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Papers by Anatoly Shabalin

Research paper thumbnail of Hanbury Brown–Twiss Interferometry at a Free-Electron Laser

Physical Review Letters, 2013

We present measurements of second-and higher-order intensity correlation functions (so-called Han... more We present measurements of second-and higher-order intensity correlation functions (so-called Hanbury Brown and Twiss experiment) performed at the freeelectron laser (FEL) FLASH in the non-linear regime of its operation. We demonstrate the high transverse coherence properties of the FEL beam with a degree of transverse coherence of about 80% and degeneracy parameter of the order 10 9 that makes it similar to laser sources. Intensity correlation measurements in spatial and frequency domain gave an estimate of the FEL average pulse duration of 50 fs. Our measurements of the higher-order correlation functions indicate that FEL radiation obeys Gaussian statistics, which is characteristic to chaotic sources. PACS numbers: 41.60.Cr,42.25.Kb,42.50.Ar,42.55.Vc Hanbury Brown and Twiss in their pioneering experiments demonstrated that one can get fundamental information on the statistics of light sources by measuring intensity correlations at two separated spatial positions. Originally designed as a robust method to * present address:

Research paper thumbnail of Double hexagonal close-packed structure revealed in a single colloidal crystal grain by Bragg rod analysis

Journal of Applied Crystallography, 2014

Author(s) of this paper may load this reprint on their own web site or institutional repository p... more Author(s) of this paper may load this reprint on their own web site or institutional repository provided that this cover page is retained. Republication of this article or its storage in electronic databases other than as specified above is not permitted without prior permission in writing from the IUCr.

Research paper thumbnail of Characterization of spatial coherence of synchrotron radiation with non-redundant arrays of apertures

Journal of Synchrotron Radiation, 2014

We present a method to characterize the spatial coherence of soft X-ray radiation from a single d... more We present a method to characterize the spatial coherence of soft X-ray radiation from a single diffraction pattern. The technique is based on scattering from non-redundant arrays (NRA) of slits and records the degree of spatial coherence at several relative separations from one to 15 microns, simultaneously. Using NRAs we measured the transverse coherence of the X-ray beam at the XUV X-ray beamline P04 of the PETRA III synchrotron storage ring as a function of different beam parameters. To verify the results obtained with the NRAs additional Young's double pinhole experiments were conducted and show good agreement.

Research paper thumbnail of Spatially resolved x-ray studies of liquid crystals with strongly developed bond-orientational order

Physical Review E, 2015

We present an x-ray study of freely suspended hexatic films of the liquid crystal 3(10)OBC.

Research paper thumbnail of In situ X-ray crystallography of colloidal crystals under sintering conditions

Acta Crystallographica Section A Foundations and Advances, 2015

Research paper thumbnail of Ptychographic Imaging of Fossil Diatom Structures with Soft X-Rays

Research paper thumbnail of Theoretical analysis of the strain mapping in a single core-shell nanowire by x-ray Bragg ptychography

X-Ray Nanoimaging: Instruments and Methods II, 2015

Research paper thumbnail of Nanofocused x-ray beams applied for mapping strain in core-shell nanowires

X-Ray Nanoimaging: Instruments and Methods II, 2015

Research paper thumbnail of Strain mapping in an InGaN/GaN nanowire using a nano-focused x-ray beam

Applied Physics Letters, 2015

Research paper thumbnail of Water window ptychographic imaging with characterized coherent X-rays

Journal of Synchrotron Radiation, 2015

We report on a ptychographical coherent diffractive imaging experiment in the water window with f... more We report on a ptychographical coherent diffractive imaging experiment in the water window with focused soft X-rays at 500 eV. An X-ray beam with high degree of coherence was selected for ptychography at the P04 beamline of the PETRA III synchrotron radiation source. We measured the beam coherence with the newly developed

Research paper thumbnail of Double hexagonal close-packed structure revealed in a single colloidal crystal grain by Bragg rod analysis

Journal of Applied Crystallography, 2014

Author(s) of this paper may load this reprint on their own web site or institutional repository p... more Author(s) of this paper may load this reprint on their own web site or institutional repository provided that this cover page is retained. Republication of this article or its storage in electronic databases other than as specified above is not permitted without prior permission in writing from the IUCr.

Research paper thumbnail of X-ray cross-correlation analysis of liquid crystal membranes in the vicinity of the hexatic-smectic phase transition

Physical Review E, 2013

We present an x-ray study of liquid crystal membranes in the vicinity of hexatic-smectic phase tr... more We present an x-ray study of liquid crystal membranes in the vicinity of hexatic-smectic phase transition by means of angular x-ray cross-correlation analysis (XCCA). By applying two-point angular intensity cross-correlation functions to the measured series of diffraction patterns the parameters of bond-orientational (BO) order in hexatic phase were directly determined. The temperature dependence of the positional correlation lengths was analyzed as well. The obtained correlation lengths show larger values for the higher-order Fourier components of BO order. These findings indicate a strong coupling between BO and positional order that has not been studied in detail up to now.

