Evidence for fusion heating in the core of a deuterium-tritium (D-T) tokamak plasma is reported for the first time. Electron temperature profile data were analyzed for differences between D-T, D, and T plasmas in the Tokamak Fusion Test Reactor. Data from D and D-T plasmas with similar plasma parameters were averaged to minimize isotopic effects. The electron temperature in D-T plasmas was systematically higher than in D or T plasmas. The temperature difference between D-T and D plasmas with similar confinement times is consistent with alpha-particle heating of electrons.

• Received 28 December 1995

DOI:https://doi.org/10.1103/PhysRevLett.76.2722