photomultiplier[fōt′ō mul′tə plī′ər]
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio.
a photoemissive photoelectric cell which amplifies emitted electrons and converts them into brighter light, an electric signal, etc.
Used by arrangement with John Wiley & Sons, Inc.
The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
An electronic sensing device used to detect electromagnetic energy of a wide range of frequencies and intensity levels.
photomultiplier - Science Definition
The American Heritage® Science Dictionary
An electrical device designed for the detection of weak electromagnetic radiation, usually light, by amplifying the energy of the photons that strike it into stronger electrical signals. Photomultipliers are used in night-vision technology and in telescopes to detect light not strong enough to be visible by the unaided eye. ♦ The most common photomultiplier is the tube photomultiplier; it exploits secondary emission of electrons in a vacuum tube in the manner of an electron multiplier. When radiation strikes the cathode of a tube photomultiplier, electrons called photoelectrons are emitted and attracted to positively charged electrodes called dynodes. When they collide with the dynode, more electrons are released; these are in turn attracted to another dynode at a higher voltage to release yet more electrons, and so on. At the end of this process, there is a current flow at the anode that is strong enough to be easily detected.
Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.