FG Analytische Röntgenphysik

8 Items

Recent Submissions
Computational imaging methods for visible light and X-ray microscopy

Lötgering, Lars (2020)

In this thesis two computational imaging techniques, namely ptychographic coherent diffraction imaging and propagation-based phase retrieval, are explored. Central to both techniques are algorithmic aspects which are formulated in the framework of nonlinear optimization. Applications such as optical phase retrieval, x-ray beam characterization and lensless imaging are discussed both in theory a...

Laboratory based GIXRF and GEXRF spectrometers for multilayer structure investigations

Szwedowski-Rammert, Veronika ; Baumann, Jonas ; Schlesiger, Christopher ; Waldschläger, Ulrich ; Gross, Armin ; Kanngießer, Birgit ; Mantouvalou, Ioanna (2019-02-11)

This work reports laboratory angle resolved measurements with the goal of establishing laboratory techniques to obtain a more complete idea of the intralayer composition of multilayer samples. While X-ray reflectometry is a widely available technique for the characterization of multilayer samples, angle resolved XRF measurements (grazing emission/incidence X-ray fluorescence) are usually perfor...

New approaches in angle resolved X-ray analysis of stratified materials in the laboratory

Szwedowski-Rammert, Veronika (2019)

Providing access to angular resolved X-ray fluorescence methods in laboratories can enhance the dissemination of these methods for the depth-resolved elemental analysis of samples with layers in the nanometer range. The measurements are so far mainly performed at synchrotron radiation facilities and thus the number of users is limited. Especially in the hard X-ray range, where the production of...

Röntgenabsorptionsspektroskopie im Labor

Schlesiger, Christopher Philip (2019)

In der vorliegenden Arbeit wird ein flexibler Laboraufbau für Röntgenabsorptionsspektroskopie vorgestellt, mit dem es möglich, ist verdünnte Proben mit hoher Effizienz zu messen und zu charakterisieren. Das Ziel ist, durch diesen Aufbau den möglichen Anwenderkreis aufgrund der höheren Verfügbarkeit einer Labormethode, im Gegensatz zur üblichen Verwendung ausschließlich an Synchrotronstrahlungsq...

Advanced X-ray analytical methods for the characterization of buried interfaces with relevance for energy conversion devices

Baumann, Jonas (2017)

The efficiency of devices for novel renewable energy sources, like solar cells and thermoelectric generators (TEGs), is strongly increasing since the advent of nanotechnology. Synchrotron radiation-based advanced X-ray fluorescence (XRF) techniques, like grazing emission (GE-) or grazing incidence (GI-) XRF, offer non-destructive and quantitative access to elemental depth profiles in the nanome...

Energiedispersive Mikro-Röntgenfluoreszenzanalyse technischer Mikrostrukturen

Bremekamp, Marcel (2017)

Im Rahmen dieser Arbeit wurde ein FP-basiertes Voxelmodell entwickelt, das die Geometrieeffekte in der μ-EDRFA von Mikrostrukturen berücksichtigt und die Quantifizierung der Fluoreszenzintensitäten ermöglicht, die von diesen Mikrostrukturen emittiert werden. Zu diesem Zwecke wurde eine experimentelle Charakterisierung des Spektrometers bezüglich der spektralen Verteilung der Anregungsstrahlung ...

XAFS spectroscopy by an X-ray tube based spectrometer using a novel type of HOPG mosaic crystal and optimized image processing

Schlesiger, Christopher ; Anklamm, Lars ; Stiel, Holger ; Malzer, Wolfgang ; Kanngießer, Birgit (2015)

This paper presents recent achievements in laboratory based instrumentation for X-ray Absorption Fine Structure Spectroscopy (XAFS). The key component of the spectrometer is a HAPG mosaic crystal, which is employed in the von Hamos geometry. Due to the high efficiency of HAPG a low power micro focus X-ray tube can serve as an X-ray source. Besides a description of the spectrometer, the paper co...

Combined 1D, 2D and 3D micro-XRF techniques for the analysis of illuminated manuscripts

Lachmann, Tim ; Snickt, Geert van der ; Haschke, Michael ; Mantouvalou, Ioanna (2016)

The combination of several micro-XRF analysis modes is presented for the investigation of an illuminated parchment manuscript. With a commercial instrument, conventional micro-XRF spot analysis (0D) and mapping (2D) are performed, yielding detailed lateral elemental information. Depth resolution becomes accessible by mounting an additional polycapillary lens in front of an SDD detector. Quantit...