 Through the 1920s, Arthur Stanley Eddington became a major proponent of the proton–proton chain reaction (PP reaction) as the primary system running the Sun.Neutrons from fusion were first detected by staff members of Ernest Rutherfords' at the University of Cambridge, in 1933.The experiment was developed by Mark Oliphant and involved the acceleration of protons towards a target at energies of up to 600,000 electron volts.