Beamstop-based low-background ptychography to image weakly scattering objects

Juliane Reinhardt, Robert Hoppe, Georg Hofmann, Christian Danvad Damsgaard, Jens Patommel, Christoph Baumbach, Sina Baier, Amélie Rochet, Jan-Dierk Grunwaldt, Gerald Falkenberg, Christian G. Schroer

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

In recent years, X-ray ptychography has been established as a valuable tool for high-resolution imaging. Nevertheless, the spatial resolution and sensitivity in coherent diffraction imaging are limited by the signal that is detected over noise and over background scattering. Especially, coherent imaging of weakly scattering specimens suffers from incoherent background that is generated by the interaction of the central beam with matter along its propagation path in particular close to and inside of the detector. Common countermeasures entail evacuated flight tubes or detector-side beamstops, which improve the experimental setup in terms of background reduction or better coverage of high dynamic range in the diffraction patterns. Here, we discuss an alternative approach: we combine two ptychographic scans with and without beamstop and reconstruct them simultaneously taking advantage of the complementary information contained in the two scans. We experimentally demonstrate the potential of this scheme for hard X-ray ptychography by imaging a weakly scattering object composed of catalytic nanoparticles and provide the analysis of the signal-to-background ratio in the diffraction patterns.
Original languageEnglish
JournalULTRAMICROSCOPY
Volume173
Pages (from-to)52-57
Number of pages6
ISSN0304-3991
DOIs
Publication statusPublished - 2017

Keywords

  • Background scattering
  • Beamstop
  • High resolution
  • Nanoparticles
  • Ptychography
  • Signal-to-noise

Cite this

Reinhardt, J., Hoppe, R., Hofmann, G., Damsgaard, C. D., Patommel, J., Baumbach, C., Baier, S., Rochet, A., Grunwaldt, J-D., Falkenberg, G., & Schroer, C. G. (2017). Beamstop-based low-background ptychography to image weakly scattering objects. ULTRAMICROSCOPY, 173, 52-57. https://doi.org/10.1016/j.ultramic.2016.11.005