Modules used in simS2E and simex_platform

FEL source


The FAST code [Schneidmiller, Yurkov et al. 2012] simulates the production of  x-ray free electron laser radiation. It is not available for download or execution but a selection of x-ray free electron laser radiation simulation data can be obtain from the XFEL Photon Pulses Database at


Wavefront Propagation


WPG is a python code for propagation of x-rays. It provides a wrapper interface to SRW libary.


Documentation and tutorials can be found at


XFEL Installation

For users at European XFEL and DESY, wpg is installed under /afs/ You need to load the correct python module via

module load python/2.7


module load python3/3.4


Source code


WPG resides on github.

SPB-SFX beamline simulations

Day 1 configuration, focal spot size


Photon Matter Interaction



The software suite XRAYPAC [1] provides simulation tools for the interaction of intense x-ray pulses (e.g. delivered from an x-ray free electron laser) and atoms or molecules:

XMDYN is a Monte Carlo–Molecular Dynamics
based particle approach. It generates system trajectories as the realization of the temporal
evolution of the system affected by stochastic damage processes. The initial sample is described as a set of individual atoms in
their neutral ground state. The dynamics of the bound electrons are not calculated. Instead, the occupation number of the atomic orbitals is tracked
(following all intermediate states) for each atom. The electronic configuration can change due to stochastic ionization or inner
shell relaxation events. XMDYN takes into account photoionization and all possible Auger and fluorescent decay channels for
a given electronic configuration by assigning probability rates to the processes. The corresponding decays are exponential
in time, but only one of them occurs in a specific realization. It is chosen based on random number generation (Monte Carlo
block). The required physical parameters (cross section and rate data) are calculated with XATOM, an integrated toolkit for
X-ray and atomic physics applying the ab-initio Hartree-Fock-Slater model.


simex_platform and simS2E contain a demo version of XMDYN. The full version is not available for download or execution.  If you are interested in running the software, please contact Jurek Zoltan at CFEL.



  1.  Z. Jurek, R. Santra, S.-K. Son, and B. Ziaja, XRAYPAC – a software package for modeling x-ray-induced dynamics of matter. In preparation.
  2.  Z. Jurek, S.-K. Son, B. Ziaja and R. Santra, XMDYN and XATOM: versatile simulation tools for quantitative modeling XFEL-induced dynamics of matter. J. Appl. Crystallogr., submitted (2016).
  3.  S.-K. Son, L. Young, and R. Santra, Impact of hollow-atom formation on coherent x-ray scattering at high intensity. Phys. Rev. A 83, 033402 (2011).
  4.  Z. Jurek, G. Faigel, M. Tegze, Dynamics in a cluster under the influence of intense femtosecond hard X-ray pulses. Eur. Phys. J. D 29, 217 (2004).
  5.  B. F. Murphy, T. Osipov, Z. Jurek, L. Fang, S.-K. Son, M. Mucke, J. H. D. Eland, V. Zhaunerchyk, R. Feifel, L. Avaldi, P. Bolognesi, C. Bostedt, J. D. Bozek, J. Grilj, M. Gühr, L. J. Frasinski, J. Glowina, D. T. Ha, K. Hoffmann, E. Kukk, B. K. McFarland, C. Miron, E. Sistrunk, R. J. Squibb, K. Ueda, R. Santra, N. Berrah, Femtosecond X-ray-induced explosion of C60 at extreme intensity. Nat. Commun. 5, 4281 (2014).




PIConGPU is a fully relativistic, many GPGPU, 3D3V particle-in-cell (PIC) code. The Particle-in-Cell algorithm is a central tool in plasma physics. It describes the dynamics of a plasma by computing the motion of electrons and ions in the plasma based on Maxwell's equations.

PIConGPU implements various numerical schemes to solve the PIC cycle. Its features include:

  • a Yee-lattice like grid structure
  • particle pushers that solve the equation of motion for charged particles, e.g. the Boris- and the Vay-Pusher
  • Maxwell field solvers, e.g. Yee's and Lehe's scheme
  • rigorously charge conserving current deposition schemes, proposed by Villasenor-Buneman and Esirkepov
  • macro-particle form factors ranging from NGP (0th order), CIC (1st), TSC(2nd) to PSQ (3rd)

Besides the central PIC algorithm, we developed a wide range of tools and diagnostics, e.g.:

  • online, far-field radiation diagnostics for coherent and incoherent radiation emitted by charged particles
  • full hdf5 restart and dumping capabilities
  • 2D and 3D live view and diagnostics tools

Todays GPUs reach a performance up to TFLOP/s at considerable lower invest and maintenance cost compared to CPU-based compute architectures of similar performance. The latest high-performance systems (TOP500) are enhanced by accelerator hardware that boost their peak performance up to the multi-PFLOP/s level. With its outstanding performance, PIConGPU is one of the finalists of the 2013s Gordon Bell Prize.

PIConGPU is developed and maintained by the Junior Group Computational Radiation Physics at the Institute for Radiation Physics at HZDR in close collaboration with the Center for Information Services and High Performance Computing (ZIH) of the Technical University Dresden (TUD).  Member of the Dresden CUDA Center of Excellence that cooperates on a broad range of scientific CUDA applications, workshops and teaching efforts.



Bussmann, M. et al., Radiative Signatures of the Relativistic Kelvin-Helmholtz Instability. Proceedings of the International Conference on High Performance Computing, Networking, Storage and Analysis SC '13, No. 5, pp. 1-12 (ACM, New York 2013).