plutonium trigger

English Thesaurus

1. a steel or beryllium sphere containing plutonium 239 that triggers nuclear fission when compressed by explosives (noun.artifact)

hypernym	:	trigger,
definition	:	a device that activates or releases or causes something to happen (noun.artifact)

part meronym	:	a-bomb, atom bomb, atomic bomb, fission bomb, plutonium bomb,
definition	:	a nuclear weapon in which enormous energy is released by nuclear fission (splitting the nuclei of a heavy element like uranium 235 or plutonium 239) (noun.artifact)