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Fiber Optics Illustrated Dictionary - Part 31

The Fiber Optics Illustrated Dictionary - Part 31 fills a gap in the literature by providing instructors, hobbyists, and top-level engineers with an accessible, current reference. From the author of the best-selling Telecommunications Illustrated Dictionary, this comprehensive reference includes fundamental physics, basic technical information for fiber splicing, installation, maintenance, and repair, and follow-up information for communications and other professionals using fiber optic components. Well-balanced, well-researched, and extensively cross-referenced, it also includes hundreds of photographs, charts, and diagrams that clarify the more complex ideas and put simpler ideas into their applications context | Fiber Optics Illustrated Dictionary field coil or coils rather than a permanent magnet. A dynamometer functions through a rotating coil controlled by the interaction between the magnetic fields of a moving coil and field coil s . It can be used in conjunction with both direct current DC and alternating current AC . See D Arsonval galvanometer dynode In a photomultiplier tube a component that enables the amplification of a signal through secondary emission by the stimulation of the release of additional electrons when it is struck by the photoconverted electron s . It is made of reflective materials that will give up electrons and may be coated to improve its properties. Fabrication materials include BeCu beryllium copper and CsSb cesium antimony . A chain of several dynodes is placed in the path of the electrons emitted by a photocathode as they travel towards the anode in an evacuated electron tube. Typically about 10 or 12 dynodes are staggered in pairs at appropriate reflecting angles so that the electron path passes directly from one to the next in the path. The potential of each dynode is set relative to the potential of the next dynode in the chain as each step has a multiplying effect on the energy as a whole gain . As electrons strike the reflective material of the dynode kinetic energy is transferred to the secondary electrons. The kinetic energy is determined by the voltage level of each dynode with a relationship between the kinetic energy and the number of secondary electrons. Higher voltages within operating ranges result in higher numbers of secondary electrons with a cumulative effect as the number of dynodes in the chain increases. Some tubes are suitable for use with a photomultiplier tube base that augments the capabilities of the tube and may provide external voltage stabilization capabilities for the last dynodes in the chain and adjustment control for individual dynodes e.g. the focus dynode . Linear output from a connecting dynode e.g. the 9th