JET-P(98)05
JET Results in D/T Divertor Plasmas
Recent results obtained during the first part of the JET D/T phase are presented. Emphasis is placed in conditions carefully set to be similar to those required in ITER. Wall-loading changeover from 100% deuterium to 90% tritium is achieved in about 20 discharges with 100% tritium injection. H-mode threshold power is found to have inverse isotopic mass dependence whereas there is little mass dependence in global energy confinement time in the ELM-free or ELMy H-mode discharges. Preliminary results are consistent with the gyro-Bohm physics form of global energy dependence. This form has a weak negative mass dependence but a stronger density dependence than the ITERH93-P form. The second harmonic ion-cyclotron resonance heating (ICRH) ITER reference scenario (2ωCT with and without the addition of a small amount of He3) has been assessed in JET D/T plasmas. High performance combined heating (NB+ICRH) hot-ion and optimised shear regime experiments could only be carried out with half the installed NB power. Nevertheless, internal confinement barriers in optimised shear regime have also been demonstrated in D/T plasmas.