The impact of sawteeth on the Ohmic heating and confinement in a tokamak plasma

The Ohmic power in tokamak plasmas including sawtooth effects is calculated using the neoclassical and Spitzer resistivity models for a particular form of the thermal diffusivity. The radial extent of the sawtooth activity is self-consistently determined and this is dependent on the inverse aspect ratio and the safety factor at the plasma edge. Quantitative results for the neoclassical enhancement over the Spitzer Ohmic power are obtained. In addition the impact of the sawteeth on the energy confinement is calculated.