prompt-critical
A scientist carefully monitors the prompt-critical state of the reactor core.
Definition
- Adjective (Physics):
- Describing a state of criticality that occurs instantaneously: In nuclear physics, "prompt-critical" refers to a condition in a nuclear reactor or fissile assembly where the chain reaction is sustained solely by prompt neutrons (those released immediately during fission), without relying on delayed neutrons. This leads to an extremely rapid and potentially uncontrolled increase in power.
Usage Examples
- (The chain reaction became self-sustaining using only prompt neutrons, leading to a rapid escalation.)
- (Designers prevent instantaneous criticality to maintain control over the nuclear reaction.)
Advanced Usage
- "prompt-critical accident": An incident where a nuclear assembly becomes prompt-critical, often resulting in a rapid release of energy.
- The 1946 Demon Core experiments involved a prompt-critical accident that killed physicist Louis Slotin. (A sudden, uncontrolled chain reaction occurred due to prompt neutrons.)
Variants and Related Words
- Prompt-criticality (noun): The state or condition of being prompt-critical.
- Prompt-criticality is a key concept in nuclear reactor safety analysis. (The condition where delayed neutrons are not needed for the chain reaction.)
Synonyms
- Immediate criticality: A synonymous term emphasizing the instantaneous nature of the critical state.
- Super-prompt criticality: A more specific term for conditions exceeding prompt-criticality, leading to power escalation.
Related Idioms
- Gone prompt-critical: Informal phrase used in nuclear engineering to describe an uncontrolled chain reaction.
- If the control rods are withdrawn too quickly, the reactor could go prompt-critical. (The reactor may reach a dangerous, self-sustaining state.)