Radiation as synthetic spectral diagnostics in the particle- in-cell code PIConGPU

We present in-situ computation of relativistic radiation in the particle- in-cell code PIConGPU that can give both qualitative and quantitative agreement with analytical models and thus has predictive capabilities. This new kind of synthetic spectral diagnostics can be used to infer plasma dynamics with high spatial and temporal resolution.

Our method is based on the far field approximation of Liénard-Wiechert potential. Its direct integration with the highly-scalable GPU framework of PIConGPU allows computing the spectrally and angu- larly resolved radiation for thousands of frequencies, ranging from infrared to x-rays, hundreds of detector positions and billions of particles efficiently. Recent updates allow studying polarization and improve time resolution thus extending the range of applications.

These capabilities are demonstrated using recent simulations of laser wakefield acceleration (LWFA), high harmonics generation during target normal sheath acceleration (TNSA) and the Kelvin-Helmholtz in- stability (KHI).