An X-ray generator capable of reliably reducing an X-ray focal spot size without depending on the focal spot size of an electron beam on a target. Providing, within the irradiation range of an electron beam B of a target laminated structure 3 comprising a target 2 and an X-ray irradiation window 1, a low X-ray absorptivity region 3a of localized low X-ray absorptivity in the irradiation direction of the electron beam B results in the suppression of emission to the outside of X-rays from among the X-rays generated as a result of the irradiation of the electron beam B onto the target 2 that are from regions other than the low X-ray absorptivity region 3a, and an X-ray focal spot of a size corresponding to the size of the low X-ray absorptivity region 3a is obtained regardless of the size of the irradiation region of the electron beam B.

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.

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.

A method is for manufacturing a multilayer radiation window for an X-ray measurement apparatus. The method includes: producing a gas diffusion stop layer made of silicon nitride on a polished surface of a carrier; producing at least one combined layer on an opposite side of the gas diffusion stop layer than the carrier; attaching the combined structure including the carrier, the gas diffusion stop layer, the at least one combined layer to a region around an opening in a support structure with the at least one combined layer facing the support structure; and etching away the carrier. The at least one combined layer includes: a light attenuation layer made of aluminium, and a strengthening layer. A radiation window is manufactured with the method.

A transmission-target x-ray tube can include an x-ray window 12 mounted on a window-housing 13. The window-housing 13 can be made of a high density material with a high atomic number, and can include an aperture 13.sub.a with an increasing-inner-diameter region 23 for blocking x-rays and electrons.

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.

In an embodiment a radiation detector includes a semiconductor body configured to detect X-rays having a radiation entrance side, an electrically conductive window layer areally arranged to the radiation entrance side, the window layer having boron and/or carbon and having a thickness of at most 20 nm and an electrically conductive bar structure on the window layer and in electrical contact with the window layer.

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.

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.