Extension of a Bohm model for L-mode electron heat transport to ion heat transport and to the ohmic regime

The results of simulations of several JET L-mode and ohmic discharges performed with a Bohm-like expression for both ion and electron thermal diffusivities are presented. Comparisons with experimental ion and electron temperature profiles of auxiliary heated discharges show that xi i has to be at least twice larger than xi e to simulate the L-mode regime even for shots with dominant electron heating. Simulations of ohmic discharges with currents ranging from 1 to 7 MA show that the Bohm-like model for the L-mode is preferable to a neoalcator-like expression of the electron thermal diffusivities.