Tomographic absorption spectroscopy for the study of gas dynamics and reactive flows

This review describes advances in the XRF group of techniques published approximately between April 2015 and March 2016. Fundamental contributions in the instrumentation sections include the development of synchrotron radiation sources, semiconductor design technology and evaluating the quality of in situ hand-held XRF results. A bench top TXRF spectrometer for the measurement of the elements from carbon to uranium is described that offers achievable detection limits that range from ng g−1 to μg g−1. The applications sections aim to give a representative overview of the range of applications that use XRF techniques with an emphasis on papers that describe technical or application innovation. Sample size investigated ranged from the planet Mercury down to nano-gram quantities of cement secreted by settlement stage barnacle larvae. The archaeological and cultural heritage section this year includes an authentic report on the use of cannabis as a filler in ancient lime plaster and heartening news that the construction of an underground parking garage in the centre of Zurich (Switzerland) unearthed the remains of seven Neolithic settlements from the 4th and 3rd millennium BC. The X-ray excitation of iron present in ancient iron-gall inks was presented as a step toward the non-invasive reading of fragile and/or unopenable documents. Feedback from readers of this review is most welcome and the review coordinator may be contacted using the email address provided.

https://pubs.rsc.org/en/content/articlepdf/2021/ja/d1ja90033a

2016 Atomic Spectrometry Update – a review of advances in X-ray fluorescence spectrometry and its applications

Mobile instrumentation is of growing importance to archaeometry research. Equipment is utilized in the field or at museums, thus avoiding transportation or risk of damage to valuable artifacts. Many spectroscopic techniques are nondestructive and micro-destructive in nature, which preserves the cultural heritage objects themselves. This review includes over 160 references pertaining to the use of mobile spectroscopy for archaeometry. Following a discussion of terminology related to mobile instrumental methods, results of a literature survey on their applications for cultural heritage objects is presented. Sections devoted to specific techniques are then provided: Raman spectroscopy, X-ray fluorescence spectrometry, Fourier transform infrared spectroscopy, laser-induced breakdown spectroscopy, and less frequently used techniques. The review closes with a discussion of combined instrumental approaches.

https://journals.sagepub.com/doi/pdf/10.1177/0003702815611063

Mobile Spectroscopic Instrumentation in Archaeometry Research.

In this work we investigate the strongly inhomogeneous distribution of CO2 and H2O in a synthetic beryl having a peculiar hourglass zoning of Cr due to the crystal growth. The sample was treated at 800°C, 500 MPa, in a CO2-rich atmosphere. High-resolution FESEM images revealed that the hourglass boundary is not correlated to physical discontinuities, at least at the scale of tens of nanometers. Polarized FPA-FTIR imaging, on the other side, revealed that the chemical zoning acts as a fast pathway for carbon dioxide diffusion, a feature never observed so far in minerals. The hourglass zone boundary may be thus considered as a structural defect possibly due to the mismatch induced by the different growth rates of each sector. High-resolution synchrotron-light FTIR imaging, in addition, also allows enhancement of CO2 diffusion along the hourglass boundary to be distinguished from diffusion along fractures in the grain. Therefore, FTIR imaging provides evidence that different diffusion mechanisms may locally combine, suggesting that the distribution of the target molecules needs to be be carefully characterized in experimental studies. This piece of information is mandatory when the study is aimed at extracting diffusion coefficients from analytical profiles. Combination of TOF-SIMS and FPA data shows a significant depletion of type II H2O along the hourglass boundary, indicating that water diffusion could be controlled by the distribution of alkali cations within channels, coupled to a plug effect of CO2.

/pdf/ftir-imaging-in-diffusion-studies-co2-and-h2o-in-a-synthetic-1phdbzifw9.pdf

FTIR imaging in diffusion studies: CO2 and H2O in a synthetic sector-zoned beryl

This review describes advances in the continued expansion of work using the XRF group of techniques published approximately between April 2013 and March 2014. Specialised laboratory instrumentation, X-ray sources, detector development and data processing continue unabated. It is remarkable how quickly hand-held XRF instrumentation has developed to the point where many examples of its use are included in the various application sections of this review, rather than in the instrumentation section. Several new beam lines and their new end-stations were described in publications from SR research centres around the world. More analysts are attracted to TXRF and related techniques with new sample preparation techniques offered for an expanding range of applications. Nanoparticles and nanomaterials feature throughout this review particularly in clinical, biological and environmental studies. A novel approach for the reuse of industrial by-products described how acid mine drainage sludge and coal fly ash facilitated the problem of the high levels of phosphate present in waste waters (cow dung) from the dairy industry. The archaeological and cultural heritage section often includes good news stories. This year we learn how an XRF mapping technique was used to show that Pablo Picasso used a popular brand of French house paint in his works of art.

2014 Atomic Spectrometry Update – a review of advances in X-ray fluorescence spectrometry

X-ray fluorescence investigation of gilded and enamelled silver: The case study of four medieval processional crosses from central Italy

GDI spray structure analysis by polycapillary X-ray μ-tomography

Laboratory total reflection X-ray fluorescence analysis for low concentration samples ☆

Application of polycapillary optical systems to improve a spatial resolution for the μ-XRF analysis by focusing a primary x-ray beam and/or by collecting fluorescence emission is well known. The challenge is to optimize them in combination with x-ray source for exciting K-lines above 20 keV that could allow characterization of many materials composed by heavy elements. To pursue this goal, preliminary studies on possible polycapillary lens employment in thickness determination for multilayer metal materials will be presented in this work. In this paper, the results of first attempts of integrating PyMCA with Monte Carlo simulation code (XMI-MSIM) that takes into account the secondary fluorescence effects on quantitative analysis of homogeneous matrices, in particular, metal alloys, are presented.

Experimental study for the feasibility of using hard x-rays for micro-XRF analysis of multilayered metals

Recently opened for users at LNF XLab-Frascati a μ XRF station, named “Rainbow X-ray” – RXR, has been optimized for most of X-ray analytical research fields. The basic principle of the station is in the use of various geometrical combinations of polycapillary optics for X-ray beam shaping (focusing/collimation) at specially designed laboratory unit. In this work we have presented the results of archaeological studies on the artifacts of Paleolithic period and Iron Age (9th century BC to the midway of the 8th BC). The elemental analysis of these artifacts has been first performed by compact laboratory setup. Superficial (2D) and bulk (3D) micro-fluorescence mapping provides useful informations for the geologists in order to identify the possible artifacts provenience and origin. The results presented in this work are a part of wider anthropological/archeological investigations aimed at the understanding of social and economical relations of prehistorical communities.

C. Polese

Papers

X-ray fluorescence investigation of gilded and enamelled silver: The case study of four medieval processional crosses from central Italy

GDI spray structure analysis by polycapillary X-ray μ-tomography

Laboratory total reflection X-ray fluorescence analysis for low concentration samples ☆

Experimental study for the feasibility of using hard x-rays for micro-XRF analysis of multilayered metals

2D-3D μXRF elemental mapping of archeological samples