X-ray apparatus having a control device for preventing damaging X-ray emissions

An X-ray apparatus comprising:

• an X-ray tube including:
• a rotary anode having an X-ray emitting target;
• a cathode that emits an electron beam toward said target of the rotary anode
• a rotary structure to which the anode is secured;
• a stationary structure that engages concentrically with the rotary structure;
• and
• a hydrodynamic slide bearing which has helical grooves in an engaging section of the rotary structure and stationary structure and to which a liquid-metal lubricant with a specific melting point is applied;
• a stator arranged around an outside periphery of the X-ray tube;
• a rotational driving power supply device that supplies a rotational driving electric power to the stator;
• a X-ray tube power supply device that causes an electron beam to strike an focal point track area on the rotary anode in the X-ray tube;
• and
• an X-ray emission control device that controls an operation of the X-ray tube power supply device and sets conditions of X-ray emission, wherein
• said X-ray emission control device includes:
• first prediction means that predicts how a temperature at an electron beam incident point on said focal point track area and an average temperature of said focal point track area rise with time for the anode voltage, electron beam current and the electron beam incidence duration in a case where an electron beam is caused to strike the focal point track area on the rotary anode in the X-ray tube;
• second prediction means that predicts how the average temperature of the focal point track area falls with time from the reached average temperature of the focal point track area by heat dissipation in a case where the electron beam incidence is stopped;
• and
• notifying means for notifying at every moment input permission conditions to the X-ray tube obtained on the basis of prediction results from said first and second prediction means.