cold cathode

Thân thiện

A technician examines a cold cathode inside a vacuum tube.

Definition

1. Noun:
   • A cathode that emits electrons without requiring heating: A "cold cathode" is a type of cathode, or negative electrode, that functions as a source of electrons without the application of external heat. This distinguishes it from thermionic cathodes, which must be heated to release electrons.

Usage Examples

• Noun:
  • The device utilizes a cold cathode to generate the electron beam.
  • Cold cathode fluorescent lamps (CCFLs) were commonly used for backlighting in older LCD screens.
  • The experiment compared the efficiency of a thermionic emitter to that of a cold cathode.

Advanced Usage

• Technical Context: The term is primarily used in physics and electrical engineering to describe electron emission mechanisms like field emission or secondary emission, where a strong electric field or particle impact, rather than heat, liberates electrons.
  • Field emission displays rely on a matrix of microscopic cold cathodes.

Variants and Related Words

• Cold cathode tube/light/lamp: A tube or lamp that uses a cold cathode to produce light, such as in neon signs or some types of backlights.
  • The vintage clock had a cold cathode tube display.

Synonyms

• Field-emission cathode: Specifically refers to a cold cathode where electrons are emitted via a high electric field.
• Non-thermionic cathode: A broader technical term emphasizing the lack of heating.

Related Phrases

• Cold cathode ionization gauge: A type of vacuum gauge that uses a cold cathode.
• Cold cathode emission: The process of electron emission from a cold cathode.

Học thuật

Noun

1. a cathode that is a source of electrons without being heated