Definition

Noun: The emission of electrons from a solid surface (typically a metal or semiconductor) caused by the application of a very strong external electric field. This process occurs without the material being heated and involves electrons tunneling through the potential barrier at the surface.

Usage

This is a technical, uncountable noun used primarily in physics and engineering contexts, such as discussions of electron microscopy, vacuum electronics, and nanotechnology. - Field emission is a key principle behind the operation of scanning electron microscopes. - The sharp tip of the cathode enhances field emission. - Researchers are studying materials that exhibit efficient field emission at low voltages.

Advanced Usage

• Field emission display (FED): A type of flat-panel display technology that uses field emission electron sources to illuminate phosphors.
• Cold cathode field emission: A cathode that emits electrons primarily via field emission, as opposed to thermionic emission (which requires heating).
• Field emission gun (FEG): An electron source in scientific instruments that utilizes field emission to produce a bright, coherent electron beam.

Variants and Related Words

• Field emitter (noun): The source or device from which field emission occurs.
• Field-emission (adjective): Used as a modifier, e.g., , .

Synonyms

• Cold emission (This synonym emphasizes the lack of heating involved in the process.)

Related Phrases and Concepts

• Quantum tunneling: The quantum mechanical phenomenon that underlies field emission, where electrons pass through a classically forbidden barrier.
• Fowler-Nordheim equation: The fundamental theoretical equation that describes the current density in field emission.
• Thermionic emission: A contrasting process where electrons are emitted from a heated material.

Noun

1. the emission of electrons that are stripped from parent atoms by a high electric field