scholarly journals Fifteen Years of Radionuclide Research at the KIT Synchrotron Source in the Context of the Nuclear Waste Disposal Safety Case

Geosciences ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 91 ◽  
Author(s):  
Jörg Rothe ◽  
Marcus Altmaier ◽  
Ron Dagan ◽  
Kathy Dardenne ◽  
David Fellhauer ◽  
...  
Keyword(s):  
X Ray Diffraction ◽  
Radionuclide Studies ◽  
Synchrotron Source ◽  
X Ray ◽  
Safety Case ◽  
Material Sciences ◽  
The 19Th Century ◽  
Analytical Tools ◽  
X Ray Absorption ◽  
Analytical Power

For more than 120 years, systematic studies of X-ray interaction with matter have been the basis for our understanding of materials—both of natural or man-made origin—and their structure-function relationships. Beginning with simple radiographic imaging at the end of the 19th century, X-ray based analytical tools such as X-ray diffraction, X-ray fluorescence and photoemission or X-ray absorption techniques are indispensable in almost any field of chemical and material sciences—including basic and applied actinide and radionuclide studies. The advent of dedicated synchrotron radiation (SR) sources in the second half of the last century has revolutionized the analytical power of X-ray probes, while—with increasing number of SR facilities—beamline instrumentation followed a trend towards increasing specialization and adaption to a major research topic. The INE-Beamline and ACT station at the KIT synchrotron source belong to the exclusive club of a few synchrotron beamline facilities—mostly located in Europe—dedicated to the investigation of highly radioactive materials. Since commissioning of the INE-Beamline in 2005, capabilities for synchrotron-based radionuclide and actinide sciences at KIT have been continuously expanded, driven by in-house research programs and external user needs.

MARS, A New Facility for X-ray Diffraction and X-ray Absorption for Radioactive Matter Studies

2010 ◽  
Vol 1264 ◽  
Author(s):  
Sandrine Schlutig ◽  
Pier Lorenzo Solari ◽  
Hervé Hermange ◽  
Bruno Sitaud
Keyword(s):  
Absorption Spectroscopy ◽  
First Year ◽  
X Ray Diffraction ◽  
Standard Equipment ◽  
X Ray ◽  
Technical Specifications ◽  
Analytical Tools ◽  
X Ray Absorption ◽  
New Facility

AbstractThe MARS (Multi-Analyses on Radioactive Samples) beamline, at Synchrotron Soleil (France) is fully dedicated to advanced structural and chemical characterizations of radioactive matter (solid or liquid), coupling analytical tools such as X-ray absorption spectroscopy, X-ray diffraction, X-ray fluorescence and associated micro-beam techniques. This beamline is now partially operational and has completed its first year of working with samples below exemption limits. This paper describes the beamline design and its technical specifications as well as the standard equipment of the experimental stations and the first obtained results.

X-Ray absorption edge elemental imaging of B. thuringienis

1989 ◽  
Vol 47 ◽  
pp. 212-213
Author(s):  
R. L. Stears
Keyword(s):  
Absorption Edge ◽  
Elemental Distribution ◽  
X Rays ◽  
Differential Absorption ◽  
Synchrotron Source ◽  
High Brightness ◽  
X Ray ◽  
Elemental Imaging ◽  
Cellular Integrity ◽  
X Ray Absorption

Because of the nature of the bacterial endospore, little work has been done on analyzing their elemental distribution and composition in the intact, living, hydrated state. The majority of the qualitative analysis entailed intensive disruption and processing of the endospores, which effects their cellular integrity and composition.Absorption edge imaging permits elemental analysis of hydrated, unstained specimens at high resolution. By taking advantage of differential absorption of x-ray photons in regions of varying elemental composition, and using a high brightness, tuneable synchrotron source to obtain monochromatic x-rays, contact x-ray micrographs can be made of unfixed, intact endospores that reveal sites of elemental localization. This study presents new data demonstrating the application of x-ray absorption edge imaging to produce elemental information about nitrogen (N) and calcium (Ca) localization using Bacillus thuringiensis as the test specimen.

