Definition

Noun: The rate of flow of neutrons; specifically, the number of neutrons passing through a unit area per unit time. It is a key physical quantity in nuclear physics and reactor engineering, describing the intensity of a neutron field.

Usage

"Neutron flux" is a technical term used primarily in nuclear physics, reactor design, and radiation measurement. It quantifies how many neutrons are moving through a given space. * The neutron flux inside the reactor core must be carefully controlled to maintain a stable chain reaction. * Scientists measured the neutron flux to determine the radiation levels in the experimental chamber. * A higher neutron flux typically leads to a greater rate of nuclear interactions.

Advanced Usage

• Thermal neutron flux: Refers specifically to the flux of neutrons that have been slowed down (moderated) to thermal energies, which are most effective at causing fission in certain fuels like Uranium-235.
• Fast neutron flux: Refers to the flux of high-energy neutrons. This is a critical parameter in fast breeder reactors and for material damage studies.
• Flux shaping: The process of deliberately designing a reactor core to achieve a desired spatial distribution of neutron flux.

Variants and Related Words

• Flux (n): In a general physics context, it means the rate of flow of a property (e.g., particles, energy, fluid) through a given area. "Neutron flux" is a specific type of particle flux.
• Neutron fluence (n): The time-integrated neutron flux; the total number of neutrons that have passed through a unit area over a period of time. While flux is a rate (neutrons per cm² per second), fluence is a total accumulated quantity (neutrons per cm²).

Synonyms

• Neutron current density (in specific technical contexts, though this can have a more specific vector meaning).
• Neutron flow rate (a less common, descriptive synonym).

Related Phrases

• Neutron flux density: Often used interchangeably with "neutron flux," though it can more explicitly emphasize the "per unit area" aspect of the definition.
• To measure/monitor the neutron flux: The standard phrasing for observing this quantity.
• Peak/average neutron flux: Terms used to describe the maximum and mean values of flux within a volume, important for reactor safety and design.

Noun

1. the rate of flow of neutrons; the number of neutrons passing through a unit area in unit time