Current trends in the literature on x‐ray emission spectrometry

Abstract

Based on a computerized literature search through Chemical Abstracts for the period 1968–89 and on a manual search through Analytical Abstracts for 1988, trends in the literature are discussed for x‐ray emission spectrometry in general, and for x‐ray fluorescence analysis, proton‐induced x‐ray emission and synchrotron‐induced x‐ray fluorescence analysis. Relative contributions are derived for articles dealing with various excitation and detection modes, with different application fields and from different countries. Special attention is paid toenvironmental applications of x‐ray emission spectrometry.

Determination of contrast media administration to achieve a targeted contrast enhancement in computed tomography

“…[13][14][15][16] The iterative deconvolution technique assumes that the final target response is composed of the individual responses of a series of unit signals (strips). In this method, the reference response was calculated by applying our forward compartmental model to the first unity signal strip (input function).…”

Optimizing detector geometry for trace element mapping by X-ray fluorescence

“…In order to do that, one needs to have reliable approximations of the background to estimate the signal above the background. When dealing with real spectra from the experiment, one can use non-iterative background approximation methods like the three-window method [43, p. 397], interpolation, and polynomial fitting [44]. One may also use iterative methods like simple multiple-point smoothing [45], or more sophisticated ones like the Statistics-sensitive Non-linear Iterative Peak-clipping (SNIP) algorithm [46].…”

“…We assume that photons incident on the detector are filtered with a 24 μ m thick Be window, as is typically installed. Perfect spectral lines in the calculated theoretical spectra are then convolved with the detector response function, where we will use the same notation as [44]. The detector response is described by a modified Gaussian function of $$P(E_i,E_j)=G(E_i,E_j)+f_{S}S(E_i,E_j)+f_{T}T(E_i,E_j),$$ where $$G(E_i,E_j)=\frac{\text{GAIN}}{s\sqrt{2\pi }}\exp true[-\frac{{(E_j-E_i)}^2}{2s^2}true]$$ is the Gaussian function which describes the broadening of the peak due to limited energy resolution of the detector.…”

“…GAIN is the detector channel gain in eV/channel, E j the energy (in eV) of the X-ray line, and E i the energy (in eV) of the i th channel of the detector. The peak width s is given by $$s^2={\left(\frac{\text{NOISE}}{2.3548}\right)}^2+3.58\mathrm{FANO}{E}_j$$ where NOISE is the electronic contribution to the peak width (typically 80 - 100 eV FWHM) with the factor $2\sqrt{2\ln 2}\approx 2.3548$ converting FWHM to σ ; FANO is the Fano factor (~ 0.114), and 3.58 is the energy (in eV) required to produce an electron-hole pair in silicon [44, p. 282]. The factors f S = 0.03 and f T = 0.02 describe the fractions of photon intensities that arrive in the step and the tail, respectively (Figure 6), and again these values are for silicon [44, p. 282].…”

On the 40th anniversary of the journal X‐Ray Spectrometry

“…The authors of these review papers are the known American specialists H. A. Liebhafsky, E. H. Winslow, and H. Pfeiffer (1960 and 1962), W. J. Campbell and J. D. Brown (1964), W. J. Campbell, J. D. Brown, and J. W. Thatcher (1966 and 1968), W. J. Campbell and J. V. Gilfrich (1970), L. S. Birks (1972), and L. S. Birks and J. V. Gilfrich (1974 and 1976) . Figure presents data of the annual number of publications on X‐ray spectral analysis . The total number of papers on X‐ray spectral analysis in 1971 (before the publication of the first issue of X‐Ray Spectrometry ) was about 200.…”