Abstract: An x-ray tube (20) includes an evacuated envelope (26). Mounted within the evacuated envelope are a cathode (23) and a rotatbly supported anode (30). A rotor (70) is included for rotatably driving the anode. The rotor (70) is electrically insulated from the anode (30) by a disk (76) comprised of an insulating material.

Abstract: A metal frame x-ray tube (1), includes a gettering system (90) which, when activated, provides a layer (147) of gettering material (98) on a grounded conductive portion (72, 74) of a metal frame or envelope (14). The envelope defines an evacuated chamber (12), which houses an anode (10) and a cathode (18). Moving the gettering material to larger diameter portions of the frame enables substantially larger amounts of gettering material to be provided than in a conventional gettering system, which is typically housed in the cathode assembly (26). Moreover, multiple independently controllable gettering wires (92, 94) facilitate reactivating the gettering material plural times both during the manufacturing process and in the field. This ability to rejuvenate vacuum pumping capability in an x-ray tube that is starting to arc in the field allows for extended x-ray tube life.

Abstract: An x-ray system 20 includes an x-ray tube insert (24) that has an evacuated envelope (34), an anode assembly (38) and a cathode assembly (40). The anode assembly (38) and the cathode assembly (40) are located in operative relationship to one another within the evacuated envelope (34). A temperature indicating member (100) is located in thermally conductive contact with at least one assembly (38, 40, 66) located in the x-ray tube insert (24). The temperature indicating member (100) has a temperature sensitive characteristic which changes in response to adequate thermal exposure to at least one temperature threshold value.

Abstract: A rotation monitoring system (70) detects the rotational speed of an anode (10) of an x-ray tube during use. The system (70) includes a detector (72), which detects a pulse of secondary x-rays generated by the interaction of a stream (C) of electrons with a known defect (83) on a surface (84) of the anode. The detector may be position inside or outside a vacuum envelope (14) of the x-ray tube. The stream of electrons is supplied by a secondary source (80), separate from a main source (18) of electrons used to generate the primary or working x-ray beam (B) of the x-ray tube. A single pulse is detected with each rotation of the anode, providing a simple method of calculation of the anode rotation speed. Preferably, a feed back loop is used to correct the rotational speed of the anode so that overheating of the anode is avoided and the useful life of the x-ray tube is extended.

Abstract: An x-ray tube (20) comprising a cathode (23) and an anode (24) in operative relationship with the cathode (23). The anode (24) is mounted on a stem (32). The x-ray tube includes at least one bearing (58) rotatably receiving the stem (32). The at least one bearing (58) has an outer bearing race (66) in an outer race member, an inner bearing race (62) and a plurality of bearing members (64) operatively disposed between the inner and outer bearing races. The x-ray tube (20) also includes an evacuated envelope (78) which encloses the tube components and receives the outer race member of the at least one bearing (58) in thermally conductive contact along an inner surface (79).