WO2017204850A1 - Sources de rayons x divergents utilisant une accumulation linéaire - Google Patents

Sources de rayons x divergents utilisant une accumulation linéaire Download PDF

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Publication number
WO2017204850A1
WO2017204850A1 PCT/US2016/063884 US2016063884W WO2017204850A1 WO 2017204850 A1 WO2017204850 A1 WO 2017204850A1 US 2016063884 W US2016063884 W US 2016063884W WO 2017204850 A1 WO2017204850 A1 WO 2017204850A1
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Prior art keywords
ray
ray generating
target
volume
ray source
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Ceased
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English (en)
Inventor
Sylvia Jia Yun Lewis
Wenbing Yun
Janos KIRZ
Alan Francis Lyon
David Charles Reynolds
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Sigray Inc
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Sigray Inc
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Priority claimed from US15/166,274 external-priority patent/US10269528B2/en
Application filed by Sigray Inc filed Critical Sigray Inc
Publication of WO2017204850A1 publication Critical patent/WO2017204850A1/fr
Anticipated expiration legal-status Critical
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00—X-ray tubes
    • H01J35/02—Details
    • H01J35/04—Electrodes ; Mutual position thereof; Constructional adaptations therefor
    • H01J35/08—Anodes; Anti cathodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00—X-ray tubes
    • H01J35/02—Details
    • H01J35/04—Electrodes ; Mutual position thereof; Constructional adaptations therefor
    • H01J35/08—Anodes; Anti cathodes
    • H01J35/10—Rotary anodes; Arrangements for rotating anodes; Cooling rotary anodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00—X-ray tubes
    • H01J35/02—Details
    • H01J35/04—Electrodes ; Mutual position thereof; Constructional adaptations therefor
    • H01J35/08—Anodes; Anti cathodes
    • H01J35/10—Rotary anodes; Arrangements for rotating anodes; Cooling rotary anodes
    • H01J35/101—Arrangements for rotating anodes, e.g. supporting means, means for greasing, means for sealing the axle or means for shielding or protecting the driving
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2235/00—X-ray tubes
    • H01J2235/08—Targets (anodes) and X-ray converters
    • H01J2235/081—Target material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2235/00—X-ray tubes
    • H01J2235/08—Targets (anodes) and X-ray converters
    • H01J2235/086—Target geometry
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00—X-ray tubes
    • H01J35/02—Details
    • H01J35/16—Vessels; Containers; Shields associated therewith
    • H01J35/18—Windows

Definitions

  • the embodiments of the invention disclosed herein relate to high-brightness sources of x-rays. Such high brightness sources may be useful for a variety of applications in which x-rays are employed, including manufacturing inspection, metrology, crystal lography, spectroscopy, structure and composition analysis and medical imaging and diagnostic systems.
  • X-ray sources have been used for over a century.
  • One common x-ray source design is the reflection x-ray source 80, an example of which illustrated in FIG. 1 .
  • the source comprises a vacuum environment (typically 10 "6 torr or better) commonly maintained by a sealed vacuum tube 20 or active pumping, and is manufactured with sealed electrical leads
  • the source 80 will typically comprise mounts 30 which secure the vacuum tube 20 in a housing 50, and the housing 50 may additional ly comprise shielding material, such as lead, to prevent x-rays from being radiated by the source 80 in unwanted directions.
  • an emitter 1 1 connected through the lead 21 to the high voltage source 1 0 serves as a cathode and generates a beam of electrons 1 1 1 .
  • a target 1 00 supported by a target substrate 1 1 0 is electrically connected to the opposite high voltage lead
  • the electrons 1 1 1 accelerate towards the target 1 00 and collide with it at high energy, with the energy of the electrons determined by the magnitude of the accelerating voltage.
  • the col lision of the electrons 1 1 1 into the target 1 00 induces several effects, including the generation of x-rays 888, some of which exit the vacuum tube 20 through a window 40 or aperture.
  • the target 100 and substrate 1 1 0 may be integrated or comprise a solid block of the same material, such as copper (Cu).
  • Electron optics electrostatic or electromagnetic lenses
  • electron sources comprising multiple emitters may be provided to provide a larger, distributed source of electrons.
  • the electrons collide with a target 1 00 can interact in several ways. These are illustrated in FIG. 2.
  • the penetration depth is much larger than for a material with greater density, such as most elements used for x-ray generation.
  • electron energy may simply be converted into heat. Some absorbed energy may excite the generation of secondary electrons, typically detected from a region 22 1 located near the surface, while some electrons may also be backscatlered, which, due to their higher energy, can be detected from a somewhat larger region 23 1 .
  • x-rays 888 are generated and radiated outward in all directions.
  • a typical x-ray spectrum for radiation from the collision of 1 00 keV electrons with a tungsten target is il lustrated in FIG. 3.
  • the broad spectrum x-ray radiation 388 commonly cal led “bremsstrahlung”, arises from electrons that were diverted from their initial trajectory.
  • These continuum x-rays 388 are generated throughout the interaction volume, shown in FIG. 2 as the largest shaded portion 288 of the interaction volume 200. As was shown in FIG.
  • the x-ray source 80 wi ll typically have a window 40, which may additionally comprise a filter, such as a sheet or layer of aluminum, that attenuates the low energy x-rays, producing the modified energy spectrum 488 shown in FIG. 3.
  • Characteristic x-rays, shown in FIG. 3 and indicated by 988, are primarily generated in a traction of the electron penetration depth, shown as the second largest shaded portion 248 of the interaction volume 200.
  • the relative depth is influenced in part by the energy of the electrons 1 1 1 , which typically falls off with increasing depth.
  • the actual dimensions of this interaction volume 200 may vary, depending on the energy and angle of incidence of the electrons, the surface topography and other properties (including local charge density), and the density and atom ic composition of the target material .
  • x-rays may be radiated isotropically, as was illustrated in FIG. 2, only the x-ray radiation 888 within a small solid angle produced in the direction of a window in the source will be useful .
  • X-ray brightness also called “brilliance” by some
  • X-ray brightness can be increased by adjusting the geometric factors to maximize the collected x-rays.
  • the surface of a target 1 00 in a reflection x- ray source is generally mounted at an angle ⁇ (as was also shown in FIG. 1 ).
  • radiation at 0° occurs parallel to the surface of a solid metal target for conventional sources, and since the x-rays must propagate along a long length of the target material before emerging, most of the produced x-rays will be attenuated (reabsorbed) by the target material, reducing brightness.
  • a source with take-off angle of around 6° to 1 5° (depending on the source configuration, target material, and electron energy) is conventionally used.
  • Another way to increase the brightness of the x-ray source is to use a target material with a higher atom ic number Z, as efficiency of x-ray production for bremsstrahlung radiation scales with increasingly higher Z.
  • the x-ray radiating material should ideally have good thermal properties, such as a high melting point and high thermal conductivity, in order to allow h igher electron power loading on the source to increase x-ray production.
  • Table 1 lists several materials that are commonly used for x-ray targets, several additional potential target materials (notably useful for specific characteristic lines of interest), and some materials that may be used as substrates for target materials. Melting points, and thermal and electrical conductivities are presented for values near 300°K (27°C). Most values are taken from the CRC Handbook of Chemistry and Physics, 90 lh ed. [CRC Press, Boca Raton, FL, 2009]. Other values are taken from various references.
  • FIG. 5A a cross-section is shown for a rotating anode x-ray source 580 comprising a target anode 500.
  • the target anode 500 is connected by a shaft 530 to a rotor 520 supported by conducting bearings 524 that connect, through its mount 522, to the lead 22 and the positive terminal of the high voltage supply 1 0.
  • the rotation of the rotor 520, shaft 530 and anode 500, all within the vacuum chamber 20, is typical ly driven inductively by stator windings 525 mounted outside the vacuum.
  • FIG. 5B A top view of the target anode 500 is shown in more detail in FIG. 5B.
  • the edge 51 0 of the rotating target anode 500 may be beveled at an angle, and the emitter 1 1 of the electron beam 51 1 directs the electron beam onto the beveled edge 5 1 0 of the target anode 500, generating x-rays 888 at an electron beam spot 501 .
  • the electron beam spot 501 generates x-rays
  • the irradiated spot in the target heats up.
  • the target anode 500 rotates, the heated spot moves away from the beam spot 501 , and the electron beam 51 1 now irradiates a cooler portion of the target anode 500.
  • the hot spot has the time of one rotation to cool before becoming heated again when it again passes through the beam spot 501 .
  • x-rays appear to be generated from a fixed single spot, while the total area of the target i l lum inated by the electron beam is substantially larger than the electron beam spot, effectively spreading the electron energy deposition over a larger area (and volume).
  • Another approach to m itigating heat is to use a target with a thin layer of target x-ray generating material deposited onto a substrate with high heat conduction.
  • the target material itself need not be thicker than a few m icrons, and can be deposited onto a substrate, such as diamond, sapphire or graphite that conducts the heat away quickly.
  • a substrate such as diamond, sapphire or graphite that conducts the heat away quickly.
  • the substrate may also comprise channels for a coolant, that remove heat from the substrate [see, for example, Paul E. Larson, US Patent 5,602,899].
  • Water-cooled anodes are used for a variety of x-ray sources, including rotating anode x-ray sources.
  • the substrate may in turn be mounted to a heat sink comprising copper or some other material chosen for its thermally conducting properties.
  • the heat sink may also comprise channels for a coolant [see, for example, Edward J. Morton, US Patent 8,094,784].
  • thermoelectric coolers or cryogenic systems have been used to provide further cooling to an x-ray target mounted onto a heat sink.
  • Th is disclosure presents x-ray sources that have the potential of being up to several orders of magn itude brighter than existing commercial x-ray technologies.
