X-ray generator tube having improved cooling container and X-ray imaging apparatus including the same

An X-ray generator comprising:

• an X-ray tube including a cylindrical body with two end faces;
• an electron source in the cylindrical body between the two end faces;
• a target arranged at an end face of the cylindrical body so as to face the electron source, the target generating X-rays by irradiation with electrons emitted from the electron source;
• a container in which the X-ray tube is arranged;
• insulating liquid filled between the X-ray tube and the container;
• and
• a holding member holding the cylindrical body in the container, the holding member forming a channel for the insulating liquid around the X-ray tube,
• wherein a direction in which the electron source and the target face each other is parallel to a cylindrical axis of the cylindrical body, and
• wherein a distance, which is measured parallel to the cylindrical axis, between the holding member and the outer surface of the X-ray tube at the end face where the target is arranged is twice or more as large as a minimum width of the channel.