TY - JOUR
A1 - Sittner, Jonathan
A1 - Götze, Jens
A1 - Müller, Axel
A1 - Renno, Axel D.
A1 - Ziegenrücker, René
A1 - Pan, Yuanming
T1 - Trace element analysis and luminescence behavior of quartz in pegmatites of the Tørdal Region, Norway
N2 - This publication presents a study on the mineral chemistry and luminescence properties of quartz samples from pegmatites of the Tørdal region in Norway. A total of 12 samples were analyzed using Secondary Ion Mass Spectrometry (SIMS), Electron Paramagnetic Resonance Spectroscopy (EPR), and Cathodoluminescence (CL) to gain insights into their trace element concentration and distribution as well as their luminescence behavior. The samples are characterized by different Cl emissions at 450 nm, 500 nm 650 nm and an additional shoulder at 390 nm, which is only partially visible due to the absorption of the glass optics. Of these luminescence bands, the 500 nm band is the most dominant in most samples and it is characterized by an initial blue-green luminescence, which is not stable under electron irradiation. Moreover, it is characterized by a heterogeneous distribution within the samples. This luminescence can be mostly assigned to [AlO4/M+]0 defects, with charge compensation mostly achieved by Li+. Analyses by EPR spectroscopy prove the dominance of structurally bound Al, Li, and Ti ions in the investigated samples. Further analyses using SIMS mapping demonstrate that Na and K are mainly bound to micro fractures or inclusions, suggesting a limited role in the compensation of the luminescence centers. Additionally, the SIMS mappings show that some samples contain Al-rich clusters of 10 to 20 µm in diameter, whereas other trace elements are characterized by a homogeneous distribution. These clusters correspond to bright luminescence areas in size and shape and could potentially indicate H+ compensated [AlO4/M+]0 defects.
KW - Quartz
KW - Trace elements
KW - SIMS
KW - Cathodoluminescence
KW - EPR
KW - Tørdal
KW - Pegmatite
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-612529
DO - https://doi.org/10.1016/j.chemgeo.2024.122427
VL - 670
SP - 1
EP - 15
PB - Elsevier BV
AN - OPUS4-61252
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Laquai, René
A1 - Schaupp, Thomas
A1 - Müller, Bernd R.
A1 - Griesche, Axel
A1 - Kupsch, Andreas
A1 - Lange, Axel
A1 - Kannengießer, Thomas
A1 - Bruno, Giovanni
T1 - 3D Crack analysis in hydrogen charged lean duplex stainless steel with synchrotron refraction CT
N2 - Hydrogen in metals can cause a degradation of the mechanical properties, the so-called hydrogen embrittlement. In combination with internal stresses, hydrogen assisted cracking (HAC) can occur. This phenomenon is not completely understood yet. To better characterise the cracking behaviour, it is important to gain information about the evolution of the 3D crack network. For this purpose samples of lean duplex stainless steel were loaded with hydrogen by means of electrochemical charging and investigated by means of synchrotron refraction CT and SEM fractography after uniaxial tensile loading. Synchrotron refraction CT is an analyser-based imaging (ABI) technique. It uses a Si (111) single crystal as analyser, which is placed into the beam path between sample and detector. According to Bragg’s law only incident x-rays within a narrow range around the Bragg-angle are diffracted from the analyser into the detector. Hence, the analyser acts as an angular filter for the transmitted beam. This filtering allows to turn the refraction and scattering of x-rays into image contrast. Refraction occurs at all interfaces, where the density of the material changes and is more sensitive to density changes than the attenuation. Therefore, it is possible to detect smaller cracks than with classical x-ray imaging techniques, like CT, with comparable spacial resolution. It also visualises the 3D structure of the cracks and gains quantitative information about their morphology and distribution. Since cracks introduced by HAC are usually very small and have a small opening displacement, synchrotron refraction CT is expected to be well suited for imaging this cracking mechanism and can be a valuable tool to characterise the formation and the evolution of a 3D crack network.
T2 - WCNDT 2016
CY - München, Germany
DA - 13.06.2016
KW - X-ray refraction
KW - Computed tomography
KW - Hydrogen assisted cracking
KW - Duplex stainless steel
PY - 2016
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-366481
SN - 978-3-940283-78-8
VL - BB 158
SP - Tu.4.B.3, 1
EP - 9
AN - OPUS4-36648
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Ewers, Benjamin
A1 - Kupsch, Andreas
A1 - Lange, Axel
A1 - Müller, Bernd R.
A1 - Hoehl, a.
A1 - Müller, R.
A1 - Ulm, G.
T1 - Terahertz spectral computed tomography
N2 - The novel technique of spectral THz computed tomography is demonstrated at an example of a small plastic figure. The data are reconstructed by conventional filtered back-projection. The reconstruction are discussed.
T2 - IRMMW-THz 2009 - 34th International conference on infrared, millimeter, and terahertz waves
CY - Busan, Korea
DA - 2009-09-21
KW - THz
KW - Computed tomography
PY - 2009
SN - 978-1-4244-2120-6
SP - 1
EP - 2(?)
AN - OPUS4-20546
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Müller, Axel
A1 - Goedecke, Caroline
A1 - Eisentraut, Paul
A1 - Piechotta, Christian
A1 - Braun, Ulrike
T1 - Microplastic analysis using chemical extraction followed by LC‑UV analysis: a straightforward approach to determine PET content in environmental samples
N2 - Background: The ubiquitous occurrence of microplastic particles in marine and aquatic ecosystems was intensively investigated in the past decade. However, we know less about the presence, fate, and input paths of microplastic in terrestrial ecosystems. A possible entry path for microplastic into terrestrial ecosystems is the agricultural application of sewage sludge and solid bio-waste as fertilizers. Microplastic contained in sewage sludge also includes Polyethylene terephthalate (PET), which could originate as fiber from textile products or as a fragment from packaging products (foils, bottles, etc.). Information about microplastic content in such environmental samples is limited yet, as most of the used analytical methods are very time-consuming, regarding sample preparation and detection, require sophisticated analytical tools and eventually need high user knowledge.
Results: Here, we present a simple, specific tool for the analysis of PET microplastic particles based on alkaline extraction of PET from the environmental matrix and subsequent determination of the monomers, terephthalic acid, using liquid chromatography with UV detection (LC-UV). The applicability of the method is shown for different types of PET in several soil-related, terrestrial environmental samples, e.g., soil, sediment, compost, fermentation residues, but also sewage sludge, suspended particles from urban water management systems, and indoor dust. Recoveries for model samples are between 94.5 and 107.1%. Limit of determination and limit of quantification are absolute masses of 0.031 and 0.121 mg PET, respectively. In order to verify the measured mass contents of the environmental samples, a method comparison with thermal extraction-desorption-gas chromatography–mass spectrometry (TED-GC/MS) was conducted. Both methods deliver similar results and corroborated each other. PET mass contents in environmental samples range from values below LOQ in agriculture soil up to 57,000 mg kg−1 in dust samples.
Conclusions: We demonstrate the potential of an integral method based on chemical extraction for the Determination of PET mass contents in solid environmental samples. The method was successfully applied to various matrices and may serve as an analytical tool for further investigations of PET-based microplastic in terrestrial ecosystems.
KW - Soil
KW - Analysis
KW - Microplastic
KW - PET
KW - LC-UV
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509060
DO - https://doi.org/10.1186/s12302-020-00358-x
IS - 32
SP - 85
PB - Springer Open
CY - Berlin
AN - OPUS4-50906
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Müller, Axel
T1 - Analysis of tire wear particles in soil samples from roadside using TED-GC/MS
N2 - Tire wear particles (TW) are generated by the abrasions of tires on the road surface through traffic. These particles can be transported by air and surface runoff and might also infiltrate the soil and consequently affect terrestrial ecosystems. The estimated tire wear (TW) emissions are immense, with 1.33 106 t a-1 in Europe. Despite this, only little is known about the environmental contents or the fate of TW.
One reason for this knowledge gap is the challenging analysis of TW in environmental samples. Detection of TW with spectroscopic methods is problematic due to high fluorescence interferences caused by contained black carbon. One analytical approach is to use zinc (Zn), a typical additive in tires, as a specific marker for the quantification of tire wear. However, any Zn originating from the sample matrix must be separated beforehand and requires elaborate sample preparation.
Car tires consist partly of synthetic rubbers, such as styrene-butadiene-rubber (SBR). This SBR could be identified and quantified via Thermal-Extraction-Desorption-Gas Chromatography-Mass Spectrometry (TED-GC-MS). This newly developed and fast screening method allows the simultaneous detection of microplastics and TW mass contents and requires minimal to no sample preparation. Firstly the sample is thermally extracted in a thermobalance under a nitrogen atmosphere. The resulting specific decomposition products are sorbed on a solid phase adsorber, which is then transferred to a GC-MS via an autosampler, where the products are desorbed, separated and identified. Cyclohexenylbenzene is used as a specific marker for SBR.
Here we investigated top layer soil samples, collected at the roadside of highly frequented German highways. Samples were analyzed without sample preparation, and SBR was detected in all investigated samples in mass contents ranging from 67.2 to 2230 mg kg-1. A correlation between SBR and Zn content in the soil was confirmed, while the correlation between SBR and Corg was hardly pronounced. We successfully demonstrated the application of TED-GC-MS as a screening method for tire wear in soil samples.
The present study will discuss these analytical results in detail as well as sampling parameters like sampling depth and distance to the roadside, and the effect of the particle size on the particle transport by water runoff and air.
T2 - SETAC 2020 SciCon
CY - Online meeting
DA - 03.05.2020
KW - Microplastic
KW - Analysis
KW - Tire wear
KW - Soil
PY - 2020
AN - OPUS4-51086
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Müller, Axel
T1 - Einfluss der Alterung auf das Sorptionsverhalten von Mikroplastik, eine Laborstudie mit BTEX und Etherverbindungen
N2 - Mikroplastik (MP) findet sich in aquatischen Ökosystemen weltweit und es konnte gezeigt werden, dass hydrophobe organische Schadstoffe an MP angereichert werden. Es ist bekannt, dass teilkristalline und amorphe Polymere unterschiedliche Sorptionsver-halten aufweisen. Der Einfluss des Alterungszustandes der MP-Partikel auf das Sorptionsverhalten ist nicht hinreichend geklärt. In dieser Studie wurden amorphes Polystyrol (PS) und teilkristallines Polypropylen (PP) in Form von Industriepellets gezielt gealtert und mikroskopisch sowie mittels XPS, FTIR und DSC charakterisiert. Anschließend wurde in Batchexperimenten die Sorption von potenziell wassergefährdenden Kraftstoffbestandteilen (Ether und BTEX) an den Pellets mittels Headspace-Gaschromatografie untersucht.
T2 - Wasser 2017 - Jahrestagung der Wasserchemischen Gesellschaft
CY - Donaueschingen, Germany
DA - 22.05.2017
KW - Mikroplastik
KW - Alterung
KW - Sorption
KW - BTEX
PY - 2017
AN - OPUS4-40445
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Müller, Axel
A1 - Becker, Roland
A1 - Braun, Ulrike
A1 - Dorgerloh, Ute
T1 - Einfluss der Alterung auf das Sorptionsverhalten von Mikroplastik, eine Laborstudie mit BTEX und Etherverbindungen
N2 - Die Präsenz von Mikroplastik in aquatischen Ökosystemen ist ein globales Problem und steht zunehmend im Fokus der Öffentlichkeit. In mehreren Studien konnten Anreicherungen hydrophober, organischer Schadstoffe an MP nachgewiesen werden. Der Einfluss des Alterungszustandes der MP-Partikel auf das Sorptionsverhalten von hydrophoben organischen Substanzen ist nicht hinreichend geklärt.
Ziel der vorliegenden Arbeit war die Untersuchung des Sorptionsverhaltens von Schadstoffen mit Bedeutung für limnische Gewässer an künstlich gealterten Partikeln relevanter Polymere. Das Modell verwendete die Aromaten Benzol, Toluol, Ethylbenzol und Xylol (BTEX) sowie Etherverbindungen. Diese Substanzen sind oder waren Bestandteile in unterschiedlichen Kraftstoffen und finden sich daher in vielen aquatischen Ökosystemen weltweit. Als Sorbentien kamen teilkristallines Polypropylen (PP) und amorphes Polystyrol (PS) in Form von Industriepellets zum Einsatz. Die Pellets wurden jeweils sowohl unbehandelt als auch mittels UV-Bestrahlung künstlich gealtert verwendet und mikroskopisch sowie mittels XPS, FTIR und DSC charakterisiert. Die Alterung führte bei PS zu einer verringerten Sorptionskapazität, während bei PP keine Veränderung im Sorptionsverhalten beobachtet wurde.
T2 - Wasser 2017 - Jahrestagung der Wasserchemischen Gesellschaft
CY - Donaueschingen, Germany
DA - 22.05.2017
KW - Mikroplastik
KW - Organische Schadstoffe
KW - Sorption
KW - Polypropylen Polystyrol
PY - 2017
SN - 978-3-947197-01-9
SP - 1
EP - 606
PB - Gesellschaft Dt. Chemiker
AN - OPUS4-40447
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Hentschel, Manfred P.
A1 - Harbich, Karl-Wolfram
A1 - Lange, Axel
A1 - Schors, Jörg
A1 - Müller, Bernd R.
T1 - Röntgen-Topographie mit Klein- und Weitwinkel-Streuung
N2 - Röntgen-Topographische Verfahren sind dadurch gekennzeichnet, daß die Streueigenschaften eines Probekörpers ortskorreliert erfaßt werden. Somit vereinigen sie die Vorzüge der bildgebenden Eigenschaft der Radiographie mit der Strukturselektivität der Röntgenanalyse. Sowohl die Röntgen-Weitwinkel-Streuung als auch die Röntgen-Kleinwinkel-Streuung (-Beugung und -Refraktion) werden topographisch für die Materialcharakterisierung eingesetzt. Die Topographie-Verfahren und Untersuchungsbeispiele an nichtmetallischen Werkstoffen werden dargestellt.
T2 - Jahrestagung Zerstörungsfreie Materialprüfung 2002
CY - Weimar, Deutschland
DA - 2002-05-06
KW - Röntgen-Streuung
KW - Materialcharakterisierung
KW - Komposite
KW - Keramik
PY - 2002
UR - http://www.ndt.net/article/dgzfp02/papers/v15/v15.htm
SN - 3-931381-39-0
N1 - Serientitel: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V. – Series title: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V.
IS - 80-CD
PB - DGZfP
CY - Berlin
AN - OPUS4-2027
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hentschel, Manfred P.
A1 - Kupsch, Andreas
A1 - Lange, Axel
A1 - Müller, Bernd R.