  • the higher brightness is achieved in part through the use of novel configurations for x-ray targets used in generating x-rays from electron beam bombardment with specific design rules for the electron beam footprint and electron beam energy.
  • the x-ray target configurations may comprise a number of m icrostructures of one or more selected x-ray generating materials fabricated in close thermal contact with (such as embedded in or buried in) a substrate with high thermal conductivity, such that the heat is more efficiently drawn out of the x-ray generating material. This in turn allows bombardment of the x-ray generating material with higher electron power density, which leads to greater x-ray brightness.
  • a significant advantage to some embodiments is that the orientation of the microstructures allows the use of a take off angle at or near to zero degrees allowing the accumulation of x-rays from several microstructures for greater x-ray brightness.
  • Some embodiments of the invention comprise an additional cooling system to transport the heat away from the anode or anodes. Some embodiments of the invention additionally comprise rotating the anode or anodes comprising targets with microstructured patterns in order to further dissipate heat and increase the accumulated x-ray brightness.
  • FIG. 1 illustrates a schematic cross-section diagram of a standard prior art reflection x-ray source.
  • FIG. 2 illustrates a cross-section diagram the interaction of electrons with a surface of a material in a prior art x-ray source.
  • FIG. 3 illustrates the typical x-ray radiation spectrum for a tungsten target.
  • FIG. 4A illustrates x-ray radiation from a prior art target for a target at a ti lt angle of 60 degrees.
  • FIG. 4B illustrates x-ray radiation from a prior art target for a target at a tilt angle of 45 degrees.
  • FIG. 4C il lustrates x-ray radiation from a prior art target for a target at a tilt angle of 30 degrees.
  • FIG. 5A illustrates a schematic cross-section view of a prior art rotating anode x-ray source.
  • FIG. 5B illustrates a top view of the anode for the rotating anode system of
  • FIG. 5A is a diagrammatic representation of FIG. 5A.
  • FIG. 6 i llustrates a schematic cross-section view of an embodiment of an x-ray system according to the invention.
  • FIG. 7 illustrates a perspective view of a target comprising a grid of embedded rectangular target microstructures on a larger substrate that may be used in some embodiments of the invention.
  • FIG. 8 illustrates a cross-section view of electrons entering a target comprising target microstructures on a larger substrate that may be used in some embodiments of the invention.
  • FIG. 9 illustrates a cross-section view of some of the x-rays radiated by the target of
  • FIG. 10 illustrates a perspective view of a target comprising a multiple rectangular microstructures arranged in a linear array on a substrate with a recessed region that may be used in some embodiments of the invention.
  • FIG. 1 1 A illustrates a perspective view of a target comprising a grid of embedded rectangular target microstructures that may be used in some embodiments of the invention.
  • FIG. 1 I B illustrates a top view of the target of FIG. 1 1 A.
  • FIG. 1 1 C illustrates a side/cross-section view of the target of FIGs. 1 1 A and 1 I B.
  • FIG. 12 illustrates a cross-section view of a portion of the target of FIGs. 1 1 A—
  • FIG. 13 illustrates a cross-section view of a target as shown in of FIG. 12 having an additional overcoat and a cooling channel. >
  • FIG. 14 illustrates a collection of x-ray emitters arranged in a linear array to
  • FIG. 1 5 illustrates a plot of the 1 /e attenuation length for several materials for x-rays having energies ranging from 1 keV to 1 ,000 keV.
  • FIG. 1 6 illustrates a schematic cross-section view of an embodiment of an x-ray system according to the invention comprising multiple electron emitters.
  • FIG. 1 7A illustrates a schematic cross-section view of an embodiment of the
  • FIG. 1 7B illustrates a schematic perspective view of the rotating anode of the embodiment of FIG. 1 7A.
  • FIG. 1 7C illustrates a cross-section view of the rotating anode of the embodiment of
  • FIG. 17A is a diagrammatic representation of FIG. 17A.
  • FIG. 1 8 illustrates a schematic perspective view of a portion of an embodiment of the invention comprising a line pattern of x-ray generating structures on a rotating anode.
  • FIG. 19A illustrates a cross-section view of the x-ray generating portion of a source according to an embodiment of the invention.
  • FIG. 1 9B illustrates a perspective view of the x-ray generating portion of the source illustrated in FIG. 19A .
  • FIG. 1 9C i l lustrates detailed cross-section view of the x-ray generating portion of the source illustrated in FIG. 19A.
  • FIG. 20A illustrates a top-down view of the x-ray generating portion of a target used in the embodiment illustrated in FIGs. 1 9A - 19C.
  • FIG. 20B illustrates an end view of the x-ray generating portion of a target used in the embodiment illustrated in FIGs. 19A - 19C.
  • FIG. 20C illustrates a cross-section side view of the x-ray generating portion of a target used in the embodiment illustrated in FIGs. 19A - 19C.
  • FIG. 21 A illustrates a top-down view of the x-ray generating portion of a target having non-uniform x-ray generating structures.
  • FIG. 21 B illustrates an end view of the x-ray generating portion of the target of FIG.
  • FIG. 21 C illustrates a cross-section side view of the x-ray generating portion of the target of FIG. 21 A.
  • FIG. 22A illustrates a top-down view of the x-ray generating portion of the target used in the embodiment illustrated in FIGs. 1 9A - 19C under electron
  • FIG. 22B illustrates an end view of the x-ray generating portion of a target used in the embodiment illustrated in FIGs. 19A - 1 9C under electron bombardment.
  • FIG. 22C illustrates a cross-section side view of the x-ray generating portion of a target used in the embodiment illustrated in FIGs. 1 9A - 1 9C under electron bombardment.
  • FIG. 23 illustrates a cross-section side view of the x-ray generating portion of a target comprising a powder of x-ray generating material.
  • FIG. 24A illustrates a top-down view of the x-ray generating portion of a target comprising structures of x-ray generating material arranged along the length dimension.
  • FIG. 24B illustrates an end view of the x-ray generating portion of the target of
  • FIG. 24A is a diagrammatic representation of FIG. 24A.
  • FIG. 24C illustrates a cross-section side view of the x-ray generating portion of the target of FIG. 24A.
  • FIG. 25 illustrates a cross-section view of the x-ray generating portion of a source according to the invention paired with an external x-ray optical element.
  • FIG. 26 illustrates a cross-section view of a rotating anode according to the
  • FIG. 27 illustrates a cross-section view of a rotating anode according to the
  • FIG. 6 illustrates an embodiment of a reflective x-ray system 80-A according to the invention.
  • the source comprises a vacuum environment (typically 10 "6 ton * or better) commonly maintained by a sealed vacuum chamber 20 or active pumping, and manufactured with sealed electrical leads 21 and 22.
  • the source 80-A will typically comprise mounts 30, and the housing 50 may additionally comprise shielding material, such as lead, to prevent x-rays from being radiated by the source 80-A in unwanted directions.
  • an emitter 1 1 connected through the lead 21 to the negative term inal of a high voltage source 1 0 serves as a cathode and generates a beam of electrons 1 1 1 .
  • Any number of prior art techniques for electron beam generation may be used for the embodiments of the invention disclosed herein. Additional known techniques used for electron beam generation include heating for thermionic emission, Schottky emission (a combination of heating and field emission), or emitters comprising nanostructures such as carbon nanotubes). [For more on electron em ission options for electron beam generation, see Shigehiko Yamamoto, "Fundamental physics of vacuum electron sources", Reports on Progress in Physics vol. 69, pp. 1 8 1 -232 (2006)] .
  • a target 1 1 00 comprising a target substrate 1 000 and regions 700 of x-ray generating material is electrical ly connected to the opposite h igh voltage lead 22 and target support 32, thus serving as an anode.
  • the electrons 1 1 1 accelerate towards the target 1 1 00 and collide with it at high energy.
  • the col l ision of the electrons 1 1 1 into the target 1 1 00 induces several effects, including the generation of x-rays, some of which exit the vacuum tube 20 and are transmitted through at least one window 40 and/or an aperture 840 in a screen 84.
  • an electron beam control mechanism 70 such as an electrostatic lens system or other system of electron optics that is controlled and coordinated with the electron dose and voltage provided by the em itter 1 I by a controller 1 0- 1 through a lead 27.
  • the electron beam 1 1 1 may therefore be scanned, focused, de-focused, or otherwise directed onto the target 1 1 00.
  • the alignment of the microstructures 700 may be arranged such that the bombardment of several of the microstructures 700 by the electron beam or beams 1 1 1 will excite radiation in a direction orthogonal to the surface normal of the target such that the intensity in the direction of view will add or accumulate in that direction.
  • the direction may also be selected by means of an aperture 840 in a screen 84 for the system to form the directional beam 888 that exits the system through a window 40.
  • the aperture 840 may be positioned outside the vacuum chamber, or, more commonly, the window 40 itself may serve as the aperture 840. In some embodiments, the aperture may be inside the vacuum chamber.
  • Targets such as those to be used in x-ray sources according to the invention disclosed herein have been described in detail in the co-pending US Patent Application entitled STRUCTURED TARGETS FOR X-RAY GENERATION (US Patent Appl ication 14/465,8 1 6, filed Aug. 2 1 , 2014), which is hereby incorporated by reference in its entirety, along with the provisional Applications to which this co-pending Application claims benefit. Any of the target designs and configurations disclosed in the above referenced co-pending Application may be considered for use as a component in any or all of the x-ray sources disclosed herein .
  • FIG. 7 illustrates a target 1 100 as may be used in some embodiments of the invention.
  • a substrate 1 000 has a region 1 001 that contains an array of microstructures 700 comprising x-ray generating material (typically a metallic material) arranged in a regular array of right rectangular prisms. Electrons 1 1 1 bombard the target and generate x-rays in the m icrostructures 700.
