LHCb, one of the six separate experiments at the Large Hadron Collider, is particularly suited for examining what is called "charge-parity violation" - slight differences in behaviour if a given particle is swapped for its antimatter counterpart (changing its charge) and turned around one of its axes (changing its parity).
The energy released in fusion is carried mostly by neutrons, a type of subatomic particle that has no electric charge and hence cannot be confined by the magnetic bottle.
Working on a theory to combine quantum mechanics with Einstein's special relativity, he realised his equations predicted a corresponding anti-particle for every particle in existence - identical in every respect, but with an opposite electrical charge.