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.)
W41 W41 was the designation of an American nuclear warhead, which was investigated during the late 1950s. Intended for use in the SM-64 Navaho cruise missile, the program was cancelled in 1957. The program was brief, considered at the same time as the TX-29, WX-15-X1 and XW-21 warheads. All were eventually replaced as the proposed Navaho warhead by the W39. The W41 was an adaptation of the B41 thermonuclear bomb which was produced in large numbers and served in stockpile for 15 years.