  • the material in the substrate 1000 is selected such that it has relatively low energy deposition rate for electrons in comparison to the x-ray generating m icrostructure material (typically by selecting a low Z material for the substrate ).
  • the material of the substrate 1 000 may also be chosen to have a high thermal conductivity, typical ly larger than 1 00 W/(m °C).
  • the microstructures are typically embedded within the substrate, i.e. if the m icrostructures are shaped as rectangular prisms, it is preferred that at least five of the six sides are in close thermal contact with the substrate 1 000, so that heat generated in the m icrostructures 700 is effectively conducted away into the substrate 1 000.
  • targets used in other embodiments may have fewer direct contact surfaces.
  • the term "embedded" is used in this disclosure, at least half of the surface area of the microstructure will be in close thermal contact with the substrate.
  • a target 1 100 according to the invention may be inserted as the target in a reflecting x-ray source geometry (e.g. FIG. 1 ), or adapted for use as the target used in the rotating anode x-ray source of FIGs. 5 A and 5B.
  • microstructure in this Application will only be used for structures comprising materials selected for their x-ray generating properties. It should also be noted that, although the word “microstructure” is used, x-ray generating structures with dimensions smaller than the micrometer scale, or even as small as nano-scale dimensions (i.e. greater than 10 nm) may also be described by the word “m icrostructures” as used herein.
  • the microstructures may be placed in any number of relative positions throughout the substrate 1 000.
  • the target 1 1 00 comprises a recessed shelf 1002. This allows the region 1 001 comprising an array of m icrostructures 700 to be positioned flush with, or close to, a recessed edge 1 003 of the substrate, and produce x-rays at or near zero angle without being reabsorbed by the substrate 1 000, while providing a more symmetric heat sink for the heat generated when exposed to electrons 1 1 1 .
  • Some other embodiments may preferably have the microstructures placed near the edge of the substrate to minimize self-absorption.
  • FIG. 8 illustrates the relative interaction between a beam of electrons 1 1 1 and a target comprising a substrate 1 000 and m icrostructures 700 of x-ray generating material. Three electron interaction volumes are illustrated, with two representing electrons bombarding the two shown m icrostructures 700, and one representing electrons interacting with the substrate.
  • the depth of penetration can be estimated by Potts' Law. Using this formula, Table II illustrates some of the estimated penetration depths for some common x-ray target materials.
  • Table II Estimates of penetration depth for 60 keV electrons into some materials.
  • the majority of characteristic Cu K x-rays are generated within depth D M -
  • the electron interactions below that depth are less efficient at generating characteristic Cu K- line x-rays but will contribute to heat generation. It is therefore preferable in some embodiments to set a maximum thickness for the m icrostructures in the target in order to optimize local thermal gradients.
  • Some embodiments of the invention limit the depth of the microstructured x-ray generating material in the target to between one third and two thirds of the electron penetration depth of the x-ray generating material at the incident electron energy, while others may similarly limit based on the electron penetration depth with respect to the substrate material.
  • selecting the depth D M to be less than the electron penetration depth is also generally preferred for efficient generation of bremsstrahlung radiation.
  • the depth of the x-ray generating material may be selected to be 50% of the electron penetration depth of either the x-ray generating material or the substrate material.
  • the depth D M for the microstructures may be selected related to the "continuous slowing down approximation" (CSDA) range for electrons in the material .
  • Other depths may be specified depending on the x-ray spectrum desired and the properties of the selected x-ray generating material.
  • a particular ratio between the depth and the lateral dimensions (such as width W M and length L M ) of the x-ray generating material may also be specified. For example, if the depth is selected to be a particular dimension D M , then the lateral dimensions W M and/or L M may be selected to be no more than 5XD M , giving a maximum ratio of 5.
  • the lateral dimensions W M and/or L M may be selected to be no more than 2XD M - It should also be noted that the depth D M and lateral dimensions W M and L M (for width and length of the x-ray generating microstructure) may be defined relative to the axis of incident electrons, with respect to the x-ray emission path, and/or with respect to the orientation of the surface normal of the x-ray generating material . For electrons incident at an angle, care must be taken to make sure the appropriate projections for electron penetration depth at an angle are used.
  • FIG. 9 illustrates the relative x-ray generation from the various regions shown in FIG. 8.
  • X-rays 888 comprising characteristic x-rays are generated from the region 248 where electron collisions overlap the microstructures 700 of x-ray generating material, while the regions 1280 and 1 080 where the electrons interact with the substrate generate characteristic x-rays of the substrate element(s).
  • continuum bremsstrahlung radiation x-rays radiated from the region 248 of the m icrostructures 700 of the x-ray generating material may be stronger than the x-rays 1088 and 1288 produced in the regions 1280 and 1 080.
  • FIG. 9 shows x-rays radiated only to the right, this is in anticipation of a window or col lector being placed to the right.
  • FIG. 9 illustrates an arrangement that allows the linear accumulation of characteristic x-rays along the microstructures, and therefore can be used to produce a relatively strong characteristic x-ray beam .
  • lower energy x-rays may be attenuated by the target materials, which will effectively act as an x-ray filter.
  • Other selections of materials and geometric parameters may be chosen (e.g. a non-l inear scheme) if continuum x-rays are desired, (e.g. for near edge or extended fine structure spectroscopy).
  • targets that are arranged in planar configurations have been presented. These are generally easier to implement, since equipment and process recipes for deposition, etch ing and other planar processing steps are wel l known from processing devices for microelectromechanical systems (MEMS) applications using planar diamond, and from processing silicon wafers for the semiconductor industry.
  • MEMS microelectromechanical systems
  • a target with a surface with additional properties in three dimensions (3-D) may be desired.
  • the apparent x-ray source size and area is at minimum (and brightness maximized) when viewed at a zero degree (0°) take-off angle.
  • the distance through which an x-ray beam will be reduced in intensity by 1 /e is called the x-ray attenuation length, designated by and therefore, a configuration in which the generated x-rays pass through as little additional material as possible, with the distance selected to be related to the x-ray attenuation length, may be desired.
  • FIG. 1 An illustration of a portion of a target as may be used in some embodiments of the invention is presented in FIG. 1 0.
  • an x-ray generating region 71 0 with seven m icrostructures 71 1 , 71 2, 713, 714, 71 5, 71 6, 71 7 is configured near a recessed edge 1 003 of the target substrate 1000 by a shelf 1002, similar to the situation illustrated in FIG. 7.
  • the x-ray generating microstructures 71 1 , 712, 71 3, 714, 71 5, 7 1 6, 71 7 are arranged in a linear array of x-ray generating right rectangular prisms embedded in the substrate 1000, and produce x-rays 1 888 when bombarded with electrons 1 1 1 .
  • the surface normal in the region of the m icrostructures 7 1 1 - 71 7 is designated by «, and the orthogonal length and width dimensions are defined to be in the plane perpendicular to the normal of said predetermined surface, while the depth dimension into the target is defined as parallel to the surface normal.
  • the th ickness D M of the m icrostructures 71 1 - 71 7 in the depth direction is selected to be between one third and two thirds of the electron penetration depth of the x-ray generating material at the incident electron energy for optimal thermal performance.
  • the width W M of the m icrostructures 71 1 - 71 7 is selected to obtain a desired source size in the corresponding direction. As illustrated, W M ⁇ Z),w. As discussed previously, W M could also be substantially smaller or larger, depending on the shape and size of the source spot desired.
  • each of the m icrostructures 71 1 - 71 7 is the length of each of the m icrostructures 71 1 - 71 7 .
  • the total length L To1 , of the x- ray generating region 71 0 will common ly be about twice the linear attenuation length ⁇ L for x-rays in the x-ray generating material, but can be selected to be half to more than 4 times that distance.
  • microstructures may be embedded in the substrate (as shown), but in some embodiments may they may also be partially embedded, or in other embodiments placed on top of the substrate.
  • the first target modeled has a uniform coating of copper 300 microns thick as the x-ray material, as is common in commercial x-ray targets. Simulation of bombardment of the copper layer with electrons over an el lipse 1 0 m icrons wide and 66 microns long predicts an increase in the temperature of the copper to over 700 °C.
  • the second target has 22 discrete structures of copper as the x-ray generating material, arranged in a one-dimensional array similar to that illustrated in FIG. 1 0.
  • the m icrostructures of copper are embedded in diamond, and have an axis of orientation perpendicular to the surface normal of the target.
  • the length of each x-ray generating structure along the axis of the array L M is 1 micron, and elements are placed with a separatio P of 2 microns.
  • both targets are modeled as being bombarded with an electron beam that raises the temperature to the operating temperature of -700 °C.
  • the uniform copper target reaches this temperature with an electron exposure of 16 Watts.
  • the copper reaches the operating temperature of -700 °C with an exposure of 65 Watts - a level 4 times higher. Normalizing for the reduced copper volume still gives more than twice the power deposited into the copper regions. Moreover, electron energy deposition rates between the materials is much more substantial in the higher density Cu than in diamond, and is therefore predicted to generate at least twice the number of x-rays. This demonstrates the utility of embedding microstructures of x-ray generating material into a thermally conducting substrate, in spite of a reduction in the total amount of x-ray generating material.
  • FIGs. 1 1 A - 1 1 C illustrate a region 1 001 of a target as may be used in some embodiments of the invention that comprises an array of microstructures 700 in the form of right rectangular prisms comprising x-ray generating material arranged in a two-dimensional regular array.
  • FIG . 1 1 A presents a perspective view of the sixteen microstructures 700 for this target, whi le FIG. 1 1 B i llustrates a top down view of the same region, and
  • FIG. 1 1 C presents a side/cross-section view of the same region.
  • the ratio is essentially 1 .
