[rnhmjoj]

> they basically just need to put them all in a ring and light it up

Well, if that's not under understatement... There are surely many more challenges in the high-field line of research, probably more than we know of, since they're kind of pioneering this field. Large size tokamaks, depsite their huge costs, have some considerable benefits like longer timescales for MHD instabilities and smaller stresses (both thermal and mechanical).