Speaker
Description
Barium tagging (“Ba-tagging”) has the potential to become a defining technology for next-generation liquid and gas xenon time projection chambers searching for neutrinoless double-beta decay ($0\nu\beta\beta$) in $^{136}$Xe. The successful identification of the $\beta\beta$-decay daughter $^{136}$Ba at the reconstructed decay site would provide an event-by-event confirmation of the parent decay isotope $^{136}$Xe and enable unprecedented background rejection. This capability could allow experiments such as nEXO to operate in a near background-free regime at the multi-tonne scale.
We review ongoing efforts in barium ion localization, extraction, isolation and trapping strategies aimed at single-ion identification. We present the current status, highlighting the recent progress made by the Ba-tagging research and development program for nEXO. Finally, we outline the near-term milestones and the pathway toward demonstrating a complete Ba-tagging system to benchmark the maximum deliverable tagging-efficiency.
