JET (Joint European Torus) is the biggest operational fusion device in the world.
It is a tokamak but with normal copper magnets, not superconducting.
JET began operation in 1983 and is one of only two fusion devices to have run experiments using deuterium-tritium fuel. These experiment took place in 1997, 2021 and 2023 and their results are shown below. In total the experiments operated with D-T fuel for 20 seconds.JET website