Moxtek, Inc.

Eric Miller

David S Hoffman

Vincent Floyd Jones

Bill Hansen

Dustin Peterson

Vince Jones

Steven West Wilson

Todd S Parker

Brad Harris

Thomas E Blair

Sanjay Kamtekar

Eric Draper

Jon Barron

Richard Zimmerman

Ricky B Steck

Gordon Ernest Smith

Charles R Jensen

Derek Hullinger

Rick Steck

Sterling W Cornaby

Brian Barnum

Tyler Washburn

David Reynolds

Roland Creed

A planar filamentcan include multiple materials to increase electron emission in desired directions and to suppress electron emission in undesired directions. The filamentcan include a core-material CM between a top-material TM and a bottom-material BM. The top-material TM can have a lowest work function WF; the bottom-material BM can have a highest work function WF; and the core-material CM can have an intermediate work function WF(WF<WF<WF). A width Wof the filamentat a top-sidecan be greater than its width Wat a bottom-side(W>W). This shape makes it easier to coat the edgeswith the bottom-material BM, because the edgestilt toward and partially face the sputter target. This shape also helps direct more electrons to a center of the target, and reduce electron emission in undesired directions.

Planar filament with directed electron beam

A planar filamentcan include multiple materials to increase electron emission in desired directions and to suppress electron emission in undesired directions. The filamentcan include a core-material CM between a top-material TM and a bottom-material BM. The top-material TM can have a lowest work function WF; the bottom-material BM can have a highest work function WF; and the core-material CM can have an intermediate work function WF(WF&#x3c;WF&#x3c;WF). A width Wof the filamentat a top-sidecan be greater than its width Wat a bottom-side(W&#x3e;W). This shape makes it easier to coat the edgeswith the bottom-material BM, because the edgestilt toward and partially face the sputter target. This shape also helps direct more electrons to a center of the target, and reduce electron emission in undesired directions.

X-ray transparent insulation can be sandwiched between an x-ray window and a ground plate. The x-ray transparent insulation can include aluminum nitride, boron nitride, or polyetherimide. The x-ray transparent insulation can include a curved side. The x-ray transparent insulation can be transparent to x-rays and resistant to x-ray damage, and can have high thermal conductivity. An x-ray window can have high thermal conductivity, high electrical conductivity, high melting point, low cost, and matched coefficient of thermal conductivity with the anode. The x-ray window can be made of tungsten. For consistent x-ray spot size and location, a focusing plate and a filament can be attached to a cathode with an open channel of the focusing plate aligned with a longitudinal dimension of the filament. Tabs of the focusing plate bordering the open channel can be bent to align with a location of the filament.

X-ray tube insulation, window, and focusing plate

A shield around an x-ray tube, a voltage multiplier, or both can improve the manufacturing process by allowing testing earlier in the process and by providing a holder for liquid potting material. The shield can also improve voltage standoff. A shielded x-ray tube can be electrically coupled to a shielded power supply.

X-ray source voltage shield

In order to reduce the amount of electrical insulation needed for voltage isolation of large voltages generated by a voltage multiplier, the voltage multiplier can be shaped to smooth out electric field gradients. The voltage multiplier can comprise multiple sections, each section located in a different plane. The voltage multiplier can comprise a negative voltage multiplier and a positive voltage multiplier, each inclined at different angles with respect to each other. The voltage multiplier can include a curved shape.

Non-planar voltage multiplier

An x-ray source can have a reduced voltage gradient and a consistent voltage gradient, thus allowing less insulation, reduced arcing failure, or both. The x-ray source can comprise a bipolar voltage multiplier and an x-ray tube. The bipolar voltage multiplier can include a negative voltage multiplier and a positive voltage multiplier. An axis extending from an input voltage of the negative voltage multiplier to a negative output bias voltage defines a negative axis. An axis extending from an input voltage of the positive voltage multiplier to a positive output bias voltage defines a positive axis. An angle Abetween the negative axis and the positive axis can be selected for optimal voltage gradient.

Bipolar voltage multiplier with reduced voltage gradient

An x-ray source can include a housing with material with an atomic number of &#x2265;42 and a thermal conductivity of &#x2265;3 W/(m*K) to assist in removing heat from the x-ray source and to block x-rays emitted in undesirable directions. An x-ray source can include a shell that is electrically conductive and that encloses at least part of a voltage multiplier without enclosing a control circuit to minimize or eliminate electromagnetic interference in the control circuitry caused by the voltage multiplier. An x-ray source can include a negative voltage multiplier, a positive voltage multiplier, and a ground plane between the negative voltage multiplier and the positive voltage multiplier. The ground plane can minimize or eliminate electromagnetic interference between the negative voltage multiplier and the positive voltage multiplier. An air-filled channel, associated with the ground plane, can reduce weight of the x-ray source.

High voltage power supply casing

Electron beam spot characteristics can be tuned in each x-ray tube by moving a focusing-ring along a longitudinal-axis of the x-ray tube. The focusing-ring can then be immovably fastened to the x-ray tube. An x-ray source can include an x-ray tube and a focusing-ring. The focusing-ring can at least partially encircle an electron-emitter, a cathode, an evacuated-enclosure, or combinations thereof. The focusing-ring can be located outside of a vacuum of the evacuated enclosure. The focusing-ring can adjust an electron-beam spot on a target material of the x-ray tube when moved along a longitudinal-axis extending linearly from the electron-emitter to the target material.

Electron-beam spot optimization

An electrostatic dissipation devicecan comprise an elongated enclosurewith a longitudinal axis. An x-ray sourcecan be oriented to emit x-raysinside of and along the longitudinal axis. A fluid-flow devicecan be oriented to cause fluid to flow across the x-ray sourcethen inside of and along the longitudinal axis, the fluid being ionized by the x-rays, forming ionized fluid, then out of the elongated enclosure through outlet opening(s). The arrangement of the x-ray sourceand the fluid-flow devicecan allow (1) fluid from the fluid-flow deviceto cool the x-ray source, and (2) ion generation along the length of the elongated enclosure

Flowing-fluid X-ray induced ionic electrostatic dissipation

X-ray source with non-planar voltage multiplier

A transmission-target x-ray tube can include an x-ray window mounted on a window-housing. The window-housing can be made of a high density material (e.g. &#x2265;12 g/cm) with a high atomic number (e.g. &#x2265;45), and can include an aperture with an increasing-inner-diameter region, with a smaller diameter closer to the electron-emitter and a larger diameter closer to the window-mount, for blocking x-rays and electrons. An example angle in the increasing-inner-diameter region is between 15 degrees and 35 degrees. The x-ray tube can further comprise a window-cap. The x-ray window can be sandwiched between the window-housing and the window-cap. The window-cap can be made of a high density material (e.g. &#x2265;12 g/cm) with a high atomic number (e.g. &#x2265;45) for blocking x-rays in undesirable directions, and can include an aperture for allowing x-rays to transmit in desirable directions.

Shielded, transmission-target, x-ray tube

An x-ray tube can include an electron-emitter, which can include a tube-shape with a minimum inside diameter of at least 0.5 millimeters. The electron-emitter can provide field-emission of electrons, and thus can avoid the electrical power required for heating, and can avoid degradation due to high temperature of, a thermionic-emission electron-emitter. This type of electron-emitter, with a tube-shape, can have a relatively large electron-emission region, allowing high electrical current without excessive current density.

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Provo, UT, United States of America

Eric Miller