Internal Transport Barriers in JET Deuterium-Tritium Plasmas

The observation of internal transport barriers (ITBs) in which ion thermal diffusivity is reduced to a neoclassical level has been made for the first time in tokamak plasmas fueled with deuterium and tritium ions using a broad current density profile. The heating and current profiles required to obtain an ITB are similar in D-T and D-D plasmas. Central ion temperatures of 40 keV and plasma pressure gradients of ${10}^6\mathrm{Pa}/\mathrm{m}$ were observed in a D-T plasma, leading to a fusion triple product $n_i{T}_i{\tau }_E{=1.10\mathrm{}}^{21}{\mathrm{m}}^{-3\mathrm{}}\mathrm{keV}\mathrm{s}$ and 8.2 MW of fusion power. There is potential for further optimization as a step towards the development of efficient tokamak fusion reactors.