Texture of submicron Ni-Mn-Ga films studied by X-ray diffraction at the ANKA synchrotron source

2007 ◽  
Vol 2007 (suppl_26) ◽  
pp. 229-234 ◽  
Author(s):  
V. A. Chernenko ◽  
S. Doyle ◽  
M. Kohl ◽  
P. Müllner ◽  
S. Besseghini ◽  
...  
Keyword(s):  
X Ray Diffraction ◽  
Synchrotron Source ◽  
X Ray

Local atomic structure in tetragonal pure ZrO2nanopowders

2010 ◽  
Vol 43 (2) ◽  
pp. 227-236 ◽  
Author(s):  
Leandro M. Acuña ◽  
Diego G. Lamas ◽  
Rodolfo O. Fuentes ◽  
Ismael O. Fábregas ◽  
Márcia C. A. Fantini ◽  
...  
Keyword(s):  
Tetragonal Phase ◽  
Local Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Structures ◽  
Crystallite Sizes ◽  
Exafs Study ◽  
The Difference ◽  
X Ray Absorption ◽  
Good Agreement

The local atomic structures around the Zr atom of pure (undoped) ZrO2nanopowders with different average crystallite sizes, ranging from 7 to 40 nm, have been investigated. The nanopowders were synthesized by different wet-chemical routes, but all exhibit the high-temperature tetragonal phase stabilized at room temperature, as established by synchrotron radiation X-ray diffraction. The extended X-ray absorption fine structure (EXAFS) technique was applied to analyze the local structure around the Zr atoms. Several authors have studied this system using the EXAFS technique without obtaining a good agreement between crystallographic and EXAFS data. In this work, it is shown that the local structure of ZrO2nanopowders can be described by a model consisting of two oxygen subshells (4 + 4 atoms) with different Zr—O distances, in agreement with those independently determined by X-ray diffraction. However, the EXAFS study shows that the second oxygen subshell exhibits a Debye–Waller (DW) parameter much higher than that of the first oxygen subshell, a result that cannot be explained by the crystallographic model accepted for the tetragonal phase of zirconia-based materials. However, as proposed by other authors, the difference in the DW parameters between the two oxygen subshells around the Zr atoms can be explained by the existence of oxygen displacements perpendicular to thezdirection; these mainly affect the second oxygen subshell because of the directional character of the EXAFS DW parameter, in contradiction to the crystallographic value. It is also established that this model is similar to another model having three oxygen subshells, with a 4 + 2 + 2 distribution of atoms, with only one DW parameter for all oxygen subshells. Both models are in good agreement with the crystal structure determined by X-ray diffraction experiments.

The Relative Merits of Oxides of Hafnium, Cerium and Thorium as Surrogates for Plutonium Oxide in Calcium Phosphate Ceramics

2009 ◽  
Vol 1193 ◽  
Author(s):  
B. L. Metcalfe ◽  
S. K. Fong ◽  
L. A. Gerrard ◽  
I. W. Donald ◽  
E. S. Welch ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Calcination Temperature ◽  
Cerium Oxide ◽  
Absorption Spectroscopy ◽  
Hafnium Oxide ◽  
Intermediate Level ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Absorption ◽  
Additional Phase

AbstractThe choice of surrogate for plutonium oxide for use during the initial stages of research into the immobilization of intermediate level pyrochemical wastes containing plutonium andamericium oxides in a calcium phosphate host has been investigated by powder X-ray diffraction and X-ray absorption spectroscopy. Two non-radioactive surrogates, hafnium oxide and cerium oxide, together with radioactive thorium oxide were compared. Similarities in behaviour were observed for all three surrogates when calcined at the lowest temperature, 750°C but differences became more pronounced as the calcination temperature was increased to 950°C. Although some reaction occurred between all the surrogates and the host to form a substituted whitlockite phase, increasing the temperature led to a significant increase in the cerium reaction and the formation of an additional phase, monazite. Additionally it was observed that the cerium became increasingly trivalent at higher temperatures.

