Neutron bomb

A neutron bomb, or enhanced radiation weapon (ERW), is a type of nuclear weapon designed specifically to release a large portion of its energy as energetic neutron radiation rather than explosive energy. Although their extreme blast and heat effects are not eliminated, it is the enormous radiation released by ERWs that is meant to be a major source of casualties. Such radiation is able to penetrate buildings and armored vehicles to kill personnel that would otherwise be protected from the explosion.

Detailed description

An ERW is a fission-fusion thermonuclear weapon (hydrogen bomb) in which the burst of neutrons generated by a fusion reaction is intentionally allowed to escape the weapon, rather than being absorbed by its other components. The weapon's X-ray mirrors and radiation case, made of uranium or lead in a standard bomb, are instead made of chromium or nickel so that the neutrons can escape.d
The term enhanced radiation refers only to the burst of neutron radiation released at the moment of detonation, not to any enhancement of residual radiation in fallout as in the theoretical case of a cobalt bomb.
The "usual" nuclear weapon yield—expressed as kT TNT equivalent—is not a measure of a neutron weapon's destructive power. It refers only to the energy released (mostly heat and blast), and does not express the lethal effect of neutron radiation on living organisms. Compared to a fission bomb with the identical explosive yield, a neutron bomb would emit about ten times^[1] the amount of neutron radiation. In a fission bomb, radiation pulse energy is approximately 5% of entire energy released; in the neutron bomb it would be closer to 50%.