  • the ratio may be increased to 6.
  • the heat transfer is illustrated with representative arrows in FIG. 12, in which the heat generated in microstructures 700 embedded in a substrate 1000 is conducted out of the microstructures 700 through the bottom and sides (arrows for transfer through the sides out of the plane of the drawing are not shown).
  • the amount of heat transferred per unit time conducted through a material of area A and thickness d increases with the temperature gradient, the thermal conductivity in W/(m °C), and the surface area through which heat is transferred. Embedding the microstructures in a substrate of high thermal conductivity increases all these factors.
  • FIG. 13 illustrates an alternative embodiment in which an overcoat has been added to the surface of the target.
  • This overcoat 725 may be an electrically conducting layer, providing a return path to ground for the electrons bombarding the target.
  • the thin layer of conducting material that is preferably of relatively low atomic number, such as Titanium (Ti) is used.
  • Other conducting materials such as silver (Ag), copper (Cu), gold (Au), tungsten (W), aluminum (Al), beryllium (Be), carbon (C), graphene, or chromium (Cr) may be used to allow electrical conduction from the discrete
  • microstructures 700 to an electrical path 722 that connects to a positive terminal relative to the high voltage supply.
  • overcoats are typically thin films, with thickness on the order of 5 to 50 nm.
  • this overcoat 725 may comprise a material selected for its thermal conductivity.
  • this overcoat 725 may be a layer of diamond, deposited by chemical vapor deposition (CVD). This allows heat to be conducted away from all sides of the microstructure. It may also provide a protective layer, preventing x-ray generating material from subliming away from the target during extended or prolonged use. Such protective overcoats typically have thicknesses on the order of 0.2 to 5 microns. Such a protective overcoat may also be deposited using an additional dopant to provide electrical conductivity as well. In some embodiments, two distinct layers, one to provide electrical conductivity, the other to provide thermal conductivity and/or encapsulation, may be used. In some embodiments, overcoats may comprise beryllium, diamond, polycrystalline diamond, CVD diamond, diamond-like carbon, graphite, silicon, boron nitride, silicon carbide and sapphire.
  • the substrate may additionally comprise a cooling channel 1200, as also illustrated in FIG. 13.
  • Such cooling channels may be a prior art cooling channel using flowing water or some other cooling fluid to conduct heat away from the substrate, or may be fabricated according to a design adapted to best remove heat from the regions near the embedded microstructures 700.
  • microstructures comprising multiple x-ray generating materials, microstructures comprising alloys of x-ray generating materials, microstructures deposited with an anti-diffusion layer or an adhesion layer, microstructures with a thermally conducting overcoat, microstructures with a thermally conducting and electrically conducting overcoat, microstructured buried within a substrate and the like.
  • m icrostructures that may comprise any number of conventional x-ray target materials patterned as features of m icron scale dimensions on or embedded in a thermally conducting substrate, such as diamond or sapphire.
  • the microstructures may alternatively comprise unconventional x-ray target materials, such as tin (Sn), sulfur (S), titanium (Ti), antimony (Sb), etc. that have thus far been limited in their use due to poor thermal properties.
  • 14/465,816 are arrays of m icrostructures that take any number of geometric shapes, such as cubes, rectangular blocks, regular prisms, right rectangular prisms, trapezoidal prisms, spheres, ovoids, barrel shaped objects, cyl inders, triangular prisms, pyram ids, tetrahedra, or other particularly designed shapes, including those with surface textures or structures that enhance surface area, to best generate x-rays of high brightness and that also efficiently disperse heat.
  • geometric shapes such as cubes, rectangular blocks, regular prisms, right rectangular prisms, trapezoidal prisms, spheres, ovoids, barrel shaped objects, cyl inders, triangular prisms, pyram ids, tetrahedra, or other particularly designed shapes, including those with surface textures or structures that enhance surface area, to best generate x-rays of high brightness and that also efficiently disperse heat.
  • 14/465,81 6 are arrays of microstructures comprising various materials as the x-ray generating materials, including aluminum, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, gallium, zinc, yttrium, zirconium, molybdenum, niobium, ruthenium, rhenium, rhodium, palladium, silver, tin, iridium, tantalum, tungsten, indium, cesium, barium, germanium, gold, platinum, lead and combinations and alloys thereof.
  • various materials as the x-ray generating materials including aluminum, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, gallium, zinc, yttrium, zirconium, molybdenum, niobium, ruthenium, rhenium, rhodium, palladium, silver, tin, iridium, tantalum, tungsten,
  • the embodiments described so far include a variety of x-ray target configurations that comprise a plurality of microstructures comprising x-ray generating material that can be used as targets in x-ray sources to generate x-rays with increased brightness.
  • FIG. 14 illustrates a collection of x-ray sub-sources arranged in a linear array.
  • the long axis of the linear array runs from left to right in the figure, while the short axis would run in and out of the plane of the figure.
  • Several x-ray generating elements 801 , 802, 803, 804 .. . etc. com prising one or more x-ray generating materials are bombarded by beams of electrons 1 1 1 1 , 1 1 12, 1 1 13, 1 1 14, ... etc. at high voltage (anywhere from 1 to 250 keV), and form sub-sources that produce x-rays 81 8, 828, 838, 848, ... etc.
  • this analysis is for a view along the axis down the center of the linear array of sub-sources, where a screen 84 with an aperture 840 has been positioned.
  • the aperture allows the accumulated zero-angle x-rays to emerge from the source, but in practice, an aperture which allows several degrees of x-rays radiated at ⁇ 3° or even at ⁇ 6° to the surface normal may be designed for use in some applications. It is generally preferred that the window be at normal or near normal incidence to the long axis of a linear array, but in some embodiments, a window ti lted to an angle as large as 85° may be useful. [0116] Assum ing the ith sub-source 80/ produces x-rays 8/8 along the axis to the right in FIG. 14, the radiation for the right-most sub-source as illustrated simply propagates to the right through free space.
  • the x-rays from the other sub-sources are attenuated through absorption, scattering, or other loss mechanisms encountered while passing through whatever material lies between sub-sources, and also by divergence from the propagation axis and by losses encountered by passage through the neighboring sub-source(s) as well.
  • T, and T i,i-l represent a reduction in transmission due to losses, and therefore always have values between 0 and 1 . If N is large, the sum on the right can be approximated by the geometric series
  • Eqn.9 indicates that of the estimated maximum from Eqn. 12, while for 3 elements (a total x-ray generation length of
  • FIG. 1 5 illustrates the 1 /e attenuation length for x-rays having energies ranging from 1 keV to 1 000 keV for three x-ray generating materials: molybdenum (Mo), copper (Cu)nch tungsten (W); and from 1 0 keV to 1000 keV for three substrate materials:
  • the 1 /e attenuation length ⁇ L for a material is related to the transmission factors above for a length L by
  • a larger ⁇ L . means a larger T, .
  • the beam or beams of electrons 1 1 1 1 or 1 1 1 1 1 , 1 1 12, 1 1 13, etc. bombarding the x-ray generating elements 801 , 802, 803... etc. may be shaped and directed using one or more electron control mechanisms 70 such as electron optics, electrostatic lenses or magnetic focusing elements.
  • electron control mechanisms 70 such as electron optics, electrostatic lenses or magnetic focusing elements.
  • electrostatic lenses are placed within the vacuum environment of the x-ray source, while the magnetic focusing elements can be placed outside the vacuum.
  • the area of electron exposure can be adjusted so that the electron beam or beams primarily bombard the x-ray generating elements and do not bombard the regions in between the elements.
  • a source having multiple electron beams that are used to bombard distinct x-ray generating elements independently may also be configured to allow a different accelerating voltage to be used with the different electron beam sources.
  • Such a source 80-B is illustrated in FIG. 1 6.
  • the previous high voltage source 10 is again connected through a lead 21 -A to an electron em itter 1 1 -A that emits electrons 1 1 1 -A towards a target 1 1 00-B.
  • two additional “boosters" for voltage 10- B and 1 0-C are also provided, and these higher voltage potentials are connected through leads 21 -B and 21 -C to additional electron emitters 1 1 -B and 1 1 -C that respectively emit electrons 1 1 1 -B and 1 1 1 -C of different energies.
  • the target 1 1 00-B wil l usually be uniform ly set to the ground potential
  • the individual electron beam sources used to target the different x-ray generating elements may be set to different potentials, and electrons of varying energy may therefore be used to bombard the different x-ray generating elements 801 , 802, 803, ... etc.
  • This may offer advantages for x-ray radiation management, in that electrons of different energies may generate different x-ray radiation spectra, depending on the materials used in the individual x-ray generating elements.
  • the heat load generated may also be managed through the use of different electron energies. 3.2. Material Variations.
  • the different x-ray generating elements may comprise different x-ray generating materials, so that the on-axis view presents a diverse spectrum of characteristic x-rays from the different materials.
  • Materials that are relatively transparent to x-rays may be used in the position closest to the output window 840 (e.g. the element 801 furthest to the right in FIG. 14), while those that are more strongly absorbing may be used for elements on the other side of the array, so that they attenuate the other x-ray sub-sources less.
  • the distance between the x-ray generating elements may be varied. For example, a larger space between elements may be used for elements that are expected to generate more heat under electron bombardment, while smaller gaps may be used if less heat is expected.
  • FIGs. 1 7A - 1 7C A system 580-C comprising these features is illustrated in FIGs. 1 7A - 1 7C.
  • many of the elements are the same as in a conventional rotating anode system, as was illustrated in FIG. 5A, but in the embodiment as illustrated, the rotating mechanism has been rotated 90° relative to the electron beam emitter 1 1 -R and the electron beam 5 1 1 -R.
  • the target in the embodiment as illustrated is a rotating cyl inder 5 1 00 mounted on a shaft 530.
