| 摘要 |
<p>An industrial X-ray tube formed by accommodating a cathode and anode in a container having an evacuated interior, in which electrons emitted from the cathode are caused to strike the anode and X-rays are emitted from the anode. The cathode is formed from graphite. The graphite is a layered crystal obtained by layering a plurality of carbon hexagonal planes. The graphite is cut based on crystal axes of the carbon hexagonal planes. The resulting cut surface is caused to function as an electron-emitting surface. For example, directions of an a- and b-crystal axis may be set so as to be arbitrary between each of the layers of the carbon hexagonal planes, the graphite may be cut along a surface parallel to the c-axis, and the resulting cut surface may be caused to function as an electron-emitting surface. The graphite may also be cut along a surface orthogonal to the c-axis.</p> |
