X-ray tube for CT applications

摘要

An x-ray tube assembly (16) includes a vacuum envelope (52) and an x-ray permeable exit window (58). An anode (50) is positioned within the vacuum envelope (52) such that a near side is adjacent to the exit window (58) and a far side is opposite thereof. A cathode assembly (66) is also mounted within the vacuum envelope (52) which directs an electron beam (72) toward a focal spot or point (62) on the far side of the anode (50). The anode further includes a central cavity or indentation (70) which provides a location for mounting a set of radiation attenuating vanes (64) in addition to a shaped x-ray filter or compensator (68). Close placement of the vanes (64) and the filter (68) relative to the focal spot of the anode desirably reduce off focal radiation and allow beam shaping. An externally located collimator (18) further shapes the output x-ray beam.