Predicting SAXS images beyond single scattering

We present a scalable GPU-based software framework for simulating photon scattering processes of X-ray beams in matter using Monte-Carlo methods. These simulations enable us to predict SAXS signals for experiments at upcoming superlative research facilities like the European XFEL. Often the expected outcome of SAXS experiments is produced by a Fourier Transform of a static 2D electron density distribution. Our new framework provides the opportunity to simulate the probing of femtosecond timescale 3D3V electron dynamics with single and multiple scattering and is extendable by more complex physics processes like laser absorption, atomic excitation and de-excitation to further enhance its predictive capability. As a foundation we use libPMacc, a powerful particle-mesh accelerator library that is also used by PIConGPU, the reportedly fastest fully-relativistic 3D3V particle-in-cell code in the world.