Thu. May 1, 2014 9:00 AM - 10:45 AM 311 (3F)

Convener:*Toshio Nakamura(Center for Chronological Research, Nagoya University), Hiroyuki Matsuzaki(School of Engineering, The University of Tokyo), Kimikazu Sasa(Research Facility Center for Science and Technology, University of Tsukuba), Hisao Nagai(Faculty of humanities and Sciences, Nihon University), Masayo Minami(Center for Chronological Resarch, Nagoya University), Chair:Kimikazu Sasa(Faculty of Pure and Applied Sciences, University of Tsukuba)

Accelerator mass spectrometry (AMS) is a technique developed in 1977, to detect and count the small amount of nuclides in the environment, and to measure precisely the isotope ratios of the nuclides. In particular, by means of measuring rare radioisotopes in the environment, AMS techniques are applied for age measurement of samples from various application fields, such as geology, archeology and cultural properties. AMS can measure isotope ratios in the order of as low as 1.0E-10 to 1.0E-16, by the process of producing negative ions of specific nuclides by an ion source, accelerating the ions by a tandem accelerator, analyzing mass of the isotope ions by an analyzing magnet, and identifying the specific nuclides by an ionization detector. Thus AMS is used to measure isotope ratios of natural radionuclides of quite low natural abundances. AMS can be applied for studies of materials recycling and environmental science by using rare isotopes as a chemical tracer, and investigations of time sequence of tephra layers, land deposits, lacustrine and ocean sediments that are quite important for Quaternary research. This session offers a brief outlook of present status on technical progresses going on present days and interesting application programs, given by specific researchers and students engaged in AMS studies.