Alpha particle loss was measured during the TFTR DT experiments with a
scintillator detector located at the vessel bottom in the ion del E d
rift direction. The DT alpha particle loss to this detector was consis
tent with the calculated first orbit loss over the whole range of plas
ma current I = 0.6-2.7 MA. In particular, the alpha particle loss rate
per DT neutron at a given plasma current did not increase significant
ly with fusion power up to 10.7 MW, indicating the absence of any new
'collective' alpha particle loss processes in these experiments.