New consistency tests for high-accuracy measurements of X-ray mass attenuation coefficients by the X-ray extended-range technique

An extension of the X‐ray extended‐range technique is described for measuring X‐ray mass attenuation coefficients by introducing absolute measurement of a number of foils – the multiple independent foil technique. Illustrating the technique with the results of measurements for gold in the 38–50 keV energy range, it is shown that its use enables selection of the most uniform and well defined of available foils, leading to more accurate measurements; it allows one to test the consistency of independently measured absolute values of the mass attenuation coefficient with those obtained by the thickness transfer method; and it tests the linearity of the response of the counter and counting chain throughout the range of X‐ray intensities encountered in a given experiment. In light of the results for gold, the strategy to be ideally employed in measuring absolute X‐ray mass attenuation coefficients, X‐ray absorption fine structure and related quantities is discussed.