  EXO is a search for neutrinoless double beta decay in 136Xe. An active R&D
program for a 10 ton, enriched 136Xe liquid phase detector is now underway.
Current research projects are: decay product extraction, Xe purity studies,
energy resolution studies, and Ba+ ion laser-tagging. By extracting and
laser-tagging the Xe decay product (136Ba) and optimizing the energy resolution
in liquid Xe, half lives of up to 5.0x10^28yr will be ultimately probed,
corresponding to a sensitivity to Majorana n masses > ~10meV.
