X-ray tube and X-ray CT apparatus

An X-ray CT apparatus, comprising an X-ray tube configured to radiate an X-ray, a detector configured to detect the X-ray radiated from the X-ray tube, a reconstruction part configured to reconstruct an image from projection data based on detection by the detector, and a controller configured to control a scan by detection of the X-ray including control of the X-ray tube, wherein the X-ray tube includes:

• a Wehnelt electrode having a dent inside;
• a filament arranged in the dent of the Wehnelt electrode and configured to emit an electron beam when electricity is passed therethrough;
• an anode configured to emit an X-ray in response to the incident electron beam;
• an electrode part configured by at least one pair of electrode members, the electrode members facing each other across a path of the electron beam, a voltage being applied to each of the electrode members;
• a voltage controller configured to control the voltage applied to the electrode part;
• and
• a shield member arranged in contact with the Wehnelt electrode and configured to cover part of the dent by a projecting part.