Determination of the sample thicknesses by intensity ratio measurement by energy dispersive x-ray fluorescence spectrometry

A procedure for the determination of the thickness of Au and Ag films and f oils coated on a metallic Cu foil (substrate) is described. The procedure i s based on the measurements of the fluorescence intensity ratios for two li nes from the substrate element, excited by 59.5 keV photons emitted from a filtered Am-241 radioisotope source. The result of the procedure yielded be tween 0.039x10(-5) and 4.3322x10(-5) g/cm(2) for Au and between 0.0394x10(- 5) and 5.8364x10(-5) g/cm(2) for Ag. These are tested by gravimetric measur ements. The proposed procedure can also be employed to determine the densit y of the covering material or the incoming and outgoing angles of the radia tion if the film thickness is known.