We present a laser-driven, bright, and broadband (50 to 1500 eV) soft-x-ray plasma source with <10 ps pulse duration. This source is employed in two complementary, laboratory-scale beamlines for time-resolved, magnetic resonant scattering and spectroscopy, as well as near-edge x-ray absorption fine-structure (NEXAFS) spectroscopy. In both beamlines, dedicated reflection zone plates (RZPs) are used as single optical elements to capture, disperse, and focus the soft x rays, reaching resolving powers up to E/ΔE > 1000, with hybrid RZPs at the NEXAFS beamline retaining a consistent E/ΔE > 500 throughout the full spectral range, allowing for time-efficient data acquisition.
View Article and Find Full Text PDFWe present a novel soft x-ray spectrometer for ultrafast absorption spectroscopy utilizing table-top femtosecond high-order harmonic sources. Where most commercially available spectrometers rely on spherical variable line space gratings with a typical efficiency on the order of 3% in the first diffractive order, this spectrometer, based on a Hettrick-Underwood design, includes a reflective zone plate as a dispersive element. An improved efficiency of 12% at the N K-edge is achieved, accompanied by a resolving power of 890.
View Article and Find Full Text PDFJ Laryngol Otol
August 2019
Objective: This study aimed to evaluate the results of routine endonasal endoscopic dacryocystorhinostomy combined with computed tomography guided navigation in patients with nasolacrimal duct obstruction.
Method: This was a retrospective study of all patients with lacrimal drainage obstruction undergoing stereotactic endoscopic dacryocystorhinostomy between 1st January 2016 and 1st April 2018. Computed tomography dacryocystography was used for intra-operative navigation.
Background: In addition to basic ophthalmologic diagnostic workup, different radiologic procedures can be performed for assessment of nasolacrimal duct obstruction. However, no gold standard imaging technique has yet been established. Using the results of the present study, the advantages of helical CT-dacryocystography (CT-DCG) are demonstrated, particularly when performed before endonasal endoscopic dacryocystorhinostomy.
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