We have measured the two body loss rate in a magneto-optical trap containin
g triplet metastable He atoms. Mie find a rate constant beta = 3 x 10(-8) c
m(3)/s at a -8 MHz detuning, with an uncertainty of a factor 2. This measur
ement is in disagreement with a recent experiment which measures the absolu
te, ion-producing collision rate, but agrees with several other published m
easurements.