critical mass(redirected from Supercriticality)
Also found in: Dictionary, Thesaurus, Medical, Financial.
critical mass:see chain reactionchain reaction,
self-sustaining reaction that, once started, continues without further outside influence. Proper conditions for a chain reaction depend not only on various external factors, such as temperature, but also on the quantity and shape of the substance undergoing the
..... Click the link for more information. .
the smallest mass of a fissionable substance at which a self-sustaining fission chain reaction of atomic nuclei can occur; it is characterized by the approach of the neutron multiplication factor to 1. The corresponding dimensions and volume of the device in which a chain reaction takes place are also called critical.