Design of Tender X-ray Absorption Spectroscopy Beamline in Taiwan Photon Source

Abstract

A new tender X-ray absorption spectroscopy beamline for operating over the photon energy range from 1.7 keV to 11 keV is under construction at port 32 of the Taiwan Photon Source (TPS). The TPS 32A beamline uses two back-to-back water-cooled double crystal monochromators (DCMs), InSb(111) and Si(111), for achieving the wide energy tunability. The beamline design takes advantage of the low emittance of the TPS accelerator and a bending magnet (BM) to obtain a high-brightness focussed beam. In order to overcome the issue of poor thermal conductivity of InSb(111) crystals while facing high thermal load, we have implemented the following features : (i) we have controlled the flux and heat load by optimizing the source collection angle of 2 × 0.15 mrad2 (h × v), and (ii) we have installed water cooled double-bounce high harmonic rejection mirrors (HHRMs) with a variable incidence angle upstream of the DCM to reduce the heat load on the first InSb crystal. The DCM is followed by a 2:1 toroidal focusing mirror (TFM) which focuses the beam parallel to the floor of the experimental endstation. The simulated focus beam size is 0.9 × 0.9 mm2 (h × v, FWHM) using the InSb(111) DCM at 1.7 keV, and 0.2 × 0.45 mm2 (h × v, FWHM) using the Si(111) DCM at 4 keV, respectively. The photon flux is 1010 -1012 photons s−1 in the energy range of 1.7 to 11 keV at the sample stage after passing through the Be windows. The design parameters of photon flux and beam spot size will facilitate a tender X-ray source for carrying out high-quality X-ray absorption spectroscopy experiments.

X-ray Absorption Spectroscopy as a Process Analytical Technology: Reaction Studies for the Manufacture of Sulfonate-Stabilized Calcium Carbonate Particles

“…This has limited the use of XAS on industrial systems and hence its consideration as a PAT tool. The past decade has seen significant steps toward the expansion of XAS provision at national synchrotron facilities all over the world, accessible both for fundamental and applied research, so that XAS is now in many fields, e.g., catalysis, considered part of the standard analytical toolkit. − Moreover, XAS systems using laboratory X-ray sources are now readily available at a price point comparable to XRD, thus opening a realistic perspective to a wider use of XAS in applied manufacturing research. − Wide application of these laboratory-based instruments to complex industrially relevant systems is currently limited by low energy resolution, low signal-to-noise ratio, and extended data acquisition times. However, recent studies show promising in situ and operando results that highlight the complementary aspects of laboratory and synchrotron XAS. , …”