Uses of mass spectrometry in carbon dating really fun dating games
At the terminal they pass through either a very thin carbon film or a tube filled with gas at low pressure (the stripper), depending on the particular accelerator.
-counting method) or by directly counting the radiocarbon atoms using a method called Accelerator Mass Spectrometry (AMS).
Measurement of the radioactivity of the sample works very well if the sample is large, but in 9 months less than 0.01% of the radiocarbon ions will decay, so in a reasonable measurement time (typically a few weeks) only a very small proportion of the radiocarbon atoms are detected by this method.
AMS, on the other hand, can in principle detect a much higher proportion (typically about 1% of the total) allowing sample sizes to be smaller by a factor of about a thousand.
These two pieces of information are sufficient to completely identify the ion as C atoms at the rate at which they decay.
This requires sufficient atoms to be present to provide a large enough decay rate, as described above.