Patent ID: 7486777

Claim:
A cooler that circulates cooling fluid to cool down an X-ray tube, comprising: a circulation unit that has a first end unit in which an outlet to deliver the cooling fluid is formed, and a second end unit in which an inlet is formed, and takes in the cooling fluid from the inlet to cool thus taken-in cooling fluid and deliver the cooling fluid to the outlet; and an expansion mechanism that has a vessel which is attached to the circulation unit and which has an opening through which cooling fluid flowing in the circulation unit comes in and goes out, and a bellows that divides the inside of the vessel into a first chamber communicating with the opening and a second chamber; wherein the first end unit and the second end unit being detachably coupled to the X-ray tube, and being closed when being uncoupled from the X-ray tube, and wherein the expansion mechanism is switched between a first state in which coming in and going out of ambient atmosphere to and from the second chamber is shut off to restrict coming in and going out of the cooling fluid to and from the first chamber, and a second state in which coming in and going out of ambient atmosphere to and from the second chamber is released to allow coming in and going out of the cooling fluid to and from the first chamber.