Varian Medical Systems, Inc.

Varian Medical Systems Technologies, Inc.

Varex Imaging Corporation

James Russell Boye

Gary Fredric Virshup

Gregory C Andrews

Michael C Green

David H Humber

Robert C Treseder

Dennis H Runnoe

Edward J Seppi

Edward G Shapiro

James E Burke

Todd S Parker

Bradley Dee Canfield

Colton Bridger Woodman

John E Richardson

Ricky Burnett Smith

Paul D Moore

Heinrich Riem

Steve Bandy

Charles Lynn Chidester

Clifford K Nishimoto

Paul Gene Christean

Bruce Cain

Stephen G Bandy

Ray Daly

Govin Dasani

Kasey Otho Greenland

Rob Treseder

A cathode head can include: an insulating member on a base; an electron emitter with a planar emitter surface formed by a plurality of elongate rungs connected together through a plurality of turns from a first emitter end to a second emitter end so as to form a serpentine emitter pattern; a plurality of elongate legs extending from the plurality of turns at an angle relative to the planar emitter surface, each of the legs being coupled with the insulating member; an elongate first lead leg at the first emitter end and an elongate second lead leg at the second emitter end; a first electrical lead and a second electrical lead extending from the base; and a first electrical coupler coupling the first electrical lead to the first lead leg and a second electrical coupler coupling the second electrical lead to the second lead leg.

X-ray tube with structurally supported planar emitter

An x-ray tube cathode with magnetic electron beam steering. In one example embodiment, an x-ray tube cathode includes a cathode head and an electron emitter. The cathode head includes electrically conductive and non-magnetic material integrated with magnetic material. The cathode head defines an emitter slot in a portion of electrically conductive and non-magnetic material positioned between two portions of magnetic material. The electron emitter is positioned within the emitter slot. The electron emitter is configured to emit a beam of electrons. The beam of electrons is configured to be both focused by the electrically conductive and non-magnetic material and steered during beam formation by the magnetic material.

X-ray tube cathode with magnetic electron beam steering

Embodiments include an X-ray cathode filament, filament system, process to manufacture the filament and process to use the filament, where the filament includes a planar substrate, such as of tungsten, having a top surface coated with a coating of carburized tungsten (e.g., WC) and thoria (ThO). A first electron beam is emitted from the coating through a thermionic effect at a first temperature, such as when the filament is heated to between 1700 and 1900 degrees Celsius by running an electrical current through the filament. At this temperature, a second electron beam may be caused by (1) a reaction that includes creating thorium (Th) in the coating, and (2) the thorium diffusing to uncoated surfaces of the substrate from which the second electron beam is emitted. The filament may also have slots forming a zipper shape, forming a square switchback shape, or forming a rectangular labyrinth shape to reduce the current required to heat the filament.

Filament for X-ray cathode

Dual-energy x-ray tubes. In one example embodiment, a dual-energy x-ray tube includes an evacuated enclosure, an anode positioned within the evacuated enclosure, a first cathode positioned within the evacuated enclosure, and a second cathode positioned within the evacuated enclosure. The first cathode and the second cathode are configured to operate simultaneously at different voltages.

Dual-energy X-ray tubes

Cathode assembly for a long throw length x-ray tube. In one example embodiment, a cathode assembly for an x-ray tube includes an electron emitter, an acceleration region, and a drift region. The electron emitter includes a curved emitting surface configured to emit an electron beam having a y-dimension that is greater than an x-dimension at the electron emitter. The acceleration region is defined adjacent to the electron emitter. The acceleration region is configured such that when the electron beam propagates within the acceleration region, the electron beam accelerates in a z-direction substantially normal to a midpoint of the curved emitting surface. The drift region is defined between the acceleration region and an anode. The drift region is configured such that the combined lengths of the drift region and the acceleration region are sufficient for the y-dimension to be less than the x-dimension at the anode.

Cathode assembly for a long throw length X-ray tube

An electron emitter assembly for use in an x-ray emitting device or other electron emitter-containing device is disclosed. In one embodiment, an x-ray tube is disclosed, including a vacuum enclosure that houses both an anode having a target surface, and a cathode positioned with respect to the anode. The cathode includes an electron emitter having a plurality of substantially parallel emission surfaces that collectively emit a beam of electrons for impingement on the target anode. In one aspect, the plurality of substantially parallel emission surfaces are angled relative focusing region so as to provide a substantially uniform thermal load on the target anode. In another aspect, the electron emitter includes a plurality of cut-outs that accommodate thermal expansion in the plane of the emitter. Accommodating thermal expansion in the plane of the emitter prevents distortions to the emitter that would tend to alter the focusing of the electrons on the target anode. Providing a substantially uniform thermal load on the target anode and preventing thermal distortion of the emitter lead to higher x-ray flux and better focusing for higher quality x-ray images.

Thermionic emitter designed to provide uniform loading and thermal compensation

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.

Cathode head having filament protection features

A filament assembly for use in an x-ray emitting device or other filament-containing device is disclosed. In one embodiment, an x-ray tube is disclosed, including a vacuum enclosure that houses both an anode having a target surface, and a cathode positioned with respect to the anode. The cathode includes a filament assembly for emitting a beam of electrons during tube operation. The filament assembly comprises a heat sink and a plurality of filament segments. The filament segments are configured for simultaneous emission of an electron beam for impingement on the target surface of the anode, and are electrically connected in series. Each filament segment includes first and second end portions that are thermally connected to the heat sink, and a central portion that can be configured with a modified work function for preferential electron emission.

Filament assembly having reduced electron beam time constant

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.

Shield structure and focal spot control assembly for x-ray device

A multiple energy x-ray source device is disclosed. Embodiments include a dual x-ray source comprised of two x-ray tubes mounted in separate housings. Each x-ray tube operates at a different power level, and each produces a characteristic x-ray signal. The x-ray sources are mounted on a common support structure, and are adjustable with respect to one another and with respect to the support structure so as to provide the ability to precisely align the focal spot of the x-ray signal emitted by each. Interconnection of the x-ray sources is provided by way of interlocking beam shields affixed to each source.

Multiple energy x-ray source assembly

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.

Asymmetric flattening filter for x-ray device

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.

Shield structure for x-ray device

An X-ray generation apparatus has a housing comprising an evacuated envelope with a rotatable anode target surrounded by an all metal grounded exterior structure and a cooling system. The cooling system comprises a coolant circulating system with heat exchanger and means for circulating a fluid coolant through an interior of the X-ray generating apparatus; a hollow shield structure with center aperture for passing and electron beam; and a cooling block which is disposed proximate to the rotatable anode target and comprises a disk with a plurality of concentric annular channels formed by concentric annular partitions. The shield structure and the disk of the cooling block are made of thermally conductive material. An interior of the shield structure is filled with structures such as pins, fins or pack bed which are made of thermally conductive materials. The fluid coolant is circulated through the shield structure, then into the plurality of channels of the cooling block and via an interior of the housing to the heat exchanger for efficient cooling of the X-ray generating apparatus.

Growing community of inventors

Salt Lake City, UT, United States of America

James Russell Boye