An embodiment of the inventive concept provides an X-ray tube including a chamber having a hollow pillar shape using a first axis as a central axis, a cathode electrode disposed on a bottom surface of the chamber, an emitter provided at a position at which the cathode electrode meets the first axis, an anode electrode including a through-hole using the first axis as a central axis and a target layer inclined to the first axis, a gate electrode disposed between the cathode electrode and the anode electrode and having an opening exposing the emitter, a focusing electrode disposed between the gate electrode and the anode electrode, a window spaced apart from the target layer of the anode electrode, and a window electrode provided on a top surface of the chamber to fix a side surface of the window. Here, the window electrode is grounded.

In one embodiment, an x-ray tube 15 can be used closer to a sample. An angle A.sub.1 between an anode axis 02 and an electron-beam axis 01 can be 10 and 80 and an angle A.sub.2 between the anode axis 02 and an x-ray axis 03 can be 10 and 80. In another embodiment, a cap 20 on an anode 12 can block x-rays emitted in undesired directions. The cap 20 can include an internal cavity 24, an electron-beam hole 21, an anode hole 22, and an x-ray hole 23. In another embodiment, an electrical connection between an x-ray tube 15 and a power supply 18 can be reliable and easy to manufacture. The anode 12 can include a hole 31 at an end of the anode 12 sized and shaped for insertion of an electrical connector 32.

In one embodiment, an x-ray tube 15 can be used closer to a sample. An angle A.sub.1 between an anode axis 02 and an electron-beam axis 01 can be 10 and 80 and an angle A.sub.2 between the anode axis 02 and an x-ray axis 03 can be 10 and 80. In another embodiment, a cap 20 on an anode 12 can block x-rays emitted in undesired directions. The cap 20 can include an internal cavity 24, an electron-beam hole 21, an anode hole 22, and an x-ray hole 23. In another embodiment, an electrical connection between an x-ray tube 15 and a power supply 18 can be reliable and easy to manufacture. The anode 12 can include a hole 31 at an end of the anode 12 sized and shaped for insertion of an electrical connector 32.

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.

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.

In one embodiment, an x-ray tube 15 can be used closer to a sample. An angle A.sub.1 between an anode axis 02 and an electron-beam axis 01 can be 10 and 80 and an angle A.sub.2 between the anode axis 02 and an x-ray axis 03 can be 10 and 80. In another embodiment, a cap 20 on an anode 12 can block x-rays emitted in undesired directions. The cap 20 can include an internal cavity 24, an electron-beam hole 21, an anode hole 22, and an x-ray hole 23. In another embodiment, an electrical connection between an x-ray tube 15 and a power supply 18 can be reliable and easy to manufacture. The anode 12 can include a hole 31 at an end of the anode 12 sized and shaped for insertion of an electrical connector 32.

In one embodiment, an x-ray tube 15 can be used closer to a sample. An angle A.sub.1 between an anode axis 02 and an electron-beam axis 01 can be 10 and 80 and an angle A.sub.2 between the anode axis 02 and an x-ray axis 03 can be 10 and 80. In another embodiment, a cap 20 on an anode 12 can block x-rays emitted in undesired directions. The cap 20 can include an internal cavity 24, an electron-beam hole 21, an anode hole 22, and an x-ray hole 23. In another embodiment, an electrical connection between an x-ray tube 15 and a power supply 18 can be reliable and easy to manufacture. The anode 12 can include a hole 31 at an end of the anode 12 sized and shaped for insertion of an electrical connector 32.

A radiation emitting target, a radiation generating device, and a radiography system are provided in which adhesion between a target layer and a diamond substrate is improved and stable radiation emitting properties are exhibited. A transmission type target includes a target layer, a carbon-containing region including sp2 bonds, and a diamond substrate that supports the target layer. The carbon-containing region is positioned between the target layer and the diamond substrate.

According to one embodiment, an X-ray tube includes a vacuum enclosure that maintains a vacuum inside, a cathode provided in the vacuum enclosure, which emits an electron beam, an anode target provided in the vacuum enclosure, which emits an X-ray when the electron beam emitted from the cathode enters a focal plane of the anode target, and an X-ray radiation window that allows the X-ray emitted from the focal plane of the anode target to pass therethrough, and the X-ray radiation window comprises a window member and a support for the window member, the vacuum enclosure includes a joint portion formed thereon to be joined to the support and protrude toward an outer side of the vacuum enclosure, and the support comprises a covering portion that covers an inner circumferential surface of the joint portion.

According to one embodiment, an X-ray tube includes a vacuum enclosure that maintains a vacuum inside, a cathode provided in the vacuum enclosure, which emits an electron beam, an anode target provided in the vacuum enclosure, which emits an X-ray when the electron beam emitted from the cathode enters a focal plane of the anode target, and an X-ray radiation window that allows the X-ray emitted from the focal plane of the anode target to pass therethrough, and the X-ray radiation window comprises a window member and a support for the window member, the vacuum enclosure includes a joint portion formed thereon to be joined to the support and protrude toward an outer side of the vacuum enclosure, and the support comprises a covering portion that covers an inner circumferential surface of the joint portion.