How many existing basic design types are there of the weapons the United States and the Soviet Union had an arms race over?
Nuclear weapon design Nuclear weapon designs are physical, chemical, and engineering arrangements that cause the physics package of a nuclear weapon to detonate. There are three existing basic design types. In many existing designs, the explosive energy of deployed devices is derived primarily from nuclear fission, not fusion. (This includes fission of any U-238 tamper or casing due to fusion produced neutrons.)
Tsetse (nuclear primary) The Tsetse was a small American nuclear bomb developed in the 1950s that was used as the "primary" in several US thermonuclear bombs and as a small stand-alone weapon of its own. Primary is the technical term for the fission bomb component of a fusion bomb, used to start the reactions and implode and detonate the second, fusion stage.