A1 - Schors, Jörg
T1 - Das Anwendungspotential der Röntgen-Topographie vom Mikroriss bis zur Gepäckprüfung
T2 - DGZfP-Jahrestagung 2007
CY - Fürth, Deutschland
DA - 2007-05-14
KW - CFK
KW - Bildgebende Röntgenverfahren
KW - Röntgen-Topographie und -Streuung
KW - Keramik
KW - Explosivstoffe
KW - Ermüdungsrisse
PY - 2007
SN - 978-3-931381-98-1
SP - 1
EP - 9
PB - DGZfP
CY - Berlin
AN - OPUS4-15799
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Harwardt, Marco
A1 - Hentschel, Manfred P.
A1 - Illerhaus, Bernhard
A1 - Goebbels, Jürgen
A1 - Bamberg, J.
A1 - Heutling, F.
ED - Danny Van Hemelrijck,
ED - Igor Solodov,
ED - Anastasopoulos, Athanasios
ED - Gerhard Busse,
T1 - Synchrotron-Refraction-Computed-Tomography for NDT and characterisation of lightweight composite materials
T2 - 4th International Conference of Emerging Technologies in Non-Destructive Testing (ETNDT 4)
CY - Stuttgart, Germany
DA - 2007-04-02
KW - Refraction
KW - Computed Tomography
KW - NDE
KW - Ti-MMC
PY - 2008
SN - 978-0-415-46476-5
SP - 217
EP - 221
PB - Taylor & Francis
CY - London, UK
AN - OPUS4-18680
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Harwardt, Michael
A1 - Hentschel, Manfred P.
A1 - Illerhaus, Bernhard
A1 - Goebbels, Jürgen
A1 - Bamberg, J.
A1 - Heutling, F.
T1 - Micro Crack Characterization of Metal Matrix Composites by 3D-Refraction-Computed-Tomography
T2 - 16th World Conference on Nondestructive Testing
CY - Montreal, Canada
DA - 2004-08-30
KW - NDE
KW - X-ray refraction
KW - Composites
KW - MMC
PY - 2004
SP - 9 pages
PB - International Committee for Non-Destructive Testing
CY - Montreal
AN - OPUS4-5486
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hentschel, Manfred P.
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Harbich, Karl-Wolfram
A1 - Schors, Jörg
A1 - Wald, Oliver
T1 - New Developments in X-ray-Topography of Advanced Non-Metallic Materials
T2 - 15th World Conference on Non-Destructive Testing (WCNDT)
CY - Roma, Italy
DA - 2000-10-15
PY - 2000
UR - http://www.ndt.net/article/wcndt00/papers/idn258/idn258.htm
SN - 1435-4934
VL - 5
IS - 11
PB - NDT.net
CY - Kirchwald
AN - OPUS4-928
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Harwardt, Michael
A1 - Hentschel, Manfred P.
T1 - Submikro-Computer-Tomographie an der BAMline
T2 - Jahrestagung Zerstörungsfreie Materialprüfung 2004
CY - Salzburg, Österreich
DA - 2004-05-17
KW - Computer Tomographie
KW - Vergrößerung mit asymmetrischen Kristallen
PY - 2004
UR - http://www.ndt.net/article/dgzfp04/papers/v09/v09.htm
SN - 3-931381-55-2
SP - 1(?)
EP - 7(?)
PB - DGZfP
CY - Berlin
AN - OPUS4-5869
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Müller, Bernd R.
A1 - Hentschel, Manfred P.
A1 - Lange, Axel
A1 - Harwardt, Michael
T1 - Characterization of fibre reinforced metals by X-ray refraction CT
PY - 2003
UR - http://www.helmholtz-berlin.de/media/media/oea/web/pr_webseite/druckschriften/berichte/bessy/annualreport2002.pdf#page=336
SN - 0179-4159
SP - 336
EP - 337
PB - Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung
CY - Berlin
AN - OPUS4-2493
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Harwardt, Michael
A1 - Hentschel, Manfred P.
A1 - Illerhaus, Bernhard
A1 - Goebbels, Jürgen
A1 - Bamberg, J.
A1 - Heutling, F.
T1 - X-Ray Refraction Topography and Computed Tomography for NDE of Lightweight Materials
T2 - 9th European Conference on NDT
CY - Berlin, Germany
DA - 2006-09-25
KW - Synchrotron Refraction CT
KW - MMC
KW - Bragg-Magnification
PY - 2006
SN - 3-931381-86-2
SP - 1(?)
EP - 9(?)
PB - European Federation for Non-Destructive Testing
CY - Berlin
AN - OPUS4-13703
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Müller, Bernd R.
A1 - Hentschel, Manfred P.
A1 - Harbich, Karl-Wolfram
A1 - Lange, Axel
A1 - Schors, Jörg
T1 - X-Ray Refraction Topography for Non-Destructive Evaluation of Advanced Materials
KW - X-Ray Refraction
KW - Fibre Debonding
KW - Topography
KW - Crack Density
KW - Pore Size
KW - SAXS
PY - 2001
SP - 1
EP - 7
PB - Society of Manufacturing Engineers
CY - Dearborn, Mich.
AN - OPUS4-1097
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Harwardt, Michael
A1 - Hentschel, Manfred P.
A1 - Illerhaus, Bernhard
A1 - Goebbels, Jürgen
T1 - Synchrotron Refraction CT and Synchrotron Bragg Magnification CT for NDE
N2 - X-ray refraction topography techniques are based on ultra-small angle scattering by micro-structural elements causing phase-related effects such as refraction and total reflection at a few minutes of arc as the refractive index of X-rays is nearly unity. The refraction contrast is several times higher than true absorption and results in images of cracks, pores and fibre debonding separations below the spatial resolution of the detector. In most cases the investigated inner surface and interface structures correlate to mechanical properties. For the exploration of micro structured materials the refraction technique has been improved by a 3D Synchrotron Refraction Computed Tomography test station. The specimen is placed in an X-ray beam between two single crystals, which suppresses all sample scattering. In addition, an asymmetric cut second crystal can magnify the image up to 50 times revealing nano meter resolution. The technique is an alternative to other attempts on raising the spatial resolution of CT machines.
KW - X-ray refraction
KW - Diffraction Enhanced Imaging (DEI)
KW - Bragg magnification
KW - Synchrotron radiation
KW - Computed Tomography (CT)
KW - Metal Matrix Composites (MMC)
KW - Lightweight materials
KW - Aerospace
PY - 2008
DO - https://doi.org/10.1784/insi.2008.50.6.316
SN - 0007-1137
VL - 50
IS - 6
SP - 316
EP - 319
PB - British Institute of Non-Destructive Testing
CY - Northampton
AN - OPUS4-18001
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Tilgner, R.
A1 - Alpern, P.
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Harwardt, Marco
A1 - Hentschel, Manfred P.
T1 - Package induced deformation of integrated circuits
KW - Synchrotron Laue Contrast Radiography SLCR
KW - Synchrotron Radiation
KW - Electronic Power Device IC
PY - 2007
UR - http://www.helmholtz-berlin.de/media/media/oea/web/pr_webseite/druckschriften/infos/bessy/highlights2006.pdf#page=26
SN - 1611-6127
SP - 24
EP - 25
PB - Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung
CY - Berlin
AN - OPUS4-15797
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Harwardt, Michael
A1 - Hentschel, Manfred P.
A1 - Illerhaus, Bernhard
A1 - Goebbels, Jürgen
T1 - First refraction enhanced 3D computed tomography
T2 - International Symposium on Computed Tomography and Image Processing for Industrial Radiology
CY - Berlin, Germany
DA - 2003-06-23
PY - 2003
SN - 3-931381-48-X
N1 - Serientitel: DGZfP-Proceedings BB – Series title: DGZfP-Proceedings BB
IS - 84-CD
PB - DGZfP
CY - Berlin
AN - OPUS4-2519
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Kupsch, Andreas
A1 - Hentschel, Manfred P.
A1 - Lange, Axel
A1 - Müller, Bernd R.
T1 - X-ray dark field imaging
N2 - A new kind of enhanced contrast X-ray imaging of weakly absorbing materials in dark field mode is presented.
Samples such as plastics and biological tissue are a perpetual challenge for radiographic imaging. Recent innovative approaches such as Diffraction Enhanced Imaging (DEI), “phase contrast”, grating interferometry (Talbot-Lau), or Refraction Enhanced Imaging (REI) have in common that they yield enhanced contrast based on deflected X-rays.
Here, we introduce a REI modification, which works with a slightly bent single crystal reflecting in Bragg geometry. The samples are placed upstream of the thin crystal within a parallel synchrotron beam. The crystal’s curvature creates a dark-field stripe in the transmission image, similar to the inverse of a Darwin-Prins rocking curve of plane crystals. The reflection condition is met better or worse as a steady function of incidence position.
Refracted beam portions of sample interfaces appear bright on black stripes. The entire image is finally synthesized by multiple dark-field stripes. The technique is an alternative to the mentioned techniques. We demonstrate the technique’s advantage by examples of biological and technical microstructures.
T2 - ECNDT 2014 - 11th European conference on non-destructive testing
CY - Prague, Czech Republic
DA - 06.10.2014
KW - X-ray refraction
KW - Refraction enhanced imaging (REI)
KW - Phase contrast
KW - Radiology
KW - Soft matter radiography
PY - 2014
SN - 978-80-214-5018-9
SP - 1
EP - 7
AN - OPUS4-31971
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Harwardt, Michael
A1 - Hentschel, Manfred P.
T1 - Synchrotron-based micro-CT and refraction-enhanced micro-CT for non-destructive materials characterisation
N2 - X-ray computed tomography is an important tool for non-destructively evaluating the 3-D microstructure of modern materials. To resolve material structures in the micrometer range and below, high brilliance synchrotron radiation has to be used. The Federal Institute for Materials Research and Testing (BAM) has built up an imaging setup for micro-tomography and -radiography (BAMline) at the Berliner storage ring for synchrotron radiation (BESSY). In computed tomography, the contrast at interfaces within heterogeneous materials can be strongly amplified by effects related to X-ray refraction. Such effects are especially useful for materials of low absorption or mixed phases showing similar X-ray absorption properties that produce low contrast. The technique is based on ultra-small-angle scattering by microstructural elements causing phase-related effects, such as refraction and total reflection. The extraordinary contrast of inner surfaces is far beyond absorption effects. Crack orientation and fibre/matrix debonding in plastics, polymers, ceramics and metal-matrix-composites after cyclic loading and hydro-thermal aging can be visualized. In most cases, the investigated inner surface and interface structures correlate to mechanical properties. The technique is an alternative to other attempts on raising the spatial resolution of CT machines.
KW - Refraction
KW - Computed tomography
KW - NDE
KW - Ti-MMC
KW - Lightweight materials
KW - Metal matrix composites
KW - Synchrotron radiation
KW - X-ray refraction
PY - 2009
DO - https://doi.org/10.1002/adem.200800346
SN - 1438-1656
VL - 11
IS - 6
SP - 435
EP - 440
PB - Wiley-VCH Verl.
CY - Weinheim
AN - OPUS4-20564
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Harwardt, Michael
A1 - Hentschel, Manfred P.
T1 - Characterization of metal matrix composites by synchrotron refraction computed topography
KW - Metal matrix composites
KW - Refraction
KW - Synchrotron radiation
KW - Computed tomography
KW - Analyzer based imaging
KW - Diffraction enhanced imaging
PY - 2010
DO - https://doi.org/10.4028/www.scientific.net/MSF.638-642.967
SN - 0255-5476
VL - 638-642
SP - 967
EP - 972
PB - Trans Tech Publications
CY - Aedermannsdorf, Switzerland
AN - OPUS4-20563
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Lange, Axel
A1 - Müller, Bernd R.
A1 - Hentschel, Manfred P.
A1 - Kupsch, Andreas
T1 - Korrektur des Hinterleuchtens an CT-Synchrotrondaten
N2 - In den unterschiedlichsten Methoden der Computertomographie tritt häufig ein diffuses Untergrundsignal in den Einzelprojektionen auf: im Falle der Parallelstrahl-CT mit Synchrotronstrahlung handelt es sich um ein Hinterleuchten durch den Fluoreszenzschirm, der vor der CCD-Kamera angeordnet ist. Dieses Hinterleuchten unterscheidet sich von dem bekannten Nachleuchten (Phosphoreszenz) durch zeitliche Konstanz.
Hier äußert sich das Hinterleuchten als Modulation der projizierten Masse und somit als Funktion der Phase (Projektionswinkel) und des Aspektverhältnisses des Objektes. Der Einfluss des Hinterleuchtens ist abhängig von der Größe des von der Probe abgeschatteten Detektorbereiches und des Objektumfangs (Dynamik). Dies hat u.a. zur Folge, dass Abweichungen vom Absorptionsgesetz auftreten, die umso
stärker ausgeprägt sind, je weniger Detektorfläche das Objekt abdeckt und je stärker das Objekt schwächt. Dabei können Aufhärtungseffekte wegen der monochromatischen Strahlung ausgeschlossen werden.
Mit Referenzmessungen und einem isotropen, homogenen Ansatz, der diese Abweichung als Hinterleuchten beschreibt, lassen sich die auftretenden Fehler deutlich verringern.
T2 - DGZfP-Jahrestagung 2011
CY - Bremen, Germany
DA - 30.05.2011
KW - Hinterleuchten
KW - Detektor
KW - Fluoreszenzschirm
KW - Synchrotron-Radiographie
KW - Computer-Tomographie
PY - 2011
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-250038
SN - 978-3-940283-33-7
IS - DGZfP-BB 127 (P6)
SP - 1
EP - 8
PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP)
AN - OPUS4-25003
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Issever, A.S.
A1 - Diederichs, G.
A1 - Majumdar, S.
A1 - Rogalla, P.
A1 - Hamm, B.K.
A1 - Lange, Axel
A1 - Harwardt, Michael
A1 - Hentschel, Manfred P.
A1 - Müller, Bernd R.
T1 - Analyser-based tomography images of cartilage
N2 - Analyser-based imaging expands the performance of X-ray imaging by utilizing not only the absorption properties of X-rays but also the refraction and scatter rejection (extinction) properties. In this study, analyser-based computed tomography has been implemented on imaging an articular cartilage sample, depicting substructural variations, without overlay, at a pixel resolution of 3.6 µm.
KW - Cartilage
KW - Analyser-based imaging
KW - Computed tomography
PY - 2008
DO - https://doi.org/10.1107/S0909049508014829
SN - 0909-0495
SN - 1600-5775
VL - 15
IS - Part 5
SP - 525
EP - 527
PB - Blackwell Publishing
CY - Oxford
AN - OPUS4-17852
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Harwardt, Michael
A1 - Hentschel, Manfred P.
