6 research outputs found
Development of pixel super-resolution scanning transmission X-ray microscopy for material science
Die Entwicklung hochwertiger fokussierender Röntgenoptiken in den letzten Jahrzehnten hat die Transmissionsmikroskopie mit Röntgenstrahlung aus Synchrotronquellen ermöglicht. Proben lassen sich mit extrem hoher Ortsauflösung untersuchen, allerdings einerseits auf Kosten der BildfeldgröĂe (bis zu 100 ”m x 100 ”m) und andererseits bei eingeschrĂ€nktem Photonenenergiebereich (unter 20 keV), was den Einsatzbereich insbesondere in den Materialwissenschaften erheblich einschrĂ€nkt.
In dieser Arbeit fĂŒr den Bereich harter Röntgenstrahlung (17-35 keV) die so genannte rasternde superpixelauflösende Röntgentransmissionsmikroskopie entwickelt. Sie ermöglicht es, das Bildfeld zu vergröĂern und zugleich die Scanzeit drastisch zu reduzieren, indem die Probe mit einem durch refraktive bikonkav-parabolische Multilinsen erzeugten Feld aus Fokuspunkten abge-rastert wird. Die hochauflösenden Bilder haben eine rĂ€umliche Auflösung, in der GröĂenordnung der Röntgenfokusdurchmesser, und zwar auch wenn die PixelgröĂe des zur Datenerfassung eingesetzten Bilddetektors viel gröĂer ist als die FokusgröĂe.
Da das SchlĂŒsselelement der Technik eine Röntgenoptik ist, werden die Entwicklung und Herstellung einer (zwei)-dimensionalen brechenden Multilinse zur Fokussierung hochenergetischer Röntgenstrahlung vorgestellt, die mit Hilfe von Röntgentiefenlithographie und Galvanik hergestellt wurde. Es werden die Röntgencharakterisierung dieser Optiken und Mikroskopieexperimente vorgestellt, die an den Synchrotronquellen KARA (Deutschland), Diamond Light Source (England) und SPring-8 (Japan) durchgefĂŒhrt wurden. Da die Höhe der herkömmlichen refraktiven Multilinsen das Sichtfeld immer noch einschrĂ€nkt (bestenfalls im Millimeterbereich), wurde eine Treppenanordnung aus zum Substrat geneigten RMLs entwickelt, die eine pixel-superauflösende Rasterröntgenmikroskopie mit einem Bildfeld von 1.64 cm Ă 1.64 cm bei einer Auflösung von 780 ± 40 nm unter Verwendung von 35 keV Röntgenstrahlung ermöglicht. Die Scanzeit betrug nur etwa vier Minuten. Die einzigartigen Möglichkeiten der rasternden superpixelauf-lösenden Röntgentransmissionsmikroskopie mit harter Röntgenstrahlung wurde durch die Abbildung eines durch selektives Laserschmelzen aus Ti-6Al-4V hergestellten biomedizinischen Implantat-Abutments demonstriert. So wurde die Untersuchung ausgedehnter und dicker Proben fĂŒr die Materialwissenschaften demonstriert
Development of an Array of Compound Refractive Lenses for Sub-Pixel Resolution, Large Field of View, and Time-Saving in Scanning Hard X-ray Microscopy
A two-dimensional array of compound refractive lenses (2D array of CRLs) designed for hard X-ray imaging with a 3.5 mm large field of view is presented. The array of CRLs consists of 2D polymer biconcave parabolic 34 Ă 34 multi-lenses fabricated via deep X-ray lithography. The developed refractive multi-lens array was applied for sub-pixel resolution scanning transmission Xâray microscopy; a raster scan with only 55 Ă 55 steps provides a 3.5 megapixel image. The optical element was experimentally characterized at the Diamond Light Source at 34 keV. An array of point foci with a 55 ”m period and an average size of ca. 2.1 ”m Ă 3.6 ”m was achieved. In comparison with the conventional scanning transmission microscopy using one CRL, sub-pixel resolution scanning transmission hard X-ray microscopy enables a large field of view and short scanning time while keeping the high spatial resolution
Photon shot-noise limited transient absorption soft X-ray spectroscopy at the European XFEL
Femtosecond transient soft X-ray Absorption Spectroscopy (XAS) is a very
promising technique that can be employed at X-ray Free Electron Lasers (FELs)
to investigate out-of-equilibrium dynamics for material and energy research.