  • a set 5710 of rings of x-ray generating material 571 1 - 57 1 7 have been embedded into a layer of substrate material 5000, with a gap between each ring.
  • the "length" (parallel to the shaft axis in this i llustration, and perpendicular to the local normal n in the region under bombardment) of each ring may be comparable to the length discussed for the set of microstructures illustrated in FIG. 1 0 (i.e. micron-scale), and the spacing may be comparable to (also micron-scale).
  • the “width”, however, is the circumference, as the rings 571 0 circle the entire cylinder 5 1 00.
  • This substrate material 5000 may in turn be attached or mounted on a core support 5050 attached to the rotating shaft 530.
  • the core support may comprise any number of materials, but a core of an inexpensive material with high thermal conductivity, such as copper, may be preferred.
  • a solid core/substrate combination that comprises a single material may also be used in some embodiments.
  • the substrate 5000 may be deposited using a CVD process, or pre-fabricated and attached to the core support 5050.
  • FIGs. 1 7A - 1 7C are provided only to illustrate the functioning of an embodiment of the invention, and that the relative sizes, dimensions, and proportions of the rotating shaft 530, core support 5050, substrate 5000, and rings of x-ray generating material 571 1 - 57 1 7 should not be inferred from these drawings.
  • the use of only seven rings in the illustration is also not meant to be lim iting, as embodiments with any number of x-ray generating structures may be used.
  • the substrate thickness may range from a few m icrons to 200 m icrons, while the core may typically have a diameter of 2 cm to 20 cm .
  • a cylinder in which the core and substrate are the same material may also be used in some embodiments.
  • Various overcoats for electrical conduction and/or protection, as discussed for planar targets and illustrated in FIG. 1 3, may also be applied to embodiments having a rotating anode.
  • FIG. 1 8 illustrates a target cylinder 51 01 for a rotating anode comprising a set of parallel lines 5720 that have an orientation perpendicular to that used for the rings of FIG. 1 7B.
  • the transmission of x-rays T for the substrate be near 1 .
  • a substrate material of length L and linear absorption coefficient ⁇ s For a substrate material of length L and linear absorption coefficient ⁇ s ,
  • ⁇ L is the length at which the x-ray intensity has dropped by a factor of 1 /e.
  • the embodiments of the invention disclosed in this Application can be especially suitable for making a high brightness x-ray source for use at one or more predetermined low take-off angles.
  • the arrangement of discrete structures of x-ray generating material can be arranged to increase the x-ray radiation into a predetermined cone of angles around a predetermined take-off angle.
  • Such a predetermined cone can be matched to the acceptance angles of a defined x-ray optical system to increase or maximize the useful x-ray intensity that may be delivered to a sample in applications such as XRD, XRF, SAXS, TXRF, especially, with microbeams, such as microXRD, microXRF, microSAXS, microXRD, etc.
  • Examples of such an x-ray optical system is one having a monocapillary x-ray optical element with a defined inner reflective surface, such as a paraboloidal collimator or a dual paraboloidal or ellipsoidal focusing surface.
  • the arrangement of discrete structures of x-ray generating material can be arranged to increase the x-ray radiation into a predetermined fan of angles around a predeterm ined take-off angle.
  • Such a distribution of x-rays may be matched to other x-ray optical elements designed to produce x-ray beams with a line profile or collimated to form a parallel beam instead of a focused spot.
  • the design of the layout of the x-ray generating elements in the target can be optim ized to increase the x-rays radiated in specific directions using two factors.
  • One is the management of the thermal load, so that heat is efficiently transported away from the x-ray generating elements. With effective thermal transfer, the x-ray generating elements can be bombarded with an electron beam of even greater power density to produce more x-rays.
  • the second is the distribution of the x-ray generating materials such that the self-absorption of x- rays propagating through the remaining volume of x-ray generating material is reduced and linear accumulation of x-rays is optim ized.
  • FIGs. 19A - 1 9C illustrate an example of a target 1 1 00-T comprising a set
  • the x-ray generating material produces x-rays 2088.
  • the target 1 100-T there is a local surface in the area of the x-ray generating elements that has a surface normal n. This defines an axis for the dimension of depth D into the target for determining the depth of the x-ray generating materials. This axis is also used to measure the electron penetration depth or the electron continuous slowing down approximation depth (CSDA depth).
  • CSDA depth electron continuous slowing down approximation depth
  • a predetermined take-off direction (designated by ray 88-T) for the downstream formation of an x-ray beam.
  • This take-off direction is oriented at an angle ir relative to the local surface, and the projection of this ray onto the local surface (designated by ray 88-S) in the plane that contains both the take-off angle and the surface normal is a determinant of the dimension of length L for the target.
  • the final dimension of width W is defined as the third spatial dimension orthogonal to both the depth and the length directions.
  • the set of discrete structures of x-ray generating material is in the form of a linear array of x-ray generating microstructures, each of length L M , width and depth D M , the same as was that illustrated in FIG. 1 0.
  • W M D M
  • the width and depth need not be identical.
  • the microstructures are aligned along an axis parallel to the length L dimension, and are separated from each other by a gap so that the total length of the x-ray generating
  • volume comprising 7 microstructures of x-ray generating material
  • predetermined take off angle and the surface normal may or may not be parallel.
  • the coordinates of depth, length and width are defined only by the surface normal and the predetermined take-off angle.
  • a predetermined set of cone angles is defined, centered around the take-off angle ⁇ T .
  • a ray propagating along the innermost portion of the cone makes an angle ⁇ 1 with respect to the take off angle, while a ray propagating along the outermost portion of the cone makes an angle (3 ⁇ 4 with respect to the take off angle.
  • These cone angles are generally quite small (less than 50 mrad), and the takeoff angle is generally between 0° to 6° (0 to 105 mrad).
  • the actual design of the x-ray target may be more easily described using the concept of an "x-ray generating volume", as discussed further below.
  • Th is is the volume of the target from which the substantial majority of the x-rays of a desired energy will be radiated.
  • the "x-ray generating volume" of a target comprising discrete structures of x-ray generating material is the volume of the target that, when bombarded with electrons, generates x-rays of a desired energy.
  • the energy is typically specified as the characteristic x-ray radiation generated by specific transitions in the selected x-ray generating material, although for certain applications, spectral bandwidths of continuum x-rays from the x-ray generating material may also be designated.
  • x-ray generating volume Two “volumes” must be considered to define the "x-ray generating volume”: a “geometric volume” encompassing the x-ray generating material, and the “electron excitation volume” encompassing the region in which electrons deliver enough energy to generate x-rays.
  • the "geometric volume" for the x-ray generating material is defined as the minimum contiguous volume that completely encompasses a given set of discrete structures of x-ray generating material and the gaps between them.
  • the "geometric volume" 7710 is a rectangle surrounding the
  • microstructures of x-ray generating material are microstructures of x-ray generating material.
  • the "geometric volume” may be more complex.
  • a set 271 0 of non-un iform structures of x-ray generating material 271 1 , 2712. . . 271 7 are embedded within a substrate 1000, in which structures are tapered smaller as they approach the edge 1003 of the substrate.
  • the "geometric volume” 771 1 for this case is not a rectangle, but a tapered polyhedron having square ends of different sizes.
  • the "electron excitation volume” is the volume of the target in which electrons deliver enough energy to generate x-rays of a predetermined desired energy.
  • FIG. 22A - 22C illustrate this situation.
  • electron beam 1 1 1 bombards a portion of the same target comprising a set 710 of x-ray generating materials embedded in a substrate 1 000 - the same target layout as was shown in FIGs. 19A - 1 9C, and 20 A— 20C.
  • the extent of the electron beam does not encompass the entire set of structures, but has a beam width of W e less than W M , and a beam length L e which is less than Lr o i and is also not exactly aligned with the edge of the target structures.
  • the overall area of exposure at the surface is therefore the area of the electron beam at the intersection with the surface (the electron beam "footprint"), defined at some threshold value, such as the full-width-at half-maximum (FWHM) value or the 1 /e value relative to the peak intensity.
  • the defined boundary for the footprint wil l be defined at the contour where the electron intensity is at 50% of the maximum electron intensity.
  • the electron beam bombarding the target may have various sizes and shapes, depending on the electron optics selected to direct and shape the electron beam.
  • the electron beam may be approximately circular, elliptical, or rectangular.
  • the accelerating voltage will be selected to be at least twice that needed to produce x-rays of a given energy (e.g. to produce x-rays with an energy of ⁇ 8 keV, the accelerating voltage is preferred to be at least 1 6 keV).
  • the x-ray generating volume may be identical to the "geometric volume" as described above.
  • the depth of the m icrostructured x-ray generating material D M may be significantly deeper than the electron penetration depth into the substrate, which may be estimated using Potts' Law (as discussed above), or deeper than the continuous slowing down approximation (CSDA) range (CSDA values normalized for element density may be computed using the N1ST website physics. nist.gov/PhysRefData/Star/Text/ESTAR. html).
  • the deeper regions of x- ray generating material may be relatively unproductive in generating x-rays, and the x-ray generating volume is preferably defined by the area overlap of the electron footprint upon the sample with the minimal geometric area containing the microstructures and the electron penetration depth of the electrons into the substrate.
  • the electron penetration depth by Potts' Law is estimated to be -5.2 m icrons, while the CSDA depth is ⁇ 10.6 microns.
  • the Potts' Law penetration depth is -1 5.3 microns, while the CSDA depth for the diamond substrate is ⁇ 1 8.9 microns.
  • the depth of the x-ray generating structures D M measured from the target surface may be limited to be less than the penetration depth of the electrons into the x-ray target substrate material. In most cases (due to the typically lower mass density of the x-ray substrate relative to the x-ray generating material), the entire depth of x-ray generating material will be generating x-rays. In some embodiments, the depth of the x-ray generating structures D M measured from the target surface may be some multiple (e.g. l x - 5x) of the penetration depth of the electrons into the x-ray target substrate material.
