摘要:
In an X-ray tube having an anode supported for rotation and an annular target track mounted upon the anode, a cathode spaced apart from the anode projects a beam of electrons onto the target track within a focal spot. The cathode is designed to normalize the impact temperature across the focal spot, as a function of length. In accordance therewith, the cathode comprises a filament and a cathode cup, wherein the filament is disposed to project the electron beam onto the target track to generate X-rays, when a high voltage potential difference is established between the filament and the anode. The filament and the cathode cup are respectively configured to selectively form the electron beam so that the beam provides an electron distribution within the focal point which maintains each point within the focal spot at substantially the same temperature.
摘要:
An apparatus for determining the quality of X-ray tubes by analyzing filmed images of the focal spots produced by the tubes. In an exemplary embodiment of the apparatus, a slide scanner receives a filmed focal spot from an X-ray tube and scans it to produce a digital version of the focal spot. The digital focal spot is then analyzed by a personal computer to determine parameters relating to the focal spot such as its background and peak optical density, line spread function, modulation transfer function, skew, and loading. These parameters are then compared to parameter standards to determine whether the X-ray tube should be accepted or rejected under current quality standards.