Full-foil x-ray mapping of integrated column density applied to the absolute determination of mass attenuation coefficients

Abstract

Recent measurements of mass attenuation coefficients have identified the determination of the thickness of the absorbing specimen as the major limitation to the accuracy of the measurement. We present a technique for determining the mass attenuation coefficient with high accuracy. The technique uses the integral of the density along a column extending through the thickness of the absorber, which we term the integrated column density. Attenuation measurements mapped across the entire absorber are used to determine a relative map of the integrated column density. These relative measurements are then placed on an absolute scale by comparison with the average integrated column density and are us..