TRANSPORT MEASUREMENTS FOR CONFINED NONTHERMAL ALPHA-PARTICLES IN TFTR DT PLASMAS

Fusion produced non-thermal alpha particle radial profile measurements are obtained with the alpha-CHERS diagnostic in deuterium-tritium (DT ) supershot plasmas on the Tokamak Fusion Test Reactor (TFTR). Alpha p articles in the energy range 0.15 less than or equal to E-alpha less t han or equal to 0.6 MeV are observed spectroscopically over a five poi nt radial profile. The extracted non-thermal alpha signal is less than or equal to 1% of the background bremsstrahlung intensity for typical total fast alpha densities in the range (0.5-1.0) X 10(17) m(-3). The profiles obtained in two sets of discharges vary slightly, and are be st described by a slowing down alpha distribution subject to neoclassi cal diffusion plus a small anomalous cross-field diffusion. The data a re consistent with an effective anomalous diffusion coefficient in the range 0.00 less than or equal to D-alpha,D-a < 0.10 m(2)/s, where D-a lpha,D-a is constant with alpha energy and with radius.