Development of Non-Radiocarbon Accelerator Mass Spectrometry at the University of Tsukuba

The 6 MV Pelletron tandem accelerator was designed and constructed for multi-nuclide AMS at the University of Tsukuba in 2016¹). It has two MC-SNICSs for the routine measurement. A five-electrode AE—-E gas ionization detector is installed on the end station of the rare-particle detection system. We have developed ultrasensitive detection techniques for ¹⁰Be, ¹⁴C (graphite and CO₂), ²⁶Al, ³⁶Cl, ⁴¹Ca, ⁹⁰Sr and ¹²⁹I in isotopic-ratio ranges of 10^-10 to 10^-15. In the case of ³⁶Cl AMS, we developed the sulfur removal method to reduce ³⁶S contamination. AgCl samples are pressed into an AgBr backing in a large Cu sample cathode (6 mm diameter) in order to reduce ³⁶S contamination"). ³⁶ClCl measurements are performed with a carbon foil (4.8 ug cm') and an 8+ charge state at 6.0 MV, with ³⁶Cl⁸⁺ being injected into the detector at 54.0 MeV.