  • the depth Di> of the electron excitation volume 7770-E in which x-rays are generated will be less than D M , as illustrated in FIGs. 22A - 22C, and the depth Dp wi l l be defined as a predetermined number related to either the electron penetration depth or the CSDA depth.
  • the depth dimension is defined as paral lel to the surface normal, and if the electron beam is incident on the target surface at an angle ⁇ other than 0° (normal incidence), the depth D P of the electron excitation volume must be modified from the normal incidence penetration depth by a factor of cos ⁇ .
  • the depth of the x-ray generating structures D M measured from the target surface may be limited to be less than the penetration depth of the electrons into the x-ray generating material. This may include I X the penetration depth, or in some cases, preferably a fraction of the penetration depth such as 1 /2 or 1 /3 of the penetration depth.
  • the depth Dp of the electron excitation volume will be defined as being equal to half the penetration depth of the target X-ray generating material, since this is the depth o ⁇ 'er which the electrons will generate more characteristic x- rays. (See the discussion of FIG. 2 above for more on the topic of characteristic x-ray generation.
  • the x-ray generating volume will be defined as the volume overlap of the "geometric volume” for the x-ray generating material within the target and the "electron excitation volume” for electrons of a predetermined energy and known penetration depth and CSDA depth for materials of the target.
  • the volume fraction of the x-ray generating volume is defined as the ratio of the volume of the x-ray generating material within the x-ray generating volume to the overall x-ray generating volume.
  • a typical prior art x-ray target with a uniform target of x-ray generating material will have a volume fraction of 1 00%.
  • Targets such those illustrated in FIG. 1 0, with m icron and L m icrons, have a volume fraction of ⁇ 37 %.
  • a general rule for the x-ray sources according to the invention disclosed here is that the volume fraction of the x-ray generating volume be between 1 0 and 70%, with the non-x-ray generating portion being filled with material of a high thermal conductivity.
  • the regions of non-x-ray generating material serve to conduct the heat away from the x-ray generating structures, enabling bombardment with an electron beam of higher power, thereby producing more x-rays.
  • the ideal volume fraction for a target typically depends on the relative thermal properties of the x-ray generating material and the substrate material in the x-ray generating volume. If the target is fabricated by embedding discrete structures of x-ray generating material with moderate thermal properties into a substrate of high thermal conductivity, good thermal transfer is generally achieved. If the thermal transfer between the x-ray generating material and the substrate is poor (for example, in circumstances of when the x-ray generating material has poor thermal properties), a smaller volume fraction may be desired. In general, for the embedded target structures described herein, a volume fraction of 30% - 50% is preferred.
  • the discrete x-ray structures are not manufactured through etching or ordered patterning processes but instead formed using less ordered discrete structures, such as powders of target materials.
  • FIG. 23 illustrates a target fabricated by such a process.
  • a groove 7001 or set of grooves may be formed using standard substrate patterning techniques.
  • the groove 7001 is then filled with particles of a powder of x-ray generating material 7077.
  • the particles 7077 may be of a predeterm ined average size and shape, so that a measured volume of the material may be used to produce a desired volume fraction within the groove.
  • the gaps between particles 7006 can be filled with a coating of material deposited by chem ical vapor deposition (CVD) processes. This provides the thermal dissipation for the heat produced in the x-ray generating target structures.
  • CVD chem ical vapor deposition
  • the x-ray generating material When bombarded by electrons 1 1 1 , the x-ray generating material will produce x-rays 8088.
  • the x-ray generating volume 7070 will be the overlap of the groove (defining the geometric volume) and the projection of the footprint of the electron beam at the surface.
  • the powders may be pressed into an intact ductile substrate material.
  • additional overcoats as described for more regular structures and illustrated in FIG. 13 may be used for targets fabricated using powders as well.
  • the substrate is preferably a material with high thermal conductivity, such as diamond or beryllium, and the fil ling material is a matching material (e.g. diamond) deposited by CVD.
  • a material with high thermal conductivity such as diamond or beryllium
  • the fil ling material is a matching material (e.g. diamond) deposited by CVD.
  • the x-ray source target substrate material is preferred to have superior thermal properties, particularly its thermal conductivity, in respect to the x-ray generating material. Moreover, it is preferred that substrate materials of the target limit the self- absorption of x-rays produced in the target along the low take-off angle. In many
  • the thermal conductivity is severely reduced in very thin samples of the material. There may therefore be a minimum thickness required for the space between structures of x-ray generating material.
  • ⁇ L ⁇ is be defined to be the 1 /e attenuation length for x-rays of that energy in the same material. Values for this number have been illustrated in FIG, 1 5, and numerical values are shown in Table III below for a few commonly used x-ray generating materials.
  • the x-ray energies are taken from the NIST website physics.nist.gov/PhysRefData/XrayTrans/Html/search.html and the attenuation lengths are calculated using the same sources as were used for the data in FIG. 1 5.
  • the propagation path through x-ray generating material for any given x-ray path should be less than 4 x
  • a design rule that the entire length of the groove L / perhaps, be less than 4 x ⁇ may be followed.
  • a design rule that Lr 0 i be less than (4 x ⁇ divided by the volume fraction may be followed.
  • a design rule limiting the length of the sum of segments in which a predetermined ray overlaps the x-ray generating material may be set.
  • the designated ray is the ray 88-T corresponding to the take-off angle at ⁇ , shown relative to a ray 88-M running through the m idpoint of the x-ray generating volume.
  • the path of this ray 88-T through the x-ray generating volume 771 0-E has several segments of overlap 71 1 -S, 712-S, 71 7-S corresponding to the overlap with the slabs 71 1 , 712, .... 71 7 of x-ray generating material.
  • a general design rule can be stated that, for any ray parallel to the take-off angle ray, the sum of the segments of overlap with the x-ray generating material within the x-ray generating volume must be smaller than 4 x ⁇ ⁇ . In some embodiments, this sum of the segments of overlap with the x-ray generating material within the x-ray generating volume must be smaller than 2 x ⁇ L ⁇ .
  • FIG. 1 9C uses the ray of the take-off angle as a design rule, other embodiments may instead have a restriction on the sum of segments of overlap for a ray within the cone of propagation, i .e. between angles ⁇ / and ⁇ 3 ⁇ 4.
  • FIGs. 24A - 24C Such a target design is illustrated in FIGs. 24A - 24C.
  • a number of m icrostructures 21 1 0 in the form of m icroslabs of x-ray generating material 21 1 1 , 21 12, . . . , 21 16, . . . etc. are embedded in a substrate 2000, near the edge 2003 of a shelf 2002 in a substrate 2000, but the orientation of the microstructures has the narrowest dimension aligned with the "width" direction and the longest dimension along the length dimension.
  • the geometric volume 2770 in this example is a rectangle of volume Lr geometryi X Wr 0 i X Aw-
  • the path for x-rays at or near the take-off angle may be longer than the reabsorption upper bound.
  • low attenuation through the surrounding substrate and other x-ray microstructures may be achieved.
  • the spacing between the microstructures may be adjusted so that x-rays emerging at the maximum cone angle in the plane orthogonal to the plane of the take-off angle (i.e. in the plane of FIG. 24A) intersect a certain number of additional microstructures, achieving linear accumulation, but do not exceed the reabsorption upper bound.
  • the appropriate metric for the limitation on length segments wil l therefore be for rays at angles corresponding to certain cone angles out of the plane of the microstructures, and not the take-off angle.
  • a design rule limiting the length of the sum of segments will apply to any cone angle within a predeterm ined subset of cone angles. In some embodiments, a design rule lim iting the length of the sum of segments will apply to a majority of cone angles.
  • a general design rule can be stated that, for any ray within a predetermined subset of cone of angles greater than or equal to ⁇ / and less than or equal to (3 ⁇ 4 relative to the take-off angle ray, the sum of the segments of overlap with the x-ray generating material with in the x-ray generating volume must be smaller than 4 x ⁇ ] , . Note that for prior embodiments, this design rule may also be used rather than using the ray along the take-off angle to define the amount of x-ray generating material within a giving x-ray generating volume.
  • Design rules may also be placed on having a minimum length for sums of segments of overlap, to ensure that at least some accumulation of x-rays may occur.
  • the sum of the segments of overlap with the x-ray generating material within the x-ray generating volume must be greater than 0.3 x ⁇ L .
  • the sum of the segments of overlap with the x-ray generating material within the x-ray generating volume must be greater than 1 .0 x ⁇ L .
  • the sum of the segments of overlap with the x-ray generating material within the x-ray generating volume must be less than 1 x ⁇ L and in other embodiments this may be 2.0 x ⁇ L .
  • the depth D M of the structures of x-ray generating material may be determined by any number of factors, such as the ease of reliably manufacturing embedded structures of certain dimensions, the thermal load and thermal expansion of the embedded structures, a minimum thickness to m inimize source degradation due to delam ination or evaporation, etc.
  • the depth of the x-ray structures D M measured from the target surface should be limited to be less than 5 times the penetration depth of the electrons into the x-ray target substrate material. This ensures that the depth of the structures of x-ray generating material, which typically have poorer thermal properties than the substrate, is m inim ized, as typical ly only the portion closer to the surface is efficient at generating characteristic x-rays. Although some x-rays are generated at lower depths, there is also associated heat generation. In some embodiments, the depth of the x-ray generating material is preferred to be a fraction (e.g.
  • the depth of the x-ray generating material is preferred to be a fraction (e.g. 1 /2) of the electron penetration depth in the substrate material. In some embodiments, the depth of the x-ray generating material is preferred to be half of the CSDA depth in the substrate material.
