At Los Alamos, physicist Robert Serber proposed that instead of relying on spontaneous fission, the chain reaction inside the atomic bomb should be triggered by a neutron initiator. The best - known neutron sources were radium - beryllium and polonium - beryllium. The latter was chosen, as polonium has a 138 - day half - life, which made it intense enough to be useful but not long - lived enough to be stockpiled. Thomas took charge of the development of techniques to industrially refine polonium for use with beryllium in the "urchin '' internal neutron initiators. This effort became the Dayton Project.
who invented the trigger for the atomic bomb
Robert Serber