Confinement regimes in ohmically and auxiliary heated tokamaks

The confinement behaviour of ohmically and beam heated tokamaks is described. Anomalous electron thermal transport is dominating in low density ohmic as well as ''L'' and ''H'' type beam heated plasmas. It leads however for these regimes to different scaling laws of both the local thermal conductivities and the global energy confinement times, which are derived from the results of numerous experiments. At high density ohmic discharges the neoclassical ion heat conductivity dominates the energy balance. Though the particle diffusion is anomalous, convective energy losses are small. Extrapolation to tokamak reactor systems indicates a necessity to reach the high confinement ''H''-mode found in beam heated divertor tokamaks for achieving sufficiently high antin . tausub(E) values