TFTR Experiments with 2% Tritium Beam Fueling
Author: D.L. Jassby, J.D. Strachan, M.G. Bell, R.V. Budny, L.R. Grisham, K.W. Hill, L.C. Johnson, S.J. Zweben, C.W. Barnes, and M. Loughlin
Tritium has been injected into TFTR supershots using a gas feed containing 2% T and 98% D in one or more neutral beam sources. A total of 38 beam-injected tritium shots required about 400 Curies of tritium, of which less than 5% actually entered the plasma. The ratio of D-T to D-D neutron rates varied from about 0.5 to 4.5. A peak neutron rate of 7.7 x 1016 D-T n/s together with 1.7x1016 D-D /s was attained with eight 2%-T beams deliving 18.7 MW. The measured D-T neutron rates are extrapolated to fusion pwoers in 50:50 D-T operation with similar plasma parameters. The experiments have also provided data for the D-T calibration of neutron an lost-alpha detectors and for optimizing tritium beam injection. With the aid of a multi-channel neutron collimator, these experiments have enabled the comparison of radial profiles of D-T neutron production and global output with the predictions of simulation codes, and contributed to the determination of radial transport coefficients of tritons.