A numerical measure of a critical mass is dependent on the [http://en.wikipedia.org/wiki/Nuclear_chain_reaction#Effective_neutron_multiplication_factor effective neutron multiplication factor k], the [[average]] number of neutrons released per fission [[event]] that go on to cause another fission event rather than being [[absorbed]] or leaving the material. When k = 1, the [[mass]] is ''critical'', and the chain reaction is barely self-sustaining. | A numerical measure of a critical mass is dependent on the [http://en.wikipedia.org/wiki/Nuclear_chain_reaction#Effective_neutron_multiplication_factor effective neutron multiplication factor k], the [[average]] number of neutrons released per fission [[event]] that go on to cause another fission event rather than being [[absorbed]] or leaving the material. When k = 1, the [[mass]] is ''critical'', and the chain reaction is barely self-sustaining. |