O. Bunk

Details der Publikationsliste

Zeitraum

1999 - 2010

Anzahl

66

Co-Autoren

X-ray reflectivity reveals equilibrium density profile of molecular liquid under nanometre confinement (2010)

Perret, E., Nygård, K., Satapathy, Dillip Kumar, Balmer, T. E., Bunk, O., Heuberger, M., ...

A silane (tetrakis(trimethylsiloxy)silane) has been confined within a space of a few molecular diameters (9 Å) between two atomically flat opposing mica membranes. The liquid's electron density...

X-ray reflectivity reveals equilibrium density profile of molecular liquid under nanometre confinement (2010)

Perret, E., Nygård, K., Satapathy, Dillip Kumar, Balmer, T. E., Bunk, O., Heuberger, M., ...

A silane (tetrakis(trimethylsiloxy)silane) has been confined within a space of a few molecular diameters (9 Å) between two atomically flat opposing mica membranes. The liquid's electron density...

Quantitative phase-contrast tomography of a liquid phantom using a conventional x-ray tube source (2009)

Herzen, J., Donath, T., Pfeiffer, F., Bunk, O., Padeste, C., Beckmann, F., ...

Over the last few years, differential phase-contrast x-ray computed tomography (PC-CT) using a hard x-ray grating interferometer and polychromatic x-ray tube sources has been developed. The method...

X-Ray Coherent Diffraction Microscopy of Extended Objects (2008)

F. Pfeiffer, M. Dierolf, O. Bunk, I. Johnson, P. Thibault, A. Menzel, ...

We report on the recent development of a lensless coherent diffraction microscopy scheme, which is based on the combination of ptychography with an iterative phase retrieval algorithm [1]. The method...

Neutron Decoherence Imaging for Visualizing Bulk Magnetic Domain Structures (2008)

Grünzweig, C., David, C., Bunk, O., Dierolf, M., Frei, G., Kühne, G., ...

Here we introduce a novel neutron imaging method, which is based on the effect that the spatial coherence of the neutron wave front can be changed through small-angle scattering of neutrons at...

Colloidal monolayer trapped near a charged wall: A synchrotron x-ray diffraction study (2008)

Satapathy, D.K., Bunk, O., Jefimovs, K., Nygård, K., Guo, H., Diaz, A., ...

Using x-ray diffraction from microfluidic channel arrays, we have determined concentration profiles of charge-stabilized silica colloids (radius 60±2 nm) confined between two like-charged dielectric...

Confinement-induced liquid ordering investigated by x-ray phase retrieval (2007)

Bunk, O., Diaz, A., Pfeiffer, F., David, C., Padeste, C., Keymeulen, H., ...

Using synchrotron x-ray diffraction, we have determined the ensemble-averaged density profile of colloidal fluids within confining channels of different widths. We observe an oscillatory...

Diffractive imaging for periodic samples: retrieving one-dimensional concentration profiles across microfluidic channels (2007)

Bunk, O., Diaz, A., Pfeiffer, F., David, C., Schmitt, B., Satapathy, D. K., ...

A technique has been developed that allows determination of the concentration profiles of colloidal solutions or any kind of fluid under confinement. Currently, submicrometre-wide channels are...

Fabrication of diffraction gratings for hard X-ray phase contrast imaging (2007)

David, C., Bruder, J., Rohbeck, T., Grunzweig, C., Kottler, C., Diaz, A., ...

We have developed a method for X-ray phase contrast imaging, which is based on a grating interferometer. The technique is capable of recording the phase shift of hard X-rays travelling through a...

Fabrication of Fresnel zone plates for hard X-rays (2007)

Jefimovs, K., Bunk, O., Pfeiffer, F., Grolimund, D., Van Der Veen, J. F., David, C.

A method to fabricate gold structures with high aspect ratio is presented. Fresnel zone plates with an outermost zone width of 100nm and structures of 1μm height are fabricated. Preliminary focusing...

Grating interferometer based scanning setup for hard x-ray phase contrast imaging (2007)

Kottler, C., Pfeiffer, F., Bunk, O., Grunzweig, C., David, C.

In x-ray radiography, particularly for technical and industrial applications, a scanning setup is very often favorable when compared to a direct two-dimensional image acquisition. Here, we report on...

Hard X-ray phase imaging and tomography using a grating interferometer (2007)

David, C., Weitkamp, T., Pfeiffer, F., Diaz, A., Bruder, J., Rohbeck, T., ...

An interferometric technique for hard X-rays is presented. It is based on two transmission gratings and a phase-stepping technique, and it provides separate radiographs of the phase and absorption...

Hard X-ray phase tomography with low-brilliance sources (2007)

Pfeiffer, F., Kottler, C., Bunk, O., David, C.

We report on a method for tomographic phase contrast imaging of centimeter sized objects. As opposed to existing techniques, our approach can be used with low-brilliance, lab based x-ray sources and...

Hard-x-ray lensless imaging of extended objects (2007)

Rodenburg, J. M., Hurst, A. C., Cullis, A. G., Dobson, B. R., Pfeiffer, F., Bunk, O., ...

We demonstrate a hard-x-ray microscope that does not use a lens and is not limited to a small field of view or an object of finite size. The method does not suffer any of the physical constraints,...

High-resolution differential phase contrast imaging using a magnifying projection geometry with a microfocus x-ray source (2007)

Engelhardt, M., Baumann, J., Schuster, M., Kottler, C., Pfeiffer, F., Bunk, O., ...

