Modification of the canonical profile transport model on the basis of new DIII-D experiments

Recent DIII-D experiments have shown that the stiffness of the ion temperature profile κ _i ^PC in the region 0.4 < ρ < 0.7 increases by one order of magnitude with increasing radius. At ρ < 0.4, the stiffness is low and the ion temperature profile is “soft.” The stiffness of the temperature profile also increases with decreasing the toroidal rotation velocity. The approximation of the experimental stiffness profiles allows one to modify the canonical profile transport model. The heat conductivity κ _i ⁰ in the plasma core is determined by minimizing the r.m.s. deviations of the calculated ion temperature from the measured one. This procedure also makes it possible to determine how κ _i ⁰ depends on the central ion temperature.