LiMn2-xCuxO4 Spineis - 5 V Cathode Materials

1997 ◽  
Vol 496 ◽  
Author(s):  
Yair Ein-Eli ◽  
W. F. Howard ◽  
Sharon H. Lu ◽  
Sanjeev Mukerjee ◽  
James McBreen ◽  
...  
Keyword(s):  
Copper Ions ◽  
Oxide Phase ◽  
Electrochemical Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spinel Compounds ◽  
Composition And Structure ◽  
Phase Spinel ◽  
Lithium Copper Oxide ◽  
X Ray Absorption

ABSTRACTA series of electroactive spinel compounds, LiMn2-xCuxO4 (0.1 ≤ x ≤ 0.5) has been studied by crystallographic, spectroscopie and electrochemical methods and by electron-microscopy. These LiMn2-xCuxO4 spinels are nearly identical in structure to cubic LiMn2O4 and successfully undergo reversible Li intercalation. The electrochemical data show slight shifts to higher voltage for the delithiation reaction that normally occurs at 4.1 V in standard Li1−xMn2O4 electrodes (1 ≥ x ≥ 0) corresponding to the oxidation of Mn3+ to Mn4+. The data also show a remarkable reversible electrochemical process at 4.9 V which is attributed to the oxidation of Cu2+ to Cu3+. The inclusion of Cu in the spinel structure enhances the electrochemical stability of these materials upon cycling. The initial capacity of LiMn2-xCuxO4 spinels decreases with increasing x from 130 mAh/g in LiMn2O4 (x=0) to 70 mAh/g in “LiMn1.5Cu0.5O4”(x=0.5). Although the powder X-ray diffraction pattern of “LiMn1.5Cu0.5 O4” shows a single-phase spinel product, neutron diffraction data show a small, but significant quantity of an impurity phase, the composition and structure of which could not be identified. X-ray absorption spectroscopy was used to gather information about the oxidation states of the manganese and copper ions. The composition of the spinel component in the LiMn1.5Cu0.5O4 was determined from X-ray diffraction and XANES data to be Li1.01Mn1.67Cu0.32O4 suggesting, to a best approximation, that the impurity in the sample was a lithium-copper-oxide phase.

scholarly journals Structural Evolution in Wet Mechanically Alloyed Co-Fe-(Ta,W)-B Alloys

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 800
Author(s):  
Vladimír Girman ◽  
Maksym Lisnichuk ◽  
Daria Yudina ◽  
Miloš Matvija ◽  
Pavol Sovák ◽  
...  
Keyword(s):  
Structural Changes ◽  
Magnetic Measurements ◽  
Structural Evolution ◽  
High Energy ◽  
Control Agent ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
X Ray ◽  
Transmission Electron ◽  
X Ray Absorption

In the present study, the effect of wet mechanical alloying (MA) on the glass-forming ability (GFA) of Co43Fe20X5.5B31.5 (X = Ta, W) alloys was studied. The structural evolution during MA was investigated using high-energy X-ray diffraction, X-ray absorption spectroscopy, high-resolution transmission electron microscopy and magnetic measurements. Pair distribution function and extended X-ray absorption fine structure spectroscopy were used to characterize local atomic structure at various stages of MA. Besides structural changes, the magnetic properties of both compositions were investigated employing a vibrating sample magnetometer and thermomagnetic measurements. It was shown that using hexane as a process control agent during wet MA resulted in the formation of fully amorphous Co-Fe-Ta-B powder material at a shorter milling time (100 h) as compared to dry MA. It has also been shown that substituting Ta with W effectively suppresses GFA. After 100 h of MA of Co-Fe-W-B mixture, a nanocomposite material consisting of amorphous and nanocrystalline bcc-W phase was synthesized.

scholarly journals Synthesis, Crystal Structure and Magnetic Properties of Bixbyite-type Vanadium Oxide Nitrides

2009 ◽  
Vol 64 (3) ◽  
pp. 281-286 ◽  
Author(s):  
Suliman Nakhal ◽  
Wilfried Hermes ◽  
Thorsten Ressler ◽  
Rainer Pöttgen ◽  
Martin Lerch
Keyword(s):  
Crystal Structure ◽  
Vanadium Oxide ◽  
Magnetic Ordering ◽  
Vanadium Oxides ◽  
Detectable Amount ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vanadium Sulfide ◽  
Structure Result ◽  
X Ray Absorption

Ammonolysis of vanadium sulfide leads to the formation of bixbyite-type vanadium oxide nitrides. Small amounts of nitrogen incorporated in the structure result in the stabilization of the bixbyite type not known for vanadium oxides. The crystal structure was investigated using X-ray diffraction and X-ray absorption spectroscopy. At temperatures above 550 °C the powders decompose to corundumtype V2O3 containing no detectable amount of nitrogen. Below 39 K magnetic ordering is observed.

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