 Ernest Thomas Sinton Walton

Ernest Walton and John Cockcroft produced nuclear reactions with a controlled beam of electrically accelerated protons. Their 1932 lithium experiment detected energetic alpha particles from the target. The apparatus made both the incident proton energy and the outgoing reaction products experimentally accessible, replacing reliance on naturally emitted projectiles alone. The result demonstrated how accelerator control could be used to investigate the binding and transformation of atomic nuclei.^[ref]

A physicist.^[ref][ref]