Radioactive dating mass spectrometer
This requires a relatively large sample, depending on the amount of carbon remaining in that sample.
By the late 1970s a number of researchers discovered that when accelerating sample atoms in the form of ions to much higher energies in particle accelerators, a much smaller sample was required to derive confident dates—in most cases only milligrams instead of tens of grams for scintillation counting.
We can be 68.3 percent certain that the dates fall either from 4454 to 4416 BC or from 4408 to 4354 BC.
There are multiple possible dates because the radiocarbon date of 5568 BP intercepts the calibration curve at more than one point.
As soon as a plant or animal dies, they cease the metabolic function of carbon uptake; there is no replenishment of radioactive carbon, only decay.
Libby, Anderson, and Arnold (Taylor and Aitken ) is the name given to this value, which Libby measured at 5568±30 years. After 10 half-lives, there is a very small amount of radioactive carbon present in a sample.
The calibration method used and any further contextual information should also be supplied.
C ages of samples were calculated by decay counting in mainly scintillation counters.
The convention calls for reporting the provenience of the sample, the laboratory number, the radiocarbon age, and then the calibrated (in this case dendrocalibrated) age at one or two standard deviations (note that most of these dates yielded multiple intercepts).
The results obtained will be the basis of an optimized design for a radiocarbon dating instrument comparable in size, complexity and cost to standard mass spectrometers.
C atoms are required for an accurate AMS measurement, this represents a million-fold sensitivity enhancement compared to scintillation-counter detection.
At about 50,000 to 60,000 years, then, the limit of the technique is reached (beyond this time, other radiometric techniques must be used for dating, such as C concentration or residual radioactivity of a sample whose age is not known, it is possible to obtain the number of decay events per gram of carbon.
By comparing this with modern levels of activity (1890 wood corrected for decay to AD 1950) and using the measured half-life, it becomes possible to calculate a date for the death of the sample.