Varian Medical Systems, Inc.

Varian Associates, Inc.

Robert C Treseder

James Russell Boye

Dennis H Runnoe

Gary Fredric Virshup

Michael C Green

James E Burke

Christopher F Artig

George V Miram

David H Humber

Gordon R Lavering

John E Richardson

Paul D Moore

Steve Bandy

Thomas J Koller

Jeffrey Steven Wassom

Thomas J Grant

Robert F Heiting

Brian D Green

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

Finned anode. In one example embodiment, an anode suitable for use in an x-ray tube includes a hub, a front side, and a target surface disposed on the front side. The hub is configured to attach to a bearing assembly and the front side substantially faces the bearing assembly. The anode further includes a rear side substantially opposite the front side, as well as two or more annular anode fins extending from the rear side. The annular anode fins are positioned radially outward from the hub to an outer periphery of the rear side.

Finned anode

An asymmetric x-ray tube. In one example embodiment, an x-ray tube includes an evacuated enclosure, a cathode assembly at least partially positioned within the evacuated enclosure and defining a first axis, and an anode assembly at least partially positioned within the evacuated enclosure and defining a second axis. The anode assembly includes a rotating anode having a focal spot. The focal spot and the second axis define a plane. The first axis is positioned beneath the plane.

Asymmetric x-ray tube

An electron emitter assembly, and methods of assembly, is disclosed. The emitter assembly includes an electron emitter that is secured to a support device in a manner such that the emitter is substantially thermally isolated from the support device.

Electron emitter apparatus and method of assembly

In one example, an x-ray device is provided that includes an enclosure having an x-ray transmissive window. A cathode assembly that includes an electron source capable of emitting electrons is disposed within the enclosure. An anode is also disposed in the enclosure between the cathode assembly and the window. The anode includes a body portion and a target surface that is positioned on the body portion so as to face away from the electron source of the cathode assembly. The anode further includes a drift tunnel that defines a path through which electrons pass from the electron source to the target surface. Finally, this example includes a voltage source electrically connected so as to provide a potential field that causes some of the electrons to impact the target surface and produce x-rays for emission through the window.

Analytical x-ray tube for close coupled sample analysis

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

An X-ray tube device and a method for construction thereof which provides the cathode assembly and the anode assembly in a nose of the X-ray tube, wherein an emitter face of each assembly is directed toward an X-ray emission end thereof. The electrons emitted from the cathode assembly travel along a path outward until striking the anode assembly which then generates the X-rays which are directed toward a beryllium window in the X-ray tube. This advantageous structure enables the anode-to-window distance to be small, resulting in a large X-ray flux towards a sample. Furthermore, the small nose of the X-ray tube enables a fluorescence detector to be positioned in an optimal location because the X-ray tube's shape does not displace the fluorescence detector.

Air cooled end-window metal-ceramic X-ray tube for lower power XRF

The present invention provides an X-ray generating apparatus with a shield structure having an electron beam collimating aperture and heat transfer device. The shield structure is made of thermally conductive material and placed in the discharge space between an electron source and rotating anode target. The shield structure is formed by a concave top surface facing the electron source, a flat top surface facing the anode target, and inner and outer walls wherein a linear dimension of the inner wall is substantially smaller than the linear dimension of the outer wall. The inner wall surrounds the beam collecting aperture. The heat transfer device is placed in a beveled portion of the shield structure. The heat transfer device includes an extended coiled wire formed from thermally conductive material and conductively attached to the knurled interior of the shield structure to transfer heat to the cooling liquid passing through inflow and outflow chambers of the shield structure.

X-ray generating apparatus with a heat transfer device

A heater for an indirectly heated vacuum tube cathode is formed of anisotropic pyrolytic graphite in which current passes through the graphite in the 'c' direction.

Anisotropic pyrolytic graphite heater

A mammography X-ray tube providing increased X-ray intensity for shortening patient exposure times to eliminate motion artifacts. The cathode design permits superpositioning of electron beam from multiple filaments.

Mammography method and improved mammography X-ray tube

An improved metal center rotating anode x-ray tube is shown. The improved x-ray tube includes means for preventing the build-up of charge on the anode glass portion of the tube envelope where the glass flares by constraining the equipotential lines of the electric field in the vicinity of th eflare to parallel the flare surface. Parallelism may be achieved by (1) controlling the angle of the flare and sealing the flare directly to the metal section, (2) modifying the anode rotor to include a flare conforming to the glass flare, and (3) including a ground plane screen in the tube housing.

Metal center x-ray tube

Disclosed are a method and apparatus for rapidly heating a thermionic vacuum tube cathode, thereby enabling the vacuum tube to be placed in useful operation shortly after the tube is switched on. Rapid heating of the cathode is achieved by passing current through the cathode, thereby directly heating it. Simultaneously, the cathode is also heated by an indirect radiant heater and by electron bombardment by electrons emitted from the heater. When the cathode reaches its operating temperature, the direct heating current and the electron bombardment are stopped and the cathode is maintained at its operating temperature by the indirect heater alone. Cathode warm-up times of less than 1 second may be attained using this invention.

Growing community of inventors

Salt Lake City, UT, United States of America

Robert C Treseder