Abstract: The invention relates to an X-ray tube used to obtain radiological images in which sharpness and contrast are improved. To this end, the X-ray tube has an anode consisting, at least partially, of a massive layer made of an X-ray emitting material in which at least one hollow part demarcates a surface exposed to a beam of electrons.

Abstract: An equipped forced-convection housing unit for a rotating-anode X-ray tube comprises a flow-initiating device which is integrated in the housing unit and has the function of circulating the coolant fluid surrounding the X-ray tube. This arrangement simplifies the problems relating to supply of electric power to the motor which drives the flow-initiating device and the motor which drives the anode of the X-ray tube in rotation.

Abstract: The invention relates to an X-ray apparatus with focus position control, the focus being formed on the anode of an X-ray tube with magnetic bearings. The X-ray apparatus comprises a focus position sensing device cooperating with electronic means associated with the magnetic bearings, in order to control the position of the focus by displacing a rotor under the action of the magnetic bearings.

Abstract: A method and circuit arrangement for improving the definition of the focal spots of X-ray tubes which comprises periodically varying the bias voltage applied to the concentrating electrode of the tube, focalizing the eletron beam emitted by the filament, between a negative minimum or zero value and a negative maximum value, with a voltage waveform whose frequency is higher than 10 kilohertz, wherein this bias voltage has to assume at least the two extreme values frequently, while a direct-current high voltage is being applied between the cathode (filament) and the anode (target) during the exposure time.