useful beam
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beam
[bēm]a unidirectional, or approximately unidirectional, emission of electromagnetic radiation or particles.
useful beam in radiology, that part of the primary radiation that is permitted to emerge from the tubehead assembly of an x-ray machine, as limited by the aperture or port and accessory collimating devices.
beam splitter a device that reflects light from the output phosphor of an image intensifier to a photographic recording. Called also image distributor.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.