Patent ID: 6453013
Filing Date: 2002-09-17
Classification: G21K

Abstract:
An X-ray apparatus which is provided with an X-ray source (1) for producing X-rays (2), an X-ray detector (4) for detecting the X-rays, and a filter (12) which is arranged between the X-ray source and the X-ray detector and includes a plurality of tubular filter elements (13) for receiving an X-ray absorbing and electrically conductive liquid filling (22), first means (140) being provided for applying an electric voltage to individual filter elements (13), an X-ray absorptivity of the individual filter elements being adjustable by control of a quantity of X-ray absorbing liquid filling (22) present within the individual filter elements (13), characterized in that the filter (12) is also provided with a hydrostatic pressure control system (160) for controlling a hydrostatic pressure in the filter elements, measuring means being provided for measuring a physical quantity related to the height of a column of the X-ray absorbing liquid filling (224) within the filter elements, and with control means for controlling the hydrostatic pressure control system (160), the height of the column of the X-ray absorbing liquid filling (224) in an individual filter element being determined by the combination of the hydrostatic pressure and the electric voltage applied to the filter element.