Development and Application of Ultrasensitive Accelerator Mass Spectrometry

Since its inception in the late 1970s, Accelerator Mass Spectrometry (AMS) has become a powerful tool for the measurement of trace amounts of natural radionuclides. It differs from other forms of mass spectrometry try in that it accelerates ions to extraordinarily high kinetic energies before mass analysis, suppresses molecular isobars completely, and high-charge states for determination of very small isotopic ratios (10^-16). The technique takes advantage of the high ion energies achieved and negative ion interferential instabilities to enable extremely low backgrounds to be achieved. Therefore, they are extremely selective techniques for many applications and can be characterized by measuring the radionuclides concentrations, ¹⁰Be, ¹⁴C, ²⁶Al and ¹²⁹I for example, using AMS. In geology, through the measurement of ²⁶Al, ¹⁰Be and other nuclides, exposure age and erosion rate of earth surface can be determined, and geomorphic evolution can be studied. In marine science, through the measurement of ¹²⁹I, ¹⁰Be and other nuclides, deposition rate and growth rate of marine sediments, manganese nodules, manganese crusts can be determined. In archeology, through the measurement of ¹⁴C, ¹⁰Be and other nuclides, precious samples dating and chronological study on the Quaternary human evolution can be achieved. In environmental science, through the measurement of ¹²⁹I, ¹⁴C and other nuclides, Nuclear pollution, urban environmental pollution and global climate change etc, can be monitored and studied. In this paper, the basic measurement principle, equipment and technological developments of Accelerator Mass Spectrometry were described, and its applications in geology, oceanography, archaeology, environmental science and other relative fields were presented.