Speaker
Description
The 6 MV multi-nuclide AMS system at the University of Tsukuba has been in operation for 10 years since 2014 [1]. The injector has two cesium sputtering negative ion sources: the 40-sample MC-SNICS and the MCG-SNICS gas/solid hybrid ion source. The accelerator with the 6 MV Pelletron tandem (National Electrostatics Corp, 18SDH-2) has a gas stripper tube and a foil changer with 80 foil holders for the charge exchange reaction. Carbon stripper foils are used mainly for obtaining highly charged ions in $^{36}$Cl, $^{41}$Ca and $^{90}$Sr AMS. The rare-particle detection line has a 22.5° ESA for filtering energy-to-charge-state ratios (E/Z) with a resolution of E/dE = 200. A five-electrode dE-E gas-ionization detector is installed as the end station of the detection system. Highly sensitive detections of $^{10}$Be, $^{14}$C, $^{26}$Al, $^{36}$Cl, $^{41}$Ca, and $^{129}$I have been performed [2], with background levels of 10$^{-14}$ to 10$^{-15}$ for these isotope ratios. In addition, AMS analytical techniques for $^{90}$Sr, $^{135}$Cs, $^{210}$Pb, and other nuclides are being developed. Currently, $^{90}$Sr AMS is performed in isotopic ratio ranges of 10$^{-9}$ to 10$^{-13}$ with a total beam energy of 51.7 MeV [3]. The $^{90}$Sr/Sr AMS background is 6 × 10$^{-13}$ (~ 3 mBq $^{90}$Sr). The radioactive halogens for $^{36}$Cl and $^{129}$I have been the main research nuclides at the 6 MV multi-nuclide AMS system. In this presentation, we will report on the progress of AMS detection techniques and applications using multi-nuclides for anthropogenic and cosmogenic tracers in the environment.
References
[1] K. Sasa et al., Nucl. Instrum. Methods Phys. Res. B, 361 (2015) 124.
[2] K. Sasa et al., Nucl. Instrum. Methods Phys. Res. B, 437 (2018) 98.
[3] K. Sasa et al., J. Nucl. Sci. Technol., 58(1) (2021) 72.
| Student Submission | No |
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