Cathode for high emission x-ray tube
First Claim
1. A method far operating an X-ray source comprising:
- emitting an electron beam along abeam path from an emitter of a cathode;
producing a first dipole field between a backing and an aperture defined by said cathode within said electron beam with a differentially biased cathode and immersing said first dipole field and said differential bias within said electron beam to focus and deflect said electron beam onto a focal spot on an anode to cause X-rays to be emitted from said anode; and
modifying said dipole field with a means for changing the differential bias to shape said electron beam on said anode to effect the focal spot size to produce a predetermined electron beam compression ratio.
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Accused Products
Abstract
A method and apparatus for an x-ray tube having an emitter and a differentially biased emitter-cup cathode configured to provide an electron beam of substantially greater perveance and beam compression ratio than otherwise obtainable with conventional cathode designs is disclosed. The method and apparatus include a cathode assembly opposing an anode and spaced apart therefrom. The cathode is maintained during operation of the x-ray tube at a negative potential with respect to the anode. The cathode assembly includes an emitter for emitting an electron beam to a focal spot on the anode during operation of the x-ray tube and a cathode front member having an aperture defined by the cathode front member on a first side of the emitter. A backing is disposed on a second side of the emitter and is operably connected to the cathode front member via a backing insulator. The cathode further includes a means for applying a differential bias in the cathode assembly to variably change the focal spot size.
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Citations
27 Claims
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1. A method far operating an X-ray source comprising:
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emitting an electron beam along abeam path from an emitter of a cathode;
producing a first dipole field between a backing and an aperture defined by said cathode within said electron beam with a differentially biased cathode and immersing said first dipole field and said differential bias within said electron beam to focus and deflect said electron beam onto a focal spot on an anode to cause X-rays to be emitted from said anode; and
modifying said dipole field with a means for changing the differential bias to shape said electron beam on said anode to effect the focal spot size to produce a predetermined electron beam compression ratio. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method to focus high beam currents of electron emission in a cathode assembly opposing an anode and spaced apart therefrom into different sized focal spots in an x-ray tube, the method comprising:
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biasing components of the cathode assembly independently, wherein the components include;
an emitter situated therein for emitting an electron beam to a focal spot on the anode during operation of the x-ray tube, a cathode front member having an aperture defined by the cathode front member on a first side of the emitter, and a backing disposed on an opposite second side of the emitter and connected to the cathode front member via a backing insulator, wherein the cathode front member and backing are independently biased producing a first dipole field between said backing and said aperture defined by said cathode front member immersing said emitter in said first dipole field within said electron beam to shape and accelerate the electron beam and guide the electron beam to the focal spot on the anode. - View Dependent Claims (13, 14)
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15. An x-ray tube cathode comprising:
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a cathode assembly opposing an anode and spaced apart therefrom, the cathode being maintained during operation of the x-ray tube at a negative potential with respect to the anode, the cathode assembly comprising;
an emitter situated therein for emitting an electron beam to a focal spot on the anode during operation of the x-ray tube, a cathode front member having an aperture defined by the cathode front member on a first side of the emitter, a backing disposed on an opposite second side of the emitter operably depending form the cathode front member via a backing insulator, wherein the aperture of the cathode front member and backing are independently biased producing a first dipole field between said backing and said aperture defined by said cathode front member immersing said emitter in said first dipole field within said electron beam to shape and accelerate the electron beam and guide the electron beam to the focal spot on the anode. - View Dependent Claims (16, 17, 18, 19, 20, 21)
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22. A cathode for x-ray tube comprising:
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a cathode assembly opposing an anode and spaced apart therefrom, the cathode being maintained during operation of the x-ray tube at a negative potential with respect to the anode, the cathode assembly comprising;
an emitter situated therein for emitting an electron beam to a focal spot on the anode during operation of the x-ray tube, a cathode front member having an aperture defined by the cathode front member on a first side of the emitter, a banking disposed on a second side of the emitter and operably connected to the cathode front member via a backing insulator, and a means for applying a differential bias in the cathode producing a first dipole field between said backing and said aperture defined by said cathode front member immersing said emitter in said first dipole field within said electron beam to variably change the focal spot size. - View Dependent Claims (23, 24, 25, 26, 27)
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Specification