Definition

Noun: A device, specifically a type of vacuum tube, that produces a cascading multiplication of electrons to amplify a small initial flow of electrons into a much larger, detectable electrical current.

Usage

The term "electron multiplier" is used to describe a key component in scientific instruments where the detection of very weak signals, such as single particles or photons, is required. It functions by using a series of electrodes (dynodes) to create a chain reaction of secondary electron emission.

Examples

• In a sentence:
  • The mass spectrometer uses an electron multiplier to detect ions with high sensitivity.
  • The signal from the photomultiplier tube, which contains an electron multiplier section, was strong enough to be recorded.

Advanced Usage

• "Continuous-dynode electron multiplier": A specific type where the multiplication occurs along a continuous resistive surface, often shaped like a horn or channel, rather than using discrete dynode stages.
  • The channeltron is a compact form of a continuous-dynode electron multiplier.

Variants and Related Words

• Photomultiplier tube (PMT): A device that combines a photocathode (to convert light into electrons) with an electron multiplier to detect very low levels of light.
• Microchannel plate (MCP): An array of millions of microscopic continuous-dynode electron multipliers used for imaging and fast detection.
• Dynode: One of the series of electrodes within a discrete-dynode electron multiplier that emits secondary electrons.

Synonyms

• Electron amplifier: A less common but descriptive synonym.
• Multiplier: Often used as shorthand in technical contexts (e.g., "the detector's multiplier").

Related Phrases/Compounds

• "Electron multiplication": The physical process that occurs within an electron multiplier.
  • The gain of the detector depends on the efficiency of electron multiplication.
• "Multiplier gain": A measure of the amplification factor provided by the electron multiplier.

Noun

1. a vacuum tube that amplifies a flow of electrons