ARDESIA: A fast silicon drift detector X-ray spectrometer for synchrotron applications

ARDESIA, a four-channel X-ray spectrometer based on silicon drift detectors (SDDs), is presented. It has been developed for synchrotron applications targeting especially X-ray fluorescence (XRF) and X-ray absorption spectroscopy (XAS) with good energy resolution at high count rates (a few Mcps per second). The main target applications are XRF and XAFS techniques. The system features a 2 × 2 monolithic array of 5-mm-pitch SDDs cooled with a double Peltier scheme and coupled to a four-channel CUBE charge preamplifier. Different digital pulse processors allowing operation in Mcps per second count rates are employed. The results of preliminary characterization measurements performed at both the LNF DAΦNE-Light DXR1 beamline and the ESRF LISA BM-08 are reported, in particular, XRF measurements on low atomic number elements (down to the Carbon K-line, 270 eV) and extended X-ray absorption fine structure of trace materials in pyrite.     

Increased zinc accumulation in mineralized osteosarcoma tissue measured by confocal synchrotron radiation micro X‐ray fluorescence analysis

Abnormal tissue levels of certain trace elements such as zinc (Zn) were reported in various types of cancer. Little is known about the role of Zn in osteosarcoma. Using confocal synchrotron radiation micro X‐ray fluorescence analysis, we characterized the spatial distribution of Zn in high‐grade sclerosing osteosarcoma of nine patients (four women/five men; seven knee/one humerus/one femur) following chemotherapy and wide surgical resection. Levels were compared with adjacent normal tissue. Quantitative backscattered electron imaging as well as histological examinations was also performed. On average, the ratio of medians of Zn count rates (normalized to calcium) in mineralized tumor tissue was about six times higher than in normal tissue. There was no difference in Zn levels between tumor fraction areas with a low fraction and a high fraction of mineralized tissue, which were clearly depicted using quantitative backscattered electron imaging. Moreover, we found no correlation between the Zn values and the type of tumor regression according to the Salzer‐Kuntschik grading. The underlying mechanism of Zn accumulation remains unclear. Given the emerging data on the role of trace elements in other types of cancer, our novel results warrant further studies on the role of trace elements in bone cancer. Copyright © 2016 The Authors. X‐Ray Spectrometry published by John Wiley & Sons Ltd.     

硅中掺杂元素砷的三维微分析

利用同步辐射Ｘ光微区分析和全反射Ｘ射线荧光分析技术测定了硅中掺杂元素砷浓度的三维分布，其中深度剖面分布的测定结果与二次离子质谱进行了对照，两的一致性是比较满意的。     

同步辐射X射线荧光光谱国内外研究进展

同步辐射光源是带电粒子在加速器储存环中以接近光速的速度运动时,沿轨道切线方向发射出的辐射,同步辐射X射线荧光分析(SR-XRF)是以同步辐射X射线作为激发光源的X荧光光谱分析技术.同步辐射X射线荧光分析包括了用于微区及微量元素分析的同步辐射XRF、用于表面及薄膜分析的同步辐射全反射X射线荧光(SR-TXRF)以及用于三...     

Irradiation damage to frog inner ear during synchrotron radiation tomographic investigation

Unexpectedly severe radiation damage, showing up through deformation of the saccule, was encountered during a synchrotron radiation high-resolution (700 nm pixel size) tomographic observation of an inner ear, fixed in a formaldehyde solution, of the frog Rana esculenta. The visible displacement of the edge of the otoconia-filled part of the saccule amounted to about 100 μm after an irradiation with 20.5 keV X-ray photons corresponding to a dose of 1.5 kGy for the protein matrix. The close-knit coexistence of organic and mineral components in the biological tissue may be linked to the dramatic increase of radiation dosage sensitivity.     

