From electron beams to full-scale laser-plasmas -- Obtaining radiation ``sky-maps'' of LWFA within particle-in-cell codes.

Spectra from laser-wakefield acceleration are readily available in experiment, but are challenging to model ab-initio. Yet, beyond the basic properties of synchrotron light sources, the emitted spectra from laser-plasmas include the complete phase-space dynamics and thus are applicable as a powerful tool to quantitatively resolve plasma structures on micrometer and femtosecond scales.

Classical, Liénard-Wiechert-type radiation models that include coherence and polarization properties are based on electron trajectory data, which in full-scale laser-plasmas are on the order of hundreds of TBs to several PBs and require about 10^18 kernel calculations for spectral computation in a single LWFA simulation. Since, such radiation calculations clearly cannot be performed in a post-processing step after a PIC simulation, we include the calculation of these radiation spectra into our multi-GPU particle-in-cell code PIConGPU as a synthetic diagnostic (code is available as open source).

We present current LWFA and laser plasma results, for which we calculated angularly resolved spectra ranging from infrared to X-ray wavelengths. Such an extensive treatment of plasma radiation across billions of macro particles makes it possible to explore temporally resolved plasma radiation spectra on linear and logarithmic photon energy scales over large solid angles ("sky-maps"). These 3D, radiative laser-plasma simulations run on current high-performance GPU clusters and scale up to petaflop performance.