Variable yield
From Wikipedia, the free encyclopedia
Variable yield, or Dial-a-yield, an option available on most modern nuclear weapons, allows the operator to specify a weapon's yield, or explosive power, allowing a single design to be used in different situations.
Dial-a-yield can be achieved with fusion neutron boosting. This can be accomplished by injecting a few milliliters of deuterium-tritium (DT) gas into the vacuum of a hollow core pit inside of a fission-type nuclear weapon. When the dial is turned it may open a valve that will inject a little bit of DT gas into the core of the device. Then the atomic core is plugged, and the high-explosive trigger is assembled.
One weapon that may use this approach is the W88 warhead currently used on American SLBMs. The W-88 with fresh tritium inside its pit may explode with a yield of 475 kilotons, but with no tritium inside the core it might explode with the force of just 20 kilotons. See the nuclear weapons archive to obtain more detailed information on fusion neutron boosting.
Tritium has to be bred in nuclear fission reactors and its half-life is only 12.32 years. Most modern nuclear weaponeers now realize that any dependency on fusion neutron boosting is a nuclear weapon design flaw because of the extreme undersupply of tritium gas since about 1990.[citation needed]
