Hannover 2016 – scientific programme

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MS: Fachverband Massenspektrometrie

MS 9: Accelerator Mass Spectrometry and Applications II

MS 9.4: Talk

Thursday, March 3, 2016, 15:30–15:45, f128

Development of high-sensitivity AMS for ⁹³Zr — Boyana Deneva¹, Thomas Faestermann¹, Leticia Fimiani¹, José Manuel Gómez-Guzmán¹, Karin Hain¹, Gunther Korschinek¹, •Peter Ludwig¹, Victoria Sergeyeva², Nicolas Thiollay², and Olivier Vigneau² — ¹Physik Department TUM, Garching — ²Centre CEA, Cadarache, France

The radioisotope ⁹³Zr (T_1/2 = 1.5 Ma) represents a very challenging background situation for AMS. Its two stable neighbouring isotopes ⁹²Zr and ⁹⁴Zr only differ in mass by ∼1%, making them difficult to separate. Additionally, the stable isobar ⁹³Nb with only one unit difference in proton number, needs to be suppressed in order to achieve high sensitivity. In recent studies at the Maier-Leibnitz-Laboratory in Garching, different experimental approaches have been explored: Firstly, by using stacked passive absorber (SiN) foils, exploiting the energy loss difference of ⁹³Zr and ⁹³Nb, in combination with a time-of-flight measurement and isotopic suppression of the neighbouring isotopes by a Wien-filter. And secondly, using the gas-filled magnet system GAMS providing isobaric suppression, in combination with an ionization chamber with a five-fold segmented anode. Both techniques have shown excellent preliminary results with sensitivities for the atom ratio of ⁹³Zr/Zr≈ 2· 10⁻¹⁰. This opens the door towards applications in the fields of nuclear materials, fuel behaviour, and waste management, but also nuclear astrophysics, where ⁹³Zr represents a weak branching point in the s-process.