The Enriched Xenon Observatory is an experiment in the search of the neutrinoless
double beta decay of 136Xe. A positive observation and measurement of the decay
rate would determine fundamental properties of the neutrinos, such as their nature
(Majorana or Dirac) and their absolute mass scale.

The identification of the barium daughter product of the decay via laser induced
fluorescence would allow a background free measurement of the process and would
improve the detection sensitivity to reach neutrino masses on the order of 10 meV.
As one of the main components of the barium
tagging concept in gaseous xenon, a
mass spectrometry system consisting of ion extraction, transport, mass identification
and counting devices was designed, developed and characterized for this work. The
implementation of a nanoelectrospray ionization source coupled to micron sized insulated
nozzles for ion extraction from high pressure gas into vacuum of both singly
and doubly charged states of barium was demonstrated.