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Pumping |
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pumping [′pəmp·iŋ]
(fluid mechanics) Unsteadiness of the mercury in the barometer, caused by fluctuations of the air pressure produced by a gusty wind or due to the motion of a vessel. (physics) The application of optical, infrared, or microwave radiation of appropriate frequency to a laser or maser medium so that absorption of the radiation increases the population of atoms or molecules in higher energy states. Also known as electronic pumping. The removal of gases and vapors from a vacuum system. pumping The displacement and ejection of water and suspended fine particles at joints, cracks, and edges. Pumping (in quantum electronics), the process of creation of a nonequilibrium state of a substance under the action of electromagnetic fields or collisions with charged or neutral particles, upon abrupt cooling of preheated gaseous masses, and so on. Pumping may shift a substance from a state of thermal equilibrium to an active state (with a population inversion), in which it can amplify and generate electromagnetic waves. The term “pumping” has spread beyond the bounds of quantum electronics—it is used in radio engineering and optics to designate the processes by which the active elements of parametric systems are affected. Want to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit the webmaster's page for free fun content. |
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