Research paper thumbnail of Wavefront preserving channel-cut optics for coherent x-ray scattering experiments at the P10 beamline at PETRAIII

Journal of Physics: Conference Series, 2014

ABSTRACT We report on the performance of cryogenically cooled monolithic Si(111) channel-cut mono... more ABSTRACT We report on the performance of cryogenically cooled monolithic Si(111) channel-cut monochromator optics installed at the coherence beamline P10 of the PETRA III synchrotron source. Our results show that a high quality channel-cut monochromator crystal preserves the beam wavefront and provides excellent beam stability, which offers considerable benefits for coherent x-ray scattering experiments.

Research paper thumbnail of In situ X-ray crystallographic study of the structural evolution of colloidal crystals upon heating

Journal of Applied Crystallography, 2013

This open-access article is distributed under the terms of the Creative Commons Attribution Licen... more This open-access article is distributed under the terms of the Creative Commons Attribution Licence http://creativecommons.org/licenses/by/2.0/uk/legalcode, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Research paper thumbnail of Structural Evolution of Colloidal Crystal Films in the Process of Melting Revealed by Bragg Peak Analysis

Langmuir, 2015

In situ X-ray diffraction studies of structural evolution of colloidal crystal films formed by po... more In situ X-ray diffraction studies of structural evolution of colloidal crystal films formed by polystyrene spherical particles upon incremental heating are reported. The Bragg peak parameters, such as peak position, integrated intensity, and radial and azimuthal widths were analyzed as a function of temperature. A quantitative study of colloidal crystal lattice distortions and mosaic spread as a function of temperature was carried out using Williamson−Hall plots based on mosaic block model. The temperature dependence of the diameter of polystyrene particles was obtained from the analysis of Bragg peaks, and the form factor contribution extracted from the diffraction patterns. Four stages of structural evolution in a colloidal crystal upon heating were identified. Based on this analysis, a model of the heating and melting process in the colloidal crystal film is suggested. (A.V.Z.). Figure 9. Schematic diagram of the structural evolution in a colloidal crystal film under incremental heating at nanoscopic (top row) and mesoscopic (bottom row) length scales.

Research paper thumbnail of Hanbury Brown–Twiss Interferometry at a Free-Electron Laser

Physical Review Letters, 2013

We present measurements of second-and higher-order intensity correlation functions (so-called Han... more We present measurements of second-and higher-order intensity correlation functions (so-called Hanbury Brown and Twiss experiment) performed at the freeelectron laser (FEL) FLASH in the non-linear regime of its operation. We demonstrate the high transverse coherence properties of the FEL beam with a degree of transverse coherence of about 80% and degeneracy parameter of the order 10 9 that makes it similar to laser sources. Intensity correlation measurements in spatial and frequency domain gave an estimate of the FEL average pulse duration of 50 fs. Our measurements of the higher-order correlation functions indicate that FEL radiation obeys Gaussian statistics, which is characteristic to chaotic sources. PACS numbers: 41.60.Cr,42.25.Kb,42.50.Ar,42.55.Vc Hanbury Brown and Twiss in their pioneering experiments demonstrated that one can get fundamental information on the statistics of light sources by measuring intensity correlations at two separated spatial positions. Originally designed as a robust method to * present address:

Research paper thumbnail of Double hexagonal close-packed structure revealed in a single colloidal crystal grain by Bragg rod analysis

Journal of Applied Crystallography, 2014

Author(s) of this paper may load this reprint on their own web site or institutional repository p... more Author(s) of this paper may load this reprint on their own web site or institutional repository provided that this cover page is retained. Republication of this article or its storage in electronic databases other than as specified above is not permitted without prior permission in writing from the IUCr.

Research paper thumbnail of Characterization of spatial coherence of synchrotron radiation with non-redundant arrays of apertures

Journal of Synchrotron Radiation, 2014

We present a method to characterize the spatial coherence of soft X-ray radiation from a single d... more We present a method to characterize the spatial coherence of soft X-ray radiation from a single diffraction pattern. The technique is based on scattering from non-redundant arrays (NRA) of slits and records the degree of spatial coherence at several relative separations from one to 15 microns, simultaneously. Using NRAs we measured the transverse coherence of the X-ray beam at the XUV X-ray beamline P04 of the PETRA III synchrotron storage ring as a function of different beam parameters. To verify the results obtained with the NRAs additional Young's double pinhole experiments were conducted and show good agreement.

