Abstract:
A shield structure is provided that is suitable for use in connection with an x-ray device that includes an anode and cathode disposed in a vacuum enclosure in a spaced apart arrangement so that a target surface of the anode is positioned to receive electrons emitted by the cathode. The shield structure is configured to be interposed between the anode and the cathode and includes an interior surface that defines an aperture through which the electrons are passed from the cathode to the target surface of the anode. Additionally, the aperture includes an inlet and an outlet sized so that the area of the inlet is relatively smaller than the area of the outlet. Finally, the shield structure is situated in the x-ray device such that the inlet of the aperture is positioned near the cathode and the outlet of the aperture is positioned near the anode target surface.
Abstract:
A cathode assembly including certain features designed to protect the integrity of a filament contained therein is disclosed. In particular, the cathode assembly is configured to prevent damage to the filament should it inadvertently contact another portion of the cathode assembly. In an example embodiment, an x-ray tube incorporating features of the present invention is disclosed. The x-ray tube includes an evacuated enclosure containing a cathode assembly and an anode. The cathode assembly includes a head portion having a head surface. A slot is defined on the head surface and an electron-emitting filament is included in the slot. A protective surface is defined on the head surface proximate to a central portion of the filament. The protective surface in one embodiment is composed of tungsten and is configure to prevent fusing of the filament to the protective surface should the filament inadvertently contact the protective surface.
Abstract:
A shield structure and focal spot control assembly is provided for use in connection with an x-ray device that includes an anode and cathode disposed in a vacuum enclosure in a spaced apart arrangement so that a target surface of the anode is positioned to receive electrons emitted by the cathode. The shield structure is configured to be interposed between the anode and the cathode and includes an interior surface that defines an aperture or other opening through which the electrons are passed from the cathode to the target surface of the anode. Additionally, fluid passageways defined in connection with the shield structure enable cooling of the shield structure. Finally, a magnetic device disposed proximate the cathode facilitates control of the location of the focal spot on the target surface of the anode.
Abstract:
Devices and methods for implementing selective, or asymmetric, attenuation of an x-ray beam. In one example, a filter is provided that is substantially in the form of a wedge where some portions of the filter are thicker, and thus provide greater attenuation, than other, thinner portions of the filter. The filter is situated between the target surface of the anode and the x-ray subject so that x-rays generated by the target pass through the filter before reaching the x-ray subject. Specifically, the filter is oriented so that the thicker portion of the filter receives the higher intensity portion of the x-ray beam, while the thinner portion of the filter receives the relatively lower intensity portion of the x-ray beam. Thus, the gain profile of the x-ray beam is flattened so that the intensity, or flux, of the x-ray beam is relatively uniform throughout a substantial portion of the beam profile.
Abstract:
A cathode assembly including certain features designed to protect the integrity of a filament contained therein is disclosed. In particular, the cathode assembly is configured to prevent damage to the filament should it inadvertently contact another portion of the cathode assembly. In an example embodiment, an x-ray tube incorporating features of the present invention is disclosed. The x-ray tube includes an evacuated enclosure containing a cathode assembly and an anode. The cathode assembly includes a head portion having a head surface. A slot is defined on the head surface and an electron-emitting filament is included in the slot. A protective surface is defined on the head surface proximate to a central portion of the filament. The protective surface in one embodiment is composed of tungsten and is configure to prevent fusing of the filament to the protective surface should the filament inadvertently contact the protective surface.
Abstract:
A shield structure and focal spot control assembly is provided for use in connection with an x-ray device that includes an anode and cathode disposed in a vacuum enclosure in a spaced apart arrangement so that a target surface of the anode is positioned to receive electrons emitted by the cathode. The shield structure is configured to be interposed between the anode and the cathode and includes an interior surface that defines an aperture or other opening through which the electrons are passed from the cathode to the target surface of the anode. Additionally, fluid passageways defined in connection with the shield structure enable cooling of the shield structure. Finally, a magnetic device disposed proximate the cathode facilitates control of the location of the focal spot on the target surface of the anode.
Abstract:
Devices and methods for implementing selective, or asymmetric, attenuation of an x-ray beam. In one example, a filter is provided that is substantially in the form of a wedge where some portions of the filter are thicker, and thus provide greater attenuation, than other, thinner portions of the filter. The filter is situated between the target surface of the anode and the x-ray subject so that x-rays generated by the target pass through the filter before reaching the x-ray subject. Specifically, the filter is oriented so that the thicker portion of the filter receives the higher intensity portion of the x-ray beam, while the thinner portion of the filter receives the relatively lower intensity portion of the x-ray beam. Thus, the gain profile of the x-ray beam is flattened so that the intensity, or flux, of the x-ray beam is relatively uniform throughout a substantial portion of the beam profile.