Here we present a dedicated setup for soft X-rays available at the Spectroscopy
& Coherent Scattering (SCS) instrument at the European X-ray Free Electron
Laser (EuXFEL). It consists of a beam-splitting off-axis zone plate (BOZ) used
in transmission to create three copies of the incoming beam, which are used to
measure the transmitted intensity through the excited and unexcited sample, as
well as to monitor the incoming intensity. Since these three intensity signals
are detected shot-by-shot and simultaneously, this setup allows normalized
shot-by-shot analysis of the transmission. For photon detection, the DSSC
imaging detector, which is capable of recording up to 800 images at 4.5 MHz
frame rate during the FEL burst, is employed and allows approaching the photon
shot-noise limit. We review the setup and its capabilities, as well as the
online and offline analysis tools provided to users.Comment: 11 figure
Determination of the weld thickness of turbine for aircraft engine by high-energy X-ray tomography
It is necessary to test the weld thickness of turbine, as it is one of the most important parts for aircraft engine. The weld thickness of turbine for aircraft engine by high-energy X-ray tomography was determined. We used an X-ray tube and a betatron as X-ray sources. The wall thickness of two tubes and weld thickness of turbine were measured. It is shown that the high-energy X-ray tomography system is determined the wall thickness of the tube and the weld thickness of turbine with high accuracy. We also studied the method to reduce scattered radiation. All experiments were carried out in the non-destructive testing (NDT) Institute of Tomsk Polytechnic University (TPU)
First results in the development of a mobile robot with trajectory planning and object recognition capabilities
The use of mobile robots is becoming popular in
many areas of service because they ensure safety and good
performance while working in dangerous or unreachable
locations. Areas of application of mobile robots differ from
educational research to detection of bombs and their disposal.
Based on the mission of the robot they have different
configurations and abilities â some of them have additional
arms, cranes and other tools, others use sensors
and built-in image processing and object recognition systems
to perform their missions. The robot that is described
in this paper is mobile robot with a turret mounted on top
of it. Different approaches have been tested while searching
for best method suitable for image processing and template
matching goals. Based on the information from image
processing unit the system executes appropriate actions
for planning motions and trajectory of the mobile
robot
Staircase array of inclined refractive multi-lenses for large field of view pixel super-resolution scanning transmission hard X-ray microscopy
Owing to the development of Xâray focusing optics during the past decades, synchrotronâbased Xâray microscopy techniques allow the study of specimens with unprecedented spatial resolution, down to 10â
nm, using soft and medium Xâray photon energies, though at the expense of the field of view (FOV). One of the approaches to increase the FOV to square millimetres is rasterâscanning of the specimen using a single nanoprobe; however, this results in a long data acquisition time. This work employs an array of inclined biconcave parabolic refractive multiâlenses (RMLs), fabricated by deep Xâray lithography and electroplating to generate a large number of long Xâray foci. Since the FOV is limited by the pattern height if a single RML is used by impinging Xârays parallel to the substrate, many RMLs at regular intervals in the orthogonal direction were fabricated by tilted exposure. By inclining the substrate correspondingly to the tilted exposure, 378000 Xâray line foci were generated with a length in the centimetre range and constant intervals in the subâmicrometre range. The capability of this new Xâray focusing device was first confirmed using rayâtracing simulations and then using synchrotron radiation at BL20B2 of SPringâ8, Japan. Taking account of the fact that the refractive lens is effective for focusing highâenergy Xârays, the experiment was performed with 35â
keV Xârays. Next, by scanning a specimen through the line foci, this device was used to perform large FOV pixel superâresolution scanning transmission hard Xâray microscopy (PSRâSTHXM) with a 780 ± 40â
nm spatial resolution within an FOV of 1.64â
cm Ă 1.64â
cm (limited by the detector area) and a total scanning time of 4â
min. Biomedical implant abutments fabricated via selective laser melting using Tiâ6Alâ4V medical alloy were measured by PSRâSTHXM, suggesting its unique potential for studying extended and thick specimens. Although the superâresolution function was realized in one dimension in this study, it can be expanded to two dimensions by aligning a pair of presented devices orthogonally.A new Xâray focusing device generates hundreds of thousands of line foci, periodically spaced in the subâmicrometre range, with centimetre length. It enables to achieve large FOV pixel superâresolution scanning transmission hard Xâray microscopy.
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