title: Numerical model for tomographic image formation in transmission x-ray microscopy.
abstract: We present a numerical image-formation model for investigating the influence of partial coherence, sample thickness and depth-of-focus on the accuracy of tomographic reconstructions in transmission x-ray microscopes. The model combines wave propagation through the object by finite difference techniques with Fourier methods. We include a ray-tracing model to analyse the origin of detrimental stray light in zone plate-based x-ray microscopes. These models allow optimization of x-ray microscopy systems for quantitative tomographic imaging of thick objects. Results show that both the depth-of-focus and the reconstructed local absorption coefficient are highly dependent on the degree of coherence of the optical system.
authors.affiliation: Biomedical and X-Ray Physics, Department of Applied Physics, KTH Royal Institute of Technology/Albanova, Stockholm, Sweden.
authors.forename: Michael
authors.initials: M
authors.lastname: Bertilson
authors.forename: Olov
authors.initials: O
authors.lastname: von Hofsten
authors.forename: Hans M
authors.initials: HM
authors.lastname: Hertz
authors.forename: Ulrich
authors.initials: U
authors.lastname: Vogt