Currently, fusion reactions are carried out in a device known as a tokamak
Major steps forward in this direction were taken recently here and in the U.K. In the U.S., researchers increased the efficiency of the process by adding a third element – in this case, helium-3 ions. The research was published last summer in Nature Physics
Meanwhile, in the U.K., a private company known as Tokamak Energy built a machine with a smaller donut hole, which in 2015 sustained a plasma reaction for a record-breaking 29 hours. Their latest model, the ST40
There is still a long road ahead and many problems to be solved before sustainable nuclear fusion becomes economically feasible – but recent breakthroughs are promising to break Big Oil’s stranglehold over the planet within our lifetimes.
and ... https://www.tokamakenergy.co.uk/
(sorry for the weird fonts and links-- this editor is unpredictable and inconsistent and I have no time to screw with the HTML or strip the original)