High-flux ptychographic imaging using the new 55 μm-pixel detector 'Lambda' based on the Medipix3 readout chip

Research output: Contribution to journalArticle


Suitable detection systems that are capable of recording high photon count rates with single-photon detection are instrumental for coherent X-ray imaging. The new single-photon-counting pixel detector 'Lambda' has been tested in a ptychographic imaging experiment on solar-cell nanowires using Kirkpatrick-Baez-focused 13.8 keV X-rays. Taking advantage of the high count rate of the Lambda and dynamic range expansion by the semi-transparent central stop, a high-dynamic-range diffraction signal covering more than seven orders of magnitude has been recorded, which corresponds to a photon flux density of about 105 photons nm-2 s-1 or a flux of ∼1010 photons s-1 on the sample. By comparison with data taken without the semi-transparent central stop, an increase in resolution by a factor of 3-4 is determined: from about 125 nm to about 38 nm for the nanowire and from about 83 nm to about 21 nm for the illuminating wavefield.


  • R. N. Wilke
  • J. Wallentin
  • M. Osterhoff
  • D. Pennicard
  • A. Zozulya
  • M. Sprung
  • T. Salditt
External organisations
  • University of Göttingen
  • German Electron Synchrotron (DESY)
Research areas and keywords


  • coherent diffractive imaging, Lambda detector, Medipix3 chip, phase retrieval, ptychography, semi-transparent beam stop, semi-transparent central stop, solar-cell nanowires
Original languageEnglish
Pages (from-to)552-562
Number of pages11
JournalActa Crystallographica Section A: Foundations and Advances
Publication statusPublished - 2014 Nov 1
Publication categoryResearch
Externally publishedYes