High duty-cycle x-ray tube
AssigneeImatron, Inc.
InventorsRoy E. Rand, Douglas P. Boyd, Kristian R. Peschmann
Life of this patent
Estimating the term…
Abstract
A rotating x-ray tube includes an electron-beam accelerator assembly having an indirectly heated cathode structure. The cathode structure includes an electron-emitting region mounted at the center of a rotationally symmetric Pierce-cathode configuration. An electron beam travels along a selected path as the tube rotates so that the electron beam strikes selected portions of a target mounted within the tube as it rotates. Two magnetic coils and a ferromagnetic mirror plate are arranged to function as a single quadrupole electromagnet, which has its axis parallel to and offset from the electron beam and which elongates the electron beam in a radial direction.
Claims9
An x-ray tube, comprising:
- an envelope for containing a vacuum;
- target means forming part of said envelope for emitting x-rays;
- an electron-beam accelerator assembly including:
- an indirectly heated cathode assembly having a cathode for emitting electrons;
- a shaped rotationally symmetric electrode surrounding said cathode;
- a primary shaped anode with a central bore spaced from said cathode for accelerating the electrons emitted by said cathode, said shaped electrode and shaped anode providing focusing fields which focus the electron beam to form a beam waist at the center of said bore;
- means external of said envelope for focusing said electron beam leaving the anode on said target means;
- support means external to said envelope for supporting said envelope for rotational movement;
- and
- means external of said envelope for deflecting said electron beam along a selected path as said envelope rotates such that said electron beam strikes selected portions of said target means as it rotates.
An x-ray tube, comprising
- an envelope for containing a vacuum;
- target means forming part of said envelope for emitting x-rays;
- an electron-beam accelerator assembly including:
- an indirectly heated cathode assembly for emitting an electron beam, wherein said cathode means includes an electron-emitting region mounted at the center of a rotationally symmetric Pierce-cathode configuration;
- a primary anode having formed therein an aperture through which the electron beam is accelerated by said anode, said anode and Pierce-cathode forming a beam waist at said aperture;
- means for focusing said electron beam on said target means;
- support means external to said envelope for supporting said envelope for rotational movement;
- and
- means external of said envelope for deflecting said electron beam along a selected path as said envelope rotates such that said electron beam strikes selected portions of said target means as it rotates.
Dependencies are inferred from the claim text.