Identity Physics Experiment on Internal Transport Barriers in JT-60U and JET
A series of experiments have been carried out in 2008 at JT-60U and JET in order to find common characteristics and differences in Internal Transport Barriers (ITBs) observed. The identity experiments succeeded in matching the profiles of most dimensionless parameters at the time ITBs were triggered. Thereafter the q-profile development deviated due to differences in non-inductive current profile, affecting the ITB. Furthermore, the ITBs in JET were found to be more strongly influenced by the H-mode or ELM conditions. It was found to be more difficult to match the plasma rotation characteristics in both devices. However, the wide range of Mach number obtained in these experiments showed to have little effect on the triggering of ITBs in plasmas with reversed magnetic shear. But the toroidal rotation and more specifically the rotational shear had an impact on the subsequent growth and allowed the formation of strong ITBs.