ALPHA-PARTICLE LOSS IN THE TFTR DT EXPERIMENTS

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.