T1 - Synchrotron-Refraktions-Computer-Tomographie - EIne neue Methode zur Erkennung von Grenzflächen
T2 - DGZfP-Jahrestagung 2009
CY - Münster, Deutschland
DA - 2009-05-18
KW - Synchrotronstrahlung
KW - Refraktion
KW - Diffraktion
KW - Kleinwinkelstreuung
KW - Materialcharakterisierung
KW - Zerstörungsfrei
PY - 2009
SN - 978-3-940283-16-0
IS - DGZfP-BB 115 (Di.1.A.1)
SP - 1
EP - 11
AN - OPUS4-20609
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Harwardt, Michael
A1 - Hentschel, Manfred P.
A1 - Illerhaus, Bernhard
A1 - Goebbels, Jürgen
A1 - Bamberg, J.
A1 - Heutling, F.
T1 - Refraction computed tomography - Application to metal matrix composites
N2 - Erstmals wurden MMCs mit Hilfe der Interface-Kontrast verstärkenden Röntgen-Refraktions-Technik in Kombination mit der 3D-CT-Technik untersucht. Die Methode der Röntgen-Refraktions-Topography sowie der Röntgen-Refraktions-Tomography wurden in den letzten Jahren speziell für die zerstörungsfreie Charakterisierung von Leichtbau-Hochleistungs-Werkstoffen wie Verbund-Werkstoffen und Keramiken entwickelt. Die Technik basiert auf der Refraktion von Röntgenlicht an Grenzflächen zwischen Bereichen unterschiedlicher Elektronendichte wie z.B. Faser- und Matrix-Werkstoff. Auf Grund der kurzen Röntgen-Wellenlänge hat der Brechungsindex einen Wert dicht bei eins, sodass der Streuwinkel nur wenige Bogenminuten beträgt. Der Vorteil der kurzen Wellenlänge besteht jedoch darin, dass Poren und Risse detektiert werden können, deren Größe im Nanometerbereich liegen. Damit kann die Refraktions-Technik zum besseren Verständnis von Mikro- und Submikro-Strukturen in der Materialwissenschaft eingesetzt werden. Mit der hier vorgestellten Refraktions-CT wurden Ermüdungsmechanismen an MMCs, bestehend aus SiC-Faser verstärktem Titan (Ti6242) untersucht. Die Messungen wurden am Röntgen-Messplatz der BAM (BAMline) am Synchrotron-Speicherring-BESSY in Berlin Adlershof durchgeführt.
KW - X-ray refraction
KW - Computed tomography
PY - 2004
DO - https://doi.org/10.3139/120.100592
SN - 0025-5300
VL - 46
IS - 6
SP - 314
EP - 319
PB - Carl Hanser Verlag
CY - München
AN - OPUS4-5870
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Müller, Bernd R.
A1 - Hentschel, Manfred P.
A1 - Harbich, Karl-Wolfram
A1 - Lange, Axel
A1 - Schors, Jörg
T1 - X-ray refraction topography for non-destructive evaluation of advanced materials
T2 - 15th World Conference on Non-Destructive Testing (WCNDT)
CY - Roma, Italy
DA - 2000-10-15
KW - X-ray refraction
PY - 2000
UR - http://www.ndt.net/article/wcndt00/papers/idn257/idn257.htm
SN - 1435-4934
VL - 5
IS - 11
SP - 1
EP - 7(?)
PB - NDT.net
CY - Kirchwald
AN - OPUS4-871
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Müller, Bernd R.
A1 - Hentschel, Manfred P.
A1 - Lange, Axel
A1 - Harwardt, Michael
T1 - Characterization of metal composites by synchrotron-refraction-CT
KW - Synchrotron Refraction CT
PY - 2005
UR - http://www.helmholtz-berlin.de/media/media/oea/web/pr_webseite/druckschriften/berichte/bessy/annualreport2004.pdf#page=483
SN - 0179-4159
SP - 483
EP - 485
PB - Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung
CY - Berlin
AN - OPUS4-7381
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Harwardt, Michael
A1 - Hentschel, Manfred P.
T1 - Sub-micrometer computed tomography at BAMline
PY - 2004
UR - http://www.helmholtz-berlin.de/media/media/oea/web/pr_webseite/druckschriften/berichte/bessy/annualreport2003.pdf#page=321
SN - 0179-4159
SP - 321
EP - 323
PB - Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung
CY - Berlin
AN - OPUS4-3509
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Harwardt, Michael
A1 - Hentschel, Manfred P.
A1 - Illerhaus, Bernhard
A1 - Goebbels, Jürgen
A1 - Bamberg, J.
A1 - Heutling, F.
T1 - 3D Refraction Computed Tomography Applied to Metal Matrix Composites
N2 - For the first time Metal Matrix Composites (MMC) have been investigated by 3D Computed Tomography combined with enhanced interface contrast due to X-ray refraction. X-ray refraction is a relatively new approach for the characterization of advanced materials. The related techniques of Refraction Topography and Refraction Computed Tomography have been developed and applied at our laboratory during the last decade to meet the actual demand for improved nondestructive characterization of high performance composites, ceramics and other low density materials and components. X-ray refraction occurs, when X-rays crosses interfaces of spherical or cylindrical shape (e.g. pores or fibres) in the same way as visible light is refracted by lenses. These X-ray optical effects can be observed at small scattering angles of few minutes of arc as the refractive index n of X-rays is nearly unity (n = 1 10-6). Due to the short X-ray wavelength of about 0.1 nm the technique determines the amount of inner surfaces and interfaces of nanometer dimensions. The technique is expected to solve many problems in understanding the meaning of micro and sub micro structures in materials science. With the results of the CT investigation, some questions could be clarified for a better understanding of fatigue failure mechanisms under cyclic loading conditions. The specimens for the test programme have been provided by MTU Aero Engines. They consist of a titanium matrix (Ti6242) reinforced by SiC fibres (SCS6). The investigations have been performed at the materials research station of BAM (BAMline) at the Synchrotron Facility BESSY in Berlin, Germany.
T2 - 35th International SAMPE technical conference
CY - Dayton, OH, USA
DA - 2003-09-28
KW - Non-Destructive Inspection (NDI)
KW - Characterization
KW - Titanium Metal Matrix Composites (Ti-MMC)
KW - Ti6242
KW - SCS6
PY - 2003
SN - 0-938994-95-6
PB - SAMPE
CY - Covina, Calif.
AN - OPUS4-2780
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kupsch, Andreas
A1 - Hentschel, Manfred P.
A1 - Lange, Axel
A1 - Müller, Bernd R.
T1 - Einfaches Korrigieren des Hinterleuchtens von Röntgendetektoren
N2 - Hinterleuchten stellt eine oft unerkannte Fehlweisung in der radiographischen Abbildung mit Flächendetektoren dar, die durch diffuse Umverteilung der Intensität verursacht wird. Dieser Effekt kann die korrekte Transmissions-Intensität eines Probekörpers gemäß dem Lambert-Beer'schen Gesetz erheblich verfälschen. Hinterleuchten wird sowohl mit Bremsstrahlung von Röntgenröhren als auch mit monochromatischer Synchrotronstrahlung beobachtet. Die fehlerhaft reduzierten Schwächungskoeffizienten von einigen 10 % korrelieren mit der Strahlschwächung und dem direkt bestrahlten Detektorbereich. Für eine einfache numerische Korrektur des Hinterleuchtens werden lediglich integrale Intensitätswerte benötigt.
KW - Hinterleuchten
KW - Röntgendetektor
KW - Fluoreszenzschirm
KW - Radiographie
PY - 2013
DO - https://doi.org/10.3139/120.110478
SN - 0025-5300
VL - 55
IS - 7-8
SP - 1
EP - 5
PB - Hanser
CY - München
AN - OPUS4-28692
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kupsch, Andreas
A1 - Lange, Axel
A1 - Hentschel, Manfred P.
A1 - Müller, Bernd R.
T1 - Improved computed tomography by variable desmearing - Model reconstructions by iterative DIRECTT algorithm
N2 - Die mitunter erhebliche Verschmierung von computertomograpischen Projektionen durch ausgedehnte Strahlenquellen wird durch eine neuartige Entschmierungsprozedur erheblich reduziert, um eine verbesserte Ortsauflösung der Rekonstruktion zu erreichen. Da die Breite der Verschmierungsfunktion der detektornahen und -fernen Objektelemente sich erheblich unterscheiden kann, muss die Entschmierung variabel sein. Im Gegensatz zu einer für alle Voxel-Positionen identischen Entfaltung, also einer grundsätzlich falschen Voraussetzung, wurde eine implizite Entschmierung entwickelt. Die vorab bekannte positionsabhängige Verschmierung wird auf die iterativ wiederholten Projektionen der Teilrekonstruktionen des DIRECTT-Algorithmus angewandt. Die variabel entschmierten Rekonstruktionen aus den Sinogrammen eines Pixelmodells mit Verschmierungen von 1 bis 5 Pixel erreichen eine Ortsauflösung von nahezu einem Pixel.
KW - Computertomographie
KW - Neutronen-Tomographie
KW - Tomographische Rekonstruktionsalgorithmen
PY - 2010
SN - 0025-5300
VL - 52
IS - 6
SP - 394
EP - 400
PB - Hanser
CY - München
AN - OPUS4-21464
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Müller, Bernd R.
A1 - Hentschel, Manfred P.
A1 - Harbich, Karl-Wolfram
A1 - Lange, Axel
A1 - Schors, Jörg
T1 - Charakterisierung von Mikroschäden in polymeren Faserkompositen mittels Röntgen-Refraktions-Topography
T2 - Jahrestagung Zerstörungsfreie Materialprüfung 2001
CY - Berlin, Deutschland
DA - 2001-05-21
PY - 2001
UR - http://www.ndt.net/article/dgzfp01/papers/p49/p49.htm
N1 - Serientitel: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V. – Series title: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V.
IS - 75-CD
PB - DGZfP
CY - Berlin
AN - OPUS4-1298
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Harwardt, Michael
A1 - Hentschel, Manfred P.
ED - Paul Sellin,
T1 - Refraction enhanced micro-CT for non-destructive materials characterization
T2 - IEEE Nuclear Science Symposium
CY - Dresden, Germany
DA - 2008-10-19
KW - Synchrotron
KW - Micro-CT
KW - Refraction
PY - 2008
SN - 978-1-4244-2715-4
SN - 1082-2654
SP - 541
EP - 546
AN - OPUS4-18662
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hentschel, Manfred P.
A1 - Lange, Axel
A1 - Kupsch, Andreas
A1 - Müller, Bernd R.
T1 - Rekonstruktion unvollständiger computertomografischer Modelldatensätze mit Directt-Algorithmus
N2 - Modellrechnungen zur Rekonstruktion unvollständiger computertomographischer Datensätze werden zur Ermittlung der Vorteile des neuen Directt-Algorithmus gegenüber der konventionellen gefilterten Rückprojektion durchgeführt, insbesondere auch zur Vermeidung experimentell begründeter Unwägbarkeiten. Ein entsprechender Bedarf entsteht seitens erweiterter Forschungsaktivitäten und industrieller Bedürfnisse, wo die Rekonstruktion limitierter Messdatensätze von Artefakten dominiert wird. Die bekanntesten Einschränkungen betreffen das Limited-View- und Few-Angles-Problem sowie die ROI-Situation, die jeweils unabhängig voneinander untersucht werden, in der Anwendung jedoch zumeist undefiniert vermischt sind, wie etwa in der Elektronen-Tomografie. Die hochauflösende Rekonstruktion von Einzelpixeln wird durch die Wahl eines kleinen Modells von nur 1012 Pixeln visualisiert und ist ohne Filterung möglich. Rekonstruktionen von 90°-Sektoren oder 50 % -ROI-Querschnitten sind fast ohne Auflösungseinschränkungen realisierbar. Die bisher nicht bekannte Möglichkeit, auch außerhalb der ROI präzise zu rekonstruieren, wurde als "Extended ROI"-Methode erfolgreich erprobt.
KW - Computed tomography
KW - Reconstruction algorithm
KW - Filtering
KW - Limited view
KW - Region of interest
PY - 2010
SN - 0025-5300
VL - 52
IS - 10
SP - 668
EP - 675
PB - Hanser
CY - München
AN - OPUS4-22068
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Harwardt, Michael
A1 - Hentschel, Manfred P.
T1 - Synchrotron Based Micro-CT and Refraction Enhanced Micro-CT of MMC
T2 - International Symposium on NDT in Aerospace
CY - Fürth, Germany
DA - 2008-12-03
KW - X-ray Refraction
KW - Synchrotron Radiation
KW - Computed Tomography
KW - Metal Matrix Composites
KW - Lightweight Materials
KW - Aerospace
PY - 2008
SN - 978-3-940283-12-2
N1 - Serientitel: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V. – Series title: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V.
IS - DGZfP-BB 114 (Poster 10)
SP - 295
EP - 305
PB - DGZfP
CY - Berlin
AN - OPUS4-18607
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Hentschel, Manfred P.
ED - Cohen, L. J.
T1 - Non-Destructive Characterization of High Performance Composites by use of X-Ray Refraction Topography
T2 - 48th International SAMPE symposium and exhibition
CY - Long Beach, CA, USA
DA - 2003-05-11
KW - Non-Destructive Inspection (NDI)
KW - Characterization
KW - Advanced Composite
PY - 2003
SN - 0-938994-94-8
VL - 1
SP - 1203
EP - 1211
PB - SAMPE International Business Office
CY - Covina, Calif.
AN - OPUS4-2542
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Hentschel, Manfred P.
A1 - Kupsch, Andreas
ED - Kastner, J.
T1 - A comfortable procedure for correcting X-ray detector backlight
T2 - Conference on industrial computed tomography
CY - Wels, Austria
DA - 2012-09-19
KW - X-ray detector backlighting
KW - Radiography
KW - Fluorescent screen
KW - Diffuse background
KW - Computed tomography
PY - 2012
SN - 978-3-8440-1281-1
SN - 1610-4773
SP - 151
EP - 157
PB - Shaker
CY - Aachen
AN - OPUS4-26768
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Müller, Bernd R.
A1 - Hentschel, Manfred P.
A1 - Lange, Axel
T1 - Non-destructive evaluation of advanced materials by synchrotron radiation refraction topography
PY - 2002
UR - http://www.helmholtz-berlin.de/media/media/oea/web/pr_webseite/druckschriften/berichte/bessy/annualreport2001.pdf#page=233
SN - 0179-4159
SP - 233
EP - 234
PB - Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung
CY - Berlin
AN - OPUS4-1326
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Harwardt, Michael
A1 - Hentschel, Manfred P.