Characterization of carbonate rocks through X-ray microfluorescence and X-ray computed microtomography

Carbonate rocks play an important role in petroleum geology by acting as reservoir rocks, generators, and even hydrocarbon sealants, accounting for about half of the oil and gas reserves known in the world. The study of these carbonate rocks have become very important in the hydrocarbon exploration scene in Brazil because of they consist in analogous for reservoir rocks of the presalt interval. Thus, the objective of this research was to use X-ray microfluorescence (micro-XRF) and X-ray microtomography analysis, as complementary techniques, in order to characterize samples of carbonate rocks in respect to their structures, textures, mineralogy, and pores. The microtomographic analyses allowed the identification of the horizontal structures as parallel lamination, horizontal, and vertical fractures filled by calcite and biotic constituents (gastropods bioclasts). Different composition of minerals were also identified, as calcite, quartz, feldspars, iron sulfides, and oxides. The porosity (ranges <1 to17%), and the high-density elements could also be quantified, as well as their distribution in each sample. The micro-XRF analysis present a direct relationship with the distribution of minerals that compound carbonate rocks, highlighting some structures, as well as helping to identify trace and minor elements in the carbonates (Mn, Sr, and Mg).     

X-ray microfluorescence with synchrotron radiation applied in the analysis of pigments from ancient Egypt

In this work, X-ray microfluorescence with the synchrotron radiation technique was applied in the analysis of pigments found in decorative paintings in the sarcophagus of an Egyptian mummy. This female mummy, from the Roman Period, which was embalmed with the arms and legs swathed separately is considered one of the most important pieces of the Egyptian Collection from the National Museum (Rio de Janeiro, Brazil). The measurements were performed at the XRF beamline D09B of the Brazilian Synchrotron Light Laboratory (LNLS), using the white beam and a Si(Li) detector with resolution of 165 eV at 5.9 keV. The possible pigments found in the samples were: Egyptian blue, Egyptian green frit, green earth, verdigris, malachite, ochre, realgar, chalk, gypsum, bone white, ivory black and magnetite. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) were applied to the results in order to verify if the samples belong to the same period of a linen wrapping fragment, whose provenance was well established. PACS 07.85.Nc; 07.85.Qe; 78.70.En     

Using the compute unified device architecture programming environment in simulation of ion-beam injection line with account for space charge effect

A simulation of the beam injection line in a synchrotron is performed within the Veksler and Baldin Laboratory of High Energy Physics, Joint Institute for Nuclear Research (VBLHEP JINR), project “The Development and Implementation of Units of a Synchrotron for Hadron Therapy.” The parameters of the injection line are chosen for the transport of beams with intensities of 25–100 mA through the injection channel of the synchrotron with account for the space-charge effect. The simulation was performed using the method of macroparticles (the PIC method). The approach of massively parallel computations on graphics processors using Compute Unified Device Architecture (CUDA) technology was applied for the acceleration of computations. The 66-fold speedup of computations was obtained using the Tesla C1060 computing module instead of a single-core CPU with 2.4 GHz.     

Nondestructive discrimination of small glass fragments for forensic examination using high energy synchrotron radiation x‐ray fluorescence spectrometry

This paper demonstrates that high‐energy SR‐XRF (synchrotron radiation x‐ray fluorescence spectrometry) utilizing 116 keV x‐rays is a powerful technique for nondestructive discrimination of small glass fragments. An XRF spectrum of glass fragments of a standard material SRM612 gave well‐resolved K‐line peaks of 34 elements, including the rare‐earth elements. The relative standard deviations (RSD) of the ratios of the intensities of heavy elements normalized by that of Ba were less than 8.2% for the analyses of 10 fragments (<1 mg) in the energy region above 20 keV. A comparison of glass fragments (<1 mg) obtained from 26 figured glass sheet was performed using elemental intensity ratios that were defined as the intensities of detected elements divided by that of Ba. Analyses of glass fragments revealed the existence of Mo, Pd, Sb, Cs and Bi, and these trace elements could be useful as important indexes to discriminate glass samples. The Ce:Ba ratios could be measured for all the samples with precision of 1.9% and were found to be quite effective parameters for identification of glass fragments, even though these fragments would contain no other characteristic heavy elements. All glass fragments in this study that could not be distinguished on the basis of refractive index (RI) values could be discriminated by this method. Copyright © 2006 John Wiley & Sons, Ltd.     

