Comparison of different sources for laboratory X-ray microscopy

This paper describes the setup of two different solutions for laboratory X-ray microscopy working with geometric magnification. One setup uses thin-film transmission targets with an optimized tungsten-layer thickness and the electron gun and optics of an electron probe micro analyzer to generate a very small X-ray source. The other setup is based on a scanning electron microscope and uses microstructured reflection targets. We also describe the structuring process for these targets. In both cases we show that resolutions of 100 nm can be achieved. Also the possibilities of computed tomography for 3D imaging are explored and we show first imaging examples of high-absorption as well as low-absorption specimens to demonstrate the capabilities of the setups.Comment: 6 pages, 4 figures, proceedings of the 14th International Workshop on Radiation Imaging Detector

Comparing Image Quality in Phase Contrast subμ\mu X-Ray Tomography -- A Round-Robin Study

How to evaluate and compare image quality from different sub-micrometer (sub$\mu$) CT scans? A simple test phantom made of polymer microbeads is used for recording projection images as well as 13 CT scans in a number of commercial and non-commercial scanners. From the resulting CT images, signal and noise power spectra are modeled for estimating volume signal-to-noise ratios (3D SNR spectra). Using the same CT images, a time- and shape-independent transfer function (MTF) is computed for each scan, including phase contrast effects and image blur ($\mathrm{MTF_{blur}}$). The SNR spectra and MTF of the CT scans are compared to 2D SNR spectra of the projection images. In contrary to 2D SNR, volume SNR can be normalized with respect to the object's power spectrum, yielding detection effectiveness (DE) a new measure which reveals how technical differences as well as operator-choices strongly influence scan quality for a given measurement time. Using DE, both source-based and detector-based sub$\mu$ CT scanners can be studied and their scan quality can be compared. Future application of this work requires a particular scan acquisition scheme which will allow for measuring 3D signal-to-noise ratios, making the model fit for 3D noise power spectra obsolete

Röntgen

Mit der industriellen Röntgentechnik steht ein Werkzeug für die zerstörungsfreie Prüfung zur Verfügung, mit dem sich im Materialinneren verborgene Strukturen beliebig komplexer Objekte aus zahlreichen Werkstoffen mit hoher qualitativer wie quantitativer Genauigkeit erfassen und charakterisieren lassen. Die Palette der etablierten Techniken reicht dabei von der digitalen Radioskopie über die Computertomographie bis hin zur Rück- und Kleinwinkeltreuung

Bildgebende Sensoren, Bildauswerteverfahren

Bildgebende Sensoren sind vielfältig einsetzbar. Da sie aus einer Matrix von Einzelsensoren bestehen, erhält man eine sehr große Datenmenge, in der extrem viele Informationen stecken. Die nötigen Informationen aus der großen Datenmenge zu extrahieren ist die hohe Kunst der Bildverarbeitung oder Bildanalyse. Dieser Beitrag soll einen kurzen Einblick in die Möglichkeiten aber auch Grenzen der industriellen Bildverarbeitung (IBV) verschaffen. Insbesondere unter den Aspekten der Techniken für erneuerbare Energien

A CT system for the analysis of prehistoric ice cores

The task was to measure ice cores with a diameter of 10 cm and a length of 1 m that were drilled out of Arctic and Antarctic glaciers down to 3,000 m depth. By means of computed tomography (CT), pieces of 1 m length are measured and three-dimensional volume data with high spatial resolution are reconstructed. Complex image processing algorithms are applied to analyze the volume regarding its mean porosity as a function of depth, its total mean porosity and the volumetric distribution of the pores. Since high image quality is required to achieve precise results, a vast amount of data is acquired. The geometry of the samples increases the requirements for the X-ray components. Furthermore measurements have to be made in an environment of -15 C

Laboratory-Based Nano-Computed Tomography and Examples of Its Application in the Field of Materials Research

In a comprehensive study, we demonstrate the performance and typical application scenarios for laboratory-based nano-computed tomography in materials research on various samples. Specifically, we focus on a projection magnification system with a nano focus source. The imaging resolution is quantified with common 2D test structures and validated in 3D applications by means of the Fourier Shell Correlation. As representative application examples from nowadays material research, we show metallization processes in multilayer integrated circuits, aging in lithium battery electrodes, and volumetric of metallic sub-micrometer fillers of composites. Thus, the laboratory system provides the unique possibility to image non-destructively structures in the range of 170–190 nanometers, even for high-density materials