OBSERVATION OF SAWTOOTH REDISTRIBUTION OF NONTHERMAL, CONFINED ALPHA-PARTICLES IN TFTR DT DISCHARGES

Radial profiles of the density of confined alpha particles with energi es in the 0.15 to 0.6 MeV range are spectroscopically observed before and after a sawtooth crash in a TFTR deuterium-tritium plasma. A large drop in the core alpha density is seen, indicating expulsion of alpha s from the core to the plasma periphery. The measured changes in the a lpha density profiles are consistent with predictions based on the Kol esnichenko sawtooth model in this case.