X-rays can be used for material identification. X-ray beam purity, target adhesion the x-ray window, and a robust hermetic seal of the x-ray window are useful. To achieve these objectives, a target 17 can be mounted by an adhesion-layer 16 on the x-ray window. The adhesion-layer 16 can include chromium. A sealing-layer 13 can seal the x-ray window to a flange 19. Material of the sealing-layer 13 can be different from material of the adhesion-layer 16. There can be a gap 21 between the flange 19 and the target 17. There can be a conductive-layer 18 on the x-ray window 14 in the gap 21. A thickness Ts of the adhesion-layer 16 between the sealing-layer 13 and the x-ray window 14 can be different than a thickness Tt of the adhesion-layer 16 between the target 17 and the x-ray window 14.

A mounted x-ray window has an x-ray window mounted on a flange of a housing and spanning and covering an aperture. The x-ray window includes one or more layers each having a low atomic number less than 14. An additive passivation film is associated with the x-ray window and has a thickness greater than 5 nanometers (nm) and less than a thickness of each of the one or more layers. The additive passivation film can be deposited by atomic layer deposition.

In an embodiment an X-ray source includes an electron source configured to emit electrons, an acceleration set-up configured to accelerate the emitted electrons and a transmission window downwards of the acceleration set-up, wherein the transmission window is configured to let through X-rays generated by the accelerated electrons, wherein the transmission window is located either in a straight extension of a line-of-flight of the accelerated electrons or off the line-of-flight and past the acceleration set-up, wherein the transmission window comprises a carbon carrier, and wherein the carbon carrier comprises sp2-hybridized carbon.

An x-ray window 60 or 70 can include a thin film 61 sealed to a support structure 10. The support structure 10 can include an outer ring 11 encircling an outer ring aperture 15, an inner ring 12 encircling an inner aperture, and multiple spokes 13. The inner ring 12 can be located in the outer ring aperture 15. The inner ring 12 can be attached to the outer ring 11 by the multiple spokes 13. The support structure 10 shapes can optimize strength and percent open area.

In some embodiments, a system may include an X-ray tube assembly having an anode disk assembly. The system may include a motor configured to rotate the anode disk assembly. The system may include one or more pumps configured to draw a vacuum in the X-ray tube assembly. The system may include a cooling system configured to cool the anode disk assembly. In some embodiments, a method may include drawing a vacuum in an X-ray tube assembly with one or more pumps. The method may include rotating an anode disk assembly of the X-ray tube assembly. The method may include cooling the anode disk assembly with a cooling system. The method may include activating a power supply to produce an electron beam. The electron beam may interact with an X-ray generating layer of the anode disk assembly to produce an X-ray beam oriented to impinge on a sample.

A mounted x-ray window 10 and 20 can include an x-ray window 18 mounted on the flange 11f of a housing 11. The x-ray window 18 can include the following layers: a top strong layer 17, a stress-relief layer 16, a bottom strong layer 15, an adhesive layer 14 then a support ring 13. These layers can have a material composition and thickness for optimizing x-ray window low gas permeability, low outgassing, high strength, low visible and infrared light transmission, high x-ray flux, low atomic number materials, corrosion resistance, high reliability, and low-cost.

An x-ray window 60 or 70 can include a thin film 61 sealed to a support structure 10. The support structure 10 can include an outer ring 11 encircling an outer ring aperture 15, an inner ring 12 encircling an inner aperture, and multiple spokes 13. The inner ring 12 can be located in the outer ring aperture 15. The inner ring 12 can be attached to the outer ring 11 by the multiple spokes 13. The support structure 10 shapes can optimize strength and percent open area.