T04_P05

Facility Report: NOSAMS operations and the new MICADAS

Broek T¹, Roberts M¹, Longworth B¹, Burton J¹, Crossen A¹, Cruz A¹, Elder K¹, Gagnon A¹, Gospodinova K¹, Handwork S¹, Hansman R¹, Kurz M¹, Lardie Gaylord M¹, Trowbridge N¹, Xu L¹, Lang S¹

¹National Ocean Sciences Accelerator Mass Spectrometry Facility, Woods Hole, United States

The National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility at Woods Hole Oceanographic Institution provides ¹⁴C-AMS analyses and expertise in support of the US oceanographic and earth science communities. NOSAMS measures on average 7,300 unknowns per year on two unique AMS instruments. The CFAMS system, commissioned in 2006, is based around a 500 kV NEC Pelletron tandem accelerator and a modified 134 position NEC MC-SNICS ion source and currently serves as the primary instrument for client samples. In late 2021, the original NOSAMS 3 MV USAMS Tandetron instrument, in operation since 1992, was decommissioned and replaced in 2022 with an IonPlus 200 kV MICADAS with gas interface and associated sample introduction peripherals (elemental analyzer and carbonate handling system). Here, we provide an update on the NOSAMS facility AMS systems and present results from the initial implementation and operation of the MICADAS, including quantification of system accuracy and precision with both solid and gaseous samples, comparison of data from materials measured as both graphite and CO₂ gas, performance of small (<100 µg C) solid samples, and modifications to solid sample targets. We also discuss integration of the new system into our laboratory workflows, data reduction software, and database system.