Spectral intensity distributions from x‐ray tubes. Calculated versus experimental evaluations

Abstract

Apart from their general importance, an accurate definition of spectral intensity distributions from x‐ray tubes is required to support the development of mathematical matrix correction procedures for x‐ray fluorescence analysis. Since a direct measurement is costly, time consuming and occasionally difficult, and a purely theoretical approach is not suitable for current utilization, a simple, readily adaptable calculation procedure is very desirable. Concerning the continuum or white radiation from the x‐ray tube, such an evaluation was worked out by effecting (1) a modification to Kramers' law and (2) a refinement of the absorption correction regarding the absorption by the target itself. The new equation accounts very closely for the best known, carefully measured and corrected experimental distributions by Brown et al. and Loomis and Keith. Extended experiments are required to ensure systematization, and special steps are needed for the treatment of the characteristic radiation.

Depth profiling of iron impurities on GaAs surfaces using total reflection X-ray fluorescence

“…The continuum intensity distributions from X-ray tubes have been described in detail by Tertian and Broll [5]. In the present case the distribution from a Rh-target was modified by the absorption of a Mo-foil.…”

General approach for quantitative energy dispersive x-ray fluorescence analysis based on fundamental parameters

“…In order to make eq 1 generally applicable to any excitation source (direct tube, secondary target, radioactive source, or synchrotron radiation), the intensity distribution I(En) of the excitation source is required. Experimentally determined and calculated X-ray tube spectral distributions have been reported in the literature (25)(26)(27)(28)(29)(30)(31)(32)(33).…”

Mathematical matrix correction procedures for x‐ray fluorescence analysis. A critical survey

“…Let us mention that Rousseau in his last paper34 retains the linear variation (i.e. a3=0) for all* and reinstates crossed terms, hence the equation (ajj + ajjJCm)Cj + j k>j c ajjkC,Ck] (47) We think that these variations and entanglements must be interpreted in the light of theoretical considerations, as follows.…”