This disclosure provides systems, methods, and apparatus related to graphene. In one aspect, a method includes submerging a frame support in an etching solution that is contained in a container. A growth substrate, a graphene sheet disposed on the growth substrate, and a primary support disposed on the graphene sheet is placed on a surface of the etching solution. The growth substrate is dissolved in the etching solution to leave the graphene sheet and the primary support floating on a surface of the etching solution. The etching solution in the container is replaced with a washing solution. The washing solution is removed from the container so that the graphene sheet becomes disposed on the frame support.

An x-ray window can include an adhesive layer sandwiched between and providing a hermetic seal between a thin film and a housing. The adhesive layer can include liquid crystal polymer. The liquid crystal polymer can be opaque, gas-tight, made of low atomic number elements, able to withstand high temperature, low outgassing, low leakage, able to relieve stress in the x-ray window thin film, capable of bonding to many different materials, or combinations thereof.

An analytical X-ray tube with an anode target material that emits characteristic X-rays in response to excitation by an electron beam may include any of several advantageous features. The target material is deposited on a diamond substrate layer, and a metal carbide intermediate layer may be provided between the target material and substrate that provides enhanced bonding therebetween. An interface layer may also be used that provides an acoustic impedance matching between the target material and the substrate. For a low thermal conductivity target material, a heat dissipation layer of a higher thermal conductivity material may also be included between the target material and substrate to enhance thermal transfer. The target material may have a thickness that corresponds to a maximum penetration depth of the electrons of the electron beam, and the structure may be such that a predetermined temperature range is maintained at the substrate interface.

Disclosed is a radiation window structure. The radiation window structure including a substrate made of silicon nitride and a coating layer grown from a vapor phase on outer surface of the substrate. Also disclosed is a method for manufacturing a radiation window structure.

An x-ray window can include a thin film that comprises boron. The thin film can be relatively thin, such as for example 200 nm. This x-ray window can be strong; can have high x-ray transmissivity; can be impervious to gas, visible light, and infrared light; can be easy of manufacture; can be made of materials with low atomic numbers, or combinations thereof. The thin film can include an aluminum layer. A support structure can provide additional support to the thin film. The support structure can include a support frame encircling an aperture and support ribs extending across the aperture with gaps between the support ribs. The support structure can also include boron ribs aligned with the support ribs.

A window member for separating an internal environment of an x-ray device from an environment external to the x-ray device is provided. The window member comprises a substrate and a coating layer disposed upon a surface of the substrate. The substrate is formed from a polycrystalline material and is substantially transparent to low-energy x-rays. The coating layer is non-porous, covers the crystal grains at the surface of the substrate and extends into the grain boundaries therebetween, such that the coating layer forms an impermeable barrier between the substrate and the external environment.

An x-ray window can include a thin film that comprises boron. The thin film can be relatively thin, such as for example 200 nm. This x-ray window can be strong; can have high x-ray transmissivity; can be impervious to gas, visible light, and infrared light; can be easy of manufacture; can be made of materials with low atomic numbers, or combinations thereof. The thin film can include an aluminum layer. A support structure can provide additional support to the thin film. The support structure can include a support frame encircling an aperture and support ribs extending across the aperture with gaps between the support ribs. The support structure can also include boron ribs aligned with the support ribs.

The x-ray windows herein can have 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. The x-ray window can include a film 11 with a polymer layer 22 and a graphite layer 21. The film 11 can consist essentially of graphite and polymer. Most of the film 11 can be the graphite layer 21. The polymer layer 22 can be a small portion of the film 11.

An x-ray window can include an adhesive layer sandwiched between and providing a hermetic seal between a thin film and a housing. The adhesive layer can include liquid crystal polymer. The liquid crystal polymer can be opaque, gas-tight, made of low atomic number elements, able to withstand high temperature, low outgassing, low leakage, able to relieve stress in the x-ray window thin film, capable of bonding to many different materials, or combinations thereof.

For manufacturing a radiation window for an X-ray measurement apparatus, an etch stop layer is first produced on a polished surface of a carrier. A thin film deposition technique is used to produce a boron carbide layer on an opposite side of the etch stop layer than the carrier. The combined structure including the carrier, the etch stop layer, and the boron carbide layer is attached to a region around an opening in a support structure with the boron carbide layer facing the support structure. The middle area of carrier is etched away, leaving an additional support structure.