Differential x-ray phase contrast imaging using a grating interferometer was combined with a magnifying cone beam geometry using a conventional microfocus x-ray tube. This brings the advantages of a...

Phase contrast X-ray imaging of large samples using an incoherent laboratory source (2007)

Kottler, C., Pfeiffer, F., Bunk, O., Grünzweig, C., Bruder, J., Kaufmann, R., ...

An interferometric method to record quantitative X-ray phase contrast images has been developed that can be used at polychromatic and incoherent X-ray sources such as laboratory tubes. With respect...

Tomographic reconstruction of three-dimensional objects from hard X-ray differential phase contrast projection images (2007)

Pfeiffer, F., Bunk, O., Kottler, C., David, C.

We report on a method for tomographic phase contrast imaging of centimeter sized objects. As opposed to existing techniques, our approach can be used with low-brilliance, lab based X-ray sources and...

A two-directional approach for grating based differential phase contrast imaging using hard x-rays (2007)

Kottler, C., David, C., Pfeiffer, F., Bunk, O.

We report on a two-directional approach for grating based x-ray differential phase contrast imaging. In order to retrieve good quality and artifact-free phase images for quantitative analysis and...

Phase contrast X-ray imaging of large samples using an incoherent laboratory source. (2007)

Kottler, C., Pfeiffer, F., Bunk, O., Grünzweig, C., Bruder, J., Kaufmann, R., ...

8th Biennial Conference on High Resolution X-ray Diffraction and Imaging (XTOP 2006), Baden-Baden, September 19-22, 2006

Quantitative phase imaging and tomography with polychromatic X-rays. (2007)

David, C., Weitkamp, T., Khan, T., Pfeiffer, F., Bunk, O., Diaz, A., ...

Proc.of the 8th Internat.Conf.on X-Ray Microscopy, Himeji, J, July 16-30, 2005

Phase retrieval and differential phase-contrast imaging with low-brilliance X-ray sources (2006)

Pfeiffer, F., Weitkamp, T., Bunk, O., David, C.

X-ray radiographic absorption imaging is an invaluable tool in medical diagnostics and materials science. For biological tissue samples, polymers or fibre composites, however, the use of conventional...

Phase retrieval and differential phase contrast imaging with hard X-rays and cold neutrons. (2006)

David, C., Pfeiffer, F., Kottler, C., Grünzweig, C., Bunk, O., Stampanoni, M., ...

8th Bienneal Conf.on High Resolution X-Ray Diffraction and Imaging (XTOP 2006), Baden-Baden, September 19-22, 2006

Coherence requirements in hard X-ray grating interferometry. (2006)

Weitkamp, T., Kottler, C., Bunk, O., Pfeiffer, F., David, C.

8th Bienneal Conf.on High Resolution X-Ray Diffraction and Imaging (XTOP 2006), Baden-Baden, September 19-22, 2006

Shearing interferometer for quantifying the coherence of hard X-ray beams (2005)

Pfeiffer, F., Bunk, O., Schulze-Briese, C., Diaz, A., Weitkamp, T., David, C., ...

We report a quantitative measurement of the full transverse coherence function of the 14.4 keV x-ray radiation produced by an undulator at the Swiss Light Source. An x-ray grating interferometer...

Shearing interferometer for quantifying the coherence of hard x-ray beams (2005)

Pfeiffer, F., Bunk, O., Schulze-Briese, C., Diaz, A., Weitkamp, T., David, C., ...

We report a quantitative measurement of the full transverse coherence function of the 14.4 keV x-ray radiation produced by an undulator at the Swiss Light Source. An x-ray grating interferometer...

X-ray beam-position monitoring in the sub-micrometre and sub-second regime (2005)

Bunk, O., Pfeiffer, F., Stampanoni, M., Patterson, B. D., Schulze-Briese, C., David, C.

It is demonstrated that X-ray beam positions can be extracted from two-dimensional profiles with sub-pixel resolution. Beam-position measurements utilizing a self-designed low-cost two-dimensional...

Ge(001)-(2 1 0 3)-Pb (2 1 0 6)-Pb: low-temperature two-dimensional phase transition (2001)

Bunk, O., Nielsen, M. M., Zeysing, J. H., Falkenberg, G., Berg-Rasmussen, F., Nielsen, M., ...

The Ge(001)-(2 1 0 3)-Pb surface reconstruction with a lead coverage of 5/3 monolayer is on the borderline between the low-coverage covalently-bonded and high-coverage metallic lead overlayers. This...

Phase transitions in two dimensions - the case of Sn adsorbed on Ge(111) surfaces (1999)

Bunk, O., Zeysing, J. H., Falkenberg, G., Johnson, R. L., Nielsen, M., Nielsen, M. M., ...

Accurate atomic coordinates of the room-temperature (root3xroot3)R30degree and low-temperature (3x3) phases of 1/3 ML Sn on Ge(111) have been established by grazing-incidence x-ray diffraction with...

Structure determination of the indium-induced Si(111)-(4x1) reconstruction by surface x-ray diffraction (1999)

Bunk, O., Falkenberg, G., Zeysing, J. H., Lottermoser, L., Johnson, R. L., Nielsen, M., ...

A detailed structural model for the indium-induced Si(111)-(4x1) surface reconstruction has been determined by analyzing an extensive set of x-ray-diffraction data recorded with monochromatic...