An accurate determination of the K‐shell X‐ray fluorescence yield of silicon

A measurement of the K-shell fluorescence yield of silicon is undertaken in which identified sources of systematic errors in previous measurements are reduced or eliminated. This enables a stringent test of the only two sets of theoretical predictions available for atomic numbers less than 18. Our result ?K?=?0.0495 +/- 0.0015 is very slightly lower than the non-relativistic Hartree-Fock-Slater (HFS) prediction of 0.0514. This stringent test of the HFS predictions helps to refine the fundamental parameter database of the X-ray fluorescence analysis technique, whose importance for light elements is increasing. Our work indicates the need for new theoretical calculations of K-shell fluorescence yields for these elements. Copyright (C) 2012 John Wiley & Sons, Ltd.