Experimental production of a divergent chain reaction

On December 2, 1942, the first self-sustaining chain reaction was successfully initiated in the Chicago Pile-1. In 1939 already, the Italian scientist Enrico Fermi had been awarded the Nobel prize for his work on 'The Possibility of Technical Energy Generation from Uranium Fission'. That work had summarized the results of several research teams. The studies were based on a graphite moderated reactor. The energy released per fission was approx. 200 MeV. (orig.)