In order to measure radiocarbon ages it is necessary to find the amount of radiocarbon in a sample. This measurement can be made either by measuring the radioactivity of the sample the conventional beta -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. The method is relatively new because it needs very complicated instruments first developed for Nuclear Physics research in the late 20th century.
There are two techniques in measuring radiocarbon in samples—through radiometric dating and by Accelerator Mass Spectrometry AMS. The two techniques are used primarily in determining carbon 14 content of archaeological artifacts and geological samples. 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. 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. Both carbon dating methods have advantages and disadvantages. Mass spectrometers detect atoms of specific elements according to their atomic weights.
Mass spectrometry MS is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are typically presented as a mass spectrum , a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is used in many different fields and is applied to pure samples as well as complex mixtures. A mass spectrum is a plot of the ion signal as a function of the mass-to-charge ratio.
However, estimates of impactor flux may be biased by the fact that most of the dated Apollo samples were only tenuously connected to an assumed geologic context. Given the great cost of sample return missions, combined with the need to sample multiple terrains on multiple planets, we have developed a prototype instrument that can be used for in situ dating to better constrain the age of planetary samples. Methods: We demonstrate the first use of laser ablation resonance ionization mass spectrometry for 87 Rb- 87 Sr isochron dating of geological specimens. The demands of accuracy and precision have required us to meet challenges including regulation of the ambient temperature, measurement of appropriate backgrounds, sufficient ablation laser intensity, avoidance of the defocusing effect of the plasma created by ablation pulses, and shielding of our detector from atoms and ions of other elements.