Stalin and the Bomb

by David Holloway

The distinction between the boosted fission weapon and the superbomb is crucial in the history of the United States program. The boosted weapon is one in which a fission bomb is used to initiate a small thermonuclear reaction so that the neutrons from this reaction might increase the efficiency of the use of the fissile material. The idea of the superbomb, on the other hand, was to use a fission bomb to ignite a very large mass of thermonuclear fuel, in order to produce a very large explosive yield on the order of 1,000 times more powerful than the atomic bomb.38 Oppenheimer had advocated the boosted fission bomb as early as 1944, on the grounds that it would provide “an experimentally possible transition from a simple gadget [a fission bomb] to the super and thus open the possibility of a not purely theoretical approach to the latter.”39 Now, in 1948, it was planned to proceed with this work at Los Alamos and to test a boosted weapon in 1951.40 This test was conducted on May 24, 1951; it produced an explosive yield of 45.5 kilotons.41