Despite the continuing secrecy surrounding the development of the atomic bomb, it is public knowledge that Edward Teller (1908-2003), a Hungarian physicist, worked on the Manhattan Project to produce the first atomic bomb based on uranium fission. Teller had long been interested in a hydrogen fusion bomb, but secrecy and the lack of access to computers contributed to slow progress.
Stanislaw Ulam (1909-1984),a Polish mathematician, realized that a fission bomb could be used as a trigger for a fusion reaction. It is believed that Teller seized on this for what became, in T951, the "Teller-Ulam" design.
Most sources agree that the H-bomb works in a series of stages, occurring in microseconds, one after the other. A narrow metal case houses two nuclear devices separated by polystyrene foam. One is ball shaped; the other is cylindrical. The ball is essentially a standard atomic fission bomb. When this is detonated, high-energy radiation rushes out ahead of the blast. It is believed that this radiation is "reflected" by the outer metal case toward the cylindrical secondary nuclear device. The cylinder, made of uranium 235, is crushed by the pressure of the radiation. Inside, deuterium (an isotope of hydrogen) is compressed and heated to the point where it undergoes nuclear fusion. This in turn releases more energy as well as neutrons, which start a further fission chain reaction in the outer uranium 235 of the cylinder and in an inner core of plutonium.
The fission bombs used in World War II had a yield equivalent to 20,000 tons of TNT; Ivy Mike, the first U.S. H-bomb test in November, 1952, is thought to have had the power of 10,400,000 tons of TNT. Albert Einstein commented, "I don't know what weapons countries might use to fight World War III, but wars after that will be fought with sticks and stones."
