Development of a Ba-tagging demonstration apparatus at TRIUMF

nEXO is a next generation experiment searching for neutrinoless double beta decay (0νββ) in the isotope ¹³⁶Xe. An observation of this decay would imply lepton number violation and require the neutrino to be its own antiparticle, i.e. beyond the Standard Model of particle physics.

To increase nEXO's sensitivity and to verify a potential signal as originating from true double beta decay (ββ) events in a future upgrade, the collaboration is developing a Ba-tagging technique with the aim of identifying the ¹³⁶Xe decay daughter ¹³⁶Ba. The decay volume is probed for the presence of Ba when a candidate 0νββ event is detected. Since ¹³⁶Ba is the daughter nucleus in ¹³⁶Xe double beta decay, such an approach offers an opportunity to reject backgrounds at near maximal levels.

The nEXO collaboration is investigating to extract and identify single barium ions using radioactive beams at TRIUMF. The group at TRIUMF is developing an apparatus that can demonstrate the full chain of the barium tagging technique from retrieval or detection. This presentation will discuss the radioactive ion beam approach and testing plan for Ba-tagging, focusing on the preparation of the Ba-tagging apparatus prior to first beam runs at the ISAC II facilities.