useful beam
Also found in: Dictionary, Thesaurus, Encyclopedia.
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.
useful beam
(in radiology) that part of the primary radiation that is permitted to emerge from the tube head assembly of an x-ray machine, as limited by the aperture or port and accessory collimating devices.