Editing Prompt criticality (section)

== Nuclear weapons ==
{{main article|Nuclear weapon design}}
In the design of [[nuclear weapon]]s, in contrast, achieving prompt criticality is essential. Indeed, one of the design problems to overcome in constructing a bomb is to compress the fissile materials enough to achieve prompt criticality before the chain reaction has a chance to produce enough energy to cause the core to expand too much.  A good bomb design must therefore win the race to a dense, prompt critical core before a less-powerful chain reaction disassembles the core without allowing a significant amount of fuel to fission (known as a [[Fizzle (nuclear test)|fizzle]]). This generally means that nuclear bombs need special attention paid to the way the core is assembled, such as the [[Implosion-type nuclear weapon|implosion]] method invented by [[Richard C. Tolman]], [[Robert Serber]], and other scientists at the [[University of California, Berkeley]] in 1942.