Calibration device and calibration method for detector

A calibration device for a detector including a plurality of detecting elements each of which generates an electrical pulse signal with a peak value corresponding to an energy value of incident X-ray photons and counts a photon count for each peak value, the calibration device comprising:

• an X-ray tube control unit that controls a tube voltage of an X-ray tube for irradiating the detector with X-rays;
• an acquisition unit that acquires the photon count for each peak value from each of the detecting elements and acquires the tube voltage of the X-ray tube;
• a calculation unit that estimates a maximum peak value within a range in which X-ray photons are detected from values obtained by the acquisition unit and at which the peak value is maximum;
• and
• a calibration unit that calculates, for each of the detecting elements, a calibration value that associates the tube voltage acquired by the acquisition unit with the maximum peak value, wherein
• the X-ray tube control unit is configured to change the tube voltage in a state corresponding to an energy value serving as a boundary of a plurality of predetermined ranges of energy values, and
• the calibration unit is configured to calculate a calibration value for each tube voltage.