T1 - X-Ray refraction computed tomography for NDE of lightweight materials
T2 - Deutsche Tagung für Forschung mit Synchrotronstrahlung, Neutronen und Ionenstrahlen an Großgeräten 2006 (SNI2006)
CY - Hamburg, Germany
DA - 2006-10-04
PY - 2006
AN - OPUS4-15836
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Hentschel, Manfred P.
ED - Green, R. E.
ED - Djordjevic, B. B.
ED - Hentschel, M. P.
T1 - Synchrotron Radiation Refraction Topography
PY - 2003
SN - 3-540-40154-7
SP - 167
EP - 176
PB - Springer
CY - Berlin
AN - OPUS4-2765
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Lange, Axel
A1 - Kupsch, Andreas
A1 - Hentschel, Manfred P.
A1 - Müller, Bernd R.
T1 - DIRECTT-Rekonstruktionen im Vergleich zur gefilterten Rückprojektion
N2 - Anhand von computertomografischen Messungen und Modellrechnungen werden DIRECTT-Rekonstruktionen im Vergleich mit gefilterten Rückprojektionen bewertet. Dazu wird die Rekonstruktionsqualität mittels einer zirkular erweiterten Modulations-Transfer-Funktion (MTF) und mit integralen Kenngrößen im Radon- und im Ortsraum verglichen. Zur Überprüfung der Rekonstruktionsgenauigkeit experimenteller Daten werden Mustermessungen einfacher Probengeometrien unter definierten physikalischen Bedingungen durchgeführt. Diese beinhalten die Monochromasie, die Unterdrückung von Kantenartefakten und die radiometrische Intensitätsbestimmung. Für die Qualität der Rekonstruktionen mittels DIRECTT erweisen sich sowohl unterschiedliche Rekonstruktionsfilter als auch der Verzicht auf jede Filterung als unerheblich, im Gegensatz zur gefilterten Rückprojektion.
KW - Computertomografie
KW - Gefilterte Rückprojektion
KW - Rekonstruktionsalgorithmen
KW - Iterative Rekonstruktion
KW - DIRECTT
KW - Konvergenz
KW - Modulations-Transfer-Funktion (MTF)
PY - 2014
UR - http://www.hanser-elibrary.com/doi/pdf/10.3139/120.110610
SN - 0025-5300
VL - 56
IS - 9
SP - 709
EP - 715
PB - Hanser
CY - München
AN - OPUS4-31378
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kupsch, Andreas
A1 - Lange, Axel
A1 - Schors, Jörg
A1 - Müller, Bernd R.
A1 - Harwardt, Michael
T1 - Vom Synchrotron ins Labor - Konversion von Einkristall-Techniken für Röntgenröhren
KW - Einkristall
KW - Röntgenbeugung
KW - Synchrotron
KW - Divergenz
PY - 2008
SN - 0025-5300
VL - 50
IS - 10
SP - 580
EP - 587
PB - Hanser
CY - München
AN - OPUS4-18248
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Müller, Bernd R.
A1 - Hentschel, Manfred P.
A1 - Lange, Axel
T1 - SYRTOPO - Materialcharakterisierung an der BAMline
N2 - Einleitung
Die Bundesanstalt für Materialforschung und -prüfung (BAM) hat im Synchrotronstrahlungslabor BESSY (im Wissenschafts- und Technologiezentrum Berlin-Adlershof) ein Röntgen-Strahlrohr (BAMline) sowie einen Messplatz für die zerstörungsfreie Materialcharakterisierung aufgebaut. Der Messplatz erlaubt die Untersuchung mit monochromatischer Röntgenstrahlung im Energiebereich von 5keV bis 60keV mit hohem Photonenfluß. Seit Anfang 2001 läuft der Probebetrieb zur Optimierung der Strahlungsquelle sowie des experimentellen Aufbaus.
Die Besonderheiten der BAMline im Vergleich zu Laboröntgenquellen sind der hohe Photonenfluss bei freier Wahl der Photonenenergie sowie die Polarisationseigenschaften und die außerordentliche Parallelität der Strahlung bei großem Strahlungsquerschnitt. Dies ermöglicht Refraktionstopogramme für Metall-Matrix-Komposite (MMC) in relativ kurzer Zeit, mit einer lateralen Ortsauflösung von 10µm, zu messen.
Das neuartige ZfP-Verfahren der Röntgen-Refraktions-Topograhy wurde an anderer Stelle ausführlich beschrieben [1,2]. Es nutzt die Messtechnik der traditionellen Kleinwinkelstreuung auf unkonventionelle Weise, und wurde in den letzten zehn Jahren in unserem Labor entwickelte und an die fortgeschrittenen Anforderungen für die zerstörungsfreie Charakterisierung von neuartigen Werkstoffen wie faserverstärkten Kompositen und Keramiken angepasst. Das Verfahren basiert auf dem Brechungseffekt von Röntgenstrahlen. Auf Grund der kurzen Wellenlänge der Röntgenstrahlen (l » 0.1nm) können innere Oberflächen sowie Grenzflächenkonzentrationen von Nanometer Große detektiert werden, so dass mit Hilfe dieser Technik sehr leicht Partikel, Risse und Porengrößen im Sub-Mikrometer-Bereich gemessen werden können, ohne dabei die Proben zu zerstören, wie es bei mikroskopischen Techniken notwendig ist.
Anwendungsfelder dieser Untersuchungsmethode sind z.B. die Erkennung von Faser-Matrix-Enthaftung nach Schlageinwirkung sowie Rissbildung durch Alterung und Herstellung bei faserverstärkten Kompositen.
T2 - Jahrestagung Zerstörungsfreie Materialprüfung 2002
CY - Weimar, Deutschland
DA - 2002-05-06
PY - 2002
UR - http://www.ndt.net/article/dgzfp02/papers/v16/v16.htm
SN - 3-931381-39-0
N1 - Serientitel: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V. – Series title: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V.
IS - 80-CD
SP - 1(?)
EP - 6(?)
PB - DGZfP
CY - Berlin
AN - OPUS4-2793
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Müller, Bernd R.
A1 - Harwardt, Michael
A1 - Hentschel, Manfred P.
A1 - Lange, Axel
A1 - Alpern, P.
A1 - Tilgner, R.
T1 - Sichere Automobil Elektronik durch nanogenaues Synchrotron-Prüfverfahren
T2 - DGZfP Jahrestagung 2007
CY - Fürth, Deutschland
DA - 2007-05-14
KW - Synchrotron Laue Contrast Radiography
PY - 2007
SN - 978-3-931381-98-1
SP - 1
EP - 8
PB - DGZfP
CY - Berlin
AN - OPUS4-15837
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schors, Jörg
A1 - Hentschel, Manfred P.
A1 - Harbich, Karl-Wolfram
A1 - Lange, Axel
A1 - Müller, Bernd R.
T1 - Röntgen-Topographie mit Klein- und Weitwinkel-Streuung und Röntgenrefraktions-Computertomographie
KW - Röntgen-Streuung
KW - Materialcharakterisierung
KW - Komposite
KW - Keramik
KW - Risse
KW - Computertomographie
PY - 2003
SN - 0948-5112
IS - 86
SP - 11 Seiten
PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung
CY - Berlin
AN - OPUS4-2652
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hentschel, Manfred P.
A1 - Kupsch, Andreas
A1 - Lange, Axel
A1 - Müller, Bernd R.
T1 - Refraktions-Interface-Radiographie
N2 - Nanoskalige Strukturen und Grenzflächen bestimmen zunehmend die
Funktionalität moderner Materialien und Bauteile und erfordern ihre zerstörungsfreie Charakterisierung mit angepasster Ortsauflösung. Dazu sind wegen der passenden Wellenlängen Röntgen-Refraktionsverfahren einsetzbar. Die resultierende Kleinwinkelstreuung verursacht lokal große Intensitäten, die durch Umlagerung oder Fokussierungseffekte das Primärstahlniveau übersteigen können. Mit monochromatischer Synchrotronstrahlung an homogenen Musterproben einfacher Geometrien (Platten und Zylinder) wird die Dominanz der Refraktionsintensität gegenüber der Totalreflexion dargestellt. Der Refraktionseffekt kann für Einstrahlwinkel bis zu einigen Grad genutzt werden; die typischen Streuwinkel liegen in der Größenordnung von Bogensekunden bis -minuten. Darüber hinaus wird die Bestimmung der inneren Oberflächen, Poren und Nanorisse auch orientierungsspezifisch mit Laborausrüstungen demonstriert.
T2 - DGZfP-Jahrestagung 2013
CY - Dresden, Germany
DA - 06.05.2013
KW - Röntgenrefraktion
KW - Kleinwinkelstreuung
KW - Refraktionstopographie
KW - Nanostrukturen
PY - 2013
SN - 978-3-940283-49-8
IS - Mo.2.A.2
SP - 1
EP - 10
AN - OPUS4-28691
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rack, A.
A1 - Zabler, S.
A1 - Müller, Bernd R.
A1 - Riesemeier, Heinrich
A1 - Weidemann, Gerd
A1 - Lange, Axel
A1 - Goebbels, Jürgen
A1 - Hentschel, Manfred P.
A1 - Görner, Wolf
T1 - High resolution synchrotron-based radiography and tomography using hard X-rays at the BAMline (BESSY II)
N2 - The use of high brilliance and partial coherent synchrotron light for radiography and computed tomography (CT) allows to image micro-structured, multi-component specimens with different contrast modes and resolutions up to submicrometer range. This is of high interest for materials research, life science and non-destructive evaluation applications. An imaging setup for microtomography and radiography installed at BESSY II (a third generation synchrotron light source located in Berlin, Germany) as part of its first hard X-ray beamline (BAMline) can now be used for absorption, refraction as well as phase contrast dedicated to inhouse research and applications by external users. Monochromatic synchrotron light between 6 keV and 80 keV is attained via a fully automated double multilayer monochromator. For imaging applications the synchrotron beam transmitted by the sample is converted with a scintillator into visible light. By use of microscope optics this luminescence image is then projected onto, e.g., a CCD chip. Several scintillating materials are used in order to optimise the performance of the detector system. Different optical systems are available for imaging ranging from a larger field of view and moderate resolutions (macroscope up to 14 mm x 14 mm field of view) to high resolution (microscope down to 0.35 μm pixel size), offering magnifications from 1.8× to 40×. Additionally asymmetric cut Bragg crystals in front of the scintillator can be used for a further magnification in one dimension by a factor of about 20. Slow and fast cameras are available, with up to 16 bit dynamic range. We show the suitability of the setup for numerous applications from materials research and life science.
KW - Microtomography
KW - Non-destructive evaluation
KW - Synchrotron instrumentation
KW - Coherent imaging
KW - X-ray refraction
KW - Phase contrast
KW - Holotomography
KW - Synchrotron-CT
KW - Scintillator
KW - Bragg magnification
PY - 2008
DO - https://doi.org/10.1016/j.nima.2007.11.020
SN - 0168-9002
SN - 0167-5087
VL - 586
IS - 2
SP - 327
EP - 344
PB - North-Holland
CY - Amsterdam
AN - OPUS4-17738
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Harwardt, Michael
T1 - Synchrotron-Refraktions-Computertomografie - eine neue Methode zur Erkennung von Grenzflächen
N2 - Röntgenstrahlung eignet sich besonders gut zur zerstörungsfreien Charakterisierung von Werkstoffen. Mit ihrer Hilfe lassen sich z. B. Risse und Poren in Werkstoffen erkennen. Die Risserkennbarkeit ist jedoch von der Rissgröße im Vergleich zum Auflösungsvermögen des Detektors abhängig. Risse, Poren oder Einschlüsse können in Radiogrammen nur dann erkannt werden, wenn sie größer sind als das Detektorelement, das die Röntgenstrahlen registriert. Das hier vorgestellte neuartige Synchrotron-Refraktions-Computertomografie-Verfahren ist jedoch in der Lage, auch Risse zu erkennen, deren Größe weit unterhalb des Auflösungsvermögens des Detektors liegt. Das Verfahren basiert auf dem bisher wenig genutzten Phänomen der Kleinwinkelstreuung durch Brechung von Röntgenstrahlen an den inneren Grenzflächen mikroskopisch strukturierter Objekte. Durch den Vergleich zwischen absorptionsbasierter und refraktionsbasierter Computertomografie-Untersuchungen mit Synchrotronstrahlung an einer geschädigten Faserverbundprobe wird das Potenzial der Synchrotron-Refraktions-Computertomografie demonstriert.
KW - Synchrotronstrahlung
KW - Refraktion
KW - Diffraktion
KW - Kleinwinkelstreuung
KW - Materialcharakterisierung
KW - Zerstörungsfrei
PY - 2008
SN - 0025-5300
VL - 50
IS - 10
SP - 588
EP - 594
PB - Hanser
CY - München
AN - OPUS4-18657
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Harwardt, Michael
A1 - Hentschel, Manfred P.
A1 - Hamm, B.
A1 - Rogalla, P.
A1 - Diederichs, G.
A1 - Issever, A.S.
T1 - First Synchrotron Refraction CT of Cartilage
KW - X-ray Refraction
KW - Computed Tomography
KW - DEI
KW - Cartilage
PY - 2008
UR - http://www.helmholtz-berlin.de/media/media/oea/web/pr_webseite/druckschriften/berichte/bessy/annual_report_2007-v2.pdf#page=292
SN - 0179-4159
SP - 292
EP - 296
PB - Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung
CY - Berlin
AN - OPUS4-17661
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Hentschel, Manfred P.
A1 - Kupsch, Andreas
T1 - A comfortable procedure for correcting X-ray detector backlight
N2 - A novel approach is suggested to strongly suppress artifacts in radiography and computed tomography caused by the effect of diffuse background signals 'backlighting' of 2D X-ray detectors. Depending on the detector geometry the mechanism may be different. Either based on the optical scattering of the fluorescent screen materials into the optical detection devices or Compton or X-ray fluorescence scattering by the detector components. Consequently, these erroneous intensity portions result in locally different violations of Lambert Beer's law in single projections (radiographs) as a function of the detector area coverage and the magnitude of the attenuation. The absorption of multiple metal sheets is investigated by monochromatic synchrotron radiation, thus excluding beam hardening. The proposed correction procedure simply requires the individual subtraction of one and the same fraction of the primary and transmitted mean intensity, as a constant (non-local) scattering mechanism is assumed.
KW - X-ray detector backlighting
KW - Radiography
KW - Fluorescent screen
KW - Diffuse background
KW - Computed tomography
PY - 2013
DO - https://doi.org/10.1088/1742-6596/425/19/192015
SN - 1742-6588
SN - 1742-6596
VL - 425
IS - 19
SP - 192015-1
EP - 192015-4
PB - IOP Publ.
CY - Bristol, UK
AN - OPUS4-28262
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Hentschel, Manfred P.
