Patent ID: 7949092

Claim:
A method for performing X-ray analysis using a device ( 1 ) comprising an X-ray tube ( 2 ) and at least one capillary lens ( 4 ) for focusing the X-rays in a micro-region at a location ( 5 ) for a sample for analysis, in addition to a detector ( 6 ) for detecting X-ray fluorescence from the sample, wherein the device further comprises at least one energy-dependent filter ( 3 ) placed in the optical path between the X-ray tube and the location ( 5 ), characterized in that the method comprises the steps of: a) determining the desired maximum dimensions (X max ) for the micro-region; b) determining the energy (E max ) of the X-rays associated with the desired maximum dimensions (S max ) for the micro-region; c) selecting a filter ( 3 ) which is adapted to block in considerable measure X-rays with an energy which is equal to or lower than a predetermined energy value, wherein the energy value is chosen to be substantially equal to the energy (E max ) determined in step b), such that the dimensions of the micro-region (S max ) are substantially bounded within predetermined permissible values.