Cobalt bomb

A cobalt bomb is a thermonuclear weapon with an external cobalt casing. When the weapon detonates the neutron flux from the deuterium-tritium reaction converts the ordinary cobalt 59 to intensely radioactive cobalt 60 via a reaction known as neutron activation. This greatly increases the radioactive fallout, and the duration of lethal radiation levels in the fallout zone.

Other reactive casings for thermonuclear weapons have been proposed, and even tested, such as compound fission-fusion-fission weapons. However the cobalt device seems best adapted to use as an enhanced radiation weapon as cobalt 60's 5 year half-life gives a good compromise between duration and radioactive intensity.

It has been suggested, by Dr Leo Slizard, that a large enough number of cobalt bombs could destroy all life on earth, and this possibility has been used as a plot point in the novel ON THE BEACH, and the film DR STRANGELOVE: OR HOW I LEARNED TO STOP WORRYING AND LOVE THE BOMB. Later films such as RETURN TO THE PLANET OF THE APES sometimes mis-represented the cobalt bomb as a weapon of greatly enhanced blast strength, but this popular misconception is entirely untrue.