and carbon 13.
Radiometric dating methods detect beta particles from the decay of carbon 14 atoms while accelerator mass spectrometers count the number of carbon 14 atoms present in the sample.