Increasing the sensitivity of micro X-ray fluorescence spectroscopy through an optimized adaptation of polycapillary lenses to a liquid metal jet source

Abstract

The combination of brilliant liquid metal jet sources (LMJS) and polycapillary lenses yields substantial advantages in the excitation efficiency of traces of transition metals by micro-X-ray fluorescence spectroscopy (µXRF) and...

Quantification routines for full 3D elemental distributions of homogeneous and layered samples obtained with laboratory confocal micro XRF spectrometers

“…To calibrate the parameters of the excitation lens, a software called Polytrans was used, see detailed description in Bauer et al 20 Briefly, the Sherman equation, with a calculated X-ray tube spectrum based on an formalism developed by Ebel 32 in the used geometry and the transmission function of the excitation lens approximated by a Gumbel distribution, is used to simulate the measured MXRF data on thick one element standards. The parameters of the Gumbel distribution are the fitting parameters which are optimized for a best match between calculation and measurement.…”

“…with the index E and D for excitation and detection, s EjD the spot size, w EjD as the angle of excitationjdetection, U the solid angle and T EjD the transmission of the used optical lenses. From previous empirical investigations 7,20 it is well known that the shape of the spot size and transmission functions can be described by analytical functions with a limited number of free parameters. Here, the spot sizes s EjD of the used optics are approximated with a decaying exponential function of the form…”

“…Both, the integral sensitivity η i and the probing volume size σ i are functions of the excitation E 0 and fluorescence energy E i :with the index E and D for excitation and detection, σ E|D the spot size, ϑ E|D as the angle of excitation|detection, Ω the solid angle and T E|D the transmission of the used optical lenses. From previous empirical investigations 7,20 it is well known that the shape of the spot size and transmission functions can be described by analytical functions with a limited number of free parameters. Here, the spot sizes σ E|D of the used optics are approximated with a decaying exponential function of the form σ E|D = σ MAX E|D exp( σ EXP E|D E 0| i ) + σ OFF E|D with σ MAX E|D the maximum spot size, σ EXP E|D the exponential factor of the exponential decay and σ OFF E|D the offset, resp.…”

Atomic spectrometry update: review of advances in X-ray fluorescence spectrometry and its special applications

“…A major improvement of sensitivities achievable in laboratory μXRF spectrometry and for confocal μXRF spectrometers was based 17 on the use of polycapillary lenses specifically adapted to a high-brilliance liquid-metal jet source (LMJS). The LMJS had an effective minimal electron-source spot-size of 15 × 15 μm.…”

Efficient and robust image registration for two-dimensional micro-X-ray fluorescence measurements

“…5 Approaches focus on providing higher brilliance of the X-ray spot by using either alternative sources, like a liquid metal jet X-ray source instead of an X-ray tube, 6 and/or by enhanced focussing optics. 7,8 Another approach is allowing pixels with overlapping spots, i.e. applying the so-called oversampling technique.…”