Predictive Simulations of Impurity Transport at JET
In the present study, the impact of sheared toroidal rotation on L-mode and H-mode experiments with carbon wall at the Joint European Torus are analysed using the coupling between the transport codes JETTO (for main ions) and SANCO (for impurities) for predictive simulations. Transport coefficients due to Ion-Temperature-Gradient (ITG) mode and Trapped-Electron (TE) mode turbulence are used together with neoclassical transport from NCLASS. The transport coefficients obtained using the Chalmers fluid model, updated with the roto-diffusion associated with sheared rotation, are compared with gyrokinetic results using the code GENE. Self-consistent simulations of electron and ion temperatures, main ion and impurity densities are performed while the toroidal momentum profile is treated interpretatively. The role of neoclassical impurity transport is evaluated and the dependence of the simulated profiles on impurity charge number Z, rotation gradient (roto-diffusion), and impurity charge fraction (Zeff) are discussed. In particular the impact of sheared toroidal rotation on the C profiles is investigated. The considered discharges include L-mode impurity injection experiment Pulse No: 67730, as well as a H-mode discharge. The impurity behaviour in the L-mode and H-mode discharges are compared, however, experimental data for the impurity transport coefficients are only available for the L-mode discharge.