Siberian physicists have created and launched the first in Russia accelerator mass spectrometer allows precise dating archaeological and geological formations, to study the composition of the atmosphere and the tissue of living organisms from different historical periods, zavlaboratoriey told the Institute of Nuclear Physics of the Budker (INP), Russian Academy of Sciences Vasily Parkhomchuk.
"With the help of the accelerator mass spectrometer installed in the center of collective use of SB RAS" Geochronology of the Cenozoic, "produce ultra-sensitive analysis of the isotopic composition of carbon, which makes it possible to date the age of ancient objects found within a few hundred years", — Parkhomchuk said.
Accelerator mass spectrometry (IMR) — a modern super-sensitive method for isotope analysis, in which a careful selection is made of atoms of matter with the counting of isotopes. In the accelerator mass spectrometry charged particles dispersed to very high energies. Energy to which the ions are accelerated in the Siberian accelerator mass spectrometer, reaches 1 million electron volts or 1 MeV. This allows you to get a spectrum with very small impurities of unwanted molecular ions. By sensitivity analysis method is superior to any other in the thousands. The main use of UMS — radiocarbon dating of images and biomedical research using ultra-low amount of radiocarbon labels.
In particular, this method is widely used by archaeologists, paleontologists and geologists. Due to the high sensitivity of accelerator mass spectrometers, for dating only two or three milligrams of graphite — the finished sample obtained by burning the original sample. The minimum amount of material for analysis at UMC allows to date with it, even the most valuable historical artifacts. So, for dating in three UMS-laboratories in the U.S. and Europe, the famous Shroud of Turin, which, according to legend, it was at the burial wrapped the body of Jesus Christ, only took 150 milligrams of tissue. As a result of its expected age of about two thousand years, has not been confirmed — it turned out that the fabric was made about 700 years ago.
The Executive Director of the Center for collective use "Geochronology of the Cenozoic," said archaeologist Basil Zenin agency that can be dated by the radiocarbon method finds age no more than 40-50 thousand years to within a few hundred years. The average cost of such an analysis in the world is 500 to 1 thousand dollars, so the most important — is to master the technology of preparation of the sample to allow for accurate dating had two or three tests. According Zenina, the measurement error on the first Russian accelerator mass spectrometer was able to bring up to 0.4%, and this is not the limit. In this age of the samples dated foreign teams of scientists, and measurements made at UMC Russian Academy of Sciences, on average, the same.
According Parkhomchuk for initial calibration and validation UMC level of measurement accuracy INP used wood of large pine trees, drank fine "columns" from the center of the barrel to the cortex. "Ruler" with the annual rings of pine trees has become a convenient tool for data comparison, as dendrochronology method used at the Institute of Archaeology and Ethnography of the Russian Academy of Sciences, to determine to which year does each ring of the tree.
"During calibration, we were able to measure up to a year, as the radioactivity of the atmosphere has changed in the 1970s (after the testing of nuclear weapons in the USSR and the USA). Schedule content in the wood carbon-14 showed an average of twice the radioactivity of the atmosphere at this time", — Parkhomchuk said.
He noted that one of the first to test samples for radiocarbon dating method has become a bone of bison, found by chance by physicists under the building INP in the 1990s during the construction of an underground tunnel for one of the colliders Institute. Accelerator mass spectrometer determined the age of discovery — about 27,000 years.
The scientist explained that today the Siberian UMC for geologists date the oil samples and sediments, peat, for archaeologists — bone fragments, pottery and wood.
"In the world there are only a dozen of the most famous UMC laboratories of several hundred. These almost aerospace, where sterility is committed to the" vacuum "and we want results dating to the UMS of the same sample in Arizona, Oxford and on our equipment is fully matched and had the same value for researchers. Comparing our current results show that it is absolutely real in the near future ", — Zenin said.