Keywords:Accelerator Mass Spectrometry (AMS), Femto-level isotope analysis, 6 MV tandem accelerator
The 6 MV Accelerator mass spectrometry (AMS) system for multi-nuclide measurements has been successfully established and operated at the University of Tsukuba since 2016. Long-lived radionuclides of 10Be, 14C (graphite and CO2), 26Al, 36Cl, 41Ca and 129I have been detected with a five-anode dE - E gas ionization detector in the range of ultra-low isotope ratios from 10-10 to 10-15. The AMS performance is entirely satisfactory to measure cosmogenic and anthropogenic nuclides for applications in the earth environmental research field by means of the 6 MV AMS system. Especially, a background of 41Ca AMS is reached to 41Ca/Ca ~ 3 × 10-15 as the result of improved isobaric separation techniques. In addition, 90Sr-AMS is currently under development. In this presentation, I will report the most advanced AMS facility and detection techniques for femto-level isotope analysis.