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Wald, Oliver
T1 - Quantitative X-ray Determination of CFRP Micro Structures
T2 - International Symposium on NDT in Aerospace
CY - Fürth, Germany
DA - 2008-12-03
KW - Neutronen-Radiographie
KW - Neutronen-Tomographie
KW - Tomographische Rekonstruktionsalgorithmen
KW - Brennstoffzellen
KW - In-Situ Radiologie
PY - 2008
SN - 978-3-940283-12-2
N1 - Serientitel: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V. – Series title: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V.
IS - DGZfP-BB 114 (X-Ray/Lecture 13)
SP - 89
EP - 98
PB - DGZfP
CY - Berlin
AN - OPUS4-18606
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Hentschel, Manfred P.
A1 - Lange, Axel
A1 - Müller, Bernd R.
A1 - Schors, Jörg
A1 - Harbich, Karl-Wolfram
T1 - Röntgen-Refraktions-Computer-Tomographie
N2 - Für die Charakterisierung Neuer Werkstoffe, vornehmlich Nichtmetalle, hat sich das Verfahren der Röntgen-Refraktions-Topographie bewährt. Es handelt sich phänomenologisch um eine Technik der Röntgen-Kleinwinkel-Streuung mit Probekörper-Abtastung bei fest vorgewähltem Streuwinkel. Gegenüber der klassischen Beugungstheorie dominieren jedoch bei der Streuung an Strukturen oberhalb von 0.3 µm Größe röntgenoptische Brechungseffekte. Detektierbar sind damit innere Ober- und Grenzflächen, insbesondere Mikrorisse unterhalb der lichtmikroskopischen Erkennbarkeit. Da es sich hierbei um eine Durchstrahlungs-Technik handelt, überlagern jedoch die Strukturen zu einer Projektion, analog zu den radiographischen Verfahren.
Um auch Informationen entlang der Durchstrahlungs-Richtung in der Tiefe des Probekörpers zu erhalten, wird unter kleinen Streuwinkeln die Computer-Tomographie durchgeführt, im ersten Ansatz mit nur zwei Meßkanälen, jeweils für die Messung der Absorptions- und der Refraktions-Intensität. Dazu werden nacheinander 360 Linear-Scans nach Drehung von jeweils 1° aufgenommen. Die Intensitätswerte werden nach den Regeln der fouriergefilterten Rückprojektion zu Computer-Tomogrammen verarbeitet.
Die Ergebnisse visualisieren die Anordnung von Grenzflächen und innere Oberflächen, die sich für zahlreiche nichtmetallische Werkstoffe, vor alllem im Transportmittel-Leichtbau als relevante Mikrostrukturen für das Versagens-Verhalten und die Werkstoff-Optimierung eignen. Zum Vergleich entstehen aus den simultanen Absorptionsmessungen gleichzeitig die klassischen Computer-Tomogramme, die ausschließlich Dichteänderungen anzeigen.
T2 - Jahrestagung Zerstörungsfreie Materialprüfung 1999
CY - Celle, Deutschland
DA - 1999-05-10
KW - Röntgentomographie
KW - Röntgen-Refraktions-Computer-Tomographie
PY - 1999
UR - http://www.ndt.net/abstract/dgzfp99/data/40.htm
SN - 3-931381-27-7
VL - 1
IS - 68
SP - 361
EP - 369
PB - DGZfP
CY - Berlin
AN - OPUS4-715
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Harwardt, Marco
A1 - Hentschel, Manfred P.
A1 - Illerhaus, Bernhard
A1 - Goebbels, Jürgen
T1 - Synchrotron Refraction CT and Synchrotron Bragg Magnification CT for NDE
T2 - International Symposium on Digital industrial Radiology and Computed Tomography (DIR 2007)
CY - Lyon, France
DA - 2007-06-25
KW - X-ray Refraction
KW - Diffraction Enhanced Imaging (DEI)
KW - Bragg Magnification
KW - Synchrotron Radiation
KW - Computed Tomography (CT)
KW - Metal Matrix Composites (MMC)
KW - Lightweight Materials
KW - Aerospace
PY - 2007
IS - CD-ROM
SP - 1
EP - 8
CY - Lyon, France
AN - OPUS4-16366
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Hentschel, Manfred P.
A1 - Müller, Bernd R.
A1 - Harwardt, Michael
A1 - Lange, Axel
T1 - Synchrotron-Refraktions-Computer Tomographie für die Materialforschung
T2 - DGZfP Jahrestagung
CY - Rostock, Deutschland
DA - 2005-05-02
KW - Computer-Tomographie
KW - Synchrotronstrahlung
KW - Refraktionskontrast
KW - Bragg-Vergrößerung
PY - 2005
SN - 3-931381-64-1
N1 - Serientitel: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V. – Series title: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V.
IS - 94-CD
SP - 1(?)
EP - 7(?)
PB - DGZfP
CY - Berlin
AN - OPUS4-11698
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Hentschel, Manfred P.
A1 - Harbich, Karl-Wolfram
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Schors, Jörg
A1 - Wald, Oliver
ED - Gerhard Busse,
ED - Danny Van Hemelrijck,
ED - Igor Solodov,
ED - Anastasopoulos, Athanasios
T1 - NDE of micro structured materials by X-ray diffraction and refraction topography
T2 - 4th International Conference of Emerging Technologies in Non-Destructive Testing (ETNDT 4)
CY - Stuttgart, Germany
DA - 2007-04-02
KW - Nondestructive testing
KW - X-ray scattering
KW - X-ray topography
KW - Computed topography
KW - Synchrotron refraction computed tomography
KW - Structure property relations
KW - Composite damaging
KW - Ceramics
KW - Foams
PY - 2007
SN - 978-0-415-46476-5
SP - 15
EP - 22
PB - Taylor & Francis
CY - London, UK
AN - OPUS4-17561
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Kupsch, Andreas
A1 - Lange, Axel
A1 - Hentschel, Manfred P.
A1 - Bruno, Giovanni
A1 - Onel, Yener
A1 - Wolk, Thomas
A1 - Staude, Andreas
A1 - Ehrig, Karsten
A1 - Müller, Bernd R.
T1 - Evaluating porosity in cordierite diesel particulate filter materials: advanced X-ray techniques and new statistical analysis methods
T2 - ECNDT 2014 - 11th European conference on non-destructive testing
CY - Prague, Czech Republic
DA - 2014-10-06
KW - Porous ceramics
KW - Diesel particulate filters
KW - Pore orientation
KW - X-ray computed tomography
KW - X-ray refraction
KW - DIVA algorithm
KW - Phase contrast
KW - Edge artefact
KW - Soft matter radiography
KW - Wavelet transform
KW - Huygens elementary waves
PY - 2014
SN - 978-80-214-5018-9
SP - 1
EP - 8(?)
AN - OPUS4-31973
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Müller, Bernd R.
A1 - Léonard, Fabien
A1 - Lange, Axel
A1 - Kupsch, Andreas
A1 - Bruno, Giovanni
T1 - X-ray refraction techniques for fast, high-resolution microstructure characterization and non-destructive testing of lightweight composites
N2 - X-ray refraction is based on optical deflection of X-rays, similar to the well-known small angle X-ray scattering, but hundreds of times more intense, thus enabling shorter measurement time. We show that X-ray refraction techniques are suitable for the detection of pores, cracks, and in general defects. Indeed, the deflected X-ray intensity is directly proportional to the internal specific surface (i.e., surface per unit volume) of the objects. Although single defects cannot be imaged, the presence of populations of those defects can be detected even if the defects have sizes in the nanometer range.We present several applications of X-ray refraction techniques to composite materials:- To visualize macro and microcracks in Ti-SiC metal matrix composites (MMC);- To correlate fatigue damage (fibre de-bonding) of carbon fibre reinforced plastics (CFRP) to X-ray refraction intensity;- To quantify the impact damage by spatially resolved single fibre de-bonding fraction as a function of impact energy in CFRP laminates.An example of classic high-resolution computer tomography of an impact-damaged CFRP will also be presented, as a benchmark to the present state-of-the-art imaging capabilities. It will be shown that while (absorption) tomography can well visualize and quantify delamination, X-ray refraction techniques directly yield (spatially resolved) quantitative information about fibre de-bonding, inaccessible to absorption tomography.
KW - X-ray
KW - Synchrotron radiation
KW - Refraction
KW - Metal matrix composites
KW - Delamination
KW - Fiber de-bonding
PY - 2015
DO - https://doi.org/10.4028/www.scientific.net/MSF.825-826.814
SN - 0255-5476
VL - 825-826
SP - 814
EP - 821
PB - Trans Tech Publications
CY - Aedermannsdorf, Switzerland
AN - OPUS4-33265
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Bruno, Giovanni
A1 - Ehrig, Karsten
A1 - Haarring, Holger
A1 - Harwardt, Michael
A1 - Hentschel, Manfred P.
A1 - Illerhaus, Bernhard
A1 - Kupsch, Andreas
A1 - Lange, Axel
A1 - Meinel, Dietmar
A1 - Müller, Bernd R.
A1 - Onel, Yener
A1 - Staude, Andreas
A1 - Wolk, Thomas
T1 - Industrial and synchrotron X-ray CT applications for materials characterisation
N2 - The combination of tomographic, microstructural data with other experimental techniques and with modeling is paramount, if we want to extract the maximum amount of information on material and component properties. In particular, quantitative image analysis, statistical approaches, direct discretization of tomographic reconstructions represent concrete possibilities to extend the power of the tomographic 3D representation to insights into the material and component performance. This logic thread holds equally for industrial and academic research, and valorizes expensive experiments such as those carried out at synchrotron sources, which cannot be daily repeated. We shall show a few examples of possible use of X-ray tomographic data for quantitative assessment of damage evolution and microstructural properties, as well as for non-destructive testing. We will also show how X-ray refraction computed tomography (CT) can be highly complementary to classic absorption CT, being sensitive to internal interfaces.
T2 - iCT Conference 2014 - Conference on industrial computed tomography
CY - Wels, Austria
DA - 25.02.2014
KW - X-ray absorption and refraction CT
KW - Quantitative image analysis
KW - Statistical analysis
KW - Complex microstructure
PY - 2014
SN - 978-3-8440-2557-6
SP - 15
EP - 31
PB - Shaker
CY - Aachen
AN - OPUS4-30484
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Hentschel, Manfred P.
A1 - Kupsch, Andreas
T1 - Numerische Korrektur des Hinterleuchtens von Röntgendetektoren
N2 - Eine neuartige Korrektur artefaktisch gemessener Intensitäten von Röntgenflachdetektoren wird vorgeschlagen. Die betrachteten Artefakte betreffen eine diffuse Umverteilung der Intensität und führen zu beträchtlichen Verfälschungen der wahren Schwächung und verletzen mithin das Lambert-Beer'sche Gesetz.
Sie werden sowohl in Laborexperimenten mit Röntgenröhren (polychromatische Einstrahlung) als auch mit monochromatischer Synchrotronstrahlung bei Einsatz indirekt konvertierender Detektionssysteme (Fluoreszenzschirm, Optik, CCD-Chip) beobachtet.
Dieser Effekt wird als Hinterleuchten bezeichnet.
In der vorgestellten Studie werden mittels wohldefinierter Randbedingungen Gesetzmäßigkeiten des Hinterleuchtens untersucht: durch Einsatz monochromatischer Strahlung können Aufhärtungseffekte als Ursache ausgeschlossen werden. Das Hinterleuchten ist umso stärker ausgeprägt, je weniger Detektorfläche vom Objekt abdeckt wird und je stärker das Objekt schwächt. Mit Blick auf Tomographien ergibt sich eine Modulation der 'Dichte' als Funktion des Projektionswinkels, deren Amplitude mit dem Objektumfang steigt (Dynamik).
Der isotrope und homogene Ansatz zur numerischen Korrektur macht lediglich Gebrauch von Intensitätsmittelwerten und stellt die Gültigkeit des Schwächungsgesetzes in modifizierter Form wieder her.
T2 - DACH-Jahrestagung 2012
CY - Graz, Austria
DA - 17.09.2012
KW - Röntgendetektor
KW - Hinterleuchten
PY - 2012
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-277372
SN - 978-3-940283-44-3
IS - DGZfP-BB 136
SP - P 13 / Mo.4.B, 1
EP - 7
AN - OPUS4-27737
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Lackmann, C.
A1 - Velki, M.
A1 - Šimić, A.
A1 - Müller, Axel
A1 - Braun, U.
A1 - Ečimović, S.
A1 - Hollert, H.
T1 - Two types of microplastics (polystyrene-HBCD and car tire abrasion) affect oxidative stress-related biomarkers in earthworm Eisenia andrei in a time-dependent manner
N2 - Microplastics are small plastic fragments that are widely distributed in marine and terrestrial environments. While the soil ecosystem represents a large reservoir for plastic, research so far has focused mainly on the impact on aquatic ecosystems and there is a lack of information on the potentially adverse effects of microplastics on soil biota. Earthworms are key organisms of the soil ecosystem and are due to their crucial role in soil quality and fertility a suitable and popular model organism in soil ecotoxicology.
Therefore, the aim of this study was to gain insight into the effects of environmentally relevant concentrations of microplastics on the earthworm Eisenia andrei on multiple levels of biological organization after different exposure periods. Earthworms were exposed to two types of microplastics: (1) polystyrene-HBCD and (2) car tire abrasion in natural soil for 2, 7, 14 and 28 d. Acute and chronic toxicity and all subcellular investigations were conducted for all exposure times, avoidance behavior assessed after 48 h and reproduction after 28 d. Subcellular endpoints included enzymatic biomarker responses, namely, carboxylesterase, glutathione peroxidase, acetylcholinesterase, glutathione reductase, glutathione S-transferase and catalase activities, as well as fluorescence-based measurements of oxidative stress-related markers and multixenobiotic resistance activity. Multiple biomarkers showed significant changes in activity, but a recovery of most enzymatic activities could be observed after 28 d. Overall, only minor effects could be observed on a subcellular level, showing that in this exposure scenario with environmentally relevant concentrations based on German pollution levels the threat to soil biota is minimal. However, in areas with higher concentrations of microplastics in the environment, these results can be interpreted as an early warning signal for more adverse effects. In conclusion, these findings provide new insights regarding the ecotoxicological effects of environmentally relevant concentrations of microplastics on soil organisms.
KW - Microplastics
KW - Earthworms
KW - Toxicity
KW - Biomarker
KW - oxidative stress
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-545423
DO - https://doi.org/10.1016/j.envint.2022.107190
VL - 163
SP - 1
EP - 12
PB - Elsevier Ltd.
AN - OPUS4-54542
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Bruno, Giovanni
A1 - Hentschel, Manfred P.
