COMPENSATION OF ANODE WOBBLE FOR X-RAY TUBES OF THE ROTARY-ANODE TYPE

摘要

The present invention refers to X-ray tubes of the rotary-anode type for generating a fan beam of X-rays. More particularly, the invention is concerned with a system and method for compensating a class of system-related disturbances of the focal spot position FS on a target area AT of the rotating anode RA and particularly for compensating the anode wobble in an X-ray tube XT of the aforementioned type, which occurs as a periodically wobbling inclination angle of the anode disk's rotational plane with respect to an ideal rotational plane (z = 0) which is oriented normal to the rotational axis z of the rotary shaft S on which the anode disk RA is inclinedly mounted due to an inaccuracy during its production process. For this purpose, the electron beam generated by a thermoionic or other type of electron emitter of the tube's cathode C and thus the focal spot position FS on a target area AT of the anode disk's X-ray generating surface (anode target) are steered such that the focal spot FS stays within the plane PCXB of the central X-ray fan beam CXB.