Ohmic heating of tokamaks

Ohmic heating in present generation tokamaks has proven to be efficacious to the extent that it raises the electron temperatures into the keV range and ion temperatures to several hundred of eV. The ultimate temperatures reached have been dictated by the energy confinement time which at present is relatively short. This restriction should be relaxed in future devices in which the discharge duration will be comparable to the confinement time so that the ohmic heating rate should be primarily set by the thermal capacity of the plasma. If this proves to be the case, and if the current density profile can be suitably chosen, ohmic heating will provide a continual slow increase in plasma temperature throughout the discharge duration.