Definition

Noun: A plutonium trigger is a core component of a nuclear weapon, specifically a sphere made of steel or beryllium that contains plutonium-239. Its function is to initiate a nuclear fission chain reaction when it is compressed by surrounding conventional explosives.

Usage

The term is used exclusively in the context of nuclear weapons design and technology. It refers to the primary stage or pit that, when imploded, creates the conditions necessary for a nuclear explosion.

Examples

• The scientists carefully assembled the plutonium trigger for the test device.
• The design of the plutonium trigger is critical for achieving a successful nuclear detonation.
• Modern nuclear weapons often use a spherical plutonium trigger as the fission primary.

Advanced Usage

• The term is highly technical and appears primarily in historical accounts, technical manuals, or discussions on nuclear proliferation and arms control.
• It is sometimes referred to more generically as the "nuclear pit" or "fission primary," though these terms can have slightly broader meanings.

Variants and Related Words

• Nuclear trigger: A more general term for any device that initiates a nuclear reaction.
• Fission primary: The initial fission stage in a thermonuclear weapon, which often uses a plutonium trigger.
• Pit: The core element of a nuclear weapon's primary stage, frequently containing plutonium.

Synonyms

• Fission initiator
• Nuclear pit (in specific contexts)
• Atomic trigger (less precise)

Related Phrases

• Implosion device: A type of nuclear weapon design that uses explosives to compress a fissile core like a plutonium trigger.
• Critical mass: The minimum amount of fissile material needed to sustain a chain reaction, a state achieved by compressing the plutonium trigger.

Noun

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