Penetration, micro-resolution, and scattering were the keywords of x-ray analyses in the 20th century. Over the last 15
years, a great class of coherent imaging techniques has emerged as new tools, allowing for low-dose imaging of biological
specimen on the nanoscale.
Apart from experimental and technical challenges, a better understanding of partially coherent beam propagation is the
key for exploiting the new methods' full performance. We present a simulation framework to calculate the mutual intensity
and the degree of spatial coherence of typical x-ray focusing and filtering devices used at 3rd generation synchrotron
We propose the following modeling scheme: A set of independent point-sources yield independent basic fields, which
are superposed in a stochastic manner; by taking the ensemble average, both partially coherent intensity and degree of
coherence can be obtained from the mutual intensity. By including real structure effects, like height deviations of focusing
mirrors, and vibration of optical components, advanced predictions of x-ray beams can be made. This knowledge is
expected to improve reconstruction results from coherent imaging experiments.
Coherence simulations of focusing mirrors are presented and validated with analytical results as well as with experimental
tests. Coherence filtering by use of x-ray waveguides is shown numerically. We also present first simulations for
partially coherent focusing by compound refractive lenses.