hyperfine level (F = 3) and confined in a magnetic trap. We measure a
rate similar to 4 x 10(-13) cm(3)s(-1), for a field of 0.1 mT and a te
mperature 1 mu K. This value is 2 orders of magnitude larger than for
lighter alkalis. It puts strong constraints on the trapping mechanism
which could lead to the Bose-Einstein condensation of cesium.