A key aim of the 2021 JET deuterium-tritium (D-T) experiments was to demonstrate steady high fusion power (10-15MW) with the ITER-like Be/W first wall. Plasmas were developed using D, repeated with T to investigate and mitigate isotope effects, and run with D-T to maximise fusion power. Compared with high current (q95~3) ‘baseline’ plasmas, …