X-ray apparatus with filter comprising filter elements with adjustable x-ray absorption and x-ray absorption sensor

Abstract

An X-ray device with an X-ray source to produce a beam of X-ray radiation, an X-ray detector to detect this radiation and an X-ray filter with filter elements which is positioned between the X-ray source and the X-ray detector to attenuate the X-ray beam in each independent filter element individually. Even filter element ( ) can contain a fluid ( ) which is electrically conducting and X-ray absorbing, which is supplied via a transport channel ( ), whereas the value of the X-ray absorption of each filter element can discretely adjusted by a stepwise adjustment of the level of the fluid ( ) within each filter element. Each filter element comprises a first electrode, which is located in the wall of the filter element and is segmented in the length direction of the filter element ( ), the segments being electrically combined in tow subgroups ( ) in order to apply an electric potential to the wall segments of the filter element to achieve a step-wise filling of the inner volume ( ) by fluid ( ). The measuring means ( ) are provided to detect the length of the fluid column ( ) within the inner volume ( ) of the filter element ( ).