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Penning collisions in a cold gas of trapped metastable helium atoms

We report progress on an experiment on trapped metastable /sup 4/He(2/sup 3/S/sub 1/) atoms which aims at producing a dense gas of ultra cold atoms, with the goal of reaching Bose-Einstein condensation. We have built a magneto-optical trap (MOT) in which we study the cold collisions, which are the main loss cause limiting the obtainable density.