Accuracy in carbon 14 dating
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.An accelerator mass spectrometer, although a powerful tool, is also a costly one.Establishing and maintaining an accelerator mass spectrometer costs millions of dollars.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.
These negatively ionized carbon atoms pass through focusing devices and an injection magnet before reaching the tandem accelerator where they are accelerated to the positive terminal by a voltage difference of two million volts.
There are two accelerator systems commonly used for radiocarbon dating through accelerator mass spectrometry.
One is the cyclotron, and the other is a tandem electrostatic accelerator.
At this stage, molecules that may be present are eliminated because they cannot exist in this triple charged state.
The carbon atoms with triple positive charge further accelerate away from the positive terminal and pass through another set of focusing devices where mass analysis occurs.