Cathode head with focal spot control
AssigneeVarian Medical Systems Technologies, Inc.
InventorRicky Smith
Life of this patent
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Abstract
A cathode head is provide that is suitable for use in an x-ray device that includes an anode having a target surface configured and arranged to receive electrons emitted by the cathode head. The cathode head may be constructed of magnetic or non-magnetic material and includes an emitter block carrying a filament that defines a longitudinal axis about which is disposed one or more magnetic coils. The filament is configured and arranged to emit an electron beam that defines a focal spot on the target surface of the anode. The magnetic coil, or coils, disposed about the longitudinal axis defined by the filament generate a magnetic field that enables control of the location of the focal spot on the target surface of the anode.
Claims35
A cathode head suitable for use in an x-ray device and the cathode head comprising:
- an emitter block;
- an emitter attached to the emitter block and configured to generate electrons of an electron beam, at least a portion of the emitter being positioned within the emitter block, and
- at least one magnetic element that defines an opening within which a portion of the emitter is positioned.
A cathode head suitable for use in an x-ray device and comprising:
- a magnetic emitter block;
- an emitter attached to the emitter block and configured to generate electrons for an electron beam that defines a focal spot;
- and
- means for facilitating focal spot control, wherein the means generates a magnetic field with a magnetic flux density B having flux lines that are substantially perpendicular to a direction of travel of the electron beam.
An x-ray device, comprising:
- a vacuum enclosure;
- an anode substantially disposed within the vacuum enclosure, the anode including a target surface;
- and
- a cathode head comprising the following elements, each of which is substantially disposed within the vacuum enclosure:
- an emitter block;
- an emitter attached to the emitter block and configured to emit electrons of an electron beam that defines a focal spot on the target surface of the anode;
- and
- at least one magnetic element that defines an opening within which a portion of the emitter is positioned.
A cathode head suitable for use in an x-ray device and comprising:
- an emitter block;
- a filament attached to the emitter block and defining a longitudinal axis, the filament being configured to emit electrons of an electron beam;
- and
- first and second magnetic elements that define respective openings within which the emitter block is positioned.
A cathode head suitable for use in an x-ray, the cathode head comprising:
- a magnetic emitter block;
- an emitter attached to the magnetic emitter block;
- and
- at least one magnetic element arranged such that flux lines of a magnetic flux density B of a magnetic field associated with the at least one magnetic element are substantially perpendicular to a direction of travel of the electron beam.
Dependencies are inferred from the claim text.