A1 - Onel, Yener
A1 - Lange, Axel
A1 - Kupsch, Andreas
A1 - Wolk, Thomas
A1 - Staude, Andreas
A1 - Ehrig, Karsten
A1 - Müller, Bernd R.
T1 - Bewertung von Porositätsparametern in Cordierit-Diesel-Partikelfilter-Materialien mit fortgeschrittenen Röntgenverfahren und statistischer Analyse
N2 - Bikontinuierliche poröse Keramiken für Filteranwendungen weisen eine komplizierte Mikrostruktur auf, in der Poren und Festkörperphase 'vermischt' sind. Mechanische, thermische sowie Filtereigenschaften können nur präzise bestimmt werden, wenn die Morphologie beider Phasen quantitativ angegeben werden kann. Hier werden unter Anwendung von 3D Computertomographie (CT) und verschiedenen Techniken, die auf der Röntgenrefraktion basieren, die Porosität und die Porenorientierung in keramischen Cordierit-Dieselpartikelfiltern bewertet. Dabei werden zur Auswertung der Tomogramme die Fouriertransformierten sowie eine neu entwickelte richtungssensitive Bildanalyse (DIVA, directional interface variance analysis) angewandt. Sowohl die genannten Messtechniken als auch der statistische Ansatz gestatten die Extraktion optional ortsaufgelöster oder gemittelter Werte. Es ergeben sich sehr gute Übereinstimmungen der experimentell ermittelten Porositätswerte mit Ergebnissen aus Quecksilberintrusionsversuchen als auch der ermittelten Porenorientierung im Vergleich zu publizierten Angaben zur kristallographischen Textur. Dies legt den Schluss nahe, dass die Kenntnis der Grenzflächen (zwischen Poren und Materie) genügt, die morphologischen Eigenschaften solcher Materialien hinreichend zu beschreiben.
T2 - DGZfP-Jahrestagung 2014
CY - Potsdam, Germany
DA - 26.05.2014
KW - Cordierit
KW - Poröse Keramik
KW - Porenorientierung
KW - Röntgenrefraktion
KW - Computer-Tomographie
KW - 3D-Mikrostruktur
PY - 2014
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-312946
SN - 978-3-940283-61-0
VL - 148
SP - 1
EP - 8
PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP)
CY - Berlin
AN - OPUS4-31294
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Kupsch, Andreas
A1 - Hentschel, Manfred P.
A1 - Lange, Axel
A1 - Bruno, Giovanni
A1 - Müller, Bernd R.
T1 - Direkte Röntgenrefraktion an Mikrostrukturen
N2 - Die durch Brechung an Mikrostrukturen abgelenkte Röntgenstrahlung wird direkt zweidimensional abgebildet. Dazu werden Modellproben einfacher Geometrie (Fasern, Kapillaren, monodisperse Nano- und Mikropartikel) mit einem auf 50 µm kollimierten Synchrotronstrahl (20 keV) gescannt. Die nach den Regeln der geometrischen Optik an prismatischen und linsenartigen Grenzflächen abgelenkte Strahlung wird in etwa 3 Metern Entfernung von einem Flächendetektor mit 7 µm Ortsauflösung zusätzlich zu der ungestörten Resttransmission des Primärstrahls registriert. In der Abfolge der Radiogramme werden die lokalen Orientierungsänderungen der Probekörper-Grenzflächen bei deren Abtastung mit wenigen Mikrometern Schrittweite bildhaft verfolgt. Mit der hier erreichten Winkelauflösung von etwa 3 Bogensekunden (Streuvektor-Inkremente Δk = 10-3nm-1) kann bei 50 µm Ortsauflösung das Materialvolumen bezüglich innerer Grenzflächen mit Nanometer-Separation auch bei hohen Abtastraten unterhalb einer Sekunde pro Bild charakterisiert werden.
T2 - DGZfP-Jahrestagung 2014
CY - Potsdam, Germany
DA - 26.05.2014
KW - Computertomographie (CT)
KW - Rekonstruktionsalgorithmus
KW - DIRECTT
KW - Missing wedge
KW - Statistische Bewertung
PY - 2014
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-312931
UR - http://www.ndt.net/article/dgzfp2014/papers/di1b2.pdf
SN - 978-3-940283-61-0
IS - DGZfP-BB 148
SP - Di.1.B.2, 1
EP - 9
PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP)
CY - Berlin
AN - OPUS4-31293
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Shashev, Yury
A1 - Kupsch, Andreas
A1 - Lange, Axel
A1 - Evsevleev, Sergei
A1 - Britzke, Ralf
A1 - Bruno, Giovanni
A1 - Müller, Bernd R.
T1 - Talbot-Lau Röntgen-Interferometrie für die zerstörungsfreie Prüfung
N2 - Im vergangenen Jahrzehnt sind gitterinterferometrische Röntgenabbildungen zunehmend in den Fokus des Interesses gerückt. Sie sind insbesondere dann Vorteil, wenn der in der Standardradiographie erreichbare Kontrast nicht genügt, schwach absorbierende Mikro- und Nanostrukturen abzubilden.
Auf Kosten mehrerer Aufnahmen gestattet die Talbot-Lau Gitterinterferometrie, die Beiträge aus Absorption, Refraktion und (refraktiver) Streuung zu trennen. Dazu werden die Störungen der Interferenzmuster von Phasengittern ausgewertet. Im Gegensatz zu einer Vielzahl anderer refraktionsbasierter Abbildungsmethoden kann diese Technik mit konventionellen Röntgenröhren (mit divergenter, polychromatischer Strahlung) angewendet werden. Damit ist die Technik geeignet, typische ZfP-Fragestellungen zu lösen.
Hier stellen wir Untersuchungen zur Effizienz von Phasengittern vor. Die Visibilität (d.h. die Höhe der Oszillation im Interferenzmuster) wird als Funktion verschiedener geometrischer Parameter verfolgt. Eine Rotation um die Achse parallel zu den Gitterstegen ändert die Form des Gitterprofils (d.h. die Verteilung der Phasenschiebungen). Die kontinuierliche Variation des Winkels und des Detektionsabstandes führt zur Identifikation von ausgezeichneten Kombinationen mit maximaler Visibilität, wobei die Abstände deutlich geringer sind als im Standardaufbau mit senkrechter Gitterbestrahlung.
Unsere Studie umfasst Simulationen für monochromatische Quelle und den Vergleich zu experimentellen Ergebnissen mit der Synchrotronstrahlung.
In der Literatur wurden die Vorteile der Talbot-Lau Interferometrie für die zerstörungsfreie Prüfung von Faserkompositen und Verbundwerkstoffen demonstriert. Hier werden als Beispiele Messungen an Aluminiumtitanat (Al2TiO5) Pulver gezeigt.
T2 - DGZfP 2017
CY - Koblenz, Germany
DA - 22.05.2017
KW - Gitterinterferometrische Röntgenabbildung
KW - Phasengitter
KW - Talbot-Lau Interferometrie
KW - Zerstörungsfreie Prüfung
PY - 2017
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-404691
SP - 1
EP - 10
PB - DGZfP
AN - OPUS4-40469
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Shashev, Yury
A1 - Kupsch, Andreas
A1 - Lange, Axel
A1 - Britzke, Ralf
A1 - Bruno, Giovanni
A1 - Müller, Bernd R.
A1 - Hentschel, M. P.
T1 - Talbot- Lau interferometry with a non- binary phase grating for non-destructive testing
N2 - Grating interferometric set-ups have been established in the last decade. They are promising candidates to obtain enhanced image contrast from weakly absorbing micro and nano structures. They are based on X-ray refraction and near-field diffraction using the Talbot effect.
At the expense of taking multiple images, Talbot-Lau grating interferometry allows separating the absorption, refraction, and scattering contributions by analysing the disturbances of a phase grating interference pattern. Contrary to other refraction enhanced methods, this technique can be applied using conventional X-ray tubes (divergent, polychromatic source). This makes it attractive to solve typical non-destructive testing problems.
We investigated the efficiency of phase gratings, i.e. the visibility (the amplitude of oscillations) upon variation of propagation distance and phase grating rotation around an axis parallel to the grid lines. This grating rotation changes the grating shape (i.e. the distributions of phase shifts). This can yield higher visibilities than derived from rectangular shapes.
Our study includes experimental results obtained from synchrotron radiation, as well as simulations for monochromatic radiation. The advantages of Talbot-Lau interferometry are demonstrated at the example of glass capillaries.
T2 - 19th World Conference on Non-Destructive Testing 2016
CY - Munich, Germany
DA - 13.06.2016
KW - Talbot- Lau interferometry
KW - Phase grating
KW - Non-destructive testing
PY - 2016
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-383163
SP - Tu_3_G_2, 1
EP - 9
AN - OPUS4-38316
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Müller, Axel
T1 - Analysis of microplastics in soil samples by using a thermal decomposition method
N2 - While plastics have become indispensable in our daily lives over the last decades, the input into the environment has been increasing concurrently. Plastics often end up in the environment because of intensive use and poor waste management practice. They are subjected to aging and fragmentation and finally be deposited as microplastic particles or in short microplastics (MP). MP are defined as particles originating from synthetic polymers between 1 µm and 5 mm.
Although the pervasive abundance of MP in aquatic environments has been demonstrated comprehensively, less is known about the occurrence and fate of MP in terrestrial ecosystems. It is still unclear if soil functions as a MP source or a sink for aquatic environments. MP can either be transported into water bodies by soil erosion or be retained in soils. The few studies published are not comparable because of non-existent harmonized and standardized methods for sampling, sample preparation, and analysis.
For an assessment of a potential exposure situation of MP, the determination of a mass content in the soil is crucial. Consequently, spectroscopic methods like Raman or FTIR are not suitable, as they deliver information about the shape and size of individual particles. Therefore, we show the application of ThermoExtractionDesorption-GasChromatography-MassSpectrometry (TED-GC-MS) for MP analysis in the soil. In this method, the soil sample is heated up to 600 °C in a nitrogen atmosphere. The decomposition gases are sorbed on a solid phase, then transferred to a GS-MS system where they are desorbed, separated and identified. The method allows the rapid identification of individual polymers through the detection of specific decomposition products, but also the quantitative determination of the MP mass. Besides thermoplastics, elastomers originated from tire abrasion, can be detected.
In the present study, several terrestrial ecosystems in south-west Germany were systematically sampled. Subsequent sample preparation included sieving in fractions of 5-100 µm, 100-1000 µm, and 1-5 mm. MP were extracted by density separation using ZnCl2 solutions. The detection was done by TED-GC-MS measurements. Data of agricultural areas and floodplains are presented exemplarily. A quantitative assessment of highly occurring MP from littering as well as tire abrasion is conducted.
T2 - EGU 2019 - European Geoscience Union General Assembly 2019
CY - Wien, Austria
DA - 07.04.2019
KW - TED-GC-MS
KW - Soil
KW - Microplastics
KW - Analysis
PY - 2019
AN - OPUS4-47822
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Müller, Bernd R.
A1 - Cooper, R.C.
A1 - Lange, Axel
A1 - Kupsch, Andreas
A1 - Wheeler, M.
A1 - Hentschel, Manfred P.
A1 - Staude, Andreas
A1 - Pandey, A.
A1 - Shyam, A.
A1 - Bruno, Giovanni
T1 - Stress-induced microcrack density evolution in β-eucryptite ceramics: Experimental observations and possible route to strain hardening
N2 - In order to investigate their microcracking behaviour, the microstructures of several β-eucryptite ceramics, obtained from glass precursor and cerammed to yield different grain sizes and microcrack densities, were characterized by laboratory and synchrotron x-ray refraction and tomography. Results were compared with those obtained from scanning electron microscopy (SEM). In SEM images, the characterized materials appeared fully dense but computed tomography showed the presence of pore clusters. Uniaxial tensile testing was performed on specimens while strain maps were recorded and analyzed by Digital Image Correlation (DIC). X-ray refraction techniques were applied on specimens before and after tensile testing to measure the amount of the internal specific surface (i.e., area per unit volume). X-ray refraction revealed that (a) the small grain size (SGS) material contained a large specific surface, originating from the grain boundaries and the interfaces of TiO2 precipitates; (b) the medium (MGS) and large grain size (LGS) materials possessed higher amounts of specific surface compared to SGS material due to microcracks, which decreased after tensile loading; (c) the precursor glass had negligible internal surface. The unexpected decrease in the internal surface of MGS and LGS after tensile testing is explained by the presence of compressive regions in the DIC strain maps and further by theoretical arguments. It is suggested that while some microcracks merge via propagation, more close mechanically, thereby explaining the observed X-ray refraction results. The mechanisms proposed would allow the development of a strain hardening route in ceramics.
KW - Beta-eucryptite
KW - Microcracked ceramics
KW - X-ray refraction
KW - Tensile load
KW - Strain hardening
KW - Synchrotron
KW - BAMline
KW - Computed Tomography
KW - CT
PY - 2018
UR - http://www.sciencedirect.com/science/article/pii/S1359645417308881
DO - https://doi.org/10.1016/j.actamat.2017.10.030
SN - 1359-6454
SN - 1873-2453
VL - 144
IS - Supplement C
SP - 627
EP - 641
PB - Elsevier B.V.
AN - OPUS4-43024
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Laquai, René
A1 - Schaupp, Thomas
A1 - Griesche, Axel
A1 - Müller, Bernd R.
A1 - Kupsch, Andreas
A1 - Hannemann, Andreas
A1 - Kannengießer, Thomas
A1 - Bruno, Giovanni
T1 - Quantitative analysis of hydrogen-assisted microcracking in duplex stainless steel through X-ray refraction 3D imaging
N2 - While the problem of the identification of mechanisms of hydrogen assisted damage has and is being thoroughly studied, the quantitative analysis of such damage still lacks suitable tools. In fact, while, for instance, electron microscopy yields excellent characterization, the quantitative analysis of damage requires at the same time large field-of-views and high spatial resolution. Synchrotron X-ray refraction techniques do possess both features. In this work, we show how synchrotron X-ray refraction computed tomography (SXRCT) can quantify damage induced by hydrogen embrittlement in a lean duplex steel, yielding results that overperform even those achievable by synchrotron X-ray absorption computed tomography. As already reported in literature, but this time using a non-destructive technique, we show that the hydrogen charge does not penetrate to the center of tensile specimens. By the comparison between virgin and hydrogen-charged specimens, we deduce that cracks in the specimen bulk are due to the rolling process rather than hydrogen-assisted. We show that (micro)cracks propagate from the surface of tensile specimens to the interior with increasing applied strain, and we deduce that a significant crack propagation can only be observed short before rupture.