  • the disclosed embodiments of the invention are preferably operated at takeoff angles less than or equal to 3°, and for some embodiments at 0° take-off angle, substantially lower than for conventional x-ray sources.
  • This is enabled by the structured nature of the x-ray source and the incorporation of an x-ray substrate, as discussed above, comprised of a material or structure that reduces or m inim izes self-absorption of the x-ray energies of interest generated by the x-ray target.
  • FIG. 25 illustrates the matching of the annular cone as defined in the previous embodiments with an aperture or window 2790 and/or beam stop 2794 in the system .
  • This annular output can be selected to match the acceptance angle of an x- ray optical element, such as a capillary optic with a reflecting inner surface used for directing (e.g. focusing or collimating) the generated x-ray beam for downstream applications.
  • the predeterm ined cone of x-rays generated by the x-ray source can be defined to correspond to the angles and dimensions of such downstream optical elements.
  • a central beamstop to block the x-rays propagating at the take-off angle ⁇ / (which typically wil l not be collected by the downstream optical elements such as monocapillaries) can also be used, with the propagation angles blocked by the beam stop being those that correspond to the inner diameter of the predetermined annular x-ray cone.
  • annular cones may be defined by the acceptance angles of downstream optics, i.e. by the numerical aperture of such optics, or other parameters that may occur in such systems. Matching the volume to, for example, the depth-of-focus range for a collecting optic or to the critical angle of the reflecting surface of a collecting optic may maximize the number of useful x-rays, while limiting the total power that must be expended to generate them.
  • the angular range for the annular cone of x-rays is generally specified by having the inner cone angle ⁇ 1 being greater than 2 mrad relative to the take-off angle, and having the outer cone angle ⁇ 2 be less than or equal to 50 mrad relative to the take-off angle.
  • FIG. 26 presents a cross-section view of a rotating anode in the form of a cyl inder 51 02 as may be inserted into a system as was illustrated in FIG. 17A.
  • the cylinder 51 02 is mounted on a rotating shaft 530, and has a core 5050 of a thermal ly conducting material such as copper.
  • a layer of substrate material 5000 such as diamond or CVD diamond has been formed, and embedded in this substrate are a number of rings 57 1 1 , 57 12. . . .. 57 1 7 comprising x-ray generating material.
  • the "length" (parallel to the shaft axis in this illustration, and perpendicular to the local normal n in the region under bombardment) of each ring may be comparable to the length discussed for the set of microstructures i llustrated in FIG. 1 0 (i.e. micron-scale), and the spacing may be comparable to L (also micron-scale).
  • the substrate 5000 may also be comparable to the depth discussed in the previous embodiments (i.e. micron scale, and related to either the penetration depth or the CSDA depth for either the x-ray generating material or the substrate.)
  • the "width”, however, is the circumference, as the rings 571 0 circle the entire cylinder 5 1 00.
  • a predetermined take-off angle ⁇ / may be designated, along with a cone of angles ranging from ⁇ 1 to ⁇ 2 defined relative to the take-off angle. These angles are generally selected to correspond to x-rays that the will be collected downstream to form a beam for use in x-ray optical systems.
  • the take- off angle is at 0°, making use of the x-rays that linearly accumulate through the set 5710 of rings comprising x-ray generating material.
  • the cylinder 5 1 02 may additionally have a notch 5002 near the x-ray generating rings 5710, comparable to the shelf illustrated in the previous planar target configurations.
  • FIG. 27 presents a cross-section view of another embodiment of a rotating anode in the form of a cylinder 5 105 as may be inserted into a system as was illustrated in FIG . 1 7A.
  • the cylinder 5 105 is mounted on a rotating shaft 530, with a conducting core 5050 and an outer coating of a substrate material 5005, in which a set 5720 of rings comprising x-ray generating material 5721 , 5722, 5726 are embedded.
  • the cylinder is beveled at an angle in the region of the x-ray generating volume, and the take-off angle is at a non-zero angle & / , sim ilar to the configuration for the planar geometry of FIG. 19C.
  • the bevel angle is selected so that linear accumulation through the set 5720 of rings may sti ll occur.
  • the cylinder 5 1 05 may also be fabricated with a interface layer 5003, which may be provide a coupling between the beveled substrate 5005 and the core 5055.
  • a compact source for high brightness x-ray generation is disclosed.
  • the higher brightness is achieved through electron beam bombardment of multiple regions aligned with each other to achieve a linear accumulation of x-rays.
  • This may be achieved through the use of x-ray targets that comprise m icrostructures of x-ray generating materials fabricated in close thermal contact with a substrate with high thermal conductivity. This allows heat to be more efficiently drawn out of the x-ray generating material, and allows bombardment of the x-ray generating material with higher electron density and/or higher energy electrons, leading to greater x-ray brightness.
  • the orientation of the m icrostructures allows the use of a take-off angle at or near 0°, allowing the accumulation of x-rays from several microstructures to be aligned and be used to form a beam in the shape of an annular cone.
  • a high brightness x-ray source comprising:
  • said target having a predeterm ined surface facing the electron beam emitter
  • said x-ray generating volume comprising:
  • a plurality of discrete structures comprising a second selected x-ray generating material that make up a predetermined volume fraction
  • said source additionally having an x-ray beam axis
  • the first selected material is selected from the group consisting of:
  • the x-ray generating volume is defined by the overlap
  • the take-off angle is less than 3 degrees.
  • the discrete structures comprising a second selected x-ray generating material are formed from a powder of the selected x-ray generating material
  • the discrete structures comprising a second selected x-ray generating material are embedded into the substrate of first selected material, such that
  • the x-ray generating volume comprises
  • the predetermined geometric volume is defined as the contiguous volume
  • the second selected x-ray generating material is selected from the group consisting of: aluminum, titanium, vanadium, chrom ium, manganese, iron, cobalt, nickel, copper, gallium, zinc, yttrium, zirconium, molybdenum, niobium, ruthenium, rhodium, palladium, si lver, tin, iridium, tantalum, tungsten, indium, cesium, barium, germanium, gold, platinum, lead, and combinations and alloys thereof.
  • said second x-ray generating material has a linear attenuation length ⁇ L corresponding to said x-ray energy
  • electrons from the electron beam emitter are selected to have a energy
  • At least one overcoat having a thickness of less than 20 microns
  • the material of the at least one overcoat is selected from the group consisting of: beryl lium, diamond, poiycrystalline diamond, CVD diamond, diamond-like carbon, graph ite, silicon, boron nitride, silicon carbide, and sapphire.
  • beryl lium diamond, poiycrystalline diamond, CVD diamond, diamond-like carbon, graph ite, silicon, boron nitride, silicon carbide, and sapphire.
  • the material of the at least one overcoat is selected from the group consisting of: graphene, si lver, copper, gold, tungsten, aluminum, chromium, tin, and titanium.
  • the target is cylindrically symmetric
  • the supporting core comprises copper.
  • the substrate has a thickness
  • the radius of curvature of the substrate is greater than 20 m illimeters.
  • a high brightness x-ray source comprising:
  • said target having a predetermined surface facing the electron beam emitter, and having, within the target and adjacent to said predetermined surface,
  • said x-ray generating volume comprising
  • a plurality of discrete structures comprising a second selected x-ray generating material that make up a predetermined volume fraction
  • said source additionally having a predefined set of x-ray propagation cone angles having an apex centered at the m idpoint of the x-ray generating volume
  • the x-ray generating volume is defined by the overlap
  • the first selected material is selected from the group consisting of:
  • the second selected x-ray generating material is selected from the group consisting of: aluminum, germanium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, gall ium, zinc, yttrium, zirconium, molybdenum, niobium, ruthen ium, rhodium, palladium, silver, tin, iridium, tantalum, tungsten, indium, cesium, barium, germanium, gold, platinum, lead, and combinations and alloys thereof.
  • said second x-ray generating material has a linear attenuation length ⁇ L

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  • X-Ray Techniques (AREA)

Abstract

L'invention concerne une source compacte servant à la génération de rayons X à haute luminosité. Cette plus haute luminosité est obtenue par bombardement par faisceau électronique de multiples régions alignées les unes avec les autres en vue de réaliser une accumulation linéaire de rayons X. Ceci peut être obtenu par utilisation de cibles de rayons X qui comprennent des microstructures de matériaux générateurs de rayons X fabriquées en contact thermique étroit avec un substrat doté d'une conductivité thermique élevée. Ceci permet d'évacuer plus efficacement la chaleur du matériau générateur de rayons X et permet un bombardement du matériau générateur de rayons X avec une plus haute densité d'électrons et/ou des électrons à plus haute énergie, conduisant à une plus grande luminosité des rayons X. L'orientation des microstructures permet d'utiliser un angle de décollage de 0° ou proche de 0°, permettant d'aligner l'accumulation de rayons X provenant de plusieurs microstructures et de l'utiliser en vue de former un faisceau en forme de cône annulaire.
