More accurate methods were developed using gas-proportional counters and liquid-scintillation counters.
However, when the organism dies, the amount of c14 declines such that the longer the time since death the lower the levels of c14 in organic tissue.
Research Scientist at the NSF Arizona AMS Facility and Department of Geosciences at the University of Arizona, in Tucson, Ariz. Its primary use is for radiocarbon dating of small samples of carbon, although many measurements have also been made on the longer-lived radionuclides such as I, which have applications to geology and marine studies.
This article is reproduced from Nuclear News, June 19998, and is based on a paper presented at the ANS Winter Meeting, held November 16-20, 1997, in Albuquerquete N. AMS has become an accurate and precise method for dating many types of materials - including such interesting items as the Shroud of Turin and the Dead Sea Scrolls, which will be discussed laterwhere only a small sample can be spared.
Wenn die kosmische Strahlung auf Atome der Atmosphäre trifft, werden durch Spallation Neutronen freigesetzt.
Wenn das in der Atmosphäre mit Abstand häufigste Isotop, das Stickstoff-Isotop Innerhalb dieser Zeit verteilt sich der Radiokohlenstoff weiträumig, siehe Kohlenstoffkreislauf.