Luminescence and micro-Raman investigations on inclusions of unusual habit in chrysoprase from Turkey

Chemical analyses performed on chrysoprase from Turkey have shown many trace elements as well as rare earth impurities. Quantitative chemical analyses of inclusions in minerals can improve our understanding of the chemistry of surface. The environmental scanning electron microscope (ESEM) with an attached X-ray energy dispersive system (EDS) is capable of producing rapid and accurate major element chemical analyses of individual inclusions in crystals larger than about 30 μm in diameter. The samples were examined with lifetime-resolved and spatially-resolved cathodoluminescence (CL), and inductively coupled plasma-atomic emission spectrometry (ICP-AES). Spatially resolved CL results at room temperature were recorded for two different areas. Bulk area displays with low CL emission and pores contain iron phases such as chromite, hematite and anatase which cause the green color. For the raw data in the lifetime resolved CL spectrum, at least three broad emission bands were detected in a yellow band of the highest intensity at about 550 nm, a weaker orange band at about 650 nm, and a red band at 720 nm. It is assumed that there are links between the CL emissions and the presence of some transition metal and REE elements, but it is obvious that all trace elements do not play a direct role. Micro-Raman measurements were performed on chrysoprase and these showed a characteristic intensive Raman band peaked at 464 cm^?1 which can be inferred to ν₂ doubly symmetric bending mode of [SiO₄/M] centers. Raman spectrum of all inclusions found in the material are also given and discussed in detail.     

Distribution and incorporation of zinc in biological calcium phosphates

Human dental calculi are biological calcium phosphates, which consist of an organic phase and an inorganic or mineral phase. In the latter phase, spectrochemical analyses have revealed the presence of several different magnesium and calcium phosphates. As the crystalline structure of the calculus passes through several stages during its allocation in the mouth, special attention is paid to some elements, such as zinc, that can modify the mineralization process. Several in vitro studies relating to the dental calculus mineralization process have been performed so far, but there is a lack of data obtained from biologically synthesized samples. The knowledge of the zinc distribution and incorporation in biological calcium phosphates is of great interest in providing more information about the biological process of calculus formation. In this paper we present surveys of the elemental distribution and incorporation of zinc in human dental calculus, by using a combination of different techniques: x‐ray microfluorescence using synchrotron radiation, scanning electron microscopy and x‐ray absorption spectroscopy. One‐dimensional x‐ray microfluorescence of zinc and magnesium measurement shows that there is a high accumulation of both elements in the sub‐gingival region of the calculus and a strong correlation of their spatial distribution. Experimental Ca/P molar ratios were determined by energy‐dispersive spectroscopy to identify different calcium phosphate phases, the sub‐gingival region being composed of a mixture of highly and poorly calcified phosphates and the supra‐gingival region composed mainly of carbonated hydroxyapatite. Finally, x‐ray absorption measurements were carried out at the zinc K edge on synthetic and biological samples. The Zn—O distance and coordination number of the synthetic samples and the supra‐gingival calculus show that zinc is adsorbed on these structures, whereas in the sub‐gingival samples it is allocated in a cation site. The results are indicative of the active participation of zinc in the calcification process of sub‐gingival calculus. Copyright © 2003 John Wiley & Sons, Ltd.     

