• First Interdisciplinary European Symposium on Biomedical Application of X-Ray Phase-Contrast Imaging, 2012, (talk)
  • IEEE Nuclear Science Symposium and Medical Imaging Conference, 2011, (talk)
  • DPG Frühjahrstagung, 2011, (talk)
  • SPIE Medical Imaging Conference, 2011, (poster)
  • Deutsche Physikalische Gesellschaft
  • Medipix
Current research / employment

Inteferometric X-ray imaging is based on Talbot-Lau interferometry. The method provides a differential phase image and a dark field image in addition to the absorption image known from conventional X-ray imaging. The differential phase image provides information about the refractivity of a sample. The dark field image shows the presence of structures in a sample which are below the spatial resolution of the setup.

My research project is focused on the dark field image and its simulation. As part of my diploma thesis I designed and implemented a simulation framework for coherent X-ray imaging based on scalar diffraction theory. In my PHD project I will further enhance the simulation framework with a focus on simulating dark field signals. The simulation has to be evaluated against measurements which are done with the X-ray Talbot-Lau setup at the Erlangen Centre for Astroparticle Physics (ECAP). The simulation will be used to optimize future setups for dark field imaging but also to find better analytical dark field imaging models.

The figure below shows a simulated Talbot fringe pattern in a 50µm by 50µm area for a monochromatic wave field with a photon energy of 25keV. The pattern is disturbed by PMMA micro spheres with a radius of 5µm. The pattern has a periodicity of 2.185µm.

Publications A. Ritter, G. Anton, F. Bayer, K. C. Gödel, G. Pelzer, J. Rieger, T. Weber, A. Zang, T. Michel, Simulation of dark-field imaging of micro-calcifications in human breast tissue with X-ray Talbot-Lau interferometry, Journal of Instrumentation, 9, C05028, (2014)

A. Ritter, P. Bartl, F. Bayer, K. C. Gödel, W. Haas, T. Michel, G. Pelzer, J. Rieger, T. Weber, A. Zang, and G. Anton, Simulation framework for coherent and incoherent X-ray imaging and its application in Talbot-Lau dark-field imaging, Optics Express, 22(19), 23276-23289, (2014)

A. Ritter, , Modified shifted angular spectrum method for numerical propagation at reduced spatial sampling rates, Optics Express, 22(21), 26265-26276, (2014)

A. Ritter, F. Bayer, J. Durst, K. C. Gödel, W. Haas, T. Michel, J. Rieger, T. Weber, L. Wucherer, G. Anton, Simultaneous maximum-likelihood reconstruction for x-ray grating based phase-contrast tomography avoiding intermediate phase retrieval,, [], arXiv:1307.7912, (2013)

A. Ritter, F. Bayer, J. Durst, K. C. Gödel, W. Haas, T. Michel, T. Weber, G. Anton, Investigations on the origin of the darkfield signal, Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), 2011 IEEE, , 2314-2315, (2011)

A. Ritter, P. Bartl, F. Bayer, J. Durst, W. Haas, T. Michel, G. Pelzer, T. Weber, G. Anton, Optimization of differential phase-contrast imaging setups using simulative approaches, Proceedings of SPIE, 7961, , (2011)