Overview of deuterium-tritium results from JET-ILW experiments

JET has recently completed the first deuterium-tritium (D-T) campaign in a tokamak since 1997, and for the first time ever with ITER-like W/Be divertor and first wall materials. Scientific results include demonstration of high (average P_fus>10 MW) sustained fusion power for 5 s, demonstration of an integrated radiative scenario, demonstration of clear alpha particle effects, exploration of isotope and mixed plasma species effects on energy and particle transport, addressing plasma-wall interaction in D-T plasmas, and demonstration of RF schemes relevant to ITER D-T operation. Highlights include achievement of 42 MJ fusion energy production in a 50/50 D-T plasma pulse and 59 MJ in a deuterium-NBI heated tritium-rich pulse, both surpassing the 1997 record of 22 MJ and demonstrating the compatibility of the ILW with sustained fusion performance. The dependence of P_fus on input power was consistent with pre-experiment predictions, validating predictive capabilities. An integrated scenario with Ne seeding was demonstrated for the first time in D-T with the ILW, with detached divertor conditions and improved energy confinement over reference unseeded plasmas, confirming Ne as a promising radiator for ITER. Improved diagnostics compared to 1997 show variation of pedestal structure depending on D-T fuel mix, with a clear increase in pedestal density and pressure with increasing tritium concentration. Expected increase in erosion observed due to heavier tritium ions, but plasma impurity levels remained tolerable. Alpha-driven modes at Alfvénic frequencies are observed in an afterglow phase with no NBI heating. Efficient core heating demonstrated with 3-ion D-⁹Be-T RF scheme.