Core Transport Properties in JT-60U and JET Identity Plasmas

The paper compares the transport properties of a set of dimensionless identity experiments performed between JET and JT-60U in the advanced tokamak regime with Internal Transport Barrier, ITB. These International Tokamak Physics Activity, ITPA, joint experiments were carried out with the same plasma shape, toroidal magnetic field ripple and dimensionless profiles. Similarities in the ITB triggering mechanisms and sustainment were observed when a good match was achieved of the most relevant normalized profiles except the toroidal Mach number. Similar thermal ion transport levels have been measured in either monotonic or non-monotonic q-profiles. On the contrary, differences between JET and JT-60U were observed on the electron thermal and particle confinement in reversed magnetic shear configurations. The large shear reversal in the center of JT-60U plasmas allowed the sustainment of stronger electron density ITBs compared to JET. As a consequence of peaked density profile, the core bootstrap current density is more than five times higher in JT-60U compared to JET and reversed magnetic shear configurations are self-sustained in JT-60U scenarios.
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