The validity of commercial LIBS for quantitative analysis of brass alloy — comparison of WDXRF and AAS

Commercial low-cost laser induced breakdown spectroscopy (LIBS) has been successfully employed for the quantitative analysis of a Cu-based alloy using a Nd:YAG laser at 1064 nm. The main aim of the present investigation is to explore the benefits of a commercial low-cost LIBS setup. It was recognized that some trace elements such as Al and S could not be detected by LIBS even with a high-resolution spectrometer. The main difficulties in quantifying Cu as a basic component of a brass alloy are related to the self-absorption of Cu spectral lines, with the effect complicated at Cu concentrations higher than 65%. However, few Cu lines such as that at 330.795 nm would be helpful to use due to their lower susceptibility to self-absorption. LIBS, flame atomic absorption spectrometry (FAAS), and wavelength dispersive X-ray fluorescence (WDXRF) were compared for the detection of major and trace metals in the Cu-based alloy. In the case of WDXRF, the brass samples were identified by using a standardless quantitative analysis program depending on a fundamental parameter approach. The quantitative analysis results were acceptable for most of the major and minor elements of the brass sample. Therefore, commercial low cost LIBS would be useful for quantitative analysis of most elements in different types of alloys.     

Study of monazite under high pressure

Monazite was studied under high pressures of up to 20 GPa and 12 GPa by using synchrotron X-ray diffraction and Raman spectroscopy, respectively. X-ray diffraction data suggested that there was a structural distortion at ～11.5 GPa. The pressure–volume data of the monazite was fitted to a third-order Birch–Murnaghan equation of state and yielded a bulk modulus of 109(1) GPa and a pressure derivative of 6.7(1), in agreement with an empirical formula.     

Determination of trace elements Fe,cu and Zn in the Algerian cancerous plasma using X-ray fluorescence (XRF)

Cancers are among the leading causes of morbidity and mortality in the world. The purpose of this study was to conduct a survey on the effect of minerals on cancer risk in the Algerian population. One hundred and seventy-eight plasma samples were used to analyze the concentrations of iron (Fe), copper (Cu), and zinc (Zn) in cancerous patients and also in healthy subjects using the X-ray florescence technique (XRF). Samples were classified according to the age and gender of the donors. An empirical formula was developed for the concentration of Zinc, Copper and Iron in cancer patients according to the age. The averages iron, copper and zinc concentrations in mg/kg for control and Cancer disease groups were (1493 ± 105; 1496 ± 86), (1172 ± 229; 1078 ± 283) and (1266 ± 202; 1344 ± 208) respectively. The ANOVA One-Way test was applied. For both genders of control and cancer disease groups it shows a significant decrease rate of copper for global and female gender and a significant increase rate of zinc for global and male gender (p < 0.05). The results indicate that the Cu and Zn concentration could show helpful tools for diagnosis and preventive treatment of cancer diseases.     

Behavior of copper under high pressure: Experimental and theoretical analyses

The physical properties of high-purity copper under high pressure were investigated with X-ray diffraction(XRD) using the 3rd generation synchrotron radiation and a diamond anvil cell(DAC) and First-principles calculation using ab-initio simulation program. And they differ 15 % from those reported in the past. The previously reported experimental isothermal bulk moduli for polycrystalline copper and single crystalline copper are 140.2 ± 3.9 GP and 137.6 ± 0.2 GPa respectively, and the theoretical isothermal bulk modulus of copper is 134.6 GPa [1–20]. However, the recently measured bulk moduli of copper are 120.8 ± 4.4 GPa for polycrystal and 120.7 ± 2.1 GPa for single crystal respectively. The difference might mainly come from the purity of copper owing to the development of scientific technology, and the 3-dimensional effect of defects in nearly pure(perfect) crystalline materials was first observed by using DAC and XRD.     

Some practical considerations about the effects of radiation damage on hydrated cells imaged by X-ray fluorescence microscopy

X-ray fluorescence (XRF) microscopy features unique capabilities which make it well suited for biological investigations. Its high sensitivity together with high spatial resolution and penetration depth provide a unique tool for trace elements analysis in heterogeneous samples. Like most of the X-ray based techniques, radiation damage sets hard limits on the ultimate performance. Although the interactions between matter and photons are well described from a physics point-of-view, there is a lack of experimental data, in particular for XRF imaging mode. In this context, this work proposes a practical approach in addressing the limits set by radiation damage to X-ray fluorescence imaging in the case of hydrated and unfixed cells at room temperature. We find that the maximum dose tolerated by ascidian blood cells is 10⁵ Gy. A simple theoretical model allowed the minimal doses required for a good image contrast to be determined for various experimental schemes. The results are consistent with the experimental observation on ascidian blood cells which exemplifies the peculiar case of highly concentrated samples (>10,000 ppm) at room temperature. The same simple model predicts that in the case of the detection of high Z trace elements in cryo-preserved cells, the relative detection limit set by radiation damage is below 0.1 ppm at a spatial resolution of 100 nm.     

