Global and local energy transport analysis of experimental results in TFTR and JET indicate that transport models of the Bohm type allow a better representation of experimental data than models of the gyro-Bohm type. Hence a Bohm-like model has been developed by allowing a dependence on a few dimensionless parameters so as to reproduce the main features of global L-mode thermal confinement scaling laws in tokamaks and to obtain bowl-shaped thermal diffusivity profiles. The electron temperature profiles predicted by this model are shown to be in agreement with measured ones in a variety of steady-state and time-dependent JET L-mode discharges.
Modelling of temperature profiles and transport scaling in auxiliary heated tokamaks