KW - 2101 duplex stainless steel
KW - Hydrogen embrittlement
KW - Synchrotron radiation
KW - X-ray refraction
KW - Computed tomography
KW - Microcracking
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-542811
DO - https://doi.org/10.1002/adem.202101287
SN - 1438-1656
SP - 1
EP - 10
PB - Wiley-VCH
CY - Weinheim
AN - OPUS4-54281
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kupsch, Andreas
A1 - Lange, Axel
A1 - Hentschel, Manfred P.
A1 - Onel, Yener
A1 - Wolk, Thomas
A1 - Staude, Andreas
A1 - Ehrig, Karsten
A1 - Müller, Bernd R.
A1 - Bruno, Giovanni
T1 - Evaluating porosity in cordierite diesel particulate filter materials, part 1 X-ray refraction
N2 - Bi-continuous porous ceramics for filtration applications possess a particularly complicated microstructure, with porosity and solid matter being intermingled. Mechanical, thermal, and filtration properties can only be precisely estimated if the morphology of both solid matter and porosity can be quantitatively determined. Using x-ray absorption and refraction, we quantitatively evaluate porosity and pore orientation in cordierite diesel particulate filter ceramics. Porosity values turn out to agree with mercury intrusion measurements, while pore orientation factors agree with published crystallographic texture data.
KW - Porous ceramics
KW - Pore orientation
KW - X-ray refraction
KW - Synchrotron
KW - Interface
PY - 2013
DO - https://doi.org/10.4416/JCST2013-00021
SN - 2190-9385
VL - 4
IS - 4
SP - 169
EP - 176
PB - Göller
CY - Baden-Baden
AN - OPUS4-29939
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Kupsch, Andreas
A1 - Hentschel, Manfred P.
A1 - Lange, Axel
A1 - Bruno, Giovanni
A1 - Müller, Bernd R.
T1 - Direct X-ray refraction of micro structures
N2 - For the first time we present direct 2D imaging of refracted X-rays without any discrimination of the Primary radiation. X-refraction works in analogy to visible light optics: X-rays are entirely deflected at interfaces where discontinuities of (electron) density occur. This is demonstrated at the example of inner and outer surfaces of model samples of well-defined geometry (fibres, capillaries, and monodisperse micro particles). The samples are scanned through a 50 μm monochromatic (20 keV) pencil beam. In order to warrant a sufficient angular resolution a 2D detector (pixel size 7 μm) is placed 3 m downstream of the sample. Scanning the sample in micron steps allows for detecting local changes of interface / surface orientation directly in two dimensions. At the actual angular resolution of about 3 seconds of arc (scattering vector increments Δk = 10-3 nm-1) and 50 μm spatial resolution (scanning) the material’s inner surfaces (with nanometer separation) can be characterized even at sampling rates below 1 second per frame. Moreover, our technique is suited to directly determine particle diameters of up to 250 nm by means of diffraction fringes. Some potential applications to technical submicron structures are discussed.
T2 - ECNDT 2014 - 11th European conference on non-destructive testing
CY - Prague, Czech Republic
DA - 06.10.2014
KW - X-ray refraction
KW - Phase contrast
KW - Edge artefact
KW - Soft matter radiography
KW - Wavelet transformation
KW - Huygens elementary waves
PY - 2014
SN - 978-80-214-5018-9
SP - 1
EP - 9
AN - OPUS4-31970
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Onel, Yener
A1 - Lange, Axel
A1 - Staude, Andreas
A1 - Ehrig, Karsten
A1 - Kupsch, Andreas
A1 - Hentschel, Manfred P.
A1 - Wolk, Thomas
A1 - Müller, Bernd R.
A1 - Bruno, Giovanni
T1 - Evaluating porosity in cordierite Diesel particulate filter materials, Part 2 statistical analysis of computed tomography data
N2 - Complementary to Part 1 of this work, the bi-continuous microstructure of porous synthetic cordierite ceramics for filtration applications was investigated using 3D x-ray computed tomography at different resolutions. Applying both Fast Fourier Transform and a newly developed image analysis algorithm, we quantitatively evaluated porosity and pore orientation. The statistical approach allows extraction of spatially resolved or average values. Porosity values based on x-ray absorption agree with mercury intrusion measurements, while pore orientation factors agree with x-ray refraction data (Part 1 of this work), and with published crystallographic texture data.
KW - Pore orientation
KW - Porous ceramics
KW - Computed tomography
KW - 3D microstructure
PY - 2013
DO - https://doi.org/10.4416/JCST2013-00022
SN - 2190-9385
VL - 05
IS - 01
SP - 13
EP - 22
PB - Göller
CY - Baden-Baden
AN - OPUS4-30379
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Evsevleev, Sergei
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Kupsch, Andreas
T1 - Refraction driven X-ray caustics at curved interfaces
N2 - X-ray refraction related interaction has received rising interest since about two decades in the field of imaging, beam shaping and analysis although being discovered a century ago. Due to refraction at interfaces in inhomogeneous media X-rays undergo natural focusing (or defocusing) of waves, revealing caustics. Such Kind of intensity patterns are well-known for visible light, but have been sparsely discussed for X-rays. The Variation of irradiation density may be predicted in case of known shapes. Analogously to light optics, the intensity distributions cover several orders of magnitude including complete extinction. The partly convergent (and divergent) caustic stripes originate from narrow zones of typical size of some 10−6 of the boundary curvature radius. For the deflection of plane wave synchrotron radiation (energy in the range of some keV to some ten keV) at rods and tubes of several μm diameter, we find good Agreement between experiments and modeling by ray tracing according to Snell’s law without additional diffraction contributions. Apart from Basic Research implications, caustics may influence the performance of irradiation technologies such as sterilization or molecular cross-linking.
KW - X-ray caustics
KW - X-ray refraction
KW - Irradiation
KW - Radiation shielding
KW - Synchrotron Radiation
PY - 2019
UR - http://www.sciencedirect.com/science/article/pii/S0168900218314591
DO - https://doi.org/10.1016/j.nima.2018.10.152
SN - 0168-9002
SN - 1872-9576
VL - 916
SP - 275
EP - 282
PB - Elsevier
AN - OPUS4-46924
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Laquai, René
A1 - Schaupp, Thomas
A1 - Müller, Bernd R.
A1 - Griesche, Axel
A1 - Bruno, Giovanni
A1 - Kannengießer, Thomas
T1 - 3D imaging of hydrogen assisted cracking in metals using refraction enhanced synchrotron CT
N2 - Hydrogen in metals can cause a degradation of the mechanical properties with possible subsequent hydrogen assisted cracking (HAC). Though, the mechanism of HAC is not completely understood yet and thus suitable methods for in situ investigations to characterise the crack formation are needed. X-ray computed tomography (CT) is a well-known tool for analysing these properties. However, the effective resolution of the detector system limits the detection of small defects by CT. Analyser based imaging (ABI) takes advantage of x-ray refraction at interfaces between volumes of different density, i.e. of cracks, pores, inclusions, etc., within the sample to detect defects smaller than the resolution of the detector system. In this study, measurements on an aluminium alloy weld showed that ABI allows us to resolve the 3D structure of cracks undetected by absorption based CT. Prospective investigations will analyse HAC in steels.
T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering
CY - Berlin, Germany
DA - 2015-09-15
KW - Wasserstoffversprödung
KW - Wasserstoffunterstützte Rissbildung
KW - Röntgenrefraktion
KW - CT
KW - Hydrogen embrittlement (HE)
KW - Hydrogen assisted cracking (HAC)
KW - Aluminium alloy
KW - X-ray refraction
KW - Analyser based imaging
KW - Computed tomography (CT)
KW - Synchrotron radiation
PY - 2015
SN - 1435-4934
SP - 1217
EP - 1224
AN - OPUS4-34287
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Shashev, Yury
A1 - Kupsch, Andreas
A1 - Lange, Axel
A1 - Müller, Bernd R.
A1 - Bruno, Giovanni
T1 - Improving the visibility of phase gratings for Talbot-Lau X-ray imaging
N2 - Talbot-Lau interferometry provides X-ray imaging techniques with significant enhancement of the radiographic contrast of weakly absorbing objects. The grating based technique allows separation of absorption, refraction and small angle scattering effects. The different efficiency of rectangular and triangular shaped phase gratings at varying detector distances is investigated. The interference patterns (Talbot carpets) are modeled for parallel monochromatic radiation and measured by synchrotron radiation. In comparison to rectangular shapes of phase gratings much higher visibility is obtained for triangular shapes which yield enhanced contrast of a glass capillary test specimen.
KW - Visibility
KW - Talbot-Lau interferometry
KW - Phase grating
KW - Synchrotron imaging
KW - X-ray reefraction
PY - 2016
DO - https://doi.org/10.3139/120.110948
SN - 0025-5300
VL - 58
IS - 11-12
SP - 970
EP - 974
PB - Carl Hanser Verlag
CY - München
AN - OPUS4-38422
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Laquai, René
A1 - Schaupp, Thomas
A1 - Müller, Bernd R.
A1 - Griesche, Axel
A1 - Bruno, Giovanni
A1 - Kannengießer, Thomas
T1 - 3D imaging of hydrogen assisted cracking using analyser-based imaging
N2 - To better understand the mechanism of hydrogen assisted cracking (HAC), it is important to investigate the 3D structure of the cracks non-destructively. Since, cracks introduced by HAC are usually very small, conventional x-ray imaging methods often lack the required spatial resolution.
However, the detection of those cracks can be enhanced by taking advantage of refraction at interfaces within the sample.
To image this refractive deflection we employ analyser based imaging (ABI). In this work we aim at proving the enhanced crack detection of ABI by investigating an alluminum alloy weld.
T2 - BESSY User Meeting 2015
CY - Berlin, Germany
DA - 09.12.2015
KW - X-ray refraction
KW - Synchrotron
KW - Analyser-based imaging
KW - Hydrogen assisted cracking
KW - Welding
PY - 2015
AN - OPUS4-38278
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Shashev, Yury
A1 - Kupsch, Andreas
A1 - Lange, Axel
A1 - Evsevleev, Sergei
A1 - Müller, Bernd R.
A1 - Osenberg, Markus
A1 - Manke, Ingo
A1 - Hentschel, Manfred P.
A1 - Bruno, Giovanni
T1 - Optimizing the visibility of X-ray phase grating interferometry
N2 - The performance of grating interferometers coming up now for Imaging interfaces within materials depends on the efficiency (visibility) of their main component, namely the phase grating. Therefore, experiments with monochromatic synchrotron radiation and corresponding simulations are carried out. The visibility of a Phase grating is optimized by different photon energies, varying detector to grating distances and continuous rotation of the phase grating about the grid lines. Such kind of rotation changes the projected grating shapes, and thereby the distribution profiles of phase shifts. This yields higher visibilities than derived from ideal rectangular shapes. By continuous grating rotation and variation of the propagation distance, we achieve 2D visibility maps. Such maps provide the visibility for a certain combination of grating orientation and detector position. Optimum visibilities occur at considerably smaller distances than in the standard setup.
KW - Synchrotron, BAMline
KW - Talbot-Lau interferometer
KW - X-ray imaging
KW - X-ray refraction
KW - Grating interferometry
KW - X-ray phase contrast
PY - 2017
DO - https://doi.org/10.3139/120.111097
SN - 0025-5300
VL - 59
IS - 11-12
SP - 974
EP - 980
PB - Hanser Verlag
AN - OPUS4-42955
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kupsch, Andreas
A1 - Lange, Axel
A1 - Hentschel, Manfred P.
A1 - Onel, Yener
A1 - Wolk, Thomas
A1 - Staude, Andreas
A1 - Ehrig, Karsten
A1 - Müller, Bernd R.
A1 - Bruno, Giovanni
T1 - Evaluating porosity in cordierite diesel particulate filter materials: advanced X-ray techniques and new statistical analysis methods
N2 - Bi-continuous porous ceramics for filtration applications possess a particularly complicated microstructure, whereby porosity and solid matter are intermingled. Mechanical, thermal, and filtration properties can only be precisely estimated if the morphology of both solid matter and porosity can be quantitatively determined. Using 3D computed tomography (CT) at different resolutions, and several X-ray refraction-based techniques, we quantitatively evaluated porosity and pore orientation in cordierite diesel particulate filter ceramics.Moreover, applying both Fast Fourier Transform (FFT) and a newly developed image analysis algorithm (directional interface variance analysis, DIVA), we quantitatively evaluated porosity and pore orientation. Both the experimental techniques and the statistical approach allow extraction of spatially resolved or average values.Porosity values from synchrotron computed tomography used turn out to agree with mercury intrusion measurements, while pore orientation factors agree with published crystallographic texture data. This latter point also implies that the study of the pore/matter interface is sufficient to describe the morphological properties of these materials.
KW - Diesel particulate filters
KW - DIVA Algorithm
KW - Pore Orientation
KW - Porous Ceramics
KW - X-Ray Computed Tomography
KW - X-Ray Refraction
PY - 2014
DO - https://doi.org/10.4028/www.scientific.net/AST.91.64
SN - 1662-0356
VL - 91
SP - 64
EP - 69
PB - Techna
CY - Faenza
AN - OPUS4-32069
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kupsch, Andreas
A1 - Müller, Bernd R.
A1 - Lange, Axel
A1 - Bruno, Giovanni
T1 - Microstructure Characterization of Ceramics via 2D and 3D X-Ray Refraction Techniques
N2 - 3D imaging techniques are very fashionable nowadays, and allow enormous progress in understanding ceramic microstructure, its evolution, and its link to mechanical, thermal, and transport properties. In this feature article, we report the use of a powerful, yet not so wide-spread, set of X-ray techniques based on refraction effects. X-ray refraction allows determining internal specific surface (surface per unit volume) in a non-destructive fashion, position and orientation sensitive, and with a nanometric detectability. While the techniques are limited by the X-ray absorption of the material under investigation, we demonstrate showcases of ceramics and composite materials, where understanding of process parameter influence or simply of microstructural parameters could be achieved in a way unrivalled even by high-resolution techniques such as electron microscopy or computed tomography.
KW - X-ray refraction
KW - Porosity
KW - Specific surface
KW - Crack detection
KW - Composites
PY - 2017
DO - https://doi.org/10.1016/j.jeurceramsoc.2016.12.031
SN - 0955-2219
SN - 1873-619X
VL - 37
IS - 5
SP - 1879
EP - 1889
PB - Elsevier
CY - Amsterdam
AN - OPUS4-39094
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Lange, Axel
A1 - Hentschel, Manfred P.
A1 - Kupsch, Andreas
A1 - Müller, Bernd R.
