In 8-to 20-keV photon energy region, ruthenium and carbon thin films are used in multilayer monochromators. In the present study, this material combination is explored for X-ray waveguide applications in hard X-ray region. The structural parameters (thickness of each layer) of Ru/C/Ru waveguide structure are optimized to get maximum intensity enhancement of fundamental mode inside carbon guiding layer. A sample with optimized structural parameters is deposited using ion beam sputtering (IBS) technique and characterized using X-ray reflectivity (XRR) and grazing incidence X-ray fluorescence (GIXRF) techniques. The analysis suggests that the density of bottom Ru layer and carbon guiding layer is close to bulk density ($97% for Ru and $95% for carbon), whereas density of top Ru layer is slightly lower ($93% of bulk density). A $10% of thickness variation in top cladding layer along with marginal change in layer density deteriorate field enhancement in TE 0 mode by more than three times. Effect of thickness and density variation on waveguide (Ru [7 nm]/C [18 nm]/Ru [20 nm]) performance is discussed.
Zirconium oxide thin film serves as one of the potential material candidates in extreme ultraviolet/soft x-ray optics applications. The suitability of its application can be justified by investigating its optical performance in the working energy range. In this study, we have investigated the soft x-ray optical properties of a zirconium oxide thin film near the O K-edge region using the energy-dependent soft x-ray reflectivity (SXR) technique. The SXR and absorption measurements are performed using the Indus-2 soft x-ray reflectivity beamline BL-03. The optical constants (δ and β) in the energy range of 500–560 eV covering O K-edge are extracted by applying Kramers–Kronig relations. Experimentally obtained δ and β profiles show a prominent eg and t2g feature in the vicinity of O K-edge with the crystal field splitting of 2.9 eV. All features observed in the δ and β spectra are correlated with their electronic structure and composition of the zirconium oxide thin film. Details of correlation between structural and optical properties as determined by x-ray absorption spectroscopy, x-ray photoelectron spectroscopy, and SXR analyses are discussed.
Transition elements exhibit strong correlations and configuration interactions between core and valence excited states, which give rise to different excitations inside materials. Nickel exhibits satellite features in its emission and absorption spectra. Effects of such transitions on the optical constants of nickel have not been reported earlier and the available database of Henke et al. does not represent such fine features. In this study, the optical behaviour of ion beam sputter deposited Ni thin film near the L
2,3-edge region is investigated using reflection spectroscopy techniques, and distinct signatures of various transitions are observed. The soft X-ray reflectivity measurements in the 500–1500 eV photon energy region are performed using the soft X-ray reflectivity beamline at the Indus-2 synchrotron radiation source. Kramers–Kronig analysis of the measured reflectivity data exhibit features corresponding to spin orbital splitting and satellite transitions in the real and imaginary part of the refractive index (refraction and absorption spectra). Details of fine features observed in the optical spectra are discussed. To the best of our knowledge, this is the first study reporting fine features in the measured optical spectra of Ni near its L
2,3-edge region.
Ni/AlN/Ni waveguide system provides intensity enhancement by a factor of ~30 at 8.05 keV photon energy. In the present study, the effect of deviation of structural parameters (thickness of each layer) along with the surface-interface properties on electric field intensity (EFI) inside an ion beam sputter deposited Ni/AlN/Ni waveguide is investigated. EFI calculations are performed using structural parameters obtained from X-ray reflectivity (XRR) measurements performed using Cu-Kα source. Deposited waveguide structure provides intensity enhancement (~26) slightly lower than optimized value (~30). Furthermore, temporal stability of the structure is investigated using combined XRR and grazing incidence X-ray fluorescence (GIXRF) techniques (at 15 keV photon energy) after about 15 months. Some structural changes are observed which, however, do not lead to further decrease in intensity enhancement inside the waveguide, making it suitable for applications at 8.05 keV photon energy.
Small bowel diverticulosis represents an uncommon pathology that is often misdiagnosed, since it causes non-specific gastrointestinal symptoms. It is defined by the existence of multiple diverticula, which are located most frequently in the jejunum. Acquired and congenital diverticula of the jejunum in the adult are unusual entity. These lesions are usually asymptomatic and may produce chronic symptoms. It is because of the rarity of the entity that they often produce a diagnostic as well as therapeutic dilemma resulting in unnecessary morbidity and mortality. This is a report on a case presented to emergency with features suggestive of perforation peritonitis with incidental finding of multiple small gut diverticula.
In the present study, structural and compositional analyses of reactive ion beam sputter deposited aluminum nitride (AlN) thin film of thickness 100 Å are carried out using x-ray reflectivity and x-ray photoelectron spectroscopy techniques. Soft x-ray optical response of the film is derived from energy dependent soft x-ray reflectivity measurements performed in photon energy region of 380–1700 eV. Optical constants (δ and β) obtained from the reflectivity spectra show features corresponding to absorption edges of the constituent elements. Observed fine features in the β profile are further confirmed from x-ray absorption (XAS) measurements carried out in the total electron yield mode. The measured XAS spectra are correlated with electronic and compositional properties of the AlN film. The effects of surface oxidation on soft x-ray optical properties of the AlN thin film are discussed.
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