Reference materials are also pressed on metal discs.These metal discs are then mounted on a target wheel so they can be analyzed in sequence.Carbon-14 is continually formed in nature by the interaction of neutrons with nitrogen-14 in the Earth’s atmosphere; the neutrons required for this reaction are produced by cosmic rays interacting with the atmosphere.
From these data, concentration ratio of the isotopes can be known to allow evaluation of the level of fractionation.
The greatest advantage that AMS radiocarbon dating has over radiometric methods is small sample size.
The carbon-14 method was developed by the American physicist Willard F. It has proved to be a versatile technique of dating fossils and archaeological specimens from 500 to 50,000 years old.
The method is widely used by Pleistocene geologists, anthropologists, archaeologists, and investigators in related fields.
In mass analysis, a magnetic field is applied to these moving charged particles, which causes the particles to deflect from the path they are traveling.
If the charged particles have the same velocity but different masses, as in the case of the carbon isotopes, the heavier particles are deflected least.
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.
Radiocarbon decays slowly in a living organism, and the amount lost is continually replenished as long as the organism takes in air or food.