T1 - Correction of diffuse X-ray detector based background
N2 - A novel approach to strongly suppress artifacts in radiography and computed tomography caused by the effect of diffuse background Signals (backlight) of 2D X-ray detectors is suggested. Depending on the detector geometry the mechanism may be different, either based on the optical scattering of the fluorescent screen materials into optical detection devices or Compton or X-ray fluorescence scattering by the detector components. Consequently, these erroneous intensity portions result in locally different violations of Lambert Beers law in single projections (radiographs).
When used as input data for computed tomography these violations are directly observed via modulation of the projected mass as a function of the rotation Phase and the samples aspect ratio (dynamics). The magnitude of the diffuse Background signal depends on the detector area covered by the projected sample. They are more pronounced the smaller the shaded area and the stronger the total attenuation.
Moreover, the local intensity mismatch depends on the attenuation of the sample.
We present very basic reference data measured with multiple metal foils at a synchrotron radiation source. Beam hardening artifacts can be excluded due to the monochromatic radiation. The proposed correction procedure assumes a constant (non-local) scattering mechanism.
T2 - DIR 2011 - International symposium on digital industrial raidology and computed tomography
CY - Berlin, Germany
DA - 20.06.2011
KW - Backlight
KW - X-ray detector
KW - Fluorescence screen
KW - Synchrotron radiography
KW - Computed tomography
PY - 2011
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-243589
SN - 978-3-940283-34-4
IS - DGZfP-BB 128 (Poster 24)
SP - 1
EP - 7
PB - Deutsche Gesellscahft für Zerstörungsfreie Prüfung e.V. (DGZfP)
AN - OPUS4-24358
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Kupsch, Andreas
A1 - Hentschel, Manfred P.
A1 - Lange, Axel
A1 - Müller, Bernd R.
T1 - Röntgen-Interface-Radiographie im Dunkelfeld
N2 - Es wird ein Verfahren zur Röntgenabbildung schwach absorbierender Objekte vorgestellt. Als kontrastgebender Effekt wird die Röntgenrefraktion an Ober- und Grenzflächen ausgenutzt. Zur Erzeugung eines sogenannten Dunkelfeldes wird ein schwach gekrümmter Transmissionskristall eingesetzt, der lokal, d.h. in einem kleinen Ausschnitt des Einstrahlquerschnitts, die Bragg-Bedingung erfüllt. Innerhalb dieser Zone erscheinen die durch Refraktion abgelenkten Strahlkomponenten als hell leuchtende Interface-Strukturen. Die Synthese mehrerer Dunkelfeldstreifen ergibt hochaufgelöste 2D Beispiel von biologischen und technischen Mikrostrukturen.
T2 - DGZfP-Jahrestagung 2013
CY - Dresden, Germany
DA - 06.05.2013
KW - Refraction enhanced imaging (REI)
KW - Radiographie
KW - Dunkelfeldabbildung
KW - Röntgenrefraktion
PY - 2013
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-286900
SN - 978-3-940283-49-8
IS - Di.3.C.1
SP - 1
EP - 7
PB - Deutsche Gesellschaft für zerstörungsfreie Prüfung e.V. (DGZfP)
AN - OPUS4-28690
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Müller, Axel
A1 - Altmann, Korinna
A1 - Kocher, B.
A1 - Braun, U.
T1 - Determination of tire wear markers in soil samples and their distribution in a roadside soil
N2 - Tire wear (TW) constitutes a significant source of microplastic in terrestrial ecosystems. It is known that particles emitted by roads can have an effect up to 100 m into adjacent areas. Here, we apply for the first-time thermal extraction desorption gas chromatography-mass spectrometry (TED-GC/MS) to determine TW in soil samples by detection of thermal decomposition products of styrene-butadiene rubber (SBR), without additional enrichment. Additionally, zinc contents were determined as an elemental marker for TW. Mixed soil samples were taken along three transects along a German motorway in 0.3, 2.0, and 5.0 m distance from the road. Sampling depths were 0–2, 2–5, 5–10, and 10–20 cm. Four fine fractions, 1 000–500, 500–100, 100–50, and <50 μm, were analyzed.
TW contents based on SBR ranged from 155 to 15 898 mg kg−1. TW contents based on zinc were between 413 and 44 812 mg kg−1. Comparison of individual values of SBR and zinc reveals SBR as a more specific marker. Results confirm that most TW ends up in the topsoil within a 2 m distance.
The sampling strategy resulted in representative data for a larger area. Standard deviations of quadruple TED-GC/MS determination of SBR were <10% for all grain size fractions. TED-GC/MS is a suitable analytical tool for determining TW in soil samples without the use of toxic chemicals, enrichment, or special sample preparation.
KW - Microplastic
KW - TED-GC/MS
KW - Tire wear
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543344
DO - https://doi.org/10.1016/j.chemosphere.2022.133653
VL - 294
SP - 1
EP - 8
PB - Elsevier Ltd.
AN - OPUS4-54334
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Müller, Axel
T1 - Representative sampling of roadside soil and determination of tire wear contents by TED-GC/MS
N2 - The presentation describes microplastic findings from tyre wear near roads. Both the sampling and the analysis are presented.
T2 - Mikroplastik Workshop der Hochschule Zittau
CY - Online meeting
DA - 25.11.2021
KW - Mikroplastik
KW - Reifenabrieb
KW - TED-GC/MS
KW - Probennahme
PY - 2021
AN - OPUS4-53831
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rösler, Alexander
A1 - Weidner, Steffen
A1 - Klamroth, Tillmann
A1 - Müller, Axel HE
A1 - Schlaad, Helmut
T1 - Kinetics of anionic polymerization of β‐myrcene in hydrocarbon solvents
N2 - AbstractThe kinetics of anionic polymerization of β‐myrcene initiated by sec‐butyllithium were examined in saturated and unsaturated hydrocarbon solvents, i.e. cyclohexane, cyclohexene, 4‐vinylcyclohexene and dl‐limonene. Polymerizations usually proceeded in a living manner, i.e. in the absence of termination and chain transfer reactions, in all solvents, to produce well‐defined polymyrcenes with high content (85%) of cis‐1,4 units. However, polymyrcenyllithium chains exhibited limited long‐term stability in 4‐vinylcyclohexene solution, most probably due to chain transfer to solvent. Reaction orders with respect to the concentration of active chains were found to be one‐quarter in cyclohexane increasing to one‐half in unsaturated solvents, indicating that the polymyrcenyllithium chains are present as tetrameric or dimeric associates, respectively. Apparent activation energies were found to be 81 kJ mol−1 in cyclohexane and 77 kJ mol−1 in dl‐limonene solution, which are close to the values obtained by quantum chemical calculations. © 2025 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
KW - Myrcene
KW - Anionic polymerization
KW - MALDI TOF MS
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-649039
DO - https://doi.org/10.1002/pi.6772
SN - 0959-8103
SP - 1
EP - 8
PB - Wiley
AN - OPUS4-64903
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Lange, Axel
A1 - Kupsch, Andreas
A1 - Hentschel, Manfred P.
A1 - Müller, Bernd R.
T1 - Straightforward correction of X-ray detector backlighting
N2 - A novel approach to strongly suppress artifacts in radiography and computed tomography caused by the effect of diffuse background signals ('backlighting') of 2D X-ray detectors is suggested. Depending on the detector geometry the mechanism may be different, either based on the optical scattering of the fluorescent screen materials into optical detection devices or Compton or X-ray fluorescence scattering by the detector components. Consequently, these erroneous intensity portions result in locally different violations of Lambert Beers law in single projections (radiographs) as function of the detector area coverage and the magnitude of the attenuation.
The absorption of multiple metal sheets is investigated by monochromatic synchrotron radiation, thus excluding beam hardening. The proposed correction procedure simply requires the individual subtraction of one and the same fraction of the primary and transmitted mean intensity, as a constant (non-local) scattering mechanism is assumed.
T2 - 18th WCNDT - World conference on nondestructive testing
CY - Durban, South Africa
DA - 16.04.2012
KW - X-ray detector backlighting
KW - Radiography
KW - Fluorescent screen
KW - Diffuse background
KW - Computed tomography
PY - 2012
UR - http://www.ndt.net/article/wcndt2012/papers/205_wcndtfinal00205.pdf
SN - 978-0-620-52872-6
SP - 1
EP - 8(?)
AN - OPUS4-25835
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Lange, Axel
A1 - Kupsch, Andreas
A1 - Müller, Bernd R.
A1 - Hentschel, Manfred P.
T1 - Edge artefacts of radiographic images by X-ray refraction
N2 - The relevance of nano sized structures and interfaces in upcoming technologies requires new non-destructive Xray techniques exploiting attenuation as well as scattering. In the course of driving the resolution and the contrast of modern radiography into micro and nano metre dimension the inevitable scattering effects require increased attention. Several radiologists interpret the observed edge artefacts simply by 'phase contrast' due to different X-ray path lengths within the sample and others refer to Fresnel scattering. The ultra small angle scattering is of high intensity and may reach the level of the primary beam. We present monochromatic synchrotron measurements on rather simply shaped objects (such as plates and cylinders) which prove clearly the dominance of refraction intensity over total reflection and coherent small angle scattering. The refraction conditions hold for angles of incidence of several degrees to the surface, but typical deflection angles range from several seconds to minutes of arc. Additionally to the concept of 'phase contrast' of the primary beam its deflection becomes the essential issue. The appropriate removal of the attenuation contribution enables the imaging of inner surfaces and interfaces by refraction scanning topography. The presented measurements of reference particles demonstrate the reliability of laboratory refraction scanners applying X-ray tubes.
T2 - 18th WCNDT - World conference on nondestructive testing
CY - Durban, South Africa
DA - 16.04.2012
KW - X-ray refraction
KW - Small angle scattering
KW - Phase contrast radiography
KW - Refraction topography
KW - Nanostructures
KW - Nanocracks
PY - 2012
UR - http://www.ndt.net/article/wcndt2012/papers/274_wcndtfinal00274.pdf
SN - 978-0-620-52872-6
SP - 1
EP - 11
AN - OPUS4-25836
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Lange, Axel
A1 - Hentschel, Manfred P.
A1 - Kupsch, Andreas
A1 - Müller, Bernd R.
T1 - Numerical correction of X-ray detector backlighting
N2 - A novel approach to strongly suppress artifacts in radiography and computed tomography caused by the effect of diffuse background signals ('backlighting') of 2D X-ray detectors is suggested. Depending on the detector geometry the mechanism may be different, either based on the optical scattering by the fluorescent screen materials into optical detection devices or Compton or X-ray fluorescence scattering by the detector components. Consequently, these erroneous intensity portions result in locally different violations of Lambert–Beer's law in single projections (radiographs). When used as input data for computed tomography these violations are directly observed via modulation of the projected mass as a function of the rotation phase and the samples aspect ratio (dynamics). The magnitude of the diffuse background signal depends on the detector area covered by the projected sample. They are more pronounced the smaller the shadowed area and the stronger the total attenuation. This implies that the reconstruction suffers from additional anisotropic artifacts caused by elongated sample structures. This issue is studied simply by absorption of flat plates in a conventional laboratory radiography set-up and at a synchrotron radiation facility. In the latter case beam hardening artifacts can be excluded due to the monochromatic radiation. The proposed correction procedure requires simple integral intensity offsets as a constant (non-local) light scattering mechanism is assumed.
KW - Detector backlighting
KW - X-ray detector scattering
KW - Fluorescent screen
KW - Diffuse background
KW - Computed tomography
PY - 2012
DO - https://doi.org/10.3139/146.110659
SN - 1862-5282
VL - 103
IS - 2
SP - 174
EP - 178
PB - Carl Hanser
CY - München
AN - OPUS4-25553
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rösler, Alexander
A1 - Weidner, Steffen
A1 - Klamroth, Tillmann
A1 - Müller, Axel H. E.
A1 - Schlaad, Helmut
T1 - Kinetics of anionic polymerization of β‐myrcene in hydrocarbon solvents
N2 - The kinetics of anionic polymerization of β‐myrcene initiated by sec‐butyllithium were examined in saturated and unsaturated hydrocarbon solvents, i.e. cyclohexane, cyclohexene, 4‐vinylcyclohexene and dl‐limonene. Polymerizations usually proceeded in a living manner, i.e. in the absence of termination and chain transfer reactions, in all solvents, to produce well‐defined polymyrcenes with high content (85%) of cis‐1,4 units. However, polymyrcenyllithium chains exhibited limited long‐term stability in 4‐vinylcyclohexene solution, most probably due to chain transfer to solvent. Reaction orders with respect to the concentration of active chains were found to be one‐quarter in cyclohexane increasing to one‐half in unsaturated solvents, indicating that the polymyrcenyllithium chains are present as tetrameric or dimeric associates, respectively. Apparent activation energies were found to be 81 kJ mol−1 in cyclohexane and 77 kJ mol−1 in dl‐limonene solution, which are close to the values obtained by quantum chemical calculations.
KW - MALDI-TOF MS
KW - Anionic polymerization
KW - β‐myrcene
KW - Kinetics
KW - Reaction order
KW - Activation energy
KW - Microstructure
KW - Quantum chemical calculations
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630900
DO - https://doi.org/10.1002/pi.6772
SN - 1097-0126
SP - 1
EP - 8
PB - Wiley
CY - New York, NY
AN - OPUS4-63090
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rösler, Alexander
A1 - Weidner, Steffen
A1 - Klamroth, Tillmann
A1 - Müller, Axel HE
A1 - Schlaad, Helmut
T1 - Kinetics of anionic polymerization of β‐myrcene in hydrocarbon solvents
N2 - AbstractThe kinetics of anionic polymerization of β‐myrcene initiated by sec‐butyllithium were examined in saturated and unsaturated hydrocarbon solvents, i.e. cyclohexane, cyclohexene, 4‐vinylcyclohexene and dl‐limonene. Polymerizations usually proceeded in a living manner, i.e. in the absence of termination and chain transfer reactions, in all solvents, to produce well‐defined polymyrcenes with high content (85%) of cis‐1,4 units. However, polymyrcenyllithium chains exhibited limited long‐term stability in 4‐vinylcyclohexene solution, most probably due to chain transfer to solvent. Reaction orders with respect to the concentration of active chains were found to be one‐quarter in cyclohexane increasing to one‐half in unsaturated solvents, indicating that the polymyrcenyllithium chains are present as tetrameric or dimeric associates, respectively. Apparent activation energies were found to be 81 kJ mol−1 in cyclohexane and 77 kJ mol−1 in dl‐limonene solution, which are close to the values obtained by quantum chemical calculations. © 2025 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
KW - Myrcene
KW - Anionic polymerization
KW - Reaction order
KW - Activation energy
KW - Microstructure
KW - Quantum chemical calculation
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-636840
DO - https://doi.org/10.1002/pi.6772
SN - 0959-8103
SP - 1
EP - 8
PB - Wiley
AN - OPUS4-63684
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -