Electron temperatures in excess of 8 keV have been obtained by electron-cyclotron-resonance heating on FTU plasmas at peak densities up to $8\times {10}^{19}\mathrm{m}{}^{-3\mathrm{}}$. The magnetic shear in the plasma core is low or negative, and the electron heat diffusivity remains at, or below, the Ohmic level $(0.2\mathrm{m}{}^2/\mathrm{s})$, in spite of the very large heating power density $(10–20\mathrm{MW}/\mathrm{m}{}^3)$ which produces extremely high temperature gradients (up to 120 keV/m). The ion heat transport remains at the neoclassical level.

Sulfur Recovery from Acid Gas Using the Claus Process and High Temperature Air Combustion (HiTAC) Technology

Studies on the current-drive (CD) efficiency have been carried out in the FTU tokamak with 8 GHz lower-hybrid waves up to line-averaged plasma density ${\overline{n}}_e>1\mathrm{}\times {10}^{20}{\mathrm{m}}^{-3\mathrm{}}$. High efficiencies, larger than $0.2\times {10}^{20}{\mathrm{m}}^{-2\mathrm{}}\mathrm{A}/\mathrm{W}$, are obtained for clean plasma conditions, with no significant degradation as the density is increased up to the accessibility limit. The electron temperature affects favorably the CD efficiency. Impurity influx never limits the machine operations up to the maximum coupled power of 1.7 MW.