Abstract: A method and computer program software product for establishing an areal density of an elemental constituent of one layer of a stack of layers of material overlying a substrate. Incident penetrating radiation excites characteristic x-ray fluorescent radiation in multiple lines associated with each of one or more elements. Areal densities of successive layers are determined by self-consistent solution of equations relating the ratios of intensities of the characteristic fluorescence lines of successive elements.

Abstract: A method and device for calibrating the energy response of detectors of photons in the range from about 0.5 keV to at least 100 keV. The device makes use of the inherent property of a polarizable crystal such as a pyroelectric crystal to produce monoenergetic x-rays when the crystal is heated or cooled in a partial vacuum. Specific calibration energies of x-ray emission, may be selected for the application of the user by selection of a coating to the pyroelectric crystal and an external foil. The calibration device may be disposed within the same housing as a penetrating radiation detector.