PCT/US2016/063884 2016-05-27 2016-11-28 Sources de rayons x divergents utilisant une accumulation linéaire Ceased WO2017204850A1 (fr)

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Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10247683B2 (en) 2016-12-03 2019-04-02 Sigray, Inc. Material measurement techniques using multiple X-ray micro-beams
US10269528B2 (en) 2013-09-19 2019-04-23 Sigray, Inc. Diverging X-ray sources using linear accumulation
US10297359B2 (en) 2013-09-19 2019-05-21 Sigray, Inc. X-ray illumination system with multiple target microstructures
US10295485B2 (en) 2013-12-05 2019-05-21 Sigray, Inc. X-ray transmission spectrometer system
US10295486B2 (en) 2015-08-18 2019-05-21 Sigray, Inc. Detector for X-rays with high spatial and high spectral resolution
US10304580B2 (en) 2013-10-31 2019-05-28 Sigray, Inc. Talbot X-ray microscope
US10349908B2 (en) 2013-10-31 2019-07-16 Sigray, Inc. X-ray interferometric imaging system
US10352880B2 (en) 2015-04-29 2019-07-16 Sigray, Inc. Method and apparatus for x-ray microscopy
WO2019145493A1 (fr) * 2018-01-26 2019-08-01 Carl Zeiss Industrielle Messtechnik Gmbh Cible pour une source de rayonnement, source de rayonnement pour la génération d'un rayonnement électromagnétique invasif, utilisation d'une source de rayonnement et procédé pour la fabrication d'une cible pour une source de rayonnement
US10401309B2 (en) 2014-05-15 2019-09-03 Sigray, Inc. X-ray techniques using structured illumination
US10416099B2 (en) 2013-09-19 2019-09-17 Sigray, Inc. Method of performing X-ray spectroscopy and X-ray absorption spectrometer system
US10578566B2 (en) 2018-04-03 2020-03-03 Sigray, Inc. X-ray emission spectrometer system
WO2020051221A3 (fr) * 2018-09-07 2020-04-16 Sigray, Inc. Système et procédé d'analyse de rayons x sélectionnable en profondeur
US10656105B2 (en) 2018-08-06 2020-05-19 Sigray, Inc. Talbot-lau x-ray source and interferometric system
US10658145B2 (en) 2018-07-26 2020-05-19 Sigray, Inc. High brightness x-ray reflection source
US10845491B2 (en) 2018-06-04 2020-11-24 Sigray, Inc. Energy-resolving x-ray detection system
US10962491B2 (en) 2018-09-04 2021-03-30 Sigray, Inc. System and method for x-ray fluorescence with filtering
USRE48612E1 (en) 2013-10-31 2021-06-29 Sigray, Inc. X-ray interferometric imaging system
US11152183B2 (en) 2019-07-15 2021-10-19 Sigray, Inc. X-ray source with rotating anode at atmospheric pressure
DE102018010288B4 (de) 2018-01-26 2022-12-08 Carl Zeiss Industrielle Messtechnik Gmbh Target für eine Strahlungsquelle, Strahlungsquelle zum Erzeugen invasiver elektromagnetischer Strahlung und Verfahren zum Herstellen eines Targets für eine Strahlungsquelle
US12181423B1 (en) 2023-09-07 2024-12-31 Sigray, Inc. Secondary image removal using high resolution x-ray transmission sources
US12278080B2 (en) 2022-01-13 2025-04-15 Sigray, Inc. Microfocus x-ray source for generating high flux low energy x-rays
EP4531071A3 (fr) * 2023-09-07 2025-07-09 GE Precision Healthcare LLC Anode de tube à rayons x avec piste de foyer à zone optimisée
US12360067B2 (en) 2022-03-02 2025-07-15 Sigray, Inc. X-ray fluorescence system and x-ray source with electrically insulative target material

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110038455A1 (en) * 2009-04-16 2011-02-17 Silver Eric H Monochromatic x-ray methods and apparatus
US20110142204A1 (en) * 2009-12-16 2011-06-16 Yun Zou Apparatus for modifying electron beam aspect ratio for x-ray generation
US20130223594A1 (en) * 2010-11-08 2013-08-29 Koninklijke Philips Electronics N.V. Determining changes in the x-ray emission yield of an x-ray source
JP2015002074A (ja) * 2013-06-14 2015-01-05 キヤノン株式会社 透過型ターゲットおよび該透過型ターゲットを備える放射線発生管、放射線発生装置、及び、放射線撮影装置
US20150110252A1 (en) * 2013-09-19 2015-04-23 Wenbing Yun X-ray sources using linear accumulation

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110038455A1 (en) * 2009-04-16 2011-02-17 Silver Eric H Monochromatic x-ray methods and apparatus
US20110142204A1 (en) * 2009-12-16 2011-06-16 Yun Zou Apparatus for modifying electron beam aspect ratio for x-ray generation
US20130223594A1 (en) * 2010-11-08 2013-08-29 Koninklijke Philips Electronics N.V. Determining changes in the x-ray emission yield of an x-ray source
JP2015002074A (ja) * 2013-06-14 2015-01-05 キヤノン株式会社 透過型ターゲットおよび該透過型ターゲットを備える放射線発生管、放射線発生装置、及び、放射線撮影装置
US20150110252A1 (en) * 2013-09-19 2015-04-23 Wenbing Yun X-ray sources using linear accumulation

Cited By (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10416099B2 (en) 2013-09-19 2019-09-17 Sigray, Inc. Method of performing X-ray spectroscopy and X-ray absorption spectrometer system
US10269528B2 (en) 2013-09-19 2019-04-23 Sigray, Inc. Diverging X-ray sources using linear accumulation
US10297359B2 (en) 2013-09-19 2019-05-21 Sigray, Inc. X-ray illumination system with multiple target microstructures
US10976273B2 (en) 2013-09-19 2021-04-13 Sigray, Inc. X-ray spectrometer system
US10304580B2 (en) 2013-10-31 2019-05-28 Sigray, Inc. Talbot X-ray microscope
US10653376B2 (en) 2013-10-31 2020-05-19 Sigray, Inc. X-ray imaging system
US10349908B2 (en) 2013-10-31 2019-07-16 Sigray, Inc. X-ray interferometric imaging system
USRE48612E1 (en) 2013-10-31 2021-06-29 Sigray, Inc. X-ray interferometric imaging system
US10295485B2 (en) 2013-12-05 2019-05-21 Sigray, Inc. X-ray transmission spectrometer system
US10401309B2 (en) 2014-05-15 2019-09-03 Sigray, Inc. X-ray techniques using structured illumination
US10352880B2 (en) 2015-04-29 2019-07-16 Sigray, Inc. Method and apparatus for x-ray microscopy
US10295486B2 (en) 2015-08-18 2019-05-21 Sigray, Inc. Detector for X-rays with high spatial and high spectral resolution
US10466185B2 (en) 2016-12-03 2019-11-05 Sigray, Inc. X-ray interrogation system using multiple x-ray beams
US10247683B2 (en) 2016-12-03 2019-04-02 Sigray, Inc. Material measurement techniques using multiple X-ray micro-beams
DE102018010288B4 (de) 2018-01-26 2022-12-08 Carl Zeiss Industrielle Messtechnik Gmbh Target für eine Strahlungsquelle, Strahlungsquelle zum Erzeugen invasiver elektromagnetischer Strahlung und Verfahren zum Herstellen eines Targets für eine Strahlungsquelle
GB2583878B (en) * 2018-01-26 2022-08-17 Zeiss Carl Industrielle Messtechnik Gmbh Target for a radiation source, radiation source for generating invasive electromagnetic radiation,use of a radiation source, and method for producing a target
GB2583878A (en) * 2018-01-26 2020-11-11 Zeiss Carl Industrielle Messtechnik Gmbh Target for a radiation source, radiation source for generating invasive electromagnetic radiation,use of a radiation source, and method for producing a target
US11145482B2 (en) 2018-01-26 2021-10-12 Carl Zeiss Industrielle Messtechnik Gmbh Target for a radiation source, radiation source for generating invasive electromagnetic radiation, method of operating a radiation source, and method for producing a target for a radiation source
WO2019145493A1 (fr) * 2018-01-26 2019-08-01 Carl Zeiss Industrielle Messtechnik Gmbh Cible pour une source de rayonnement, source de rayonnement pour la génération d'un rayonnement électromagnétique invasif, utilisation d'une source de rayonnement et procédé pour la fabrication d'une cible pour une source de rayonnement
US10578566B2 (en) 2018-04-03 2020-03-03 Sigray, Inc. X-ray emission spectrometer system
US10989822B2 (en) 2018-06-04 2021-04-27 Sigray, Inc. Wavelength dispersive x-ray spectrometer
US10845491B2 (en) 2018-06-04 2020-11-24 Sigray, Inc. Energy-resolving x-ray detection system
US10658145B2 (en) 2018-07-26 2020-05-19 Sigray, Inc. High brightness x-ray reflection source
US10991538B2 (en) 2018-07-26 2021-04-27 Sigray, Inc. High brightness x-ray reflection source
US10656105B2 (en) 2018-08-06 2020-05-19 Sigray, Inc. Talbot-lau x-ray source and interferometric system
US10962491B2 (en) 2018-09-04 2021-03-30 Sigray, Inc. System and method for x-ray fluorescence with filtering
US11056308B2 (en) 2018-09-07 2021-07-06 Sigray, Inc. System and method for depth-selectable x-ray analysis
WO2020051221A3 (fr) * 2018-09-07 2020-04-16 Sigray, Inc. Système et procédé d'analyse de rayons x sélectionnable en profondeur
US11152183B2 (en) 2019-07-15 2021-10-19 Sigray, Inc. X-ray source with rotating anode at atmospheric pressure
US12278080B2 (en) 2022-01-13 2025-04-15 Sigray, Inc. Microfocus x-ray source for generating high flux low energy x-rays
US12360067B2 (en) 2022-03-02 2025-07-15 Sigray, Inc. X-ray fluorescence system and x-ray source with electrically insulative target material
US12181423B1 (en) 2023-09-07 2024-12-31 Sigray, Inc. Secondary image removal using high resolution x-ray transmission sources
EP4531071A3 (fr) * 2023-09-07 2025-07-09 GE Precision Healthcare LLC Anode de tube à rayons x avec piste de foyer à zone optimisée
US12512289B2 (en) 2023-09-07 2025-12-30 GE Precision Healthcare LLC X-ray tube anode with optimized area focal spot track

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