Advancing predictive capabilties of LWFA simulations using PIConGPU: From improved modeling to novel measurement methods via synthetic radiation diagnostics

In a close interplay between particle-in-cell simulations and experimental measurements, we present new insights into the modeling of laser wakefield accelerators and discuss the arising challenges for laboratory diagnostics. These challenges were tackled by developing new methods for determining key parameters of the experiment by studying synthetic radiation diagnostics predicted by simulations.

The combination of an unprecedented experimental campaign studying the parameter dependence of beam loading during LWFA and an accompanying, extensive simulation campaign using the 3D3V particle-in-cell code PIConGPU made it possible to provide unique feedback between experiment and theory. This poster shows the step-by-step improvements through this interplay from the simulation perspective. Quantitatively more accurate methods such as the use of Gauss-Laguerre modes or a variety of ionization models are presented as well as more performant computational procedures.

Only through these improvements it was possible to reproduce the dynamics from the experiment and gain a deeper insight into the self-truncated ionization injection regime.

Moreover, this interplay also revealed the limits of current laboratory diagnostics. Synthetic in-situ radiation diagnostics in PIConGPU spurred the development of new diagnostic methods for experiments. For example, the shift in laser focus position due to self-focusing in the plasma can now be quantified by spectral radiation signatures. Applying these new methods will enable an even more accurate understanding of laser plasma dynamics in experiments in the near future.