Accelerator mass spectrometry (AMS) is a technique for direct measurement of the concentration of radioisotopes.
A radiocarbon measurement can be obtained on a sample of ~0.5 mg of carbon, and measured to 40 years in uncalibrated radiocarbon age in a measurement time of 3040 minutes on each sample.
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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.If you're seeing this message, it means we're having trouble loading external resources on our website.If you're behind a web filter, please make sure that the domains *.and *.are unblocked.Ocean sediment C-14 data The Lamont-Doherty Earth Observatory of Columbia University has compiled 974 C-14 dates from 309 ocean sediments cores, covering the period from 40,000 years BP to the present worldwide. The USGS Bear Lake Project aims to create records of past climate change for the Bear Lake region,including changes in precipitation patterns during the last 10,000 years and how the size of Bear Lake has varied in the past, to assess the possibility of future flooding and drought.
Your access to the NCBI website at gov has been temporarily blocked due to a possible misuse/abuse situation involving your site.If you would like to set up information regarding a project in which radiocarbon dating illuminated or solved a problem or in which C14 played a central role, please contact [email protected] The Origins of Angkor Archaeological Project From the University of Otago (New Zealand) and the Fine Arts Department of Thailand, the project is concerned with investigating archaeology of pre-formative Angkorean society of South East Asia.Radiocarbon dating underpins the chronological aspects of the investigation.Organisms at the base of the food chain that photosynthesize – for example, plants and algae – use the carbon in Earth’s atmosphere.They have the same ratio of carbon-14 to carbon-12 as the atmosphere, and this same ratio is then carried up the food chain all the way to apex predators, like sharks.Atoms of the same element that have different numbers of neutrons are called isotopes. Most carbon on Earth exists as the very stable isotope carbon-12, with a very small amount as carbon-13.