An apparatus to manipulate and identify individual Ba ions from bulk liquid Xe

TL;DR

This paper presents a system for transporting and identifying barium ions in liquid xenon, aiding in the detection of neutrinoless double beta decay by confirming the decay event through barium ion identification.

Contribution

It introduces a novel apparatus combining laser-induced desorption and resonance ionization spectroscopy for single-ion detection in liquid xenon environments.

Findings

Successful collection of Ba ions in liquid xenon

Effective identification of Ba ions via RIS and TOF mass spectrometry

Potential application in neutrinoless double beta decay experiments

Abstract

We describe a system to transport and identify barium ions produced in liquid xenon, as part of R&D towards the second phase of a double beta decay experiment, nEXO. The goal is to identify the Ba ion resulting from an extremely rare nuclear decay of the isotope $^{136}$Xe, hence providing a confirmation of the occurrence of the decay. This is achieved through Resonance Ionization Spectroscopy (RIS). In the test setup described here, Ba ions can be produced in liquid xenon or vacuum and collected on a clean substrate. This substrate is then removed to an analysis chamber under vacuum, where laser-induced thermal desorption and RIS are used with time-of-flight (TOF) mass spectroscopy for positive identification of the barium decay product.