X-RAY TUBE
According to one embodiment, an X-ray tube includes an envelope, an anode and a cathode structure. The anode and the cathode structure are provided opposite to each other in the envelope. The cathode structure includes a cathode and an insulator which supports the cathode and is attached to the envelope. The insulator includes a basal portion attached to the envelope, a support portion which supports the cathode at a distal end projecting from the basal portion, and a tubular projection portion which is provided to project from the basal portion and opposite to a periphery of the support portion.
1 . An X-ray tube comprising:
an envelope; and
an anode and a cathode structure which are provided opposite to each other in the envelope,
wherein the cathode structure includes a cathode and an insulator which supports the cathode and is attached to the envelope, and
the insulator includes a basal portion attached to the envelope, a support portion which supports the cathode at a distal end projecting from the basal portion, and a tubular projection portion which is provided to project from the basal portion and opposite to a periphery of the support portion.
2 . The X-ray tube of claim 1 , wherein the projection portion of the insulator includes an opposite surface which is formed such that a distance between the opposite surface and a periphery of the support portion gradually increases from a proximal end side of the projection portion to a distal end side of the projection portion in a projection direction thereof.