Research paper thumbnail of Spatially resolved x-ray studies of liquid crystals with strongly developed bond-orientational order

Physical Review E, 2015

We present an x-ray study of freely suspended hexatic films of the liquid crystal 3(10)OBC.

Research paper thumbnail of In situ X-ray crystallography of colloidal crystals under sintering conditions

Acta Crystallographica Section A Foundations and Advances, 2015

Research paper thumbnail of Ptychographic Imaging of Fossil Diatom Structures with Soft X-Rays

Research paper thumbnail of Theoretical analysis of the strain mapping in a single core-shell nanowire by x-ray Bragg ptychography

X-Ray Nanoimaging: Instruments and Methods II, 2015

Research paper thumbnail of Nanofocused x-ray beams applied for mapping strain in core-shell nanowires

X-Ray Nanoimaging: Instruments and Methods II, 2015

Research paper thumbnail of Strain mapping in an InGaN/GaN nanowire using a nano-focused x-ray beam

Applied Physics Letters, 2015

Research paper thumbnail of Water window ptychographic imaging with characterized coherent X-rays

Journal of Synchrotron Radiation, 2015

We report on a ptychographical coherent diffractive imaging experiment in the water window with f... more We report on a ptychographical coherent diffractive imaging experiment in the water window with focused soft X-rays at 500 eV. An X-ray beam with high degree of coherence was selected for ptychography at the P04 beamline of the PETRA III synchrotron radiation source. We measured the beam coherence with the newly developed

Research paper thumbnail of Double hexagonal close-packed structure revealed in a single colloidal crystal grain by Bragg rod analysis

Journal of Applied Crystallography, 2014

Author(s) of this paper may load this reprint on their own web site or institutional repository p... more Author(s) of this paper may load this reprint on their own web site or institutional repository provided that this cover page is retained. Republication of this article or its storage in electronic databases other than as specified above is not permitted without prior permission in writing from the IUCr.

Research paper thumbnail of X-ray cross-correlation analysis of liquid crystal membranes in the vicinity of the hexatic-smectic phase transition

Physical Review E, 2013

We present an x-ray study of liquid crystal membranes in the vicinity of hexatic-smectic phase tr... more We present an x-ray study of liquid crystal membranes in the vicinity of hexatic-smectic phase transition by means of angular x-ray cross-correlation analysis (XCCA). By applying two-point angular intensity cross-correlation functions to the measured series of diffraction patterns the parameters of bond-orientational (BO) order in hexatic phase were directly determined. The temperature dependence of the positional correlation lengths was analyzed as well. The obtained correlation lengths show larger values for the higher-order Fourier components of BO order. These findings indicate a strong coupling between BO and positional order that has not been studied in detail up to now.

Research paper thumbnail of Wavefront preserving channel-cut optics for coherent x-ray scattering experiments at the P10 beamline at PETRAIII

Journal of Physics: Conference Series, 2014

ABSTRACT We report on the performance of cryogenically cooled monolithic Si(111) channel-cut mono... more ABSTRACT We report on the performance of cryogenically cooled monolithic Si(111) channel-cut monochromator optics installed at the coherence beamline P10 of the PETRA III synchrotron source. Our results show that a high quality channel-cut monochromator crystal preserves the beam wavefront and provides excellent beam stability, which offers considerable benefits for coherent x-ray scattering experiments.

Research paper thumbnail of In situ X-ray crystallographic study of the structural evolution of colloidal crystals upon heating

Journal of Applied Crystallography, 2013

This open-access article is distributed under the terms of the Creative Commons Attribution Licen... more This open-access article is distributed under the terms of the Creative Commons Attribution Licence http://creativecommons.org/licenses/by/2.0/uk/legalcode, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Research paper thumbnail of Structural Evolution of Colloidal Crystal Films in the Process of Melting Revealed by Bragg Peak Analysis

Langmuir, 2015

In situ X-ray diffraction studies of structural evolution of colloidal crystal films formed by po... more In situ X-ray diffraction studies of structural evolution of colloidal crystal films formed by polystyrene spherical particles upon incremental heating are reported. The Bragg peak parameters, such as peak position, integrated intensity, and radial and azimuthal widths were analyzed as a function of temperature. A quantitative study of colloidal crystal lattice distortions and mosaic spread as a function of temperature was carried out using Williamson−Hall plots based on mosaic block model. The temperature dependence of the diameter of polystyrene particles was obtained from the analysis of Bragg peaks, and the form factor contribution extracted from the diffraction patterns. Four stages of structural evolution in a colloidal crystal upon heating were identified. Based on this analysis, a model of the heating and melting process in the colloidal crystal film is suggested. (A.V.Z.). Figure 9. Schematic diagram of the structural evolution in a colloidal crystal film under incremental heating at nanoscopic (top row) and mesoscopic (bottom row) length scales.