Investigation of (micro-)meteoritic materials at the new hard X-ray imaging PUMA beamline for heritage sciences

Abstract

At the French synchrotron facility SOLEIL, a new X-ray imaging facility PUMA (Photons Utilisé s pour les Maté riaux Anciens) has been made available to scientific communities studying materials from cultural heritage. This new instrument aims to achieve 2D and 3D imaging with microscopic resolution, applying different analytical techniques including X-ray fluorescence spectroscopy (XRF), X-ray absorption spectroscopy (XAS), X-ray diffraction and phase-contrast imaging. In order to discover its capabilities a detailed analytical characterization of this beamline as an analytical and imaging tool is deemed necessary. In this work, (confocal) XRF and XAS analyses are demonstrated using the Seymchan pallasite meteorite and an Antarctic unmelted micrometeorite as case studies. The obtained spatial resolution (2 mm  3 mm) and sensitivity (detection limits <10 p.p.m. for 1 s acquisition at 18 keV) show that PUMA is a competitive state-of-the-art beamline, providing several high-profile and high-in-demand analytical methods while maintaining applicability towards a wide range of heritage-oriented sciences.

Synchrotron X-ray Microprobes: An Application on Ancient Ceramics

“…Figure 5 shows the Zn XRF maps in all three samples and the obtained distribution of ZnAl 2 O 4 phase, shown in red in panels a, b and c, respectively. The last image was obtained by differential imaging evaluating the ratios between different peaks identified from reference standards spectra (Figure S4), as successfully used in [44]. In particular we evaluated the ratios between the peaks 3 to 2, 3 to 1 and 2 to 1, which turned out to be bigger than one for the first two ratios and very close to one for the last one, confirming ZnAl 2 O 4 phase on the surface.…”

X-ray irradiation effects on Egyptian blue and green pigments

“…The exposed powder was irradiated at 45° with a beam intensity of I 1 = 1.1 × 10 12 ph s −1 , which corresponds to a flux ph s −1 mm −2 in the first session and a beam intensity of I 2 = 6.3 × 10 11 ph s −1 , corresponding to a flux Φ 2 = 3.2 × 10 10 ph s −1 mm −2 in the second session. More details about the beamline can be found in Tack et al 45 Temperature ( T ) and relative humidity (RH) in the hutch were monitored once a day ( T = 21.3 ° C ± 0.4; RH = 43.1% ± 7.6). Pressure was considered equal to atmospheric pressure (1 atm).…”

“…45 Temperature (T) and relative humidity (RH) in the hutch were monitored once a day (T ¼ 21.3 C AE 0.4; RH ¼ 43.1% AE 7.6).…”

X-ray Fluorescence Spectroscopy of Picrolite Raw Material on Cyprus

“…A cylindrically shaped aluminium collimator with 8 mm internal diameter and 10 mm length was used to reduce the spectral contribution of background scattering and unwanted signals from the sample environment. Detection limits of 0.1-100 ppm for a 1 s measurement time and elements with an atomic number between 17 and 83 were obtained for geological, biological and glass sample matrices [23].…”

“…XRF cartographies were performed on an area typically of 1 mm 2 with 10 µm resolution and an acquisition time of 1 s using the so-called flyscan routine, in which the sample is moved continuously through the beam at a given speed and spectra are acquired over set time intervals, and were corrected for their encoder motor positions before visualisation of the data (see also [23]). The raw data are provided in Supplement Table S2.…”