Johannes Hagemann
University of Göttingen
37 Papers
84 Citations
Johannes Hagemann is an academic researcher from University of Göttingen. The author has contributed to research in topics: Holography & Phase-contrast imaging. The author has an hindex of 8, co-authored 29 publications.
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Papers
A phase-retrieval toolbox for X-ray holography and tomography.
Leon M. Lohse,Anna Lena Robisch,Mareike Töpperwien,Simon Maretzke,Martin Krenkel,Johannes Hagemann,Tim Salditt +6 more
TL;DR: The package is called HoloTomoToolbox and comprises a set of algorithms for phase retrieval in the direct-contrast regime, as well as in the holographic regime, which is used for high-resolution cone-beam synchrotron recordings.
Single-pulse phase-contrast imaging at free-electron lasers in the hard X-ray regime
Johannes Hagemann,M. Vassholz,Hannes Paul Hoeppe,Markus Osterhoff,Juan Manuel Rosselló,Robert Mettin,Frank Seiboth,Andreas Schropp,Johannes Möller,Jörg Hallmann,Chan Kim,Markus Scholz,Ulrike Boesenberg,Robert Schaffer,Alexey Zozulya,Wei Lu,Roman Shayduk,Anders Madsen,Christian G. Schroer,Tim Salditt +19 more
TL;DR: In this article, a concept is presented to address the fluctuating illumination wavefronts by sampling the configuration space of SASE pulses before an actual recording, followed by a principal component analysis.
Probe reconstruction for holographic X-ray imaging.
TL;DR: A comparison of different schemes for probe characterization of an X-ray nano-probe in a near-field imaging setting is presented.
Four-Fold Multi-Modal X-ray Microscopy Measurements of a Cu(In,Ga)Se2 Solar Cell.
Christina Ossig,Christian Strelow,Jan Flügge,Andreas Kolditz,Jan Siebels,Jan Garrevoet,Kathryn Spiers,Martin Seyrich,Dennis Brückner,Niklas Pyrlik,Johannes Hagemann,Andreas Schropp,Romain Carron,Gerald Falkenberg,Alf Mews,Christian G. Schroer,Tobias Kipp,Michael Stuckelberger +17 more
TL;DR: In this paper, the authors demonstrate, for the first time, the simultaneous assessment of composition, structure, and performance in four-fold multi-modality, using scanning X-ray microscopy of a CIGS solar cell.
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Divide and update: towards single-shot object and probe retrieval for near-field holography.
Johannes Hagemann,Tim Salditt +1 more
TL;DR: An algorithm which requires only two measurements - with and without an object in the beam is devised, which is advantageous if the standard flat-field correction fails and a full ptychographic dataset can not be acquired, since either object or probe are dynamic.
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