Synchrotron-based X-ray fluorescence,imaging and elemental mapping from biological samples

The present study utilized the new hard X-ray microspectroscopy beamline facility, X27A, available at NSLS, BNL, USA, for elemental mapping. This facility provided the primary beam in a small spot of the order of ∼10 μm, for focussing. With this spatial resolution and high flux throughput, the synchrotron-based X-ray fluorescent intensities for Mn, Fe, Zn, Cr, Ti and Cu were measured using a liquid-nitrogen-cooled 13-element energy-dispersive high-purity germanium detector. The sample is scanned in a ‘step-and-repeat’ mode for fast elemental mapping measurements and generated elemental maps at 8, 10 and 12 keV, from a small animal shell (snail). The accumulated trace elements, from these biological samples, in small areas have been identified. Analysis of the small areas will be better suited to establish the physiology of metals in specific structures like small animal shell and the distribution of other elements.     

Chemical state analysis of heat-treated polyacrylonitrile fiber using soft X-ray spectromicroscopy

Chemical state analyses of heat-treated polyacrylonitrile (PAN) fibers with a spatial resolution of 200 nm have been performed using scanning transmission X-ray microscopy (STXM) at a third generation synchrotron radiation facility. Near-edge X-ray absorption fine structure (NEXAFS) spectra and chemical state images have been obtained on the cross-sectioned fiber specimens. A clear `core–rim' structure has been observed in the heat-treated fibers. The spectral characteristics show that the fiber has less nitrile group in the core region, suggesting that, contrary to the model widely believed, the conversion of the nitrile to other chemical species proceeds faster in the core of the fibers.     

In-line X-ray lensless imaging with lithium fluoride film detectors

In this work, we present preliminary in-line X-ray lensless projection imaging results at a synchrotron facility by using novel solid-state detectors based on non-destructive readout of photoluminescent colour centres in lithium fluoride thin films. The peculiarities of LiF radiation detectors are high spatial resolution on a large field of view, wide dynamic range, versatility and simplicity of use. These properties offered the opportunity to test a broadband X-ray synchrotron source for lensless projection imaging experiments at the TopoTomo beamline of the ANKA synchrotron facility by using a white beam spectrum (3–40 keV). Edge-enhancement effects were observed for the first time on a test object; they are discussed and compared with simulations, on the basis of the colour centre photoluminescence linear response found in the investigated irradiation conditions.     

Radiation damage in soft X-ray microscopy

The rates of chemical transformation by radiation damage of polystyrene (PS), poly(methyl methacrylate) (PMMA), and fibrinogen (Fg) in a X-ray photoemission electron microscope (X-PEEM) and in a scanning transmission X-ray microscope (STXM) have been measured quantitatively using synchrotron radiation. As part of the method of dose evaluation in X-PEEM, the characteristic (1/e) sampling depth of X-PEEM for polystyrene in the C 1s region was measured to be 4 ± 1 nm. Critical doses for chemical change as monitored by changes in the X-ray absorption spectra are 80 (12), 280 (40) and 1230 (180) MGy (1 MGy = 6.242*ρ eV/nm³, where ρ is the polymer density in g/cm³) at 300 eV photon energy for PMMA, Fg and PS, respectively. The critical dose for each material is comparable in X-PEEM and STXM and the values cited are thus the mean of the values determined by X-PEEM and STXM. C 1s, N 1s and O 1s spectroscopy of the damaged materials is used to gain insight into the chemical changes that soft X-rays induce in these materials.