How do you use carbon fourteen to measure the age?
One is obvious a small amount of sample, only 1 ~ 5 mg samples can be, such as a piece of fabric, bone chips, toner trace of ancient ceramics in the surface or pores can be measured; while the conventional carbon - 14 dating rules 1 to 5 grams of samples differ by 3 orders of magnitude. The two is high sensitivity. The sensitivity of 10-15 to 10-16 isotope ratio measurement; while the conventional carbon - 14 dating rules with a difference of 5 to 7 orders of magnitude. Three is a short measurement time, measurement of modern carbon to reach 1% accuracy, only 10 to 20 minutes; while the conventional carbon - 14 dating is 12 ~ 20 hours. It is due to carbon - 14 accelerator mass spectrometry dating method has the advantage, since its inception, has been paid attention to by archaeologists, paleontologists and geologists, and is widely used. It can be said that within 50000 years of cultural relics on the determination of samples, carbon - 14 accelerator mass spectrometry dating method is determined the accuracy of a maximum of 1. carbon. 14 is a radioactive isotope of carbon, was found in 1940. It is produced by cosmic rays collide with a nitrogen atom in the air, which has a half-life of about 5730 years, as the decay of beta decay, 14 atoms into carbon nitrogen atoms.
Then, carbon - 14 dating method is to determine the remains of ancient age? Originally, cosmic rays can produce radioactive carbon -- 14 in the atmosphere, and can enter all living tissue carbon dioxide and oxygen - synthesis combined, first for the absorption of plants, after the animal into a plant or animal. As long as they live. Continuous absorption of carbon - 14, to maintain a certain level in the body. When the organism dies, which will stop breathing carbon - 14, within their organization, with a half-life of 14 carbon began 5730 years of decay and gradually disappear. For any carbon containing material, as long as the determination of the remaining 14 of the content of radioactive carbon you can, that the age of 14. Carbon dating method is divided into conventional carbon - 14 dating method and carbon - 14 accelerator mass spectrometry dating two. At that time, since it is invented by Libby conventional carbon - 14 dating method, this 1950. The technology and application of methods have significant progress in the world, but its limitations are obvious, namely the time measurement must use a large number of samples and longer. Thus, carbon - 14 dating accelerator mass spectrometry technology developed. Carbon - 14 accelerator mass spectrometry dating method has unique advantages.
