Prompt Critical - Nuclear Weapons

Nuclear Weapons

In the design of nuclear weapons, on the other hand, achieving prompt criticality is essential. Indeed, one of the design problems to overcome in constructing a bomb is to contract the fissile materials and achieve prompt criticality before the chain reaction has a chance to force the core to expand. A good bomb design must therefore win the race to a dense, prompt critical core before a less-powerful chain reaction (known as a fizzle) disassembles the core without allowing a significant amount of fuel to fission. This generally means that nuclear bombs need special attention paid to the way the core is assembled, such as the novel implosion method hypothesized by Richard C. Tolman, Robert Serber, and other scientists at the University of California, Berkeley in 1942.