EXO - The Enriched Xenon Observatory

The Enriched Xenon Observatory (EXO) is a detector for the neutrinoless
double beta decay of 136-Xe into 136-Ba, with a sensitivity to a half life
of up to 5 x 10E28 years. This corresponds to an effective neutrino mass of
< 10 meV. To achieve this limit, conventional radiation detection techniques
are combined with ion spectroscopy, which allows for a quasi background free
measurement. In the first part of the talk an overview of the prototype
detector EXO-200 is given. The detector is a time projection chamber
deploying 200 kg of isotopically enriched 136-Xe as source and as an active
medium. It is currently being commissioned in a shielded and clean
environment at Stanford and is scheduled for installation at the
underground site WIPP in the very near future. The second part of the
presentation deals with R & D on barium ion tagging. Results on single ion
spectroscopy in a linear RFQ trap will be presented and methods of Ba ion
extraction from liquid xenon and manipulation are discussed.